The Association between the Frequency and Severity of Cover Screw Exposure in Dental Implants and Some Effective Factors

Background and Objective: Early exposure of the cover screw between two implant placement stages is a common problem that can impair the initial healing and success of the implant treatment. The aim of this study was to investigate the relationship between the frequency and severity of dental implant cover screw exposure and some effective factors. Methods: In this cross-sectional study, 159 implant units were examined in 35 patients who referred to Yazd Dental School for the second stage of implant placement in 2022-2023 after a 3-6-month initial healing period. Before the second stage, the area was examined for exposure severity based on Tal classification, and then the relationship between this event and the variables of gender, presence of systemic disease, keratinized gingiva width, thickness of the covering tissue on the buccal side, location and type of edentulism, time interval from extraction to replacement, and bone regeneration were examined. Findings: Of the 159 implants, 18 had spontaneous exposure. The most common exposure in terms of severity was class 4. There was a significant association between exposure and male gender (p=0.009), systemic disease (p=0.041), buccal overlying tissue thickness (3.00±1.17 vs. 0) (p<0.001), and keratinized gingiva width (2.16±1.03 vs. 2.82±1.30) (p=0.042). No significant association was found between exposure and other selected factors. Conclusion: The results of this study showed that the severity of cover screw exposure is related to factors such as systemic diseases, keratinized gingiva width, and buccal tissue thickness.