The Role of the Interproximal Enamel Reduction in Orthodontics: A Systematic Review

Background: The aim of this systematic review was to critically evaluate the clinical indica- tions, the techniques, and the effects of interproximal enamel reduction (IPR). Methods: A systematic review of the existing literature was carried out following the PRISMA guide- lines in the following databases: PubMed-Medline, Scopus, Embase, Web of Science, and Cochrane. The search was conducted according to the established inclusion and exclusion criteria until March 2025. Results: A total of 420 articles were identified. Only 23 were selected for the analysis. The efficiency and validity of IPR as a non-extraction protocol adopted in several orthodontic cases was reported in all selected studies. No negative effects in terms of enamel demineralization, residual irregularities, caries incidence, and periodontal damages were reported. Using oscillating mechanical techniques was more efficient than using manual ones in terms of efficiency, predictability, and respect of enamel surfaces. Overall, the quality of the selected articles was low. More randomized controlled clinical trials with in vivo tests, research with longer follow-up times, and high-quality studies are needed to assess more valid statements. Conclusions: Higher accuracy of enamel reduction is achieved by means of oscillating mechanical techniques, which allows for more effective and predictable IPR procedures, as well as more preserved residual enamel surfaces.