A systematic review of screw- versus cement-retained implant-supported fixed restorations.

PURPOSE: To systematically evaluate the survival and success of screw- versus cement-retained implant crowns. MATERIALS AND METHODS: The authors performed an electronic search of nine databases using identical MeSH phrases. Systematic evaluation and data extraction of the articles from 1966 through 2007 were completed by three reviewers and two clinical academicians. The major outcome variable was implant or crown loss, and the minor outcome variables were screw loosening, decementation, and porcelain fracture. Random effects Poisson models were used to analyze the failure and complication rates. RESULTS: The initial search produced 26,582 articles. Of these, 577 titles and subsequently 295 abstracts were available for evaluation, with 81 full texts meeting the criteria for review. Data were extracted from 23 level one and two research studies. Fleiss' kappa interevaluator agreement ranged from almost perfect to moderate. Major failures included 0.71 screw-retained and 0.87 cement-retained failures per 100 years. Minor failures included 3.66 screw loosenings, 2.54 decementations, and 0.46 porcelain fractures per 100 years. CONCLUSION: There is no significant difference between cement- and screw-retained restorations for major and minor outcomes with regard to implant survival or crown loss. This is important data, as clinicians use both methods of restoration, and neither is a form of inferior care.

Clinician- and patient-reported long-term evaluation of screw- and cement-retained implant restorations: a 5-year prospective study.

The purpose of this study was to evaluate the survival and success of screw- versus cement-retained implant crowns over a 5-year period. This was a multi-center prospective cohort study, consisting of patients who had ≥1 dental implant placed and restored in the anterior maxilla over a 5-year period. The primary predictor variable was the type of restoration (screw- versus cement-retained). The outcome variables were clinician- or patient-reported measures related to soft tissue and restoration quality. Descriptive and bivariate statistics were computed to compare the screw- versus cement-retained groups. Kaplan-Meier statistics were computed for implant survival. Information was collected for 102 patients who had 214 implants placed during the study period. Complete data, amenable to analysis, were available for 99 (97.1%) patients and 193 (90.2%) implants. The restorations were approximately evenly divided between screw- (53.4%) and cement-retained (46.6%). Approximately 49% of patients in the sample were female; the sample's mean age was 47.3 ± 13.9 years; each patient had an average of 2.0 ± 1.0 implants placed and restored. The mean time from prosthesis placement (definitive) to study endpoint was 61.9 ± 10.6 months. The overall implant survival rate was 96.4%, with no statistically significant difference in survival between the screw- and cement-retained groups (p = 0.45). The majority of clinician- and patient-assessed outcomes were similar. The results of this study indicate that for the majority of clinician- and patient-assessed success parameters screw- and cement-retained restorations are equivalent in the anterior maxilla.