Document Type
Article
Publication Date
10-2020
Publisher
Elsevier
Source Publication
Dental Materials
Source ISSN
1879-0097
Original Item ID
10.1016/j.dental.2020.07.004
Abstract
Objectives
To investigate the role of proteoglycans (PGs) on the physical properties of the dentin matrix and the bond strength of methacrylate resins with varying hydrophilicities.
Methods
Dentin were obtained from crowns of human molars. Enzymatic removal of PGs followed a standard protocol using 1 mg/mL trypsin (Try) for 24 h. Controls were incubated in ammonium bicarbonate buffer. Removal of PGs was assessed by visualization of glycosaminoglycan chains (GAGs) in dentin under transmission electron microscopy (TEM). The dentin matrix swelling ratio was estimated using fully demineralized dentin. Dentin wettability was assessed on wet, dry and re-wetted dentin surfaces through water contact angle measurements. Microtensile bond strength test (TBS) was performed with experimental adhesives containing 6% HEMA (H6) and 18% HEMA (H18) and a commercial dental adhesive. Data were statistically analyzed using ANOVA and post-hoc tests (α = 0.05).
Results
The enzymatic removal of PGs was confirmed by the absence and fragmentation of GAGs. There was statistically significant difference between the swelling ratio of Try-treated and control dentin (p < 0.001). Significantly lower contact angle was found for Try-treated on wet and dry dentin (p < 0.002). The contact angle on re-wet dentin was not recovered in Try-treated group (p = 0.9). Removal of PGs significantly improved the TBS of H6 (109% higher, p < 0.001) and H18 (29% higher, p = 0.002) when compared to control. The TBS of commercial adhesive was not affected by trypsin treatment (p = 0.9).
Significance
Changing the surface energy of dentin by PGs removal improved resin adhesion, likely due to more efficient water displacement, aiding to improved resin infiltration and polymerization.
Recommended Citation
Farina, Ana Paula; Cecchin, Doglas; Vidal, Cristina M. P.; Leme-Kraus, Ariene A.; and Bedran-Russo, Ana K., "Removal of Water Binding Proteins from Dentin Increases the Adhesion Strength of Low-Hydrophilicity Dental Resins" (2020). School of Dentistry Faculty Research and Publications. 385.
https://epublications.marquette.edu/dentistry_fac/385
Comments
Accepted version. Dental Materials, Vol. 36, No. 10 (October 2020): 302-308. DOI. © 2020 Elsevier. Used with permission.
Ana K. Bedran-Russo was affiliated with University of Illinois at Chicago at the time of publication.