Evaluation of initial stability with resonance frequency analysis (RFA) and crestal bone preservation in two types of dental implants

Background

The primary stability of dental implants is very important for prosthetic rehabilitation viability and of peri-implant tissues health, fundamental for the maintenance of clinical success. This was a prospective, controlled clinical study that evaluated initial stability with resonance frequency analysis (RFA) and marginal bone crest preservation in two types of dental implants.

Aim/Hypothesis

The aim of this research was to evaluate two types of dental implants, installed in the posterior mandible region, regarding primary stability, measured by resonance frequency analysis (RFA) and peri-implant bone preservation evaluated in standardized digital radiographs with software ImageJ.

Material and Methods

Twenty-four implants were installed in adjacent edentulous site in the posterior mandible regions, in 12 different patients. Each patient received a BLT SLActive 4.1 x 8 mm implant from the Straumann company and a Unitite 4.3 x 8.5 mm implant from the company SIN. Surgeries were performed according to the instrumentation protocol of each company. Patient with implants installed with initial anchorage below 30 NCm were excluded from the study. The resonance frequency analyses (RFA) were performed at the time of installation, 4, 6 and 8 weeks with the Osstell ISQ apparatus. The bone crest assessments were made in the immediate postoperative period, 4 and 8 weeks with standardized periapical radiographs and ImageJ software for linear measurements.

Results

It was observed that both implants obtained the same stability behavior in all the evaluated periods, and the ISQ values of the Straumann implants were statistically higher than SIN's in all evaluated stages. The same pattern of bone response was also found for the two implants. On the mesial surface, both implants had a statistically significant reduction in bone levels from the immediate postoperative week to the 8 week assessment, while in the distal part there was no statistical difference in crest bone height. A positive correlation between stability, measured on ISQ, and bone loss at the ridge on the fourth and eighth week in the Straumann implants was observed.

Conclusion and Clinical Implications

It was concluded that both implants present similar behavior regarding bone loss and stability in all evaluated periods and that the stability values, in ISQ, of the Straumann implants were superior to the SIN implant.