Development of new artificial models for splint rigidity evaluation

Abstract – Aim: We developed two versions of an artificial model and assessed their suitability for splint rigidity evaluation. These models allowed the simulation of traumatically loosened teeth and the use of the acid‐etch technique for splint application. Materials and methods: A straight and half‐round arch bar model with bovine tooth facets were manufactured. Using the Periotest method, tooth mobility was evaluated before (PTVpre) and after (PTVpost) splinting. Two types of previously investigated wire‐composite splints, WCS1 (Dentaflex 0.45 mm; Dentaurum) and WCS2 (Strengthens 0.8 × 1.8 mm; Dentaurum), were applied (n = 10) to each model. The relative splint effect (SpErel = ΔPTV/PTVpre) was calculated, and the working times for the models and splints were evaluated. Student’s t‐test and the Mann–Whitney U‐test were employed with Bonferroni correction for multiple hypotheses. Results: When comparing the relative splint effect of the ‘injured’ central incisors between the models within one splint type, differences were only found for tooth 21 (WCS2; P < 0.008); for comparisons of splints within one model type, differences were detected for both incisors and model types (P < 0.008). With the straight model, significantly less working time was necessary (P < 0.05). Conclusion: Using these models for in vitro splint rigidity evaluation, the splints can be applied with the acid‐etch technique and tooth mobility can be individually adjusted. WCS1 is considered flexible compared to the more rigid WCS2. The results from the straight and the round model were predominantly closely related to each other. In terms of working time, the straight model is superior to the round model.