Prof. Dr. Alessandra Nara de Souza Rastelli

• Department of Restorative Dentistry, School of Dentistry, Araraquara, Sao Paulo State University – UNESP, Araraquara, Sao Paulo, Brazil
• Doctor in Dental Science (DDS), graduated at the State University of Ponta Grossa-UEPG, School of Dentistry, Parana, Brazil (1996);
• Master’s (2002) and Ph.D. Degree (2004) in Restorative Dentistry at the Sao Paulo State University – UNESP, School of Dentistry, Araraquara, SP, Brazil;
• Associate Professor at School of Dentistry, Araraquara, Department of Restorative Dentistry of the Sao Paulo State University – UNESP, Brazil;
• Visiting Scientist at different Universities around the world, such as: University of Erlangen, Erlangen, Germany; Academic Centre for Dentistry Amsterdam – ACTA, Amsterdam, Netherlands; University of Birmingham, Dental School, Birmingham, UK and Wellman Center for Photomedicine, Massachusetts General Hospital, Harvard Medical School, University of Harvard, Boston, MA, USA;
• Head of the Biophotonics and Bionanomaterials Laboratory at School of Dentistry, Araraquara, Department of Restorative Dentistry of the Sao Paulo State University – UNESP, Brazil and she already published more than 100 papers based on the Biophotonics field.

Title: Violet LED Associated to Bleaching Agents and the Effect over Dental Enamel (Oral Presentation)

A violet LED device was introduced as a promising alternative to perform dental bleaching, associated or not with bleaching agents under different concentrations. This study evaluated the effect of different dental bleaching protocols by means of Knoop microhardness, mineral content, color changes and surface morphology. Bovine specimens (n=104, 4x4x2mm and n=80, 8x8x2mm) were obtained and after staining in coffee solution one half did not receive the bleaching procedure (control) and the another one received (treated). Different protocols were tested: G1: HP Maxx; G2: HP Maxx + Twin Flex Evolution; G3: HP Maxx + Bright Max Whitening; G4: 10% hydrogen peroxide; G5: 10% hydrogen peroxide + Bright Max Whitening; G6: 22% carbamide peroxide; G7: 22% carbamide peroxide + Bright Max Whitening and G8: Bright Max Whitening. The possible changes on the surface (S) and subsurface (SB) by Knoop microhardness, Raman spectroscopy and SEM were evaluated as well as color changes (S). Statistical analysis was performed by ANOVA and Tukey test at significance level of 5%. A significant effect of the bleaching protocols was observed for the microhardness, mineral content, color changes (p<0.05), and morphology. The absence of the gel can lead to minor changes on the enamel surface after dental bleaching.

Antimicrobial Photodynamic Therapy over Cariogenic Biofilms by the Use of ETNBS and BPD (Poster Session)

Authors: ¹*Alessandra Nara de Souza Rastelli, ²Leon G. Leanse, ²Tianhong Dai, ²Tayyaba Hasan

¹Sao Paulo State University – UNESP, School of Dentistry, Araraquara, SP, Brazil
²Wellman Center for Photomedicine, Massachusetts General Hospital, Harvard Medical School, Boston, USA

The susceptibility of multispecies cariogenic biofilm (S. mutans, S. sobrinus and A. naeslundi) to antimicrobial photodynamic therapy (aPDT) using ETNBS and BPD (PSs) at 5, 10, 20, 40 and 80 μM irradiated by a red laser at 635 and 690 nm under 10, 30 and 60 J/cm² and 5 min of pre- irradiation time was evaluated. The mechanisms of aPDT were also evaluated. Biofilms were cultured in BHI+1% sucrose (S. mutans and S. sobrinus) and Actinomyces (A. naeslundi) broth for 3 days in a 96 well-plate. Serial dilutions were seeded onto BHI and Actinomyces agar to determine viability  by CFU counting. The metabolism of the biofilm by XTT and confocal laser scanning microscopy (CLSM) was performed using BacLight^®LIVE/DEAD and Dextran Alexa Fluor^TM 647. Different groups were evaluated: L-D- (negative control), L-D+ (drug), L+D- (light), L+D+ (PDI) and chlorexidine at 0.12% (positive control). Two-way ANOVA and Tukey’s test (p<0.05) were performed. Qualitative analyzes were obtained as to the distribution of non-viable viable/cells after treatments. Statistically significant difference was observed for aPDT and chlorhexidine groups compared to negative and light controls (p<0.05). Antimicrobial photodynamic therapy using ETNBS and BPD can be an adjunct and effective method to control cariogenic biofilm.