Effects of Ultrasonic and Air-driven Devices on Pulp Reaction

Background:Numerous ultrasonic applications were proposed such as tooth preparation, maxillofacial surgery, periodontal therapy, and endodontic microsurgery. However, the effects of operation procedure on cutting hard/soft tissue still remain unclear.Objectives:The aim of this study is to test influences of the ultrasonic device on dental pulp tissues in comparison with air-driven high-speed handpieces with an animal model.Methods:The dogs were divided into three groups according to the observation periods (immediate, 1-week and two-week). Class V cavities were prepared on labial surfaces of upper incisors. And then the pulp chamber was perforated with either ultrasonic device or air-driven high-speed dental handpieces (subgroups: Ultrasonic and High-speed). After the observation period, the teeth were extracted and histologically examined under the light microscope.Results: Histological observations revealed less pulpal wound hemorrhage and less pulp tissue laceration in the ultrasonic group. Disturbances of odontoblasts in the pulp tissue were noted in all groups. Both ultrasonic and high-speed groups revealed more inflammatory reaction in 1-week and subsiding inflammation in 2-week.Conclusion:The ultrasonic devices could cause less damage to the dental pulp tissue compared to air-driven high-speed dental handpieces. We expected that the ultrasonic device can be applied to vital pulp therapy, namely direct pulp capping, pulptotomy, or pulpectomy. Further studies about the qualitative and quantitative analysis of pulp inflammation are being conducted.