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1.
Effect of air-polishing on surface roughness of composite dental restorative material - comparison of three different air-polishing powders.
Janiszewska-Olszowska, J, Drozdzik, A, Tandecka, K, Grocholewicz, K
BMC oral health. 2020;(1):30
Abstract
BACKGROUND Increased composite roughness enhances bacterial adhesion and discoloration, thus increasing the risk of gingival inflammation and secondary caries. Concerns about detrimental effects of sodium bicarbonate on surface roughness influenced the development of less abrasive powders: a glycine-based powder and an erythritol-based powder, additionally - sodium bicarbonate-based powder of reduced grain size. However, there is limited evidence on effects of these materials on the surface of dental fillings. The aim of the present study was to compare the effects of three air-polishing powders (of a reduced abrasiveness) on surface roughness of microhybrid restorative composite material. MATERIAL AND METHODS Microhybrid light-cure resin composite samples were placed on 64 plaster cubes and light-cured through polyester strips. Surface roughness was measured using laser confocal microscope (magnification 2160x). The specimens were randomly divided into three groups (n = 20, 20 and 24) and air-polished with: sodium bicarbonate (40 μm), glycine (25 μm) and erythritol (14 μm), respectively. Then surface roughness was remeasured, keeping the same field of observation. Specialized 3D analysis software was used for data processing. Parameters according to ISO 25178: Sa, Sq, Sku, Sp, Sv, Sz, Ssk were used to describe surface roughness. RESULTS Sa, Sq, Sp, Sv, Sz increased significantly following air polishing. Ssk was significantly higher, whereas Sku was significantly lower in sodium bicarbonate and erythritol groups than before air polishing. Comparison between the three powders revealed that Sa was significantly higher in sodium bicarbonate group than in glycine group. Sku was significantly higher in glycine and erythritol groups than in sodium bicarbonate group. CONCLUSIONS Sodium bicarbonate has a stronger detrimental effect on composite surface than glycine or erythritol. No advantage of erythritol comparing to glycine could be found.
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2.
Safety and effectiveness of early loaded maxillary titanium implants with a novel nanostructured calcium-incorporated surface (Xpeed): 3-year results from a pilot multicenter randomised controlled trial.
Felice, P, Grusovin, MG, Barausse, C, Grandi, G, Esposito, M
European journal of oral implantology. 2015;(3):245-54
Abstract
PURPOSE To evaluate clinical safety and effectiveness of a novel calcium-incorporated titanium implant surface (Xpeed, MegaGen Implant Co., Gyeongbuk, South Korea). MATERIALS AND METHODS Sixty patients were randomised to receive one to six implants in the maxilla with either calcium-incorporated (Xpeed) or control resorbable blasted media (RBM) surfaces, according to a parallel group design at two centres. Implants were submerged and exposed at three different endpoints in equal groups of 20 patients, each at 12, 10 and 8 weeks, respectively. Within 2 weeks, implants were functionally loaded with provisional or definitive prostheses. Outcome measures were prosthesis failures, implant failures, any complications and peri-implant marginal bone level changes. RESULTS Thirty patients received 45 calcium-incorporated implants and 30 patients received 42 control titanium implants. Three years after loading four patients dropped-out from the Xpeed group and one from the RBM group. No prosthesis or implant failures occurred. There were no statistically significant differences between the groups for complications (P = 0.91; difference in proportions = 0.79 %; 95% CI -0.71 to 2.29) and mean marginal bone level changes (P = 0.88; mean difference = -0.02 mm; 95% CI -0.26 to 0.22). CONCLUSIONS Both implant surfaces provided good clinical results and no significant difference was found when comparing titanium implants with a nanostructured calcium-incorporated surface versus implants with RBM surfaces.
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3.
Shear bond strength of veneering porcelain to zirconia after argon plasma treatment.
Canullo, L, Micarelli, C, Bettazzoni, L, Magnelli, A, Baldissara, P
The International journal of prosthodontics. 2014;(2):137-9
Abstract
PURPOSE The aim of this study was to investigate if argon plasma cleaning increases the shear bond strength between zirconia and veneering ceramic surfaces. MATERIALS AND METHODS Ninety tablets of densely sintered yttriastabilized tetragonal zirconia polycrystal were divided into three groups according to cleaning treatment (steam cleaning or plasma of Argon for 375 or 750 seconds). Groups were divided into two subgroups according to the application of a ceramic liner (A = liner, B = no liner). RESULTS Within subgroup A, argon plasma cleaning significantly decreased shear bond strength. In subgroup B, the plasma treatment increased the shear bond strength, but the differences were not statistically significant. Subgroup A demonstrated lower shear bond strength compared to subgroup B. CONCLUSIONS Argon plasma cleaning was suggested to improve the bond between ceramic and zirconia surfaces; however, when plasma cleaning was followed by a glassy liner application, the veneering ceramic/zirconia bond was significantly reduced.
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4.
Effect on push-out bond strength of glass-fiber posts functionalized with polydopamine using different adhesives.
Chen, Q, Cai, Q, Li, Y, Wei, XY, Huang, Z, Wang, XZ
The journal of adhesive dentistry. 2014;(2):177-84
Abstract
PURPOSE To evaluate the push-out bond strengths of prefabricated glass-fiber posts (Beijing Oya Biomaterials) with polydopamine functionalized to root dentin using two different resin cements (Paracore and RelyX Unicem) in different root regions (cervical, middle, and apical). MATERIALS AND METHODS Forty extracted human, single-rooted teeth were endodontically treated and a 9-mm post space was prepared in each tooth with post drills provided by the manufacturer. Specimens were then randomly assigned into four groups (n = 10 per group), depending on the adhesive system and post surface treatment used: group IA (Paracore + polydopamine); group IB (Paracore + control); group IIA (RelyX Unicem + polydopamine); group IIB (RelyX Unicem + control). Following post cementation, the specimens were stored in distilled water at 37°C for 7 days. The push-out test was performed using a universal testing machine (0.5 mm/ min), and the failure modes were examined with a stereomicroscope. Data were statistically analyzed using twoway ANOVA (p = 0.05). RESULTS Bond strengths (mean ± SD) were: 7.909 ± 3.166 MPa (group IA), 4.675 ± 2.170 MPa (group IB), 8.186 ± 2.766 MPa (group IIA), 4.723 ± 2.084 MPa (group IIB). The bond strength of polydopamine groups was significantly higher than one of the control groups (p < 0.0001). No significant difference was found in the micro push-out bond strengths between the two resin cement groups or the root regions (p > 0.05). Stereomicroscopic analysis showed a higher percentage of adhesive than cohesive failures in all groups. CONCLUSION Surface polydopamine functionalization was confirmed to be a reliable method for improving the bond strength of resin luting agents to fiber posts. The bond strength of Paracore to fiber posts was not significantly different from that of RelyX Unicem, and considering its convenient application, Paracore can be recommended.
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5.
Effect of surface treatments of zirconia ceramics on the bond strength to resin cement.
Cheung, GC, Botelho, MG, Matinlinna, JP
The journal of adhesive dentistry. 2014;(1):49-56
Abstract
PURPOSE The purpose of this in vitro study was to evaluate the bond strength of a resin luting cement to zirconia surfaces that had received two novel surface pretreatment methods: etching of a pre-fired overglaze or paste liner on the zirconia substrate. MATERIALS AND METHODS Fully sintered zirconia disks were assigned to 6 groups according to the surface pretreatment: firing of 2 layers of paste liner which was then etched with hydrofluoric acid and treated with silane (Liner group); firing of 2 layers of overglaze which were then etched with hydrofluoric acid and treated with silane (glaze group); Rocatec treatment and silane application (Rocatec group); Rocatec treatment followed by ultrasonic cleaning and silanization (ultrasonic-Rocatec group); sandblasted with alumina (alumina group); as-sintered with no pretreatment (control group). Twenty composite resin cylinders were bonded to each group with Panavia F 2.0. Each group was further divided into 2 subgroups (n = 10) for 2 different storage conditions: 24 h water storage or 3 weeks water storage plus 6000 thermocycles between 5°C and 55°C. The shear bond strength was then determined. Statistical analyses with two-way ANOVA were conducted; the level of significance was set at p < 0.05. RESULTS At 24 h, the shear bond strength values of all groups except the control showed no statistically significant difference. After artificial aging, the mean bond strength of all groups dropped, but the decrease in the glaze group was not statistically significant. The glaze group showed the highest shear bond strength. However, that was not statistically different from the liner or the Rocatec group without ultrasonic cleaning (p < 0.05). All the control specimens debonded spontaneously after aging. Ultrasonic cleaning after Rocatec treatment caused a reduction in shear bond strength, but the difference was not statistically significant. CONCLUSION Both the fired paste liner and overglazed ceramic treated zirconia surfaces provided a strong and durable bond to resin cement under the conditions tested.
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6.
Effect of postoperative peroxide bleaching on the stability of composite to enamel and dentin bonds.
Dudek, M, Roubickova, A, Comba, L, Housova, D, Bradna, P
Operative dentistry. 2013;(4):394-407
Abstract
This study investigated the effect of peroxide bleaching gel on the durability of the adhesive bond between composite material, enamel, and dentin created with the etch-and-rinse adhesive Gluma Comfort Bond (GLU) and with the self-etch adhesives Clearfil SE Bond (CLE), Adper Prompt (ADP), and iBond (IBO). The adhesives were applied to flattened enamel and dentin of extracted human molars and built up with a microhybrid composite (Charisma). After 25 eight-hour cycles of bleaching with a 20% carbamide peroxide bleaching gel (Opalescence PF 20), the shear bond strength was measured and compared with one-day and two-month control specimens stored in water. The data were analyzed using nonparametric Mann-Whitney and Kruskal-Wallis statistics (p<0.05). Detailed fractographic analysis was performed using scanning electron microscopy. The bleaching gel significantly decreased the bond strength on both enamel and dentin for the simplified single-step self-etch adhesives ADP and IBO and markedly affected a fracture pattern of ADP specimens at the periphery of their bonded area. The results of our study indicate that the durability of adhesive restorations can be detrimentally influenced by carbamide peroxide bleaching and that different adhesives show varying sensitivity levels to the bleaching gel.
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7.
Push-out bond strengths of different dental cements used to cement glass fiber posts.
Pereira, JR, Lins do Valle, A, Ghizoni, JS, Lorenzoni, FC, Ramos, MB, Dos Reis Só, MV
The Journal of prosthetic dentistry. 2013;(2):134-40
Abstract
STATEMENT OF PROBLEM Since the introduction of glass fiber posts, irreversible vertical root fractures have become a rare occurrence; however, adhesive failure has become the primary failure mode. PURPOSE The purpose of this study was to evaluate the push-out bond strength of glass fiber posts cemented with different luting agents on 3 segments of the root. MATERIAL AND METHODS Eighty human maxillary canines with similar root lengths were randomly divided into 8 groups (n=10) according to the cement assessed (Rely X luting, Luting and Lining, Ketac Cem, Rely X ARC, Biscem, Duo-link, Rely X U100, and Variolink II). After standardized post space preparation, the root dentin was pretreated for dual-polymerizing resin cements and untreated for the other cements. The mixed luting cement paste was inserted into post spaces with a spiral file and applied to the post surface that was seated into the canal. After 7 days, the teeth were sectioned perpendicular to their long axis into 1-mm-thick sections. The push-out test was performed at a speed of 0.5 mm/min until extrusion of the post occurred. The results were evaluated by 2-way ANOVA and the all pairwise multiple comparison procedures (Tukey test) (α=.05). RESULTS ANOVA showed that the type of interaction between cement and root location significantly influenced the push-out strength (P<.05). The highest push-out strength results with root location were obtained with Luting and Lining (S3) (19.5 ±4.9 MPa), Ketac Cem (S2) (18.6 ±5.5 MPa), and Luting and Lining (S1) (18.0 ±7.6 MPa). The lowest mean values were recorded with Variolink II (S1) (4.6 ±4.0 MPa), Variolink II (S2) (1.6 ±1.5 MPa), and Rely X ARC (S3) (0.9 ±1.1 MPa). CONCLUSIONS Self-adhesive cements and glass ionomer cements showed significantly higher values compared to dual-polymerizing resin cements. In all root segments, dual-polymerizing resin cements provided significantly lower bond strength. Significant differences among root segments were found only for Duo-link cement.
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8.
Effect of surface conditioning modalities on the repair bond strength of resin composite to the zirconia core / veneering ceramic complex.
Ozcan, M, Valandro, LF, Pereira, SM, Amaral, R, Bottino, MA, Pekkan, G
The journal of adhesive dentistry. 2013;(3):207-10
Abstract
PURPOSE This study evaluated the effect of different surface conditioning protocols on the repair strength of resin composite to the zirconia core / veneering ceramic complex, simulating the clinical chipping phenomenon. MATERIALS AND METHODS Forty disk-shaped zirconia core (Lava Zirconia, 3M ESPE) (diameter: 3 mm) specimens were veneered circumferentially with a feldspathic veneering ceramic (VM7, Vita Zahnfabrik) (thickness: 2 mm) using a split metal mold. They were then embedded in autopolymerizing acrylic with the bonding surfaces exposed. Specimens were randomly assigned to one of the following surface conditioning protocols (n = 10 per group): group 1, veneer: 4% hydrofluoric acid (HF) (Porcelain Etch) + core: aluminum trioxide (50-µm Al2O3) + core + veneer: silane (ESPE-Sil); group 2: core: Al2O3 (50 µm) + veneer: HF + core + veneer: silane; group 3: veneer: HF + core: 30 µm aluminum trioxide particles coated with silica (30 µm SiO2) + core + veneer: silane; group 4: core: 30 µm SiO2 + veneer: HF + core + veneer: silane. Core and veneer ceramic were conditioned individually but no attempt was made to avoid cross contamination of conditioning, simulating the clinical intraoral repair situation. Adhesive resin (VisioBond) was applied to both the core and the veneer ceramic, and resin composite (Quadrant Posterior) was bonded onto both substrates using polyethylene molds and photopolymerized. After thermocycling (6000 cycles, 5°C-55°C), the specimens were subjected to shear bond testing using a universal testing machine (1 mm/min). Failure modes were identified using an optical microscope, and scanning electron microscope images were obtained. Bond strength data (MPa) were analyzed statistically using the non-parametric Kruskal-Wallis test followed by the Wilcoxon rank-sum test and the Bonferroni Holm correction (α = 0.05). RESULTS Group 3 demonstrated significantly higher values (MPa) (8.6 ± 2.7) than those of the other groups (3.2 ± 3.1, 3.2 ± 3, and 3.1 ± 3.5 for groups 1, 2, and 4, respectively) (p < 0.001). All groups showed exclusively adhesive failure between the repair resin and the core zirconia. The incidence of cohesive failure in the ceramic was highest in group 3 (8 out of 10) compared to the other groups (0/10, 2/10, and 2/10, in groups 1, 2, and 4, respectively). SEM images showed that air abrasion on the zirconia core only also impinged on the veneering ceramic where the etching pattern was affected. CONCLUSION Etching the veneer ceramic with HF gel and silica coating of the zirconia core followed by silanization of both substrates could be advised for the repair of the zirconia core / veneering ceramic complex.
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Flexural properties of resin composites: influence of specimen dimensions and storage conditions.
Calheiros, FC, Pfeifer, CS, Brandão, LL, Agra, CM, Ballester, RY
Dental materials journal. 2013;(2):228-32
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Abstract
This study evaluated the influence of specimen dimensions and storage medium and temperature on the flexural properties of one dental resin composite. The material utilized throughout the study was Clearfil AP-X. Eighty specimens were built with dimensions of either 10×2×2 mm or 25×2×2 mm, stored dry or in distilled water, at 25 or 37ºC, for 24 h. Flexural strength and modulus were tested in three-point bending. Results were evaluated with three-way ANOVA and Tukey's test (α=0.05). Statistical significance was observed for all three factors: temperature (37ºC=190.8 MPa, 25ºC=165.3 MPa; p<0.01), storage medium (water=167.7 MPa, Dry=188.4 MPa; p<0.01) and specimen dimensions (10×2×2 mm=197.9 MPa, 25×2×2 mm=158.2 MPa; p<0.01). None of the interactions were significant. Within the limitations of this study, it can be concluded that factors such as specimen dimensions, storage medium and temperature significantly affect flexural strength results, which invalidates comparisons of results from studies that use different methodologies.
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Effect of artificial aging and surface treatment on bond strengths to dental zirconia.
Perdigão, J, Fernandes, SD, Pinto, AM, Oliveira, FA
Operative dentistry. 2013;(2):168-76
Abstract
The objective of this project was to study the influence of artificial aging and surface treatment on the microtensile bond strengths (μTBS) between zirconia and a phosphate monomer-based self-adhesive cement. Thirty zirconia disks (IPS e.max ZirCAD, Ivoclar Vivadent) were randomly assigned to two aging regimens: AR, used as received, which served as a control, and AG, artificial aging to simulate low-temperature degradation. Subsequently, the disks of each aging regimen were assigned to three surface treatments: NT, no surface treatment; CO, surface silicatization with CoJet sand (3M ESPE); and ZP, zirconia surface treated with Z-Prime Plus (Bisco Inc). Thirty discs were made of Filtek Z250 (3M ESPE) composite resin and luted to the zirconia discs using RelyX Unicem (3M ESPE). The specimens were sectioned with a diamond blade in X and Y directions to obtain bonded beams with a cross-section of 1.0 ± 0.2 mm. The beams were tested in tensile mode in a universal testing machine at a speed of 0.5 mm/min to measure μTBS. Selected beams were selected for fractographic analysis under the SEM. Statistical analysis was carried out with two-way analysis of variance and Dunnett T3 post hoc test at a significance level of 95%. The mean μTBS for the three AR subgroups (AR-NT, AR-CO, and AR-ZP) were significantly higher than those of the corresponding AG groups (p<0.0001). Both AR-CO and AR-ZP resulted in statistically significant higher mean bond strengths than the group AR-NT (p<0.006 and p<0.0001, respectively). Both AG-CO and AG-ZP resulted in statistically significant higher mean bond strengths than the group AG-NT (both at p<0.0001). Overall, AG decreased mean μTBS. Under the SEM, mixed failures showed residual cement attached to the zirconia side of the beams. CO resulted in a characteristic roughness of the zirconia surface. AR-ZP was the only group for which the amount of residual cement occupied at least 50% of the interface in mixed failures.