title: A Method for Detecting the Deterioration in the Shock Absorption Capability of Mouthguards.
abstract: Objective methods for mechanical assessment of mouthguards used for a prolonged period of time are currently unavailable. The aim of this experimental study was to establish a quantitative method for assessing the preventive effect of mouthguards. 10 participants volunteered for this study. Impact loads were simulated by dropping a 250-g steel rod from a height of 100 mm onto upper front teeth of 10 custom ethylene vinyl acetate mouthguards fixed to a steel receiving rod. The mean output from load cells equilaterally placed between plates at the base of the apparatus was measured as the impact pressure (N). Its attenuation ratio (%) was calculated as the ratio of the difference in impact pressures without and with a mouthguard to impact pressure without a mouthguard. Impact pressure with mouthguard was approximately 60% of that without mouthguard in all cases. Intraclass correlations showed excellent intra-rater and inter-rater reliability for attenuation ratio (0.98 and 0.94, respectively). Bland-Altman plots indicated lack of systematic bias. The results suggest that attenuation ratio of impact pressure calculated by the proposed method is a valid criterion for assessing the preventive effect of mouthguards. The method may enable early detection of mouthguard deterioration and their timely replacement.
authors.affiliation: Department of Prosthodontics, Gerodontolgy and Oral Rehabiliation, Osaka University Graduate School of Dentistry, Suita, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Tanaka
authors.affiliation: Department of Prosthodontics, Gerodontolgy and Oral Rehabiliation, Osaka University Graduate School of Dentistry, Suita, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Miyanaga
authors.affiliation: Department of Prosthodontics, Gerodontolgy and Oral Rehabiliation, Osaka University Graduate School of Dentistry, Suita, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Maeda
authors.affiliation: Department of Prosthodontics, Gerodontolgy and Oral Rehabiliation, Osaka University Graduate School of Dentistry, Suita, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Abe
authors.affiliation: Department of Prosthodontics, Gerodontolgy and Oral Rehabiliation, Osaka University Graduate School of Dentistry, Suita, Japan.
authors.forename: S
authors.initials: S
authors.lastname: Miwa
mesh_terms: D004867:Equipment Design; D019544:Equipment Failure Analysis / Q000379:methods*; D006801:Humans; D009064:Mouth Protectors; D011312:Pressure; D015203:Reproducibility of Results; D013177:Sports; D013314:Stress, Mechanical; D016474:Weight-Bearing