No abstract

Multiple-displacement amplification (MDA) has been used to uniformly amplify bacterial genomes present in small samples, providing abundant targets for molecular analysis. The purpose of this investigation was to combine MDA and checkerboard DNA-DNA hybridization to examine the microbiota of endodontic infections. Sixty-six samples were collected from teeth with endodontic infections. Nonamplified and amplified samples were analyzed by checkerboard DNA-DNA hybridization for levels and proportions of 77 bacterial taxa. Counts, percentages of DNA probe counts, and percentages of teeth colonized for each species in amplified and nonamplified samples were computed. Significance of differences for each species between amplified and nonamplified samples was sought with Wilcoxon signed-rank test and adjusted for multiple comparisons. The amount of DNA in the samples ranged from 6.80 (؎ 5.2) ng before to 6.26 (؎ 1.73) g after MDA. Seventy of the 77 DNA probes hybridized with one or more of the nonamplified samples. All probes hybridized with at least one sample after amplification. Most commonly detected species at levels of >10 4 in both amplified and nonamplified samples were Prevotella tannerae and Acinetobacter baumannii at frequencies between 89 and 100% of samples. The mean number of species at counts of >10 4 in amplified samples was 51.2 ؎ 2.2 and in nonamplified samples was 14.5 ؎ 1.7. The endodontic microbiota was far more complex than previously shown, although microbial profiles at teeth with or without periradicular lesions did not differ significantly. Species commonly detected in endodontic samples included P. tannerae, Prevotella oris, and A. baumannii.The microbiology of endodontic infections has been studied for many years (4, 47, 58). However, the association between specific microorganisms found in root canals and the symptoms of endodontic infections is poorly understood. Early studies of the endodontic microbiota indicated a predominance of aerobic and facultative bacterial species (16). This conclusion was questioned by the development of anaerobic culturing techniques which clarified the etiopathogenesis of endodontic infections by demonstrating the common occurrence of obligate anaerobic bacteria (4, 23, 30). Nevertheless, culture-based techniques have limitations, such as the difficulty in detecting fastidious anaerobic microorganisms and moderate sensitivity and specificity (44).Recently, molecular biology techniques have provided a more cost-effective, specific, and sensitive method to evaluate the microbiological profiles of oral pathologies, including endodontic and periodontal infections (37,38,44,(52)(53)(54). 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).Checkerboard DNA-DNA hybridization is a high-throughput method to analyze large numbers of DNA samples by use of a wide range of...

Denture stomatitis presents as a chronic disease in denture-bearing patients, especially under maxillary prosthesis. Despite the existence of a great number of antifungal agents, treatment failure is observed frequently. Propolis, a natural bee product, possesses well-documented antifungal and anti-inflammatory activities. The purpose of this study was to evaluate the clinical efficacy of a new Brazilian propolis gel formulation in patients diagnosed with denture stomatitis. Thirty complete-denture wearers with denture stomatitis were enrolled in this pilot study. At baseline, clinical evaluation was performed by a single clinician and instructions for denture hygiene were provided. Fifteen patients received Daktarin (Miconazole gel) and 15 received Brazilian propolis gel. All patients were recommended to apply the product four times a day during one week. Clinical evaluation was repeated by the same clinician after treatment. All patients treated with Brazilian propolis gel and Daktarin had complete clinical remission of palatal edema and erythema. This new Brazilian propolis gel formulation had efficacy comparable to Daktarin and could be an alternative topical choice for the treatment of denture stomatitis.

Fatigue resistance of used instruments was reduced, but no significant change was observed amongst the instruments used for shaping the canals of five and eight molars. Operator experience affected the occurrence of fracture and plastic deformation during shaping.

Mothers' SOC of children/adolescents with MPS was associated with dental caries experience in their children. Improving mothers' SOC should contribute to a better quality of life for their children.