Effects of hybrid inorganic-organic nanofibers on the properties of enamel resin infiltrants - An in vitro study

Alyssa Teixeira Obeid; Luisa Helena Antunes Garcia; Tatiana Rita de Lima Nascimento; Lúcio Roberto Cançado Castellano; Juliana Fraga Soares Bombonatti; Heitor Marques Honório; Rafael Francisco Lia Mondelli; Salvatore Sauro; Marilia Mattar de Amoêdo Campos Velo

doi:10.1016/j.jmbbm.2021.105067

Effects of hybrid inorganic-organic nanofibers on the properties of enamel resin infiltrants - An in vitro study

J Mech Behav Biomed Mater. 2022 Feb:126:105067. doi: 10.1016/j.jmbbm.2021.105067. Epub 2022 Jan 4.

Authors

Alyssa Teixeira Obeid¹, Luisa Helena Antunes Garcia², Tatiana Rita de Lima Nascimento³, Lúcio Roberto Cançado Castellano⁴, Juliana Fraga Soares Bombonatti⁵, Heitor Marques Honório⁶, Rafael Francisco Lia Mondelli⁷, Salvatore Sauro⁸, Marilia Mattar de Amoêdo Campos Velo⁹

Affiliations

¹ Department of Operative Dentistry, Endodontics and Dental Materials, Bauru School of Dentistry, University of São Paulo, Alameda Octávio Pinheiro Brisolla, 9-75, Bauru, SP, 17012-901, Brazil. Electronic address: alyssa.obeid@usp.br.
² Department of Operative Dentistry, Endodontics and Dental Materials, Bauru School of Dentistry, University of São Paulo, Alameda Octávio Pinheiro Brisolla, 9-75, Bauru, SP, 17012-901, Brazil. Electronic address: luisahelenaag@usp.br.
³ Technical School of Health, Federal University of Paraíba, Cidade Universitária, João Pessoa, PB, 58059-900, Brazil. Electronic address: tatirln@hotmail.com.
⁴ Technical School of Health, Federal University of Paraíba, Cidade Universitária, João Pessoa, PB, 58059-900, Brazil. Electronic address: luciocastellano@gmail.com.
⁵ Department of Operative Dentistry, Endodontics and Dental Materials, Bauru School of Dentistry, University of São Paulo, Alameda Octávio Pinheiro Brisolla, 9-75, Bauru, SP, 17012-901, Brazil. Electronic address: julianafraga@usp.br.
⁶ Department of Pediatric Dentistry, Orthodontics and Public Health, Bauru School of Dentistry, University of São Paulo, Alameda Octávio Pinheiro Brisolla, 9-75, Bauru, SP, 17012-901, Brazil. Electronic address: heitorhonorio@usp.br.
⁷ Department of Operative Dentistry, Endodontics and Dental Materials, Bauru School of Dentistry, University of São Paulo, Alameda Octávio Pinheiro Brisolla, 9-75, Bauru, SP, 17012-901, Brazil. Electronic address: rafamond@fob.usp.br.
⁸ Dental Biomaterials and Minimally Invasive Dentistry, Department of Dentistry, Cardenal Herrera-CEU University, CEU Universities, C/Santiago Ramón y Cajal, S/n., Alfara Del Patriarca, 46115, Valencia, Spain; Department of Therapeutic Dentistry, I. M. Sechenov First Moscow State Medical University, 119146, Moscow, Russia. Electronic address: salvatore.sauro@uchceu.es.
⁹ Department of Operative Dentistry, Endodontics and Dental Materials, Bauru School of Dentistry, University of São Paulo, Alameda Octávio Pinheiro Brisolla, 9-75, Bauru, SP, 17012-901, Brazil. Electronic address: mariliavelo@usp.br.

PMID: 35026564
DOI: 10.1016/j.jmbbm.2021.105067

Abstract

This in vitro study aimed to evaluate the overall mechanical properties of resin infiltrants doped with bioactive nanofibers and their ability in inhibiting enamel demineralization or achieving remineralization of the adjacent enamel to white spots. A commercial resin infiltrant (ICON, DMG) was doped with hybrid inorganic-organic nanofibers and analyzed for degree of conversion (DC, n = 3) and surface hardness (SH, n = 6). Subsequently, enamel specimens (6 × 4 × 2 mm³) were prepared and submitted to a demineralizing/remineralizing process to produce a subsurface caries-like lesion. The specimens were treated with one of the following materials: ICON infiltrant, DMG (control); ICON + nanofibers of poly-lactic acid (PLA)-filled with silica (PLA-SiO₂); ICON + nanofibers of (PLA)-filled with calcium incorporated into a silica network (SiO₂-CaP). Then, the specimens were subjected to a pH-cycling demineralizing/remineralizing model for 7 days at 37 °C. The %ΔSH change (after treatment), %SH loss and %SH recovery (after pH-cycling regimen) were calculated after SH evaluation (n = 9/group). The Ca/P weight ratio before and after pH-cycling regimen was evaluated through SEM/EDX. The results of DC were analyzed through the T-test (p < 0.05). ANOVA followed by Tukey's test (p < 0.05) was performed for hardness and EDX. A significant SH increase was observed in the ICON/SiO₂CaP group (p < 0.05). The ICON/PLA-SiO₂ presented higher DC values than the control group (p = 0.043). All groups presented significant difference in %ΔSH (p < 0.05), although the specimens treated with ICON/SiO₂CaP presented greater values. Regarding the %SHL and %SHR, the ICON/SiO₂CaP and ICON/PLA-SiO₂ were significantly different compared to the control group (p < 0.001). However, no difference was observed between the ICON/SiO₂CaP and ICON/PLA-SiO_2. The Ca/P ratio showed that the ICON/SiO₂CaP and ICON/PLA-SiO₂ after the pH-cycling regimen differed from sound enamel and modified infiltrants before pH-cycling. In conclusion, tailored hybrid nanofibers may be incorporated into enamel resin infiltrants without compromise the mechanical properties of such experimental materials. These latter can inhibit the demineralization of enamel and increase its hardness during pH-clycling challange.

Keywords: Caries; Enamel; Mechanical properties; Nanofibers; Resin infiltrant.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Dental Caries*
Hardness
Humans
Nanofibers*
Silicon Dioxide
Surface Properties

Substances

Silicon Dioxide