Efeito de parâmetros geométricos biomecânicos sobre a remodelação óssea peri-implantar em próteses totais fixas implantossuportadas

Abstract

Implant-supported fixed complete dentures (PTFI) present failures and complications over time. Thus, understanding the risk factors is necessary to develop strategies to reduce them. This prospective study aimed to evaluate the effect of PTFI geometric biomechanical parameters on perimplant bone remodeling up to one year of function. The sample consisted of images of computerized tomographic exams of 48 PTFI with metallic infrastructure and acrylic resin coat in edentulous maxilla and mandible (21 e 27 respectively), totaling 246 external hexagon implants. DICOM-format images were processed to measure: supporting polygon area, clinical crown/implant ratio (vertical lever), antero-posterior power and resistance arms, of anterior cantilever and posterior cantilever distances (horizontal levers) and perimplant bone remodeling (outcome measure). Data were analyzed by descriptive statistics and multilevel multivariable models. The results exhibited average bone loss, in one year of function, correspond to 0.88mm (0,82 ± 0,94). As for the arch, the results showed average bone loss of 0,62mm (0,57 ± 0,67) and 1,08mm (0,98 ± 1,18) in mandible and maxilla, respectively. The clinical crown/implant ratio (vertical lever) and anterior cantilever (power arm of the anterior horizontal lever) had a significant effect on perimplant bone loss, according to the implant position in the arch and measuring face. It can be concluded that perimplant bone loss increases with the vertical lever (crown / clinical implant ratio) and that the anterior cantilever has a protective effect at the lingual face in anterior implants. Under the biomechanical perspective, these variables should be considered when planning and executing PTFI.