Improvement of enamel bond strengths for conventional and resin-modified glass ionomers: acid-etching vs. conditioning

Abstract

Abstract:Objective: This study deals with the effect of phosphoric acid etching and conditioning on enamel micro-tensile bond strengths (μTBSs) of conventional and resin-modified glass ionomer cements (GICs/RMGICs). Methods: Forty-eight bovine incisors were prepared into rectangular blocks. Highly-polished labial enamel surfaces were either acid-etched, conditioned with liquids of cements, or not further treated (control). Subsequently, two matching pre-treated enamel surfaces were cemented together with one of four cements [two GICs: Fuji I (GC), Ketac Cem Easymix (3M ESPE); two RMGICs: Fuji Plus (GC), RelyX Luting (3M ESPE)] in preparation for μTBS tests. Pre-treated enamel surfaces and cement-enamel interfaces were analyzed by scanning electron microscopy (SEM). Results: Phosphoric acid etching significantly increased the enamel μTBS of GICs/RMGICs. Conditioning with the liquids of the cements produced significantly weaker or equivalent enamel μTBS compared to the control. Regardless of etching, RMGICs yielded stronger enamel μTBS than GICs. A visible hybrid layer was found at certain enamelcement interfaces of the etched enamels. Conclusions: Phosphoric acid etching significantly increased the enamel μTBSs of GICs/RMGICs. Phosphoric acid etching should be recommended to etch the enamel margins before the cementation of the prostheses such as inlays and onlays, using GICs/RMGICs to improve the bond strengths. RMGICs provided stronger enamel bond strength than GICs and conditioning did not increase enamel bond strength.

Synergistic effects of titanium dioxide and cellulose on the properties of glassionomer cement

“…With respect to the shear bond strengths of the GICs with extracted human teeth, studies have shown that phosphoric acid etching can dramatically increase the enamel micro-tensile bond strengths (μTBSs) of conventional GICs and resin-modified GICs 39) . Porous structures may be formed on the enamel surface after etching.…”

Bond strength and microleakage of self-adhesive and conventional fissure sealants

“…Although GIs can bond to enamel even in the presence of a smear layer, bond strength can be increased by pretreatment with a surface conditioner (such as PA, citric acid, maleic acid, or polyacrylic acid) to remove the smear layer 32,33) . PA etching of the tooth surface provides good wetting of the surface and enables GIs to chemically interact with the mineral phase of enamel by ionic 34) interaction. Polyalkenoic acids have been shown to be irreversibly adsorbed onto hydroxyapatite surfaces.…”

Analysis of the surface roughness and microhardness of dental restorative materials exposed to heat sources and cold temperatures for human identification purposes

“…Bovine teeth make it easier to standardize the samples, with a lower risk of infection, besides the bioethical issues (Wang et al 2012;Zhang et al 2013). They present similarities to the human dental tissues, particularly concerning the orientation of the enamel prisms, an equivalent percentage by weight of calcium, and protein matrix composed of the same amino acids (Wang et al 2012).…”

“…As regards dentin, there are some controversies relative to the similarity between the teeth of both species. However, there is a consensus in the literature that in shallow cavities, with a depth of 2 mm, bovine dentin has been shown to be feasible for adhesion, providing adequate bond strength when compared with human dentin (Zhang et al 2013).…”