Clinical evidence on 5% potassium nitrate toothpaste and diode-laser therapy with or without sodium fluoride for dentin hypersensitivity: a scoping review

Abstract Background Dentin hypersensitivity (DH) arising from exposed dentin is managed using home-use desensitizing toothpastes and professionally delivered laser therapy. This scoping review mapped clinical evidence on toothpastes containing exactly 5% potassium nitrate (KNO₃), diode-laser therapy, and diode laser combined with sodium fluoride (NaF). Methods Following Joanna Briggs Institute methodology and PRISMA-ScR, PubMed/MEDLINE, Embase, Scopus, CENTRAL, and Google Scholar were searched for studies published from 1 January 2015 to 14 June 2026. Eligible human clinical studies evaluated home-use 5% KNO₃ toothpaste, diode-laser therapy, or diode laser combined with NaF for DH arising from exposed dentin. Two reviewers independently screened records and full texts. Data were charted by one reviewer and independently verified by another. Findings were synthesized narratively by intervention category and follow-up period. Results The searches identified 315 records, and 23 unique studies met the eligibility criteria. Three directly compared home-use 5% KNO₃ toothpaste with diode laser; six evaluated other eligible KNO₃ toothpastes, nine diode laser alone, and five diode laser combined with NaF. Direct comparisons generally favored laser-containing arms for earlier short-term relief, but small samples, heterogeneous protocols, and follow-up of no more than 12 weeks prevented conclusions of universal superiority. KNO₃ toothpastes generally produced progressive improvement over four to eight weeks, although findings applied to complete multi-active formulations. Diode-laser superiority over active comparators or sham was inconsistent, and adding NaF did not consistently improve outcomes. Major gaps included incomplete laser dosimetry, unaddressed clustering of multiple teeth, limited patient-reported outcomes, and inconsistent adherence and safety reporting. Conclusions Several approaches may reduce DH, but no toothpaste, diode-laser protocol, or diode-laser-plus-NaF regimen was universally superior. Standardized protocols, cluster-adjusted analyses, validated patient-reported outcomes, safety monitoring, and longer direct comparative follow-up are needed. Trial registration Open Science Framework, doi: https://doi.org/10.17605/OSF.IO/MV9TG ; retrospectively registered on 23 August 2025.