Objective: The objective of this study was to determine the in vitro susceptibility of Enterococcus faecalis and the most prevalent Candida species as therapy-resistant microorganisms to gutta-percha points containing root canal medications.
Study design: Gutta-percha points containing calcium hydroxide (Calcium Hydroxide Plus Points), chlorhexidine diacetate (Activ Points), or calcium hydroxide-chlorhexidine combinations (CHX/Ca Combi Points) were tested for their ability to inhibit growth of pure cultures of Candida albicans, Candida glabrata, Candida parapsilosis, Candida krusei, Candida tropicalis, Saccharomyces cerevisiae, and Enterococcus faecalis. Approximately 2 x 10(7) microorganisms per assay were suspended in diluted human serum and co-incubated with the gutta-percha points placed in Eppendorf tubes in an incubator for up to 2 weeks. A tube was removed at 1, 2, 3, 4, 7, and 14 days, and then opened and microorganism suspensions were serially diluted in a sterile 0.9% NaCl solution. Aliquots of the dilution steps were streaked onto solid medium. After incubating the plates in an incubator at 37 +/- 1 degrees C for 48 hours, CFU numbers per milliliter of suspension were calculated.
Results: Calcium Hydroxide Plus Points or Activ Points did not exhibit sufficient antimicrobial or anticandidal activity for Enterococcus faecalis, Candida albicans, C. glabrata, C. parapsilosis, C. krusei, or C. tropicalis within 14 days. Only Saccharomyces cerevisiae was susceptible to the calcium hydroxide or chlorhexidine diacetate containing gutta percha points. CHX/Ca Combi Points killed C. albicans, C. glabrata, C. krusei, C. tropicalis, and S. cerevisiae completely. However, E. faecalis and C. parapsilosis were resistant to CHX/Ca Combi points within 14 days.
Conclusion: The results show the gutta percha points containing a mixture of calcium hydroxide and chlorhexidine diacetate have efficacies superior to calcium hydroxide or chlorhexidine diacetate alone against some microorganisms except E. faecalis and C. parapsilosis.