The effect of implant size 5 × 8 mm on crestal bone levels around single-tooth implants

There is substantial evidence supporting the strain-induced biologic response of bone to mechanical load. Stress-related factors, such as implant size, have been associated with changes in crestal bone levels on dental implants. The purpose of this study is to evaluate the effect of an implant size, specifically 5 mm wide × 8 mm long (5 × 8), on peri-implant bone levels.

A retrospective cohort study was conducted. The cohort was composed of patients who had ≥1 plateau root-form implant. Descriptive statistics, univariate and multivariate mixed-effects regression models, adjusted for multiple implants in the same patient were used to evaluate the correlation between 5 × 8 implants and other clinically relevant factors on crestal bone levels after insertion of single-tooth replacements.

The cohort was composed of 81 individuals who received 326 implants. The average change in crestal bone levels (AvBL) for 5 × 8 maxillary and mandibular implants after 5.9 years of follow-up were -0.36 and -0.04 mm, respectively. In contrast, AvBL for mandibular implants not measuring 5 × 8 was -0.51 mm. Of several different local and systemic factors evaluated, including 10 different implant sizes, 5 × 8 mandibular implants were found to be significantly less likely to lose bone when compared with mandibular implants not measuring 5 × 8 (P = 0.047).

Implants measuring 5 × 8 demonstrated statistically significantly less peri-implant bone loss in the posterior mandible. This finding indicated that a specific implant size may be involved in mandibular bone preservation. However, prospective multicenter clinical trials are needed to validate these findings.