Effect of dentinal surface preparation on the bonding of self-adhesive luting cements

Abstract

The purpose of the present study was to evaluate the bond strength and the interaction morphology of self-adhesive resin luting cements (SLCs) to dentin prepared with different methods. Four SLCs were used: RelyX U100 ® , RelyX U200 ® , Clearfil SA Luting ® , and SmartCem2 ® . A flat dentin surface of 40 human molars was exposed and each tooth was sectioned in four tooth-quarters, which were distributed into four groups according to the SLC used to cement indirect resin composite restorations. The tooth-quarters of each group were then distributed in four subgroups according to the method used for dentin preparation: flat-ended cylindrical fine-grit diamond, flat-ended cylindrical median-grit diamond, flat-ended cylindrical plain-cut tungsten carbide, or abraded with #600-grit SiC paper (control). The restored toothquarters were sectioned to obtain beams (0.8 mm 2 ) and submitted to the microtensile bond strength test (n = 10). The results were analyzed using two-way ANOVA/ Tukey (α = 0.05). Forty-four additional teeth were used for micromorphological investigation of the SLC/dentin interface and of the topographic aspect of the dentin surfaces after application of the SLCs. Only the bond strength of RelyX U200 was significantly influenced by the surface preparation. No interference was identified on the micromorphological aspect of the bonding interfaces. The topographic investigation of the dentinal surfaces showed that the SLCs were not able to effectively remove the smear layer and etch the underlying dentin, irrespective of the preparation method. So, the interference of the dentin preparation on the bond strength of SLCs is material dependent, but don't influence the micromorphologic aspect of the interaction zone.

Effects of Polymerization Mode and Interaction with Hydroxyapatite on the Rate of pH Neutralization, Mechanical Properties, and Depth of Cure in Self-Adhesive Cements

“…For that, as previously pointed out, it is imperative to have a formula in which the polymerization reaction proceeds in an acidic environment without interfering in the end conversion. 5 17 The polymerization setting reaction is claimed to be responsible for pH neutralization in the polymerizing material, 1 which plays an important role on the immediate and long-term mechanical properties of the material. 11 So, the study of such pH neutralization over time is imperative for a better understanding of the properties of each commercial SRC.…”

Effect of dentin surface roughness on the shear bond strength of resin bonded restorations

“…The degree to which the adhesive moistens the dentin surface depends on the cement viscosity, contact angle between the two surfaces, topography of dentin surface, and the grit size of the cutting instrument. 15 16 17 18 19 20 When the dentin is cut, a smear layer of different thickness and density is formed on it, whose morphology and characteristics depend on the grit size of burs or abrasive instruments. Accordingly, the greater the grit size of the abrasive rotary instrument, the thicker the smear layer.…”

Influence of a propolis-based irrigant solution on gap formation and bond strength of posts bonded to root canal dentin using different resin cements

“…Since self-adhesive cements require greater and longer contact with the dental hard tissues in order to react with hydroxyapatite, their application is facilitated by automix delivery system; this helps to diffuse and to decalcify the underlying dentin, thus allowing a better monomer dentinal interaction with the dental tissues 34,35) . It has also been stated that such procedures allow the formation of secondary chemical reactions between the material and hydroxyapatite 36) .…”