Efficiency and geometric fidelity of library-selected anatomical prefabricated abutments and stock abutments relative to custom CAD-CAM abutments in posterior implant restorations.

PURPOSE: This study evaluated the clinical efficiency and geometric fidelity of the library-selected anatomical prefabricated abutments (LAPA) compared with custom abutments (CA) and stock abutments (SA) by using a novel sector-based deviation analysis (SBDA) method. MATERIALS AND METHODS: Two posterior single-implant cases, the mandibular left first molar and right second premolar, were selected for in vitro analysis. Twenty-four dental professionals (15 prosthodontic residents and 9 board-certified prosthodontists) performed three tasks: CA design, LAPA selection, and SA selection. The recorded time required for CA design and LAPA selection was compared. Overall geometric conformity was assessed using in-tolerance analysis (± 0.50 mm, ± 0.70 mm), and margin-level fidelity was evaluated by sector-based and vector-based deviation analyses. The Wilcoxon signed-rank test was used to evaluate the clinical efficiency and geometric fidelity at a significance level of α = 0.05. RESULTS: LAPA required significantly less design time than the custom abutment (CA) (P < .001). Both LAPA and SA showed high overall conformity to CA within clinically acceptable limits. Sector- and vector-based analyses demonstrated that LAPA more closely replicated CA margin positions than SA, indicating superior morphological consistency with greater time efficiency. CONCLUSION: Within the limitations of this in vitro study, the library-selected anatomical prefabricated abutment showed a balanced performance between clinical efficiency and morphological fidelity.