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Purpose: To evaluate the efficacy of different surface treatments on the bond strength of polyetherketoneketone (PEKK) to ceramic materials. Materials and Methods: PEKK test specimens were separated into four groups according to surface treatments (group S: sandblasting; group A: acid etching; group SA: sandblasting + acid etching; group C: control). Surface roughness values of PEKK specimens were measured before and after surface treatment. After the prepared PEKK specimens were bonded to lithium-disilicate glass-ceramic specimens with resin cement, they were kept in distilled water at 37°C for 24 h. Half of the specimens in each surface treatment group were thermocycled. All test specimens underwent shear bond strength testing. Failure modes were assessed using light microscopy and SEM. Results: Statistical analysis demonstrated that surface treatments created significant roughness on the PEKK surfaces (p = 0.005). While group S showed the highest roughness values, group A showed the lowest. Of the thermocycled test groups, the sandblasting + acid etching group obtained the highest shear bond strengths. Among the non-thermocycled test groups, the sandblasting surface treatment group achieved the highest shear bond strengths. Conclusions: The application of surface treatments to enhance the bond strength of PEKK to ceramics has proven to be effective. [ABSTRACT FROM AUTHOR]

Purpose: To investigate the three-point flexural strength of a novel CAD/CAM fiber-reinforced composite (FRC) material following different aging conditions.Materials and Methods: The specimens were randomly assigned to one of five groups based on aging condition: (1) control (no treatment); (2) short-term water storage; (3) thermal degradation with autoclaving; (4) chemical degradation with hydrochloric acid; and (5) chemical degradation with citric acid (n = 10 per group). The specimens in the control group received no treatment. Following each treatment protocol, the three-point bending test was used to calculate the flexural strength. Data were statistically analyzed (α = .05), and scanning electron microscopy (SEM) analysis of the specimens was conducted.Results: No significant differences in flexural strength were observed among the groups (P = .199). In addition, no distinct morphologic differences were detected in the SEM images of the specimens.Conclusion: The flexural strength of this novel CAD/CAM FRC material was unaffected by different aging methods. [ABSTRACT FROM AUTHOR]

Copyright of European Oral Research is the property of Istanbul University, Faculty of Dentistry and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Purpose: To evaluate the light transmission characteristics of different types, shades, and thicknesses of novel CAD/CAM materials and their effect on the degree of conversion (DC) of a dual-curing resin cement. Materials and Methods: Square specimens (12 × 12 mm²) of three CAD/CAM materials - GC Cerasmart, Lava Ultimate, Vita Enamic - of different thicknesses (1.00, 1.50, and 2.00 mm, n = 5 per thickness) were irradiated with an LED unit. The amount of transmitted light was quantified. Thereafter, the DC% of the dual-curing resin cement (RelyX Ultimate) was recorded after 15 min using Fourier transform infrared spectroscopy. Statistical analysis was performed using two-way ANOVA followed by the Tukey's HSD post-hoc test at a significance level of p < 0.05. Regression analysis was performed to investigate the correlation between the DC and radiant energy, and the DC and thickness. Results: Although the type and shade of CAD/CAM material significantly affect transmitted light irradiation (p < 0.0001), degrees of conversion are similar when the CAD/CAM material or material shade were taken into consideration (p > 0.05). Conversely, material thickness significantly affected light transmission (p < 0.0001) and DC (p < 0.0001). Multiple effects of material, shade, and thickness did not significantly affect the evaluated parameters (p = 0.638 for light irradiation; p = 0.637 for DC). Linear regression analysis showed a correlation between delivered energy and DC% results of the Vita Enamic (R² = 0.4169, p < 0.0001). Conclusion: Reduced light transmission in 2-mm-thick specimens of all CAD/CAM materials indicates that proper curing of the cement beneath CAD/CAM materials should be ensured. [ABSTRACT FROM AUTHOR]

Copyright of Mersin Üniversitesi sağlık Bilimleri Dergisi is the property of Mersin University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Purpose: To investigate the effect of different light-curing units and adhesive systems on the bonding of leucite ceramic to dentin. Materials and Methods: Flat dentin surfaces were ground occlusally on human molars (n = 60). Hot-pressed ceramic blocks of IPS Empress (Ivoclar-Vivadent) were fabricated, air-particle abraded, and cleaned in distilled water. Following acid etching and silane treatment of ceramic, bonding procedures were performed. The teeth were divided into two groups according to the type of the adhesive system: (1) total-etch: etchant (Etch 37) and adhesive (One Step Plus); (2) self-etching: self-priming etchant (Tyrian SPE) and adhesiveOne Step Plus) (n = 30). Ceramic blocks were bonded to the dentin surfaces with dual-polymerizing resin luting cement (Duolink). For polymerization, the QTH (Blue Swan Digital, Dentanet) was used in soft-up and high-power mode, the LED (Elipar Freelight 2, 3M Espe) in exponential and standard mode, and the PAC (PlasmaStar, SP-2000, Monitex) in normal and ramp-curing mode (n = 5). Following storage in distilled water for 24 h, the samples were thermocycled for 6000 cycles. The bonded specimens were serially sectioned and trimmed to hourglass shapes with approximately 1.6 ± 0.16 mm2 cross-sectional areas, then tested with the microtensile tester at a rate of 1 mm/min. Fracture surfaces (were analyzed with SEM. The data were analyzed with three-way analysis of variance (ANOVA). Results: ANOVA revealed that adhesive systems (p < 0.001) and light-curing units (p = 0.015) had a significant effect on bond strength values. Bond strength means (± SD) in MPa were as follows: total-etch system: QTH/soft-up mode = 16.2 (5.4); QTH/high power mode = 15 (5.4); LED/standard mode = 12.1 (3.3); LED/exponential mode = 15 (5); PAC/normal mode = 19.3 (7); PAC/ramp-curing mode = 19.6 (7.4). Self-etching system: QTH/soft-up mode = 9.9 (2.1); QTH/high-power mode = 12.5 (4.3); LED/standard mode = 8.6 (2); LED/exponential mode = 13 (3.8); PAC/normal mode = 13.1 (3.9); PAC/ramp-curing mode = 8.9 (2.2). Conclusion: Results indicated that the conventional total-etch system provided more reliable bonding compared to the self-etching system. The PAC light-curing unit together with the total-etch adhesive system showed the highest mean µ-TBS values with either normal mode or ramp-curing mode. [ABSTRACT FROM AUTHOR]

Purpose: To compare the effect of different surface treatments on the bond strength of CAD/CAM fabricated resin-based and prefabricated fiber posts to root canal dentin. Methods: 160 single-rooted human teeth were selected and received endodontic treatment. The teeth were divided into four groups according to the post material used: (1) Prefabricated fiber-reinforced composite post (Snowpost), (2) CAD/CAM nanoceramic (Cerasmart), (3) CAD/CAM polymer infiltrated ceramic (Vita Enamic) and (4) CAD/CAM resin nanoceramic (Lava Ultimate). Then the posts were randomly assigned into four sub-groups according to the surface treatment method used: (1) Control (no treatment), (2) Laser (Er,Cr:YSGG laser device, Waterlase), (3) Hydrofluoric acid treatment [9.6% HF (Pulpdent) for 2 minutes], and (4) Sandblasting (50 pm A120 3). Following post space preparation, posts were cemented with dual-cure resin cement (Panavia SA cement plus). From each root, five 1 mm-thick slices were obtained. The micropush-out bond strength test was performed for each slice. Data were analyzed by using two-way ANOVA and Tukey HSD tests. The fracture modes were evaluated under a stereomicroscope. Representative specimens were analyzed with SEM following surface treatments. Results: Micropush-out bond strength of posts to dentin was significantly affected by the type of post material (P< 0.05), but not by the surface treatment (P= 0.397). [ABSTRACT FROM AUTHOR]

PURPOSE. The aim of this study was to compare the effect of different finishing and polishing techniques on water absorption, water solubility, and microhardness of ceramic or glass-polymer based computer-aided design and computer-aided manufacturing (CAD/CAM) materials following thermocycling. MATERIALS AND METHODS. 150 disc-shaped specimens were prepared from three different hybrid materials and divided into five subgroups according to the applied surface polishing techniques. All specimens were subjected up to #4000 grit SiC paper grinding. No additional polishing has been done to the control group (Group I). Other polishing procedures were as follows: Group II: two-stage diamond impregnated polishing discs; Group III: yellow colored rubber based silicone discs; Group IV: diamond polishing paste; and Group V: Aluminum oxide polishing discs. Subsequently, 5000-cycles of thermocycling were applied. The analyses were conducted after 24 hours, 7 days, and 30 days of water immersion. Water absorption and water solubility results were analyzed by two-way ANOVA and Tukey post-hoc tests. Besides, microhardness data were compared by Kruskal-Wallis and Mann- Whitney U tests (P<.05). RESULTS. Surface polishing procedures had significant effects on water absorption and solubility and surface microhardness of resin ceramics (P<.05). Group IV exhibited the lowest water absorption and the highest microhardness values (P<.05). Immersion periods had no effect on the microhardness of hybrid ceramic materials (P>.05). CONCLUSION. Surface finishing and polishing procedures might negatively affect physical properties of hybrid ceramic materials. Nevertheless, immersion periods do not affect the microhardness of the materials. Final polishing by using diamond polishing paste can be recommended for all CAD/CAM materials. [ABSTRACT FROM AUTHOR]

Copyright of Acta Odontologica Turcica is the property of Acta Odontologica Turcica and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The aim of this study was to evaluate the effect of cyclic loading on the bond strength of fiber posts and short fiber-reinforced composite (FRC) to root canal. One hundred single-rooted teeth were divided into two groups according to the material used for luting fiber posts: (1) Resin-core material (Gradia Core, GC Corp.) and (2) Short FRC (EverX Posterior, GC Corp.). Then the specimens were randomly assigned into three sub-groups according to the post material and the groups are indicated as follows: (1) Short FRC (EverX Posterior) used instead of post and core, (2) Fiber post (GC post, GC Corp.) cemented with resin-core (Gradia Core), (3) Fiber post (GC post, GC Corp.) cemented with short FRC (EverX Posterior), (4) Experimental fiber post cemented with resin-core (Gradia Core, GC Corp), (5) Experimental fiber post cemented with short FRC (EverX Posterior). Then the specimens were subdivided into a further two groups in accordance with the storage condition (cyclic loading and 24 h water storage-control group) (n = 10/per group). The micropush-out bond strength between root dentin and posts was measured. Data were analyzed using three-way ANOVA and Tukey HSD tests (α = 0.05). Micropush-out bond strength of the posts to dentin was significantly affected by the type of post material (p < 0.05). However, the load cycling and the resin-based luting agent used had no effect on bond strength values (p = 0.706 andp = 0.346, respectively). [ABSTRACT FROM AUTHOR]