In vitro demineralization techniques used to form white spot as an initial caries lesion: a systematic review

Abstract

Objective: The objective of this systematic review was to describe and compare the most commonly used in vitro demineralization techniques for the formation of white stain as an initial caries lesion..

Methods: The present study is framed in the updated guide for the publication of systematic reviews PRISMA 2020. A systematic search of the scientific literature was carried out to identify original research that met the eligibility criteria, using the PICO model for systemic reviews. The search words were: caries, white spot lesion, in vitro and demineralization. In vitro studies with clear and replicable methodology were included, systematic reviews, in vivo studies and those without sufficient methodological detail were excluded. The search was carried out in LILACS, Pubmed and Web of Science, for articles published during the year 2024.

Results: There were 29 full articles included for the systemic review that met all eligibility criteria. The demineralization technique with acid solutions was used in 65.52% of the studies (20 of the 29 articles), with acetic acid being the most common acid solution with 44.83%. The pH cycling technique was used in 31.03% of the studies (9 of 29 articles), with a predominance of acetic acid in 27.59% of the cases. The use of acidic solutions allows a controlled condition of demineralization, the pH varied between 4.0 and 5.5 of acids, with a higher frequency of pH of 4.5; Exposure time ranged from 36 hours to 22 days, with the range of 4 days being more common. The use of pH cycles simulate dynamic conditions of demineralization and remineralization, similar to the oral medium, solutions with pH of 4.4 were alternated in demineralization and pH of 7.0 for remineralization; The cycles had variable exposure times, 6 hours for demineralization and 18 for remineralization, repeated for 5 to 10 days.

Conclusion: Demineralization with acid solutions is the most widely used technique due to its simplicity and experimental control. Demineralization using pH cycling offers greater similarity to clinical conditions, but requires a more complex protocol. No in vitro technique presents an accepted standard formula for white spot formation as an initial caries lesion, highlighting the need to establish uniform guidelines in future studies.