Comparative evaluation of postfabrication thickness of thermoformed 3 mm and 4 mm mouthguards on crowded and proclined malocclusion models: An in vitro study.

PURPOSE: To evaluate and compare the postfabrication thickness (PFT) of thermoformed mouthguards fabricated from 3 mm and 4 mm ethylene-vinyl acetate (EVA) sheets on crowded and proclined dental models. MATERIALS AND METHODS: An in-vitro study was conducted using 20 mouthguards fabricated on dental stone models with crowded and proclined maxillary anterior teeth. Pressure-molded mouthguards were made using 3 mm and 4 mm EVA sheets. PFT was measured at standardized labial, buccal, and sulcus regions using an Iwanson caliper. Statistical analysis was performed using ANOVA, Tukey's post hoc test, and unpaired t -test ( P < 0.05). RESULTS: Significant thickness reduction was observed in both 3 mm and 4 mm mouthguards. In crowded dentition, 42%-61% thinning occurred at labial surfaces and 53%-71% at the sulcus, while proclined dentition showed 40%-60% and 51%-67% thinning, respectively. Maximum thinning occurred at canines, whereas molars showed the least reduction. CONCLUSION: Thermoforming causes substantial reduction in mouthguard thickness, particularly in anterior regions. Dental alignment influences final thickness, and clinicians should consider postfabrication thinning when selecting EVA sheet thickness to ensure adequate protection.