Severity and prevalence of spantaneous early exposure of dental implant cover screw and factors affecting it

Abstract

Spontaneous early cover screw exposure between stage I and II of two-stage method of implant surgery is a common problem that can disrupt the initial repair and osteointegration process by distroying sterile conditions. The aim of this study was to investigate the prevalence of spontaneous exposure cover screw and identify its risk factors. Methods and Materials: The present study is a retrospective descriptive analytical study. In 40 patients with a total of 182 implants, in the second stage of surgery, data related to patient-related and implant-related variables were collected and all samples were examined for cover screw exposure according to Tal classification. The overall prevalence of the exposure was calculated and the effect of the variables on the cover screw exposure was statistically analyzed at the two-variable level and then at the multivariate level with SPSS software. Results: Out of 40 patients studied, 9 (22.5%) and out of 182 implants, 17 implants (9.3%) were exposed to the oral environment. Implant exposure was significantly associated with the variables of implant location (OR = 7.2, p = 0.027), mucosal thickness (OR = 13.5), p = 0.000) and implant placement time interval (p = 0.007, OR = 17.2). Conclusion: Despite the limitations of this retrospective study, a statistically significant relationship was found between the spontaneous cover screw exposure with a mocusal thickness of less than 2 mm, the placement of the implant as a fresh socket and the implants of the maxillary premolars.