Long-term outcome of cemented versus screw-retained implant-supported partial restorations.
OBJECTIVE
The present study was designed to compare the long-term outcome and complications of cemented versus screw-retained implant restorations in partially edentulous patients.


METHODS
Consecutive patients with bilateral partial posterior edentulism comprised the study group. Implants were placed, and cemented or screw-retained restorations were randomly assigned to the patients in a split-mouth design. Follow-up (up to 15 years) examinations were performed every 6 months in the first year and every 12 months in subsequent years. The following parameters were evaluated and recorded at each recall appointment: ceramic fracture, abutment screw loosening, metal frame fracture, Gingival Index, and marginal bone loss.


RESULTS
Thirty-eight patients were treated with 221 implants to support partial prostheses. No implants during the follow-up period (mean follow-up, 66 ± 47 months for screw-retained restorations [range, 18 to 180 months] and 61 ± 40 months for cemented restorations [range, 18 to 159 months]). Ceramic fracture occurred significantly more frequently (P < .001) in screw-retained (38% ± 0.3%) than in cemented (4% ± 0.1%) restorations. Abutment screw loosening occurred statistically significantly more often (P = .001) in screw-retained (32% ± 0.3%) than in cement-retained (9% ± 0.2%) restorations. There were no metal frame fractures in either type of restoration. The mean Gingival Index scores were statistically significantly higher (P < .001) for screw-retained (0.48 ± 0.5) than for cemented (0.09 ± 0.3) restorations. The mean marginal bone loss was statistically significantly higher (P < .001) for screw-retained (1.4 ± 0.6 mm) than for cemented (0.69 ± 0.5 mm) restorations.


CONCLUSIONS
The long-term outcome of cemented implant-supported restorations was superior to that of screw-retained restorations, both clinically and biologically.
Department of Oral Rehabilitation, The Maurice and Gabriela Goldschleger Scool of Dental Medicine, Tel-Aviv University, Tel-Aviv, Israel. nissandr@post.tau.ac.il
Joseph
J
Nissan
Demitri
D
Narobai
Ora
O
Gross
Oded
O
Ghelfan
Gavriel
G
Chaushu
D000328:Adult; D000368:Aged; D016301:Alveolar Bone Loss / Q000145:classification / Q000209:etiology; D002484:Cementation / Q000379:methods*; D003442:Crowns; D000044:Dental Abutments; D003761:Dental Impression Technique; D003776:Dental Porcelain / Q000737:chemistry; D019094:Dental Prosthesis, Implant-Supported; D019232:Dental Restoration Failure; D003781:Denture Retention / Q000295:instrumentation* / Q000379:methods; D003830:Denture, Partial, Fixed; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007576:Jaw, Edentulous, Partially / Q000534:rehabilitation; D008137:Longitudinal Studies; D008297:Male; D016876:Metal Ceramic Alloys / Q000737:chemistry; D008875:Middle Aged; D010512:Periodontal Index; D016300:Radiography, Bitewing; D016896:Treatment Outcome
D016876:Metal Ceramic Alloys; D003776:Dental Porcelain