A metagenomic study of patients with alveolar osteitis after tooth extraction. A preliminary case-control study.

OBJECTIVE: To identify the microbiome in sockets with alveolar osteitis and compare it with a control group using metagenomic techniques. MATERIALS AND METHODS: A case-control study was conducted in subjects that had undergone a tooth extraction. Microbiological samples were taken from the sockets of 10 patients with dry socket after tooth extraction (AO group) and 10 patients in whom exodontia resulted in no postoperative complications (control group). Bacterial DNA was isolated, and the 16S rRNA gene was amplified and sequenced. Multiplexed tag-encoded sequencing of DNA from the samples was performed, and the reads were processed by Metagenomic Rapid Annotation. RESULTS: A total of 151 different species were found: 55 bacteria were only found in the AO group, 51 were specific to the control group, and 45 were common to both groups. The most frequently found genera in both groups were Prevotella. Prevotella nanceiensis, Actinomyces odontolyticus, Treponema maltophilum, Veillonella dispar, Tannerella forsythia, and Leuconostoc mesenteroides were found in several patients with alveolar osteitis, with an abundance greater than 0.5%, and were absent in all the control group samples. CONCLUSIONS: Patients who develop alveolar osteitis after dental extractions might have a different microbiota from that of patients without postoperative complications. Since this is a preliminary report, further research is needed to assess whether bacteria play an important role in the etiology of dry socket. CLINICAL RELEVANCE: This study seems to indicate that bacteria may play an important role in the alveolar osteitis etiology. Thus, new prevention and treatment strategies should be considered.

Microbiota Analysis of Biofilms on Experimental Abutments Mimicking Dental Implants: An In Vivo Model.

BACKGROUND: The microbiota colonizing dental implants has been said to be similar to the microbiome surrounding teeth. In the absence of inflammation, a biofilm with pathologic bacteria can cover implant surfaces exposed to the oral cavity, for example, due to a remodeling process. The aim of the present study is to identify microbiota surrounding exposed dental implants in patients with and without a history of periodontitis through a deep-sequencing approach. METHODS: An experimental abutment with the same surface and structure as a commercially available dental implant was used. Bacterial DNA was isolated, and the 16S ribosomal RNA gene was amplified and sequenced. Multiplexed tag-encoded sequencing of DNA from the samples was performed, and the reads were processed by metagenomic rapid annotation. RESULTS: A wide variety of bacteria, 96 species, were identified. The most frequently found bacteria were Fusobacterium nucleatum and Prevotella denticola. Some species generally associated with periodontitis were found to a greater extent in patients without a history of periodontitis. Some bacteria that have never been described as part of the oral microbiome were identified in the present sample. CONCLUSIONS: Analysis of data suggests that the bacteria surrounding exposed dental implants form a diverse microbiome regardless of the periodontal profile of patients. Further research is needed to clarify the role of these microorganisms in the oral environment.