The Antimicrobial Efficacy of Calcium Hydroxide Preparations on Selected Microorganisms

Objectives:The aim of this study was to evaluate the antimicrobial activity of two calcium hydroxide formulatýons (Multical, Sultan+distilled water) in infected dentinal tubules. Four microorganisms, strains of ATCC Enterecoccus faecalis (ATCC 29212), Candida albicans (ATCC 10231), Staphylococcus aureus (ATCC 6538) and Pseudomonas aeroginosa (ATCC 27853) were used. . Methods:140 freshly extracted single rooted and canaled human premolar and insicor teeth were prepared wýth step down tecnique up to no. 40 file to be 1mm. short of the apex. Outer root surfaces were covered wýth no.0 nail polish and the roots were sectioned into two pieces longitudinally. 280 pieces were obtained and autoclaved at 1 atm. pressure 124⁰C for 15 minutes.Two groups, 120 teeth each, were formed and remaining 40 teeth were used for positive and negative controls. The sections were then infected wýth the selected microorganisms at 37⁰C for 7 days by means of adding fresh suspensions of the microorganisms every 24 hours.The infected dentin surfaces were dressed wýth calcium hydroxide formulations. At the intervals 0, 24, 48, 72 h and 7 days, the calcium hydroxide formulations were removed usýng distilled water and sterilized hand instruments. Then the sections were dried wýth sterilized cotton pellets and incubated at 37⁰C for 24 hours for microbial growth. Results:According to the microbial growth controls at 0, 24, 48, 72 hours and 7 days, both calcium hydroxide formulations were found to be antimicrobial and significantly reduced the number of microorganisms (p<0.05). Multical was 50% more effective only on Staphylococus aureus than Sultan+distilled water. Conclusions: Both calcium hydroxide preparatýons limited the microbial growth but could not completely eliminate the selected microorganisms.