Effect of iodonium salt and chitosan on the physical and antibacterial properties of experimental infiltrants

Abstract

Resinous infiltrants are indicated in the treatment of incipient carious lesions, and further development of these materials may contribute to greater control of these lesions. The aim of this study was to analyze the physical and antibacterial properties of experimental infiltrants containing iodonium salt and chitosan. Nine experimental infiltrants were formulated by varying the concentration of the diphenyliodonium salt (DPI) at 0, 0.5 and 1 mol%; and chitosan at 0, 0.12 and 0.25 g%. The infiltrants contained the monomeric base of triethylene glycol dimethacrylate and bisphenol-A dimethacrylate ethoxylate in a 75 and 25% proportion by weight, respectively; 0.5 mol% camphorquinone and 1 mol% ethyl 4-dimethylaminobenzoate. The degree of conversion was evaluated using Fourier transformer infrared spectroscopy, and the flexural strength and elastic modulus using the three-point bending test. Sorption and solubility in water, and antibacterial analysis (minimum inhibitory concentration and minimum bactericidal concentration) were also analyzed. Data was analyzed statistically by two-way ANOVA and Tukey's test (p<0.05), with the exception of the antibacterial test, which was evaluated by visual inspection. In general, the infiltrant group containing 0.5% DPI and 0.12% chitosan showed high values of degree of conversion, higher values of elastic modulus and flexural strength, and lower sorption values in relation to the other groups. Antibacterial activity was observed in all the groups with DPI, regardless of the concentration of chitosan. The addition of DPI and chitosan to experimental infiltrants represents a valid option for producing infiltrants with desirable physical and antibacterial characteristics.

Avaliação de sorção/solubilidade, resistência à flexão, módulo de elasticidade e atividade antimicrobiana de infiltrantes experimentais / Evaluation of sorption/solubility, flexural strength, modulus of elasticity and antimicrobial activity of experimental infiltrants

“…Em relação a atividade antimicrobiana (tabela 5), o grupo 1 (DFI 0%; Quitosana 0%) e grupo 4 (Icon®) não apresentaram atividade antimicrobiana, tendo apresentado crescimento microbiano desde a menor concentração testada. Já o grupo 2 e grupo 3 apresentaram atividade antimicrobiana para S. mutans, sendo bactericidas, uma vez que de acordo com Levison e Levison (2009), uma substância é considerada bactericida quando o valor do CIM coincide com o valor de CBM, ou quando quociente de CIM por CBM é de no máximo 4 vezes, o que está de acordo com estudos prévios que indicaram bons resultados na adição de quitosana aos materiais dentários (Elsaka, 2012;Flor-Ribeiro, 2019), e a ação bactericida e bacteriostática da mesma (Costa et al, 2012;Íkinci et al, 2002), além da ação inibidora de largo espectro do DFI contra bactérias (Goldstein et al, 2004). Concluindo que a mistura do sal de DFI e quitosana foi benéfico para a atividade antimicrobiana do infiltrante.…”

“…Com base em estudos prévios (Araújo et al, 2013;Flor-Ribeiro, 2019) Icon ® Composição básica dos infiltrantes experimentais: BisEma (25%), TEGDMA (75%), HEMA (10%), CQ (0,5%), EDAB (1%).…”

“…Os infiltrantes agem em profundidade nas lesões de cárie incipiente, preservando o tecido dental, e demonstraram apresentar altos coeficientes de penetração de lesão cariosa (Paris et al, 2006). Para melhorias desses infiltrantes, o sal de difeniliodônio (DFI) (Gonçalves et al, 2013;Mathias et al, 2018) e a quitosana (Elsaka, 2012;Flor-Ribeiro et al, 2019) têm sido estudados por promover características benéficas aos materiais dentários. A quitosana como sendo um agente microbiano, quando adicionado aos materiais restauradores demonstra melhoria dos mesmos com relação às infiltrações bacterianas, o que pode aumentar seu desempenho clinico e diminuir o crescimento de biofilme (Inagaki, 2016).…”

Minimally Invasive Therapies for the Management of Dental Caries—A Literature Review

“…TEGDMA is hydrophilic and susceptible to water sorption and solubilization by saliva, leading to hydrolytic degradation in the oral environment, which diminishes their mechanical properties and clinical performance over time [ 172 ]. Since the behavior of the polymers is influenced by the chemical characteristics of the monomers, several attempts have been made to improve the mechanical and antibacterial properties of RIs by utilizing different monomer blends [ 123 , 184 , 185 , 186 , 187 ].…”

“…Along with releasing systems, contact-killing approaches have also been explored. Marchi et al sought to enhance the mechanical and antibacterial effect of TEGDMA/BisEMA based RI (HEMA diluent) with the addition of iodonium salt and chitosan [ 186 ] ( Figure 7 ). Onium salts were added to improve the mechanical properties of the material since these water-soluble salts have been shown to promote the polymerization of hydrophilic monomers owing to their ionic nature, resulting in a higher conversion of C=C bonds.…”