Application and limitations of configuration factor (C-factor) in stress analysis of dental restorations

Objective: The configuration factor (C-factor) is an index used to evaluate the relationship between cavity configuration and the development of polymerization shrinkage stress in dental restorations. Although C-factor has been widely researched, its correlation with stress analysis in dental restorations remains controversial. This review aims to discuss the application and limitations of C-factor and define the restricted conditions under which the C-factor rule of thumb is applicable. Methods: A thorough literature review was conducted on the application and limitations of C-factor in stress analysis of dental restorations. This was principally based on MEDLINE/PubMed and Web of Science databases and a review of the relevant studies and publications in scientific papers in international peer-reviewed journals for the specific topic of C-factor and polymerization shrinkage. Results: The C-factor alone cannot provide an accurate prediction of the shrinkage stress of restorations and the mechanical behavior of material-tooth interfaces. C-factor is only applicable under one condition not typically seen in clinical practice: low, near-rigid compliance. Significance: Conditions for the application of C-factor have been explicitly defined. A more accurate and precise understanding and utilization of the C-factor is of benefit as it contributes to better understanding of polymerization shrinkage behavior of restorations.

Automated summary

C-factor is an index used to evaluate the relationship between cavity configuration and the development of polymerization shrinkage stress in dental restorations. However, its correlation with stress analysis remains controversial. C-factor is only applicable under low-rigid compliance and cannot accurately predict the shrinkage stress of restorations and the mechanical behavior of material-tooth interfaces.