The Effects of Tooth Preparation Cleansing Protocols on the Bond Strength of Self-adhesive Resin Luting Cement to Contaminated Dentin

Abstract

SUMMARYThis in vitro study evaluated the bond strength of a self-adhesive luting cement after using four different techniques to remove surface contamination on dentin. Extracted human molars were flattened to expose the dentin surface and prepared for full crown preparation. Acrylic temporary crowns were fabricated and placed using temporary cement. The specimens were stored at room temperature with 100% relative humidity for seven days. Following removal of the temporary crowns, the specimens were randomly divided into four groups, and excess provisional cement was removed with 1) a hand instrument (excavator), 2) prophy with a mixture of flour pumice and water 3) aluminous oxide abrasion with a particle size of 27 µm at 40 psi and 4) aluminous oxide abrasion with a particle size of 50 µm at 40 psi. The microstructure morphology of the tooth surface was evaluated and residual materials were detected using SEM and EDS analysis of randomly selected specimens. The ceramics were treated with 9.5% hydrofluoric acid-etch and silanized to the prepared dentin prior to cementing with self-adhesive resin cement (RelyX Unicem, 3M ESPE). The shear bond strength was determined at a crosshead speed of 0.5 mm/minute. The results were analyzed with one-way ANOVA, followed by Tukey's test. Particle abrasion treatment of dentin with an aluminous oxide particle provided the highest values of bond strength, while hand instrument excavation was the lowest (p<0.05). Aluminous oxide particle size did not significantly influence the bond strength at 40 psi. The use of low pres- Y Chaiyabutr • JC Kois Clinical RelevanceTooth preparation cleaning protocol surface management with lower pressure aluminous particle abrasion provides a significant improvement in bond strength to dentin.

Effect of Dentin-cleaning Techniques on the Shear Bond Strength of Self-adhesive Resin Luting Cement to Dentin

“…10 Specimens abraded with aluminum oxide showed the highest shear bond strength values compared with any other cleansing technique. This result is consistent with a previous study 21 showing significantly higher bond strength when aluminum oxide particles were used for dentin surface treatment before indirect restorations were cemented with a self-adhesive resin luting cement, compared with pumice and hand instruments. In their study, tooth surfaces were treated with 50 and 27 lm aluminum oxide particles.…”

“…According to the information available on selfadhesive cement, the presence of water, phosphoric acid, and methacrylate monomer will demineralize the smear layer and the underlying dentin, while simultaneously infiltrating the porous dentin surface, as a result of its hydrophilic properties and the neutralization of acid that occurs as polymerization progresses 21 ; however, insufficient demineralization and limited resin infiltration have been observed. 5,14,18,31 In the present study, 40% polyacrylic acid was used to verify whether this weak acid would provide further demineralization to enhance bonding.…”

The Efficacy of Different Sealer Removal Protocols on Bonding of Self-etching Adhesives to AH Plus–contaminated Dentin

“…Bonding of self-etch adhesives/resin cements is compromised when they are applied to oil-contaminated or temporary cement-contaminated dentin (20,21). From a practical perspective, excess unset sealers that are present around filled canal orifices are smeared over the pulp chamber dentin during the application of self-etching adhesives.…”

The Effect of Tooth-preparation Cleansing Protocol on the Bond Strength of Self-adhesive Resin Cement to Dentin Contaminated with a Hemostatic Agent

“…13 Recently, the use of a low-pressure aluminum oxide particle abrasion has been reported as an effective mechanical cleansing surface treatment in removing residual provisional luting agents. 14 The microparticle abrasion technique has been described as an alternative method of tooth structure pretreatment that minimizes the vibration, pressure and heat associated with rotary cutting instruments. Kinetic energy, generated by a high-velocity stream of aluminum oxide particles, is used to prepare dentin and enamel, while having only a slight impact on softer materials, such as gingival tissue.…”