Background: Dental implant abutment screw loosening is an increasingly common problem, as evidenced by multiple studies that have investigated its causes. The objective of this study was to compare the screw loosening torque values before and after cyclic loading and to determine whether they are affected by the CAD/CAM abutment manufacturing technique (machined or laser-sintered) and abutment angulation. Materials and Methods: Ninety implants were used and divided into two groups: 45 implants received machined abutments (group A) and 45 implants received laser-sintered abutments (group B). Each group was further divided into three subgroups, with 15 implants each, based on the abutment angulation involved (0°, 15° and 20°). The abutments were tightened to the torque recommended by the manufacturer, and the reverse torque value was measured before and after cyclic loading (300,000 cycles). Data analysis was performed using one-way ANOVA and Wilcoxon signed-rank tests. Results: Statistically significant differences were observed between the laser-sintered and machined groups (p < 0.01). Additionally, differences were observed between subgroups with different angulations for both machined (16.2 ± 1.75, 14.7 ± 1.74 and 13.4 ± 1.08 Ncm) and laser-sintered abutments (14.6 ± 1.25, 12.7 ± 1.2 and 11.1 ± 1.35 Ncm) (0°, 15° and 20°, respectively). Conclusions: The final screw loosening torque after cyclic loading was lower than the initial loosening torque. Both abutment angulation and the CAD/CAM manufacturing method exerted a statistically significant influence on the final loosening torque. The abutment angulation factor was estimated to have an influence of 34.5%, while the abutment manufacturing method was estimated to have an influence of 21%.

Objectives: To analyze the impact of implantoplasty on the mechanical resistance of dental implants, considering different implantoplasty designs and implant types. Methods: A systematic review was conducted in accordance with PRISMA guidelines. A search was performed in four databases: PubMed, Scopus, Web of Science, and Embase, along with a manual search for additional relevant studies. In vitro studies assessing the mechanical resistance of dental implants subjected to implantoplasty were included. A total of 136 studies were identified; after duplicate removal using Rayyan, and screening by title and abstract, 17 studies were ultimately selected after full-text assessment. Results: In vitro studies on external hexagon implants showed that fracture resistance in control groups ranged from 773.1 N to 1660 N for implants with a 4 mm diameter, and from 478.1 N to 1650 N after implantoplasty. For 3.5 mm diameter implants, values ranged from 548.8 N to 1276.1 N in control groups, and from 465.9 N to 1211.7 N after implantoplasty. In internal hexagon connections, fracture resistance after implantoplasty ranged between 321.7 N and 739 N. Conical connections exhibited a broader range of resistance values after implantoplasty, from 315.9 N to 2395.3 N. Conclusions: Implantoplasty reduces the mechanical strength of dental implants. Increased implantoplasty length correlates with decreased resistance, particularly affecting narrow implants. The prosthetic connection most affected by this procedure is the external hexagon, followed by the internal hexagon, with the conical connection being the most resistant.