Comportamento mecânico de soluções anguladas em prótese sobre implantes

: estudo piloto

Abstract

Introduction: Fixed prosthetic oral rehabilitation can be performed using dental retainers or, in their absence, using dental implants. The existence of anatomical and morphological limitations can prevent the implant from being placed in an ideal prosthetic position, making rehabilitation a challenge. Due to these limitations, several problems can arise, for example, the aesthetic compromise associated with the appearance of the screw access channel in visible areas. To overcome this situation, dynamic solutions with “angled screw channels” were developed, which allow access to the screw channel using a multiangular screwdriver. Materials and Methods: To test the mechanical behavior of 3 dynamic solutions (BHS30®, UBH30® 4 grooves, UBH30® 6 grooves) a laboratorial study was carried out, which was divided into two tests. In the first test, the samples of each system were tightened with the recommended torque of 30 N.cm, at 0º and 30º, and 10 and 30 tightening cycles were performed. It was also tested a Neodent® standard screw as a way of comparison. At the end of each interval of repetitions, the screw and the screwdriver were analyzed using laboratory loupes in order to analyze the presence of possible deformations and surface changes. In the second test, the same systems were submitted to a progressive torque until a fracture and/or deformation of one of the components occurred, in order to be able to determine the maximum torque value that they support. Later, they were also analyzed with laboratory loupes in order to characterize the failure. Results: Comparing the mean values of torque between the standard system used and the dynamic solutions, it wasn’t verified the existence of significant differences. Comparing the different dynamic systems, it was found that the UBH30® 4 grooves is the one with the highest average torque values, being also the only system that doesn’t show variations in torque values between 0º and 30º. BHS30® is the system that supports higher maximum torque values. Conclusion: Within the limitations of this experimental study, it seems that these dynamic solutions can be considered a viable option in implantology, as long as the biomechanical behavior of the materials is respected. However, further studies are needed to prove the clinical applicability and the long-term success of prosthetic rehabilitations.

Date of Award	23 Jul 2021
Original language	Portuguese
Awarding Institution	Universidade Católica Portuguesa
Supervisor	André Correia (Supervisor) & Filipe Miguel Araújo (Co-Supervisor)