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Published on: December 20, 2024
Effect of dentin biomodification delivered by experimental acidic and neutral primers on resin adhesion
Lívia Tosi Trevelin1, Yvette Alania2, Mathew Mathew2
1Department of Restorative Dentistry, College of Dentistry, University of Illinois at Chicago, Chicago, IL, USA; Department of Operative Dentistry, College of Dentistry, University São Caetano do Sul, USCS, SP, Brazil.
Objectives:
Proanthocyanidins (PACs) are biocompounds mimicking native collagen cross-links. The effective and practical delivery of any biocompound is pivotal for clinical usage. The aim was to investigate the dentin biomodification and effective formation of dentin-resin biointerfaces of two highly bioactive PAC-rich extracts, Vitis vinifera (Vv) and Camellia sinensis (Cs), delivered using neutral (NP) or acidic (AP) rinse-out primer approaches.
Methods:
The depth of dentin demineralization (optical profilometry), dentin biomodification (apparent modulus of elasticity, collagen auto-fluorescence) and properties of dentin-resin interfaces (microtensile bond strength - μTBS, and micro-permeability) were investigated. NP consisted of either 15% Vv or Cs applied for 60 s after surface etching; while AP contained 15% Vv or Cs in either 35% glycolic acid or tartaric acid applied for 30 s or 60 s. Data were analyzed using ANOVA and post-hoc tests (α = 0.05).
Results:
The depth of demineralization was statistically higher when applied for 60 s, regardless of rinse-out primer approach (p < 0.001). Compared to the AP strategy, NP exhibited statistically higher apparent modulus of elasticity, regardless of PAC extract (p < 0.001). Highest μTBS were obtained for NPVv, which were statistically similar to APGAVv, when applied for 60 s (p < 0.001); both resulted in a dramatic decrease of the interfacial permeability. NPCs group showed the lowest μTBS (p < 0.001).
Conclusions:
A combination of high bond strength and low micro-permeability can be accomplished using glycolic acid with the mid- and high-PAC oligomer enriched extract (Vv). Cs extract containing mostly catechins and dimeric PACs, was found unsuitable for resin-dentin adhesion despite exhibiting high initial dentin biomodification.
Clinical Significance:
This study provides a new conceptual delivery of PAC-mediated dentin biomodification and conservative dentin surface etching using rinse-out primers. The strategy requires a specific combination of PAC source, α-hydroxy acid, and application time.
