Effect of sterilization between the class B autoclave and the cassette autoclave inside the chamber of high-speed dental handpiece

Objective To compare the sterile effects inside the chambers of high-speed dental handpieces between using the class B autoclave and the cassette autoclave.Methods The infected high-speed handpieces were divided int two groups called A and B group respectively with random and each group accumulated 40 handpieces.Then 40 handpieces in group A were washed by the dental instrument washer/disinfector and divided into two group of A1 and A2 with random and each group accumulated 20 handpieces.The handpieces in group A1 were sterilized by the class B autoclave and group A2 by the cassette autoclave.The other 40 handpieces in group B were not washed by the dental instrument washer/disinfector and divided into two group of B1 and B2 with random and each group accumulated 20 handpieces too.The handpieces in group B1 were sterilized by the class B autoclave and group B2 by the cassette autoclave.All above the 80 handpieces were taken a simple in the chamber to make bacterial cultures before and after sterilization.Results None of the 40 handpieces cleaned with the dental instrument washer/disinfector showed bacterial examination positive in the chamber no matter what autoclave sterilized with.The handpieces without washing with the dental instrument washer/disinfector prior sterilization can completely sterilized by the class B autoclave,but two handpieces sterilized by the cassette autoclave showed bacterial examination positive in the chamber.Conclusion The bacteria in the chambers of high-speed handpieces which washed by dental instrument washer/disinfector prior sterilization could be sterilized completely by two autoclaves.The procedure of special washing was very important in dental handpieces sterilization.