Longitudinal changes in mouthguard fit: Reliability of an evaluation method.

BACKGROUND/AIM: A mouthguard should be replaced when it deteriorates or becomes deformed as a result of the softness or flexibility of the material. The question, however, is how long can one use a mouthguard and when should one replace it with a newly made mouthguard? The aim of this study was to develop an improved method for measuring the fit of mouthguards based on previous reports and to examine its reliability. MATERIAL AND METHODS: Silicone fit-testing material was applied to the inner surface of the mouthguards of 12 participants, and the mouthguards were inserted into the participants' oral cavity. After the test material had set, the mouthguard was weighed. The intra-rater reliability and inter-rater reliability were analyzed using intraclass correlation coefficients. RESULTS: The intra-rater reliability was 0.813 (P < .001), and the inter-rater reliability was 0.817 (P < .001). Both values were greater than 0.7, suggesting that this measuring method had sufficient reliability. CONCLUSIONS: The results of this study indicate that mouthguard fit can be evaluated longitudinally to determine the optimal time to replace a mouthguard.