Study design
STM, dehiscence
DEHISCENCE, PLAQUE
The present randomized controlled clinical trial was approved by the local ethics committee (Kantonale Ethikkommission Kanton Zürich, Ref. Nr. KEK-ZH-Nr. 2013–0121) and was performed following the principles outlined in the World's Medical Association's Declaration of Helsinki on experimentation involving human subjects (“World Medical Association Declaration of Helsinki: ethical principles for medical research involving human subjects.”, 2013).Sixty-four patients were consecutively enrolled at the Clinic of Reconstructive Dentistry, University of Zurich, Switzerland, after signing the informed consent. All treated patients were in need of dental implant therapy with fixed dental restorations. Using a computer-generated randomization, enrolled patients were randomly assigned to receive dental implants from either one of two manufacturers: AST (OsseoSpeed TX 3.0–5.0 S, TX 4.5; Astra Tech Implant System, Dentsply Sirona) or STM (Straumann Bone Level Implants 3.3, 4.1, 4.8 mm, SLAactive; Straumann AG). The inclusion and exclusion criteria, the specific surgical procedure as well as the prosthetic protocol, were already reported in previously published literature [In summary, enrolled patients were healthy and of legal age, showed neither local oral nor systemic pathologies, performed good oral hygiene (full mouth plaque control record < 25% [The surgical procedures followed the manufacturers’ recommendations as well as the standard protocol of the clinic. A standardization of the vertical implant position was not pursued, given the necessity to account for influential factors such as mucosal thickness and the prosthetic restoration design. This approach acknowledges the individualized nature of implant placement, where optimizing the vertical position requires careful consideration of these variables. Implants requiring a guided bone regeneration (GBR), in cases of a dehiscence or a fenestration defect, were grafted with demineralized bovine bone mineral (DBBM) (Bio-Oss Spongiosa; Geistlich Pharma AG) and a resorbable (Bio-Gide, Geistlich Pharma AG) or a non-resorbable (Gore-Tex; W.L. Gore & Assoc.) membrane to cover the bone substitute. Depending on the surgeon’s preference and the clinical situation, in some cases synthetic bone grafting materials were applied.The prosthetic treatments were performed according to the guidelines of the respective implant systems. Implant restorations were screw-retained or cemented based on the clinical situation and the clinician’s preference.Baseline was defined as the timepoint of the insertion of the final restoration. The maintenance care with a regular recall including dental hygiene sessions was personalized for every patient at the baseline appointment. Follow-up examinations were scheduled at 1, 3, 5, 8 and 10 years after baseline. This article is reported in compliance with the according CONSORT guidelines for the examination of parallel group randomized trials.The primary outcome of the study was marginal bone level changes. Secondary outcomes were implant and restoration survival rates, clinical, biological and technical outcomes.