IRRIGATION uses and techniques , advantages and disadvantages

Irrigation uses n technologies

1. IRRIGATION Presented by: Dr. Srishti Chaturvedi MDS 2 nd year

2. Topics to Be Covered Introduction History Objectives of irrigation Ideal requirements of irrigating solutions Factors modifying the activity of irrigating solutions Hydrodynamics of irrigation Classification of irrigating solution Systems of irrigation Canal preparation for irrigation Conclusion

3. Introduction: Irrigation is defined as “ to wash out a body cavity or wound with water or medicated fluid” and aspiration as “ the process of removing fluids or gases from the body with suction device.” (by Cohen, 12 th edition) Disinfectant, meanwhile, is defined as “ an agent that destroys or inhibits the activity of microorganisms that cause disease”.

4. History The concept of the germ theory of disease combined with the development of dentistry during the latter half of the 19th century had a direct effect on the practice of endodontics . The significance of root canal irrigation to endodontics strengthened in the period between 1859 when Taft recommended frequent syringing of the root canal to remove "irritants“, until the mid-1940s when endodontics became a special field within dentistry and the American Endodontic Society was established. While it was widely assumed that by wiping the root canal with disinfectants sterilization would be achieved, many of the principles associated with cleaning the root canal published during this period, in particular by Willoughby Dayton Miller in the 1890s and Louis Grossman in the 1940s, remain equally relevant in the 21st century.

5. OBJECTIVES OF IRRIGATION: Flush out debris Lubricate the canal Dissolve organic and inorganic tissue Prevent the formation of smear layer during instrumentation or dissolve it once it has formed Detach the disrupt biofilms

6. Ideal requirements …. Broad spectrum antimicrobial action Aid in debridement of root canal system Ability to dissolve necrotic tissue or debris Low toxicity level Good lubricant Low surface tension to flow into inaccessible area Ability to sterilize the canal It should be able to prevent formation of smear layer during instrumentation or dissolve the latter once it is formed

7. Ideal requirements …. 9. It should inactivate endotoxin . 10. Ease of use, convenience, adequate shelf life and ease of storage . 11. When irrigants come in contact with vital tissue, they should be systemically non-toxic, non cancerous, non-caustic to periodontal tissue and have little potential to cause an anaphylactic reaction. 12. Relatively inexpensive

8. Factors Modifying the Activity of Irrigating Solutions Concentration Contact Presence of organic tissue Quantity Temperature

9. Hydrodynamics of irrigation: Irrigation dynamics refers to how irrigants flow, penetrate, and readily exchange within the root canal walls as well as the forces produced by them. Hence, in endodontic disinfection, the process of delivery is as essential as the antibacterial characteristics of the irrigants. The effectiveness of root canal irrigation in terms of debris removal and eradication of bacteria depends on several factors that can be controlled by the operator:- Penetration depth of the needle Diameter of the root canal Inner and outer diameter of the needle Irrigation pressure Viscosity of the irrigant

10. 6. Velocity of the irrigant at the needle tip 7. Type and orientation of the bevel. The size and the length of the irrigation needle- to root canal dimension-are of outmost importance for the effectiveness of irrigation The external needle diameter is of relevance for the depth of introduction into the root canal and rigidity of the needle body, as essential consideration for irrigation of curved canals. Common 27 gauge injection needles have an external diameter of 0.42mm, but smaller stainless steel irrigation tips with external diameters of 0.32mm (30 gauge), and even 31 gauge or 0.26mm ( Navitip , ultradent , south jordan , UT, USA) are available. The stropko flexi tip (30 gauge) needle is fabricated from nickel titanium to improve penetration into curved canals. More recently, a flexible plastic irrigation tip was introduced ( Trunatomy , Dentsply sirona ).

11. Apical pressure is the force applied perpendicular to the apical wall surface. Internal syringe diameter determines the pressure necessary for moving the syringe plunger. Speed of the plunger determines the velocity with which irrigant extruded. Fine needles require more pressure onto the plunger and extrude the irrigant with the higher velocity than larger needle sizes, which extrude significantly greater amounts of irrigants but for safety reasons cannot be introduced as deeply. To improve the safety of irrigation and prevent extrusion of the irrigant through the apical foramen, some needle types release the solution via lateral openings and have a closed, safe-ended tip. Side vented and double side vented needles led to maximum shear stress concentration on the wall facing the outlet.

12. Non chemical irrigating solutions Tap Water One of the earliest irrigating solutions used for flushing of the root canal. Hot water A steam of hot water 140 -176 F discharged from the insulated syringe (Grossman) Physiologic Saline Normal saline solution may be the best irrigant to use because it cause less apical tissue damage than other irrigants . Advantages: Physical flushing action of irrigation to remove debris Bio compatibility Disadvantages : It has none of the properties of tissue solvent Poor anti-bacterial effect Incapable of dissolution of necrotic tissue

13. CHEMICALLY ACTIVE SOLUTIONS SODIUM HYPOCHORIDE Introduction It has been the most common endodontic irrigant for many years. In the First World War, the chemists Henry Drysdale Dakin and Surgeon Alexis Carrel used buffered 0.5% sodium hypochlorite solution to irrigate infected wounds. Types Unbuffered Buffered ( with potassium Bicarbonate k/n as Diakin’s sol )

14. CHEMICALLY ACTIVE SOLUTIONS SODIUM HYPOCHORIDE Concentration 0.5 to 5.25 % Mechanism Saponification reaction Amino acid neutralization reaction Chloramination reaction

15. NaOcl acts as an organic and fat solvent that degrades fatty acids and transforms them into fatty acid salts (soap) and glycerol (alcohol), reducing the surface tension of remaining solution Sodium hypochlorite neutralizes amino acids and forming water and salt. With the exit of hydroxyl ions, the pH is reduced NaOCl also acts as solvent, releasing chlorine that combine with protein amino groups (NH) to forms chloramines. Chloramines impede cell metabolism; chlorine is a strong oxidant and inhibits essential bacterial enzymes by irreversible oxidation of sulphydryl group. Saponification : Neutralization reaction: Solvent action:

16. CHEMICALLY ACTIVE SOLUTIONS SODIUM HYPOCHORIDE Methods by which we can increase the efficacy of sodium hypochlorite Time Heat Specialized irrigating syringes Ultrasonic activation of NaOCl

17. CHEMICALLY ACTIVE SOLUTIONS SODIUM HYPOCHORIDE Drawbacks…. Decreased surface tension Increased dentin permeability Toxic to the periradicular tissues Free Radicle formation Unpleasant taste Lack of ability to remove smear layer

18. CHEMICALLY ACTIVE SOLUTIONS CHLORHEXIDINE Introduction Chlorhexidine in the form of a salt ( gluconate acetate hydrochlorate ) has been used since 1950 in different conc. as an oral antiseptic in the form of a mouthwash. Types Water based solution Gel ( with Natrosol ) Liquid mixture with surface active agents

19. CHEMICALLY ACTIVE SOLUTIONS CHLORHEXIDINE Concentration 0.5 to 2% Mechanism The antimicrobial mechanism of chlorhexidine is related to its cationic bisbiquanide molecular structure. The cationic molecule is absorbed to negatively charged inner cell membrane and cause leakage of intercellular components.

20. CHEMICALLY ACTIVE SOLUTIONS CHLORHEXIDINE

21. CHEMICALLY ACTIVE SOLUTIONS CHLORHEXIDINE Combinations CHX + Calcium hydroxide Increased efficacy CHX + H 2 o 2 Synergistic effect CHX + NaoCl Orange-Brown ppt

22. CHEMICALLY ACTIVE SOLUTIONS HYDROGEN PEROXIDE Introduction It is a biocide. Not very popular Concentration 1 – 30% ( Superoxol ) Mechanism Hydroxyl free radicles (HO) Bacterial DNA and protein

23. CHEMICALLY ACTIVE SOLUTIONS HYDROGEN PEROXIDE Mechanism It causes oxidation of bacterial sulfhydryl group of enzymes and thus interferes with bacterial metabolism. The rapid release of nascent oxygen on contact with organic tissues results in effervescence of bubbling action which is thought to aid in mechanical debridement by dislodging particles of necrotic tissue and dentinal debris and floating them to the surface.

24. CHEMICALLY ACTIVE SOLUTIONS HYDROGEN PEROXIDE Combinations H 2 O 2 + CHX Strong synergism H 2 O 2 ( 3%) + NaOCl ( 5.25 %) Beneficial H 2 O 2 = bubbles out debris into pulp chamber through least resistant orifice. NaOCl = Tissue dissolving property Both = Bleaching

25. CHEMICALLY ACTIVE SOLUTIONS GLY-OXIDE   It is a 10% solution of carbamide peroxide in anhyderous glycerol. Action It provides lubrication without softening dentin. It has antimicrobial activity more than 3% H 2 O 2 . It produces transient energetic effervescence that mechanically forces debris and microorganism out of canal when used with NaOCl , alternatively. Limitation It does not remove smear layer.

26. CHEMICALLY ACTIVE SOLUTIONS EDTA ( Ethylene Diamine Tetra acetic Acid) Introduction Was introduced in Endodontics by Nygaard and Ostby in 1957 . Structure C 2 H 3 O 2 C 2 H 3 O 2 N - CH 2 – CH 2 – N C 2 H 3 O 2 C 2 H 3 O 2

27. CHEMICALLY ACTIVE SOLUTIONS EDTA ( Ethylene Diamine Tetra acetic Acid ) Composition Disodium salt of EDTA 17.00 g Water 100.00 mL 5 M sodium hydroxide 9.25 mL Concentration 17 % ( pH-7)

28. CHEMICALLY ACTIVE SOLUTIONS EDTA ( Ethylene Diamine Tetra acetic Acid ) Mechanism of action EDTA would seek the calcium metal ion in the hydroxyapatite crystals of dentin in a chelate and thereby act to demineralize dentin and enamel. The dentin thereby becomes more friable and easy to instrument. Note- The H+ ions produced during chelation of calcium present in dentin, lead to an acidic environment and EDTA is inactivated in acidic environment and therefore is self- limiting.

29. CHEMICALLY ACTIVE SOLUTIONS EDTA ( Ethylene Diamine Tetra acetic Acid ) Functions of EDTA Lubrication Emulsification Smear Layer removal Dispensed in two forms – Viscous and Aqueous. Combinations NaOCl+ EDTA complete removal of smear layer However recent reports show inactivation of Cl in NaOCl by EDTA

30. CHEMICALLY ACTIVE SOLUTIONS EDTA ( Ethylene Diamine Tetra acetic Acid) Combinations EDTA + Quantery ammonia EDTAC Smear Clear ( synbron endo) 17% EDTA + H 2 O 2 + + Centriamide + Anionic Surfactant

31. CHEMICALLY ACTIVE SOLUTIONS RC PREP Stewart in 1969 introduced another modification of EDTA called RCPREP. RCPREP is composed if EDTA and urea peroxide in base of carbo wax. It is not water soluble. When used in combination with NaoCl , its urea peroxide component reacts with NaOCl , producing bubbling action thought to loosen and float dentinal debris. principle ingredients are EDTA, urea peroxide and propylene glycol. Glycol is the lubricant that coats the instruments and facilitates their movement in open canals and those containing calcified material.

32. CHEMICALLY ACTIVE SOLUTIONS EGTA [ Ethylene gylcol bis -(beta- aminoethyl ether)-N- tetraacetic acid Recently a new chelating agent has been introduced. It is structurally quite similar to EDTA. EDTA is under evaluation to be used individually and in combination with other irrigants . EGTA removed the smear layer without inducing a corrosive action EGTA and NaOCl did not remove the superficial smear layer in the apical third and some of the tubular orifices were clogged. Thus EGTA was not found to be as effective as EDTA.

33. CHEMICALLY ACTIVE SOLUTIONS Calcinase 17% sodium edetate +sodium hydroxide as a stabilizer and purified water. REDTA 17% EDTA solution + 0.84 g Cetyl-trimethyl ammonium bromide ( Cetrimide ) + 9.25 mL 5 M sodium hydroxide and 100 mL distilled water. EDTAC and DTPAC EDTA (15%) + diethyl- triamine - penta acetic acid (DTPA) at pH 8. EDTA-T 17% EDTA + sodium lauryl ether sulfate ( Tergentol ).

34. CHEMICALLY ACTIVE SOLUTIONS CDTA 1 % solution of cyclohexane-1,2-diaminetetraacetic acid . Largal Ultra 15% EDTA + 0.75% Cetyl -tri-methyl ammonium bromide ( Cetrimide ) + sodium hydroxide. Decal 5.3 % oxyl -acetate + 4.6% ammonium oxyl -acetate + 0.06% Cetyl -tri-methyl ammonium bromide ( Cetrimide ) - pH value of 3.4 . Tubulicid Plus 1.5 g Amphoteric-2 (38%) + 0.5 g benzalkonichloride + 3 g disodium EDTA dihydrate + phosphate buffer solution + 100 g distilled water + 50% citric acid.

35. CHEMICALLY ACTIVE SOLUTIONS IKI ( Iodine potassium iodide ) Introduction Oldest disinfectant and is still actively used . It is best known for their use on skin, surface and operation field Concentration 2% Composition Iodine 2 gms KI 4 gms Water 94ml

36. CHEMICALLY ACTIVE SOLUTIONS IKI ( Iodine potassium iodide ) Storage Poor stability in aqueous solution, led to the development of … Iodophor ‘ iodine carrier’ Povidone - iodine Poloxamer - iodine Iodophors less active against spores and some yeasts than tincture iodine . Mechanism Oxidizing agent that reacts with sulfhydrl groups of bacterial enzymes, clearing the disulphide bonds.

37. CHEMICALLY ACTIVE SOLUTIONS IKI ( Iodine potassium iodide ) Advantages Rapid antiseptic action against broad range of microorganisms Low toxicity Hypoallergenicity   Disadvantage Iodine is a possible allergic reaction in some patient

38. CHEMICALLY ACTIVE SOLUTIONS SALVIZOL Introduction  NI decamethylene bis 4 aminoquinaldinium acetate is a quarternary ammonium compound with neutral pH. Action It has good bactericidal and fungicidal action. It has surface tension reducing action. It has been shown to dissolve organic matrix of dentinal tubules and thus widening the tubules. Limitation It does not remove smear layer.

39. CHEMICALLY ACTIVE SOLUTIONS HEBP Introduction Recent study identified it as a possible alternative to EDTA or citric acid as it shows no short term reactivity with sodium hypochlorite. Chemistry 1-hydroxyethylidene-1, 1-bisphosphonate . Advantages Non-toxic (commonly used systemically to treat bone diseases) Russel & Rogers 1999 HEBP is an active ingredient which could be used in combination with sodium hypochlorite irrigant without losing the action of hypochlorite.   Disadvantages Unable to inhibit formation smear layer in the apical third of the canal

40. CHEMICALLY ACTIVE SOLUTIONS RUDDLE’S SOLUTION This solution is based on the use of HYPAQUE – M, a radio- opaque, high contrast injectible dye. This dye has previously been used in several application such as arteriography , venography and ureterography in the medical field. This particular solution was introduced by an American researcher, Dr. Clifford J. Ruddle .   Composition 5% Sodium Hypochlorite Hypaque M 17% EDTA Hypaque M is a high viscous aqueous solution of two iodine salts   Advantages Solvent action ( radio-opacity similar to Gutta Percha ) because of Hypaque Penetration because the tensioactive agent decreases the surface tension besides removing the smear layer

41. ACIDS.... Tannic Acid Introduction It has been safely used in the body for more than 100 years . In 1925, Davidson recommended its use in the treatment of burns. Effect Tanizaki & Inoue also reported that it caused an increase in dentin hardness because of its inhibiting effect on calcium dissolution while the organic matter in dentin was reinforced. Constriction & obliteration of dentinal tubules has been observed & dissolution of organic matter was inhibited. Bitter et al 1989 evaluated the cleansing properties of 25% tannic acid and concluded that it removed smear layer after normal cleansing with hydrogen peroxide and sodium hypochlorite.

42. ACIDS.... Citric Acid Introduction Has been recommended as a canal irrigant because of its ability to demineralize and remove the smear layer effectively. Concentrations… 10%, 25% and 50% pH… 1.28

43. Antibiotic containing… TETRACYCLINE Tetracycline was tried as irrigant in root canal due to its antibacterial and chelating action. Tetracycline as hydrocycline hydrochloride salt has low pH (pH value 2) so it effectively removes smear layer. The tetracycline hydrochloride and doxycycline hydrochloride were tested in concentration ranging from 25 mg/ml to 100 mg/ml. The efficacy in removing smear layer was found to be more in 25 mg/ml strength solutions.

44. Antibiotic containing… DOXYCYCLINE HYDROCHLORIDE A hydroxyl derivative of tetracycline, Doxycycline hydrochloride has been tried as an irrigant . The lower concentrations of doxycycline-HCl were significantly more effective in the presence of sodium hypochlorite than when used with saline . This raises the possibility that a combination of doxycycline-HCl and sodium hypochlorite could be a more effective irrigant . Higher doses of doxycycline are toxic and inhibit fibroblast adherence and spread along a substratum. The doxycycline-HCl solution is an effective irrigant in combination with sodium hypochlorite and has potential in root canal treatment procedures. The solution is easily delivered to the root canal system and adheres to the canal wall.   Advantage The dentin surface is capable of acting as a reservoir by adsorbing and slowly releasing antibacterial levels of doxycycline into the adjacent environment for several days following topical application of this antibiotic solution.

45. Antibiotic Containing… MTAD ( Biopure , Dentsply , Tulsa, OK ) COMPOSITION AND FUCTION Tetracycline isomer Antibacterial activity Doxycycline Citric Acid Removes smear Layer resposible for low pH 2.15 Tween 80 Detergent ADVANTAGES Gentler on dentin than EDTA RECOMMENDATIONS The authors who introduced MTAD have recommended the use of 1.3% NaOCl (20 mins ) during instrumentation followed by MTAD (5 mins ).

46. Antibiotic containing… CYTOTOXITY.. Study by Zhang et al in 2003 The results showed MTAD to be less cytotoxic than eugenol , 3 percent H 2 O 2 , Ca(OH) 2 paste, 5.25 percent NaOCl , Peridex , and EDTA. TETRACLEAN ( Orga Laboratori Farmaceutici , Muggio , Italy ) Is another combination product similar or close to MTAD

47. Antibiotic containing… TITANIUM – TETRAFLUORIDE   Titanium tetra fluoride is a latest advancement in smear layer management. It does not remove the smear layer but modifies it. Titanium is a non toxic element and has a remarkable and complex binding capacity with fluoride, enamel and dentin. When TiF4 is dissolved in water; it hydrolyses to give a low pH to the solution. Despite its highly acidic pH, it produces only a partial demineralization limited to the outermost 8 – 10 µ of the root surface. This non ionized compound penetrates more easily into the hydroxyl-apatite lattice in the tooth surface. Thus titanium and fluoride uptake is increased in root surfaces.

48. Antibiotic containing… TITANIUM – TETRAFLUORIDE   Titanium tetra-fluoride is used in a 4% solution. After its application a tenacious titanium rich coating is readily formed. This coating may involve organometallic complexes; its formation favored by the rich organic matrix of the root tissues the thickness of the coating, may be as high as 1-5µ of the root canal wall, when smear layer is present. When the TiF 4 modified smear layer is treated with NaOCl and EDTA, no change was observed, indicating its stability. The modified smear layer and smear plugs in the dentinal tubules present a mechanically and chemically interlocked layer occluding all dentinal tubules permanently. Researchers suggest a possible formation of titanium dioxide coating as a alternative mode of action to organic complex formation. The modified smear may contribute adhesive forces to reduce microleakage by preventing further disintegration of the smear layer.

49. Recent Developments… OZONATED WATER Ozone is a powerful oxidizing agent. When it dissolves in water, it becomes highly unstable and rapidly decomposes through a complex series of chain reactions. As a result, hydroxyl radicals are generated. Ozone reacts with various chemical compounds in aqueous systems in 2 different and coexisting modes: Involving direct reactions of molecular ozone Free radical mediated reaction Both may be involved in destruction of bacteria by ozone. Ozonated water is powerful antimicrobial.

50. Recent Developments… OZONATED WATER Ozone in aqueous or gaseous phases has a strong oxidizing power with reliable anti-microbial effects. Ozone destroys cell walls & cytoplasmic membranes of bacteria & fungi Membrane is damaged by oxidation, its permeability increases and ozone molecules can readily enter the cell, causing microoraganism to die Stability of ozone in water is low. Gaseous ozone has no significant antibacterial effect on biofilms . Effectiveness of ozone is highest in solution.  

51. Recent Developments… OZONATED WATER Advantages Potency Ease of handing Lack of mutagenicity Rapid microbial effects Disadvantages Requires continuous flow for its action. Rapid ozone degradation on contacting organic compounds. 0.2-0.5ppm can cause headache, irritation/dryness of nose, throat, eyes. 1-10ppm over a few hours can cause congestion, oedema , haemorrhage , changes to blood and loss of vital lung capacity. 0.2ppm can cause irritation to eyes, redness, blurred vision Ozone may be linked to allergic airway disease.

52. Recent Developments… ELECTROCHEMICALLY ACTIVATED Introduction Developed by Russian Scientists at the All-Russian Institute for Medical Engineering (Moscow, Russia CIS). ECA solutions are produced from tap water and low concentration salt solutions such as saline by a special unit that houses a unique flow-through electrolytic module (FEM) ECA involves 2 processes Chemical processes Electrical process ( done without additives)  

53. Recent Developments… ELECTROCHEMICALLY ACTIVATED WATER Basis of the technology Based on the process of transferring liquids into a meta stable state via an electrochemical unipolar (anode/ cathode) action through the use of an element/ enactor (FEM). The FEM contains the anode, made from titanium and coated with ruthenium oxide, platinum and iridium, and the cathode, made from titanium coated with hydrocarbon and glass carbon. The anode (solid titanium cylinder) fits coaxially inside the cathode, a hollow cylinder. A diaphragm that separates the anode and cathode consists of ultrafiltration , electro-catalytic ceramics on a bed of zirconium, yttrium, aluminium and niobium oxide. Electrochemical treatment in the anode and cathode chambers of the diaphragm electrolyzer transforms water and low mineral solutions into a metastable state. Two types of solutions are produced. Anolyte Catholyte

54. Recent Developments… ELECTROCHEMICALLY ACTIVATED WATER Basis of the technology Anolyte is antimicrobial Anolyte has a high oxidation potential Catholyte is an alkaline solution with oxidation reduction potential. It is characterized by a pH value > 9. Main biocidal reagents: OH - , H 2 O 2 and NaOH provide a strong cleaning or detergent effect of catholyte . It dissolves necrotic tissue being safe for vital tissues ( Prilutskill an Bakhir 1997) It does not have a bad odor. It has a “soapy feel”. It acts as a detergent and is biocompatible. Acid anolyte solution may be useful for removing debris and the smear layer whilst the catholyte solution may act as a detergent and is considered to be biocompatible

55. Recent Developments… ELECTROCHEMICALLY ACTIVATED WATER Sterilox Unit: Sterilox is a commercially available unit that produces anolyte (Sterilox solution) and catholyte (sodium hydroxide pH 12.5) from a quality controlled prepackaged solution. The main active ingredient that is produced by the Sterilox generator is 85-95% hypochlorous acid. This agent is a very effective biocide but is also non-toxic, non-sensitizing, non-irritating and non-mutagenic. It may be useful as an endodontic irrigant.

56. Recent Developments… OXIDATIVE POTENTIAL WATER Developed in Japan. OPW is defined as an electrolytically obtained highly acidic water having accumulated in the anode compartment after sodium chloride added water has consumed OH - ions. It constitutes the counterpart of alkaline water forming in the cathode containing compartment after the water therein has consumed H + ions. Antimicrobial activity of OPW is characterized by –  1. It has outstanding antimicrobial activity killing viruses as well as bacteria 2. An unusually low pH of 2.7 or less 3. An oxidation reduction potentials as high as 1050 mV or more. 4. Has several activated oxygen containing antimicrobial constituents, such as HOCl and O 3- . OPW has strong antimicrobial activity, killing viruses as well as bacteria Ultrasonic irrigation with OPW was less effective is removing the smear layer than syringe irrigation

57. IRRIGATING SYSTEMS…

58. IRRIGATION… Various Available irrigating systems…. Syringe delivery Stropko irrigator Flexi Navi tips Manually activated irrigation EndoVac Negative apical pressure irrigation Safety irrigator Gentlewave system Ultrasonic and sonic irrigation Endoactivator Max i Probe LASER Activated irrigation Photo activated disinfection Actibacterial nanoparticles Heal zone Water preparations

59. Application of an irrigant into a canal using a syringe and needle allows exact placement, replenishing of existing fluid, rinsing out of larger debris particles, as well as allowing direct contact to microorganisms in areas close to the needle tip. In passive syringe irrigation, the actual exchange of irrigant is restricted to 1 to 1.5mm apical to needle tip, with fluid dynamics taking place near the needle outlet. Volume and speed of fluid flow are proportional to the cleansing efficiency inside a root canal. Excess pressure or binding of needles into canals during irrigation with no possibility of backflow of the irrigant should be avoided under all circumstances to prevent extrusion into periapical spaces IRRIGATION… Syringe delivery:

60. IRRIGATION… Max i Probe

61. IRRIGATION… Max i Probe

62. IRRIGATION… STROPKO IRRIGATOR (Vista Dental Products, Racine,WI ) INTRODUCTION Introduced by John. J Stropko ….is an adapter that connects to the air/water syringe ADVANTAGES Allows very precise delivery at a pressure of 2 and 7 psi. It aids in delivery under high power magnification.

63. IRRIGATION… KIT INCLUDES… One, Stropko Irrigator. Five, Blue-Flow tips. One, Air Regulator with Fittings .

64. IRRIGATION… Ni-Ti Flexi Tips NiTi Flexi-Tip 30 gauge Nickel Titanium Irrigating Needle tips are reportedly flexible enough to facilitate access in any canal. The tips are slotted and side vented for safe irrigation. Not only are they fully autoclavable , but they are also coated on the inside and outside to protect against the corrosive effects of sodium hypochlorite. The universal luer style design is available in 17mm and 25mm working lengths.

65. Liquid placed inside the root canal more effectively reaches crevices and mechanically untouched areas if it is agitated inside the root canal. Corono -apical movements of the irrigation needle, stirring movements with small endodontic instruments, and manual push pull movements using a fitted master gutta percha cone have been recommended. IRRIGATION… Manually activated irrigation

66. IRRIGATION… ENDOVAC ( DISCUS DENTAL) INTRODUCTION Designed by Dr G. John Schoeffel PRINCIPLE The system utilizes apical negative pressure through the offices high volume evacuation system permitting thorough irrigation with high volumes of irrigation solution.

67. IRRIGATION… COMPONENTS Hi-Vac hose assembly EndoVac Master Delivery (irrigation-suction) tip on a disposable syringe EndoVac MacroCannula on the titanium handpiece EndoVac MicroCannula in the fingerpiece and close up showing the blunt end with multiple lateral micro holes. EndoVac single use pack

68. Irrigant is delivered into the access chamber, and a very fine needle connected to the dental unit’s suction device is placed into the root canal. Excess irrigant from the access cavity is then transported apically and ultimately removed via suction. Commercially available:- ( EndoVac , Discuss dental), In a recent study, apical negative pressure mode of irrigation generated the lowest wall shear stress. Another device:- RinsEndo system ( Durr Dental, Bietigheim Bissingen , Germany). It aspirates the delivered rinsing solution into an irrigation needle that is placed close to WL and at the same time activates the needle with oscillations of 1.6 Hz amplitude. IRRIGATION… NEGATIVE APICAL PRESSURE IRRIGATION

69. The safety irrigator (Vista Dental Products) is an irrigation/evacuation system that apically delivers the irrigant under positive pressure through a thin needle containing a lateral opening and evacuates the solution through a large needle at the root canal orifice. The safety irrigation irrigator features a large coronal evacuation tube, enabling the user to irrigate and evacuate simultaneously safely. These techniques produced better cleaning efficacy than syringe irrigation (P<0.005) but significantly worse than manually dynamic activation (MDA) with tapered cone (P<0.05). IRRIGATION… Safety irrigator

70. The GentleWave system (GW) ( Sonendo Inc, Laguna Hills, CA) was introduced in the united states in 2016. The device is composed of a console, a so called procedure instrument, which is a single use tip attached to a handpiece , and a central unit that contains three individual irrigation solution containers, one waste canister, a degassing system, and a pressure generator. The system delivers an energized flow of irrigation solutions from the central unit to the procedural instrument. According to the manufacturer, the fluid stream entering the tooth creates a shear force, which in turn causes hydrodynamic cavitation . IRRIGATION… GENTLEWAVE SYSTEM

71. The implosion of micro-bubbles then creates an acoustic field of broadband frequencies, which travels through the fluid into the root canal system. The programmed irrigation regimen begin with 3% NaOCL followed by 8% EDTA, with a rinse of distilled water in between and completion. The fluid within the root canal space is continuously collected and removed from the chamber through a five point vented suction system built in the sealing lid of the procedural instrument. A sealed environment is needed between the tooth and the GW procedure instrument to allow for constant refreshing of degassed procedure fluids and simultaneous evacuation of debris.

72. PHYSICAL METHODS Ultrasonics History Richman in 1957 first introduced ultrasonics in endodontics Martin and cunningham in 1976 were first to develop the device k/n as Cavitron endodontic system. Principle Sound ( 25-30 KHz) is used to cause 3-D activation of file Mechanism Ultrasonics is an excellent means of canal debridement when used with a suitable irrigating solution. Intially the means was thought to be ‘ Cavitation ’ but later a study done by Guy’s Hospital London found it to be ‘Acoustic Streaming’

73. IRRIGATION… CAVITATION In the fluid mechanical context - Impulsive formation of cavities in a liquid through tensile forces induced by high-speed flows or flow gradients. Leighton (1994) - Acoustic cavitation can be defined as the creation of new bubbles or the expansion, contraction and/or distortion of pre-existing bubbles (so-called nuclei) in a liquid, the process being coupled to acoustic energy. According to Roy et al. (1994), two types of cavitation could occur during PUI of root canals: Stable cavitation could be defined as linear pulsation of gas-filled bodies in a low amplitude ultrasound field. Transient cavitation occurs when vapour bubbles undergo highly energetic pulsations

74. IRRIGATION… CAVITATION When the acoustic pressures are high enough, the bubbles can be initially driven to a violent collapse, radiating shock waves and generating high internal gas pressures and temperatures. The energy at the collapse point is in some cases sufficient to dissociate the gas molecules in the bubble, which recombine radiatively to produce light, a process known as sonoluminescence . Transient cavitation only occurs when the file can vibrate freely in the canal or when the file touches lightly (unintentionally) the canal wall. Increased (intentional) contact with the canal wall, as in UI, excludes transient cavitation .

75. IRRIGATION… CAVITATION The surface property of the file is important for the enhancement of cavitation (Roy et al. 1994). A smooth file with sharp edges and a square cross-section produced significantly more transient cavitation than a normal K-file. The sharp edges could have induced so-called edge cavitation. The transient cavitation was visible at the apical end and along the length of the file. When the file came in contact with the canal wall, stable cavitation was affected less than transient cavitation and was mainly seen at the midpoint of the file (Roy et al. 1994). A pre-shaped file brought into a curved canal is more likely to produce transient cavitation rather than a straight file.

76. IRRIGATION… ACOUSTIC STREAMING Walmsley (1987) - Acoustic streaming is the rapid movement of fluid in a circular or vortex-like motion around a vibrating file. Leighton (1994) - defined as the streaming which occurs near small obstacles placed within a sound field, near small sound sources, vibrating membranes or wires, which arise from the frictional forces between a boundary and medium carrying vibrations of circular frequency.

77. IRRIGATION… ACOUSTIC STREAMING 3-D file activation… ‘Eddy Motion’ i.e small, circular vigrous motion around the file. Eddying more at the tip than at the coronal end Motion of the File Sinus wave fashion maximum displacement k/n Antinode no displacement k/n node Amplitude of the file = 20-140 mm depending on the power and space around the file. The displacement amplitude is at its maximum at the tip of the file, probably causing a directional flow to the coronal part of the root canal.

78. IRRIGATION… ACOUSTIC STREAMING The intensity of the acoustic microstreaming is directly related to the streaming velocity. The equation that in first approximation describes the streaming velocity is Following equation it can be concluded that – the thinner the file, the higher the frequency and the greater the displacement amplitude of the file, the higher the streaming velocity and the more powerful the acoustic microstreaming will be. Ʋ = liquid streaming velocity ω = 2 π times the driving frequency =displacement amplitude a = the radius of the wire

79. IRRIGATION… PRE-REQUISITES Canal must be enlarged to size 30 to 40 atleast for the space required for the motion of the file, as the narrow canal will dampen the motion and therefore rendering it ineffective. Use of proper irrigant such as NaOCl Smaller file---- Greater Amplitude-----Greater Acoustic Streaming COMPLICATIONS Straightening of canal ( transportation) Perforation Extrusion of infectious material beyond apex

80. IRRIGATION… Passive ultrasonic irrigation was first described by Weller et al. (1980). The term ‘passive’ does not adequately describe the process, as it is in fact active; however, when it was first introduced the term ‘passive’ related to the ‘noncutting’ action of the ultrasonically activated file. PUI relies on the transmission of acoustic energy from an oscillating file or smooth wire to an irrigant in the root canal. The energy is transmitted by means of ultrasonic waves and can induce acoustic streaming and cavitation of the irrigant.

81. IRRIGATION… Two types of ultrasonic irrigation have been described: one where irrigation is combined with simultaneous ultrasonic instrumentation (UI) without simultaneous instrumentation, so called passive ultrasonic irrigation (PUI). During UI the file is intentionally brought into contact with the root canal wall. UI has been shown to be less effective in removing simulated pulp tissue from the root canal system or smear layer from the root canal wall than PUI UI could result in uncontrolled cutting of the root canal wall without effective cleaning.

82. IRRIGATION… Procedure Root canal shaped to the master apical file A small file or smooth wire is introduced in the centre of the root canal, as far as the apical region Root canal is then filled with an irrigant solution Ultrasonically oscillating file activates the irrigant Using this noncutting methodology, the potential to create aberrant shapes within the root canal will be reduced to a minimum.

83. IRRIGATION… Mechanism of passive ultrasonic irrigation Frequency and intensity Electrical energy ultrasonic waves of a certain frequency piezoelectricity magnetostriction Piezoelectricity is the generation of stress in dielectric crystals subjected to an applied voltage. Magnetostriction is generated by the deformation of a ferromagnetic material subjected to a magnetic field;

84. IRRIGATION… Frequency of the oscillating instrument, in dental practice, is fixed at 30 kHz. The intensity or energy flux, expressed in units of Watt cm -2 , of the oscillating instrument can be adjusted by the power setting. A higher frequency should in principle result in a higher streaming velocity of the irrigant. This in turn results in a more powerful acoustic streaming. Increasing the intensity does not result in a linear increase of the displacement amplitude of the oscillating file.

85. IRRIGATION… The effects and use of PUI (passive ultrasonic irrigation) PUI versus syringe irrigation – From the studies where PUI and syringe irrigation were compared, it can be concluded that PUI is more effective in removing remnants of pulp tissue and dentine debris. Removal of the smear layer – When 3% NaOCl was used complete removal of smear layer with 3 and 5 min and after 20 s with 5.25% NaOCl using PUI. Did not enhance the removal of the smear layer when EDTA or a combination of EDTA and NaOCl was but significantly improved the smear layer removal of Savlon (0.03% chlorhexidine , 0.3% cetrimide )

86. IRRIGATION… The effects and use of PUI PUI with NaOCl as irrigant – During PUI, NaOCl removes significantly more smear layer or bacteria from artificial smear layer, pulp tissue or dentine debris from the root canal than water. Heating of irrigant and root surface during PUI A rise of the intracanal temperature from 37 to 45°C close to the tip of the instrument and 37°C away from the tip when the irrigant was ultrasonically activated for 30 s without replenishment. A cooling effect from 37 to 29°C was recorded when the irrigant was replenished with a continuous flow of irrigant .

87. IRRIGATION… The effects and use of PUI Ultrasonic versus sonic irrigation – Sonic irrigation is different from ultrasonic irrigation because it operates at a lower frequency. For sonic application the frequencies ranges from 1000 to 6000 Hz. Consequently, following previous equation, the streaming velocity of the irrigant will be lower. Moreover, the oscillating patterns of the sonic instruments are different. They have one node near the attachment of the file and one antinode at the tip of the file. When the movement of the sonic file is constrained, the sideway movement will disappear, but will result in a longitudinal vibration. The positive relationship between streaming velocity and frequency can explain the higher efficiency of PUI versus sonic irrigation.

88. IRRIGATION… PUI parameters Taper of the file and diameter of the root canal – greater the taper the more dentine debris can be removed. Application of irrigant during PUI Two flushing methods can be used during PUI, namely - a continuous flush of irrigant from the ultrasonic handpiece an intermittent flush method using syringe delivery (Cameron 1988). In the intermittent flush method, the irrigant is injected into the root canal by a syringe, and replenished several times after each ultrasonic activation. Both flushing methods were equally effective in removing dentine debris.

89. IRRIGATION… PUI parameters Irrigation time 3 – 5 mins PUI with a smooth wire A smooth wire is as effective as a normal cutting file in dentine debris removal during PUI. It seems preferable to use a smooth wire during PUI because it does not intentionally cut into the root canal wall and it may, therefore, prevent aberrant root canal shapes or perforation of the (apical) root.

90. IRRIGATION… SONICALLY ACTIVATED IRRIGATION ENDOACTIVATOR ( DENTSPLY Tulsa ) INTRODUCTION Clifford J. Ruddle Robert H. Sharp Pierre Machtou PRINCIPLE sonically activated causing Cavitation and photoacoustic streaming.

91. IRRIGATION… DESIGN The EndoActivator Tips are 22 mm in length and are available in three sizes:.........small - (15/02) medium - (25/04) large -(35/04) Color-coded by size for easy identification Convenient depth gauge rings at 18, 19 and 20 mm. INDICATIONS Debridement and disruption of the smear layer and biofilm. Placement of calcium hydroxide and MTA around root curvatures. Removal of residual obturation materials during retreatment procedures.

92. The Er : YAG laser wavelength (2940nm) has the highest absorption in water and high affinity to hydroxyapatite. Laser energy may be used to activate irrigant solutions in different ways for example., at molecular level, photoactivated disinfection, or bulk flow level as in laser activated irrigation. Several studies indicated that laser activated irrigation is promising in removing smear layer and dentin debris in less time than PUI. The mechanism of action is based on the generation of secondary cavitation effect with expansion and the successive implosion of fluids. IRRIGATION… Laser:-

93. Antimicrobial photodynamic therapy is a 2 step procedure that involves the introduction of a photo sensitizer followed by illumination of the sensitized tissue, which would generate a toxic photochemistry on the target cell, leading to cell lysis . Each of these elements used independently will not have any action, but together they have synergism effect of producing antibacterial action IRRIGATION… Photo activated disinfection Principle:-

94. The Nanoparticles evaluated in endodontics includes Chitosan (CS- np ), zinc oxide ( ZnO-np ), and silver ( Ag_np ) nanoparticles . CS- np effective against mono species (E. Faecalis ) and multispecies biofilms , even in the presence of tissue inhibitor , and it has been attributed to their ability to disrupt the cell wall. Silver nanoparticles are evaluated for use as root canal disinfecting agents. In gel and liquid form, such nanoparticles have been shown to be able to kill and disrupt E. Faecalis biofilm . IRRIGATION… Antibacterial nanoparticles :-

95. REFERENCES: Sedgley C. Root canal irrigation--a historical perspective. J Hist Dent. 2004 Jul;52(2):61-5. PMID: 15293717. Cohen 12 th edition

96. Thank you