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Bonding of resin composite luting cements to zirconium oxide by two air-particle abrasion methods.

OBJECTIVE This study evaluated the shear bond strength of two resin composite luting cements to zirconium oxide ceramic substrate using two air-particle abrasion methods. METHODS Two resin composite cements, RelyX Unicem (3M ESPE) and Panavia F (Kuraray), each with an acidic composition, were used in combination with a zirconium oxide (DCS Dental AG) substrate containing Al2O3 and SiO2 (Rocatec system, 3M ESPE) and two air-particle abrasion methods. The shear bond strength of the resin composite cement to the substrate was tested after the samples were either water-stored for one week or thermocycled following 24 hours of water storage. RESULTS The RelyX Unicem resin composite cement specimens with the Rocatec treatment (20.9 +/- 4.6 Mpa and 20.1 +/- 4.2 MPa, respectively, n = 12) demonstrated the highest shear bond strength. Alternatively, the lowest values were obtained for the Panavia F resin cement samples, with Al2O3 air-particle abrasion in both storage conditions, water storage for one week (17.7 +/- 8.9MPa) or thermocycling after 24 hours of water storage (16.3 +/- 4.9 MPa). Neither storage condition or particle abrasion system significantly affected shear bond strengths (ANOVA, p > 0.05). CONCLUSION It was concluded that two different surface conditioning methods and storage conditions did not significantly affect the bonding properties of Panavia F and RelyX Unicem resin composite luting cements to Zirconia.

Intra‐oral adhesive systems for ceramic repairs: a comparison

The aim of this investigation was to compare the bond strength of restorative composite resin to dental ceramic conditioned with primers and adhesives of various commercial repair kits. Three intra‐oral ceramic repair systems—Silistor (Heraeus Kulzer), Cimara (Voco), Ceramic Repair (Vivadent)—were used on all‐ceramic (IPS Empress 2, Ivoclar‐Vivadent) substrate. Shear bond strength of restorative composite resin to substrate was tested after thermocycling and without thermocycling (n=10). Substrate surfaces of the specimen after loading were examined microscopically (SEM). The highest bond strengths in both water‐stored (7.0±5.7 MPa) and thermocycled conditions (2.5±1.8 MPa) were obtained with the Vivadent repair system, while the lowest values were observed with the Cimara system (0.6±1.4 MPa and 0.0±0.0 MPa, respectively). Shear bond strengths appeared to be significantly affected by thermocycling (ANOVA, P<0.05). It is concluded that there are significant differences in the bond strengths of resin composites and ceramic substrate. The roughened surface does not necessarily provide a better bond strength; the bond strength of composite decreases with storage in water and after thermocycling. Bond strength values were generally low for all of the tested materials.

Bond Strength of Glass-Fiber Post to Dentine after some Treatment Methods

The purpose of this study was to evaluate the effects of various root canal treatment methods on bonding strength of a glass-fıber post to root canal dentin. 60 human maxillary anterior teeth were prepared with ParaPost (Coltène) up to diameter of 1.75 mm with drills of 1.14, 1.25, 1.40, 1.50 and 1.75 mm from 1 mm coronal level of apices. The upper surfaces of polished areas were ground to acquire correct angle with the long axis of drills and the specimens were divided into 6 groups (n=10). Glass-fiber posts (1.5mm) (everStick POST, StickTech) were cemented with a dual-cure composite resin cement (ParaCem, Coltène) after following treatment methods. (Group 1) 0.9% isotonic NaCl solution (control), (Group 2) 2.5% NaOCl + Er:YAG Laser (Kavo K-E-Y), (Group 3) 2% Chlorhexidine + Er:YAG Laser , (Group 4) Slurry Bioactive Glass Granules (Vivoxid), (Group 5) Silane-based Primer (3M, ESPE, RelyX) + Er:YAG Laser, (Group 6) Slurry Bioactive Glass Granules + Silane-based Primer + Er:YAG Laser. From each root, two disks of 2 mm thickness was obtained. The push-out test was carried out by using a universal testing device (Lloyd LRX) with a loading tip (diameter 1.7 mm, crosshead speed of 1.0 mm/min) until loosening of the post. Statistical analysis was performed using ANOVA followed by post-hoc comparisons (Tukey B, p<0.05). Root canals were evaluated by SEM. Bond strength of fiber posts were significantly affected by the type of treatment (p<0.05). The highest bond strength was observed in Group 5, whereas the lowest bond strength values were recorded with the Group 3. Bond strength of glass-fiber post to root canal dentin was affected by treatment method. Treatment with laser and Bioactive Glass Granules in combination of using silane yielded the highest bond strength.

Effects of Non-Silanized and Silanized Glass Particles on the Physical Properties on Denture Base Materials

The purpose of this study was to evaluate the effects of silanization of the glass on denture base materials and to evaluate different types of glasses. A total of 136 Poly(methyl methacrylate) (PMMA) (Palapress – Heraeus Kulzer) blocks were prepared in dimensions of 65mm x 10mm x 3mm. PMMA blocks were modified by different ratios of non-silanized and silanized Bioactive Glass Granules (BAG) (Vivoxid) and Inert Glass Granules (IG) (Vivoxid). The blocks were polished under water cooling and divided into 17 groups. (Group 1) No glass (control), (Group 2-5) 3-6-9-12% non-silanized BAG, (Group 6-9) 3-6-9-12% silanized BAG, (Group 10-13) 3-6-9-12% non-silanized IG, (Group 14-17) 3-6-9-12% silanized IG. The specimens were stored in distilled water and weighed (Mettler, Toledo) in days of 1, 2, 3, 7, 14, 21, 30, 45, 60. After water sorption test, the specimens were dried under 80°C and weighed in days of 0, 1, 2, 3, 5, 7, 9 for calculating the solubility values. Statistical analysis was performed using analysis of variance (ANOVA) followed by post-hoc comparisons (Dunnett T3, p<0.05). Water sorption and solubility values were significantly affected by the type and silanizaion of the glass (p<0.05). The highest water sorption value was observed in 12% silanized IG group (1,83±0,04%), whereas the lowest sorption values were recorded with 12% non-silanized BAG group (1,21±0,07%). Contrarily, The highest solubility value was observed in 12% non-silanized BAG group (0,98±0,03%), whereas the lowest solubility values were recorded with 12% non-silanized BAG group (0,34±0,03%). Water sorption and solubility values were affected by the type and silanization of the glass. Silanization improved the physical properties of the glass as well as the properties of the denture base material.