Mouthguard retention: is design or accuracy of fit more critical?
OBJECTIVE
To examine the influence of the accuracy of fit on mouthguard retention in relation to mouthguard outline location.


METHODS
Mouthguards were fabricated on a fully dentate maxillary cast with 4-mm thick ethylene vinyl acetate sheets using a well-dried 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 Ca 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.
Maeda
Yoshinobu
Y
Department of Prosthodontics and Oral Rehabilitation, Osaka University Graduate School of Dentistry, Osaka, Japan. ymaeda@dent.osaka-u.ac.jp
Yonehata
Yuri
Y
Satoh
Hajime
H
D003781:Denture Retention; D004867:Equipment Design; D006801:Humans; D003765:Models, Dental; D009064:Mouth Protectors; D011145:Polyvinyls; D011312:Pressure; D014618:Vacuum
D011145:Polyvinyls; C016438:ethylenevinylacetate copolymer