Photodynamic therapy with acai (Euterpe oleracea) and blue light in oral cells: A spectroscopic and cytotoxicity analysis.

OBJECTIVE: To evaluate the potential of photodynamic therapy (PDT) with blue light-emitting diode (LED) 460 nm at 25, 50 and 100 J/cm2 using three concentrations of acai extracts (100, 40, and 10 mg/ml), in the proliferation and viability of head and neck tumor lines (SCC9). METHODS: Three groups of cells were analyzed for 3 days in an in vitro assay with MTT (3- (4,5-dimethylthiazol-2-yl) -2,5, -diphenyltetrazolium bromide) and crystal violet: cells in the absence of acai extract and PDT (control group); cells in the presence of acai extract and no light; and cells in the presence of acai extract and LED blue light (PDT groups). RESULTS: When using acai as a PS combined with blue LED (460 nm, 0.7466 cm2 , 1000 mW/cm2 ) and irradiation at 25, 50, and 100 J/cm2 , after 72 h, cell viability (p < 0.0001 vs. control, p = 0.0027 vs. 100 mg/ml açai group, p = 0.0039 vs. 40 mg/ml açai group, p = 0.0135 vs. 10 mg/ml açai group; One-Way ANOVA/Tukey) and proliferation (p < 0.05, One-Way ANOVA/Tukey) decreased. CONCLUSION: The acai in question is a potential photosensitizer (PS), with blue light absorbance and efficacy against head and neck tumor lines (SCC9).

The effect of antimicrobial photodynamic therapy on infected dentin in primary teeth: A randomized controlled clinical trial protocol.

BACKGROUND: Antimicrobial photodynamic therapy (aPDT) has been used for the treatment of dental caries. Papacarie is a gel composed of papain and chloramine employed for the partial removal of carious tissue, effective against bacteria, however, some studies report that this antibacterial action is not quite so evident. The aim of this study is to evaluate the clinical effect of aPDT on infected dentin in dental caries lesion in primary teeth. METHODS: Thirty-two primary molars with deep occlusal dental caries will be selected and divided in 2 groups: G1 - caries removal with a low-speed drill and G2 - application of aPDT with PapacarieMBlue. After treatment, all the teeth will be restored with glass ionomer cement and followed up clinically and radiographically, with evaluations at 3, 6, and 12 months. Dentin samples before and after treatment will be analyzed microbiologically. The data will be submitted to descriptive statistical analysis of the association between the categorical variables and both age and gender using the chi-square test and Fisher exact text. The Student t test and analysis of variance will be used for the comparison of mean signs and symptoms of reversible pulpitis. Pearson correlation coefficients will be calculated for the analysis of correlations among the continuous variables. DISCUSSION: Adding methylene blue dye to the formula of PapacarieMBlue might potentiate the antimicrobial action of aPDT and work more effectively on the infected dentin combined with a conservative, minimally invasive treatment. TRIAL REGISTRATION: NCT02734420 on 10 march 2016.

Effect of papain-based gel on type I collagen--spectroscopy applied for microstructural analysis.

Considering the improvement of biomaterials that facilitate atraumatic restorative techniques in dentistry, a papain-based gel can be used in the chemomechanical removal of decayed dental tissue. However, there is no information regarding the influence of this gel on the structure of sound collagen. The aim of the present study was to investigate the adsorption of a papain-based gel (Papacarie(TM)) to collagen and determine collagen integrity after treatment. A pilot study was first performed with 10 samples of type I collagen membrane obtained from bovine Achilles deep tendon to compare the influence of hydration (Milli-Q water) on infrared bands of collagen. In a further experiment, 10 samples of type I collagen membrane were used to evaluate the effects of Papacarie(TM) on the collagen microstructure. All analyses were performed using the attenuated total reflectance technique of Fourier transform infrared (ATR-FTIR). The results demonstrated that the application of Papacarie(TM) does not lead to the degradation of collagen and this product can be safely used in minimally invasive dentistry. As the integrity of sound collagen is preserved after the application of the papain-based gel, this product is indicated for the selective removal of infected dentin, leaving the affected dentin intact and capable of re-mineralization.