Using autofluorescence to detect bacterial contamination in root fractures.

OBJECTIVES: Conventional methods for detecting root fractures cannot assess their depth or bacterial contamination. This study was designed to measure the autofluorescence emitted from a root fracture, with the aim of determining whether this is a suitable method for quantifying the depth and bacterial invasion of a fracture. METHODS: This in vitro study investigated 33 mandibular second molars with periapical lesions that had been extracted after finding root fractures in endodontically treated teeth during intentional replantation or diagnostic surgery. The root fractures were scanned using a fluorescence technique, and the association between fluorescence parameters and fracture depth was analyzed. The significance of the association between the red fluorescence among autofluorescence parameters and bacterial contamination within the fracture was examined. RESULTS: When the depth of the root fractures was evaluated by micro computed tomography, the scattering of light in the fractures increased with depth, and there was a gradual increase in the quantitative fluorescence parameter indicating the deepest point (ΔFmax) in the fractures. In addition, we observed red fluorescence on the outer surface of deeper fractures. The tooth fractures exhibiting red fluorescence were evaluated for bacterial contamination associated with red-fluorescent porphyrin, which revealed bacterial invasion into these fractures. On the other hand, non-red-fluorescing fractures contained necrotic tissue, debris, and irritants. CONCLUSIONS: This viable fluorescent technique can potentially quantify the depth of root fractures and be used as a risk indicator for root fractures with periodontal inflammation. CLINICAL SIGNIFICANCE: The auto-fluorescence technique can be used to detect depth and bacterial contamination of root fractures. It is postulated that the auto-fluorescence can be used as a risk indicator of deep fractures and can replace conventional fracture detection methods.

Cervical-thoracic necrotizing fasciitis of odontogenic origin in a diabetic patient: a case report.

Necrotizing fasciitis (NF) is a severe bacterial infection with rapid and aggressive progression. The infection generally affects individuals with comorbid conditions that lead to immunologic and microvascular deficiencies. It is characterized by necrosis of tissues, mainly in the extremities, trunk, and perineum, and is rarely found in the head and neck. This case report describes the course of NF in a 55-year-old man, highlighting diagnosis, surgical treatment, drug therapy, and supportive measures. The patient, who had chronic alcoholism, systemic arterial hypertension, a smoking habit, and decompensated diabetes (glucose level of 490 mg/dL), was admitted to the hospital with a volume increase in the cervical and thoracic areas with a duration of about 7 days. He presented with fever, dyspnea, and inflammatory signs bilaterally in the submandibular, submental, and superior thoracic regions as well as severe trismus. The patient underwent a surgical procedure to drain the infectious process and to place drains. The patient developed cutaneous necrosis in the cervical and superior thoracic regions, diagnosed as NF. Surgical debridement of all affected tissue was performed. After resolution of the infection, the patient underwent skin grafting with a satisfactory outcome.

Clonality of bacterial consortia in root canals and subjacent gingival crevices.

AIM: No oral niche can be considered to be segregated from the subjacent milieu because of the complex community behavior and nature of the oral biofilms. The aim of this study was to address the paucity of information on how these species are clonally related to the subjacent gingival crevice bacteria. METHODS: We utilized a metagenomic approach of amplifying 16S rDNA from genomic DNA, cloning, sequencing and analysis using LIBSHUFF software to assess the genetic homogeneity of the bacterial species from two infected root canals and subjacent gingival crevices. RESULTS: The four niches studied yielded 186 clones representing 54 phylotypes. Clone library comparisons using LIBSHUFF software indicated that each niche was inhabited by a unique flora. Further, 42% of the clones were of hitherto unknown phylotypes indicating the extent of bacterial diversity, especially in infected root canals and subjacent gingival crevices. CONCLUSIONS: We believe data generated through this novel analytical tool shed new light on understanding oral microbial ecosystems.

Case report: teeth and tonsils: the use of culture and sensitivity testing for antibiotic prescribing in dental infection.

This case report highlights the usefulness of bacterial culture and sensitivity testing in the prescribing of antibiotics for dental infections, demonstrated by the management of a 10-year-old child with a non-vital upper central incisor and, reportedly, associated recurrent tonsillitis.

Bacterial status in root-filled teeth exposed to the oral environment by loss of restoration and fracture or caries--a histobacteriological study of treated cases.

AIM: To describe histological and microbiological findings in teeth where root fillings had been exposed to caries and the oral environment for a prolonged period. METHODOLOGY: For inclusion in the study, only teeth with a follow-up period of 3 years or more and those that had been without proper restoration for at least a period of 3 months were considered. Some root fillings had been without restoration for several years. In all, 39 roots representing 32 teeth were examined by histology. RESULTS: The majority of the specimens were without a discernible periapical bone lesion as assessed by radiography. Osteolytic lesions were seen with five roots. Longitudinal tissue sections stained with a modified Brown/Brenn staining technique revealed presence of stainable bacteria in abundance at the canal entrance and in dentinal tubules but were absent mid-root and apically in all but two specimens. Soft tissue attached to the root tip and in apical ramifications displayed distinct inflammatory cell infiltrates, suggesting microbial exposure in 7 of the 39 roots examined. In all other specimens, inflammatory cell infiltrates were either nonexistent or sparse and then associated with extruded sealer material. CONCLUSIONS: Well-prepared and filled root canals resist bacterial penetration even upon frank and long-standing oral exposure by caries, fracture or loss of restoration.

Bacterial penetration of the root canal of intact incisor teeth after a simulated traumatic injury.

One of the aims in treating traumatised teeth is to maintain the vitality of the pulp or allow conditions favourable for pulp revascularisation. However, infection of the pulp and root canal system may prevent this. A number of pathways have been proposed that allow bacteria to invade the root canal system, however most of these pathways cannot account for pulp infection in teeth that did not sustain injury to the periodontal attachment. Enamel/dentine cracks have been proposed as a portal for bacterial invasion of seemingly intact teeth and the aim of this study was to determine if bacteria could invade the root canal system after a simulated traumatic episode. Twenty intact and sound upper central incisors were chosen and prepared. One tooth was selected as a sterility control and the external crown surface of the remaining 19 teeth was subjected to infection with Streptococcus gordonii in a bacterial microleakage model. Over 7 days samples of growth media from the root canal system were taken and tested for bacteria. Sixteen of the teeth did not demonstrate bacterial invasion over the time frame. These teeth were then prepared for testing in a pendulum impact device and were subjected to a blow which did not fracture the crowns or dislodge the tooth from its simulated alveolus. The teeth were then prepared and tested in the bacterial microleakage model. After impact seven of the teeth demonstrated bacterial invasion of the root canal system (P = 0.002). These teeth were then reprepared for testing in the bacterial microleakage model. The crowns of five teeth, selected at random, were coated with two layers of light cured unfilled resin, the remaining two were used as positive controls. All the teeth coated with resin did not demonstrate bacterial invasion (P = 0.00), while the positive controls demonstrated invasion. The results suggested that enamel/dentine infractions were pathways for bacterial invasion of the root canal system of traumatised teeth. The application of unfilled resin to the anatomical crown prevented infection.

The microbiologic approach in endodontics.

The results of an investigation of the microbiologic flora of gangrenous teeth are presented. The rationale of the concept of the microbiologic approach is discussed. A possible explanation for the small differences in the success of endodontically treated teeth obturated after positive and negative bacteriologic cultures is suggested.