Santé bucco-dentaire et gestion dentaire

Abstrait

Influence of Monomers and Solvents on the Contact Angle, Penetrability and Knoop Hardness of Experimental Resin Infiltrants into Caries-Like Lesions

Tatiany Gabrielle Freire Araújo Guimarães, Victor Pinheiro Feitosa, Tainah Oliveira Rifane, Italo Hudson Tavares Maia, Ravana Angelini Sfalcin, Bruno Martini Guimarães, Americo Bortolazzo Correr

Objective: To evaluate the influence of monomers Urethane Dimethacrylate (UDMA), Ethoxylated Bisphenol A Glycidyl Dimethacrylate (BisEMA), and solvents Tetrahydrofuran (THF) and Dimethyl Sulfoxide (DMSO) on the contact angle, penetrability and Knoop microhardness of resin infiltrants into caries-like lesions.

Methods: Eleven groups were evaluated: 1) Icon; 2) 75% TEGDMA (T)+25%UDMA (U); 3) T+U+0.5%DMSO; 4) T+U+5%DMSO; 5) T+U+0.5%THF; 6) T+U+5%THF 7) 75% T+25%BisEMA(B); 8) T+B+0.5%DMSO; 9) T+B+5%DMSO; 10) T+B+0.5%THF; 11) T+B+5%THF. The contact angle measurement was performed in a viscosimeter (n=5). The resin infiltrants penetrability (n=5) by Confocal Laser Scanning Microscopy by qualitative analysis and Knoop microhardness (n=10) was evaluated in caries-like lesions produced on the enamel of bovine teeth. Contact angle data were submitted to one-way ANOVA and Tukey’s test. Knoop hardness was evaluated by two-way ANOVA and Tukey’s test. It was used 5% significance level.

Results: The icon showed a contact angle significantly lower (11.4(2.4)) than the other groups. T+U+5%DMSO (16.7(3.3)) showed significantly lower contact angle with statistical difference (p<0.001) when compared with T+U (29. 8(6.3)); T+U +0.5%DMSO (29.5(5.5)); T+U+5%THF (31.8(3.7)); T+B+0.5%DMSO (32.3(5.7)); and T+B+0.5%THF (29.8(3.6)) (p=0.0751). Confocal Laser Scanning Microscopy showed good penetration into the demineralized area of infiltrants with TEGDMA+UDMA blend base and Icon. Caries-like lesions infiltrated by Icon showed Knoop hardness significantly except for the T+U+0.5%DMSO and T+U+5%THF groups. Thus, the Knoop hardness significantly increased in deeper sites.

Conclusion: The solvent with a lower concentration (0.5%) associated with the BisEMA monomer did not provide greater penetration of the experimental infiltrants. Higher solvent concentrations are not recommended.