Physicochemical Properties and Structural Changes of Polyvinyl Butyral/Nanosilica Oxide Modified BioRoot Sealer: An In Vitro Study
Wiaam M. O. AL-Ashou, Raghad A. Al-Askary, Mohanad Y. Saleh
Abstract
Objective:
This study aimed to evaluate the influence of incorporating polyvinyl butyral (PVB) and nanosilica (SiO 2 ) on solubility, pH, and chemical structure changes of BioRoot™ root canal sealer (RCS) sealer.
Methods:
The BioRoot™ RCS powder was modified by incorporating 4% PVB/2% SiO 2 . The Fourier transform infrared spectroscopy (FTIR) analysis was performed to identify the possible structural changes that may have occurred in the modified sealer after incorporating 4% PVB and 2% SiO 2 into the sealer powder. For the solubility of the original and modified BioRoot™ RCS, it was performed in accordance with American National Standards Institute/American Dental Association No.57/2012 and International Organization for Standardization 6876:2012 at different storage periods (1, 3, 7, 14, 21, and 28 days). For pH analysis, measurements were performed at 3 and 24 h and on days 3, 7, 14, 21, and 28 after sample immersion in distilled water, using a digital pH meter.
Results:
FTIR analysis revealed specific structural alterations; the absorption band at 3564.15 cm −1 (OH group of water) shifted, and the band at 995.08 cm −1 (Si–O–Si) in the original BioRoot™ RCS was no longer noticeable in the modified sealer. The peaks of CH 2 and CH 3 at 1466.98 and 1446.67 cm −1 , respectively, became deeper and larger in the modified BioRoot™ RCS, confirming the successful integration of PVB/SiO 2 into the sealer matrix, which may play a role in reducing the solubility percentage. Two-way analysis of variance revealed that solubility and pH were significantly influenced by sealer type, time, and their interaction. The modified sealer exhibited significantly lower solubility than the original one at all tested time points, while both sealers maintained alkalinity, with pH dropping over time.
Conclusion:
The incorporation of 4%PVB/2%SiO 2 to BioRoot™ RCS sealer provides favorable physicochemical changes. These modifications significantly increase the hydrolytic stability of the material by reducing solubility while preserving its alkalinity, demonstrating the possibility of better clinical outcomes.