A COMPARATIVE STUDY TO ASSESS THE EFFICACY OF DIFFERENT METHODS FOR THE RETRIEVAL OF FRACTURED IMPLANT ABUTMENT SCREW: AN IN VITRO STUDY

Abstract

Introduction: Fractured implant abutment screws represent a significant mechanical complication in implant dentistry and can compromise prosthetic stability, implant longevity, and treatment outcomes. Retrieval of fractured screws is a technically demanding procedure that requires effective removal while preserving implant integrity. Several retrieval techniques have been proposed; however, evidence regarding the most efficient and reliable method remains limited. Aim: To comparatively assess the efficacy of different methods for retrieval of fractured implant abutment screws in an in vitro setting. Materials and Methods: A total of 108 implant specimens embedded in acrylic blocks were included in this in vitro experimental study and equally divided into three groups (n=36): Group I—Claw-Type Retrieval Kit, Group II—Reverse Drilling Retrieval Kit, and Group III—Conventional Hand Instrumentation. Fracture morphologies (ASF-1, ASF-2, and ASF-3) were equally distributed among all groups. Outcome variables evaluated included retrieval success rate, number of attempts required, retrieval time, and implant thread integrity following retrieval. Data were statistically analyzed using SPSS version 21.0. Chi-square test, one-way ANOVA, and Tukey post hoc analysis were applied, with p<0.05 considered statistically significant. Results: Overall retrieval success was achieved in 72.2% of specimens. Reverse Drilling and Conventional Instrumentation demonstrated higher retrieval success rates (75%) compared with Claw-Type retrieval (66.7%), although differences were not statistically significant. Reverse Drilling showed significantly greater procedural efficiency with a higher rate of single-attempt retrieval and the shortest mean retrieval time (10.31 ± 3.42 minutes) (p<0.001). No significant differences were observed regarding implant thread damage among the groups. Conclusion: Reverse Drilling demonstrated superior procedural efficiency with fewer retrieval attempts and shorter retrieval time while maintaining implant thread integrity, suggesting that it may represent a reliable and clinically effective technique for fractured implant abutment screw retrieval.