Radiation-related caries in oral cancer: Molecular pathogenesis, cellular mechanisms, and contemporary management...

Radiation-related caries (RRC) is a rapidly progressive and distinctive complication of radiotherapy in patients with oral cancer. Unlike conventional dental caries, it demonstrates atypical clinical patterns, accelerated destruction, and multifactorial pathogenesis involving salivary dysfunction, direct hard tissue injury, and ecological microbial shifts.

To critically review the molecular mechanisms, cellular pathways, clinical manifestations, diagnostic advances, and contemporary prevention and management strategies related to RRC.

A narrative review of published literature was conducted focusing on salivary gland dysfunction, radiogenic injury to enamel and dentin, matrix metalloproteinase activation, pulpal and microvascular changes, mitochondrial dysfunction, stem cell senescence, oral microbiome dysbiosis, diagnostic tools, and emerging preventive and therapeutic approaches.

Radiation reduces salivary flow, buffering capacity, and mineral content, predisposing teeth to demineralization. Simultaneously, reactive oxygen species induce enamel and dentin damage, collagen degradation, dentino-enamel junction instability, and increased fracture susceptibility. Radiation also promotes matrix metalloproteinase activation, chronic pulpal hypoxia, mitochondrial oxidative injury, and senescence of salivary gland progenitor cells, impairing tissue regeneration. Microbiome alterations favor cariogenic species such as Streptococcus mutans with enhanced virulence and biofilm formation. Clinically, RRC commonly affects cervical margins, cusp tips, and incisal edges, progressing rapidly toward crown destruction. Preventive strategies include salivary-sparing radiotherapy, gland transfer procedures, sialogogues, topical fluoride, CPP-ACP formulations, silver diamine fluoride, and structured surveillance. Novel approaches such as AI-assisted diagnosis, antimicrobial peptides, matrix metalloproteinase inhibitors, hydrogels, and nanocarrier-based delivery systems show translational promise.

RRC is a complex radiation-induced oral disease driven by convergent structural, biological, and microbial mechanisms rather than xerostomia alone. Optimal management requires early risk assessment, integrated prevention, timely restorative care, and mechanism-targeted therapies to preserve oral health and quality of life in oral cancer survivors.