Salomão Rocha

Platform switch versus platform match in the posterior mandible – 1-year results of a multicentre randomized clinical trial.

Objective The purpose of this ongoing randomized study was to assess differences in bone level changes and success rates using implants supporting single crowns in the posterior mandible either with platform matched or platform switched abutments. Material and Methods Patients aged 18 and above, missing at least two teeth in the posterior mandible and with a natural tooth mesial to the most proximal implant site were enrolled. Randomization followed implant placement. Definitive restorations were placed after a minimum transgingival healing period of 8 weeks. Changes in crestal bone level from surgery and loading (baseline) to 12-month post-loading were radiographically measured. Implant survival and success were determined. Results Sixty-eight patients received 74 implants in the platform switching group and 72 in the other one. The difference of mean marginal bone level change from surgery to 12 months was significant between groups (p < 0.004). Radiographical mean bone gain or no bone loss from loading was noted for 67.1% of the platform switching and 49.2% of the platform matching implants. Implant success rates were 97.3% and 100%, respectively. Conclusions Within the same implant system the platform switching concept showed a positive effect on marginal bone levels when compared with restorations with platform matching.

Effect of platform switching on crestal bone levels around implants in the posterior mandible: 3 years results from a multicentre randomized clinical trial

Abstract Objective Evaluation of differences in the clinical performance and crestal bone levels between implants restored with single crowns with platform‐matched or platform‐switched abutments after 3 years. Material and Methods The study enrolled adult patients missing two or more adjacent teeth in the posterior mandible with natural teeth mesial to the implant site. Randomization followed open‐flap implant insertion and the corresponding matching or switching healing abutments placed at surgery. Conventional loading was made with cemented crowns. Clinical follow‐up took place annually after loading up to 3 years. Bone level changes were measured in standardized radiographs as the variation in crestal bone from one evaluation to the next. Results Sixty‐three patients with a total of 135 implants (66 platform matching, 69 platform switching) were analysed. From surgery to 36 months, mean bone loss was 0.28 ± 0.56 mm for the platform‐switching group and 0.68 ± 0.64 mm for the platform‐matching group. A statistically significant difference was found between groups (p = 0.002) with an estimate of 0.39 mm (0.15–0.64, 95% CI) in favour of platform switching. Conclusions After 3 years, platform‐switching restorations showed a significant effect in the preservation of marginal bone levels compared to platform‐matching restorations.

Radiographic evaluation of conical tapered platform-switched implants in the posterior mandible: 1-year results of a two-center prospective study

Abstract Objective Long‐term success of dental implants depends on healthy peri‐implant soft tissues and adequate bone levels. This prospective study aims to assess bone level changes around implants with internal conical connection and platform‐switching abutments in the posterior mandible. Material and methods Adult patients missing at least two teeth in the posterior mandible and with a natural tooth mesial to the implant site received two or three adjacent internal conical connection implants. After a minimum transmucosal healing period of 8 weeks, single crown restorations were cemented over platform‐switching abutments. Changes in marginal bone levels were measured in standardized periapical radiographs from surgery and loading (baseline) to 12 months post‐loading. Results Twenty‐four patients received 52 implants. Bone remodeling took place between surgery and loading (−0.53 ± 0.40 mm). From loading to 12 months, there was a mean bone gain of 0.12 ± 0.42 mm which occurred mainly in the first 6 months after prosthesis delivery (0.11 ± 0.36 mm) and stabilized afterward. A total of 71.7% of all implants presented bone preservation or gain. No implant was lost at 1 year and the success rate was 100%. Patient inquiry revealed high satisfaction. Conclusion Internal conical connection implants with platform‐switching abutments presented high success rate and enhancement or preservation of marginal bone levels after 1 year of loading.