Analysis of microbial communities of ocular prostheses and anophthalmic sockets using 16S rRNA gene sequencing

Ocular prostheses are liable to host microbial adhesion, which can favor conjunctival inflammation. Knowing the microbiota of the ocular prosthesis and anophthalmic socket is important for predicting infection-related pathogens. This study evaluated the microbiota of the prostheses and anophthalmic sockets of six individuals by 16S rRNA sequencing. The microbial abundance and diversity were analyzed using the Operational Taxonomic Units at the genus level. Forty-seven phyla, capturing 1,258 named genera, were recorded in the sample set. In both sites, the most frequent genera were Fusobacterium, Staphylococcus, Prevotella, and Streptococcus. The microbial abundance was higher for the anophthalmic socket than for the prosthesis. Alpha diversity showed no significant differences in bacterial richness or diversity between sites. Although the microbial abundance in the anophthalmic socket was higher, both sites had similar microbiota with high diversity and low dominance among the genera.

Desenvolvimento de um Produto à Base de Óleo Essencial de Lippia Sidoides como Auxiliar para Prevenção e Tratamento da Estomatite Protética

O presente estudo tem como objetivo apresentar os resultados preliminares relacionados a atividade antimicrobiana de uma solução a base de óleos essenciais de Lippia sidoides (OELS) frente à microrganismos envolvidos na formação de biofilme sobre superfícies protéticas. Após obtenção da planta e identificação taxonômica, extração dos OELS e confirmação dos seus constituintes por meio de cromatografia, foram obtidas soluções iniciais em três diferentes solventes - Twin 80, Lauril sulfato de sódio (LSS) e álcool. A atividade antimicrobiana das mesmas foi testada por meio da determinação da concentração inibitória (CIM) e bactericida/fungicida mínimas (CBM/CFM) frente aos microrganismos Staphylococcus aureus (S. aureus, gram positivo), Pseudomonas aeruginosa (P. aeruginosa, gram negativo) e Candida albicans (C. albicans, levedura), separadamente. Após realização do teste de microdiluição em caldo, em duplicata, o solvente LSS demonstrou o melhor resultado com MIC de 1,25mg/ml para P. aeruginosa, 0,039mg/ml para S. aureus e 0,078mg/ml para C. albicans. Os resultados para CBM/CFM encontrados foram: 1,25mg/ml para P. aeruginosa, 0,039mg/ ml para S. aureus e 0,156mg/ml para C. albicans. A solução de OELS em LSS mostrou-se atividade antimicrobiana efetiva frente aos microrganismos testados. Sua efetividade será testada em biofilmes mistos, seguido da determinação do tempo regime de utilização mais adequado, toxicidade e efeito sobre os materiais utilizados em próteses dentárias, como resina acrílica.Palavras-chave: Prótese Dentária. Estomatite sob Prótese. Lippia

Efeito do Uso Contínuo de um Protocolo de Polimento Mecânico na Adesão de Biofilme Multiespécie em Dentes Artificiais de Resina Acrílica

Foi avaliado o efeito de um protocolo de polimento mecânico frequente na adesão de biofilme em dentes artificiais de resina acrílica. Incisivos centrais superiores (n60) foram divididos em dois grupos: imersão em água destilada (AD) e café (CF) e estes, subdivididos em (n10): apenas imersão, associação com polimento quinzenal (POL1) e mensal (POL2). O polimento foi realizado por meio de motor manual (3000 rpm) com roda de feltro e pasta de óxido de alumínio, em intervalos de tempo simulando 15 e 30 dias de consumo diário de café. Ao final da simulação de 2 anos, foram realizados testes de adesão de biofilme multiespécie de Candida albicans (Ca) e Streptococcus mutans (Sm), contagem de unidades formadoras de colônias (UFC) e microscopia de fluorescência. Os maiores valores de UFC foram observados nos grupos imersos em café tanto para Ca (CF5,966±0,035 AD5,175±0,141 p0,006) quanto para Sm (CF5,673±0,047 AD4,762±0,140 p0,002). Ambos os regimes de polimento, quando associados à imersão em AD, não alteraram a adesão de Ca (p0,783) e Sm (p0,058). Já para os grupos imersos em café, o POL1 (Ca5,326±0,037 Sm4,204±0,0268) e o POL2 (Ca5,442±0,036 Sm 4,895±0,132) apresentaram redução significativa de ambos os microrganismos (p<0,001), sendo que para o Sm essa redução foi maior no POL1. A microscopia de fluorescência evidenciou imagens em conformidade com os resultados quantitativos obtidos no teste de formação de biofilme. O polimento testado, quando realizado de forma frequente, reduz a adesão de biofilme, sendo a frequência quinzenal mais efetiva.Palavras-chave: Dente Artificial. Polimento Dentário. Biofilmes.

A randomised trial of a simplified method for complete denture fabrication: patient perception and quality

Complete denture fabrication involves a series of complex technical procedures. Nevertheless, simplified methods may be as effective as conventional ones albeit the lesser use of time and resources, without disadvantage for the patient. This study compared a simplified method for complete denture fabrication to a conventional protocol in terms of oral health-related quality of life (OHRQoL), patient satisfaction and denture quality. Forty-two edentulous patients requesting treatment with complete dentures were randomly allocated into two study groups. Group S received dentures fabricated by a simplified method and Group C received conventionally fabricated dentures. Before interventions and after three and 6 months following insertion, OHRQoL and patient satisfaction were analysed by specific instruments. A prosthodontist assessed denture quality 3 months after delivery. Groups presented no difference for OHRQoL, denture quality and general satisfaction. Differences regarding patient satisfaction with some aspects of the dentures were found after 3 months (S > C), but were insignificant at 6 months. It was concluded that the simplified method is able to produce dentures of a quality comparable to those produced by the conventional method, influencing OHRQoL and patient satisfaction similarly.

Effects of the domestic use of a disclosing solution on the denture biofilm: a preliminary study

To investigate the effect of the home use of a disclosing agent on the microbial composition of denture biofilm, by means of a cross-over randomized clinical trial. Two interventions were tested during 7 days each: (I) oral and denture hygiene instructions and (II) instructions associated with the home use of a disclosing agent (1% neutral red). Eleven participants with visible biofilm deposits over their maxillary complete dentures were randomly assigned to one of the two sequences of interventions: (i) I followed by II, and (ii) II followed by I. A washout period of 7 days was established. After each intervention, samples of denture biofilm were evaluated by DNA checkerboard hybridization for the detection of Candida spp. and 17 bacterial species. Counts were low for all the tested species, and no significant difference was found between the tested interventions (Wilcoxon test, P > 0.05). The home use of a disclosing agent does not remarkably change the composition of denture biofilm.

Effects of mechanical and chemical methods on denture biofilm accumulation

The aim of this study was to quantify biofilm on the internal surface of upper complete dentures following six possible cleansing methods. Thirty-six edentulous subjects were submitted to a time-series trial and dentures were cleansed according to six methods: (i) rinsing with water; (ii) soaking in an alkaline peroxide solution (Bonyplus); (iii) brushing with dentifrice (Dentu-Creme) and soft Johnson and Johnson's toothbrush; (iv) combination between soaking and brushing according to methods 2 and 3; (v) brushing with dentifrice (Dentu-Creme) and soft Oral B toothbrush; (vi) combination between soaking and brushing according to methods 2 and 5. Each method was randomly used throughout 21 days. Denture biofilm was disclosed by 1% neutral red solution and quantified by means of digital photos taken from the internal surface. The six methods presented significant differences in percentage of biofilm coverage (repeated measures anova, P < 0.0001). Method 1 showed the highest values, 2 was intermediate and other results were the lowest. The most efficacious approach was 6. Biofilm tended to accumulate predominantly over specific zones of the denture base, but this pattern did not change regardless of the method employed. It can be concluded that brushing alone was more effective than the chemical method employed. The best results were obtained by a combination of methods.