A Scoping Review on Arginine in Caries Prevention

Objectives: Emerging science on arginine or arginine formulations has driven the need to examine the research in the field. The scoping study objectives were (1) to identify the extent, range, and type of evidence on the role of arginine or arginine formulations in caries prevention and (2) to explore the future scope of research on arginine-containing caries-preventive agents.

Methods: A systematic search was performed in PubMed, Scopus, and Web of Science. In vitro studies, clinical trials, narrative reviews, systematic reviews and or meta-analysis, and umbrella reviews or meta-evaluation examining arginine or arginine formulations for caries prevention were included. The data-charting process involved extracting variables followed by evidence synthesis. Arginine variants investigated up to date were discussed to explore future scope of research.

Results: Thirty-nine articles were included for review from 105 identified citations comprising of in vitro studies, clinical trials, and reviews. Most articles studied 1.5% arginine-fluoride toothpaste. Most studies were from Asia, followed by North America, with fewest studies from Europe and South America. Arginine or arginine formulations demonstrated a superior caries-preventive effect compared with their matched controls (including fluorides); however, the evidence is with high risk of bias. Until now, three arginine variants have been investigated with l-arginine monohydrochloride as the least explored variant.

Conclusions: The evidence on the caries-preventive effect of arginine or arginine formulations has a high risk of bias. High-quality clinical trials are needed to assess the caries-preventive potential of arginine in commercial formulations. The role of l-arginine monohydrochloride in caries prevention can further be explored by incorporating in self-applied and professionally applied caries-preventive agents.