Comparison of results from two different leakage models to evaluate the apical sealing of endodontic materials

Introduction: The methods used to evaluate the apical sealing of root canal filling materials have some limitations and great variability of results can be observed. Aim: The aim of this study was to compare, in an ex vivo apexification model, the results from bacterial and glucose leakage tests, which were applied in mineral trioxide aggregate (MTA) apical plugs. Materials and Methods: Sixty root segments (12mm) were randomly divided into 2 experimental groups (n=30): G1) MTA; G2) MTA + phosphate-buffered saline intracanal. Half of the specimens in each group were submitted to bacterial leakage test with E. faecalis for 70 days. The other half was submitted to the glucose leakage test under pressure (103KPa) for 60 min. The results from the two tests were compared based on the number of specimens presenting leakage. Data were analyzed by Fisher's test (p < 0.05). Results: There was no significant difference between tests for both groups analyzed (p > 0.05).Conclusion: The results of the present ex vivo study demonstrated that there was no difference between glucose and bacteria leakage evaluation methods, within the parameters of the present study and regardless

Effectiveness of nanoparticles solutions and conventional endodontic irrigants against Enterococcus faecalis biofilm

To overcome the challenge imposed by the presence of biofilm and reach significant bacterial reduction of the root canals, many irrigants have been indicated during endodontic treatment, among them nanoparticles solutions. Aims: This study aims to evaluate the effectiveness of experimental solutions containing silver and zinc oxide nanoparticles (ZnO Np) and conventional endodontic irrigants against Enterococcus faecalis biofilm, in root canals. Methods: Seventy-six extracted human teeth were biomechanically prepared and sterilized. The root canal surface was exposed to E. faecalis suspension to form a 7-day-old biofilm. Four teeth were analyzed by scanning electron microscopy (SEM) to confirm the presence of biofilm. The remaining teeth were randomly divided into 6 groups (n = 12) and treated with passive ultrasonic irrigation and different solutions: G1 – 0.85% saline (control); G2 – 2% chlorhexidine gluconate (CHX); G3 – 5% sodium hypochlorite (NaOCl); G4 – 1% NaOCl; G5 – 1% silver nanoparticles (Ag Np) solution; and G6 – 26% ZnO Np solution. The susceptibility of E. faecalis biofilms to disinfecting solutions (n = 10) was determined by quantification of colony-forming units. SEM analysis was also carried out to examine the biofilm structure after treatments (n = 2). Data were analyzed by Kruskal–Wallis and Dunn post hoc tests (P < 0.05). Results: All tested solutions showed superior effectiveness compared to 0.85% saline (P < 0.05). Overall, 2% CHX presented the most effective action against E. faecalis biofilm, followed by 5% NaOCl, 1% Ag Np, 26% ZnO Np, and 1% NaOCl. Conclusions: 1% Ag Np and 26% ZnO Np were effective against E. faecalis biofilm similarly to conventional endodontic irrigants.

Effect of γ-lactones and γ-lactams compounds on Streptococcus mutans biofilms

Abstract Considering oral diseases, antibiofilm compounds can decrease the accumulation of pathogenic species such as Streptococcus mutans at micro-areas of teeth, dental restorations or implant-supported prostheses. Objective To assess the effect of thirteen different novel lactam-based compounds on the inhibition of S. mutans biofilm formation. Material and methods We synthesized compounds based on γ-lactones analogues from rubrolides by a mucochloric acid process and converted them into their corresponding γ-hydroxy-γ-lactams by a reaction with isobutylamine and propylamine. Compounds concentrations ranging from 0.17 up to 87.5 μg mL-1 were tested against S. mutans. We diluted the exponential cultures in TSB and incubated them (37°C) in the presence of different γ-lactones or γ-lactams dilutions. Afterwards, we measured the planktonic growth by optical density at 630 nm and therefore assessed the biofilm density by the crystal violet staining method. Results Twelve compounds were active against biofilm formation, showing no effect on bacterial viability. Only one compound was inactive against both planktonic and biofilm growth. The highest biofilm inhibition (inhibition rate above 60%) was obtained for two compounds while three other compounds revealed an inhibition rate above 40%. Conclusions Twelve of the thirteen compounds revealed effective inhibition of S. mutans biofilm formation, with eight of them showing a specific antibiofilm effect.

Pesquisa a serviço da sociedade: área de concentração de Implantodontia do PPGO/UFSC / Scientific research for social benefits: oral Implantology at the PPGO/UFSC

Este manuscrito descreve as atividades desenvolvidas na PPGO/UFSC, concentradas em três linhas de pesquisa: 1) neoformação óssea peri-implantar; 2) engenharia tecidual; e 3) microbiologia aplicada à Implantodontia. Na linha um, diversos métodos analíticos quantitativos e qualitativos (SEM, AFM, FTIR, OCP, EIS, FEG-SEM) têm sido usados para investigação de diferentes intensidades de corrente elétrica na superfície do Ti-cp e Ti-6Al-4V, quando imersos em meios fisiológicos simulados, na adsorção de proteínas, proliferação celular com fibroblastos, queratinócitos e osteoblastos. Na linha dois, o desenvolvimento in vitro de um arcabouço poroso de PLGA e cerâmica bifásica, incorporado com sinvastatina, sera testado in vivo na resposta de fibroblastos gengivais provenientes de cultura primaria, em meio de cultura com plasma rico em plaquetas (PRP), depositado sobre matriz dérmica acelular e matriz de celulose bacteriana (BC). A linha três concentra a atuação com dois centros internacionais (Belgica e EUA) para a incorporação de compostos antibiofilme em polímeros biocompatíveis, e verificação da eficiência de um método de liberação prolongada de antibióticos incorporados em superfícies nanoestruturadas. Estes projetos devem resultar em melhoria de saúde aos pacientes e no desenvolvimento econômico e social da comunidade.

This paper describes the activities developed at PPGO/UFSC divided into three research lines: 1) peri-implant bone neoformation; 2) tissue engineering, and 3) microbiology applied to implant dentistry. On the first line, several quantitative and qualitative (SEM, AFM, FTIR, OCP, EIS, FEG-SEM) analytical methods have been used to investigate the different electric current intensities on Ti c.p. and Ti6Al4V implant surfaces when immersed into simulated physiological media, protein adsorption, cell proliferation with fibroblasts, keratinocytes, and osteoblasts. On the second line, the in vitro development of a 3D PLGA and biphasic ceramic, simvastatin-incorporated scaffold will be tested in vivo for gingival fibroblast response from primary culture in platelet-rich plasma (PRP) enriched vehicle over an acellular dermal (Sure- Derm) and bacterial cellulose matrix (BC). For line three, two international research centers (Belgium and USA) joined common efforts to incorporate polymer anti-biofi lm compounds and to verify the efficiency of a prolonged release method for antibiotics attached to nanostructured surfaces. All those projects must result in better health conditions and social and economic development of our community.