Effect of Polyacrylic Acid Conditioning on the Longevity of Bonding of Self - Adhesive Resin Cement to Dentin

Bond Strength of Zirconia Ceramics to Dentin Using Two Resin Cements: Influence of Dentin Conditioning.. [DOI: 10.21203/rs.3.rs-3067702/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0]

Background Dentin adhesion has difficult challenge compared to enamel adhesion. The purpose of the current study was to assess the impact of different dentin conditioning methods and two different resin cements on bond strength of zirconia ceramics to dentin. Methods A total of 64 zirconia discs were fabricated using CAD/CAM technology according to the desired dimensions (8mm diameter ×3mm thickness). A total of 64molars mounted in plastic rings with acrylic resin were prepared by exposing flat coronal dentin surfaces by removing the occlusal enamel and superficial dentin. The prepared molars were divided into 4 main groups (n = 16) according to dentin surface treatment; Dentin left as cutted, treated with EDTA, treated with Polyacrylic Acid (PAA), treated with self-etch adhesive. Each main group was subdivided into 2 subgroups (n = 8) according to luting cement used. One of the subgroups, zirconia discs were bonded to conditioned dentin surface using adhesive resin cement (VITA ADIVA® F-CEM). The other subgroup was bonded using self-adhesive resin cement (Calibra®Universal). After bonding, all specimens were stored in water bath at 37⁰C for 6 months followed by 10.000 thermal cycles. After artificial aging, all bonded specimens underwent shear bond strength testing using universal testing machine. The data was parametric and normally distributed. Two-way ANOVA was used to test significant difference in shear stress between cements and between surface treatments followed by post hoc Tukey test for correction of p value resulted from multiple comparisons. P is significant if < 0.05 at confidence interval 95%. Results There was a significant difference in shear bond strength between surface treatments. The highest shear bond strength was reported with Self-etch adhesive, followed by PAA, then EDTA surface treatments, and the lowest shear bond strength was reported with as cutted dentin. Also,There was a significant difference between each two surface treatments except between PAA and EDTA for adhesive resin cement group. Conclusion Define dentin surface treatment with self etch adhesive is recommended before bonding zirconia restoration overall the conditioning materials, followed by PAA and EDTA. Specially with self-adhesive resin cement (Calibra universal cement).

Effect of Simultaneous Sintering of Bioglass to a Zirconia Core on Properties and Bond Strength

This study aimed to assess bioglass sintering to a zirconia core on surface properties and bonding strength to resin cement. Zirconia specimens were divided into four groups: G I: sintered; G II: bioglass modified zirconia (a bioglass slurry was sintered with zirconia at 1550 °C); G III: sandblasted using 50 μm Al₂O₃ particles; and G IV: Z-prime plus application. Surface morphology and chemical analysis were studied using a scanning electron microscope and energy-dispersive spectroscopy. Surface roughness was evaluated using a profilometer. Surface hardness was measured using an indentation tester. For the microshear bond strength test, resin cement cylinders were bonded to a zirconia surface. Half of the specimens were tested after 24 h; the other half were thermocycled (5-55 °C) for 1000 cycles. A shearing load was applied at a crosshead speed of 0.5 mm/min on a universal testing machine. Data were analyzed with ANOVA using SPSS software at (p < 0.05). Results: tThe mean surface roughness of G II was significantly higher than G I and G III. The microhardness of G II was significantly lower than all groups. For bond strength, there was no significant difference between groups II, III, and IV after thermocycling. Conclusions: Bioactive glass can increase the bond strength of zirconia to resin cement, and is comparable to sandblasting and Z-prime bonding agents.

Post-Space Treatment Influences the Bond Strength In Endodontically Treated Teeth: A Systematic Review and Meta-Analysis of In Vitro Studies

OBJECTIVES

This systematic review of in vitro studies investigated the influence of the post-space treatment used to remove the smear layer on the bond strength of the post to root canal dentin.

METHODS AND MATERIALS

In vitro studies included in this study were identified from PubMed/MEDLINE, Lilacs, and Scopus databases up until March 2019, without limits on publication year or language. Two reviewers independently selected the studies based on the inclusion and exclusion criteria, extracted the data, and evaluated the risk of bias of all studies. A random effects model was used for pairwise meta-analyses (control vs. post-space preparation groups) at a significance level of p<0.05.

RESULTS

Of the 2,832 potentially eligible studies, 453 studies were selected for full-text analysis, and 75 were included in this systematic review. Only one study was considered to have a low risk of bias. Overall, post-space treatment significantly improves the bond strength to root canal dentin (p<0.00001).

CONCLUSION

Post-space treatment has a positive influence on the bond strength of the post to root canal dentin. In this review, the post-space treatments that improve the adhesive resistance of the post were ethanol, sodium hypochlorite, and ethylene diamine tetra-acetic acid (NaOCl + EDTA), NaOCl + EDTA + ultrasound, erbium-doped yttrium aluminium garnet laser (Er:YAG laser), neodymium-doped yttrium aluminium garnet laser (Nd:YAG laser), and diode laser.