Bonding polycarbonate brackets to ceramic: effects of substrate treatment on bond strength.

This study evaluated the effects of 5 different surface conditioning methods on the bond strength of polycarbonate brackets bonded to ceramic surfaces with resin based cement. Six disc-shaped ceramic specimens (feldspathic porcelain) with glazed surfaces were used for each group. The specimens were randomly assigned to 1 of the following treatment conditions of the ceramic surface: (1) orthophosphoric acid + primer + bonding agent, (2) hydrofluoric acid gel + primer + bonding agent, (3) tribochemical silica coating (silicon dioxide, 30microm) + silane, (4) airborne particle abrasion (aluminum trioxide, 30microm) + silane, and (5) airborne particle abrasion (aluminum trioxide, 30microm) + silane + bonding agent. Brackets were bonded to the conditioned ceramic specimens with a light-polymerized resin composite. All specimens were stored in water for 1 week at 37 degrees C and then thermocycled (1000 cycles, 5 degrees C to 55 degrees C, 30 seconds). The shear bond strength values were measured on a universal testing machine at a crosshead speed of 1 mm/min. Brackets treated with silica coating with silanization had significantly greater bond strength values (13.6 MPa, P =.01) than brackets treated with orthophosphoric acid (8.5 MPa). There was no significant difference (P =.97) between the bond strengths obtained after airborne abrasion with aluminium trioxide particles followed by silanization (12 MPa) and hydrofluoric acid application (11.2 MPa) (ANOVA and Tukey test). Although brackets conditioned with orthophosphoric acid exhibited only adhesive failures of the luting cement from the ceramic surface, other conditioning methods showed mixed types of failures. Airborne particle abrasion with aluminium trioxide or silica coating followed by silanization gave the most favorable bond strengths. The types of failures observed after debonding indicated that the critical parameter was the strength of the adhesive joint of the luting cement to both the bracket and the ceramic.     

Effects of silica coating and silane surface conditioning on the bond strength of rebonded metal and ceramic brackets

Objective

The aim of this study was to evaluate the effects of tribochemical silica coating and silane surface conditioning on the bond strength of rebonded metal and ceramic brackets.

Material and Methods

Twenty debonded metal and 20 debonded ceramic brackets were randomly assigned to receive one of the following surface treatments (n=10 for each group): (1) sandblasting (control); (2) tribochemical silica coating combined with silane. Brackets were rebonded to the enamel surface on the labial and lingual sides of premolars with a light-polymerized resin composite. All specimens were stored in distilled water for 1 week and then thermocycled (5,000 cycles) between 5-55°C. Shear bond strength values were measured using a universal testing machine. Student''s t-test was used to compare the data (α=0.05). Failure mode was assessed using a stereomicroscope, and the treated and non-treated bracket surfaces were observed by scanning electron microscopy.

Results

Rebonded ceramic brackets treated with silica coating followed by silanization had significantly greater bond strength values (17.7±4.4 MPa) than the sandblasting group (2.4±0.8 MPa, P<0.001). No significant difference was observed between the rebonded metal brackets treated with silica coating with silanization (15±3.9 MPa) and the sandblasted brackets (13.6±3.9 MPa). Treated rebonded ceramic specimens primarily exhibited cohesive failure in resin and adhesive failure at the enamel-adhesive interface.

Conclusions

In comparison to sandblasting, silica coating with aluminum trioxide particles followed by silanization resulted in higher bond strengths of rebonded ceramic brackets.     

The effect of silica coating on the resin bond to the intaglio surface of Procera AllCeram restorations.

OBJECTIVES: This study investigated the influence of a silica-coating method on the resin bond of two different resin composite cements to the intaglio surface of Procera AllCeram densely sintered, high-purity, alumina ceramic restorations after long-term storage and thermocycling. METHOD AND MATERIALS: Densely sintered alumina ceramic specimens were fabricated with the intaglio surface of the Procera AlICeram coping and randomly divided into five adhesive groups (100 total specimens). Resin composite cylinders were bonded either to the untreated or to the tribochemical silica/silane-coated ceramic surface with either a conventional Bis-GMA resin cement or a resin composite containing an adhesive phosphate monomer (Panavia 21) in combination with their corresponding bonding/silane coupling agents. Panavia was also used without silanization to the untreated ceramic surface (control). Subgroups of 10 specimens were stored in distilled water for either 3 (baseline) or 180 days prior to shear bond strength testing. The 180-day samples were subjected to repeated thermocycling for a total of 12,000 cycles. Data were analyzed with one-way analysis of variance and Tukey's multiple comparison. RESULTS: Silica coating significantly increased overall bond strength to Procera AllCeram. RelyX ARC and silica coating revealed the highest bond strength at baseline. Long-term storage and thermocycling significantly decreased overall bond strength. Two groups revealed the significantly highest bond strength values after artificial aging: Panavia 21 with its silane/bonding agent to the original ceramic surface and Panavia 21 to the silica-coated ceramic surface. CONCLUSION: The use of a resin composite containing an adhesive phosphate monomer either in combination with a silane coupling/bonding agent or after tribochemical silica/silane coating revealed the highest long-term shear bond strength to the intaglio surface of Procera AllCeram restorations.     

Effects of surface-conditioning methods on shear bond strength of brackets bonded to different all-ceramic materials

The aims of this study were to investigate the effects of two surface-conditioning methods on the shear bond strength (SBS) of metal brackets bonded to three different all-ceramic materials, and to evaluate the mode of failure after debonding. Twenty feldspathic, 20 fluoro-apatite, and 20 leucite-reinforced ceramic specimens were examined following two surface-conditioning methods: air-particle abrasion (APA) with 25 μm Al(2)O(3) and silica coating with 30 μm Al(2)O(3) particles modified by silica. After silane application, metal brackets were bonded with light cure composite and then stored in distilled water for 1 week and thermocycled (×1000 at 5-55°C for 30 seconds). The SBS of the brackets was measured on a universal testing machine. The ceramic surfaces were examined with a stereomicroscope to determine the amount of composite resin remaining using the adhesive remnant index. Two-way analysis of variance, Tukey's multiple comparison test, and Weibull analysis were used for evaluation of SBS. The lowest SBS was with APA for the fluoro-apatite ceramic (11.82 MPa), which was not significantly different from APA for the feldspathic ceramic (13.58 MPa). The SBS for the fluoro-apatite ceramic was significantly lower than that of leucite-reinforced ceramic with APA (14.82 MPa). The highest SBS value was obtained with silica coating of the leucite-reinforced ceramic (24.17 MPa), but this was not significantly different from the SBS for feldspathic and fluoro-apatite ceramic (23.51 and 22.18 MPa, respectively). The SBS values with silica coating showed significant differences from those of APA. For all samples, the adhesive failures were between the ceramic and composite resin. No ceramic fractures or cracks were observed. Chairside tribochemical silica coating significantly increased the mean bond strength values.     

Influence of different surface treatments on the short-term bond strength and durability between a zirconia post and a composite resin core material

STATEMENT OF PROBLEM: Reliable bonding between zirconia posts and composite resin core materials is difficult to achieve because of the smooth surface texture and lack of silica content of zirconia posts. PURPOSE: The purpose of this study was to evaluate the effect of different surface treatments on the short-term bond strength and durability between a zirconia post and a composite resin core material. MATERIAL AND METHODS: Eighty zirconia posts were divided into 4 groups (n=20). Specimens received 1 of 4 different surface treatments: group AIRB, airborne-particle abrasion; group TSC-SIL, tribochemical silica coating (CoJet system) and silanization (ESPE Sil); group AIRB-BSIL, airborne-particle abrasion and MDP-containing primer (Clearfil SE Bond Primer)/silane coupling agent (Clearfil Porcelain Bond Activator) mixture application; and group TSC-BSIL, tribochemical silica coating and MDP-containing primer/silane coupling agent mixture application. Average surface roughness (Ra) of zirconia posts produced by airborne-particle abrasion or silica coating was measured using an optical profilometer. Composite resin core foundations (Build-it FR) were formed using transparent acrylic resin tubes (12mm in length and 7mm in diameter). Each group was further divided into 2 subgroups of 10 specimens and stored in distilled water at 37 degrees C, either for 24 hours or for 150 days with 37,500 thermal cycles between 5 degrees C and 55 degrees C, with a dwell time of 30 seconds. Following water storage, the specimens were sectioned perpendicular to the bonded interface into 2-mm-thick post-and-core specimens under water cooling. Push-out tests were performed with a universal testing machine at a crosshead speed of 0.5mm/min. Debonded post surfaces were examined with SEM. Data were analyzed with 1- and 2-way ANOVA and Tukey multiple comparison tests (alpha=0.05). RESULTS: No significant differences were detected between the Ra values of airborne-particle-abraded and silica-coated specimens (P=.781). The short-term mean bond strengths for group TSC-BSIL (27.1 +/- 3.2 MPa) and TSC-SIL (25.2 +/- 2.4 MPa) were statistically higher (P<.001) than AIRB-BSIL (23.3 +/- 2.2 MPa). The relatively high bond strengths for groups TSC-BSIL and TSC-SIL decreased significantly after 150 days of water storage to 13.5 +/- 1.6 and 11.8 +/- 1.2 MPa, respectively (P<.001). Durable bonding was obtained only in group AIRB-BSIL (21.8 +/- 2.7 MPa), which was also the only group demonstrating predominantly cohesive failures in the core material after long-term water storage. CONCLUSIONS: Data suggest that the short-term high bond strength obtained with a silane coupling agent or MPD-containing primer/silane coupling agent mixture to silica-coated zirconia posts was decreased with water storage and thermal cycling, whereas a durable bond could be obtained when an MPD-containing primer/silane coupling agent mixture was applied to the airborne-particle-abraded post surface.     

Effect of zirconium-oxide ceramic surface treatments on the bond strength to adhesive resin

STATEMENT OF PROBLEM: Surface treatment methods used for resin bonding to conventional silica-based dental ceramics are not reliable for zirconium-oxide ceramics. PURPOSE: The aim of this study was to compare the effects of airborne-particle abrasion, silanization, tribochemical silica coating, and a combination of bonding/silane coupling agent surface treatment methods on the bond strength of zirconium-oxide ceramic to a resin luting agent. MATERIAL AND METHODS: Sixty square-shaped (5 x 5 x 1.5 mm) zirconium-oxide ceramic (Cercon) specimens and composite resin (Z-250) cylinders (3 x 3 mm) were prepared. The ceramic surfaces were airborne-particle abraded with 125-microm aluminum-oxide (Al(2)O(3)) particles and then divided into 6 groups (n = 10) that were subsequently treated as follows: Group C, no treatment (control); Group SIL, silanized with a silane coupling agent (Clearfil Porcelain Bond Activator); Group BSIL, application of the adhesive 10-methacryloyloxydecyl dihydrogen phosphate monomer (MDP)-containing bonding/silane coupling agent mixture (Clearfil Liner Bond 2V/ Porcelain Bond Activator); Group SC, silica coating using 30-microm Al(2)O(3) particles modified by silica (CoJet System); Group SCSIL, silica coating and silanization (CoJet System); and Group SCBSIL, silica coating and application of an MDP-containing bonding/silane coupling agent mixture (Clearfil Liner Bond 2V/Porcelain Bond Activator). The composite resin cylinders were bonded to the treated ceramic surfaces using an adhesive phosphate monomer-containing resin luting agent (Panavia F). After the specimens were stored in distilled water at 37 degrees C for 24 hours, their shear bonding strength was tested using a universal testing machine at a crosshead speed of 0.5 mm/min. Debonded specimen surfaces were examined with a stereomicroscope to assess the mode of failure, and the treated surfaces were observed by scanning electron microscopy. Bond strength data were analyzed using 1-way analysis of variance and the Duncan test (alpha = .05). RESULTS: The bond strengths (mean +/- SD; MPa) in the groups were as follows: Group C, 15.7 +/- 2.9; Group SIL, 16.5 +/- 3.4; Group BSIL, 18.8 +/- 2.8; Group SC, 21.6 +/- 3.6; Group SCSIL, 21.9 +/- 3.9; and Group SCBSIL, 22.9 +/- 3.1. The bond strength was significantly higher in Group SCBSIL than in Groups C, SIL, and BSIL (P<.001), but did not differ significantly from those in Groups SC and SCSIL. Failure modes were primarily adhesive at the interface between zirconium and the resin luting agent in Groups C and SIL, and primarily mixed and cohesive in Groups SC, SCSIL, and SCBSIL. CONCLUSION: Tribochemical silica coating (CoJet System) and the application of an MDP-containing bonding/silane coupling agent mixture increased the shear bond strength between zirconium-oxide ceramic and resin luting agent (Panavia F).     

Effect of silica coating and silanization on flexural and composite-resin bond strengths of zirconia posts: An in vitro study

STATEMENT OF PROBLEM: The bond strength of composite resin cores to the smooth surface of prefabricated zirconia-based ceramic posts is problematic because it might not be sufficient to ensure stability of the post-and-core system. It is also not clear whether any alteration of the post surface to provide additional mechanical or chemical retention would compromise flexural strength of the posts. PURPOSE: This study tested the effect of a tribochemical treatment on the bond strength (BS) between zirconia-based ceramic posts and composite resin and on the flexural strength (FS) of the posts. MATERIAL AND METHODS: For the BS test, 2 groups of specimens (n = 10) were prepared as follows: In the experimental (E) group, zirconia-based ceramic posts (Cosmopost), 21 mm long and 1.7 mm in diameter, were treated with a tribochemical silica coating and silanization system (Rocatec). For the control (C) group, zirconia-based ceramic posts were used as supplied by the manufacturer. For the 2 groups, posts were centered and vertically positioned in a metal mold, and composite resin (Tetric Ceram) was polymerized around the posts to form rings (6 mm diameter x 4 mm height). All specimens were positioned in a universal testing machine, and a load was applied axially on the protruding heads of posts in a shear push-out mode test until bond failure (MPa). Fracture mode was assessed as cohesive, cohesive/adhesive, or adhesive. Following this, the FS of the posts was measured in MPa using a 3-point bending test. Data were recorded and statistically analyzed using the Student t test for both tests (alpha = .01). RESULTS: Mean fracture load values +/- SDs for the BS test were 28.1 +/- 2.3 MPa and 8.9 +/- 3.97 MPa for the E and C groups, respectively. The mean FS values were 1544.9 +/- 214.1 MPa and 844.8 +/- 50.8 MPa for the E and C groups, respectively. The tribochemically treated posts exhibited significantly higher values for both bond strength to composite resin and resistance to fracture when compared to posts in the control group (P < .001). Fracture analysis showed 100% cohesive/adhesive fractures for group E specimens and 100% adhesive fractures for group C specimens. CONCLUSIONS: The use of a tribochemical silica coating process and silanization on zirconia-based ceramic posts increased both the bond strength to composite resin as well as the fracture strength of posts.     

Resin bond strength to densely sintered alumina ceramic

PURPOSE: The aim of this in vitro study was to investigate the resin bond strength and durability of adhesive bonding systems to densely sintered, pure aluminum oxide ceramic. MATERIALS AND METHODS: Acrylic glass tubes filled with composite resin were bonded to industrially manufactured alumina ceramic disks with an ultrasonically machined surface. Groups of 20 samples were bonded in an alignment apparatus using five different bonding methods. Subgroups of 10 bonded samples were tested for tensile strength following storage in distilled water at 37 degrees C for either 3 or 150 days. In addition, the 150-day samples were thermocycled 37,500 times. The statistical analyses were made by the Kruskal-Wallis test, followed by multiple pairwise comparison of the groups using the Mann-Whitney test. RESULTS: The mean bond strength of a bis-GMA composite resin to sandblasted alumina ceramic was relatively high after 3 days, at 20 MPa. Additional silanization or tribochemical silica coating and silanization did not enhance the bond strength (18 to 20 MPa) and failed spontaneously over long-term storage. However, using a composite resin containing a special adhesive phosphate monomer, a statistically significantly higher and durable bond strength to the sandblasted alumina ceramic surface was achieved after 3 days (50 MPa) and after 150 days of storage (46 MPa). CONCLUSION: A durable bond strength to pure alumina ceramic was achieved only by using a composite resin containing an adhesive phosphate monomer after sandblasting the ceramic surface.     

Effect of surface conditioning methods on the bond strength of luting cement to ceramics

OBJECTIVES: This study evaluated the effect of three different surface conditioning methods on the bond strength of a Bis-GMA based luting cement to six commercial dental ceramics. METHODS: Six disc shaped ceramic specimens (glass ceramics, glass infiltrated alumina, glass infiltrated zirconium dioxide reinforced alumina) were used for each test group yielding a total number of 216 specimens. The specimens in each group were randomly assigned to one of the each following treatment conditions: (1) hydrofluoric acid etching, (2) airborne particle abrasion, (3) tribochemical silica coating. The resin composite luting cement was bonded to the conditioned and silanized ceramics using polyethylene molds. All specimens were tested at dry and thermocycled (6.000, 5-55 degrees C, 30 s) conditions. The shear bond strength of luting cement to ceramics was measured in a universal testing machine (1 mm/min). RESULTS: In dry conditions, acid etched glass ceramics exhibited significantly higher results (26.4-29.4 MPa) than those of glass infiltrated alumina ceramics (5.3-18.1 MPa) or zirconium dioxide (8.1 MPa) (ANOVA, P<0.001). Silica coating with silanization increased the bond strength significantly for high-alumina ceramics (8.5-21.8 MPa) and glass infiltrated zirconium dioxide ceramic (17.4 MPa) compared to that of airborne particle abrasion (ANOVA, P<0.001). Thermocycling decreased the bond strengths significantly after all of the conditioning methods tested. SIGNIFICANCE: Bond strengths of the luting cement tested on the dental ceramics following surface conditioning methods varied in accordance with the ceramic types. Hydrofluoric acid gel was effective mostly on the ceramics having glassy matrix in their structures. Roughening the ceramic surfaces with air particle abrasion provided higher bond strengths for high-alumina ceramics and the values increased more significantly after silica coating/silanization.     

Influence of various surface-conditioning methods on the bond strength of metal brackets to ceramic surfaces.

With the increase in adult orthodontic treatment comes the need to find a reliable method for bonding orthodontic brackets onto metal or ceramic crowns and fixed partial dentures. In this study, shear bond strength and surface roughness tests were used to examine the effect of 4 different surface conditioning methods: fine diamond bur, sandblasting, 5% hydrofluoric acid, and silica coating for bonding metal brackets to ceramic surfaces of feldspathic porcelain. Sandblasting and hydrofluoric acid were further tested after silane application. A total of 120 ceramic disc samples were produced, and 50 were used for surface roughness measurements. The glazed ceramic surfaces were used as controls. Metal brackets were bonded to the ceramic substrates with a self-curing composite. The samples were stored in 0.9% NaCl solution for 24 hours and then thermocycled (5000 times, 5 degrees C to 55 degrees C, 30 seconds). Shear bond tests were performed with a universal testing device, and the results were statistically analyzed. Chemical surface conditioning with either hydrofluoric acid (4.3 microm) or silicatization (4.4 microm) resulted in significantly lower surface roughness than mechanical conditioning (9.3 microm, diamond bur; 9.7 microm, sandblasting) (P <.001). The surface roughness values reflect the mean peak-and-valley distances. The bond strengths of the brackets bonded to the ceramic surfaces treated by hydrofluoric acid with and without silane (12.2 and 14.7 MPa, respectively), silicatization (14.9 MPa), and sandblasting with silane (15.8 MPa) were significantly higher (P <.001) than those treated by mechanical roughening with fine diamond burs (1.6 MPa) or sandblasting (2.8 MPa). The highest bond strength values were obtained with sandblasting and silicatization with silane or hydrofluoric acid without silane; these fulfilled the required threshold. The use of silane after hydrofluoric acid etching did not increase the bond strength. Diamond roughening and sandblasting showed the highest surface roughness; they can damage the ceramic surface. Acid etching gave acceptable results for clinical use, but the health risks should be considered. The silicatization technique has the potential to replace the other methods; yet cohesive failures were observed in the ceramic during removal of the brackets.     

Effect of surface treatments on the resin bond to zirconium-based ceramic

PURPOSE: This study tested the hypothesis that the tribochemical silica coating on ceramic surfaces increases the bond strength of resin cement to a glass-infiltrated zirconium-based ceramic. MATERIALS AND METHODS: Fifteen blocks of In-Ceram Zirconia from CEREC InLab (5 per group) and 15 composite blocks (Z-250) 5 mm x 5 mm x 4 mm were made. The ceramic surfaces were polished, and the blocks were divided into three groups: (1) airborne abrasion with 110-microm aluminum oxide particles; (2) Rocatec system, tribochemical silica coating; and (3) CoJet system, tribochemical silica coating. The ceramic blocks were cemented to the composite blocks using Panavia F according to the manufacturer's specifications. All samples were stored in 37 degrees C distilled water for 7 days and later sectioned in two axes using a diamond disk under cooling to obtain specimens with a cross-sectional area of approximately 1 mm2 (n = 45). Each specimen was then attached with cyanoacrylate glue to an adapted device for the microtensile test, which was carried out on a universal testing machine. RESULTS: The results were subjected to ANOVA and Tukey's test. Group 2 (23.0+/-6.7 MPa) and group 3 (26.8+/-7.4 MPa) showed greater bond strength than group 1 (15.1+/-5.3 MPa). There was no significant difference between groups 2 and 3. All failures were in the adhesive zone. CONCLUSION: The hypothesis was confirmed--the tribochemical systems increased the bond strength between Panavia F and In-Ceram Zirconia.     

Surface conditioning of a composite used for inlay/onlay restorations: effect on muTBS to resin cement

PURPOSE: To assess the effect of the composite surface conditioning on the microtensile bond strength of a resin cement to a composite used for inlay/onlay restorations. MATERIALS AND METHODS: Forty-two blocks (6 x 6 x 4 mm) of a microfilled composite (Vita VMLC) were produced and divided into 3 groups (N = 14) by composite surface conditioning methods: Gr1--etching with 37% phosphoric acid, washing, drying, silanization; Gr2--air abrasion with 50-lm Al203 particles, silanization; Gr3--chairside tribochemical silica coating (CoJet System), silanization. Single-Bond (one-step adhesive) was applied on the conditioned surfaces and the two resin blocks treated with the same method were cemented using RelyX ARC (dual-curing resin cement). The specimens were stored for 7 days in water at 37 degrees C and then sectioned to produce nontrimmed beam samples, which were submitted to microtensile bond strength testing (muTBS). For statistical analysis (one-way ANOVA and Tukey's test, alpha = 0.05), the means of the beam samples from each luted specimen were calculated (n = 7). RESULTS: muTBS values (MPa) of Gr2 (62.0 +/- 3.9a) and Gr3 (60.5 +/- 7.9a) were statistically similar to each other and higher than Gr1 (38.2 +/- 8.9b). The analysis of the fractured surfaces revealed that all failures occurred at the adhesive zone. CONCLUSION: Conditioning methods with 50-lm Al203 or tribochemical silica coating allowed bonding between resin and composite that was statistically similar and stronger than conditioning with acid etching.     

Evaluation of failure characteristics and bond strength after ceramic and polycarbonate bracket debonding: effect of bracket base silanization

The objectives of this study were to evaluate the effect of silanization on the failure type and shear-peel bond strength (SBS) of ceramic and polycarbonate brackets, and to determine the type of failure when debonded with either a universal testing machine or orthodontic pliers. Silanized and non-silanized ceramic and polycarbonate brackets (N = 48, n = 24 per bracket type) were bonded to extracted caries-free human maxillary central incisors using an alignment apparatus under a weight of 750 g. All bonded specimens were thermocycled 1000 times (5-55 degrees C). Half of the specimens from each group were debonded with a universal testing machine (1 mm/minute) to determine the SBS and the other half by an operator using orthodontic debonding pliers. Failure types of the enamel surface and the bracket base were identified both from visual inspection and digital photographs using the adhesive remnant index (ARI) and base remnant index (BRI). As-received ceramic brackets showed significantly higher bond strength values (11.5 +/- 4.1 MPa) than polycarbonate brackets [6.3 +/- 2.7 MPa; (P = 0.0077; analysis of variance (ANOVA)]. Interaction between bracket types and silanization was not significant (P = 0.4408). Silanization did not significantly improve the mean SBS results either for the ceramic or polycarbonate brackets (12.9 +/- 3.7 and 6.3 +/- 2.7 MPa, respectively; P = 0.4044; two-way ANOVA, Tukey-Kramer adjustment). There was a significant difference between groups in ARI scores for ceramic (P = 0.0991) but not polycarbonate (P = 0.3916; Kruskall-Wallis) brackets. BRI values did not vary significantly for ceramic (P = 0.1476) or polycarbonate (P = 0.0227) brackets. Failure type was not significantly different when brackets were debonded with a universal testing machine or with orthodontic debonding pliers. No enamel damage was observed in any of the groups.     

Comparison of shear bond strength of three bonding agents with metal and ceramic brackets.

Shear bond strengths of a light-cured composite resin, a light-cured glass ionomer cement, and a light-cured compomer used with metal and ceramic brackets were compared, and ARI scores were evaluated. Ceramic brackets showed statistically higher shear bond strengths than metal brackets when bonded with all test materials (p<0.001). When used with metal brackets, the light-cured glass ionomer cement (LCGIC) and compomer materials demonstrated statistically lower shear bond strengths than the light-cured composite (p<0.01 and p<0.001, respectively). When used with ceramic brackets, LCGIC was found to have significantly lower shear bond strength than the composite material (p<0.001). Despite its relatively low shear bond strength, LCGIC demonstrated optimal bonding values (8.39+/-3.24 MPa) with ceramic brackets. Bond failures within the LCGIC groups occurred at the adhesive-tooth interface, whereas in the compomer and composite groups, failures were detected at the adhesive-bracket interface. In the metal bracket group, clinically acceptable shear bond strength was obtained only with the composite resin (7.06+/-1.65 MPa). Compomer and LCGIC demonstrated values well below the accepted standard for metal brackets (4.32+/-1.75 MPa and 4.45+/-1.06, respectively), while in the ceramic bracket group, values for composite and compomer were above the desired level (14.40+/-5.88 MPa and 12.31+/-6.09, respectively). LCGIC showed reasonably good bond strength with ceramic brackets, suggesting that this material may be considered suitable for use with ceramic brackets in clinical situations where moisture cannot be controlled.     

Microtensile bond strength of a resin cement to glass infiltrated zirconia-reinforced ceramic: the effect of surface conditioning.

OBJECTIVES: This study evaluated the effect of three surface conditioning methods on the microtensile bond strength of resin cement to a glass-infiltrated zirconia-reinforced alumina-based core ceramic. METHODS: Thirty blocks (5 x 5 x 4 mm) of In-Ceram Zirconia ceramics (In-Ceram Zirconia-INC-ZR, VITA) were fabricated according to the manufacturer's instructions and duplicated in resin composite. The specimens were polished and assigned to one of the following three treatment conditions (n=10): (1) Airborne particle abrasion with 110 microm Al(2)O(3) particles + silanization, (2) Silica coating with 110 microm SiO(x) particles (Rocatec Pre and Plus, 3M ESPE) + silanization, (3) Silica coating with 30 microm SiO(x) particles (CoJet, 3M ESPE) + silanization. The ceramic-composite blocks were cemented with the resin cement (Panavia F) and stored at 37 degrees C in distilled water for 7 days prior to bond tests. The blocks were cut under coolant water to produce bar specimens with a bonding area of approximately 0.6mm(2). The bond strength tests were performed in a universal testing machine (cross-head speed: 1mm/min). The mean bond strengths of the specimens of each block were statistically analyzed using ANOVA and Tukey's test (alpha相似文献   

Repair bond strength of a resin composite to alumina-reinforced feldspathic ceramic

This study compared the microtensile bond strength of a repair resin to an alumina-reinforced feldspathic ceramic (Vitadur-alpha, Vita) after 3 surface conditioning methods: Group 1, etching with 9.6% hydrofluoric acid for 1 minute plus rinsing and drying, followed by application of silane for 5 minutes; group 2, airborne particle abrasion with 110-mm aluminum oxide using a chairside air-abrasion device followed by silane application for 5 minutes; group 3, chairside tribochemical silica coating with 30-microm SiOx followed by silane application for 5 minutes (N = 30). Group 1 presented the highest mean bond strength (19.7 +/- 3.8 MPa), which was significantly higher than those of groups 2 (10 +/- 2.6 MPa) and 3 (10.4 +/- 4 MPa) (P < .01). Scanning electron microscope analysis of the failure modes demonstrated predominantly mixed types of failures, with adhesive and/or cohesive failures in all experimental groups.     

硅涂层对牙科氧化铝陶瓷与树脂粘结强度的影响

目的 探讨在牙科氧化铝陶瓷表面进行SiO2水溶胶涂层对陶瓷与树脂粘结强度的影响.方法 32个氧化铝陶瓷试件根据计算机产生的伪随机数字表分为4组,每组8个,采用溶胶-凝胶法在试件表面分别进行20%SiO2水溶胶涂层+硅烷偶联剂(A组)、30%SiO2水溶胶涂层+硅烷偶联剂(B组)、40%溶胶涂层+硅烷偶联剂(C组)和硅烷偶联剂(对照组)处理,应用傅立叶红外光谱、扫描电镜、X射线能谱仪进行分析.制作陶瓷-复合树脂粘结体,剪切法测试各组剪切粘结强度.结果 溶胶-凝胶法可在氧化铝陶瓷试件表面制得纳米硅涂层.热处理后A、B、C 3组试件Si-O-Si反对称伸缩振动吸收峰、对称伸缩振动吸收峰、弯曲振动吸收峰均增强;扫描电镜显示纳米氧化硅粒子分布较均匀,局部粒子产生团聚;试件表面硅元素含量均明显增加.A、B、C组试件与树脂的剪切粘结强度分别为(3.196±0.171)Mpa、(4.852±0.178)Mpa、(3.576±0.671)Mpa,与对照组[(1.881±0.156)Mpa]相比,差异均有统计学意义(P＜0.05);B组的剪切粘结强度与A、C组相比,差异有统计学意义(P＜0.05).结论 3种浓度硅溶胶可在牙科氧化铝陶瓷表面制得纳米硅涂层.纳米硅涂层可显著提高氧化铝陶瓷与树脂的剪切粘结强度.其中30%浓度SiO2水溶胶制备的硅涂层提高剪切粘结强度的效果最明显.     

Bond strength of a resin cement to high-alumina and zirconia-reinforced ceramics: the effect of surface conditioning

PURPOSE: The aim of this study was to evaluate the effect of two surface conditioning methods on the microtensile bond strength of a resin cement to three high-strength core ceramics: high alumina-based (In-Ceram Alumina, Procera AllCeram) and zirconia-reinforced alumina-based (In-Ceram Zirconia) ceramics. MATERIALS AND METHODS: Ten blocks (5 x 6 x 8 mm) of In-Ceram Alumina (AL), In-Ceram Zirconia (ZR), and Procera (PR) ceramics were fabricated according to each manufacturer's instructions and duplicated in composite. The specimens were assigned to one of the two following treatment conditions: (1) airborne particle abrasion with 110-microm Al2O3 particles + silanization, (2) silica coating with 30 microm SiOx particles (CoJet, 3M ESPE) + silanization. Each ceramic block was duplicated in composite resin (W3D-Master, Wilcos, Petrópolis, RJ, Brazil) using a mold made out of silicon impression material. Composite resin layers were incrementally condensed into the mold to fill up the mold and each layer was light polymerized for 40 s. The composite blocks were bonded to the surface-conditioned ceramic blocks using a resin cement system (Panavia F, Kuraray, Okayama, Japan). One composite resin block was fabricated for each ceramic block. The ceramic-composite was stored at 37 degrees C in distilled water for 7 days prior to bond tests. The blocks were cut under water cooling to produce bar specimens (n = 30) with a bonding area of approximately 0.6 mm2. The bond strength tests were performed in a universal testing machine (crosshead speed: 1 mm/min). Bond strength values were statistically analyzed using two-way ANOVA and Tukey's test (< or = 0.05). RESULTS: Silica coating with silanization increased the bond strength significantly for all three high-strength ceramics (18.5 to 31.2 MPa) compared to that of airborne particle abrasion with 110-microm Al2O3 (12.7-17.3 MPa) (ANOVA, p < 0.05). PR exhibited the lowest bond strengths after both Al2O3 and silica coating (12.7 and 18.5 MPa, respectively). CONCLUSION: Conditioning the high-strength ceramic surfaces with silica coating and silanization provided higher bond strengths of the resin cement than with airborne particle abrasion with 110-microm Al2O3 and silanization.     

Evaluation of metal bond strength to dentin and enamel using different adhesives and surface treatments

Because adherence of base metal alloys is important for the long-term clinical success of adhesive fixed partial dentures, it has been necessary to improve adhesion to metal substrate by using different surface treatments. This study used different surface conditioning methods and two different luting resins to evaluate the shear bond strength of base metal alloys to dentin and enamel. Sixty noncarious freshly extracted human teeth were mounted in a plastic holder filled with autopolymerized acrylic resin. After the roots were removed and 30 flat enamel and 30 flat dentin surfaces were exposed, the specimens were divided randomly into two main luting cement groups. Sixty nickel chromium (NiCr) metal specimens were fabricated and subjected to three different surface conditioning procedures: sandblasting with 50 microm aluminum oxide, tribochemical silica coating, and a combination of the two. Scanning electron mircoscopy (SEM) evaluations revealed mainly cohesive failures. Self-cure adhesive resulted in higher bond strengths to dental substrates. Higher bond strengths were achieved through a combination of sandblasting and tribochemical silica coating; however, further clinical research is required. A surface treatment that combines sandblasting with tribochemical silica coating can achieve a more effective bond for adhesive restorations with metal substrates.     

不同表面处理对氧化锆与牙釉质黏结强度的影响

目的:比较4种表面处理方法对氧化锆陶瓷与牙釉质黏结强度的影响,为临床应用提供参考。方法:将切割烧结后的Lava氧化锆瓷块(2.7 mm×2.7 mm×5 mm)40件分为4组,分别经喷砂、喷砂/硅烷偶联剂、喷砂/CoJet Sand/硅烷偶联剂、无处理4种表面处理后,用RelyX Unicem与牙釉质黏结,测试剪切黏结强度,采用SPSS20.0软件包对数据进行统计学分析,利用扫描电镜观察断面模式。结果:喷砂/CoJet Sand/硅烷偶联剂组的剪切强度显著高于其他各组(P<0.001),且人工老化试验前、后无显著差异(P=0.595)。电镜观察该组断面模式,未发现“黏结界面破坏型”。结论:氧化锆表面经摩擦化学法硅涂层和硅烷偶联剂联合处理,能够有效提高氧化锆的黏结强度和耐久性。