Assessment of the Effect of Clinical Independent Risk Factors on Marginal Bone Loss in 2-Implant–Supported Locator-Retained Mandibular Overdentures

The objective of this study is to evaluate the effect of clinical parameters of gender, age, implant length, implant diameter, interimplant distance, and locator height on marginal bone loss in 2-implant–supported locator-retained mandibular overdenture prostheses in 6, 12, and 24 recall sessions after loading. Clinical and radiographic data of patients who were treated between January 1, 2014, and January 4, 2018, were retrieved from the archives. The clinical data of gender, age, implant length, implant diameter, and locator height were recorded. The mesial and distal marginal bone levels of all implants and interimplant distances were determined at baseline and at 6-, 12-, and 24-month recall sessions on panoramic radiographs in a computer program. Statistical analysis was used to evaluate the effect of implant length, implant diameter, gender, age, interimplant distance, and locator height on marginal bone loss at the 6-, 12-, and 24-month control evaluations. A total of 57 patients with a mean age of 59.2 ± 9.8 years and 114 implants were included in the study. Among the aforementioned parameters, only the locator height had a major effect on the distal and mesial marginal bone loss (P < .05). A locators with a 4-mm height showed statistically significant distal and mesial marginal bone loss compared with locators with 2- and 3-mm heights in all control periods (P < .05). The locator with a 4-mm height generated more stress compared with locators with 2- and 3-mm heights, leading to marginal bone loss. The absence of oral hygiene evaluation was identified as a limitation of the study. Clinical parameters of gender, age, implant length, implant diameter, and interimplant distance did not seem to affect marginal bone loss in the study population of the current study.