Influence of erbium: Yttrium-aluminum-garnet laser, potassium titanyl phosphate laser irradiation, and acid etch on microtensile bond strength of adhesives

Abstract

A dhesion to dental hard tissues can be achieved by the use of bonding agents that promote a micromechanical interlock with both enamel and dentine. Bonding to dentin depends on the infi ltration of synthetic adhesive monomers into a biological, collagenrich substrate to form a hybrid layer. Nevertheless, dentine adhesives have brought about major changes in restorative procedures. The evolution of adhesive systems that has been designed to achieve the bond of the adhesive to the dental structure has improved the clinical performance of restorations because of better adaptation to cavity walls. [1,2] Consequently, there has been a decrease in microleakage and secondary caries.Most of the adhesive systems include an acid-etching procedure to provide better adhesion to dental substrate since it was intended for use in pretreatment of dental hard tissues. Acid-etching promotes increased bond strength to dental hard tissues, but acid-etching has some disadvantages like; making the dental substrate more prone to acid attacks, swallowing, aspiration, and burning of the tongues, increased dentin permeability increased diffusion coeffi cient, easy penetration of bacteria and this may cause to hypersensitive dentine. [3][4][5][6] The disadvantages of the acid-etching thought researchers that laser etching may be alternative to acid-etching. [5,7] Laser appliances have brought indisputable benefits to modern dentistry. [8,9] They minimize the loss of healthy tissue and promote a great deal of comfort to patients.

Comparative Study of Acid Etching on Dental Enamel

“…The type of drying will be reduced if hydrophilic / hydrophobic monomers are used, which require a slight degree of moisture of the substrate for effective adhesion. Conditioned enamel allows its wetting and impregnation micropores with resin-monomer, which once polymerized will generate tab-like extensions at micro-cavities level that will retain the adhesive layer, forming a hybrid layer between the enamel and the adhesive [2,10].…”

“…At the same time, acid etching is preceded by a step consisting in the mechanical preparation of the enamel by means of diamond drills (carries removal; bevelling of cavity edges, etc.). Both procedures make their mark on the tooth load-bearing structure, creating injuries at this level, injuries that, in vivo, need months to be remedied [3,8,10]. All these make it possible to impregnate the tissue with a monomer that will be retained inside the micropores created when it changes its aggregation state [8].…”

“…In order to prove this relationship, three groups were used in the study: G1 -acid etching for 15 s; G2 -acid etching for 5 seconds; G3 -acid etching for 5 seconds + light of the light-curing lamp. The result of the study showed that using the light-curing lamp technique, the acid etching time is reduced to just 5 s without endangering the quality of the work done [10,11].…”