IJOMAHIP Published Article Details

Abstract Background. Maintaining consistent orthodontic force is essential for efficient tooth movement; however, non-latex orthodontic elastics are susceptible to progressive force degradation under intraoral conditions. Salivary pH may affect the mechanical stability of polyurethane elastics, yet its influence across different immersion periods remains poorly understood. This study aimed to evaluate the force degradation of non-latex orthodontic elastics exposed to different salivary pH levels and immersion periods and to develop proposed clinical guidelines based on the findings. Methods. An in vitro experimental study was conducted using fifty-four non-latex orthodontic elastics divided into nine experimental groups (n= 6 per group) according to three salivary pH conditions (5.0, 7.0, and 8.5) and three immersion periods (24 hours, 48 hours, and 1 week). The elastics were immersed in artificial saliva maintained at 37°C, and force degradation was measured using a calibrated digital force gauge. Data were analyzed using two-way analysis of variance (ANOVA) followed by Bonferroni post hoc test, with the level of significance set at p < .05. Results. Force degradation increased significantly with longer immersion periods (p < 0.001), with the greatest force loss observed after one week. Salivary pH also significantly affected force degradation (p <.001), wherein acidic conditions produced the highest force loss, followed by alkaline conditions, while neutral pH demonstrated the lowest degradation. Mean force degradation was highest under acidic conditions at one week (57.95 ± 3.10 N), followed by alkaline conditions (50.42 ± 3.32 N) and neutral conditions (43.30 ± 3.19 N). No significant interaction was observed between salivary pH and immersion period (p = .167), indicating that both variables independently influenced force degradation. Conclusion. Salivary pH and immersion time significantly influenced the force degradation of non-latex orthodontic elastics under the conditions tested. Acidic conditions produced the greatest degradation, while neutral conditions produced the lowest, and degradation increased with prolonged immersion. The proposed guidelines emphasize consideration of salivary pH and duration of elastic use when monitoring non-latex orthodontic elastics. However, these preliminary guidelines require validation through dynamic and in vivo studies before specific clinical replacement protocols can be established. Keywords: Artificial saliva; force degradation; non-latex orthodontic elastics; orthodontic materials; polyurethane elastics; salivary pH