Efficacy of a Handpiece Designed to Prevent Fluid Retraction

Objectives: To determine whether a specially designed antisuction device can prevent the HBV contamination of the dental unit that is caused by suction when the turbine is stopped. Methods: The HBV DNA concentrations in saliva were tested by fluorescent quantitative PCR (FQ-PCR), then the forty patients were choosed and divided into two groups according to the intraoral clinical situations--the concentrations of HBV DNA in their saliva. A sterilized handpieces with or without the new -designed antisuction device was used in each group. HBV DNA was detected by RT-PCR in samples coming back from the handpieces after treatment of the patients. Results: The occurrence-rates of retractions of the two types of handpieces were both low when the patients' salivary concentrations of HBV DNA were low, and there were no significant differences between them(p>0.05). But in the group with higher salivary concentrations, the occurrence -rates of retraction of the new -designed handpiece were lower than those the handpiece without the antisuction device(p<0.05). Conclusions: The occurrence -rates of retraction of the new -designed handpiece was lower in most intraoral clinical situations. Antisuction devices can reduce penetration into the air chamber of a high-speed handpiece.