Purpose: This clinical study was conducted to compare the influence of a platform-switched bone-level implant and a platform-matched tissue-level implant on marginal bone loss during the first year after loading.

Materials and methods: Edentulous subjects who applied for two-implant-retained mandibular overdentures and showing sufficient bone volume for implants with 4.3-mm diameter and 12-mm length were enrolled. For standardization reasons, all subjects received a platform-matched tissue-level implant and a platform-switched bone-level implant in the anterior mandible. Since implants from the same manufacturer were used, both implants had identical implant thread designs and surface properties. All subjects received two-implant-retained mandibular overdentures with opposing maxillary complete dentures, and the implants were loaded after 6 weeks. Marginal bone loss was monitored via panoramic radiographs obtained immediately after loading and at the 6- and 12-month recalls after implant loading, and periodontal parameters, such as pocket probing depths, Plaque Index scores, and bleeding on probing, were also measured and recorded.

Results: Twenty-six patients received 26 bone-level and 26 tissue-level implants. No statistically significant differences were detected between the bone loss of the two groups for all the measurements (P > .05). Additionally, no significant difference was detected between the measured periodontal parameters of the two groups (P > .05).

Conclusion: Within the limitations of this prospective clinical study with a follow-up time of 12 months, it can be concluded that the platform-switching bone-level design and the platform-matching tissue-level design show similar bone loss in the anterior edentulous mandible.