The influence of implant surface roughness on decontamination by antimicrobial photodynamic therapy and chemical agents: A preliminary study in vitro.

BACKGROUND: The aim of this preliminary study was to analyze the effectiveness of three different protocols of decontamination on five commercial moderate rough implants. MATERIAL AND METHODS: The types of implants investigated were: Neoporos Drive CM (CM; Neodent®), Drive CM Acqua (ACQ; Neodent®), SLActive (SLA; Straumann®), Osseotite (OT; Biomet 3i®) and Nanotite (NT; Biomet 3i®). Implant surface properties (n = 2/type of implant; control groups) were analyzed by scanning electron microscopy (SEM) images to determine surface roughness parameters (SRP) and energy disperse X-ray spectrometry to determine the chemical composition. Implants were then inoculated with Aggregatibacter actinomycetencomitans in vitro (n = 6/type of implant;experimental groups) and the contaminated areas were determined in SEM images (500x magnifications). Decontamination of implants was performed in duplicate by three protocols: antimicrobial photodynamic therapy (aPDT), EDTA associated with citric acid (EDTA + CA) and 0.12 % chlorhexidine (CHX). The remaining contaminated area (rCtA) was determined in SEM images (500x magnifications). All quantitative analysis through SEM images were analyzed in ImageJ® software for two-dimensional parameters. RESULTS: No significant differences were found in SRP among implants (control group), except for Rv (lowest valley) between SLA vs. OT (p=0.0031; Kruskal Wallis post hoc Dunn). NT implants showed highest contaminated area vs. ACQ implants (68.19 % ± 8.63 % and 57.32 % ± 5.38 %, respectively; p = 0.0016, Tukey's test). SRP after decontamination showed statistical difference for Ra (arithmetical mean deviation) for all decontamination groups when compared to control (p < 0.05; ANOVA with post-hoc Tukey's multiple comparisons test), only CM implants showed statistical difference when compared decontamination protocols to control with highest modification of SRP for EDTA + AC group. For decontamination analysis, for applicability of different protocols in the same type of implant, only SLA showed statistical significant difference for aPDT vs. EDTA + CA (p = 0.0114; ANOVA with post-hoc Tukey's multiple comparisons test) with lowest rCTA for aPDT, however for ACQ implants the aPDT showed lowest rCTA with no statistical difference (p > 0.05; ANOVA with post-hoc Tukey's multiple comparisons test). No statistical difference was observed between the decontamination protocols at other implant types. CONCLUSION: It can be suggested that the chemical-physical characteristics of dental implants can be effected by the process of contamination and decontamination by aPDT and chemical agents.

Candida albicans-Cell Interactions Activate Innate Immune Defense in Human Palate Epithelial Primary Cells via Nitric Oxide (NO) and ß-Defensin 2 (hBD-2).

The presence of Candida albicans in the biofilm underlying the dental prosthesis is related to denture stomatitis (DS), an inflammatory reaction of the oral mucosa. The oral epithelium, a component of the innate immune response, has the ability to react to fungal invasion. In this study, we evaluated the in vitro effect of viable C. albicans on the apoptosis, nitric oxide (NO) production, and ß-defensin 2 (hBD-2) expression and production of human palate epithelial cells (HPECs). We further determined whether or not these effects were correlated with fungal invasion of epithelial cells. Interaction between HPEC primary culture and C. albicans was obtained through either direct or indirect cell-cell contact with a supernatant from a hyphal fungus. We found that the hyphae supernatants were sufficient to induce slight HPEC apoptosis, which occurred prior to the activation of the specific mechanisms of epithelial defense. The epithelial defense responses were found to occur via NO and antimicrobial peptide hBD-2 production only during direct contact between C. albicans and HPECs and coincided with the fungus's intraepithelial invasion. However, although the hBD-2 levels remained constant in the HPEC supernatants over time, the NO release and hBD-2 gene expression were reduced at a later time (10 h), indicating that the epithelial defense capacity against the fungal invasion was not maintained in later phases. This aspect of the immune response was associated with increased epithelial invasion and apoptosis maintenance.

Blue photosensitizers for aPDT eliminate Aggregatibacter actinomycetemcomitans in the absence of light: An in vitro study.

The main treatment of periodontal disease is the mechanical removal of supra and subgingival biofilm. Adjuvant therapies as antimicrobial photodynamic therapy (aPDT) may offer improved clinical and microbiological results. The aim of this in vitro study was to evaluate the effect of toluidine and methylene blue dyes, associated with red laser and LED, on elimination of a suspension of Aggregatibacter actinomycetemcomitans (A.a). Experimental groups (n = 29) consisted of positive (broth) and negative (gentamicin) controls, three different dyes concentrations (0.05; 0.1; 10 mg/ml) alone or associated with laser (660 nm) at two power settings (70 and 100 mW) and LED (627 ±â€¯10 nm). Bacterial suspension received all treatments, and after serial dilutions they were cultured for 24 h in petri dishes for colony forming unit counts. Data were analyzed by ANOVA complemented by Tukey's test (p < 0.05). The results showed that both dyes, at a concentration of 10 mg/ml, alone or associated with laser and LED, caused 100% of death similar to the negative control (p > 0.05). It can be concluded that blue dyes for aPDT, at high concentration (10 mg/ml), are capable of eliminating A.a without adjuvant use of light sources.

Atividade antimicrobiana de própolis de Apis mellifera obtidas em três regiões do Brasil / Antimicrobial activity of Apis mellifera propolis from three regions of Brazil

As propriedades biológicas da própolis de Apis mellifera são amplamente relatadas sendo comuns variacões nas mesmas em funcão da região onde foram produzidas. A acão antimicrobiana de própolis obtidas em três regiões do Brasil (Botucatu-SP, Mossoró-RN e Urubici-SC) foi investigada sobre linhagens isoladas de infeccões clínicas humanas (Staphylococcus aureus, Escherichia coli, Enterococcus sp, Pseudomonas aeruginosa e Candida albicans). Foram preparados extratos alcoólicos de própolis (EAP) e determinada a Concentracão Inibitória Mínima (CIM) seguida do cálculo da CIM90 por cento. A própolis de Botucatu foi a mais eficiente sobre S. aureus (0,3 por centov/v), Enterococcus sp (1,1 por centov/v) e C. albicans (2,1 por cento v/v). Para E. coli, a própolis eficiente foi de Urubici (7,0 por centov/v) e para P. aeruginosa a de Mossoró (5,3 por centov/v). Os resultados mostram maior sensibilidade das bactérias Gram positivas e levedura em relacão às Gram negativas. É possível concluir que, para os microrganismos testados e amostras de própolis testadas, há diferencas na atividade antimicrobiana em funcão do local de producão e que isso se explica pela diferenca de composicão química da própolis.

Incidencia e perfil de resistencia de bacterias isoladas de lesoes de pacientes hansenianos atendidos no Instituto Lauro de Souza Lima (ILSL): um estudo retrospectivo de 4 anos consecutivos (1995 - 1998) / ?

A hanseniase e uma doenca cronica granulomatosa causada pelo Mycobacterium leprae. Caracteriza-se pela presenca de lesoes na pele e pelo comprometimento dos nervos perifericos, com perda parcial ou total da sensibilidade, que pode evoluir para processos deformativos e destrutivos. As infeccoes bacterianas secundarias sao consequencias graves da falta de sensibilidade, principalmente em membros inferiores, gerando lesoes graves e ate necrose. A anidrose provoca fissuras na pele que tambem podem infectar-se, levando a destruicao dos tecidos. Em pacientes hospitalizados esse quadro se agrava, pois estes ficam expostos a bacterias oportunistas com alto grau de resistencia aos antimicrobianos. O objetivo deste trabalho foi analisar retrospectivamente