Plasmacytoma in the oral cavity: a case report

The plasma cell neoplasms may present in soft tissue as extramedullary plasmacytoma (EMP), in bone as a solitary plasmacytoma of bone (SPB), or as part of the multifocal disseminated disease multiple myeloma (MM). The EMP is rare, comprising around 3% of all plasma cell neoplasm. The majority (80%) occurs in the head and neck region. In this study we report a case of a man, 70 years old, melanoderm, with a lesion of the oral cavity. Upon physical examination, a lesion was found that extended throughout the posterior upper alveolar ridge, as far as the maxillary tuber on the left side, extending towards the palate. Radiographic examination, complementary laboratory exams were performed. Based on the conclusive symptoms of plasmacytoma, the patient was referred to the hematology service for treatment with local radiotherapy. The patient responded satisfactorily to the treatment, and after 15 months, all clinical symptoms of the lesion in the oral cavity had disappeared.

How do titanium and Ti6A14V corrode in fluoridated medium as found in the oral cavity? an in vitro study

The purpose of this work was to evaluate the corrosion of commercially pure (CP) titanium and Ti6Al4V in vitro at different F- concentrations regularly found in the oral cavity by using different electrochemical tests and surface analysis techniques. electrochemical impedance spectroscopy (EIS), open circuit potential (OCP) and potentio-dynamic polarization tests were associated to advanced characterization techniques such as SEM, EDS, AFM, ICP-MS and XPS. OCP tests revealed a higher reactivity of both CP titanium and Ti6Al4V at 12,300 ppm F- concentration than that recorded at 227 ppm F-. Also, a significant decrease of the corrosion resistance of both materials was noticed by EIS in fluoride solutions. Material loss caused by corrosion was noticed on titanium surfaces by SEM and AFM in the presence of high F- concentration. CP titanium degraded by pitting corrosion while Ti6Al4V suffered from general corrosion showing micro-cracks on surface. Furthermore, a high release of metallic ions from the test samples after immersion at high F concentrations was detected by ICP-MS, that can be potentially toxic to oral tissues. (C) 2014 Elsevier B.V. All rights reserved.

Autogenous bone grafts contamination after exposure to the oral cavity

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Species diversity of yeast in oral colonization of insulin-treated diabetes mellitus patients

The aim of this study was to investigate oral yeast colonization, antifungal susceptibility and strain diversity in insulin-dependent diabetes mellitus patients (175), as well as to evaluate the influence of dental prostheses. Oral rinse samples were cultured on selective media, in order to isolate, count and identify the yeasts recovered. More than half of the diabetic subjects (53%) carried significant amounts of Candida cells in the buccal cavity and these organisms were recovered at higher densities in diabetics wearing dentures. A total of 93 yeast strains were isolated from these patients, including: Candida spp. (n = 89); Pichia (n = 02); Trichosporon (n = 1), and Geotrichum (n = 1). C. albicans represented 56% of these strains, non-albicans Candida 39.8%, and other genera of yeast 4.3%. C. albicans was prevalent, followed by C. parapsilosis, C. tropicalis, C. glabrata, C. krusei, C. rugosa and C. guilliermondii. Agar disk-diffusion tests of the susceptibility of non-albicans Candida and other genera of yeast to fluconazole showed resistance in 21.9%, mainly in C. rugosa (100%), C. glabrata (57%) and C. krusei (50%). Local oral factors, such as the presence of dentures, in association with diabetes, seemed to have the effect of increasing the amount and variety of Candida species in the oral cavities, mainly those with lower drug susceptibilities.

Effects of eating disorders on oral fungal diversity

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Oral microbial colonization in patients with systemic lupus erythematous: correlation with treatment and disease activity

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Genetic diversity and antifungal susceptibility testing of Trichosporon asahii isolated of Intensive Care Units patients

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Oral microbiota of Brazilian captive snakes

The present work aimed to determine the oral microbiotic composition of snakes from Sao Jose do Rio Preto city, São Paulo State, Brazil. Ten snake species, comprising the families Boidae, Colubridae, Elapidae and Viperidae, were submitted to microbiological examination of their oral cavity, which indicated positivity for all buccal samples. Gram-negative bacilli, gram-negative cocci bacilli, gram-positive bacilli and gram-positive cocci were isolated from the snakes. Among isolated bacterium species, the occurrence of coagulase-negative staphylococci in the buccal cavity of Crotalus durissus (Viperiade), Eunectes murinus (Boidae), Mastigodryas bifossatus (Colubridae) and Bacillus subtilis, common to oral cavity of Bothrops alternatus (Viperidae) and Phalotris mertensi (Colubridae), was detected. It was observed higher diversity of isolated bacteria from the oral cavity of Micrurus frontalis (Elapidae) and Philodryas nattereri (Colubridae), as well as the prevalence of gram-positive baccillus and gram-positive cocci. The composition of the oral microbiota of the studied snakes, with or without inoculating fangs, is diverse and also related to the formation of abscesses at the bite site in the victims of the ophidian accidents, and to pathogenic processes in the snakes that host these microorganisms.

Antimicrobial activity of Uncaria tomentosa against oral human pathogens

Uncaria tomentosa is considered a medicinal plant used over centuries by the peruvian population as an alternative treatment for several diseases. Many microorganisms usually inhabit the human oral cavity and under certain conditions can become etiologic agents of diseases. The aim of the present study was to evaluate the antimicrobial activity of different concentrations of Uncaria tomentosa on different strains of microorganisms isolated from the human oral cavity. Micropulverized Uncaria tomentosa was tested in vitro to determine the minimum inhibitory concentration (MIC) on selected microbial strains. The tested strains were oral clinical isolates of Streptococcus mutans, Staphylococcus spp., Candida albicans, Enterobacteriaceae and Pseudomonas aeruginosa. The tested concentrations of Uncaria tomentosa ranged from 0.25-5% in Müeller-Hinton agat. Three percent Uncaria tomentosa inhibited 8% of Enterobacteriaceae isolates, 52% of S. mutans and 96% of Staphylococcus spp. The tested concentrations did not present inhibitory effect on P. aeruginosa and C. albicans. It could be concluded that micropulverized Uncaria tomentosa presented antimicrobial activity on Enterobacteriaceae, S. mutans and Staphylococcus spp. isolates.

Microbial distribution in the root canal system after periapical lesion induction using different methods

The aim of this study was to evaluate the microbial distribution in the root canal system after periapical lesion induction in dogs' teeth using different methods. Fifty-two root canals were assigned to 4 groups (n=13). Groups I and II: root canals were exposed to the oral cavity for 180 days; groups III and IV: root canals were exposed for 7 days and then the coronal openings were sealed for 53 days. The root apices of groups I and III were perforated, while those of groups II and IV remained intact. After the experimental periods, the animals were euthanized and the anatomic pieces containing the roots were processed and stained with the Brown & Brenn method to assess the presence and distribution of microorganisms. The incidence of microorganisms at different sites of the roots and periapical lesions was analyzed statistically by the chi-square test at 5% significance level. All groups presented microorganisms in the entire root canal system. A larger number of microorganisms was observed on the root canal walls, apical delta and dentinal tubules (p<0.05), followed by cementum and cemental resorption areas. In spite of the different periods of exposure to the oral environment, the methods used for induction of periapical periodontitis yielded similar distribution of microorganisms in the root canal system.

In vitro susceptibility of oral Candida albicans strains to different pH levels and calcium hydroxide saturated aqueous solution

Candida albicans is present in the oral cavity and in the whole digestive tract of humans and other animals, being frequently related to endodontic treatment failure. The present study determined the incidence of C. albicans in the oral cavity and the susceptibility of isolates to different pH values and saturated calcium hydroxide aqueous solution at pH 12.5. Sixty-five patients attending the Endodontic Clinic at the Sagrado Coração University participated in the study. The collected samples were cultivated in selective media for C. albicans and the isolates were tested in terms of resistance to both alkaline pH and saturated aqueous solution of calcium hydroxide. In relation to time variables, yeast viability was assessed by the Sabouraud's agar culture and fluorescein diacetate and ethidium bromide fluorescent staining method. Results from the different pHs and experimental times, including those from different techniques measuring fungal viability, were compared using the chi-square and Fisher's exact tests (α=0.05). The yeasts became completely inviable after 48 h of contact with the calcium hydroxide solution. On the other hand, when exposed to the alkaline culture broth, the yeasts were found to be viable at pHs 9.5 and 10.5 for up to 7 days. In conclusion, C. albicans can only be completely inhibited by direct contact with saturated calcium hydroxide aqueous solution after 48 h of exposure.

Daily biofilm control and oral health: Consensus on the epidemiological challenge-Latin American Advisory Panel

Our understanding of dental plaque biofilm has evolved since the nonspecific plaque hypothesis that considered plaque as a nonspecific mass of native microorganisms that, because of lack of oral hygiene, builds up in proportions great enough to overcome the host resistance threshold and affect the tooth structure and tooth supporting tissues. A great diversity of microorganisms-over 700 species-was detected in the oral cavity, and evidence shows that the investigation of specific microorganisms or associations of microorganisms as etiological agents for periodontal diseases and caries is not a simplistic approach. Although clinical evidence shows that oral mechanical hygiene is fundamental to prevent and control caries and periodontal disease, it is important to highlight that optimal control is not achieved by most individuals. Thus the complementary use of chemotherapeutic agents has been investigated as a way to overcome the deficiencies of mechanical oral hygiene habits, insofar as they reduce both plaque formation and gingival inflammation, and represent a valid strategy to change the biofilm and maintain dental and periodontal health. The role of the dental professional is to monitor patients and offer them the best recommendations to preserve oral health throughout their life. With this in mind, chemical control should be indicated as part of daily oral hygiene, together with mechanical procedures, for all individuals who present supragingival and/or subgingival biofilm, taking into account age, physical and/or psychological limitations, allergies, and other factors.

Implant-abutment gap versus microbial colonization: Clinical significance based on a literature review

Microorganisms from the oral cavity may settle at the implant-abutment interface (IAI). As a result, tissue inflammation could occur around these structures. The databases MEDLINE/PubMed and PubMed Central were used to identify articles published from 1981 through 2012 related to the microbial colonization in the implant-abutment gap and its consequence in terms of crest bone loss and osseointegration. The following considerations could be put forward, with respect to the clinical importance of IAI: (a) the space present at the IAI seems to allow bacterial leakage to occur, in spite of the size of this space; (b) bacterial leakage seems to occur at the IAI, irrespective of the type of connection. More studies are necessary to clarify the relationship between leakage at IAI and abutment connection designs; (c) losses at the peri-implant bone crests cannot be related to the IAI size, since few studies have shown no relationship. Also, the microbial leakage at the IAI cannot be related to the bone crest loss, since there are no articles reporting this relationship; remains controversial the influence of the IAI position on the bone crest losses. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 101B: 1321-1328, 2013. Copyright © 2013 Wiley Periodicals, Inc.

Identificação de patógenos da cavidade bucal no lavado broncoalveolar de pacientes sob ventilação mecânica

Pós-graduação em Odontologia Restauradora - ICT