In vitro evaluation of physicochemical properties of soft lining resins after incorporation of chlorhexidine

Caroline Vieira Maluf; Camilla Alves Janott-Sarlo; Martinna de Mendonça Bertolini; Lívia Rodrigues Menezes; Eduardo José Veras Lourenço; Daniel de Moraes Telles

doi:10.1016/j.prosdent.2020.03.027

In vitro evaluation of physicochemical properties of soft lining resins after incorporation of chlorhexidine

J Prosthet Dent. 2020 Nov;124(5):615.e1-615.e7. doi: 10.1016/j.prosdent.2020.03.027. Epub 2020 Jun 13.

Authors

Caroline Vieira Maluf¹, Camilla Alves Janott-Sarlo², Martinna de Mendonça Bertolini³, Lívia Rodrigues Menezes⁴, Eduardo José Veras Lourenço⁵, Daniel de Moraes Telles⁶

Affiliations

¹ Postdoctoral student, Department of Prosthodontics, Rio de Janeiro State University, Rio de Janeiro, Brazil.
² Researcher, Department of Prosthodontics, Rio de Janeiro State University, Rio de Janeiro, Brazil.
³ Researcher, Department of Oral Health and Diagnostic Sciences, UConn Health Center, Farmington, Conn.
⁴ Adjunct Professor, Institute of Macromolecules Eloisa Mano, Rio de Janeiro Federal University, Rio de Janeiro, Brazil.
⁵ Associate Professor, Department of Prosthodontics, Rio de Janeiro State University, Rio de Janeiro, Brazil.
⁶ Full Professor, Department of Prosthodontics, Rio de Janeiro State University, Rio de Janeiro, Brazil. Electronic address: dmtelles@uerj.br.

PMID: 32540125
DOI: 10.1016/j.prosdent.2020.03.027

Abstract

Statement of problem: Incorporating chlorhexidine into soft lining materials has been suggested to reduce biofilm development on the material surface and treat denture stomatitis. However, evaluation of the physicochemical properties of this material is necessary.

Purpose: The purpose of this in vitro study was to evaluate the physicochemical properties of resin-based denture soft lining materials modified with chlorhexidine diacetate (CDA).

Material and methods: Two soft lining resins were tested, one based on polymethyl methacrylate (PMMA) and the other on polyethyl methacrylate (PEMA), into which 0.5%, 1.0%, or 2.0% of CDA was incorporated; the control group had no CDA. The specimens were stored for 2 hours, 48 hours, 7, 14, 21, and 28 days and then analyzed for polymer crystallinity, Shore A hardness, degree of monomer conversion, residual monomer leaching, and CDA release. Data were analyzed by using a 3-way ANOVA and the Tukey HSD test (α=.05).

Results: The polymer crystallinity of PEMA and PMMA did not change after CDA incorporation. Shore A hardness increased over time, but not for any CDA concentrations tested after 28 days (P>.05). Considering the degree of conversion, PMMA-based resin showed no statistically significant difference (P>.05). However, PEMA-based resin showed a significant decrease (P<.05), which was reflected in a significant increase in residual monomer leaching from PEMA-based resin with the incorporation of 0.5% and 1.0% CDA (P<.05), mainly in the first 48 hours. PMMA-based resin showed no change in monomer leaching (P>.05). For both resins, the CDA release kinetics were related to monomer leaching; for PEMA-based resin, the values were significantly higher in the first 48 hours (P<.05), and for PMMA-based resin, the values were more sustained up to the last day of analysis.

Conclusions: The incorporation of CDA did not affect the physicochemical properties of soft resins. The properties of PMMA were better than those of PEMA.

MeSH terms

Chlorhexidine*
Denture Bases
Hardness
Materials Testing
Methacrylates
Polymethyl Methacrylate*
Surface Properties

Substances

Methacrylates
Polymethyl Methacrylate
Chlorhexidine