Influence of zirconia implant surface topography on first bone implant contact within a prospective cohort study.

Rohr, Nadja; Balmer, Marc; Jung, Ronald E; Kohal, Ralf J; Spies, Benedikt C; Hämmerle, Christoph H F; Fischer, Jens

BACKGROUND Although 5-year clinical data exist for different zirconia implants, no analysis has yet been performed focusing on how the surface topography of the implant affects clinical parameters. PURPOSE To analyze the influence of zirconia implant topography on first bone implant contact (fBIC). MATERIALS AND METHODS In a prospective two-center cohort investigation 63 zirconia implants were evaluated at implant placement, prosthetic delivery, 1, 3, and 5 years. The distance (DIB) between implant shoulder and fBIC was measured at each time point in periapical radiographs at mesial and distal sites. Two-way ANOVA/Bonferroni was used to analyze the effects of time and center (α < 0.05). RESULTS Between the centers, the mean DIB varied significantly at implant placement (Freiburg [FR]: 1.4 ± 0.6 mm; Zurich [ZH]: 0.8 ± 0.5 mm). Thereafter, no statistically significant difference in DIB was observed, neither between centers nor between time points (prosthetic delivery: FR: 1.9 ± 0.6 mm, ZH: 1.7 ± 0.8 mm; 1 year: FR: 1.8 ± 0.6 mm, ZH: 1.6 ± 0.8 mm; 3 years: FR: 1.9 ± 0.8 mm, ZH: 1.7 ± 0.8 mm; 5 years: FR: 1.9 ± 0.8 mm, ZH 1.8 ± 0.6 mm). The overall mean DIB at prosthetic delivery to 5 years of both centers (1.8 ± 0.7 mm) is located within the transition zone between the smooth neck and the moderately rough intraosseous part (1.6-2.0 mm from the implant shoulder). However, individual DIB values are ranging from 0.1 to 4.2 mm overlapping the transition zone. CONCLUSIONS The standard deviation of the DIB indicates that the fBIC establishes on moderately rough and smooth surfaces. Consequently, soft tissue adapts to both topographies as well.