Comparison in Four Different Implant Systems of Mechanical Resistance to Maximal Stress in Prosthetic Screws-An In Vitro Study

Micromovements of the implant-abutment connection influence peri-implant bone preservation. This study evaluates and quantifies the maximal torque after a cycle of implant prosthetic screws tightening using original components. A total of 40 samples were tested: Megagen^®-Daegu, South Korea; Dentium^®-Gangnam-Gu, Seoul, Korea; BIOMET 3i^®-West Palm Beach, FL, USA and BTI^®-Álava, Spain. Screws from each manufacturer were subjected to maximal stress force until they fractured. The fracture points were recorded and compared among all samples. To compare the mean values of fracture torques, the reference values associated with each brand and the sample results were used in t-tests. ANOVA (analysis of variance) was used to compare the maximal resistance limit between brands, complemented with Tukey's multiple-comparison test. The maximal considered level of significance was 5%. The average fracture force for the brands was 40.07 Ncm for Megagen^®, 53.39 Ncm for Dentium^®, 39.74 Ncm for Biomet 3i^®, and 68.84 Ncm for BTI^®. BTI^® screws showed the most resistance to fracture. According to the protocol that was applied, the implant-abutment connection demonstrated good resistance and a precise fit between these interfaces; therefore, in some cases, the presented values showed a lack of quality control and low fracture resistance.