13- failures in fixed prosthesis.pptx sunumu için gerekli

dentistry

1. Failure of Crowns and Fixed Dental Prosthesis

2. FACTORS CAUSING FAILURE OF CROWNS AND BRIDGES COULD BE CLASSIFIED ACCORDING TO THE STAGE IN WHICH IT OCCURS AS FOLLOWS: CEM E NTATION

3. Failure of fixed p r ost h esis Biologic Failure Mecha n ical Failure Esthetic Failure M a inten a nce Failure Classification according to mechanism of failure

4. Patient complaint may be; Immediate Delayed

5. 1. 2. 3. 4. 5. 6. 7. Biological Failure

6. Excessive Pressure on soft tissues Retention of food on the occlusal surface Traumatic occlusion Torque Cervical hypersensitivity of the abutment Improper pontic/ Lack of auxiliary Premature contact Lack of parallism Over displacement ridge relationship escape grooves between abutments of gingival tissue during impression taking pontic Improper buccal Over extended pressing on the and lingual --- --- temporary ridge embrasures protection Over extension Over extended cervical margins of --- --- --- cervical margins of retainers or crowns restoration Faulty proximal --- --- --- Short or open contact cervical margins of restoration Improper labial or Cervical caries lingual contour of --- --- --- retainers or pontics Discomfort, Pain and Sensitivity

7. CARIES 1. 2. 3. 4. 5. 6.

8. PULP INJURY due to; Improper use of coolant. Over reduction leaving insufficient dentin protective barrier. pulp exposure. Improper or absence of temporary protection. Use of irritating luting agent. Recurrent caries under the restoration Low grade pulp irritation as a results of traumatic occlusion

9. PERIODONTAL BREAKDOWN periodontal breakdown may lead to loss of abutment Patient suffer from; Mobility of abutment Periodontal pocket formation Periodontal abscess Pain which prevent mastication at the side of restoration Bad odor and taste

10. Periodontal breakdown may be due to; Inadequate abutment teeth in long span bridge. Periodontally affected abutment teeth. Patient with poor oral hygiene. Poor marginal adaptation. Over or under contour of axial walls Extensively large connectors that restrict the cervical embrasure. Pontic with large contact area on edentulous ridge. Improper or absence of proximal contact causing food impaction and periodontal pocket formation. Irregular or rough cervical margin of prosthesis.

11. OCCLUSAL PROBLEMS Premature contact in centric and eccentric occlusion excessive tooth mobility.

12. TOOTH PERFORATION due to; Faulty preparation. Or during post space preparation.

13. TOOTH FRACTURE 1- Coronal tooth fracture Due to; Over reduction of abutment Recurrent caries Un-retained restoration Presence of premature contact or heavy occlusal force Application of excessive force during seating of improperly fitting restoration Incorrect removal of cemented restoration

14. 2- Root fracture Due to; Excessive widening of root canal during endodontic treatment or during post space preparation Forceful seating of post Caries extended to root surface Trauma

15. MECHANICAL FAILURE Cementation failure; looseness and/or dislodgment of restoration, it could be due to Cement failure Retention failure Occlusal problems Different degree of abutments mobility Restoration failure ( retainer, pontic, or connector ) Occlusal wear or perforation

16. 1- Cementation Failure a- Cement failure This could be due to; 1- Cement selection Expired cement Clinician not follow manufacturer’s instructions Incomplete removal of temporary cement 5- Inadequate isolation 6- Inclusion of cotton fibers 7- Incomplete isolation 8- Insufficient pressure seating

17. 1- Cementation Failure b- Retention failure This could be due to; 1- Excessive taper - Short clinical crown 3- Misfit 4- Misalignment

18. 1- Cementation Failure c- Occlusal problems This could be due to; occlusal interference Occlusal perforation Parafunctional activity Loss of occlusal contacts

19. 1- Cementation Failure d- Different degree of abutments mobility This induce stresses on the cement which lead to cementation failure

20. 2- Restoration Failure Retainer failure; Perforation Marginal discrepancy Veneering separation, fracture or wearing

21. b- Pontic failure; Pontic fracture (Porcelain) with unfavorable occlusal load Limited occlusocervical height due to over eruption

22. c- Connector failure;

23. This could be due to; 1- Improper designing of connector size and position 2- Thin metal at the connector 3- Incorrect selection of solder 4- Porosity

24. Occlusal wear or perforation Heavy chewing, clenching or Bruxism wear of restoration perforation of occlusal surface of the metal restoration Leakage, cement dissolution & caries

25. Esthetic Failure Improper shade matching Insufficient tooth reduction Dis h armo n y be t wee n res t orat i o n a n d n e ighb o ring teeth Improper masking of metal by esthetic material Us e o f i m prop e r s h ad e o f ce m en t wit h al l c era m ic restoration Unn e cess a r y d i spl a y o f meta l i n cas e o f p a rti a l veneer metal restoration Imp r ope r marg i na l adap t atio n , f o rm , r ough n ess , or extension which lead to gingival inflammation causing unnatural soft tissue color

26. Maintenance Failure Poor oral hygiene and improper maintenance of a well done restoration may lead to failure of prosthesis. The patient must be fully informed about his responsibility in success or failure of restoration The dentist must recall the patient for periodic clinical and radiographic examination to detect early any harmful changes that might occur.

27. Have a nice day !