Mouthguard retention: Is design oraccuracy of fit more critical?

Aim: To examine the influence of the accuracy of fit on mouthguard retention in relation to mouthguard outline location. Materials and Methods: Mouthguards were fabricated on a fully dentate maxillary cast with 4-mm-thick ethylene vinyl acetate sheets using a welldried cast (VD) and on a wet cast (VW) with a vacuum-forming machine. Mouthguards were also made with a pressure-forming machine (P). The mouthguard outline was set at 4 mm from the cervical margin (control, C), the palatal outline was set at the cervical margin (Pa), and the buccal outline was extended to the buccal fold (Bu). A dislodging force perpendicular to the occlusal plane was applied at the first molar on the universal testing machine. Results were analyzed using ANOVA with Scheffe's test (P < .05). Results: Using the VW, the retentive forces were statistically smaller at Pa compared to C or Bu (C: 58 ± 17 gf, Pa: 36 ± 7 gf, Bu: 50 ± 8 gf) (P < .05). There were no statistical differences between VD (C: 116 ± 27 gf, Pa: 86 ± 15 gf, Bu: 92 ± 7 gf and group P (C: 133 ± 31 gf, Pa: 139 ± 24 gf, Bu: 136 ± 17 gf). Conclusions: The results indicate that mouthguard retention is closely related to the accuracy of fit at the cervical undercut area rather than the outline location. [ABSTRACT FROM AUTHOR]