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BACKGROUND: The antibacterial photodynamic therapy (aPDT) has been used in dentistry against oral microorganisms because of its excellent biocide effect. However, for carious lesions applications, there is little evidence that this therapy is safe for the pulp tissue. OBJECTIVE: This study evaluates the effects of an aPDT protocol on human pulp cells in vitro. METHODS: Pulp cells isolated from dental pulp were exposed to an aPDT protocol associating methylene blue (MB) at concentrations of 0.0125, 0.025 and 0.050mg/ml and red laser irradiation using a continuous-wave indium-gallium-aluminum-phosphide (InGaAlP) diode laser (λ=660nm, 40mW, 2.4J, 60J/cm(2) for 1min). Pre-irradiation time was 5min for each MB concentration. Cell viability was determined by MTT assay and activity of alkaline phosphatase was assessed by BCIP-NBT assay. Type of aPDT-induced cell death was assessed by flow cytometry. Data was statistically compared (ANOVA followed by Tukey' or Bonferroni's post hoc tests). RESULTS: aPDT was able to kill pulp cells in a dye concentration-dependent manner. The cellular viability was significantly reduced when used MB at 0.025 or 0.050mg/ml concentrations (p<0.0001). At these concentrations, aPDT-induced cell death occurred mostly by necrosis. Alkaline phosphatase activity was significantly reduced in all experimental groups (p<0.001). Pulp cells showed suitable viability when MB at 0.0125mg/ml was exposed to laser irradiation. CONCLUSIONS: aPDT with MB at 0.0125mg/ml may represent a low-risk therapy for restorative dentistry applications. aPDT protocol using concentrations above 0.025mg/ml of MB associating red laser irradiation may be harmful for dental pulp cells.

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Chemical hosts bind their guests by the same physical mechanisms as biomolecules and often display similarly subtle structure activity relationships. The cyclodextrins have found increasing application as inert, nontoxic carriers of active compounds in drug formulations. The present study was conducted to prepare inclusion complexes of chlorhexidine:ß-cyclodextrin (Cx:ß-cd), and evaluate their interactions with bacterial membrane through: scanning electron microscopy (SEM) and transmission electron microscopy (TEM); and measuring morphology alterations, roughness values, and cell weights by atomic force microscopy (AFM). It was found that the antimicrobial activity was significantly enhanced by cyclodextrin encapsulation. SEM analysis images demonstrated recognizable cell membrane structural changes and ultrastructural membrane swelling. By TEM, cellular alterations such as vacuolization, cellular leakage, and membrane defects were observed; these effects were enhanced at 1:3 and 1:4 Cx:ß-cd. In addition, AFM analysis at these ratios showed substantially more membrane disruption and large aggregates mixing with microorganism remains. In conclusion, nanoaggregates formed by cyclodextrin inclusion compounds create cluster-like structures with the cell membrane, possibly due to a hydrogen rich bonding interaction system with increasing surface roughness and possibly increasing the electrostatic interaction between cationic chlorhexidine with the lipopolysaccharides of Gram negative bacteria.

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Esta tese tem como objetivo avaliar a interacao de complexos supramoleculares de clorexidina (CX): ciclodextrinas (Cd) com celulas eucarioticas e procarioticas. Para estudar melhor a influencia na atividade antimicrobiana da CX apos a adicao de £/-Cd, £]-Cd e Hp-£]-Cd , foram realizados estudos in vitro aumentando a razao molar da ciclodextrina . A capacidade dos compostos na solubilizacao de ergosterol tambem foi investigada. O tamanho das particulas e potencial zeta foram determinados por espectroscopia por correlacao de fotons e anemometria laser Doppler usando um Zetasizer 3000 HS. As nanoparticulas resultantes estavam na gama de tamanho de 265-1451 nm, e com potencial zeta variando de -2 a 18 mV. A associacao destes compostos conduziu a um aumento do tamanho das nanoparticulas (493-1451 nm), com alteracao significativa dos potenciais zeta apos a formacao dos complexos supramoleculares. Os testes de atividade antimicrobiana dos mostraram que complexos de CX: £/-Cd foram mais eficientes para inibir o crescimento de Ca; CX: £]-Cd para Aa e CX: Hp-£]-Cd para Sm. A analise revelou valores de solubilizacao do ergosterol mais elevados com complexos £/-Cd 1:3 e 1:4. Foram utilizados Ensaios de proliferacao de diferentes tipos celulares para avaliar citotoxicidade in vitro. Os complexos supramoleculares de Hp-£]-Cd foram os menos citotoxicos para fibroblastos quando comparados aos outros compostos e a clorexidina pura. Os complexos de Ñ-Cd mostraram maior toxicidade para osteoblastos e fibroblastos quando comparados aos complexos Hp-£]-Cd. Dentre os compostos testados alcalina a 0,001%...

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Objetivo: Caracterizar os pacientes atendidos no programa de manutencao preventiva (MP) e relacionar as necessidades de tratamento apresentadas com os intervalos de retorno prescritos. Metodo: Foram coletados dados secundarios de prontuarios de pacientes da MP, no ano de 2008, relativos a idade, genero, e intervalo de tempo decorrido desde a ultima consulta. Registrou-se a presenca ou ausencia de alteracoes sistemicas, uso de medicamentos, dor ou desconforto bucal, desordem oclusal e lesoes de mucosa. Foram comparados os dois ultimos Indices Periodontais Comunitarios (CPI) e Indices de Placa Visivel (IPV). As variaveis necessidade de tratamento e tempo decorrido desde a ultima consulta foram comparadas pelo teste-t, com nivel de significancia de 5%. Resultados: A amostra consisti u de 115 individuos, 60,9% do genero feminino e 39,1% do masculino, com media de idade de 25,40 (ñ13,34) anos. A porcentagem dos que faziam uso regular de medicamentos (22,61%) foi maior que a observada para a presenca de alteracoes sistemicas (19,13%). Dos 67,83% que apresentaram necessidade de tratamento, 52,56% tinham necessidade de atencao primaria, 6,41% somente secundaria e 41,03% em ambos os niveis de atencao. O intervalo medio de tempo decorrido desde a ultima consulta (12,76 ñ 6,62 meses) apresentou baixa correlacao com as variaveis alteracoes sistemicas (r= 0,0174), uso de medicamentos (r= 0,0714), dor e desconforto bucal (r= 0,0357), lesoes de mucosa (r= 0,0357), necessidade de tratamento (r= 0,0368). Nao houve diferenca estatistica significativa entre os intervalos de retorno prescritos para individuos que tinham ou nao necessidade de tratamento (p=0,6958). Conclusao: Existe uma falta de sistematizacao na determinacao de intervalos de MP, ressaltando a necessidade de estudos prospectivos para estabelecer criterios baseados na classificacao de risco individual, que possam ser aplicados ao ensino da disciplina e a pratica profissional.

Objective: To characterize the patients enrolled in a preventive maintenance (PM) program, and to correlate their treatment needs with the prescribed and recall intervals. Method: Secondary data - age, gender and time interval elapsed since the last dental appointment - were collected from the charts of patients attending the PM program in 2008. The presence or absence of systemic alterations, use of medications, oral pain or discomfort, oclusal disorder and mucosal lesions was recorded. The last two Community Periodontal Indexes (CPI) and Visible Plaque Indexs (VPI) were compared. The variables treatment needs and time interval elapsed since the last dental appointment were compared by the t-test at 5% significance level. Results: The sample was composed by 115 individuals, 60.9% were females and 39.1% were males with mean age of 25.40 (ñ 13.34) years. The percentage of those who made regular use of medications (22.61%) was higher than that observed for the presence of systemic alterations (19.13%). From the 67.83% that had treatment needs, 52.56% needed primary attention, 6.41% only secondary attention and 41.03% needed both levels of attention. The mean time interval elapsed since the last appointment (12.76 ñ 6.62 months) had a low correlation with the variables systemic alterations (r= 0.0174), use of medications (r= 0.0714), oral pain and discomfort (r= 0.0357), mucosal lesions (r= 0.0357) and treatment needs (r= 0.0368). There was no statistically significant difference among the recall intervals prescribed for individuals who had or not treatment needs (p=0.6958). Conclusion: There is a lack of systematization in the determination of PM intervals, reinforcing the need for prospective studies to reestablish criteria based on the classification of individual risks that can be applied to the teaching of Integrated Clinic discipline and professional practice.

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The aim of this study was to observe the histopathological pulp response following direct pulp capping of mechanically exposed teeth in rats with a composite of beta-tricalcium phosphate-hydroxyapatite bioceramic (BC) and poly (glycolic)-poly (lactic acid) (PLGA) material or a calcium hydroxide [Ca(OH)2] material, compared to BC alone and a negative control of water. Pulp of the maxillary molars was exposed, followed by capping with the experimental material. The pulpal tissue response was assessed post-operatively at 1, 7, 14 and 30 d, followed by histological analysis. The Ca(OH)2 group exhibited severe acute inflammatory cell infiltration at day 14. However after 30 d, a new hard tissue with macro porous obliteration of the pulp chamber and a characteristic necrotic area had appeared. BC and Ca(OH)2 capping were associated with moderate inflammation and dentinal bridge similar. Meanwhile, in the BC/PLGA composite group, there was moderate inflammatory infiltrate and formation of a dense and complete dentinal bridge. In conclusion, the BC/PLGA composite material showed a large zone of tertiary dentin, and effectively reorganized the dentin-pulp complex.

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The aim of this study was to observe the histopathological pulp response following direct pulp capping of mechanically exposed teeth in rats with a composite of beta-tricalcium phosphate-hydroxyapatite bioceramic (BC) and poly (glycolic)-poly (lactic acid) (PLGA) material or a calcium hydroxide [Ca(OH)2] material, compared to BC alone and a negative control of water. Pulp of the maxillary molars was exposed, followed by capping with the experimental material. The pulpal tissue response was assessed post-operatively at 1, 7, 14 and 30 d, followed by histological analysis. The Ca(OH)2 group exhibited severe acute inflammatory cell infiltration at day 14. However after 30 d, a new hard tissue with macro porous obliteration of the pulp chamber and a characteristic necrotic area had appeared. BC and Ca(OH)2 capping were associated with moderate inflammation and dentinal bridge similar. Meanwhile, in the BC/PLGA composite group, there was moderate inflammatory infiltrate and formation of a dense and complete dentinal bridge. In conclusion, the BC/PLGA composite material showed a large zone of tertiary dentin, and effectively reorganized the dentin-pulp complex.

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Recent studies have shown that propolis has appreciable antibacterial, antifungal and antiviral actions, as well as cytostatic and antitumoral activity. In light of these studies, the antimicrobial activity of a new adhesive formulation containing propolis was evaluated in this in vitro study. Susceptibility of the oral strains tested (Candida albicans, Candida tropicalis, Streptococcus mutans, Staphylococcus aureus, Enterococcus faecalis, Actinomyces israelli, Actinobacillus actinomycetemcomitans) was evaluated using the agar diffusion method with different concentrations of propolis (5, 10, 15 and 20%). All of the assayed bacteria and fungi species were susceptible to propolis, with minimum inhibitory concentrations (MIC) ranging from 1.75 to 14.0 ãfg/ml. The positive results suggest that propolis in this sustained release formulation should be further tested as an alternative therapy of infectious conditions of the oral cavity, such as denture stomatitis and periodontitis. However, in vivo studies of the effect of this new adhesive formulation of propolis are needed to determine its possible effects on the oral mucosa.

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