Long-Term Resin Bond to Densely Sintered Aluminum Oxide Ceramic

Effect of Surface Treatments on the Bond Strength to Turkom-Cera All-ceramic Material

AIM

The aim of this study was to evaluate the effect of surface treatments on shear bond strength (SBS) of Turkom-Cera (Turkom-Ceramic (M) Sdn. Bhd., Puchong, Malaysia) all-ceramic material cemented with resin cement Panavia-F (Kuraray Medical Inc., Okayama, Japan).

MATERIALS AND METHODS

Forty Turkom-Cera ceramic disks (10 mm × 3 mm) were prepared and randomly divided into four groups. The disks were wet ground to 1000-grit and subjected to four surface treatments: (1) No treatment (Control), (2) sandblasting, (3) silane application, and (4) sandblasting + silane. The four groups of 10 specimens each were bonded with Panavia-F resin cement according to manufacturer's recommendations. The SBS was determined using the universal testing machine (Instron) at 0.5 mm/min crosshead speed. Failure modes were recorded and a qualitative micromorphologic examination of different surface treatments was performed. The data were analyzed using the one-way analysis of variance (ANOVA) and Tukey honestly significant difference (HSD) tests.

RESULTS

The SBS of the control, sandblasting, silane, and sandblasting + silane groups were: 10.8 ± 1.5, 16.4 ± 3.4, 16.2 ± 2.5, and 19.1 ± 2.4 MPa respectively. According to the Tukey HSD test, only the mean SBS of the control group was significantly different from the other three groups. There was no significant difference between sandblasting, silane, and sandblasting + silane groups.

CONCLUSION

In this study, the three surface treatments used improved the bond strength of resin cement to Turkom-Cera disks.

CLINICAL SIGNIFICANCE

The surface treatments used in this study appeared to be suitable methods for the cementation of glass infiltrated all-ceramic restorations.

Extrusion shear strength between an alumina-based ceramic and three different cements

STATEMENT OF PROBLEM

Surface treatment is an essential step in bonding a ceramic to resin. Alumina ceramics are particularly difficult to prepare for adequate bonding to composite resin cements.

PURPOSE

The purpose of this study was to evaluate the bond strength between a densely sintered alumina ceramic and bovine dentin with 2 adhesive resin cements and a resin-modified glass ionomer cement using an extrusion shear strength test.

MATERIAL AND METHODS

Alumina cones (n=30), 4 mm in height, 3 mm in diameter at the small end, and with an 8-degree taper, were fabricated. Without any treatment, the cones were cemented in a standardized cavity in 2.5-mm-thick bovine dentin discs using 1 of 3 cement systems: Panavia F, RelyX ARC, or RelyX Luting. The cements were manipulated following the manufacturers' instructions. After 24 hours of storage at 37 degrees C, an extrusion shear test was performed in a universal testing machine at 0.5 mm/min until bonding failure. The data were analyzed using 1-way ANOVA and Tukey HSD test (alpha=.05). All fractured specimens were examined at x25 magnification and classified by fracture mode. Representative specimens were selected for SEM observation.

RESULTS

The highest strength values were obtained with Panavia F, and they were significantly higher (P<.05) than each of the other 2 cements, which were not significantly different from each other. Panavia F resulted in predominantly mixed failure and RelyX ARC and RelyX Vitremer showed primarily adhesive failure.

CONCLUSIONS

An MDP-containing adhesive system (Panavia F) provides better extrusion bond strength to a high-density alumina ceramic than a Bis-GMA resin luting agent system (RelyX ARC) or a resin-modified glass ionomer cement system (RelyX Luting).

Durability of the resin bond strength to zirconia ceramic after using different surface conditioning methods

OBJECTIVES

The purpose of this in vitro study was the evaluation of the bond strength and its durability of two composite resins to zirconia ceramic after using different surface conditioning methods.

METHODS

Plexiglas tubes filled with composite resin were bonded to zirconia ceramic discs (Cercon) which were either in their original state as supplied by the manufacturer only cleaned in isopropanol or were cleaned with an air-powder-water spray with sodium hydrocarbonate solution or were air abraded (50 microm Al(2)O(3)). Groups of 20 specimens each were bonded either with a conventional composite resin (Variolink II) or with a phosphate monomer (MDP)-containing resin (Panavia F) to the ceramic discs. Subgroups of 10 bonded specimens were stored in distilled water (37 degrees C) for either 3 days or for 150 days. Additionally, the 150 days specimens were thermal cycled 37,500 times. Statistical analyses were conducted with the Wilcoxon rank sum test adjusted by Bonferroni-Holm.

RESULTS

The initial tensile bond strength (TBS) for Variolink II ranged from 9.0 to 16.6 MPa and were significantly lower (p< or =0.05) than for Panavia F ranging from 18.7 to 45.0 MPa. Air abrasion resulted in significantly higher TBS (p< or =0.01) than the two other surface conditioning methods. After 150 days storage, only the air abraded specimens bonded with Panavia F showed high bond strengths of 39.2 MPa, whereas most other specimens debonded spontaneously or showed very low bond strengths.

SIGNIFICANCE

The use of the MDP-containing composite resin Panavia F on air abraded zirconia ceramic can be recommended as promising bonding method.

Integration of Composite and Ceramic Restorations in Tetracycline-Bleached Teeth: A Case Report

The success of an esthetic rehabilitation depends on the understanding of the patient's need and expectation. The management of patients with moderate to severe tetracycline-stained teeth is very challenging. Tooth whitening may be a valid alternative to more aggressive treatments; however, patients should be aware of the limitations of tooth whitening therapy. Clinicians may select differing treatment plans; tooth whitening can improve intrinsic discoloration in a way so that no further treatment is required. Once tooth whitening is completed, direct or indirect restorative procedures may be afforded to match the existing restoration with the bleached tooth structure. This article describes a conservative clinical approach to rehabilitate the smile of a patient with moderate to severe tetracycline-stained teeth using a combination of tooth whitening and direct composite and indirect porcelain restorations in the maxillary anterior segment.

CLINICAL SIGNIFICANCE

The combination of tooth whitening and adhesive restorations allows clinicians a significantly more conservative approach to intrinsically stained teeth; tooth preparation for porcelain veneers and porcelain-fused-to-metal and full-ceramic crowns can be restricted to conditions in which persistent tooth discoloration or significant loss of both dentin and enamel exists.

Fracture resistance of single-tooth implant-supported all-ceramic restorations: An in vitro study

STATEMENT OF PROBLEM

High-strength ceramic materials can be used to fabricate esthetic and stable implant-supported single-tooth restorations. No study was identified that compared the fracture resistance of individual components of single-tooth implant-supported all-ceramic restorative systems after artificial aging.

PURPOSE

The purpose of this in vitro study was to evaluate the fracture resistance of single-tooth implant-supported all-ceramic restorations consisting of alumina all-ceramic restorations on different implant abutments and to identify the weakest component of the restorative system.

MATERIAL AND METHODS

Forty-eight standardized maxillary central incisor alumina crowns (Procera) were fabricated for each of the 3 test groups (n = 16) (Control group Ti, titanium abutments; Group Al, alumina abutments; Group Zr, zirconia abutments) for the Replace implant system. The crowns were adhesively luted using a resin luting agent (Panavia 21) and artificially aged through dynamic loading and thermal cycling. Afterwards, all specimens were tested for fracture resistance using compressive load on the palatal surfaces of the crowns. Kruskal-Wallis analysis of variance and post hoc Wilcoxon rank sum tests were performed to test for differences in fracture resistance values (alpha = .05).

RESULTS

All test specimens survived the artificial aging process using simulated oral conditions. No screw loosening was recorded. The median fracture resistance was 1454 N, 422.5 N, and 443.6 N for groups Ti, Al, and Zr, respectively. Significant differences were found for the fracture resistance comparisons of group Ti with groups Al and Zr (Kruskal-Wallis test, P < .001). The test results for the comparison of groups Al and Zr were not significant.

CONCLUSION

All 3 implant-supported restorations have the potential to withstand physiologic occlusal forces applied in the anterior region.