13 - Implant Failures (1).pptx in prostho

Implant failures in Prosthodontics

1. GOOD MORNING 1

2. IMPLANT FAILURES ARIF JALAL 3 RD YEAR PG DEPT. OF PROSTHODONTICS 2

3. 1 INRODUCTION 2 DEFINITIONS 3 PREDICTORS OF IMPLANT SUCCESS AND FAILURE 4 WARNING SIGNS OF IMPLANT FAILURES 5 CRITERIA FOR IMPLANT SUCCESS CONTENTS 3

4. 6 IMPLANT QUALITY SCALE 7 CLASSIFICATION OF IMPLANT FAILURES 8 COMPLICATIONS AND MANAGEMENT 9 IMPLANT MAINTENANCE 1 CONCLUSION 1 1 REFERENCES 4

5. INTRODUCTION 5

6. Implant dentistry is currently being practiced in an atmosphere of enthusiasm and optimism, because our knowledge and ability to provide service to our patients has expanded so greatly in such a short period. But Success cannot be guaranteed, what one can guarantee is to care, to do ones best and to be there to help in the rare instance that something goes wrong . 6

7. ………When I mplant fails…… T hen………. The S urgeon’s tale : ‘The implants were successfully integrated , but failed because of excess loads. The Restorative Dentist’s tale : ‘The implants were poorly integrated and so failed under normal masticatory loads.’ either way . The Patient’s tale : ‘My implants have failed!’ 7

8. Actually Success & Failure of the implants depends upon team work i.e. the co-operation b/w : Surgeon Prosthodontist Periodontist L ab technician Patient. 8

9. DEFINITIONS 9

10. IMPLANT (1890) : To graft or insert a material such as an alloplastic substance, anencapsulated drug, or tissue into the body of a recipient. - GPT 10 IMPLANT FAILURE : It is defined as total failure of the implant to fulfill its purpose (functional, esthetic or phonetic) because of mechanical or biological reasons. (Askary et al ID 1999 vol8 no2 173-183) 10

11. Ailing implants : Those that show radiographic bone loss without inflammatory signs or mobility. Failing Implant : Characterized by progressive bone loss, signs of inflammation and no mobility. 11

12. Failed Implants : Those with progressive bone loss, with clinical mobility and that which are not functioning in the intended sense. Surviving implants : Described by Alberktson, that applies to implants that are still in function but have been tested against the success criteria. 12

13. PREDICTORS OF IMPLANT SUCCESS & FAILURE 13

14. Bone type (Type 1and 2). Patient less than 60yrs old. Experienced Clinician. Mandibular placement. Implant length > 8mm. (General dentistry 2005, 423-432) POSITIVE FACTORS FPD with more than two implants. Axial loading of implant. Regular postoperative recalls. Good oral hygiene. 14

15. Bone type (Type 3 and 4). Low bone volume. Patient more than 60yrs old. Limited clinician experience. Systemic diseases. Auto-immune diseases. Chronic periodontitis. Smoking and tobacco use. NEGATIVE FACTORS Unresolved caries, endodontic lesions,frank pathology. Maxillary, particularly posterior region. Short implants (<7mm). Eccentric loading. Inappropriate early clinical loading. Bruxism and other parafunctional habits. 15

16. WARNING SIGNS OF IMPLANT FAILURE 16

17. Connecting screw loosening . Connecting screw fracture . Gingival bleeding and enlargement . Purulent exudates from large pockets . Pain . (Askary et al ID 1999; vol 8; no2, 173-183) SIGNS Fracture of prosthetic components . Angular bone loss noted radiographically . Long-standing infection and soft tissue sloughing during the healing period of first stage surger y. 17

18. CRITERIA FOR IMPLANT SUCCESS 18

19. I ndividual implant is immobile when tested clinically. No radiographic evidence of peri-implant radiolucency . Bone loss no greater than 0.2 mm annually . Gingival inflammation amenable to treatment . (Albrekfsson T. :int J. Oral Maxillofac Implants 1986; 1:11-25) CRITERIAS 19

20. CRITERIAS Absence of symptoms of infection and pain . Absence of damage to adjacent teeth . Absence of parasthesia, anesthesia or violation of the mandibular canal or M axillary sinus . P rovide functional survival for 5 years in 90% of the cases and for 10 years in 85%. 20

21. IMPLANT QUALITY SCALE 21

22. The scale presented for implant quality of health based on clinical evaluation was first suggested by James and was modified by Misch . This quality of health scale criteria, has to be place in the appropriate category, and then treat the implant accordingly. The prognosis also is related to the quality scale. . 22

23. Group I (Optimal Health) No pain, tenderness on palpation & purcussion. Rigid fixation, no horizontal & vertical mobility under 500g load. <1.5mm crestsl bone loss from Stage II. <1.0mm crestal bone loss preceding 3 yrs. After 1 yr - Stable probing depth (<4mm). No exudate history. No radiolucency. 0-1 bleeding index GENERAL CONDITIONS 23

24. Group II (Satisfactory Health) No pain, tenderness on palpation & purcussion. Rigid fixation, no horizontal & vertical mobility under 500g load. <1.5-3mm crestsl bone loss from Stage II. <1.0mm crestal bone loss preceding 3 yrs. After 1 yr - May be 4mm probing depth from original tissue thickness - but stable in last 3 yr period. Past transient exudate history. No radiolucency. 0-1 bleeding index - May have 2 transient condition. 24

25. Group III (Compromised Health) No pain on palpation & purcussion. Mild tenderness. Initial rigid fixation, 0-0.5mm horizontal mobility after prosthesis delivery & No vertical mobility. >3mm crestal bone loss the 1 st yr. >1.0mm crestal bone loss preceding 3 yrs, But <1/2 total bone loss (implantitis). Probing depth is >5mm and incresing in preceding 3yrs. History of exudate for 1-2wks in last 3 yrs. Slight radiolucency at the crestal level of implant. 1-3 bleeding index. 25

26. Group IV (Clinical failure) Pain on palpation & purcussion or function. Mild tenderness. >0.5mm horizontal mobility & any vertical mobility. Uncontrtolled progressive bone loss. More than half bone loass supporting the implant. Uncontrolled exudate. Generalized radiolucency. Sleepers. 26

27. Group V (Absolute failure) Implants surgically removed. Implants exfoliated. 27

28. Group I (Optimal Health) Normal Maintenance. Group II (Satisfactory Health) Reduce stresses. Shorter intervals for hygiene appointments. Gingivoplasy. Yearly Radiographs. MANAGEMENT 28

29. Group III (Compromised Health) Drug therapy. Antibiotics. Chlorhexidine. Surgical reentry. Revision surgery. Change in prosthesis or implants. Group IV (Clinical failure) Removal of implant. 29

30. Group V (Absolute failure) Bone Graft. 30

31. CLASSIFICATION 31

32. . 32

33. Infectious Failure : Clinical signs of infection with classic symptoms of inflammation. High plaque and gingival indices. Pocketing, Bleeding, Suppuration. E.S Rosenberg, J.P. Torosian and J. Slots . Attachment loss. Radiographic peri-implant radiolucency. Presence of granulomatous tissue upon removal. 33

34. Traumatic Failure : Radiographic periimplant radiolucency. Mobility. Lack of granulomatous tissue upon removal. Lack of increased probing depths. Low plaque and gingival indices. 34

35. Biological Failures : Early or primary (Before loading). Late or secondary (After loading). Mechanical failures : Fracture of Implants, Connecting screws, Bridge framework, Coatings etc. Marco Esposito, Jan Michael Hirsh, Ulf Lekholm et al - Osseointegration concept. Iatrogenic Failures : Improper implant angulation and Alignment, Nerve damage. Inadequate Patient adaptation : Phonetics, Esthetics, Psychological problems. 35

36. Early Failures : Causes attributed are : Surgical trauma. Insufficient quantity or quality of bone. Premature loading of implant. Bacterial infection. Kees Heydenrijik, Henny JA Meijer, Wil A Van der et al - O ccurrence in time 36

37. Late Failures : Soon late failures : Implants failing during first year of loading. Overloading in relation to poor bone quality and insufficient bone volume. Delayed late failures : Implant failing in subsequent years. Progressive changes of the loading conditions in relation to bone quality, volume and peri -implantitis. 37

38. Swedish Team ( Branemark et al) : Loss of bone anchorage : Mucoperiosteal perforation. Surgical trauma. Gingival problems : Proliferative gingivitis. Fistula formation. Mechanical complications : Fracture of prosthesis, gold screws, abutment screws. Sumiya Hobo, Eiji Ichida, Lily T Garcia - C omplications occurring in implants 38

39. U.C.L.A team (Beumer, Moy) : Complications in Stage I surgery. Complications in Stage II surgery. Prosthetic complications. 39

40. According to Etiology : Host factor. Surgical factor. Implant selection factor. Restorative factor. According to Timing of failure : Before stage II. After stage II. After restoration. Abdel Salam el Askary, Roland Meffert and terrence griffin (1999) 40

41. According to Origin of infection: Peri- implantitis Infective process. Bacterial origin. Retrograde peri-implantitis. Traumatic occlusion origin. Non infective. Forces off the long axis. Premature or excessive loading. 41

42. According to Failure mode : Lack of osseointegration. Unacceptable aesthetics. Functional problems. Psychological problems. According to Condition of failure : Ailing Implant. Failing Implant. Failed Implant. Surviving Implant. 42

43. According to Supporting tissue type : Soft tissue loss. Bone loss. Combination. According to Responsible personnel : Dentist (Oral surgeon, Prosthodontist, Periodontist). Dental hygienist. Laboratory Technician. Patient. 43

44. HOST FACTOR Medical status. Habits. Parafuctional Habits. Oral status. Irradiation therapy. ACCORDING TO ETIOLOGY 44

45. MEDICAL STATUS M edical history is essential to rule out any of the following conditions or disorders. Autoimmune : S jogren syndrome . SLE . S cleroderma . HIV . CV Di s eases : Hypertension . MI . Congestive heart failure . SABE .  45

46. Endocrine : DM . Thyroid disorders . Pregnancy : Avoid to place implant in pregnancy . In all these conditions, chances of success rate are poor , but implant therapy not contraindicated except few. Bone di s eases : O steoporosis . O steomalacia . H yperparathyriodism . F ibrous dysplasia . P aget d isease. M ultip le myeloma . O steomylitis . 46

47. HABITS Smoking : Significance : Causes alveolar vasoconstriction and decreased blood flow. Impaired wound healing due to compromised polymorphonuclear leucocytes function, increased platelet adhesiveness as well as vasoconstriction caused by nicotine. Poor bone quality. In case of poor oral hygiene, smokers have 3 times more marginal bone loss then non-smokers. 47

48. Recommendations : Obtain a smoking history. Advice on risks of periodontal breakdown. Advice on the prognosis. Smoking cessation 48

49. PARAFUNCTIONAL HABITS Bruxism & Clenching : Bruxism is the multidirectional nonfunctional grinding of teeth. Clenching occurs in one direction (vertically). Bruxism is more aggressive. Attrition usually appears on the incisal edges of anterior teeth. 49

50. Significance : Most common cause of implant bone loss or lack of rigid fixation during the first year after implant insertion. Commonly manifests as connecting screw loosening because of overload. Failures are higher in maxilla because of decrease in bone density. Forces are in excess of normal physiologic masticatory load limit. 50

51. Prevention : Increased number of implants to be placed. Avoid cantilevers and occlusal contacts in lateral excursions. Use of occlusal splint which is relieved over the implant. Use of wide diameter implant to provide greater surface area. Progressive bone loading and prosthetic design that improves the distribution of stresses throughout the implant system. 51

52. ORAL STATUS Poor home care: Suprabony connective tissue fibers are oriented parallel to the implant surface. Susceptible to plaque accumulation and bacterial ingress. Spontaneous loss of the perimucosal seal. Chances of implant failure increases. 52

53. Prevention : It is recommended that the patient be recalled frequently, preferably at a minimum of 3 months intervals. Periodontal indices, bleeding on probing and radiographic evaluation should be performed, using plastic tipped probes for checking pocket depths. 53

54. Soft tissue debridement can be performed by means of plastic curettes and plastic tips for ultrasonic scalers, and topical and systematic antimicrobial drugs should be used. Provide space beneath the superstructure to allow cleansing aids. 54

55. IRRADIATION THERAPY Significance : Xerostomia. Susceptibility to infection. Osteoradionecrosis. Endarteritis of vessels causes decrease in oxygen supply. 55

56. Prevention : Waiting period of 9-12 month between radiation therapy and implant treatment. Hyperbaric oxygen therapy – 20 treatments of 90 min. each at 2 to 2.4atm before surgery. Antibiotic regimen 3 days before (Augmentin 500mg every 12 hrs) 56

57. SURGICAL PLACEMENT Impaired healing and infection due to improper flap design . Overheating the bone and E xerting too much pressure . Contamination of implant body before insertion . Placement of implant in immature bone grafted site . Severe angulation . Minimum space between implants . Lack of initial stabilization . ACCORDING TO ETIOLOGY 57

58. OFF-AXIS PLACEMENT (SEVERE ANGULATION) Due to : Alveolar process resorption. Unexperienced surgeon. Improper surgical stent. Problem : Occlusal load lie at an angle. Shear & tensile forces increases. Chances of failure increases. 58

59. Solutions : Prerestoring the implant position by grafting. To place the implant with an angulation. To place angulated abutments. Surgical guides can be used. 59

60. LACK OF INITIAL STABILITY Due to : Oversized osteotomy. Gap develop between implant & bone. Lack of osseointegration. 60

61. Solution : Remove & Reinsert the larger size implant. If not possible : Remove implant Insert HA graft material. Roll the implant moistened in blood & saline & in the particulate slurry until thin layer of slurry clings to it. Reinsert the implant. 61

62. In an experimental investigation : Gaps in the range of 0.25 mm around CPTi implants healed, but with less bone contact than the controls. When the gap size increased to 0.7mm-1.7mm, a thin soft tissue layer was found to develop around the implant. Upadhyay, Amrita & Chamadia, Amyn & Bashir, Ruquaya. (2022). Cause of Implant complication and management. 62

63. Improper healing & infection because of improper flap design No single flap design is optimal for implant surgery. But improper flap design promotes infection & bacterial ingress and leads to chances of failure increases. Note: Basic surgical procedure, Flap design, Blood supply, Visibility, Access, Primary closure should be considered. 63

64. Overheating the bone and exerting too much pressure Excessive pressure. Bone cell damage. Bone loss. Connective tissue interface formed. Failure increases. 64

65. Inverse relationship b/w speed & heat production. Bone cell death occurs at a temperature of 47 degree and higher when drilling is performed for 1 minute. Solution : Recommended speed- 2000 rpm with graded series of drill size with external irrigation. 65

66. Placement of implant in immature bone grafted site Minimum waiting period of grafted site 6-9 month. Woven bone present before this period, which is fastest formed bone (partly mineralized & Unorganized). Not suitable for implant - Bone integration. Lamellar bone - Ideal for implant prosthetic support. 66

67. Contamination of implant body before insertion Due to : Non-titanium instrument. By glove powder. By the operatory error. 67

68. Solution : Implant should be cleaned with radiofrequency glow discharge unit or plasma cleaner. Metal instrument should be titanium tipped. 68

69. IMPLANT SELECTION FACTOR Improper implant type in improper bone type . L ength of the implant . W idth of the implant . N umber of the implant . I mproper implant design . ACCORDING TO ETIOLOGY 69

70. Length of the implant Misch proposed the range of 10mm -16mm length. The success rate is proportional to the implant length and the quantity and quality of available bone. The rate of failure can be expected to rise proportionately as the depth of the bone diminishes to less than 10mm. 70

71. The greater the crown implant ratio, the greater the amount of the force with any lateral force. This means that the implant with unfavorable crown implant ratio will be more influenced by lateral forces. Therefore, maximum implant length must be used for the greatest stability of the overlying prosthesis. 71

72. WIDTH of the implant Misch recommended that not less than 1 mm of bone surrounding the fixture labially and lingually is mandatory for the long term predictability of dental implants because it maintains enough bone thickness and blood supply. It is advisable to use a large- diameter implant in accordance with the available bone width because it offers greater surface area, greater mechanical engagement of the cortical bone, and initial rigidity. 72

73. Using a wide implant in a narrow ridge results in labial or lingual dehiscence that leaves the implant affected by the damaging shear stresses. 73

74. NUMBER of the implantS Misch stated that the use of more implants decreases the number of pontics and the associated mechanics and strains on the prosthesis, and dissipates stresses more effectively to the bone structure. It also increases the implant bone interface and improve the ability of the fixed restoration to withstand forces. 74

75. Contrary to this Smith et al correlated between the increased number of implants and the high failure rate caused by wound contamination that might occur because of the long operating time. 75

76. RESTORATIVE PROBLEMS E xcessive Cantilever . Connecting implants to natural teeth . Pier abutments . No passive fit . Improper fit of the abutment . Bending moments . Improper occlusal scheme . ACCORDING TO ETIOLOGY 76

77. Excessive cantilevers Used implant-supported prosthesis. Mesial C. > Distal C. 77

78. Cantilever extensions cause load magnification and overloading of the implant next to the cantilever extension, which in turn leads to bone loss. With occlusal forces acting on the cantilever, the implant becomes a fulcrum and is subjected to rotational forces. 78

79. Amount of force increases : Length of cantilever. Distance between implants. Crown height. Direction of force. Position of arch. Amount of force less : Opposing arch ideally a denture. No lateral forces on cantilever. Not preferred : Moderate to severe parafunctional habits 79

80. CONNECTING IMPLANTS TO TEETH 80

81. Solution : Increase no. of implants. Improve stress distribution by splinting additional abutment until zero clinical mobility is observed. Non-rigid connection – but chances of intrusion of the tooth. Criteria : No observable clinical mobility of natural abutment. No lateral force should be designed on prosthesis. 81

82. PIER ABUTMENTS Main complication due to difference of mobility of tooth & implant. 2 situations occurs: Implant as pier - Act as class 1 lever - Non rigid attachment. 82

83. Tooth as pier - Tooth act as living pontic or pontic with a root. Stress breaker - Not indicated 83

84. NO PASSIVE FIT For a long- term success of multiple implant restoration - passive fit between the framework and the underlying fixtures. A passive fit reduces long term stresses in the superstructure, implant components, and bone adjacent to the implants. 84

85. A poorly fitting implant framework can cause mechanical complications such as loose screws or fractured components. 85

86. IMPROPER FIT OF ABUTMENT Improper locking b/w abutment-fixture interface. Increased microbial population & increased strain on implant component. Bone loss. Rapid screw-joint failure. 86

87. IMPROPER OCCLUSAL SCHEME Important guidelines to follow : Infraocclusion upto 30 microns of implant supported restoration. No balancing contacts on cantilevers. No guidance on single implants. 87

88. Occlusal table directly proportional to implant diameter. Implant length : Crown-root ratio ideal – 1:2 Acceptable – 1:1 for removable denture. Avoidance of cantilever length : Maximum 10 to 15 mm is advised. 7 mm is optimum . 88

89. Shallow central fossae with tripodal cuspal contacts. Freedom in centric. No contact in lateral excursion. Narrow occlusal width. Slight contact in centric occlusion. 89

90. IMPLANT FAILURES ARIF JALAL 3 RD YEAR PG DEPT. OF PROSTHODONTICS 2 2 nd SESSION

91. 1 INTRODUCTION 2 DEFINITIONS 3 PREDICTORS OF IMPLANT SUCCESS AND FAILURE 4 WARNING SIGNS OF IMPLANT FAILURES 5 CRITERIA FOR IMPLANT SUCCESS CONTENTS 3

92. 6 IMPLANT QUALITY SCALE 7 CLASSIFICATION OF IMPLANT FAILURES 8 COMPLICATIONS AND MANAGEMENT 9 IMPLANT MAINTENANCE 1 CONCLUSION 1 1 REFERENCES 4

93. Lack of Osseointegration Functional Problems Unacceptable Aesthetics Psychological Problems ACCORDING TO FAILURE MODE 90

94. Lack of Osseointegration : Adell et al proposed that lack of osseointegration can be due to : Surgical trauma. Perforation through covering mucoperiosteum during healing. Repeated overloading with microfractures of the bone at early stages. 91

95. Functional problems : Proper function of the implants is dependent on two main types of : Anchorage related factor - Osseo integration & Marginal bone height Prosthesis related factor - Prosthesis design Occlusal scheme 92

96. Aesthetic problem : Aesthetic outcome is affected by four factors : Implant placement Soft tissue management Bone grafting consideration Prosthetic consideration. 93

97. Psychological problems : High expectations of the patient. 94

98. Soft tissue problems. Bone loss. Both soft tissue and bone loss. ACCORDING TO SUPPORTING TISSUE TYPE 95

99. SOFT TISSUE PROBLEMS : Gingival loss leads to continuous recession around the implant with subsequent bone loss - Lead to a Soft tissue type of failure. Significance of attached gingiva surrounding implants : Facilitates impression making. Provide tight collar around the implant. Prevent recession of marginal gingiva. Prevent spread of inflammation to deep tissue. 96

100. BONE LOSS : Bone functions as a support for the implant and that any disturbance in its function may lead to eventual loss of the implant. Loss of marginal bone occurs both during the healing period and after abutment connection. Bone loss in mandible is higher during the healing period, whereas in maxilla , bone loss is higher after abutment connection. 97

101. Factors that contribute to Marginal bone loss : Surgical trauma , detachment of the periosteum and damage caused during drilling. Improper stress distribution caused by defective prosthetic design and occlusal trauma. Gingivitis - lead to ingression of bacteria & their toxins to underlying osseous structures. Physiological ridge resorption. 98

102. BOTH SOFT TISSUE & BONE LOSS : If failure starts from S oft tissue, then it usually is considered to be due to a Bacterial factor . If failure starts at the B one level, then it is considered to be due to a Mechanical factor . Both bone and soft tissue may be involved together. 99

103. Peri implantitis. Retrograde peri implantitis. ACCORDING TO ORIGIN OF INFECTION 100

104. Progressive peri-implant bone loss in conjunction with a soft tissue inflammatory lesion is termed peri-implantitis. Definition : I nflammatory lesion of the mucosa surrounding an endosseous implant and with progressive loss of supporting peri-implant bone. - American Academy of Periodontology PERI IMPLANTITIS 101

105. Two primary E tiological factors : Bacterial infection . Biomechanical overload . (Newman et al 1988, 1992, Rosenberg et al 1991) 102

106. RISK FACTORS : Previous periodontal disease. Poor plaque control. Residual cement. Smoking. 103 Genetic factors. Diabetes mellitus. Occlusal overload. Microgap & Biofilm growth.

107. CLINICAL FEATURES : Suppuration. BOP. Progression of pocket depth. 104 Inflammatory reaction of mucosa. Mobility. Radiographically detectable bone loss.

108. Classification of peri-implantitis : (JOVANOVIC 1995) Class I : Slight Horizontal bone loss with minimal Peri-implant defects. Treatment : Initial therapy for removal of etiological factors. Surgical therapy : Cleaning the implant surface. Pocket elimination via Apical positioning of flap. 105

109. Class II : Moderate horizontal bone loss with isolated vertical defects. Treatment : Initial therapy for removal of etiological factors. Surgical therapy : Cleaning the implant surface pocket. Elimination and adjunctive treatment using systemic antimicrobials. 106

110. Class III : Moderate to advanced horizontal bone loss with broad, circular bony defects. Treatment : Initial therapy for removal of etiological factors. Surgical therapy : Cleaning the implant surface. Pocket elimination via osseous regeneration and adjunctive antibiotic treatment. 107

111. Class IV : Advanced horizontal bone loss with broad circumferential vertical defects as well as loss of buccal and lingual bony wall. Treatment : Initial therapy for removal of etiological factors. Surgical therapy : Cleaning the implant surface. Pocket elimination via bone regeneration techniques. Autologous bone transplants with adjunctive antibiotic therapy. 108 Shrestha R, Bhochhibhoya A. Peri-implantitis: A Classification Update. Nepal J Health Sci. 2021 Jul-Dec; 1(2): 52-62

112. TREATMENT OF PERI-IMPLANTITIS : Non-surgical : Local debridement Air abrasion Detoxification Laser therapy Photodynamic therapy Drug therapy 109

113. TREATMENT OF PERI-IMPLANTITIS : Surgical : Resective surgery. Regenerative surgery. Implantoplasy. 110

114. Ailing Implant. Failing Implant. Failed Implant. Surviving Implant. ACCORDING TO CONDITION OF FAILURE 111

115. Clinical signs : P rogressive bone loss . S oft tissue pockets and crestal bone loss . B leeding on probing with possible purulence . T enderness to percussion or torque forces . FAILING IMPLANT 112

116. Causes : O verheating of bone at the time of surgery or lack of initial stability. I nadequate screw joint closure . F unctional overload . P eriodontal infection (peri-implantitis) . 113

117. T reatment : R emove prosthesis and abutments . I rrigate with Peridex . U ltrasonic and disinfect all components . R einsert assuring proper screw torque . R echeck passive fit of framework and occlusion 114

118. Clinical signs : Mobility - V erify fixture mobility by removing any abutments and superstructures first. “Dull” percussion sound . Peri-implant radiolucency . FAILED IMPLANT 115

119. Causes : S urgical compromise (overheating bone and initial lack of stability). Inadequate screw joint closure . Too rapid initial loading . Functional overload . Periodontal infection (“peri-implantitis”) . 116

120. T reatment : R emov al of the implant. 117

121. COMPLICATIONS AND MANAGEMENT 118

122. Before Stage II After Stage II After Restoration ACCORDING TO TIMING OF FAILURE 119

123. BEFORE STAGE II PROBLEM POSSIBLE CAUSE SOLUTION Hemorrhage during drilling . Lesion or injury of an artery . I mplant placement will stop the bleeding. Simple tamponade, B one wax, G elfoam , S urgicel , A vitene can also be used . Exposed implant threads . Too narrow crest . Cover the threads with coagulum or place a membrane . 120

124. PROBLEM POSSIBLE CAUSE SOLUTION Implant mobility after placement . Soft bone . Imprecise preparation . Remove the implant and replace with larger diameter. If the mobility is small prolong the healing time . Swelling lingually directly after implant placement at the mandibular symphysis . Incision of an artery branch sublingually . S end the patient to a specialist center for coagulation of the artery under GA. 121

125. Injury to neurovascular bundle The posterior mandible in particular presents significant challenge when severe atrophy leaves little, if any bone superior to inferior alveolar canal. The solution to limited space for posterior mandible fixture placement includes detailed initial treatment planning and careful surgery to unroof the canal and move the neurovascular bundle inferiorly prior to fixture installation. 122

126. AFTER STAGE II PROBLEM POSSIBLE CAUSE SOLUTION Slightly sensitive but perfectly immobile implant. Imperfect osseointegration. Cover the implant for 2-3 months and test again. Exposed implant threads . Too narrow crest . Cover the threads with coagulum or place a membrane . Slightly painful and mobile implant. Lack of integration. Remove the implant. 123

127. PROBLEM POSSIBLE CAUSE SOLUTION Difficulty inserting a transfer screw, gold screw or healing cap . Damaged inner thread of abutment screw . Change the abutment screw. Inability to perfectly connect the abutment to the implant. Insufficient bone milling . Under LA, use a bone mill with guide, remove the bone, clean with saline solution, and replace the abutment. 124

128. PROBLEM POSSIBLE CAUSE SOLUTION Granulation tissue around the implant head. Traumatic placement of the implant. Compression from the transition prosthesis. Open the area and disinfect with chlorhexidine. If the lesion is too large, consider a bone regeneration or grafting technique. 125

129. AFTER RESTORATION PROBLEM POSSIBLE CAUSE SOLUTION Pain or sensation when tightening gold screws (during try in of prosthesis). Misfit between prosthesis and abutments. Cut the prosthesis; interlock the pieces, and solder the prosthesis at the laboratory. Retry the prosthesis. Loosening of one or more prosthetic screws at the first inspection after two week. Occlusal problem. Retighten, verify the occlusion, and recheck after two weeks. 126

130. PROBLEM POSSIBLE CAUSE SOLUTION Loosening of prosthetic screws at the second check or later. Occlusal problem or misfit between prosthesis and abutments. Too large extension. Unfavourable prosthetic concept. Verify the occlusion and/ or the prosthetic fit. Reduce the extension. Change the prosthetic design. In all cases, change the prosthetic screws. 127

131. PROBLEM POSSIBLE CAUSE SOLUTION Fracture of a prosthetic screw or an abutment screw. Occlusal problem, lack of fit between the prosthesis and the abutment or unfavourable prosthetic design. If the occlusion or the adaptation of the prosthesis seems right, modify the prosthetic design (reduce or eliminate extensions, reduce the width of occlusal surfaces, reduce cuspal inclination, add implants, etc). 128

132. 129 PROBLEM POSSIBLE CAUSE SOLUTION Fracture of the framework. Weak metal frame end or too large extension. Bruxism / Parafunction. Remake the prosthesis. Modify the prosthetic design (reduce or eliminate extensions, reduce width and height of occlusal surfaces, reduce cusp inclination, add implants, etc). Make a nightguard.

133. . 130 PROBLEM POSSIBLE CAUSE SOLUTION Implant fracture. Occlusal overload Remove the implant with a special trephine drill, wait 2- 6 months, if possible, and place a wider implant. Review the prosthetic design (place more implants, etc) and remake the prosthesis.

134. . PROBLEM POSSIBLE CAUSE SOLUTION Continuing bone loss around one or more implants. Infection (peri- implantitis). Remove the etiolgical factors (poor plaque control, prosthesis geometry in relation to the mucosa, etc). Look for bacterial pockets around the natural teeth. Possibly make a bacteria test. Cut open the lesion. Adjust the peri-implant tissues (gingival graft). Consider a bone regeneration procedure. 131

135. . PROBLEM POSSIBLE CAUSE SOLUTION Continuing bone loss around one or more implants. Occlusal overload Modify the prosthetic design (reduce or eliminate extensions, reduce the width of occlusal surfaces, reduce cuspal inclination, add implants, etc) 132

136. These are primarily related to failure of prosthodontic materials to resist forces and stresses of oral function. 133 MECHANICAL COMPLICATIONS

137. Tip of the explorer is placed on the top portion of the fractured abutment screw. With slight apical pressure and a counterclockwise circular motion, the fragment can often be unscrewed. Care must be taken not to damage the internal threads of the implant. FRACTURED ABUTMENT SCREW 134

138. When Screw Fragment removed, replace with appropriate new abutment and screw. Verify seating with a radiograph prior to final torque. Replace prosthesis and secure with new retention screws. 135

139. Radiographic evaluation of a loose healing abutment. Removal of healing abutment indicates a distorted screw . Treatment : Replace with new healing abutment LOOSE HEALING ABUTMENT 136

140. Radiograph confirms poor seating abutment. Clinical evaluation after removal of bar indicates loose abutment screw. Diagnosis : P ossible loose or fractured abutment screw . LOOSE BAR 137

141. Treatment : Retorque abutment screw . Treatment continued - Abutment screw is tightened with abutment driver. Bar is then replaced and prosthetic screws are torqued with appropriate screw driver. 138

142. Radiographic Evaluation : Small opening at a butment-implant interface . Diagnosis: Loose abutment screw . LOOSE RESTORATION 139

143. Treatment : Loosen screw and R emove restoration . Inspect the implant hex for damage. Inspect the restoration for damage : Implant Hex & Abutment Hex. No Damage to fixture or Restoration : Replace restoration and secure with the same screw. Verify seating with radiograph prior to final torque. Recheck occlusion with shimstock . 140

144. Damaged Fixture Hex and or Restoration : Replace restoration Secure with appropriate new screw. 141

145. Treatment : Eventual implant removal . FRACTURED IMPLANT FIXTURE HEAD 142

146. Many implant components are as small as are the instruments used for their manipulation. When coated with saliva a component may escape the clinicians grip and fall into the oropharynx, reflex swallowing may take the component out of site almost immediately. ACCIDENTAL SWALLOWING / INHALATION OF COMPONENTS OR INSTRUMENTS 143

147. Prevention : Manual screwdrivers and similar instruments should always be equipped with a safety line of dental floss. Minimum length of 10cm. 144

148. IMPLANT MAINTENANCE 145

149. Oral hygiene. Implant stability (evaluate mobility). Peri-implant tissue health. Crevicular probing depths. Bleeding. FACTORS TO BE EVALUATED DURING MAINTENANCE APPOINTMENT 146

150. Radiographic assessment (serial) : Crestal bone level - (expect 1.0mm marginal bone loss during first year postinsertion, 0.1mm per year anticipated thereafter). Proper torque on screw joint. Occlusion. Patient comfort and function. 147

151. Patient’s Role (Co-Therapist). Hygienist’s Role. Dentist’s clinical Role. HYGIENE PROTOCOL 148

152. Maintain plaque control. Use of interdental brush, hand brush and motorised brush. Use of floss. Use of chlorhexidine mouth wash. Depends on : Relative simplicity of procedure. Minimum number of devices. Time required for maintenance & care. ROLE OF PATIENT (CO-THERAPIST) 149

153. Check plaque control effectiveness. Check for inflammatory changes. If pathology is found - Probe with plastic probe. Scale supragingivally. Check for the problems of implant. HYGIENIST’S ROLE 150

154. Check patient every 3-4 months. Check plaque control effectiveness. Radiographic evaluation every year. Check for inflammatory changes & if pathology found probe with plastic probe. Check for the problems of implant. DENTIST’S CLINICAL ROLE 151

155. INSTRUMENTATION FOR IMPLANT HYGIENE MAINTENANCE 152 Super floss. End tufted brushes. Proxy brushes. Tartar control. Dentrifices. Mechanical instruments.

156. Super - Floss : Excellent for all types of implant restorations. Butler Post Care Floss: Aid Excellent for implant bars and fixed hybrid prostheses. 153

157. Proxy brushes : End tufted brushes : 154

158. Plastic Scalers : Appropriate for cleaning around standard abutments supporting implant bar substructures, hybrid prostheses and implant supported splinted restorations. Plastic scaler tips are also available for metal handle scalers. 155

159. Prophy paste: Prophy paste and a rubber cup on a prophy head / handpiece can be used to polish implant bars when removal is not indicated. 156

160. Chlorhexidine gluconate - 0.12% Neutral sodium flouride. Local drug delivery system : Minocycline Chlorhexidine gluconate - 0.12% CHEMOTHERAPEUTIC AGENTS 157

161. CLINICAL MAINTENENCE PROCEDURES 158 Examination of implant site. 1) Crown & soft tissue assessment 2) Radiographic examination 3) Mobility assessment Maintenance protocols.

162. 159 AKUT PROTOCOL - Lang Etal STAGE RESULT THERAPY Pocket Depth (PD) < 3mm No plaque or Bleeding No therapy A Pocket Depth (PD) < 3mm Plaque and/or Bleeding on probing Mechanical cleaning, Polishing, Oral hygienic instructions.

163. 160 STAGE RESULT THERAPY B Pocket Depth (PD) : 4-5 mm Radiographically no bone loss Mechanical cleaning, Polishing, Oral hygienic instructions & Anti-infective therapy (eg:CHX) C Pocket Depth (PD) > 5mm Radiographically no bone loss < 2mm Mechanical cleaning, Polishing, Microbiological test, Local & Systemic anti-infective therapy

164. 161 STAGE RESULT THERAPY D Pocket Depth (PD) > 5mm Radiographically no bone loss > 2mm Resective or Regenerative therapy.

165. 162 IMPLANT QUALITY SCALE - MAINTENANCE (2007) Group I (Optimal Health) Normal Maintenance. Group II (Satisfactory Health) Reduce stresses. Shorter intervals for hygiene appointments. Gingivoplasy. Yearly Radiographs.

166. Group III (Compromised Health) Drug therapy. Antibiotics. Chlorhexidine. Surgical reentry. Revision surgery. Change in prosthesis or implants. Group IV (Clinical failure) Removal of implant. 163

167. Group V (Absolute failure) Bone Graft. 164

168. CONCLUSION 165

169. Failure of implant has a multi-factorial dimension. Often many factors come together to cause the ultimate failure of the implant. One needs to identify the cause not just to treat the present condition but also as a learning experience for future treatments. Proper data collection, patient feedback, and accurate diagnostic tool will help point out the reason for failure. An early intervention is always possible if regular check-up are undertaken. 166

170. As someone well said, it is not how much success we obtain, but how best we tackle complex situations and failures, that determine the skill of a clinician. No, doubt, failures are stepping stones to success but not until their etiologies are established and their occurrence is prevented. 167

171. REFERENCES 168

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174. Elkhaweldi A, Rincon Soler C, Cayarga R, Suzuki T, Kaufman Z. Various Techniques to Increase Keratinized Tissue for Implant Supported Overdentures: Retrospective Case Series. Int J Dent. 2015;2015:104903. Upadhyay, Amrita & Chamadia, Amyn & Bashir, Ruquaya. (2022). Cause of Implant complication and management. Albrektsson T, Zarb G, Worthington P, Eriksson AR. The long-term efficacy of currently used dental implants: a review and proposed criteria of success. Int J Oral Maxillofac Implants. 1986 Summer;1(1):11-25. PMID: 3527955. 171

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176. THANK YOU 173