To determine whether professionally applied 38% silver diamine fluoride (SDF) reduces the development of new radiation-induced caries (RIC) over 6 months compared with placebo in patients undergoing head and neck radiotherapy.
Approach:
Study Design: Single-center, randomized, single-blind, placebo-controlled pilot clinical trial.
Setting: Conducted at the College of Dentistry, Texas A&M University, in collaboration with Texas Oncology-Baylor Charles A. Sammons Cancer-Center Radiation Oncology in Dallas, Texas.
Participants: Fifty-six patients with oral or pharyngeal cancer scheduled for radiotherapy were enrolled; 36 completed at least 1 follow-up visit and were included in the analysis.
Intervention: Participants received 38% SDF or an identical-appearing placebo consisting of blue-tinted deionized water. The assigned solution was applied to all tooth surfaces before radiotherapy and at 1 and 3 months after radiotherapy.
Randomization: Participants were assigned to SDF or placebo using a computer-generated list with 1:1 allocation and randomly permuted block sizes of 2 and 4.
Key Findings:
Median caries increment was significantly lower with SDF than placebo at 1 month (0.0 vs 1.0), 3 months (1.0 vs 2.0), and 6 months (2.0 vs 3.0).
At 1 month, 72.2% of SDF recipients developed no new caries compared with 23.5% of placebo recipients. At 3 months, the corresponding proportions were 47.1% and 5.9%.
Stimulated salivary flow declined significantly in both groups, but no between-group differences were observed.
Gingival inflammation and oral health–related quality of life did not differ significantly between groups.
No adverse or unanticipated treatment-related effects were reported. SDF-associated discoloration occurred but was not reported as a concern.
Interpretation:
Professionally applied 38% SDF reduced RIC progression despite substantial declines in salivary flow, suggesting that its protective effect operated independently of salivary function. Its rapid professional application and lack of reliance on daily patient adherence may make it a practical addition to oral care before and after head and neck radiotherapy.
Limitations:
The pilot study had a small sample, was conducted at a single center, and included only 6 months of follow-up.
SDF-associated staining may have introduced detection bias because the same clinician administered treatment and assessed outcomes, preventing full examiner blinding.
Plaque index data were not collected.
The findings may not be generalizable beyond the study sample.
Conclusion:
Within the limitations of this randomized pilot trial, professionally applied 38% SDF significantly reduced RIC progression over 6 months compared with placebo. The findings should be interpreted cautiously and require confirmation in larger multicenter studies with longer follow-up.
Combining IL-17 with TNF-alpha showed strong discrimination between carious lesions and healthy controls, but performance was more modest against gingival inflammation.
Increases in apnea-hypopnea events were greatest among patients with an elevated baseline index, while evidence supporting mouth taping remained preliminary.
