Avaliação da microbiota de dentes decíduos necrosados utilizando a reação da polimerase em cadeia

Abstract

This study aims to evaluate the microbiota of necrotic primary teeth through the technique of polymerase chain reaction (PCR), whereas primary endodontic infections, comparing the microbiota of necrotic caries and dental trauma. This study also evaluated the bacterial viability in three transport medias (Reduced to Fluid Transport , Tris - EDTA and Viability Medium Göteborg anaerobically III), simulating the conditions of carriage of the endodontic microbiota from the clinic to the laboratory, considering the time elapsed between the collection and processing. This clinical study involved 43 children from two to nine years of age, who sought care at the Pediatric Dentistry Clinic of Federal University of Ceará. They might present necrosis in primary teeth. Healthy patients formed a sample with 47 necrotic channels. Were included teeth with at least two-thirds of root and able to be restored. Patients who were making use of antibiotic therapy or those who did the last three months before the start of the study, and those with inappropriate behavior for the research were excluded. For microbiological collection after infiltration anesthesia and absolute isolation, disinfection of the operative field to open the coronary cavity was performed. The collection was made from the introduction of three absorbent paper cones in the wider channel for one minute each. The storage and transport of these listed microorganisms were performed using the VMGA III selected from a laboratory experiment. In this experiment we evaluated the feasibility of a strain of Porphiromonas gingivalis , stored in fluid Reduced to transport (RTF), TE and Viability Medium Göteborg anaerobically, VMGA III. In a laboratory under anaerobic conditions, were inoculated in eppendorffs® for periods of one hour, two and four hours. Then inoculated in Petri dishes in these different times, with Fastidious Anaerobe Agar (FAA) enriched. Last 72 hours counting of bacterial colonies was performed. This evaluation showed that the VMGAIII was the means of transportation that allowed an upper storage to four hours of processing Porphiromonas gingivalis in culture when compared with the RTF and the TE. Thus, microbiological samples were introduced in eppendorffs® with VMGA III for further processing of the samples. DNA of bacterial samples for subsequent implementation of the technique of polymerase chain reaction (PCR) followed by eletrofores, through which was extracted identified the presence of the following bacteria: Fusobacterium nucleatum, Parvimona microns, Porphyromonas endodontalis, Porphyromonas gingivalis, Dislister pneumonsites, alocis Filifactor, Treponema denticola, Tannerella forsythia, Enterococcus faecalis, Streptococcus mitis, Streptococcus mutans, Streptococcus sanguis, Prevotela nigrescens, Actinomyces naeslundi and Enterococcus faecalis. Then identify a microbial organisms comprising predominantly anaerobic Gram negative for the test. The most common were: Prevotella nigrescens (17.92%), Parvimona micra (16.24%) and Actinomyces naeslundi (12.88 %). The less frequent were Filifactor alocis (1.12 %), Streptococcus mitis (1.12%), Enterococcus faecalis (0.56 %) and Streptococcus mutans (0.56 %). Whereas the cause of pulp necrosis, caries was associated with Parvimona micra (p = 0.036), and trauma, Streptococcus mitis (0.022). Thus it is concluded from clinical samples of necrotic primary teeth, the methodology involved in the bacterial collection and storage process as the means of transport, can influence our findings. The sample had a higher frequency of the Gram negative anaerobic bacteria test. The cause of necrosis may influence the establishment of the microbiota, where the decay is associated with positive and negative anaerobic bacteria to the Gram test, as Parvimona micra and Treponema denticola, and were associated with the trauma and positive facultative bacteria to the Gram test such as forsythia Tanarella, Streptococcus mitis and Streptococcus sanguis.