Prefabricated Versus Customized Abutments: A Retrospective Analysis of Loosening of Cement-Retained Fixed Implant-Supported Reconstructions.
OBJECTIVE
The aim of this retrospective follow-up study was to determine whether implant-supported reconstructions on customized computer-milled abutments will loosen less frequently than those placed on prefabricated abutments.


METHODS
Suprastructures on prefabricated abutments (n = 312) were compared with those on customized computer-milled abutments (n = 96) over an observation period of 2 years. In all cases, the suprastructures had been cemented on the abutments with zinc oxide-eugenol cement (ZEC). Both groups were subdivided into single-crown restorations, fixed dental prostheses (FDPs) with two implants, and FDPs with more than two implants. The data were evaluated on the denture level.


RESULTS
Of the restorations on prefabricated abutments, 8% loosened, and of those on customized abutments, 3.1% loosened. The difference was not significant. Of the single crowns on prefabricated abutments, 7.7% loosened, and of those on customized abutments, 0% loosened. The difference was significant. For the FDPs with two implants (prefabricated abutments: 9.7%; customized abutments: 10.7%; not significant) and the FDPs with more than two implants (prefabricated abutments: 0%; customized abutments: 11.1%; significance not analyzed), statistical evaluation was difficult because of the small number of cases.


CONCLUSIONS
Loosening of reconstructions placed on customized abutments can be reduced for single-crown restorations. When ZEC is used, customized abutments offer a valid alternative to prefabricated abutments. The small number of cases of FDPs with two implants and FDPs with more than two implants made statistical evaluation impossible.
Michael
M
Korsch
Winfried
W
Walther
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002484:Cementation / Q000379:methods*; D017076:Computer-Aided Design; D003442:Crowns; D000044:Dental Abutments; D059605:Dental Implant-Abutment Design; D019094:Dental Prosthesis, Implant-Supported; D019232:Dental Restoration Failure; D003830:Denture, Partial, Fixed; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D055815:Young Adult; D015035:Zinc Oxide-Eugenol Cement / Q000737:chemistry
D015035:Zinc Oxide-Eugenol Cement