Effect of metal priming agents on bond strength of resin-modified glass ionomers joined to gold alloy

Influence of polymerization methods and priming agents on the bond strength between resin luting agents and gold alloy

PURPOSE

To evaluate the influence of polymerization methods and a metal priming agent on the bond strength between gold alloy for metal ceramic restorations and dual-cure-type resin luting agents, and on the strength and hardness of the luting agents.

METHODS

A total of 154 disks cast by a gold alloy were treated with or without a metal priming agent. One of the three luting agents was applied on the disk. The luting agent was either chemically or dual-polymerized. The shear bond strength was measured both before and after thermocycling. In addition, scanning electron microscope (SEM) observation, flexural strength test, and Knoop hardness test were performed.

RESULTS

Significant differences among the luting agents were observed in terms of bond strength and flexural strength. Significant differences between chemically and dual-polymerized luting agents were observed regarding shear bond strength, flexural strength, and Knoop hardness before thermocycling. The application of the priming agent was effective only for a luting agent.

CONCLUSION

Both bond strength and flexural strength differed among three luting agents. The effect of the priming agent on bond strength differed among the luting agents. Both the bond and flexural strength of a chemically polymerized luting agent differed before or after thermocycling.

The Effect of Mechanical and Chemical Surface Preparation Methods on the Bond Strength in Repairing the Surface of Metal-Ceramic Crowns with Composite Resin: a Systematic Review and Meta-Analysis

The aim of this study was to find the most effective surface preparation methods to enhance the bond strength between the composite resin and surface remaining from ceramic fracture. In this systematic review and meta-analysis, 39 studies were examined. The information related to the studies was extracted and categorized based on the type of the substrate material and applying or not applying thermal cycles (p<0.05). In the meta-analysis of substrate metal-ceramic samples without aging, application of air abrasion resulted in a significant increase of the bond strength to composite resin when using chemical compounds of the group without the mentioned functional monomers. Application of mechanical and chemical surface preparation methods can result in enhanced bond strength of the composite to the substrate material, which depends on the type of substrate material.

Tensile Strength of Resin Cements Used with Base Metals in a Simulating Passive Cementation Technique for Implant-Supported Prostheses

Abstract The aim of this study was to analyze the tensile strength of two different resin cements used in passive cementation technique for implant-supported prosthesis. Ninety-six plastic cylinders were waxed in standardized forms, cast in commercially pure titanium, nickel-chromium and nickel-chromium-titanium alloys. Specimens were cemented on titanium cylinders using self-adhesive resin cement or conventional dual-cured resin cement. Specimens were divided in 12 groups (n=8) in accordance to metal, cement and ageing process. Specimens were immersed in distilled water at 37 °C for 24 h and half of them was thermocycled for 5,000 cycles. Specimens were submitted to bond strength test in a universal test machine EMIC-DL2000 at 5 mm/min speed. Statistical analysis evidenced higher tensile strength for self-adhesive resin cement than conventional dual-cured resin cement, whatever the used metal. Self-adhesive resin cement presented higher tensile strength compared to conventional dual-cured resin cement. In conclusion, metal type and ageing process did not influence the tensile strength results.

Repair Technique for Fractured Implant-Supported Metal-Ceramic Restorations: A Clinical Report

The fracture of porcelain structures have been related in either natural dentition or implant-supported restorations. Techniques using a composite resin or indirect methods can be used. This article presents a porcelain fracture on implant-supported metal-ceramic restoration. IPS Empress e.max laminate veneer restoration was used to repair the fracture. With this technique, it was possible to restore aesthetics and function, combined with low cost and patient satisfaction.

In Vitro Shear Bond Strength of Three Self-adhesive Resin Cements and a Resin-Modified Glass Ionomer Cement to Various Prosthodontic Substrates

Objective

To evaluate the shear bond strength (SBS) of three self-adhesive resin cements and a resin-modified glass ionomer cement (RMGIC) to different prosthodontic substrates.

Materials and Methods

The substrates base metal, noble metal, zirconia, ceramic, and resin composite were used for bonding with different cements (n=12). Specimens were placed in a bonding jig, which was filled with one of four cements (RelyX Unicem, Multilink Automix, Maxcem Elite, and FujiCEM Automix). Both light-polymerizing (LP) and self-polymerizing (SP) setting reactions were tested. Shear bond strength was measured at 15 minutes and 24 hours in a testing device at a test speed of 1 mm/min and expressed in MPa. A Student t-test and a one-way analysis of variance (ANOVA) were used to evaluate differences between setting reactions, between testing times, and among cements irrespective of other factors. Generalized linear regression model and Tukey tests were used for multifactorial analysis.

Results

Significantly higher mean SBS were demonstrated for LP mode relative to SP mode (p&lt;0.001) and for 24 hours relative to 15 minutes (p&lt;0.001). Multifactorial analysis revealed that all factors (cement, substrate, and setting reaction) and all their interactions had a significant effect on the bond strength (p&lt;0.001). Resin showed significantly higher SBS than other substrates when bonded to RelyX Unicem and Multilink Automix in LP mode (p&lt;0.05). Overall, FujiCEM demonstrated significantly lower SBS than the three self-adhesive resin cements (p&lt;0.05).

Conclusions

Overall, higher bond strengths were demonstrated for LP relative to SP mode, 24 hours relative to 15 minutes and self-adhesive resin cements compared to the RMGICs. Bond strengths also varied depending on the substrate, indicating that selection of luting cement should be partially dictated by the substrate and the setting reaction.

A study of self-adhesive resin cements for bonding to silver-palladium-copper-gold alloy -- effect of including primer components in cement base

This study investigated the efficacies of adhesive resin cements (Clearfil SA Luting, Maxcem, G-CEM, RelyX Unicem Clicker, Vitremer Paste) for bonding to Ag-Pd-Cu-Au alloy not surface-pretreated with metal primer. For control, Panavia F 2.0 -developed for use with a proprietary metal primer, Alloy Primer- was tested with and without metal primer application. Pairs of alloy disks (10.0 and 8.0 mm in diameters, 3.0 mm thickness) were air-abraded with alumina and bonded with one of the cements. Shear bond strengths (SBSs) were measured before and after 50,000 times of thermocycling. Among Maxcem, RelyX Unicem Clicker and the control, there were no statistical differences in SBS before and after thermocycling. After thermocycling, Clearfil SA Luting exhibited the highest SBS among all the cements. Results showed that Clearfil SA Luting, Maxcem, and RelyX Unicem Clicker were efficacious for bonding to Ag-Pd-Cu-Au alloy after air abrasion surface treatment for the latter.

Evaluation of a newly developed polymethyl methacrylate powder for brush-dip technique

PURPOSE

The aim of this study is to evaluate a newly developed polymethyl methacrylate (PMMA) powder.

METHODS

The particle size distribution, surface area, and particle shape of both new and traditional powders were compared. The shear bond strength of the resin cement with the new powder to a silver-palladium-copper-gold alloy was determined and compared to that for a cement with the traditional powder. Also, the weight of mixture held by the brush at one time of both powders was also calculated and compared as an index of mixability.

RESULTS

The surface area of the new powder was smaller than that of the traditional powder, while the particles size distributions were similar. The new powder included various-sized spherical particles as well as irregular particles, while the traditional powder consisted of only irregular particles. The new powder showed significantly higher mixability, although its bond strength was not significantly different from that of traditional powder.

CONCLUSION

The results of this study show that the interminglement of spherical and irregular particles cannot influence the bond strength to the alloy but is helpful to improve the working properties.