Clinical Performance of Short Dental Implants Supporting Single Crown Restoration in the Molar-Premolar Region: Cement Versus Screw Retention

Purpose: This study assessed the survival and marginal bone loss of single-unit short implants (≤ 8 mm in length) in the premolar-molar area. It also compared cemented with screw-retained restorations. Materials and Methods: In this clinical retrospective study, short implants supporting a single crown in the premolarmolar region were selected. Demographic-, surgical-, implant-, and prosthesis-related data were obtained. The predictor variable was the type of prosthesis retention. The principal variables were survival rate and marginal bone loss. The secondary variables were prosthesis survival and technical and biologic complications. Results: A total of 113 patients (56 ± 11 years of age) with 128 short implants were assessed. The mean follow-up time from implant insertion was 25.47 ± 14.95 months. Fifty-one crowns were cemented and 77 were screw-retained. No failure events were recorded for the implants and the prostheses. The distal marginal bone loss was significantly lower in the screw-retained crowns than in the cemented crowns. Marginal bone loss ≥ 2 mm as a biologic complication was more frequent in the cemented crowns. Two screw-loosening events were observed in the screw-retained restorations. These events were resolved by screw retightening. Conclusion: Short implants could be an effective option to support a single-unit prosthesis in the premolar-molar areas of the maxillae. Keywords: cement, crown, screw, screw-retained, short dental implants, single-unit