Esthetic and functional outcomes of narrow-diameter implants compared in a cohort study to standard diameter implants in the anterior zone of the maxilla

The aim of this study was to evaluate functional and esthetic clinical outcomes and patient satisfaction with narrow-diameter implants in comparison to standard-diameter implants in the anterior zone of the maxilla in a follow-up examination after 1 to 6 years. The study was designed as a retrospective cohort study investigation including 27 patients receiving a 3.3-mm diameter single implant (NDI, n = 14) or a standard-diameter 4.1-mm single implant in the anterior zone of the maxilla (SDI, n = 16). Descriptive and analytical statistics were performed comparing both groups with regard to clinical examination including esthetic outcome, sulcus fluid flow-rate, crown esthetics, patients' satisfaction on visual analog scales, occurrence of biological or technical complication, probing pocket depths (Fisher exact test), pink esthetic score (PES) and Periotest (Mann-Whitney U-test). The level of significance was set at alpha = .05. The mean observation period was 4.8 years after crown insertion in the NDI group, and 4.9 years in the SDI group. Significant differences were observed for Periotest values in favor of the 4.1-mm implants (P = .014). No differences were found with regards to esthetics (PES; P = .27) or sulcus fluid flowrate (P = 0.73) and probing pocket depths (P = .35). Overall patient satisfaction was high for both groups with visual analog scale scores of 9.3 +/- 1.1 for NDI and 9.4 +/- 1.0 for SDI (P = .39). Clinical outcome with narrow -diameter implants was comparable to standard-diameter implants in the anterior zone of the maxilla with similar esthetic assessments and patients' satisfaction.