Purpose: The aims of this study were: (1) to quantify the marginal bone loss (MBL) of 3.3-mm narrow-diameter, bonelevel, titanium-zirconia (Ti-Zr) implants with two different surfaces in single restorations after a 1-year follow-up; (2) to analyze the combinations of different variables that may influence MBL; and (3) to record the Pink Esthetic Score (PES) value and its correlation with MBL.

Materials and methods: This is a prospective longitudinal clinical study with a 1-year follow-up after crown placement. Two different implant surfaces (sandblasted acid-etched and modified sandblasted acid-etched) were used. All bone-level and bone level-tapered implants had a diameter of 3.3 mm. Different healing and prosthetic abutments were used. Clinical, radiographic, and photographic records were taken 6 months and 1 year after placement of the restorations, and the survival rate, MBL, PES, clinical parameters, and biologic and/or mechanical complications were assessed. The correlations between the variables and MBL were verified.

Results: A total of 30 narrowdiameter implants were placed in 30 patients; 18 implants had a sandblasted acid-etched surface, and 12 implants had a modified sandblasted acid-etched surface. The measured MBL at 1 year after implant function had a mean value of -0.36 mm, ranging from 0 mm to -1.77 mm. There was no implant loss. A statistically significant relationship was observed between implant shape (design and length), implant placement level, healing abutment, prosthetic abutment size, gingival thickness, and MBL. The mean PES values recorded at the beginning and end of the study were 7.58 and 11.37, respectively.

Conclusion: Narrow-diameter implants showed reduced MBL values, with the surrounding tissues remaining stable after 1 year of follow-up. The MBL did not show different values on two implant surfaces. MBL does not seem to influence esthetic outcome.