Frequency and Patterns of Inappropriate Maxillary Incisor Abutment Preparation for Metal-Ceramic Retainers in Fixed Dental Prostheses: A Cross-Sectional Study
DOI:
https://doi.org/10.52206/jsmc.2025.15.4.1326Abstract
Background: The maxillary central incisor is a common abutment for metal-ceramic fixed dental prostheses (MC-FDPs). Successful outcomes require precise tooth preparation, but clinical practices often deviate from recommended guidelines, potentially compromising function, esthetics, and longevity of the prosthesis. Limited local data exist on the prevalence and types of inappropriate tooth preparation.
Objective: To determine the frequency and patterns of inappropriate preparation of maxillary central incisor abutments for metal-ceramic retainers in fixed dental prostheses.
Methodology: This descriptive cross-sectional study was conducted in the Department of Prosthodontics, Saidu College of Dentistry, Swat, from January to May 2025. A total of 174 adult patients requiring fixed prostheses were included using consecutive sampling. Inclusion criteria were sound or restored maxillary central incisors with Class I occlusion. Exclusion criteria included malaligned teeth, periodontal pathology, post-retained crowns, or defective casts. Preparations were evaluated using visual inspection and standard measuring tools (vernier calipers and dividers) for adequacy of incisal, labial, palatal, and proximal reductions, finish line design, and axial convergence. All procedures were supervised by an experienced prosthodontist.
Results: The mean age of participants was 34.5 ± 12.27 years, with 55.7% males and 44.3% females. Inappropriate preparations were observed on proximal (48.9%), labial (40.8%), palatal (39.1%), and incisal (38.5%) surfaces. Improper finish lines (78.2%) and inappropriate axial convergence angles (65.5%) were highly prevalent. First-year residents consistently showed higher rates of error compared to second-year residents, but differences were not statistically significant (p > 0.05).
Conclusion: Despite established preparation guidelines, a majority of abutments demonstrated one or more inappropriate features, especially in finish line placement and axial convergence. These findings emphasize the need for enhanced clinical training and stricter adherence to preparation standards among dental trainees.
Keywords: Abutment, Fixed dental prosthesis, Metal-ceramic crown, Prosthodontics, Tooth preparation.
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