Immediate Effects of Biomimetic Hydroxyapatite Toothpaste and Mouthwash on Dentin Hypersensitivity: A Randomized Controlled Trial

Background/Objectives: Dentin hypersensitivity (DH) is associated with gingival recession and dentin exposure. Biomimetic hydroxyapatite (HAp) reduces DH by occluding dentinal tubules, with conventional toothpaste formulations showing benefits. High-density HAp mouthwashes may enhance bioavailability, but comparative evidence is scarce. This trial assessed the immediate desensitizing efficacy of a conventional HAp toothpaste and a high-density HAp mouthwash after professional oral hygiene. Methods: One hundred participants were randomized 1:1 to Biorepair® (Coswell S.p.A., Funo, BO, Italy) Total Protection Toothpaste (Control) or Biorepair® (Coswell S.p.A., Funo, BO, Italy) High-Density Mouthwash (Test). Assessments were performed at baseline (T0), post-debridement (T1), and after product use (T2). The primary endpoint was patient-level Schiff Air Index (SAI). Secondary endpoints included tooth-level SAI, Visual Analog Scale (VAS) scores, and gingival recession (GR). The trial was registered at ClinicalTrials.gov (NCT07057141) and followed CONSORT 2025 guidelines. Friedman and Dunn’s tests and regression models were applied. Results: Both groups showed significant reductions in hypersensitivity. Patient-level mean SAI decreased from 1.47 to 0.66 in the Control and from 1.48 to 0.45 in the Test group, while VAS declined from 3.66 to 1.57 (Control) and from 4.15 to 1.37 (Test). Post hocPost-hoc analyses showed significant intragroup reductions between T0/T1 and T2 in both groups, with no significant differences between groups at any timepoint. GR remained stable across the study. Regression analyses identified follow-up time and GR as significant predictors, whereas treatment allocation was not, indicating that the acute advantage of the mouthwash at T2 did not persist once longitudinal trends were considered. Conclusions: Both HAp formulations effectively reduced dentin hypersensitivity 30 s after application. The high-density mouthwash exhibited slightly lower mean values at T2, although these differences were not statistically significant.