Degradation and Stabilization of Resin-Dentine Interfaces in Polymeric Dental Adhesives: An Updated Review

Abstract

Instability of the dentine-resin interface is owed to the partial/incomplete penetration of the resin adhesives in the collagen fibrils. However, interfacial hydrolysis of the resin-matrix hybrid layer complex activates the collagenolytic and esterase enzymes that cause the degradation of the hybrid layer. Adequate hybridization is often prevented due to the water trapped between the interfibrillar spaces of the collagen network. Cyclic fatigue rupture and denaturation of the exposed collagen fibrils have been observed on repeated application of masticatory forces. To prevent interfacial microstructure, various approaches have been explored. Techniques that stabilize the resin–dentine bond have utilized endogenous proteases inhibitors, cross linking agents’ incorporation in the exposed collagen fibrils, an adhesive system free of water, and methods to increase the monomer penetration into the adhesives interface. Therefore, it is important to discover and analyze the causes of interfacial degradation and discover methods to stabilize the hybrid layer to execute new technique and materials. To achieve a predictable and durable adhesive resin, restoration is a solution to the many clinical problems arising due to microleakage, loss of integrity of the restoration, secondary caries, and postoperative sensitivity. To enhance the longevity of the resin-dentine bond strength, several experimental strategies have been carried out to improve the resistance to enzymatic degradation by inhibiting intrinsic collagenolytic activity. In addition, biomimetic remineralization research has advanced considerably to contemporary approaches of both intrafibrillar and extrafibrillar remineralization of dental hard tissues. Thus, in the presence of biomimetic analog complete remineralization of collagen, fibers are identified.

Update on Dental Luting Materials

“…Similar to self-etching adhesive systems, the functional acidic monomers create a low pH and high hydrophilicity during the initial setting reaction. This gives the material the ability to wet and etch the tooth surface to facilitate a homogenous infiltration of the adhesive resin [ 96 ]. As the reaction proceeds, the acidic functional groups react with the calcium in the dental tissues and a range of metal oxides from ion-leachable inorganic fillers, resulting in a gradually increased pH and hydrophobicity [ 97 ].…”

Adhesion to enamel and dentine: an update

“…24 as this degradation process continues and the hydrophilic components of the bonding system dissolve, the previously resin-infiltrated collagen network could become exposed, making it vulnerable to further attack by collagenolytic enzymes. 25…”

Medical and Dental Applications of Titania Nanoparticles: An Overview

“…This occurs due to the collagenous, hydrophilic nature of the dentin structure and the breakage of the strong polymeric covalent bond between them through hydrolytic degradation. Eventually, the total failure of the adhesive bond to the dentin surface occurs [ 331 ]. The incorporation of TiO 2 NPs in adhesives to investigate their bonding to human teeth has been carried out [ 332 ].…”