Factors Related to Early Marginal Bone Loss in Dental Implants-A Multicentre Observational Clinical Study

This study evaluated the effect of clinical and patient-related factors on marginal bone loss. The sample was composed of individuals who were treated at two dental schools in southern Brazil. The variables evaluated were divided into individual (age, sex, diabetes, hypertension and antihypertensive use), and implant levels (arch, position, brand, protection, torque, time). After implant installation and following the second stage, periapical radiographs were obtained to measure the distance between the peri-implant bone crest and implant platform. Measurements were performed using ImageJ software. Data were analyzed using linear and Poisson multilevel regression. Fifty-eight patients with 113 implants were evaluated. The mean marginal bone loss was 0.45 +/- 0.48 mm. Considering the linear multivariate model, age, diabetes, torque and time between surgery and reopening were found to be significant (p < 0.05). In the dichotomous model (bone loss <0.2 mm and >= 0.2 mm), only high torques resulted in higher marginal bone loss (p = 0.033). Marginal bone loss occurred before the second surgical stage and was greater in implants with high torque. Torque below 20 N, reopening performed after six months, diabetic status and young age all resulted in higher marginal bone loss, but these values are probably not clinically significant. These variables must be better explored in future studies.