Effects of Natural Mouthwash on the Force Degradation of Orthodontic Elastomeric Chains: An In Vitro Experimental Study

Aim: This study aimed to evaluate in vitro the effect of a natural mouthrinse and alcohol-free 0.12% chlorhexidine on force degradation of orthodontic elastomeric chains from four commercial brands: Ormco Generation II Power Chain, TP E-Chain, American Orthodontics, and Morelli. Materials and methods: An experimental design was employed using 108 samples, divided into three groups: Control, chlorhexidine, and natural rinse. Force measurements were taken at baseline, after 24 hours, and after 30 days using a high-precision digital dynamometer. Data were analyzed using a three-way ANOVA (Brand × Rinse × Time) and a multiple linear regression model, with significance set at p < 0.05. Results: The findings revealed a biphasic degradation pattern, characterized by a sharp decline in force during the first 24 hours, followed by a more gradual reduction over the next 30 days. Among the brands, TP demonstrated the lowest force degradation compared to Ormco (approximately -9.79 percentage points), while American Orthodontics and Morelli showed significantly higher losses (approximately +17.31 and +16.17 percentage points, respectively). Exposure to chlorhexidine increased degradation (approximately +4.66 percentage points), whereas the natural mouth rinse did not have a significant overall effect. Additionally, time was a crucial factor: After 30 days, degradation increased by approximately +2.41 percentage points compared to the 24-hour mark. Conclusion: Degradation of elastomeric chains is influenced by the brand, type of mouth rinse, and duration of exposure. The natural mouthrinse was a safe option to prevent accelerated degradation, thus helping to maintain effective therapeutic forces in orthodontic treatments. These findings emphasize the importance of selecting the appropriate chain brand and mouthrinse, as well as considering the frequency of replacement, to optimize outcomes in orthodontic treatment. Clinical significance: The strength loss of elastomeric chains depends on the brand, the type of mouthwash used, and the duration of exposure; orthodontists should consider these factors when planning treatments.