Anti-Proteolytic Activity of Universal Adhesives on Artificially Eroded Dentin

Objectives: Universal adhesive systems (UAs) are versatile in promoting adhesion to dental substrates through acid-functional monomers. Alongside 10-MDP (10-methacryloyloxydecyl dihydrogen phosphate), combinations of carboxylic acid- and phosphoric acid-based monomers have been introduced to interact not only with mineral components but also with collagen. Among clinical challenges, Erosive Tooth Wear (ETW) induces mineral loss and collagen exposure, potentially increasing dentin susceptibility to enzymatic degradation and compromising adhesive procedures. This study aimed to evaluate the anti-proteolytic activity of UAs with distinct compositions on sound and artificially eroded dentin.
Methods: Two factors were analyzed: (1) adhesive systems: Adper Single Bond Universal (SU; 10-MDP-based), BeautiBond Xtreme (BX; carboxylic/phosphoric monomer-based and HEMA-free) and no treatment (NT; control); and (2) dentin condition: sound (S) and artificially eroded (E; 0.1% citric acid, 4x/ day for 5 days). Thirty bovine teeth were sectioned to obtain root dentin specimens (4 mm × 4 mm), with half undergoing erosive cycling. Specimens were treated with UAs, restored with resin composite, and assessed for enzymatic activity using in situ zymography (n=5) and Confocal Laser Scanning Microscopy (CLSM). Fluorescence images were qualitatively and semi-quantitatively analyzed using arbitrary units (ImageJ). Data were statistically evaluated with two-way ANOVA and Tukey’s test (α < 0.05).
Results: The results were: SU- 22.53(7.20)/ 16.03(5.22); BX- 25.09(9.77)/ 4.84(1.57); NT- 10.24(2.93)/ 22.29(25.16), considering S and E conditions respectively. SU performed similarly on both dentin, while BX demonstrated greater anti-proteolytic efficacy for E. For a correct interpretation, NT values did not differ between S and E, although E presented a higher mean value, probably due to the high variability of altered substrates.
Conclusions: The findings suggest that the technologies incorporated into UAs interacted with the dentin matrix metalloproteinase (MMP) activity, in which BX was more efficient to treat eroded dentin.