THE USE OF EXTRACTED TEETH FOR IN-VITRO BONDING STUDIES - A REVIEW OFINFECTION-CONTROL CONSIDERATIONS

Objective. Infection control concerns regarding the handling of teeth for research purposes have prompted investigators to evaluate the effe cts of disinfection/sterilization on extracted teeth. The objectives o f this literature review were to assess the reported findings of the e ffect of disinfection or sterilization on teeth used for in vitro bond ing studies and make recommendations on their use. Methods. A search o f the literature was performed to obtain background information on inf ection control guidelines and current findings regarding disinfection or sterilization of extracted teeth. Published articles addressing the effects of different disinfection and sterilizing procedures on the t ooth, such as structural changes of dentin and dentin permeability or effect on bond strengths, were examined and compared for agreement or disagreement of findings. The review was organized by the type of disi nfection or sterilization method utilized by the investigators. These methods were evaluated in an attempt to address whether disinfection/s terilization of extracted teeth can be recommended or if the procedure simply produces another variable. Results. Formalin, chemical heat st erilization (Chemiclave), autoclave, ethylene oxide and gamma radiatio n methods of disinfection/sterilization have been investigated for the ir effects on extracted teeth. When the effect of formalin storage on dentin bond strengths was examined, investigator results were extremel y varied. Autoclave and chemical sterilization were found to produce c omparable dentin bond results when compared to controls. Gamma radiati on did not produce structural changes in the dentin but it currently h as not been investigated for its effect on dentin bond strength. And w hile ethylene oxide produced similar dentin bond strength results when compared to controls, its use as a sterilant was determined to be ine ffective. Significance. Investigators have found formalin storage to b e effective for infection control purposes. It cannot, however, be rec ommended as a storage medium for dentin bonding studies due to the var iability in dentin bond strengths resulting from its use. Ethylene oxi de is also not recommended due to its inability to effectively sterili ze teeth. Chemical heat and autoclave sterilization methods are recomm ended for preventing cross-contamination during in vitro dentin bondin g research. This recommendation is based on current research findings which examined the effect of these sterilization methods on dentin and dentin bond strengths.