Fungi have occasionally been found in primary root canal infections

Fungi have occasionally been found in primary root canal
infections,49,50 but they are more common in filled root ca?nals in teeth that have become infected some time after
treatment or in those that have not responded to
treatment.51 Overall, the occurrence of fungi in infected
root canals varies between 1% and 17%.52 A large number
of other yeasts have also been isolated from the oral cavity,
including Candida glabrata, C. guilliermondii, C. para?psilosis, C. krusei, C. inconspicua, C. dubliniensis, C. tropi?calis, and Saccharomyces species.51
It has been demonstrated that C. albicans cells are highly
resistant to Ca(OH)2 and that all Candida species (C. albi?cans, C. glabrata, C. guilliermondii, C. krusei, and C. tropi?calis) are either equally high or had higher resistance to
aqueous calcium hydroxide than did E. faecalis.
53,54 Because
C. albicans survives at a wide range of pH values, the alkalin?ity of saturated Ca(OH)2 solution may not have any effect
on C. albicans. In addition, Ca(OH)2 pastes may provide the
Ca2+ ions necessary for the growth and morphogenesis of
Candida. These mechanisms may explain why Ca(OH)2 has
been found to be ineffective against C. albicans.
51
Siqueira et al.55 investigated the antifungal ability of
several medicaments against C. albicans, C. glabrata, C.
guilliermondii, C. parapsilosis, and Saccharomyces cerevi?siae. They reported that whereas the paste of Ca(OH)2 in
camphorated paramonochlorophenol (CPMC)/glycerin had
the most pronounced antifungal effects, Ca(OH)2 in glycer?in or chlorhexidine and chlorhexidine in detergent also had
antifungal activity, but at a lower level than the paste of
Ca(OH)2 in CPMC/glycerin.55 In another study, Ferguson
et al.56 evaluated the in vitro susceptibility of C. albicans
to various irrigants and medicaments. The minimum in?hibitory concentrations of NaOCl, hydrogen peroxide, chlo?rhexidine digluconate, and aqueous Ca(OH)2 were deter?mined. The results showed that NaOCl, hydrogen per?oxide, and chlorhexidine digluconate were effective against
C. albicans, even when diluted significantly.56 Furthermore,
aqueous Ca(OH)2 had no antifungal activity when main?tained in direct contact with C. albicans cells, whereas
Ca(OH)2 paste and CPMC were effective antifungal
agents.56