Effectiveness of silver diamine fluoride in preventing radiation-induced caries: A pilot study

Radiation-induced caries (RIC) is a major complication of head and neck cancer radiotherapy. This study evaluated the effectiveness of professionally applied 38% silver diamine fluoride (SDF) in preventing coronal and root RIC.

In this randomized, single-blind, placebo-controlled trial, 56 patients were assigned to receive topical 38% SDF or placebo before radiotherapy and at 1 and 3 months after radiotherapy. The primary outcome was caries increment, measured as the number of new decayed, missing (due to caries), or filled tooth surfaces at 1, 3, and 6 months. Secondary outcomes were stimulated salivary flow rate, buffering capacity, gingival index, and oral health-related quality of life.

Thirty-six participants completed at least 1 follow-up visit (18 SDF, 18 placebo). Mean (SD) participant age was 61 (13) years, and most were men (78.0%). Median caries increment was significantly lower in the SDF group at 3 months (1.0 vs 2.0; P = .027) and 6 months (2.0 vs 3.0; P = .030). At 3 months, 47.1% of SDF participants developed no new lesions compared with 5.9% of those in the placebo group (P = .017). Stimulated salivary flow decreased significantly in both groups, with no between-group differences. No significant differences were observed in gingival inflammation or quality of life measures.

Topical 38% SDF reduced RIC progression despite profound hyposalivation, supporting its use as a practical chairside preventive intervention for patients undergoing head and neck radiotherapy.

Because SDF is fast, professionally applied, and does not rely on patient compliance, it may be a valuable addition to oral care protocols before and after radiotherapy. This clinical trial was registered at ClinicalTrials.gov. The registration number is NCT05403125.