In vitro susceptibility of oral Candida albicans strains to different pH levels and calcium hydroxide saturated aqueous solution.
Candida albicans is present in the oral cavity and in the whole digestive tract of humans and other animals, being frequently related to endodontic treatment failure. The present study determined the incidence of C. albicans in the oral cavity and the susceptibility of isolates to different pH values and saturated calcium hydroxide aqueous solution at pH 12.5. Sixty-five patients attending the Endodontic Clinic at the Sagrado Coração University participated in the study. The collected samples were cultivated in selective media for C. albicans and the isolates were tested in terms of resistance to both alkaline pH and saturated aqueous solution of calcium hydroxide. In relation to time variables, yeast viability was assessed by the Sabouraud's agar culture and fluorescein diacetate and ethidium bromide fluorescent staining method. Results from the different pHs and experimental times, including those from different techniques measuring fungal viability, were compared using the chi-square and Fisher's exact tests (α=0.05). The yeasts became completely inviable after 48 h of contact with the calcium hydroxide solution. On the other hand, when exposed to the alkaline culture broth, the yeasts were found to be viable at pHs 9.5 and 10.5 for up to 7 days. In conclusion, C. albicans can only be completely inhibited by direct contact with saturated calcium hydroxide aqueous solution after 48 h of exposure.
Department of Biological Sciences, Center of Health Sciences, Sagrado Coração University, Bauru, SP, Brazil. phweck@terra.com.br
Paulo Henrique
PH
Weckwerth
Cristiane
C
Carnietto
Ana Carolina Villas Boas
AC
Weckwerth
Marco Antonio Hungaro
MA
Duarte
Milton Carlos
MC
Kuga
Rodrigo Ricci
RR
Vivan
D002126:Calcium Hydroxide / Q000494:pharmacology*; D002176:Candida albicans / Q000187:drug effects* / Q000302:isolation & purification; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008826:Microbial Sensitivity Tests; D009055:Mouth / Q000187:drug effects / Q000382:microbiology*; D012388:Root Canal Irrigants / Q000494:pharmacology*; D013194:Staining and Labeling; D015003:Yeasts / Q000187:drug effects*
D012388:Root Canal Irrigants; D002126:Calcium Hydroxide