Damping Effects Of Dental Restorative Materials Using Modal Testing Method

Introduction: Damping effect of a structure correlates with the degree of damage when the structure was sustained to a sudden impact. A structure with higher damping ratio will result in lower damage when impact is occurrence. Since dental trauma is a frequently injury in clinical, the damping properties of human teeth was not investigated systemly. Objectives: The damping ratios of teeth with and without restoration were detected and compared. The effects of restoration materials on damping properties are evaluated in this study. Materials and Methods: Human maxillary premolars were chosen and prepared as Black's Class I cavity (with geometry of 4x4x4 mm). They were divided into three catalogues which restored with amalgam, glass ionomer, and composite resin, respectively. Modal testing was used to measure the damping ratios of the teeth before and after restorations. Student t-test was used for statistic tests. Results: The damping ratio of the teeth before restorations is 0.127±0.0187. The damping ratio of teeth restored with amalgam demonstrated statistically lower value (0.016±0.0025) than those of teeth restored with glass ionomer (0.082±0.009) and composite resin (0.10±0.018, p<0.05). In addition, the damping ratio decreased after polymerization of restorative materials. Conclusion: Different restorative materials had different damping properties. To avoid teeth fractured due to excessive sudden impact force, damping effects should be considered when choosing restorative materials.