Abstract
This study investigated the effect of three abutment screw manufacturing methods and modifications in the internal threading process of dental implants on screw loosening. A total of 30 screws were produced, with 10 screws for each manufacturing method. Additionally, 30 dental implants were fabricated and categorized based on their internal threading technique: 15 implants used a cutting tap, referred to as cutting implants (C), and 15 implants used a forming tap, referred to as formed implants (F). Each group of the screws was divided into 2 subsets: one subset was paired with C implants, and the other was paired with F implants. Subsequently, torque loss for each screw was measured before and after a vibration test using a digital torque meter, and a one-way ANOVA and an independent samples t-test (α = 0.05) were used to investigate the significance level of the difference in screw loosening between manufacturing methods. The study found that machined, thread-rolled, and die screws exhibited an average total torque loss of 3.51%, 5.13%, and 7.52% when paired with C implants, and 2.42%, 4.33%, and 6.27% when paired with F implants, respectively. Statistically, the one-way ANOVA and the independent samples t-test revealed a significant effect of the abutment screw type on the total torque loss (P < .05). Moreover, the implant type had a significant effect on the torque loss values before and after the vibration test (P < .05). These findings suggest that screw manufacturing method and internal threading modifications are critical factors in enhancing the mechanical stability of implant components.