Microbial Composition of Carious Dentin and the Impact of Minimally Invasive Excavation Techniques: A Narrative Review

Dental caries is a biofilm-mediated dysbiotic disease characterized by ecological shifts within the oral microbiome and progressive demineralization of dental hard tissues. The microbiological composition of carious dentin and the impact of minimally invasive excavation techniques on residual microbial communities remain subjects of ongoing investigation due to methodological heterogeneity and inconsistencies among published studies. This narrative review aimed to summarize current evidence regarding the microbial ecology of carious dentin, compare culture-based and molecular methods for microbiological assessment, and evaluate the microbiological outcomes associated with contemporary approaches to managing minimally invasive caries. The relevant literature on dentinal caries microbiology, microbial detection methods, and excavation techniques was analyzed. The available evidence indicates that carious dentin contains a highly diverse polymicrobial community composed of acidogenic, aciduric, anaerobic, and proteolytic microorganisms. Culture-based methods primarily detect viable and cultivable taxa, whereas molecular approaches reveal substantially greater microbial diversity, including uncultivable and low-abundance species. Comparative studies demonstrate that minimally invasive excavation techniques significantly reduce microbial load but rarely achieve complete microbial elimination. The available evidence suggests that successful caries management is associated with a reduction in and ecological modulation of the residual microbiota within a sealed environment. The integration of culture-based and molecular findings provides a more comprehensive understanding of the microbiology of carious dentin and supports biologically oriented, minimally invasive strategies for caries management.