Evaluation of the aerobic microorganisms presence in calcium phosphate cement blocks submitted to three methods of sterilization

Abstract

Calcium phosphate previously molded can be used for reconstruction in oral maxillofacial regions. The previous sterilization of this biomaterial is an important step on the prevention of inflammatory and infectious processes. Four blocks of calcium phosphate cement (Ca3(PO4)2) were used in this work, divided into fur groups, each one consisting of one part. The sterilization methods used to the three experimental groups were the following: autoclave or steam sterilization (Groups 1a and 1b), peroxide hydrogen (Groups 2a and 2b) and ethylene oxide (Groups 3a e 3b). The control group (Ca and Cb) was not submitted to sterilization. Initially the each block was placed in tubes containing tryptic soy broth TSB (Groups a). The resulting liquid media were placed in Petri plates containing blood agar (Groups b). The culture media suffered incubation process in aerobiosis and the results were determined through bleary or not bleary liquid media or through the presence or not of bacterial colonies in solid media. Contrary to the control group, there was no bacterial growth in any of the experimental groups. The result of the bacterioscopy examination or GRAM method of the control group showed numerous Staphylococcus sp and Streptococcus sp. It can be concluded that the methods tested, that is, the autoclave or steam sterilization, ethylene oxide peroxide hydrogen are efficient for aerobios. The use of the blocks of calcium phosphate Sterilization method for implantation in vivo is recommended and as well as new studies for evaluation of mechanical properties of this material after the sterilization process.