Mechanical-physicochemical properties and biocompatibility of catechin-incorporated adhesive resins

Abstract

Several anti-proteolytic dentin therapies are being exhaustively studied in an attempt to reduce dentin bond degradation and improve clinical performance and longevity of adhesive restorations.ObjectivesThis study assessed the effect of epigallocatechin-3-gallate (EGCG) on long-term bond strength when incorporated into adhesives.Material and MethodsAdhesive systems were formulated with EGCG concentrations of 0 wt%: (no EGCG; control); 0.5 wt% EGCG; 1.0 wt% EGCG, and 1.5 wt% EGCG. Flexural strength (FS), modulus of elasticity (ME), modulus of resilience (MR), compressive strength (CS), degree of conversion (DC), polymerization shrinkage (PS), percentage of water sorption (%WS), percentage of water solubility (%WL) and cytotoxicity properties were tested. Dentin microtensile bond strength (µTBS) was evaluated after 24 h and again after 6 months of water storage. The adhesive interface was analyzed using scanning electron microscopy (SEM).ResultsNo significant differences were found among the groups in terms of FS, ME, MR, CS and PS. EGCG-doped adhesives increased the DC relative to the control group. EGCG concentrations of 1.0 wt% and 0.5 wt% decreased the WS of adhesives. WL decreased in all cases in which EGCG was added to adhesives, regardless of the concentration. EGCG concentrations of 1.0 wt% and 0.5 wt% reduced cytotoxicity. EGCG concentrations of 1.0 wt% and 0.5 wt% preserved µTBS after 6 months of storage, while 1.5 wt% EGCG significantly decreased µTBS. SEM: the integrity of the hybrid layer was maintained in the 0.5 wt% and 1.0 wt% EGCG groups.ConclusionEGCG concentrations of 1.0 wt% and 0.5 wt% showed better biological and mechanical performance, preserved bond strength and adhesive interface, and reduced cytotoxicity.

Antibacterial and Bonding Properties of Universal Adhesive Dental Polymers Doped with Pyrogallol

“…All the adhesives produced a hybrid layer, some resin tags that infiltrated into dentinal tubules, and a continuous adhesive layer without voids. In accordance, Fonseca et al [ 29 ] reported a thin adhesive layer and tags infiltration into dentinal tubules at 24 h after the use of an adhesive modified with different weight percentages of ECGC. All adhesive groups dissolved the smear layer and allowed adhesive tags to infiltrate into the dentin structure.…”

“…PY powder was placed using a spatula and was weighted using a high-precision balance (Ohaus, Pioneer Analytical, Nänikon, Switzerland). Subsequently, the PY powder (0.5% and 1%) was added to the adhesive in the Eppendorf tube and mixed using a high shear mixer (Fisher Scientific, Illkirch, France) in a dark room at 2000 rpm for 10 min [ 29 ] in order to get a well-mixed PY–adhesive solution. The homogenization of the PY resin and complete dissolution were confirmed and it was used only if no crystals were observed under an optical stereomicroscope [ 30 , 31 ].…”

Antimicrobial evaluation, degree of solubility, and water sorption of universal dental adhesive incorporated with epigallocatechin-3-gallate: An In-vitro study

“…When altered, properties such as sorption and solubility can structurally modify adhesive systems, negatively affecting their performance and function. [28] Self-etching adhesives generally exhibit sorption and solubility in high water due to the incorporation of acid monomers into their composition. [11] Fonseca et al (2019) show that ECGC incorporation at a concentration of 0.5 wt% results in lower solubility of the template adhesive.…”

Polyphenols in Dental Applications

“…In addition to those properties, EGCG was incorporated in dental adhesive-resins for its inhibitory effects of matrix-metalloproteinases (MMPs) and cysteine cathepsins. Indeed, those proteins are major players in the degradation and perturbation of the resin-dentin interface [42,43].…”

“…The dental adhesive-resin incorporates many toxic compounds such as Bis-GMA, TEGDMA, and Bis-phenol A [47]. Fonseca et al [43] demonstrated that the presence of 0.5-1% (w/w) of EGCG in the adhesive-resin could reduce the toxicity, reduce the solubility and the water sorption of this adhesive. These concentrations (0.5-1%) could maintain the hybrid layer and preserve the bond strength over time.…”