Effect of Polymeric Microparticles Loaded With Catechin on the Physicochemical Properties of an Adhesive System

Abstract

SUMMARY The objective of this study was to synthesize and characterize epigallocatechin-3-gallate (EGCG)–loaded/poly(D-L lactide-co-glycolide) acid (PLGA) microparticles, evaluate their effects on degree of conversion and release assay of adhesives, and subsequently to examine the resin-dentin bond strength of two EGCG formulations (free EGCG or loaded into PLGA microparticles) applied as a pretreatment or incorporated into an adhesive system. The formulations were prepared according to a PLGA:EGCG ratio of 16:1 using the spray-drying technique. The size and polydispersity index were determined by light scattering in aqueous dispersion. The degree of conversion (%DC) and release assay were assessed by Fourier transform infrared spectroscopy and ultraviolet-visible spectrophotometer, respectively. Subsequently, 45 third molars were divided into five groups (n=9) according to the different EGCG application modes and prepared for bond strength testing in a universal testing machine. Results demonstrated no statistically significant difference among the DC means after the PLGA microparticles were loaded with EGCG. For the release assay, the 1.0% PLGA/EGCG group presented better results after being elected for use in the bond strength test. The resin-dentin bond strengths of the experimental groups after 12 months of water storage were significantly higher than in the control group. EGCG could improve the durability of the resin-dentin bond over time and promote a new era for adhesive dentistry with the concept of controlled release.

Effects of Plant Extracts on Dentin Bonding Strength: A Systematic Review and Meta-Analysis

“…Another important plant extract being intensely investigated is epigallocatechin-3-gallate (EGCG) ( Du et al, 2012 ; Santiago et al, 2013 ; Yang et al, 2016 ; Yu et al, 2017 ; Albuquerque et al, 2019 ; Costa et al, 2019 ; Fialho et al, 2019 ; Landmayer et al, 2020 ; Zhang et al, 2020 ). It is one of the flavanols in tea, also known as catechins ( Tachibana, 2011 ).…”

“…The similarity of chemical structure with other flavanols like PA makes it capable of enhancing the mechanical strength of collagen. The addition of EGCG directly into adhesives has been proven to preserve the bond strength after different ageing methods ( Du et al, 2012 ; Yu et al, 2017 ; Albuquerque et al, 2019 ). The result of EGCG primer showed no negative influence on immediate bond strength ( Zhang et al, 2020 ).…”

Polyphenols in Dental Applications

“…At concentrations of 0.5% and 1% (w/v), EGCG incorporated in an adhesive resin could increase the bond strength values and the longevity of adhesive-dentin bond for 6-12 months [44,45]. In contrast to the previous investigation, the addition of 0.01 and 0.1% (w/v) of EGCG to adhesive-resin compounds did not affect the resin-dentin bond, but could reduce the solubility of the adhesive-resin in water [42].…”

Application of green tea extracts epigallocatechin‐3‐gallate in dental materials: Recent progress and perspectives

“…EGCG can not only be directly mixed with adhesive in the form of a solution but also mixed with it after being loaded by microparticles. Albuquerque, N. et al produced poly (L‐lactic acid) (PLGA) microparticle loaded with EGCG, demonstrating that the resin‐dentin bond of the adhesive added with the microparticles was significantly higher than those of the control group after 12 months (Albuquerque et al, 2019). Similarly, the biocompatibility of the adhesive should be taken seriously.…”

“…The application of microparticles loaded with EGCG provides a new strategy for prosthetic dentistry. However, some question needs to be solved, such as the uncertain amount of EGCG release, the methodology and technology which need to be improved, and the interaction between these modified materials and dental pulp (Albuquerque et al, 2019; Hu et al, 2013). More clinical in vivo trials need to be carried out before EGCG can be applied to the patient's teeth.…”