Banca de QUALIFICAÇÃO: RAFAELA ALCINDO SILVA

Uma banca de QUALIFICAÇÃO de MESTRADO foi cadastrada pelo programa.
STUDENT : RAFAELA ALCINDO SILVA
DATE: 26/04/2022
TIME: 14:00
LOCAL: Online
TITLE:

EVALUATION OF THE PHYSICAL, CHEMICAL AND OSTEOGENICS OF PORTLAND CEMENT ASSOCIATED WITH NIOBIUM(

KEY WORDS:

Portland Cement; Mineral trioxide aggregate; Chemical composition; Niobium.

PAGES: 59
BIG AREA: Ciências da Saúde
AREA: Odontologia
SUBÁREA: Endodontia
SUMMARY:

Mineral Trioxide Aggregate (MTA) is a material used for reparative purposes in Endodontics, characterized by presenting biocompatibility, radiopacity, low solubility and antimicrobial action.Composed of 75% Portland Cement (CP), 20% Bismuth Oxide and 5% Gypsum (Calcium Sulfate). However, Bismuth oxide compromises essential properties of MTA. This work aimed to develop, characterize and evaluate the osteogenic activity of PC formulations with different proportions of Niobium oxide, replacing Bismuth. Three groups were used, one control and two experimental: GC (MTA Angelus®), F6 (75% CP, 20% Niobium Oxide and 5% Gypsum) and F7 (75% CP, 10% Bismuth Oxide, 10% of Niobium and 5% of Gypsum). The formulations were submitted to X-ray Diffraction (XRD),, Scanning Electron Microscopy (SEM), Fourier Transform Infrared Spectroscopy (FTIR) and X-ray Fluorescence Spectrometry (FRX). The pH, setting time and radiopacity tests followed the standards of ISO 6876:2012.The Calcium Ion Release followed the standards of the Standard Methods for the Examination of Water and Wastewater. In determining the compressive strength, theANSI/ADA No. 57 standard was used. To evaluate the cytotoxicity and bioactivity, theAlamar Blue and Alkaline Phosphatase assay was used. The data obtained were statistically evaluated by the test of variance (ANOVA) with Bonferroni correction (p<0.05%). The pH test results showed the following values: Niobio 10% Immediate:12.205 ±0.304; 24h: 12.770 ± 0.226; 48h: 12.910 ± 0.169. Niobium 20%: immediate:12.080 ± 0.282; 24 h: 12.350 ± 0.593; 48 h: 12.580 ± 0.73. For setting time in seconds,the initial setting of MTA was 397,500 +10,606, 10% niobium 294,333 + 90,897, and for 20% niobium 279,000 + 15,874. The final setting time for MTA was 815,000 +49,497, Niobium 10% presented a final setting time of 560 ±38,587, being significantly lower when compared to MTA (p<0.001) and the formulation Niobium 20% which was 715.666 ± 30.664 (p<0.01). The radiopacity values for 10% niobium were 3.888 ±0.340 mmAl and for 20% niobium 3.713 ± 0.712 mmAl. The analysis of calcium ion release in mg/L showed that there was a statistical difference in calcium release in the time period of 24h and 36h between the 10% Niobium (p<0.001) and 20% Niobium (p<0.001) groups when compared to immediate time. The compressive strength for 10% niobium was 694.150 + 78.951 MPa, while for 20% niobium 699.295 + 47.672 MPa. Cell viability showed no difference between MTA and experimental groups (p<0.05). The results of the mean and standard deviation of the osteogenesis capacity of the formulations from the alkaline phosphatase activity (ALF) test stand out with the highest means of alkaline phosphatase in the MTA groups (1.9 + 1.227 IU/L per gram of protein) and 20% Niobium (1.784 + 1.342 IU/L per gram of protein) (p>0.05). Our findings point to relevant properties for Niobio formulations presenting alkaline pH, calcium ion release, radiopacity, compressive strength and alkaline phosphatase activity. We suggest additional in vivo studies to prove biocompatibility.

BANKING MEMBERS:
Presidente - 2374605 - AURIGENA ANTUNES DE ARAUJO
Interno - 1879551 - FABIO ROBERTO DAMETTO
Externo ao Programa - 1753094 - ALCIDES DE OLIVEIRA WANDERLEY NETO