Assessment of periradicular microbiota by DNA‐DNA hybridization

Abstract

In the present study the "checkerboard" DNA-DNA hybridization technique was used to identify bacteria in periapical endodontic lesions of asymptomatic teeth. Thirty-four patients with root-filled teeth and apical periodontitis were divided into two groups, each containing 17 patients. In Group 1, a marginal incision was performed during surgery to expose the lesion, and in Group 2, a submarginal incision was applied. The gingiva and mucosa were swabbed with an 0.2% chlorhexidine gluconate solution prior to surgery. Bacterial DNA was identified in all samples from the two groups using 40 different whole genomic probes. The mean number (+/- SD) of species detected was 33.7 +/- 3.3 in Group 1 and 21.3 +/- 6.3 in Group 2 (P < 0.001). The majority of the probe-detected bacteria were present in more lesions from Group 1 than from Group 2. The differences were most notable for Campylobacter gracilis, Porphyromonas endodontalis, Propionibacterium acnes, Capnocytophaga gingivalis, Fusobacterium nucleatum ssp. nucleatum, Fusobacterium nucleatum ssp. polymorphum, Prevotella intermedia, Treponema denticola, Streptococcus constellatus and Actinomyces naeslundii I. Bacterial species such as Actinobacillus actinomycetemcomitans and Bacteroides forsythus were detected in more than 60% of the lesions from both groups. Also, P. endodontalis was abundant in periapical tissue. The data supported the idea that following a marginal incision, bacteria from the periodontal pocket might reach the underlying tissues by surgeon-released bacteremia. The study provided solid evidence that bacteria invade the periapical tissue of asymptomatic teeth with apical periodontitis. The detection of much more bacteria with the "checkerboard" DNA-DNA hybridization method than has previously been recovered by anaerobic culture indicated that the endodontic (and periodontal) microfloras should be redefined using molecular methods.

Use of Multiple-Displacement Amplification and Checkerboard DNA-DNA Hybridization To Examine the Microbiota of Endodontic Infections

“…Previous studies have employed DNA probes to less than 50 bacterial species (12,20,49,50,56), compared with the 77 examined in the present study. Thus, a range of taxa far wider than previously recognized was detected.…”

“…This technology permits the detection of microbial species that are difficult to grow as well as uncultivated and unrecognized phylotypes (34), which would lead to a better understanding of the oral microbiota, including endodontic infections (19,35,49,56).…”

Characterization of Microbiota of Root Canal-Treated Teeth with Posttreatment Disease

“…Enterococcus faecalis has been the most frequently detected species in root canal-treated teeth as revealed by both culture and molecular studies (5,8,11,12,16,23,24,26,30,31), but recent studies have called into question its etiologic role in posttreatment disease (7,15,20,31). Moreover, taxa related to several other genera, including Streptococcus, Dialister, Fusobacterium, Filifactor, Parvimonas, Prevotella, Propionibacterium, and Pyramidobacter, have also been detected in treated teeth (5,8,11,12,15,20,22,26,27,29,30).The purpose of this molecular study was 2-fold. First, the samples from root canal-treated teeth with posttreatment apical periodontitis undergoing retreatment were surveyed for the presence of 28 bacterial taxa using the reverse capture-checkerboard DNA-DNA hybridization approach.…”

Comparison of 16S rDNA-based PCR and checkerboard DNA–DNA hybridisation for detection of selected endodontic pathogens

“…In recent years, molecular methods have also been used to investigate the microbiota associated with infected root canals and with acute periapical abscesses [2,[9][10][11][12][13][14][15][16][17][18][19][20]. These methods have provided significant additional knowledge regarding the composition of the endodontic microbiota.…”