การศึกษาความชุกของเชื้อเอนเทอโรคอคคัส ฟีคาลิสในฟันที่ล้มเหลวจากการรักษาคลองรากฟันที่มีรอยโรคปลายรากด้วยวิธี Real-time PCR และ การเพาะเลี้ยงเชื้อ

Abstract

Enterococcus faecalis is commonly found in failed root canal treated teeth with periradicular lesions, and there is limited information about the prevalence of E. faecalis in failed root canal treated teeth with periradicular lesions in Thailand. Therefore, the objective of this study was to examine the prevalence of E. faecalis in failed root canal treated teeth with periradicular lesions by real-time PCR and cultivation. Thirty-six samples were collected from 36 root canals with periradicular lesions. All samples were cultured on blood agar and selective medium for detection of enterococci. E. faecalis was identified by colonial morphology, biochemical properties and molecular method, and a number of total bacteria and E. faecalis were recorded. Results showed that the prevalence of E. faecalis in the failed root canal treated teeth with periradicular lesions was 33.3% (11/33 samples) by cultivation and 88.9% (32/36 samples) by real-time PCR. Moreover, the hemolytic E. faecalis strains were found in 13 of 49 strains (26.5%). The hemolytic E. faecalis strains were found to be related to the teeth with sinus tract opening and sensitive/pain to percussion (100%) while only 12.5% of the non-hemolytic strains were found in such conditions. In conclusion, intraradicular infection was still the main cause of the failed root canal treated teeth with periradicular lesions and the prevalence of E. faecalis was 33.3% and 88.9% by culture and real-time PCR, respectively. The hemolytic E. faecalis strains were related to more severe clinical symptoms. This may be due to the hemolytic strains having more virulence factors than non-hemolytic strains, further investigations are needed.