Banca de DEFESA: TERESA DE LISIEUX GUEDES FERREIRA LÔBO

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : TERESA DE LISIEUX GUEDES FERREIRA LÔBO
DATE: 10/02/2021
TIME: 09:00
LOCAL: Vídeoconferência
TITLE:

“Synthesis and characterization of a dental adhesive with Silver nanoparticles biosynthesized with red propolis from Alagoas.”

KEY WORDS:

Dentin adhesives, antioxidants, nanoparticles, silver nitrate, propole.

PAGES: 133
BIG AREA: Ciências da Saúde
AREA: Odontologia
SUBÁREA: Materiais Odontológicos
SUMMARY:

Biogenic synthesis uses natural raw material to reduce macromolecules in nanoparticles and propolis is an alternative in reducing the toxicity of silver nanoparticles. Objective: The objective of this work was to produce and characterize a dental adhesive with silver nanoparticles biosynthesized with red propolis from Alagoas. Methodology: Antioxidant (DPPH method) and antimicrobial activities against Streptococcus mutans, Staphylococcus aureus, Staphylococcus epidermidis, Enterococcus faecalis, by the methods of Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (CBM) of the ethanolic extract of red propolis from Alagoas (EPV), of silver nanoparticles synthesized in a conventional way (NPAgC) and biosynthesized with EPV (NPAgB) and the mixture of NPAgC + EPV. Six patches with NPAgB 250 µg / mL were developed; NPAgC 250 µg / ml; EPV 250 µg / mL; EPV 300 µg / mL; NPAgC 250 µg / mL + EPV 250 and NPAgC 250 µg / mL + EPV 300. Pure adhesive (AE) and Single Bond 2 (3M / ESPE) were used as controls. AE was also tested with 24 µL of ethanol (solvent) to check the effect of the solvent. EPV and NPAgB were subjected to high performance liquid chromatography (HPLC) assays to determine and quantify propolis biomarkers that reduce silver in nanomaterials. The experimental adhesives were characterized by measurements of the degree of conversion (infrared spectroscopy (FTIR), release of nanoparticles in artificial saliva from the polymerized adhesive and antibacterial activity by the disk diffusion method (MDD). Technological research was carried out on the topic. GC data were analyzed using one-way ANOVA (α = 0.05). Results: The average content of flavonoids in the EPV was 1.56% and antioxidant activity (AA%) ranging from 3.15 to 10.53% on average. NPAgB and NPAgC were obtained in the form of a light, fine, spherical shape, blackish in color for NPAgB and silver in color for NPsAgC. Compared to NPAgC, NPAgB showed better results of bacteriostatic activity, except against Enterococcus faecalis, where a similar result was observed for both types of NPs. The bactericidal effect of NPAgB was better for S. mutans and S. epidermidis than NPAgC. NPAgB showed AA% better than NPAgC. The red propolis markers that reduce the silver molecule in nanomaterials were obtained. The degree of conversion of the adhesives varied between 76.19 and 87.57% (p> 0.05). The MDD assay showed better results for NPAgB with a diffusion radius of 3.7mm. The release test carried out in spectrometry and absorption in UV-Vis demonstrated that the adhesives do not release NPs.The microtensile test demonstrated that although the NPAgB (39.56 MPa), EPV 250 (45.85 MPa) and EPV 300 (39.77 Mpa) adhesives had significantly higher immediate bond strength than the control group (34.88 Mpa) there is no significant difference between the analyzed adhesives (p> 0.05). The predominant fracture mode test in all promotion groups was mixed fracture. Conclusion: The synthesis of a dental adhesive with silver nanoparticles biosynthesized with red propolis from Alagoas resulted in a material with antimicrobial activity and a stable matrix with the active principle immobilized within the material.

BANKING MEMBERS:
Interna - 1527220 - CAMILA BRAGA DORNELAS
Interna - 1885138 - ISABEL CRISTINA CELERINO DE MORAES PORTO
Externo à Instituição - MARCOS ANTÔNIO JAPIASSU RESENDE MONTES - UPE
Interno - 1488396 - TICIANO GOMES DO NASCIMENTO