Hydroxylherderite as a Novel Filler for a Dental Adhesive
Bruna Genari *
Post-graduation Program in Dentistry, University of Brasilia - UnB, Brasília, Brazil and Department of Restorative Dentistry, School of Dentistry, Federal University of Minas Gerais - UFMG, Belo Horizonte, Brazil.
Scheila Bergel
School of Dentistry, UDF Universitary Center, Brasília, Brazil.
Amanda Nayara de Sousa Fonseca
School of Dentistry, UDF Universitary Center, Brasília, Brazil.
Melissa Camassola
Post-graduation Program in Dentistry, University of Brasilia - UnB, Brasília, Brazil and School of Dentistry, UDF Universitary Center, Brasília, Brazil.
Pedro Broglio
Oral Biochemistry and Microbiology Laboratory, School of Dentistry, Lutheran University of Brazil - ULBRA, Canoas, Brasil.
Ricardo Scholz
Department of Geology, Federal University of Ouro Preto - UFOP, Ouro Preto, Brazil.
Felipe Weidenbach Degrazia
Department of Restorative Dentistry, School of Dentistry, Federal University of Minas Gerais - UFMG, Belo Horizonte, Brazil.
*Author to whom correspondence should be addressed.
Abstract
Aims: The aim of this study was to incorporate Hydroxylherderite (HEr) into an adhesive and evaluate the resulting material’s properties including degree of conversion, microhardness, mineral deposition, and cytotoxicity.
Study Design: In vitro study.
Methodology: Hydroxylherderite was incorporated into the adhesive at concentrations of 2% and 5% by weight. The degree of conversion (DC, n = 3) was measured using an ATR-FTIR spectrometer. After immersion in absolute ethanol for two hours, the softening of the adhesive was assessed using a microhardness tester with a Knoop indenter. After 7 and 28 days of immersion in Simulated Body Fluid (SBF), mineral deposition in the adhesive was evaluated using a Raman microscope. Cell viability in contact with the adhesive was assessed according to ISO 10993-5. Data were analyzed using paired t-tests, ANOVA, and Tukey's post hoc tests with a significance level set at 0.05.
Results: The incorporation of HEr into the adhesive did not affect the degree of conversion compared to the control. DC ranged from 59.21 ± 11.11% to 63.49 ± 5.30%. The 5 wt% group showed a significant increase in initial microhardness (p < 0.05). Higher mineral deposition was observed with increased immersion time HEr concentration. All HEr concentrations maintained cell viability above 80% after 48 and 72 hours of contact.
Conclusion: HEr was successfully incorporated into the adhesive resin, promoting mineral deposition without cytotoxic effects and without compromising the physicochemical properties of adhesive.
Keywords: Adhesives, biomimetics, biotechnology, operative dentistry