Photodynamic Therapy as an Adjunctive Treatment for Extrinsic Stains Caused by Chromogenic Bacteria: Case Series

Background/Objectives: Black extrinsic stains (BS) on tooth surfaces are caused by chromogenic bacteria and iron accumulation in oral tissues. These stains often gener-ate aesthetic complaints and psychological impact, particularly in pediatric patients, as they are more prevalent during childhood and less common in adults. Notably, BS are inversely associated with caries prevalence. Standard treatments such as prophy-laxis may lead to early recurrence, enamel wear, and hypersensitivity. Antimicrobial photodynamic therapy (aPDT) may offer a non-invasive adjunctive treatment alterna-tive. This study aims to present a case series involving two pediatric and one geriatric patient treated with aPDT for BS removal. Methods: Two pediatric patients—a 2.5-year-old female and an 8-year-old male—were referred due to widespread BS un-responsive to conventional prophylaxis, despite good oral hygiene and diet. Initial prophylaxis with pumice and Robinson brush removed only ~20% of the stains. aPDT was applied in conjunction with a second prophylaxis, achieving complete stain re-moval. Follow-ups at 1 and 4 months confirmed no recurrence. The geriatric patient presented with additional complications, including hyposalivation and dentin hyper-sensitivity. A split-mouth design was used: methylene blue 0.01% was applied to one side, with the other side serving as control. Red light (660 nm, 6 J/point, 60 seconds, 3 sessions) was administered. The patient reported satisfactory results after the first ses-sion. Results: Pediatric patients showed no recurrence of BS after aPDT. The geriatric patient experienced stain reduction and improved dentin sensitivity. Stain recurrence was noted in one-third of teeth at the 6-month follow-up and treated again at 1 year. Conclusions: aPDT proved effective in BS removal and contributed to managing den-tin hypersensitivity, demonstrating its potential as an adjunctive, minimally invasive treatment across age groups.