Clinical, Cosmetic and Investigational Dentistry (Aug 2022)

Comparative Evaluation of Bulk-Fill Composite Resins: Knoop Microhardness, Diametral Tensile Strength and Degree of Conversion

  • Strini BS,
  • Marques JFL,
  • Pereira R,
  • Sobral-Souza DF,
  • Pecorari VGA,
  • Liporoni PCS,
  • Aguiar FHB

Journal volume & issue
Vol. Volume 14
pp. 225 – 233

Abstract

Read online

Bruna Scarcello Strini,1 Joyce Figueiredo de Lima Marques,1 Renata Pereira,1 Danielle Ferreira Sobral-Souza,2 Vanessa Gallego Arias Pecorari,3 Priscila Christiane Suzy Liporoni,4 Flávio Henrique Baggio Aguiar1 1Department of Restorative Dentistry, Piracicaba Dental School, University of Campinas, Piracicaba, SP, Brazil; 2Dental School, Federal University of Mato Grosso do Sul, Campo Grande, MS, Brazil; 3Department of Biostatistics, Piracicaba Dental School, University of Campinas, Piracicaba, SP, Brazil; 4Department of Restorative Dentistry, University of Taubate, Taubaté, SP, BrazilCorrespondence: Joyce Figueiredo de Lima Marques, Department of Restorative Dentistry, Piracicaba Dental School, University of Campinas, Av. Limeira, 901, Piracicaba, SP, 13414-903, Brazil, Tel +55 19 2106-5337 ; +55 84 99966-8539, Fax +55 19 3421-0144, Email [email protected]: Bulk-fill composite resins were developed to reduce time and facilitate the restorative procedure. However, considering their recent introduction on the market and the new formulations, their performance still requires evaluation. This study aimed to evaluate Knoop microhardness (KHN), diametral tensile strength (DTS) and degree of conversion (DC) of three Bulk-Fill composite resins and a conventional one.Materials and Methods: Sixty samples (n = 15; 8 mm ø x 4 mm height) were confectioned using a mold. Filtek Bulk-Fill (FBF), Tetric N-Ceram Bulk-Fill (TNC) and SonicFill 2 (SF2) were placed in 4 mm increments, and Filtek Z350 (FZ350) was placed in 2 mm increments. The KHN of top and bottom surfaces were tested using Knoop Hardness tester at 10 gf/10s. The DTS was tested under compressive load at 1.0 mm/min. The DC was measured by Fourier Transform Infrared (FTIR) spectroscopy. Differences in DTS and DC were analyzed by ANOVA and Tukey post hoc test. For KHN, Kruskal–Wallis and Wilcoxon tests were performed at α = 0.05.Results: Top surfaces of all composite resins had higher KHN than bottom surfaces. At top and bottom surfaces, FZ350 showed higher KHN than TNC and SF2. The highest DTS was obtained by FBF, followed by FZ350 and SF2. The highest DC was obtained by SF2, the lowest one was obtained by FBF.Conclusion: From Bulk-Fill composite resins, FBF presented the best KHN and DTS results. The SF2 showed the best DC. Further studies are required to ensure whether these differences can negatively influence the behavior of in vivo restorations.Keywords: composite resins, Bulk-Fill, FTIR, hardness, tensile strength

Keywords