Endodontic Retreatment
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Jul 14, 2016
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About This Presentation
Endodontic Retreatment
Slide Content
Endodontic Retreatment
Dr. Nithin Mathew
Dr. Nithin Mathew
Contents
Introduction
Definition
Etiology
Evaluation
Indications & Contraindications
Treatment planning
Nonsurgical Endodontic Retreatment
+ Coronal Access Cavity Preparation
+ Post removal
+ Regaining access to periapical area
Endodontic Retreatment - Dr. Nithin Mathew
+ Removal of separated instruments
+ Management of canal impediments
Repair of perforations
Heat generation
Conclusion
References
Introduction
Definition
Etiology
Evaluation
Indications & Contraindications
Treatment planning
Nonsurgical Endodontic Retreatment
+ Coronal Access Cavity Preparation
+ Post removal
+ Regaining access to periapical area
Endodontic Retreatment - Dr. Nithin Mathew
+ Removal of separated instruments
+ Management of canal impediments
Repair of perforations
Heat generation
Conclusion
References
Introduction
+ Friedman stated that “Most patients can relate to the concept of disease-treatment-healing,
whereas failure, apart from being a negative and relative term, does not imply the necessity to
pursue treatment.”
+ Suggested using the term posttreatment disease to describe those cases that would
previously have been referred to as treatment failures.
+ RCT: success rates : 86% - 98% (Friedman 2003, 2004)
Endodontic Retreatment - Dr. Nithin Mathew
+ Friedman stated that “Most patients can relate to the concept of disease-treatment-healing,
whereas failure, apart from being a negative and relative term, does not imply the necessity to
pursue treatment.”
+ Suggested using the term posttreatment disease to describe those cases that would
previously have been referred to as treatment failures.
+ RCT: success rates : 86% - 98% (Friedman 2003, 2004)
Endodontic Retreatment - Dr. Nithin Mathew
+ Success - defined by the following criteria:
1. Patient should be asymptomatic and be able to function equally well on both sides
2. The periodontium should be healthy, including a normal attachment apparatus
3. Radiographs should demonstrate healing or progressive bone fill overtime
Principles of restorative excellence should be satisfied.
(CJ.Ruddle )
(s)
Endodontic Retreatment - Dr. Nithin Mathew
1. Patient should be asymptomatic and be able to function equally well on both sides
2. The periodontium should be healthy, including a normal attachment apparatus
3. Radiographs should demonstrate healing or progressive bone fill overtime
Principles of restorative excellence should be satisfied.
(CJ.Ruddle )
(s)
Endodontic Retreatment - Dr. Nithin Mathew
Definition
+ A procedure to remove root canal filling materials from the tooth, followed by cleaning,
shaping and obturating the canals.
(GET - AAE )
+ Non surgical retreatment is an endodontic treatment procedure used to remove materials
from the root canal space and, if present, address deficiencies or repair defects that are
pathologic or iatrogenic in origin.
(CJ.Ruddle )
Endodontic Retreatment - Dr. Nithin Mathew
+ A procedure to remove root canal filling materials from the tooth, followed by cleaning,
shaping and obturating the canals.
(GET - AAE )
+ Non surgical retreatment is an endodontic treatment procedure used to remove materials
from the root canal space and, if present, address deficiencies or repair defects that are
pathologic or iatrogenic in origin.
(CJ.Ruddle )
Endodontic Retreatment - Dr. Nithin Mathew
Washington Study
+ Study carried out at the University of Washington, school of Dentistry to evaluate treated
endodontic cases and ascertain their success rate.
Results
+ Periapical repair was frequently not complete for the middle aged and elderly patients within
1 year.
+ Age of the patients also affected the failure rates.
+ Higher for patients in the first decade and sixth decade of life.
+ Lower for patients between second to fifth decade of life.
+ No significant difference in the success rates of cases treated surgically or non-surgically.
(7)
Endodontic Retreatment - Dr. Nithin Mathew
+ Study carried out at the University of Washington, school of Dentistry to evaluate treated
endodontic cases and ascertain their success rate.
Results
+ Periapical repair was frequently not complete for the middle aged and elderly patients within
1 year.
+ Age of the patients also affected the failure rates.
+ Higher for patients in the first decade and sixth decade of life.
+ Lower for patients between second to fifth decade of life.
+ No significant difference in the success rates of cases treated surgically or non-surgically.
(7)
Endodontic Retreatment - Dr. Nithin Mathew
Causes of Failure
Number of Failures
% Failures
Incomplete obturation
Root perforation
External root resorption
Coexistent periodontal-
periradicular lesion
Canal grossly overfilled
or overextended
Canal left unfilled
Developing apical cyst
Adjacent pulpless tooth
Silver point
inadvertently removed
Broken instrument
Accessory canal unfilled
Constant trauma
Perforation, nasal floor
Total failures
58.66
9.61
7.70
5.78
3.85
Number of Failures
% Failures
Incomplete obturation
Root perforation
External root resorption
Coexistent periodontal-
periradicular lesion
Canal grossly overfilled
or overextended
Canal left unfilled
Developing apical cyst
Adjacent pulpless tooth
Silver point
inadvertently removed
Broken instrument
Accessory canal unfilled
Constant trauma
Perforation, nasal floor
Total failures
58.66
9.61
7.70
5.78
3.85
Toronto Study
+ The Toronto Study Project, established in 1993,
+ Was a continuous prospective investigation of the 4 to 6-year outcome of endodontic
treatment performed by graduate endodontics students in a university clinic environment.
+ This modular design provides cumulative data with the completion of each successive phase,
with the aim of amassing a sufficient sample to study the prognostic value of various factors.
Endodontic Retreatment - Dr. Nithin Mathew
+ The Toronto Study Project, established in 1993,
+ Was a continuous prospective investigation of the 4 to 6-year outcome of endodontic
treatment performed by graduate endodontics students in a university clinic environment.
+ This modular design provides cumulative data with the completion of each successive phase,
with the aim of amassing a sufficient sample to study the prognostic value of various factors.
Endodontic Retreatment - Dr. Nithin Mathew
+ Strindberg related treatment outcomes to biologic and therapeutic factors.
+ Some of the factors that influence outcome include the
+ Presence of apical pathosis
+ Extension of the obturation (short or long)
+ Quality and technique of obturation
+ Observation period
+ Type of intracanal medication and bacterial status of the canal before obturation
Endodontic Retreatment - Dr. Nithin Mathew
+ Some of the factors that influence outcome include the
+ Presence of apical pathosis
+ Extension of the obturation (short or long)
+ Quality and technique of obturation
+ Observation period
+ Type of intracanal medication and bacterial status of the canal before obturation
Endodontic Retreatment - Dr. Nithin Mathew
Causes for Failure
Preoperative causes
+ Incorrect oral examination & misinterpretation
+ Sinus tract, pain, vitality test, periodontal problems
+ Misinterpretation of radiographs
+ Odontogenic, developmental lesions, anatomic landmarks
+ Physical injury
+» Improper case selection
+ Patient cooperation
+ Technical difficulties
+ Patient systemic condition
+» Grossly destructed teeth
+ Root resorption
+ Inadequate sterilization of instruments
Endodontic Retreatment - Dr. Nithin Mathew
Preoperative causes
+ Incorrect oral examination & misinterpretation
+ Sinus tract, pain, vitality test, periodontal problems
+ Misinterpretation of radiographs
+ Odontogenic, developmental lesions, anatomic landmarks
+ Physical injury
+» Improper case selection
+ Patient cooperation
+ Technical difficulties
+ Patient systemic condition
+» Grossly destructed teeth
+ Root resorption
+ Inadequate sterilization of instruments
Endodontic Retreatment - Dr. Nithin Mathew
Operative causes
+ Failure to obtain Biomechanical objectives
+ Access preparation
+ Perforation
+ Underextended preparation
+ Overextended preparation
+ Canal preparation
+ Perforations
+ Ledge formation
+ Canal blockage
+ Instrument separation & foreign objects
Endodontic Retreatment - Dr. Nithin Mathew
+ Failure to obtain Biomechanical objectives
+ Access preparation
+ Perforation
+ Underextended preparation
+ Overextended preparation
+ Canal preparation
+ Perforations
+ Ledge formation
+ Canal blockage
+ Instrument separation & foreign objects
Endodontic Retreatment - Dr. Nithin Mathew
+ Failure To Obtain Biological Objectives
+ Removal Of Potential Irritants From
+ Coronal Portion
+ Root Canal System
* Periapical Tissues
+ Defective Obturation
+ Overextended Filling
+ Underextended Filling
+ Periodontal Involvement- Lateral And Accessory Canals
Endodontic Retreatment - Dr. Nithin Mathew
+ Removal Of Potential Irritants From
+ Coronal Portion
+ Root Canal System
* Periapical Tissues
+ Defective Obturation
+ Overextended Filling
+ Underextended Filling
+ Periodontal Involvement- Lateral And Accessory Canals
Endodontic Retreatment - Dr. Nithin Mathew
Post-Operative causes
+ Trauma & fracture
+ Impaired periapical healing
+ Superimposed Non-endodontic involvement
+ Excessive orthodontic forces, periodontal disease
+ Poor post-endodontic restoration
y _ Endodontic Retreatment - Dr. Nithin Mathew
+ Trauma & fracture
+ Impaired periapical healing
+ Superimposed Non-endodontic involvement
+ Excessive orthodontic forces, periodontal disease
+ Poor post-endodontic restoration
y _ Endodontic Retreatment - Dr. Nithin Mathew
+ In order to plan treatment effectively, the clinician may place the etiologic factors into four
groups :
+ Persistent or reintroduced intraradicular microorganisms
+ Extraradicular infection
+ Foreign body reaction
+ True cysts
Endodontic Retreatment - Dr. Nithin Mathew
groups :
+ Persistent or reintroduced intraradicular microorganisms
+ Extraradicular infection
+ Foreign body reaction
+ True cysts
Endodontic Retreatment - Dr. Nithin Mathew
Persistent or Reintroduced Intraradicular Microorganisms
+ RCspace and dentinal tubules
+ Contaminated with microorganisms or their by-products
+ Pathogens are allowed to contact the Periradicular tissues
+ Persistent or reintroduced microorganisms : Major cause of posttreatment disease
+ Iatrogenic complications : Ledge/instrument separation : Persistence of bacteria
+ Previous RCT : Short Obturation : Untreated necrotic infected pulp
+ Classic “failed” root canal therapy (Sundqvist et al 1998)
Endodontic Retreatment - Dr. Nithin Mathew
+ RCspace and dentinal tubules
+ Contaminated with microorganisms or their by-products
+ Pathogens are allowed to contact the Periradicular tissues
+ Persistent or reintroduced microorganisms : Major cause of posttreatment disease
+ Iatrogenic complications : Ledge/instrument separation : Persistence of bacteria
+ Previous RCT : Short Obturation : Untreated necrotic infected pulp
+ Classic “failed” root canal therapy (Sundqvist et al 1998)
Endodontic Retreatment - Dr. Nithin Mathew
Persistent or Reintroduced Intraradicular Microorganisms
+ If the resultant microbial ecosystem is amenable to bacterial survival, a lesion may not heal
and root canal treatment would be deemed to have failed.
+ If the root canal filling fails to provide a complete seal, seepage of tissue fluids could
theoretically provide a substrate for bacterial growth.
+ Relationship between the quality of the coronal restoration and the root canal obturation
1° No matter what is used to obturate the canals, if the coronal seal is compromised, it may
I lead to failure.
|
Endodontic Retreatment - Dr
+ If the resultant microbial ecosystem is amenable to bacterial survival, a lesion may not heal
and root canal treatment would be deemed to have failed.
+ If the root canal filling fails to provide a complete seal, seepage of tissue fluids could
theoretically provide a substrate for bacterial growth.
+ Relationship between the quality of the coronal restoration and the root canal obturation
1° No matter what is used to obturate the canals, if the coronal seal is compromised, it may
I lead to failure.
|
Endodontic Retreatment - Dr
Extraradicular Infection
+ Bacteria invade periradicular tissue either by
+ Direct spread of infection from the root canal space
+ Extrusion of infected dentin chips
+ Contamination with overextended, infected endodontic instruments.
+ Host response : destroy organisms
+ Some microorganisms : resist the immune defenses and persist in the periradicular tissues
+ 2 species : Actinomyces israelii and Propionibacterium propionicum
+ Exist in the periapical tissues and may prevent healing after root canal therapy.
Endodontic Retreatment - Dr. Nithin Mathew
+ Bacteria invade periradicular tissue either by
+ Direct spread of infection from the root canal space
+ Extrusion of infected dentin chips
+ Contamination with overextended, infected endodontic instruments.
+ Host response : destroy organisms
+ Some microorganisms : resist the immune defenses and persist in the periradicular tissues
+ 2 species : Actinomyces israelii and Propionibacterium propionicum
+ Exist in the periapical tissues and may prevent healing after root canal therapy.
Endodontic Retreatment - Dr. Nithin Mathew
True Cysts
+ Incidence of periapical cysts : 15% to 42% of all periapical lesions
+ 2 types of periapical cysts :
+ Periapical true cyst
+ Periapical pocket cyst.
+ True cysts
+ Contained cavity or lumen within a continuous epithelial lining : isolated from the tooth
+ Pocket cysts
+ Lumen is open to the root canal of the affected tooth.
+ True cysts, due to their self-sustaining nature, probably do not heal following nonsurgical
endodontic therapy : Usually require surgical enucleation E]
Endodontic Retreatment - Dr. Nithin Mathew
+ Incidence of periapical cysts : 15% to 42% of all periapical lesions
+ 2 types of periapical cysts :
+ Periapical true cyst
+ Periapical pocket cyst.
+ True cysts
+ Contained cavity or lumen within a continuous epithelial lining : isolated from the tooth
+ Pocket cysts
+ Lumen is open to the root canal of the affected tooth.
+ True cysts, due to their self-sustaining nature, probably do not heal following nonsurgical
endodontic therapy : Usually require surgical enucleation E]
Endodontic Retreatment - Dr. Nithin Mathew
Methods of Evaluation
Endodontic Retreatment - Dr. Nithin Mathew
Endodontic Retreatment - Dr. Nithin Mathew
Clinical Criteria for Success
+ According to Bender et al
+ Absence of pain and swelling
+ Disappearance of sinus tract
+ No loss of function
+ No evidence of soft tissue destruction, including probing defects
+ Persistent findings like (swelling or sinus tract) indicates failures
Endodontic Retreatment - Dr. Nithin Mathew
+ According to Bender et al
+ Absence of pain and swelling
+ Disappearance of sinus tract
+ No loss of function
+ No evidence of soft tissue destruction, including probing defects
+ Persistent findings like (swelling or sinus tract) indicates failures
Endodontic Retreatment - Dr. Nithin Mathew
+ To make a correct diagnosis, the clinician must
+ Rule out non-odontogenic etiology
+ Perform all of the appropriate tests
+ Properly interpret the patient's responses to these tests
+ Derive at a definitive diagnosis
+ Decide on treatment options
Endodontic Retreatment - Dr. Nithin Mathew
+ Rule out non-odontogenic etiology
+ Perform all of the appropriate tests
+ Properly interpret the patient's responses to these tests
+ Derive at a definitive diagnosis
+ Decide on treatment options
Endodontic Retreatment - Dr. Nithin Mathew
+ Subjective assessment
+ Previous treatment : aseptic techniques
+ Objective assessment
+ Visual extraoral and intraoral examination
+ Aided by magnification and illumination
+ A thorough periodontal evaluation
+ Comparative : pulpal and Periradicular status.
+ Percussion, bite, and palpation
+ Pulp vitality tests : less value in endo treated tooth
Endodontic Retreatment - Dr. Nithin Mathew
+ Previous treatment : aseptic techniques
+ Objective assessment
+ Visual extraoral and intraoral examination
+ Aided by magnification and illumination
+ A thorough periodontal evaluation
+ Comparative : pulpal and Periradicular status.
+ Percussion, bite, and palpation
+ Pulp vitality tests : less value in endo treated tooth
Endodontic Retreatment - Dr. Nithin Mathew
Radiographic Assessment
+ Radiographic assessment is obligatory
+ In cases with previous endodontic therapy, radiographs are useful in
+ Evaluation of caries, defective restorations, periodontal health
* Quality of the obturation
+ Existence of missed canals
+ Impediments to instrumentation
+ Periradicular pathosis
+ Perforations, fractures, resorptions
+ Canal anatomy
+ Multiple angulated films should be used to determine endodontic etiologies
+ CBCT : Untreated canals, root fractures, resorption
Endodontic Retreatment - Dr. Nithin Mathew
+ Radiographic assessment is obligatory
+ In cases with previous endodontic therapy, radiographs are useful in
+ Evaluation of caries, defective restorations, periodontal health
* Quality of the obturation
+ Existence of missed canals
+ Impediments to instrumentation
+ Periradicular pathosis
+ Perforations, fractures, resorptions
+ Canal anatomy
+ Multiple angulated films should be used to determine endodontic etiologies
+ CBCT : Untreated canals, root fractures, resorption
Endodontic Retreatment - Dr. Nithin Mathew
+ Classified as
+ Success
+ Failure
+ Questionable
+ Success
+ Absence of a radiographic resorptive apical lesion.
+ Alesion present at the time of treatment has resolved or that lesion not present at the time
of treatment has not developed.
+ So success is evident by an eliminated or non-developed area of rarefaction after a post
treatment interval of 1 to 4 years.
(2s)
Endodontic Retreatment - Dr. Nithin Mathew
+ Success
+ Failure
+ Questionable
+ Success
+ Absence of a radiographic resorptive apical lesion.
+ Alesion present at the time of treatment has resolved or that lesion not present at the time
of treatment has not developed.
+ So success is evident by an eliminated or non-developed area of rarefaction after a post
treatment interval of 1 to 4 years.
(2s)
Endodontic Retreatment - Dr. Nithin Mathew
+ Failure
+ Persistence or development of radiographically evident pathosis.
+ Radiolucent lesion that has enlarged, has persisted or has developed since the
treatment.
+ Questionable
+ Astate of uncertainty
+ Situation (radiolucent lesion) has neither become worse not significantly improved
+ A questionable status reverts to failure if the situation (non-resolution) continues,
generally after a period of 1 year.
Endodontic Retreatment - Dr. Nithin Mathew
+ Persistence or development of radiographically evident pathosis.
+ Radiolucent lesion that has enlarged, has persisted or has developed since the
treatment.
+ Questionable
+ Astate of uncertainty
+ Situation (radiolucent lesion) has neither become worse not significantly improved
+ A questionable status reverts to failure if the situation (non-resolution) continues,
generally after a period of 1 year.
Endodontic Retreatment - Dr. Nithin Mathew
Histologic Examination
+ Evidenced by reconstitution of periapical structures and an absence of inflammation.
+ Routine histologic evaluation of periapical tissues on patients is impractical.
+ Thus, clinical findings (signs and symptoms as well as radiographic findings) are the only
means of assessing success and failure.
Endodontic Retreatment - Dr. Nithin Mathew
+ Evidenced by reconstitution of periapical structures and an absence of inflammation.
+ Routine histologic evaluation of periapical tissues on patients is impractical.
+ Thus, clinical findings (signs and symptoms as well as radiographic findings) are the only
means of assessing success and failure.
Endodontic Retreatment - Dr. Nithin Mathew
When to evaluate
+ Lack of consensus on the criteria for assessing success or failure, the length of time necessary
for adequate post-operative follow-up also remains controversial.
+ Suggested period : 6 months - 4 years
Endodontic Retreatment - Dr. Nithin Mathew
+ Lack of consensus on the criteria for assessing success or failure, the length of time necessary
for adequate post-operative follow-up also remains controversial.
+ Suggested period : 6 months - 4 years
Endodontic Retreatment - Dr. Nithin Mathew
Indications
+ Periapical radiolucencies even after 4 years
+ Tenderness to percussion
+ Apical pain to pressure
+ Fistula formation
+ Swelling of soft tissue
+ Incomplete root canal filling - for prosthetic restoration even being asymptomatic
Endodontic Retreatment - Dr. Nithin Mathew
+ Periapical radiolucencies even after 4 years
+ Tenderness to percussion
+ Apical pain to pressure
+ Fistula formation
+ Swelling of soft tissue
+ Incomplete root canal filling - for prosthetic restoration even being asymptomatic
Endodontic Retreatment - Dr. Nithin Mathew
+ Vertical fracture
+ Poor periodontal status
Non restorable teeth
Access is difficult
Patients with TMJ dislocation problems
Resorption
Anatomical limitations
Non strategic position
Endodontic Retreatment - Dr. Nithin Mathew
+ Poor periodontal status
Non restorable teeth
Access is difficult
Patients with TMJ dislocation problems
Resorption
Anatomical limitations
Non strategic position
Endodontic Retreatment - Dr. Nithin Mathew
Treatment Plan
+ The patient harbouring true endodontic posttreatment disease has four basic options for
treatment:
+ Do nothing
+ Extract the tooth
+ Nonsurgical retreatment
+ Surgical retreatment
Endodontic Retreatment - Dr. Nithin Mathew
+ The patient harbouring true endodontic posttreatment disease has four basic options for
treatment:
+ Do nothing
+ Extract the tooth
+ Nonsurgical retreatment
+ Surgical retreatment
Endodontic Retreatment - Dr. Nithin Mathew
NONSURGICAL ENDODONTIC RETREATMENT
+ Primary goal: regain access to the periapical area (endotreated tooth)
+ Principals of endodontic therapy followed : completion of case
+ Coronal access needs to be completed
+ All previous root-filling materials need to be removed
+ Canal obstructions must be managed
+ Impediments to achieving full working length must be overcome
+ Cleaning and shaping procedures : for effective obturation and case completion
Endodontic Retreatment - Dr. Nithin Mathew
+ Primary goal: regain access to the periapical area (endotreated tooth)
+ Principals of endodontic therapy followed : completion of case
+ Coronal access needs to be completed
+ All previous root-filling materials need to be removed
+ Canal obstructions must be managed
+ Impediments to achieving full working length must be overcome
+ Cleaning and shaping procedures : for effective obturation and case completion
Endodontic Retreatment - Dr. Nithin Mathew
NonSurgical Endodontic Retreatment : Coronal Disassembly
+ Retreatment access is called coronal disassembly
+ Removal of the coronal restoration includes
+ Full coverage restoration
+ Core build-up material
+ Post placed into the canal
+ Advised to remove the existing coronal restoration if it has
+ Poor marginal adapatation
+ Secondary caries
+ To avoid procedural errors
+ To maintain form, function and esthetics
Endodontic Retreatment - Dr. Nithin Mathew
+ Retreatment access is called coronal disassembly
+ Removal of the coronal restoration includes
+ Full coverage restoration
+ Core build-up material
+ Post placed into the canal
+ Advised to remove the existing coronal restoration if it has
+ Poor marginal adapatation
+ Secondary caries
+ To avoid procedural errors
+ To maintain form, function and esthetics
Endodontic Retreatment - Dr. Nithin Mathew
+ Re-access to the pulp chamber through the existing restoration
+ If itis judged to be functionally designed, well fitting and esthetically pleasing.
+ Removal is based on whether additional access is required to facilitate disassembly and
retreatment.
+ Preparation type
+ Restoration design and strength
+ Restorative material used
+ Cementing agents
+ Removal device
Endodontic Retreatment - Dr. Nithin Mathew
+ If itis judged to be functionally designed, well fitting and esthetically pleasing.
+ Removal is based on whether additional access is required to facilitate disassembly and
retreatment.
+ Preparation type
+ Restoration design and strength
+ Restorative material used
+ Cementing agents
+ Removal device
Endodontic Retreatment - Dr. Nithin Mathew
+ Coronal disassembly devices:
+ Grasping instruments
+ Percussive instruments
+ Active instruments
Endodontic Retreatment - Dr. Nithin Mathew
+ Grasping instruments
+ Percussive instruments
+ Active instruments
Endodontic Retreatment - Dr. Nithin Mathew
Grasping instruments
+ Appling inward pressure on two opposing handles
+ Proportionally increases the instrument's ability to grip a restoration.
+ Strong purchase while reducing dangerous slippage.
+ Handle pressure OL Instrument ability to grip restoration
+ Eg: Ss
+ Trident crown Placer/ remover
+ KY. Pliers
+ Wynman Crown Gripper
+ Removing provisional restorations
Endodontic Retreatment - Dr. Nithin Mathew
+ Appling inward pressure on two opposing handles
+ Proportionally increases the instrument's ability to grip a restoration.
+ Strong purchase while reducing dangerous slippage.
+ Handle pressure OL Instrument ability to grip restoration
+ Eg: Ss
+ Trident crown Placer/ remover
+ KY. Pliers
+ Wynman Crown Gripper
+ Removing provisional restorations
Endodontic Retreatment - Dr. Nithin Mathew
Percussive instruments
+ Selective and controlled percussive removal force
+ Deliver impact directly to restoration or indirectly to another securely engaged prosthetic
removal device
+ Eg:
+ Ultrasonic Energy
+ Crown- A-Matic (Peerless) /
+ Coronaflex
+ Removal or provisional & definitive restoration
7 (»)
Endodontic Retreatment - Dr. Nithin Mathew
+ Selective and controlled percussive removal force
+ Deliver impact directly to restoration or indirectly to another securely engaged prosthetic
removal device
+ Eg:
+ Ultrasonic Energy
+ Crown- A-Matic (Peerless) /
+ Coronaflex
+ Removal or provisional & definitive restoration
7 (»)
Endodontic Retreatment - Dr. Nithin Mathew
Active instruments
+ Actively engage a restoration, enabling a specific dislodgement force to potentially lift off the
prosthesis.
+ Requires a small occlusal window to facilitate mechanical action of the instrument.
+ Creates a lifting force : separating crown & preparation
EE:
+ Metalift
+ Kline Crown Remover
+ Higa Bridge Remover
Endodontic Retreatment - Dr. Nithin Mathew
+ Actively engage a restoration, enabling a specific dislodgement force to potentially lift off the
prosthesis.
+ Requires a small occlusal window to facilitate mechanical action of the instrument.
+ Creates a lifting force : separating crown & preparation
EE:
+ Metalift
+ Kline Crown Remover
+ Higa Bridge Remover
Endodontic Retreatment - Dr. Nithin Mathew
Post Removal
1 * Common to encounter a post : increase in frequency
+ Factors influencing post removal
» Operator judgment
+ Training & Experience
+ Technique & devices
+ Post type - parallel/ tapered, active/ passive
+ Cementing agent
y _ Endodontic Retreatment - Dr. Nithin Mathew
1 * Common to encounter a post : increase in frequency
+ Factors influencing post removal
» Operator judgment
+ Training & Experience
+ Technique & devices
+ Post type - parallel/ tapered, active/ passive
+ Cementing agent
y _ Endodontic Retreatment - Dr. Nithin Mathew
+ Steps:
Core restorative material is removed
A less aggressive instrument, such as a tapered bur in a slow-speed handpiece or a
tapered, midsized ultrasonic tip, should be used to remove the last of the embedding
core material.
+ Magnification and illumination
Minimal restorative material remaining, smaller sized ultrasonic instrument should be
used
+ To minimize the risk of removing unnecessary tooth structure
Thinning of the post.
More post that is left, the more options for removal
More tooth structure that is left, the more options for restoration
Endodontic Retreatment - Dr. Nithin Mathew
Core restorative material is removed
A less aggressive instrument, such as a tapered bur in a slow-speed handpiece or a
tapered, midsized ultrasonic tip, should be used to remove the last of the embedding
core material.
+ Magnification and illumination
Minimal restorative material remaining, smaller sized ultrasonic instrument should be
used
+ To minimize the risk of removing unnecessary tooth structure
Thinning of the post.
More post that is left, the more options for removal
More tooth structure that is left, the more options for restoration
Endodontic Retreatment - Dr. Nithin Mathew
|
I + Techniques for post removal :
+ Ultrasonic vibration
+ Rotosonic vibration
+ Mechanical devices
y _ Endodontic Retreatment - Dr. Nithin Mathew
I + Techniques for post removal :
+ Ultrasonic vibration
+ Rotosonic vibration
+ Mechanical devices
y _ Endodontic Retreatment - Dr. Nithin Mathew
Ultrasonic vibration
+ Piezo electric ultrasonic systems in conjuction with specific instruments.
+ Instrument at the interface between the post and the tooth (the cement line)
+ Constantly moved around the circumference of the post
+ Disrupt the cement structure along the post/canal wall interface and decrease post
retention
+ Tip should be removed from the access every 10 to 15 seconds
+ To allow the use of an air/water syringe
+ To clean the area of debris
+ To reduce the temperature produced that could potentially cause damage to the
periradicular tissues.
Endodontic Retreatment - Dr
+ Piezo electric ultrasonic systems in conjuction with specific instruments.
+ Instrument at the interface between the post and the tooth (the cement line)
+ Constantly moved around the circumference of the post
+ Disrupt the cement structure along the post/canal wall interface and decrease post
retention
+ Tip should be removed from the access every 10 to 15 seconds
+ To allow the use of an air/water syringe
+ To clean the area of debris
+ To reduce the temperature produced that could potentially cause damage to the
periradicular tissues.
Endodontic Retreatment - Dr
Ultrasonic vibration
+ Area around the post may be flooded with a solvent (chloroform) prior to activating the
ultrasonic instrument
+ Dissolve the cement around the post
+ Ultrasonic energy produced will set up shock waves in the solvent and make it penetrate
deeper into the canal space, exerting a faster solvent action on the cement
One study has shown that heat generation with ultrasonic vibration may help to decrease
retention of resin cemented posts. (Garido et al 2004)
+ But concern for heat generated periodontal ligament damage. (Swartz et al 2004)
Endodontic Retreatment - Dr. Nithin Mathew
+ Area around the post may be flooded with a solvent (chloroform) prior to activating the
ultrasonic instrument
+ Dissolve the cement around the post
+ Ultrasonic energy produced will set up shock waves in the solvent and make it penetrate
deeper into the canal space, exerting a faster solvent action on the cement
One study has shown that heat generation with ultrasonic vibration may help to decrease
retention of resin cemented posts. (Garido et al 2004)
+ But concern for heat generated periodontal ligament damage. (Swartz et al 2004)
Endodontic Retreatment - Dr. Nithin Mathew
Rotosonic vibration
+ Rotosonics is a method to potentially loosen and remove a fully exposed post.
+ The regular tip Roto-pro Bur (Ellman International, Hewlett, NY) is a high-speed, friction
grip bur whose six sides utilize six edges which when rotated in one revolution produce six
vibrations per revolution.
+ Rotated at 200,000 rpm, it produces 1.2 million vibrations per minute.
Endodontic Retreatment - Dr. Nithin Mathew
+ Rotosonics is a method to potentially loosen and remove a fully exposed post.
+ The regular tip Roto-pro Bur (Ellman International, Hewlett, NY) is a high-speed, friction
grip bur whose six sides utilize six edges which when rotated in one revolution produce six
vibrations per revolution.
+ Rotated at 200,000 rpm, it produces 1.2 million vibrations per minute.
Endodontic Retreatment - Dr. Nithin Mathew
Mechanical Devices
+ If retention reduction does not remove the post, some form of vice is needed to pull the post
from its preparation.
+ Gonon post removing system (Thomas Extracteur De Pivots,
Ffdmpneumat, Bourge, France)
+ Effective instrument for removing parallel or tapered,
nonactive preformed posts
+ Kit utilizes a hollow trephine bur aligned with the long axis of
the post and placed over its exposed end
Endodontic Retreatment - Dr. Nithin Mathew
+ If retention reduction does not remove the post, some form of vice is needed to pull the post
from its preparation.
+ Gonon post removing system (Thomas Extracteur De Pivots,
Ffdmpneumat, Bourge, France)
+ Effective instrument for removing parallel or tapered,
nonactive preformed posts
+ Kit utilizes a hollow trephine bur aligned with the long axis of
the post and placed over its exposed end
Endodontic Retreatment - Dr. Nithin Mathew
Fractured post ina
lower incisor
Trephine bur milling
the post
Ultrasonic exposure of
the post
Extraction device tapping a
thread onto the post
Domer bur creating a shape that
the trephine bur can engage
Vice applied. Turning the screw on the
vice opens the jaws, creating the
extraction force.
lower incisor
Trephine bur milling
the post
Ultrasonic exposure of
the post
Extraction device tapping a
thread onto the post
Domer bur creating a shape that
the trephine bur can engage
Vice applied. Turning the screw on the
vice opens the jaws, creating the
extraction force.
+ This method is effective because
+ All the force is applied to the bond between the tooth and the
post, ideally in the long axis of the root.
+ Drawbacks:
+ Size of the vice that can make access in the molar region and between crowded lower
incisors difficult.
+ If the extraction force applied is not directed in the long axis of the root, root fracture
may occur
Endodontic Retreatment - Dr. Nithin Mathew
+ All the force is applied to the bond between the tooth and the
post, ideally in the long axis of the root.
+ Drawbacks:
+ Size of the vice that can make access in the molar region and between crowded lower
incisors difficult.
+ If the extraction force applied is not directed in the long axis of the root, root fracture
may occur
Endodontic Retreatment - Dr. Nithin Mathew
+ Other Post Removal Systems (PRS) :
+ Thomas Screw Post Removal Kit
+ Ruddle Post Removal System
+ Universal Post Remover
+ JS Post Extractor
+ Post Puller (Eggler Post Remover)
Endodontic Retreatment - Dr. Nithin Mathew
+ Thomas Screw Post Removal Kit
+ Ruddle Post Removal System
+ Universal Post Remover
+ JS Post Extractor
+ Post Puller (Eggler Post Remover)
Endodontic Retreatment - Dr. Nithin Mathew
Removal Of Fibre Posts
+ Ultrasonic / gonon kit : none works for fibre post removal
+ Use of a high-speed bur to channel down through the post may result in a high rate of root
perforation.
+ A new bur Gyrotip has been designed for the specific purpose of
removing fiber-reinforced composite posts.
+ Drills consist of a heat generating tip designed to soften the matrix
that binds the fibers within the fiber-reinforced post.
Endodontic Retreatment - Dr
+ Ultrasonic / gonon kit : none works for fibre post removal
+ Use of a high-speed bur to channel down through the post may result in a high rate of root
perforation.
+ A new bur Gyrotip has been designed for the specific purpose of
removing fiber-reinforced composite posts.
+ Drills consist of a heat generating tip designed to soften the matrix
that binds the fibers within the fiber-reinforced post.
Endodontic Retreatment - Dr
Fibers within the post are parallel, which assists the axial travel of the
drill through the center of the post.
Fluted zone of the drill allows the fibers to be safely removed, creating
access to the root canal filling.
Above the fluted zone, a layer of plasma bonded silica carbide reduces
the heat generation
This abrasive zone also provides for a straight-line access preparation
and facilitates the placement of a new post
treatment - Dr. Nithin Mathew
drill through the center of the post.
Fluted zone of the drill allows the fibers to be safely removed, creating
access to the root canal filling.
Above the fluted zone, a layer of plasma bonded silica carbide reduces
the heat generation
This abrasive zone also provides for a straight-line access preparation
and facilitates the placement of a new post
treatment - Dr. Nithin Mathew
Ceramic and Zirconium posts : Impossible to retrieve.
They are more fragile than metal posts, and though ceramic posts may be removed by
grinding them away with a bur.
+ High risk of root perforation
Zirconium has a hardness approaching that of diamond and cannot be removed by this
method.
Removal of a fractured zirconia post by ultrasonic vibration has been found to cause
temperature rise of the post and on the root surface
Great white Z bur (SS White) : For Zirconia Posts
They are more fragile than metal posts, and though ceramic posts may be removed by
grinding them away with a bur.
+ High risk of root perforation
Zirconium has a hardness approaching that of diamond and cannot be removed by this
method.
Removal of a fractured zirconia post by ultrasonic vibration has been found to cause
temperature rise of the post and on the root surface
Great white Z bur (SS White) : For Zirconia Posts
Potential Complications of Post Removal
+ Fracture of the tooth, leaving the tooth nonrestorable
+ Toot perforation
+ Post breakage
+ Inability to remove the post
+ An additional concern is ultrasonically generated heat damage to the periodontium.
Endodontic Retreatment - Dr. Nithin Mathew
+ Fracture of the tooth, leaving the tooth nonrestorable
+ Toot perforation
+ Post breakage
+ Inability to remove the post
+ An additional concern is ultrasonically generated heat damage to the periodontium.
Endodontic Retreatment - Dr. Nithin Mathew
Gutta Percha Removal
+ Initially removed from the canal in the coronal one third, then the middle one third and
finally eliminated from apical one third.
Following methods or combination of methods are used.
+ K-files or H-files
+ Gutta-percha solvent
+ Combination of paper points and gutta-percha solvent
+ Rotary instruments
+ Specialized rotary instruments designed for retreatment
+ Heat transfer devices
+ Soft tissue laser
Endodontic Retreatment - Dr. Nithin Mathew
+ Initially removed from the canal in the coronal one third, then the middle one third and
finally eliminated from apical one third.
Following methods or combination of methods are used.
+ K-files or H-files
+ Gutta-percha solvent
+ Combination of paper points and gutta-percha solvent
+ Rotary instruments
+ Specialized rotary instruments designed for retreatment
+ Heat transfer devices
+ Soft tissue laser
Endodontic Retreatment - Dr. Nithin Mathew
+ K&H files
+ Allows for a gross removal of gutta-percha especially from large canals, which
are poorly compacted allowing files to bypass the obturating material and
‘bite’ into the mass
+ Micro-debriders (Dentsply Maillefer) are small files having 90-degree bend at
the working end and an attached handle.
+ It may also be used to substitute standard K-files and H-files.
'etreatment - Dr. Nithin Mathew
+ Allows for a gross removal of gutta-percha especially from large canals, which
are poorly compacted allowing files to bypass the obturating material and
‘bite’ into the mass
+ Micro-debriders (Dentsply Maillefer) are small files having 90-degree bend at
the working end and an attached handle.
+ It may also be used to substitute standard K-files and H-files.
'etreatment - Dr. Nithin Mathew
Solvents
Chloroform
Methyl chloroform
Eucalyptol oil
Halothane
Turpentine
Xylene
Orange wood oil
+ Chloroform
+ Proven to be most successful
+ Evaporates rapidly
+ Potential carcinogenicity
Endodontic Retreatment - Dr. Nithin Mathew
Chloroform
Methyl chloroform
Eucalyptol oil
Halothane
Turpentine
Xylene
Orange wood oil
+ Chloroform
+ Proven to be most successful
+ Evaporates rapidly
+ Potential carcinogenicity
Endodontic Retreatment - Dr. Nithin Mathew
+ Eucalyptol:
+ Less irritating than chloroform
+ Antibacterial
+ Least effective GP solvent
+ Xylene:
+ Highly toxic
+ Evaporates too slowly
+ Dissolving effect less than chloroform
* Orange wood oil:
+ Contraindicated - over extended fillings
+ Halothane:
+ Longer time for dissolving than chloroform
Endodontic Retreatment - Dr. Nithin Mathew
+ Less irritating than chloroform
+ Antibacterial
+ Least effective GP solvent
+ Xylene:
+ Highly toxic
+ Evaporates too slowly
+ Dissolving effect less than chloroform
* Orange wood oil:
+ Contraindicated - over extended fillings
+ Halothane:
+ Longer time for dissolving than chloroform
Endodontic Retreatment - Dr. Nithin Mathew
Rotary Removal
= |i
+ GPX Gutta-percha Remover (Prestige Dental)
Specially designed file %
Slowspeed handpiece. ’ 5 |
Plasticizes by frictional heat and facilitates its removal by its H-file like
flute design.
+ ISO 25-50
+ Recently introduced NiTi GPX -curved canals
'etreatment - Dr. Nithin Mathew
= |i
+ GPX Gutta-percha Remover (Prestige Dental)
Specially designed file %
Slowspeed handpiece. ’ 5 |
Plasticizes by frictional heat and facilitates its removal by its H-file like
flute design.
+ ISO 25-50
+ Recently introduced NiTi GPX -curved canals
'etreatment - Dr. Nithin Mathew
PNT. Stainless Steel
Packaging unit 6 6 6 6 6 6
Color code e e e e e, e.
Size == DO num. 025 050 055 040 015 050
121 270. 2001 2002 2003 2004 2005 2006
Assortment 2000
cr features a spiraled vent through which gutta-percha is extruded as its plastertzed
rom mictionat heat.
Nill GPX". Nickel Titantum Nite! ==
e
Packaging unit 6 6 6 6 6 6
Color code . o... © »
Size == DO vi00mm 025 050 055 oo 045 050
1-21 270, 1901 1902 1003 1004 1005 1006
Assortment 1900
A laten-type nickel titanium alloy instrument for use on low speed hand pleces. CPXT™#
features a spiraled vent through which gutta-percha is extruded as I Is plastertzed from
micuonal neat.
Endodontic Retreatment - Dr. Nithin Mathew
Packaging unit 6 6 6 6 6 6
Color code e e e e e, e.
Size == DO num. 025 050 055 040 015 050
121 270. 2001 2002 2003 2004 2005 2006
Assortment 2000
cr features a spiraled vent through which gutta-percha is extruded as its plastertzed
rom mictionat heat.
Nill GPX". Nickel Titantum Nite! ==
e
Packaging unit 6 6 6 6 6 6
Color code . o... © »
Size == DO vi00mm 025 050 055 oo 045 050
1-21 270, 1901 1902 1003 1004 1005 1006
Assortment 1900
A laten-type nickel titanium alloy instrument for use on low speed hand pleces. CPXT™#
features a spiraled vent through which gutta-percha is extruded as I Is plastertzed from
micuonal neat.
Endodontic Retreatment - Dr. Nithin Mathew
+ NiTi Rotary instruments
+ Advantage of removing gutta-percha as well as shaping the root canals in an
under-prepared tooth, simultaneously.
+ Several studies carried out for comparing the gutta-percha removal efficacy
of rotary with the hand instrumentation, have shown both techniques to be
almost equally effective
+ The use of rotary devices in retreatment should be followed by hand
instrumentation.
Endodontic Retreatment - Dr. Nithin Mathew
+ Advantage of removing gutta-percha as well as shaping the root canals in an
under-prepared tooth, simultaneously.
+ Several studies carried out for comparing the gutta-percha removal efficacy
of rotary with the hand instrumentation, have shown both techniques to be
almost equally effective
+ The use of rotary devices in retreatment should be followed by hand
instrumentation.
Endodontic Retreatment - Dr. Nithin Mathew
+ NiTi Rotary Instruments
+ Rotary : Reach the whole working length easily
+ Plasticize through frictional heat.
+ Hand instruments : refine and complete the removal.
+ Recommended to be used at rotational speed of 3-4 times more than that for
routine cleaning and shaping.
Endodontic Retreatment - Dr. Nithin Mathew
+ Rotary : Reach the whole working length easily
+ Plasticize through frictional heat.
+ Hand instruments : refine and complete the removal.
+ Recommended to be used at rotational speed of 3-4 times more than that for
routine cleaning and shaping.
Endodontic Retreatment - Dr. Nithin Mathew
Specialized Rotary Instruments Designed for Retreatment
+ ProTaper Universal Retreatment Kit (Dentsply)
+ D1 File : 30/0.09 NiTi file (one white ring) of 16 mm : Coronal third
+ D2 File : 25/0.08 NiTi file (two white rings) of 18 mm : Middle third
+ D3 File : 20/0.07 NiTi file (three white rings) of 22 mm: Apical third
+ R-Endo (Micro-Mega)
+ Made up from a round blank
+ Cross-section is characterized by three equally spaced cutting edges.
+ Speed of 300-400 rpm along with gutta percha solvent. |
+ Series of six files named as Rm, Re, R1, R2, R3 and Rs | » | 1
> |
VERE TE
Endodontic Retreatment - Dr. Nithin Mathew
+ ProTaper Universal Retreatment Kit (Dentsply)
+ D1 File : 30/0.09 NiTi file (one white ring) of 16 mm : Coronal third
+ D2 File : 25/0.08 NiTi file (two white rings) of 18 mm : Middle third
+ D3 File : 20/0.07 NiTi file (three white rings) of 22 mm: Apical third
+ R-Endo (Micro-Mega)
+ Made up from a round blank
+ Cross-section is characterized by three equally spaced cutting edges.
+ Speed of 300-400 rpm along with gutta percha solvent. |
+ Series of six files named as Rm, Re, R1, R2, R3 and Rs | » | 1
> |
VERE TE
Endodontic Retreatment - Dr. Nithin Mathew
+ Mtwo Retreatment Kit (Sweden and Martina)
+ S-shaped cross-section
+ 2 instruments with cutting tips designed to reach the apex.
+ Mtwo R15/.05
+ Mtwo R25/.05
+ Advantage of shaping the root canal in an under-prepared tooth, simultaneously.
Endodontic Retreatment - Dr. Nithin Mathew
+ S-shaped cross-section
+ 2 instruments with cutting tips designed to reach the apex.
+ Mtwo R15/.05
+ Mtwo R25/.05
+ Advantage of shaping the root canal in an under-prepared tooth, simultaneously.
Endodontic Retreatment - Dr. Nithin Mathew
Heat Transfer Devices
+ Heat Carrier Tips
+ System B
+ Endotec
+ EndoTwinn
+ Touch'N Heat
+ DownPak
+ Heat generated on the tip : soften guttapercha mass.
+ More effective in well prepared canals.
+ Alternatively, the hand spreaders can also be used in the similar manner, however, the
amount of heat transferred to these instruments is not consistent. 63)
Endodontic Retreatment - Dr. Nithin Mathew
+ Heat Carrier Tips
+ System B
+ Endotec
+ EndoTwinn
+ Touch'N Heat
+ DownPak
+ Heat generated on the tip : soften guttapercha mass.
+ More effective in well prepared canals.
+ Alternatively, the hand spreaders can also be used in the similar manner, however, the
amount of heat transferred to these instruments is not consistent. 63)
Endodontic Retreatment - Dr. Nithin Mathew
+ Ultrasonics
+ Piezoelectic ultrasonic system, produces heat that thermo softens GP
+ It will float coronally into the pulp chamber
+ Tips available for ultrasonic
+ Condensation of GP or specialized re-treatment tips
Endodontic Retreatment - Dr. Nithin Mathew
+ Piezoelectic ultrasonic system, produces heat that thermo softens GP
+ It will float coronally into the pulp chamber
+ Tips available for ultrasonic
+ Condensation of GP or specialized re-treatment tips
Endodontic Retreatment - Dr. Nithin Mathew
+ Soft Tissue Lasers
+ The studies, conducted on effectiveness of the Nd: YAG laser for removal of gutta-
percha, have shown that it is capable of softening gutta-percha.
+ Lower settings (100 m], 15 Hz, 1.5 W)
+ Fairly clean root canals, but an incomplete elimination of gutta-percha from
dentinal walls.
+ Increased power levels (100 mJ, 20 Hz, 2 W)
+ More effective on the canal walls, cleaning them better
+ The addition of solvents have not shown any improvement in their efficiency in terms
of time required for removal of GP.
'etreatment - Dr. Nithin Mathew
+ The studies, conducted on effectiveness of the Nd: YAG laser for removal of gutta-
percha, have shown that it is capable of softening gutta-percha.
+ Lower settings (100 m], 15 Hz, 1.5 W)
+ Fairly clean root canals, but an incomplete elimination of gutta-percha from
dentinal walls.
+ Increased power levels (100 mJ, 20 Hz, 2 W)
+ More effective on the canal walls, cleaning them better
+ The addition of solvents have not shown any improvement in their efficiency in terms
of time required for removal of GP.
'etreatment - Dr. Nithin Mathew
+ Paper point and chemical removal
+ Drying solvent filled canals with paper points is known as “wicking”
+ It is always the final step of gutta percha removal.
+ Wicking action removes residual gutta percha end sealer out of fins, cul de sac and
aberrations of the root canal.
+ Wicking takes place by pulling dissolved materials from periapical to central. (66)
Endodontic Retreatment - Dr. Nithin Mathew
+ Drying solvent filled canals with paper points is known as “wicking”
+ It is always the final step of gutta percha removal.
+ Wicking action removes residual gutta percha end sealer out of fins, cul de sac and
aberrations of the root canal.
+ Wicking takes place by pulling dissolved materials from periapical to central. (66)
Endodontic Retreatment - Dr. Nithin Mathew
Carrier Based gutta percha removal
+ After careful access and complete circumferential exposure of the carrier a
suitable grasping pliers is selected and a purchase is obtained on the carrier.
+ Carrier is grasped with the pliers and extrication is attempted using fulcrum
mechanics, rather than a straight pull out of tooth.
+ If enough canal space exists, a 4 or 5 ultrasonic instrument can be used along
side carrier to produce heat and thermosoften the G.P.
Endodontic Retreatment - Dr
+ After careful access and complete circumferential exposure of the carrier a
suitable grasping pliers is selected and a purchase is obtained on the carrier.
+ Carrier is grasped with the pliers and extrication is attempted using fulcrum
mechanics, rather than a straight pull out of tooth.
+ If enough canal space exists, a 4 or 5 ultrasonic instrument can be used along
side carrier to produce heat and thermosoften the G.P.
Endodontic Retreatment - Dr
Silver Point Removal
+ Easily removed : chronic leakage greatly reduces the seal and hence
lateral retention.
+ The coronal heads of silver points are within pulp chambers and are
entombed in cements, composites or amalgam cores.
+ Initial access with high speed surgical-length cutting tools.
+ Subsequently, ultrasonic instruments may be carefully used within the pulp chamber to
brush cut away restorative materials and progressively expose the silver point.
Endodontic Retreatment - Dr
+ Easily removed : chronic leakage greatly reduces the seal and hence
lateral retention.
+ The coronal heads of silver points are within pulp chambers and are
entombed in cements, composites or amalgam cores.
+ Initial access with high speed surgical-length cutting tools.
+ Subsequently, ultrasonic instruments may be carefully used within the pulp chamber to
brush cut away restorative materials and progressively expose the silver point.
Endodontic Retreatment - Dr
+ Pliers removal
+ Stieglitz Plier used gently pull to confirm its relative tightness.
+ When grasping a silver point, rather than trying to pull it straight out of the |
canal the plier is rotated using fulcrum mechanics and levered against the
restoration or tooth structure to enhance removal efforts.
+ Indirect Ultra Sonic
+ Used when a segment of silver point is encountered below the orifice and
space is restricted.
Endodontic Retreatment - Dr. Nithin Mathew
+ Stieglitz Plier used gently pull to confirm its relative tightness.
+ When grasping a silver point, rather than trying to pull it straight out of the |
canal the plier is rotated using fulcrum mechanics and levered against the
restoration or tooth structure to enhance removal efforts.
+ Indirect Ultra Sonic
+ Used when a segment of silver point is encountered below the orifice and
space is restricted.
Endodontic Retreatment - Dr. Nithin Mathew
+ Indirect Ultra Sonic
+ Care must be used so that ultrasonic instruments are not used directly on silver points
because elemental silver is soft and rapidly erodes during mechanical manipulation.
+ Once the surrounding material is removed, ultrasonic energy then may be transmitted on a
grasping plier to synergistically enhance the retrieval efforts.
y _ Endodontic Retreatment - Dr. Nithin Mathew
+ Care must be used so that ultrasonic instruments are not used directly on silver points
because elemental silver is soft and rapidly erodes during mechanical manipulation.
+ Once the surrounding material is removed, ultrasonic energy then may be transmitted on a
grasping plier to synergistically enhance the retrieval efforts.
y _ Endodontic Retreatment - Dr. Nithin Mathew
+ Braided file technique
+ Using Hedstrom files
+ Sealer is dissolved
+ Files are negotiated as apically as possibly in two to three areas around the silver point.
+ The spaces surrounding the silver point are carefully instrumented to size 15.
+ Then small Hedstrom files are gently screwed in as far as possible
apically.
+ The flute design of Hedstrom file allows for better engagement
into the silver point.
+ Files are then twisted together and pulled out through the access.
Endodontic Retreatment - Dr. Nithin Mathew
+ Using Hedstrom files
+ Sealer is dissolved
+ Files are negotiated as apically as possibly in two to three areas around the silver point.
+ The spaces surrounding the silver point are carefully instrumented to size 15.
+ Then small Hedstrom files are gently screwed in as far as possible
apically.
+ The flute design of Hedstrom file allows for better engagement
into the silver point.
+ Files are then twisted together and pulled out through the access.
Endodontic Retreatment - Dr. Nithin Mathew
+ Caufield silver point retrievers
° When not much of the silver point exposed in the chamber, the clinician can attempt to
remove it using the Caufield silver point retrievers (Integra Miltex).
+ Instrument is a spoon with a groove in the tip that can engage the exposed end of the silver
point so it may be elevated from the canal or possibly elevated to the point where it may be
grasped by forceps.
+ Available in three sizes:
+ 25,35 and 50
Endodontic Retreatment - Dr
° When not much of the silver point exposed in the chamber, the clinician can attempt to
remove it using the Caufield silver point retrievers (Integra Miltex).
+ Instrument is a spoon with a groove in the tip that can engage the exposed end of the silver
point so it may be elevated from the canal or possibly elevated to the point where it may be
grasped by forceps.
+ Available in three sizes:
+ 25,35 and 50
Endodontic Retreatment - Dr
Paste Removal
+ When evaluating a paste case for retreatment, it is useful to clinically understand that the
coronal portion of the paste in the canal is most dense (the material is progressively less
dense moving apically).
+ Ultrasonic energy
+ Ultrasonic instruments in conjunction with the microscope, afford excellent control in
removing paste from the straight portions of a canal.
+ To remove paste apical to a canal curvature, precurved file is attached to a specially
designed adapter that mounts on and is activated by the ultrasonic hand piece.
Endodontic Retreatment - Dr. Nithin Mathew
+ When evaluating a paste case for retreatment, it is useful to clinically understand that the
coronal portion of the paste in the canal is most dense (the material is progressively less
dense moving apically).
+ Ultrasonic energy
+ Ultrasonic instruments in conjunction with the microscope, afford excellent control in
removing paste from the straight portions of a canal.
+ To remove paste apical to a canal curvature, precurved file is attached to a specially
designed adapter that mounts on and is activated by the ultrasonic hand piece.
Endodontic Retreatment - Dr. Nithin Mathew
+ Rotary instruments
+ Stainless steel 0.02 tapered hand files to negotiate through paste fillers.
+ These files can potentially create a pilot hole for safe ended, Ni Ti rotary instruments to
follow.
+ Solvents and Hand Files
+ Reagents like Endosolv ‘R’ and Endoslov ‘E’ can be helpful in chemically softening hard
paste.
+ These reagents can be placed interappointment.
(7)
Endodontic Retreatment - Dr. Nithin Mathew
+ Stainless steel 0.02 tapered hand files to negotiate through paste fillers.
+ These files can potentially create a pilot hole for safe ended, Ni Ti rotary instruments to
follow.
+ Solvents and Hand Files
+ Reagents like Endosolv ‘R’ and Endoslov ‘E’ can be helpful in chemically softening hard
paste.
+ These reagents can be placed interappointment.
(7)
Endodontic Retreatment - Dr. Nithin Mathew
+ Micro debriders
+ To precisely remove residual paste materials
+» Offset handles, 0.02 tapers with 16mm of efficient hedstrom type cutting blades.
+ Solvents and paper points
+ After paste removal, paper point wicking in the presence of specific paste solvents is
important
Endodontic Retreatment - Dr. Nithin Mathew
+ To precisely remove residual paste materials
+» Offset handles, 0.02 tapers with 16mm of efficient hedstrom type cutting blades.
+ Solvents and paper points
+ After paste removal, paper point wicking in the presence of specific paste solvents is
important
Endodontic Retreatment - Dr. Nithin Mathew
Broken Instrument Removal
+ Incidence of hand instrument separation has been reported to be
0.25% and for rotary instruments it ranges from 1.68% to 2.4%.
(Iqbal et al 2006)
+ A common cause for instrument separation is improper use.
+ Overuse and not discarding an instrument and replacing it with a new one when
needed.
Endodontic Retreatment - Dr. Nithin Mathew
+ Incidence of hand instrument separation has been reported to be
0.25% and for rotary instruments it ranges from 1.68% to 2.4%.
(Iqbal et al 2006)
+ A common cause for instrument separation is improper use.
+ Overuse and not discarding an instrument and replacing it with a new one when
needed.
Endodontic Retreatment - Dr. Nithin Mathew
List of guidelines for when to discard and replace instruments :
1. Flaws, such as shiny areas or unwinding, are detected on the flutes
2. Excessive use has caused instrument bending or crimping
+ NiTi instruments : tend to fracture without warning
+ Constant monitoring of usage is critical
Excessive bending or precurving has been necessary
Accidental bending occurs during file use.
Corrosion is noted on the instrument.
ey fen ES
Compacting instruments have defective tips or have been excessively heated.
Endodontic Retreatment - Dr. Nithin Mathew
1. Flaws, such as shiny areas or unwinding, are detected on the flutes
2. Excessive use has caused instrument bending or crimping
+ NiTi instruments : tend to fracture without warning
+ Constant monitoring of usage is critical
Excessive bending or precurving has been necessary
Accidental bending occurs during file use.
Corrosion is noted on the instrument.
ey fen ES
Compacting instruments have defective tips or have been excessively heated.
Endodontic Retreatment - Dr. Nithin Mathew
Factors influencing broken instrument removal:
Cross sectional diameter of the canal
Length of the canal
Root morphology - thickness of dentin and the depth of external concavities.
m DS WS
Curvature ofthe canal
+ Straight portion of canal : removed usually.
+ Around canal curvature : removal is possible if the access if established to its most
coronal extent.
+ Apical to curvature : removal may not be possible.
5. Type of material that obstructs the canal
+ SS files do not fracture during removal
+ NiTi breaks again because of heat build up caused by ultrasonic devices.
Endodontic Retreatment - Dr. Nithin Mathew
Cross sectional diameter of the canal
Length of the canal
Root morphology - thickness of dentin and the depth of external concavities.
m DS WS
Curvature ofthe canal
+ Straight portion of canal : removed usually.
+ Around canal curvature : removal is possible if the access if established to its most
coronal extent.
+ Apical to curvature : removal may not be possible.
5. Type of material that obstructs the canal
+ SS files do not fracture during removal
+ NiTi breaks again because of heat build up caused by ultrasonic devices.
Endodontic Retreatment - Dr. Nithin Mathew
Technique for broken instruments removal
+ Steps:
1. Coronal access
+ Done with high speed, friction grip surgical length burs
2. Radicular access
+ Hand files, and GG drills used
+ GG drills maximize visibility coronal to the obstruction
3. Create staging platform
+ Modified GG is used.
+ Cutting the bud of GG perpendicular to its long axis at its
maximum C-S diameter.
+ This creates a small staging platform that facilitates the introduction
of ultrasonic instruments.
Endodontic Retreatment - Dr. Nithin Mathew
+ Steps:
1. Coronal access
+ Done with high speed, friction grip surgical length burs
2. Radicular access
+ Hand files, and GG drills used
+ GG drills maximize visibility coronal to the obstruction
3. Create staging platform
+ Modified GG is used.
+ Cutting the bud of GG perpendicular to its long axis at its
maximum C-S diameter.
+ This creates a small staging platform that facilitates the introduction
of ultrasonic instruments.
Endodontic Retreatment - Dr. Nithin Mathew
+ Ultrasonic instrument moved lightly in a CCW direction around the obstruction
+ This will remove the dentin and trephines around the obstruction
+ Gently, wedging the energized tip between the file and canal wall will remove the
instrument
low power settings
|
Endodontic Retreatment - Dr. Nithin Mathew
+ This will remove the dentin and trephines around the obstruction
+ Gently, wedging the energized tip between the file and canal wall will remove the
instrument
low power settings
|
Endodontic Retreatment - Dr. Nithin Mathew
MICROTUBE DEVICES
+ Instrument Retrieval System (IRS)
+ Small staging platform : Further reduced by ultrasonics until enough of the separated
instrument is exposed to retrieve.
+ Microtube is inserted into the canal and the long part of its beveled end is oriented to the
outer wall of the canal to scoop up the head of the broken instrument.
Endodontic Retreatment - Dr. Nithin Mathew
+ Instrument Retrieval System (IRS)
+ Small staging platform : Further reduced by ultrasonics until enough of the separated
instrument is exposed to retrieve.
+ Microtube is inserted into the canal and the long part of its beveled end is oriented to the
outer wall of the canal to scoop up the head of the broken instrument.
Endodontic Retreatment - Dr. Nithin Mathew
+ The insert wedge is placed through open end of microtube and passed down its internal
lumen until it contacts the broken obstruction.
+ The broken instrument is secured by turning the insert wedges handle screw in a clockwise
rotation.
Endodontic Retreatment - Dr Mathew
lumen until it contacts the broken obstruction.
+ The broken instrument is secured by turning the insert wedges handle screw in a clockwise
rotation.
Endodontic Retreatment - Dr Mathew
+ Wire Loop & Tube Removal Method :
+ 25-gauge dental injection needle
+ 0.14-mm-diameter steel ligature wire.
+ Needle is cut to remove the beveled end
+ Both ends of the wire are then passed through the needle from the
injection end until they slide out of the hub end, creating a wire loop
+ Once the loop has passed around the object to be retrieved, a small
hemostat is used to pull the wire loop up and tighten it around the
obstruction
+ Complete assembly is withdrawn from the canal.
Endodontic Retreatment - Dr. Nithin Mathew
+ 25-gauge dental injection needle
+ 0.14-mm-diameter steel ligature wire.
+ Needle is cut to remove the beveled end
+ Both ends of the wire are then passed through the needle from the
injection end until they slide out of the hub end, creating a wire loop
+ Once the loop has passed around the object to be retrieved, a small
hemostat is used to pull the wire loop up and tighten it around the
obstruction
+ Complete assembly is withdrawn from the canal.
Endodontic Retreatment - Dr. Nithin Mathew
+ Other Methods:
+ Endo Extractor (Brasseler USA)
+ Masserann Kit (Medidenta International)
+ Extractor System (Roydent)
+ Separated Instrument Retrieval System (SIRS)
Endodontic Retreatment - Dr. Nithin Mathew
+ Endo Extractor (Brasseler USA)
+ Masserann Kit (Medidenta International)
+ Extractor System (Roydent)
+ Separated Instrument Retrieval System (SIRS)
Endodontic Retreatment - Dr. Nithin Mathew
+ Specifically for use with
+ Cancellier instrument (Sybron Endo)
+ Mounce extractor (Sybron Endo)
Endodontic Retreatment - Dr. Nithin Mathew
+ Cancellier instrument (Sybron Endo)
+ Mounce extractor (Sybron Endo)
Endodontic Retreatment - Dr. Nithin Mathew
Management of Canal Impediments
+ Iatrogenic mishaps resulting from
+ Vigorous instrumentation short of the appropriate working length
+ Failure to confirm apical patency regularly during instrumentation.
+ Includes:
+ Blocked canals
+ Ledge Formation
Endodontic Retreatment - Dr. Nithin Mathew
+ Iatrogenic mishaps resulting from
+ Vigorous instrumentation short of the appropriate working length
+ Failure to confirm apical patency regularly during instrumentation.
+ Includes:
+ Blocked canals
+ Ledge Formation
Endodontic Retreatment - Dr. Nithin Mathew
Managing Blocked canals
+ Well-angulated radiographs
+ Coronal portion of the canal should be enlarged
+ To enhance tactile sensation
+ Remove cervical and middle third obstructions in the canal space
+ Canal should be flooded with irrigant, and instrumentation to the level of the
impediment should be accomplished using non-end-cutting instruments
+ Precurved #8 or #10 file used in pecking motion
+ Determine if there are any “sticky” spots that could be the entrance to a
blocked canal.
Endodontic Retreatment - Dr. Nithin Mathew
+ Well-angulated radiographs
+ Coronal portion of the canal should be enlarged
+ To enhance tactile sensation
+ Remove cervical and middle third obstructions in the canal space
+ Canal should be flooded with irrigant, and instrumentation to the level of the
impediment should be accomplished using non-end-cutting instruments
+ Precurved #8 or #10 file used in pecking motion
+ Determine if there are any “sticky” spots that could be the entrance to a
blocked canal.
Endodontic Retreatment - Dr. Nithin Mathew
+ Directional rubber stop should be used
+ Very short amplitude, light pecking strokes to be used
+ Short amplitudes - ensure safety, carry irrigant deeper, and
increase the possibility of canal negotiation
+ File's handle whose tip is engaged, should never be excessively rotated.
+ Frequent evacuation of the irrigant and using a lubricant, such as RC
prep.
+ Risk of deviating from the original canal path, creating a ledge, and
ultimately a false canal leading to zip perforation.
+ Working radiograph taken when some apical progress made
Endodontic Retreatment - Dr. Nithin Mathew
+ Very short amplitude, light pecking strokes to be used
+ Short amplitudes - ensure safety, carry irrigant deeper, and
increase the possibility of canal negotiation
+ File's handle whose tip is engaged, should never be excessively rotated.
+ Frequent evacuation of the irrigant and using a lubricant, such as RC
prep.
+ Risk of deviating from the original canal path, creating a ledge, and
ultimately a false canal leading to zip perforation.
+ Working radiograph taken when some apical progress made
Endodontic Retreatment - Dr. Nithin Mathew
* Occasionally, clinical situations arise where the aforementioned
techniques have been carefully attempted, but either the file is not
progressing apically or is not maintaining the true pathway of the canal.
+ If the tooth is asymptomatic and symptoms are not masked by a
pharmaceutical agent, and if the periodontium is healthy and there are
no lesions of endodontic origin, then the preparation may be finished to
the level of the obstruction and obturated.
Endodontic Retreatment - Dr. Nithin Mathew
techniques have been carefully attempted, but either the file is not
progressing apically or is not maintaining the true pathway of the canal.
+ If the tooth is asymptomatic and symptoms are not masked by a
pharmaceutical agent, and if the periodontium is healthy and there are
no lesions of endodontic origin, then the preparation may be finished to
the level of the obstruction and obturated.
Endodontic Retreatment - Dr. Nithin Mathew
Ledge Formation
+ An artificially created irregularity on the surface of the root canal wall that prevents the
placement of instruments to the apex of an otherwise patent canal.
+ A deviation from the original canal curvature without communication with the PDL,
resulting in a procedural error is termed ledge formation or ledging.
(JOE, 33, 2007)
Endodontic Retreatment - Dr. Nithin Mathew
+ An artificially created irregularity on the surface of the root canal wall that prevents the
placement of instruments to the apex of an otherwise patent canal.
+ A deviation from the original canal curvature without communication with the PDL,
resulting in a procedural error is termed ledge formation or ledging.
(JOE, 33, 2007)
Endodontic Retreatment - Dr. Nithin Mathew
Recognition of a Ledge :
+ Root canal instrument can no longer be inserted into the canal to full
working length.
+ Loss of tactile sensation of the tip of the instrument binding in the lumen.
+ Instrument point hitting against a solid wall
+ Radiograph with instrument in place.
Endodontic Retreatment - Dr. Nithin Mathew
+ Root canal instrument can no longer be inserted into the canal to full
working length.
+ Loss of tactile sensation of the tip of the instrument binding in the lumen.
+ Instrument point hitting against a solid wall
+ Radiograph with instrument in place.
Endodontic Retreatment - Dr. Nithin Mathew
Management:
Locating the ledge
+ Irrigate, smaller instruments are preferred.
+ No. 10 or 15 with a distal curve at the tip can be used
+ Pointed towards the wall opposite to the ledge
+ “Tear shaped” silicone stops can be used.
+ Watch-winding motion
+ If resistance is felt, retract slightly, rotate and advance again, until it
bypasses and reach apically.
+ Confirmed with a radiograph
+ Ifledge cannot be bypassed, then clean, shape and obturate till obstruction.
Endodontic Retreatment - Dr. Nithin Mathew
Locating the ledge
+ Irrigate, smaller instruments are preferred.
+ No. 10 or 15 with a distal curve at the tip can be used
+ Pointed towards the wall opposite to the ledge
+ “Tear shaped” silicone stops can be used.
+ Watch-winding motion
+ If resistance is felt, retract slightly, rotate and advance again, until it
bypasses and reach apically.
+ Confirmed with a radiograph
+ Ifledge cannot be bypassed, then clean, shape and obturate till obstruction.
Endodontic Retreatment - Dr. Nithin Mathew
Prevention of Ledge :
+ Proper examination of the diagnostic radiographs.
+ Awareness of canal morphology
+ Frequent recapitulation and irrigation
+ Precurving the instrument and not forcing it.
+ Using instruments with not cutting tip
+ Using NiTi files in case of curved canals
+ Modified instruments:
+ FlexR files
+ Safety Hedstrom files
+ Flexofile
Endodontic Retreatment - Dr. Nithin Mathew
+ Proper examination of the diagnostic radiographs.
+ Awareness of canal morphology
+ Frequent recapitulation and irrigation
+ Precurving the instrument and not forcing it.
+ Using instruments with not cutting tip
+ Using NiTi files in case of curved canals
+ Modified instruments:
+ FlexR files
+ Safety Hedstrom files
+ Flexofile
Endodontic Retreatment - Dr. Nithin Mathew
Endodontic Perforation
+ Perforations in all locations can be caused by 2 main errors:
1. Creating a ledge in the canal wall during initial preparation and perforating through
the side of the root at the point of obstructions / root curvature.
2. Using too large or too long an instrument and either perforating directly through the
apical foramen or wearing a hole in the lateral surface of the root by over
instrumentation.
Endodontic Retreatment - Dr. Nithin Mathew
+ Perforations in all locations can be caused by 2 main errors:
1. Creating a ledge in the canal wall during initial preparation and perforating through
the side of the root at the point of obstructions / root curvature.
2. Using too large or too long an instrument and either perforating directly through the
apical foramen or wearing a hole in the lateral surface of the root by over
instrumentation.
Endodontic Retreatment - Dr. Nithin Mathew
+ Level:
2
3.
4,
Endodontic Retreatment - Dr. Nil
Factors influencing repair
Considerations influencing perforation repair:
il,
Level
Location
Extend of perforation
Potential for successful management
+ Coronal / furcation perforation : threaten sulcular epithelium
+ In general, more apical the perforation, more favourable the prognosis
Mathew
2
3.
4,
Endodontic Retreatment - Dr. Nil
Factors influencing repair
Considerations influencing perforation repair:
il,
Level
Location
Extend of perforation
Potential for successful management
+ Coronal / furcation perforation : threaten sulcular epithelium
+ In general, more apical the perforation, more favourable the prognosis
Mathew
+ Location:
+ Can occur circumferentially on the buccal, lingual, mesial and distal aspects of roots.
+ Location of the perforation is not so important when non-surgical treatment is
selected.
+ Position is critical and may preclude surgical access if this approach is considered.
+ Extend € Size of Perforation:
+ Size greatly affects the clinician's ability to establish a hermetic seal.
+ The area of a circular shaped perforation can be mathematically described as 7tr2.
+ Therefore doubling the perforation size with any bur or instrument increases the
surface area to seal four-fold.
Endodontic Retreatment - Dr. Nithin Mathew
+ Can occur circumferentially on the buccal, lingual, mesial and distal aspects of roots.
+ Location of the perforation is not so important when non-surgical treatment is
selected.
+ Position is critical and may preclude surgical access if this approach is considered.
+ Extend € Size of Perforation:
+ Size greatly affects the clinician's ability to establish a hermetic seal.
+ The area of a circular shaped perforation can be mathematically described as 7tr2.
+ Therefore doubling the perforation size with any bur or instrument increases the
surface area to seal four-fold.
Endodontic Retreatment - Dr. Nithin Mathew
+ Time:
+ Regardless of the cause, a perforation should be repaired as soon as possible to
discourage further loss of attachment and prevent sulcular breakdown.
+ Esthetics:
+ Perforations in the anterior region can definitely impact esthetics.
* Tooth colored restoratives are chosen and selected from the best materials
currently available in adhesive dentistry.
Endodontic Retreatment - Dr. Nithin Mathew
+ Regardless of the cause, a perforation should be repaired as soon as possible to
discourage further loss of attachment and prevent sulcular breakdown.
+ Esthetics:
+ Perforations in the anterior region can definitely impact esthetics.
* Tooth colored restoratives are chosen and selected from the best materials
currently available in adhesive dentistry.
Endodontic Retreatment - Dr. Nithin Mathew
+ Periodontal condition :
+ If the attachment apparatus is intact without pocketing, timing is critical and the
treatment is ideally directed toward non-surgically repairing the defect.
+ Decision should be made for periodontal breakdown teeth, to go for surgical or non-
surgical or both together.
+ Longstanding defect with periodontal lesion: surgery with guided tissue regeneration
+ Most cases, nonsurgical retreatment and internal perforation repair prior to surgery will
be beneficial to the treatment outcome.
Endodontic Retreatment - Dr. Nithin Mathew
+ If the attachment apparatus is intact without pocketing, timing is critical and the
treatment is ideally directed toward non-surgically repairing the defect.
+ Decision should be made for periodontal breakdown teeth, to go for surgical or non-
surgical or both together.
+ Longstanding defect with periodontal lesion: surgery with guided tissue regeneration
+ Most cases, nonsurgical retreatment and internal perforation repair prior to surgery will
be beneficial to the treatment outcome.
Endodontic Retreatment - Dr. Nithin Mathew
Management
+ Difficulty of the repair : Level of perforation
+ Furcal floor of a multirooted tooth or in the coronal one third of a straight canal (access)
+ Considered to be easily accessible
+ Middle one third (strip or post perforations) : Difficulty increases
+ Apical one third (instrumentation errors)
+ Predictable repair
+ Frequently, apical surgery will be needed.
Endodontic Retreatment - Dr. Nithin Mathew
+ Difficulty of the repair : Level of perforation
+ Furcal floor of a multirooted tooth or in the coronal one third of a straight canal (access)
+ Considered to be easily accessible
+ Middle one third (strip or post perforations) : Difficulty increases
+ Apical one third (instrumentation errors)
+ Predictable repair
+ Frequently, apical surgery will be needed.
Endodontic Retreatment - Dr. Nithin Mathew
Barrier Materials For Perforation Repair
+ Barriers help produce a “dry field” and also provide an internal matrix or “back stop” against
which to condense restorative materials.
+ Absorbable
+ Collagen materials (colla cote)
+ Calcium sulfate (cap set)
+ Non-Absorbable
+ MTA
+ Other restoratives (amalgam, super EBA resin cement, composite restoratives, calcium
phosphate cement) (100)
Endodontic Retreatment - Dr. Nithin Mathew
+ Barriers help produce a “dry field” and also provide an internal matrix or “back stop” against
which to condense restorative materials.
+ Absorbable
+ Collagen materials (colla cote)
+ Calcium sulfate (cap set)
+ Non-Absorbable
+ MTA
+ Other restoratives (amalgam, super EBA resin cement, composite restoratives, calcium
phosphate cement) (100)
Endodontic Retreatment - Dr. Nithin Mathew
Management of Coronal Third
+ Hemostatics to control bleeding.
+ Small area : sealed from inside the tooth
+ Large area : seal from inside, then surgical repair
+ Where esthetics is a concern, a calcium sulfate barrier along with composite restoration
is generally used.
+ Super EBA have been used when esthetics not an issue.
+ Presently MTA is restorative of choice because of its many desirable attributes.
Endodontic Retreatment - Dr. Nil
Mathew
+ Hemostatics to control bleeding.
+ Small area : sealed from inside the tooth
+ Large area : seal from inside, then surgical repair
+ Where esthetics is a concern, a calcium sulfate barrier along with composite restoration
is generally used.
+ Super EBA have been used when esthetics not an issue.
+ Presently MTA is restorative of choice because of its many desirable attributes.
Endodontic Retreatment - Dr. Nil
Mathew
Management of Middle Third
+ By nature of occurrence, these defects are ovoid in shape and typically
represent relatively large surface area to seal.
+ Access to midroot perforation is most often difficult, and repair is not
predictable.
+ Successful repair depends upon the adequacy of the seal established by
the repair material.
+ The repair should be immediate, to protect the perforated site from
saliva and other contaminants.
+ Barrier material of choice is MTA.
Endodontic Retreatment - Dr. Nithin Mathew
+ By nature of occurrence, these defects are ovoid in shape and typically
represent relatively large surface area to seal.
+ Access to midroot perforation is most often difficult, and repair is not
predictable.
+ Successful repair depends upon the adequacy of the seal established by
the repair material.
+ The repair should be immediate, to protect the perforated site from
saliva and other contaminants.
+ Barrier material of choice is MTA.
Endodontic Retreatment - Dr. Nithin Mathew
Management of Apical Third
+ Overinstumentation :
+ Re-establish the WL and enlarge with larger instrument.
+ Apical barrier: Ca(OH),, MTA, Dentin Chips, Hydroxyapatite
+ Apical Perforation :
+ Negotiate
+ Perforation site as the new apical opening and obturation is done to seal of the
foramen
+ Surgery is necessary, if a lesion present apically
Endodontic Retreatment - Dr. Nithin Mathew
+ Overinstumentation :
+ Re-establish the WL and enlarge with larger instrument.
+ Apical barrier: Ca(OH),, MTA, Dentin Chips, Hydroxyapatite
+ Apical Perforation :
+ Negotiate
+ Perforation site as the new apical opening and obturation is done to seal of the
foramen
+ Surgery is necessary, if a lesion present apically
Endodontic Retreatment - Dr. Nithin Mathew
Management of Apical Third
+ Surgical Approach:
+ A combined intracoronal and surgical approach involves repairing the defect
intracoronally, then reflecting a surgical flap to remove the inevitable
overextension of the repair material from the periodontal space.
+ Incase of failing furcation repairs,
+ Bicuspidation
+ Hemi-Section
+ Intentional Replantation can be considered as treatment options.
(104)
Endodontic Retreatment - Dr. Nithin Mathew
+ Surgical Approach:
+ A combined intracoronal and surgical approach involves repairing the defect
intracoronally, then reflecting a surgical flap to remove the inevitable
overextension of the repair material from the periodontal space.
+ Incase of failing furcation repairs,
+ Bicuspidation
+ Hemi-Section
+ Intentional Replantation can be considered as treatment options.
(104)
Endodontic Retreatment - Dr. Nithin Mathew
Heat generation during treatment procedures
+ Several procedures in endodontic therapy that generate heat
+ Greatest risk with Non-surgical retreatment
+ Use of heat to soften canal filling materials
+ Use of ultrasonics to dislodge posts and separated instruments
+ Can potentially generate enough heat to raise the temperature of the external root surface by
10° Cor more.
+ Temperature elevations of the periodontal ligament in excess of 10° C can cause damage to
the attachment apparatus.
(Eriksson et al 1983, Saunders et al 1989,1990) los)
Endodontic Retreatment - Dr. Nithin Mathew
+ Several procedures in endodontic therapy that generate heat
+ Greatest risk with Non-surgical retreatment
+ Use of heat to soften canal filling materials
+ Use of ultrasonics to dislodge posts and separated instruments
+ Can potentially generate enough heat to raise the temperature of the external root surface by
10° Cor more.
+ Temperature elevations of the periodontal ligament in excess of 10° C can cause damage to
the attachment apparatus.
(Eriksson et al 1983, Saunders et al 1989,1990) los)
Endodontic Retreatment - Dr. Nithin Mathew
+ Accepted that the heat-induced damage to periradicular tissues
during the usage of ultrasound energy for post removal is Time
Dependent.
+ Study has showed that ultrasonic vibration for post removal
without coolant can cause root surface temperature increases
approaching 10° C in as little as 15 seconds.
(Dominici et al 2005)
Endodontic Retreatment - Dr. Nithin Mathew
during the usage of ultrasound energy for post removal is Time
Dependent.
+ Study has showed that ultrasonic vibration for post removal
without coolant can cause root surface temperature increases
approaching 10° C in as little as 15 seconds.
(Dominici et al 2005)
Endodontic Retreatment - Dr. Nithin Mathew
Recommendations for the use of ultrasound energy during the removal of canal obstructions :
+ Use ultrasonic tips with water ports whenever possible
+ If ultrasound device does not have tips with waterports, have your assistant use a continuous
water/saline irrigation during usage.
+ Take frequent breaks to let the tooth cool down.
+ Avoid using the ultrasound on the high power setting.
(107)
Endodontic Retreatment - Dr. Nithin Mathew
+ Use ultrasonic tips with water ports whenever possible
+ If ultrasound device does not have tips with waterports, have your assistant use a continuous
water/saline irrigation during usage.
+ Take frequent breaks to let the tooth cool down.
+ Avoid using the ultrasound on the high power setting.
(107)
Endodontic Retreatment - Dr. Nithin Mathew
Conclusion
+ Posttreatment endodontic disease does not preclude saving the involved tooth.
+ In fact, the majority of these teeth can be returned to health and long-term function by
current retreatment procedures.
+ In most instances the retreatment option provides the greatest advantage to the patient
because there is no replacement that functions as well as a natural tooth.
+ Armed with the information in the preceding section, appropriate armamentaria, and the
desire to do what is best for the patient, the clinician will provide the foundation for long-
term restorative success. (108)
y _ Endodontic Retreatment - Dr. Nithin Mathew
+ Posttreatment endodontic disease does not preclude saving the involved tooth.
+ In fact, the majority of these teeth can be returned to health and long-term function by
current retreatment procedures.
+ In most instances the retreatment option provides the greatest advantage to the patient
because there is no replacement that functions as well as a natural tooth.
+ Armed with the information in the preceding section, appropriate armamentaria, and the
desire to do what is best for the patient, the clinician will provide the foundation for long-
term restorative success. (108)
y _ Endodontic Retreatment - Dr. Nithin Mathew
References
+ Pathways of the Pulp - Cohen
+ Textbook of Endodontics - Ingle
+ Endodontic practice - Grossman
(109)
Endodontic Retreatment - Dr. Nithin Mathew
+ Pathways of the Pulp - Cohen
+ Textbook of Endodontics - Ingle
+ Endodontic practice - Grossman
(109)
Endodontic Retreatment - Dr. Nithin Mathew
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