Evaluation of Damping Properties of Restorative Materials And Restored Teeth

Objectives: Damping effect of an object is associated with the degree of damage when the object was subjected to an impact force. An object with higher damping property will decrease the maximum internal stress when the impact occurs, thus results in a lower risk of deformation or destruction. Since dental trauma is common ailment clinically, the damping properties of restored teeth were not investigated systemly. In this study, the damping ratios of teeth with and without restoration were detected and compared. The effects of restorative materials on damping properties are evaluated. Methods: Extracted health human maxillary premolars were collected due to orthodontic treatment. The cavity preparation was performed as Black's Class I cavity (with geometry of 4x4x4 mm). Three restorative materials, including amalgam, glass ionomer, and composite resin, were used in this study. Teeth restored with light-cured restorative materials, such as glass ionomer and composite resin, were tested before and after polymerization. Modal testing was carried out to measure the damping ratios of the teeth before and after restorations. One-way ANOVA and Student's t test were used for statistic analysis. Results: The damping ratio of teeth restored with amalgam demonstrated statistically lower value in damping ratio (0.082±0.0018) than those of teeth restored with glass ionomer (0.111±0.011) and composite resin (0.118±0.015, p<0.05). In addition, the damping ratio decreased after polymerization of light-cured restorative materials. Conclusion: Restorative materials have effects on the damping properties of the treated tooth. Choosing restorative materials with adequate damping properties may decrease the prevalence of tooth fracture after restoration.