Influence of different surface treatments on zirconia/resin shear bond strength using one-bottle universal adhesive

ABSTRACT

This study was designed to evaluate the effect of different treatments on the zirconia/resin shear bond strength (SBS) using commercial one-bottle universal adhesive. Zirconia discs with different surface treatments (blank control; airborne-particle-abrasion; glazing) were bonded to the bovine enamel surfaces using one-bottle universal adhesive. All specimens were tested for SBS (MPa) before and after 10000 thermocycles. Statistically analysis were conducted by using one-way analysis of variance and multiple-comparison least significant difference tests (α = 0.05). Airborne-particle-abrasion group showed higher SBS (36.19 ± 11.86) than control group (14.98 ± 5.90) and glazing group (10.63 ± 5.39) (p < 0.05). After thermocycling test, the SBS significantly decreased for control group (8.84 ± 2.55) and glazing group (6.18 ± 2.78) while not for airborne-particle-abrasion group (41.5 ± 7.95). One-bottle universal adhesives combined with airborne-particle-abrasion showed quite high SBS of zirconia/resin, which was appropriate for bonding of zirconia restoration.     

The influence of retention hole and adhesive systems on the shear bond strengths of resin composite to amalgam

The aim of the study is to evaluate the influence of surface-treatment methods with and without the use of a retention hole on the shear bond strength of a resin composite adhered to amalgam using an adhesive system. Amalgam specimens were divided into six groups. Group 1 (Bur) specimens were roughened with a diamond bur, Group 2 (Al₂O₃) specimens were sandblasted with a 50?μm aluminum oxide powder, Group 3 (CoJet^®) specimens were sandblasted with 30?μm CoJet^® Sand, Group 4 (Bur?+?Rh) specimen surfaces were prepared with a retention hole 1?mm in diameter and 1?mm deep and roughened with a diamond bur, Group 5 (Al₂O₃?+?Rh) specimens were also prepared with a retention hole and sandblasted with 50?μm aluminum oxide powder, and Group 6 (CoJet^®?+?Rh) surfaces were prepared with a retention hole and sandblasted with 30?μm CoJet^® Sand. Resin composite cylinders were bonded onto the amalgam surfaces using Xeno^® IV, Optibond? All-In-One, Clearfil? SE Bond, Adper? Single Bond Plus, and Scotchbond? Multi-Purpose adhesive systems. In addition, silane (Monobond S) was used for Groups 5 and 6. The shear bond was determined and statistically analyzed using two-way analysis of variance and post hoc Tukey’s tests (p?≤?0.05). The surface treatment significantly affected the shear bond strengths of the adhesive systems. The shear bond strengths of Optibond? All-In-One (2.661?±?0.48?MPa) in Group 1 and Scotchbond Multi-Purpose (3.818?±?0.98) in Group 4 were significantly higher than those of the other adhesive systems. Silica coating of the amalgam surface significantly improved the shear bond strength of the resin composites. The addition of a retention hole on the amalgam affects the bonding strength of the composite adhesion.     

表面处理方法对胶粘剂性能的影响

采用不同的表面处理方法处理粘接接头,在湿热老化条件下通过元素分析法测定了样品中碳、硅、氧的含量,以及对胶粘剂粘接接头剥离强度、吸水率,玻璃化温度等湿热老化性能进行了考查,得出最佳处理粘接接头的方法。     

Effectiveness of different surface cleaning methods on the shear bond strength of resin cement to contaminated zirconia: an in vitro study

The purpose of this in vitro study was to evaluate and compare the effectiveness of different surface cleaning methods on the shear bond strength (SBS) of zirconia ceramic surfaces. Seventy polished and cleaned zirconia disk specimens of 8 mm in diameter and 3.4 mm in thickness were immersed in fresh saliva. They were then pressed into a freshly mixed silicone disclosing medium. Six different cleaning methods were applied to the tested groups; they were airborne-particle abraded (AA), covered with a cleaning paste (Ivoclean®) (IV), etched with orthophosphoric acid (PA), immersed in alcohol (AL), rinsed with tap water only (WA), or cleaned with steam (SC). No surface cleaning was done after saliva immersion and silicone disclosing medium contamination to the control group (CC). The specimens were then bonded to an adhesive resin cement using polyethylene tubes. SBS was determined using a universal testing machine at a crosshead speed of 1 mm/min. The specimens were also examined with a scanning electron microscope and a stereomicroscope. Group AA yielded the highest SBS value (7.01 ± 1.4 MPa) among the groups, while Group WA had the lowest SBS value (3.03 ± 0.8 MPa). The SBS values of Group AA (7.01 ± 1.4 MPa) and IV (6.2 ± 1.7 MPa) were also significantly higher than those of the remaining four groups (p < 0.05). Within the limitations of this in vitro study, it was concluded that among the various cleaning methods tested, airborne-particle abrasion and Ivoclean® paste were effective in cleaning the zirconia surface.     

Effect of surface conditioning methods,adhesive systems and resin composite on repair strength of dimethacrylate and silorane resin composites

This study evaluated the effect of surface conditioning methods and adhesive systems on the repair bond strength of resin composites. Specimens (FLS: Filtek LS) (N = 144) were prepared using a silicone matrix. The specimens were stored in distilled water and then were randomly divided into the twelve groups (n = 12) according to the surface conditioning method (unground or diamond bur) and adhesive system (no adhesive, LS: Filtek LS, AS: Adper Scotchbond SE Plus) and resin composite (FLS: Filtek LS; FS: Filtek Supreme). The specimens were fixed in an hourglass-shaped silicone matrix and the other half of the specimen was restored. Hourglass-shaped specimens (n = 12) were used as positive control to measure the cohesive strength of the resin composite (Filtek LS). Microtensile bond test was performed (0.5 mm/min) and failure types were analyzed. Data were analyzed using two-way analysis of variance, Tukey’s and Dunnett’s tests (α = 0.05). Adhesive protocol and resin composite significantly affected the results (p < 0.05). For the FS composite, the highest results were obtained using LS adhesive with (18.4 ± 7.7) and without (18.8 ± 4.8) bur roughening. For FLS composite, the highest results were obtained using AS adhesive with (33.2 ± 7.1) and without (25.7 ± 3.6) bur roughening. Without the use of adhesive resin, significantly lower bond strength results were observed with both LS (5 ± 2.1, 4.5 ± 1.5) and FLS (2.2 ± 1.2, 4.4 ± 1.1) for unground and diamond bur roughened groups, respectively (p < 0.0001). Cohesive strength of the FLS (52.3 ± 7.6) was significantly higher than any of the repaired groups (p < 0.0001). FS–LS combination and the groups repaired without adhesive presented more adhesive (Type I) failures.     

The effect of different surface pretreatments on the bond strength of veneering resin to polyetheretherketone

The aim of this study was to investigate the effect of different surface pretreatment methods on the bond strength of veneering resin to polyetheretherketone (PEEK) based aesthetic frameworks. Five hundred and forty PEEK disks were fabricated and divided into 6 pretreatment groups (n = 90); (C) untreated control group, (B) airborne-particle abrasion, (S) silica coating, (L) etching with Er:YAG (erbium-doped yttrium aluminium garnet) laser, (LB) etching with Er:YAG laser and airborne-particle abrasion and (LS) etching with Er:YAG laser and silica coating. After topographical surface examinations, specimens were conditioned with adhesive and veneering resin was polymerized onto the PEEK specimens. Twenty-four hours after veneering, specimens were subjected to thermal aging. Afterwards, shear bond strength (SBS) tests were performed and the obtained data were analyzed with one-way ANOVA and Tukey test at a significance level of α = .05. Group B (1.58 ± 0.15 μm), Group L (1.79 ± 0.29 μm), Group LB (2.20 ± 0.23 μm) and Group LS (2.31 ± 0.52 μm) demonstrated significantly higher surface roughness (SR) values compared to Group C (1.03 ± 0.11 μm). Group B (10.97 ± 2.88 MPa), Group S (12.07 ± 2.82 MPa), Group LB (12.09 ± 2.08 MPa) and Group LS (13.14 ± 1.45 MPa) demonstrated significantly higher SBS values compared to Group C (6.35 ± 1.21 MPa). Airborne-particle abrasion, silica coating or their combined use with Er:YAG laser system establish durable bond between PEEK and resin; however, only Er:YAG laser treatment has no positive effect on resin-PEEK bond.     

Effects of surface treatments on the shear bond strength of luting cements to zirconia

Objective: The aim of this in vitro study was to evaluate the effect of surface treatments on the shear bond strength of resin cements to zirconia. Material and methods: Sintered zirconia specimens (n = 192) were divided into four different surface treatment groups: control (no treatment); airborne-particle abrasion; glaze layer and hydrofluoric acid (HF) application, and hot etching solution application. Then, each group was divided into four subgroups (n = 12), and three different resin cements were applied to the zirconia surfaces. The shear bond strength value of each specimen was measured after 5000 thermo cycles. The failure types were examined with a stereomicroscope and the effects of the surface treatments were evaluated with a scanning electron microscope. Results were analyzed using analysis of variance and Tukey’s post hoc tests (α = 0.05). Results: The surface treatment and resin cement type significantly affected the bond strength results (p < 0.05). For all resin cements, the airborne-particle abrasion treatment increased the shear bond strength values (p < 0.05). The glaze layer & HF application increased shear bond strength values for all groups, except the Single Bond Universal-RelyX Unicem Aplicap group (p < 0.05). The surface roughness values of airborne-particle abraded specimens were similar to comparable values for specimens from the control group and the hot etching solution group (p > 0.05). The glaze layer & HF application group produced the highest surface roughness values (p < 0.05). Conclusion: The results of this study recommend using the appropriate combination of surface treatment and adhesive/silane coupling agent to achieve durable zirconia-resin bonding.     

Cold-setting adhesives for repair purposes using various surface preparation methods

The effect of six surface preparation methods on the performance of five adhesives was studied. Comparisons were made using the lap shear test and the Boeing wedge test. It was concluded that only chromic acid etching and anodizing and phosphoric acid anodizing are suitable for permanent primary structure repairs. However, grit blasting and some paste etches may be acceptable for temporary primary structure repairs and for routine secondary structure repairs. Some case histories of actual repairs are included.     

Effect of adhesive application on the shear bond strength of flowable composite resins and APC plus to orthodontic molar tubes

Objectives: To evaluate the effect of adhesive application on the shear bond strength (SBS) of orthodontic tubes to acid-etched human enamel when using different flowable composite resins and the APC Plus system (APC). Study design: One hundred metal tubes were bonded to human third molars, which were randomly divided into five groups: Tetric EvoFlow (TF); Wave mv Flow (W); Transbond Supreme LV (S); Transbond XT (XT); and APC. For each experimental group, half of the specimens were bonded in combination with Transbond XT adhesive. After 72?h, an SBS test was performed using a universal testing machine. Two-way analysis of variance (ANOVA) was run for multiple comparison tests and for comparing the mean SBS among the 10 subgroups to evaluate the effect of both the composite and the adhesive factors. Then, a Student-Newman-Keuls test was used for pairwise comparisons using the highest mean SBS group as reference. Adhesive Remnant Index scores were determined for the teeth after failure and compared by χ ²-test. Two representative molar surfaces from the 10 subgroups were assessed under scanning electron microscope. Results: The application of adhesive did not have a significant effect, but there was a marked tendency toward the influence of the factor composite on SBS. The mean SBS of tubes bonded with XT with adhesive was significantly higher than that of those bonded with APC with adhesive, TF with and without adhesive, and S with adhesive. Conclusion: Flowable composites and the APC system without intermediate bonding resin could be conveniently applied for orthodontic tube bonding.     

Effect of adhesive application on the shear bond strength of refrigerated and pre-heated of different composite resins to orthodontic molar tubes

Objective: To evaluate the effect of adhesive application on the shear bond strength (SBS) of orthodontic tubes to acid-etched human enamel using different temperatures and orthodontic composite resins. Methods: One hundred and twenty metal tubes were bonded to human third molars, which were randomly divided into three groups depending on the composite used: Transbond XT (XT); Transbond Supreme LV (LV); and Light Bond (LB). Each group was divided into four subgroups depending on the temperature (5°, 20°, 40°, and 60°) applied to the composite before cementing. For each experimental subgroup, half the specimens were bonded in combination with XT Primer. After 72?h, a SBS test was performed using a universal testing machine. Statistical analysis was performed using ANOVA, post hoc intergroup comparisons, chi-square test, and linear regression. Two representative molar surfaces from each subgroup were assessed under Scanning electron microscope. Results: The composite type only influenced XT regarding LB. The use of adhesive does not affect the SBS values of any composite. The flowable composites with adhesive containing zirconia (LV) as a filler showed lower SBS when cooled to 5?°C and when increases the temperature from 40?°C. Whether adhesive was used or not, composites with silica as filler (LB) showed lower SBS at 60?°C and increased to 5?°C. Conclusions: For all composites, from 20?°C, SBS values tend to increased and started to decline at 40°C except when adhesive is applied to the quartz-filled composite, which continues to increase, and the silica-filled composite without adhesive, which tend to decreases from 5?°C.     

Microtensile bond strength of composite-to-composite repair with different surface treatments and adhesive systems

Objectives: The purpose was to investigate the effect of different surface treatments and bonding agents on the repair bond strength of different resin-based restorative materials by microtensile bond strength (μTBS) testing protocol. Materials and Methods: 24 Grandio SO(VOCO) and 24 Filtek Z250(3?M) resin composite blocks were prepared. Half of the samples (N?=?12) were diamond bur-roughened and the other half (N?=?12) were sandblasted by 50?μm aluminum oxide particles. They were further divided into four sub-groups (n?=?3) and received the following: Sub-Group1: Adper Single Bond2 (Etch&Rinse) (3?M); Sub-Group2: Clearfil SE (Self-etch) (Kuraray); Sub-Group3: Beauty Bond (HEMA-free all-in-one) (Shofu); Sub-Group4: All Bond3 (HEMA-free, hydrophobic, etch&rinse) (Bisco). The samples were repaired by Filtek Z250 to form a block. All of the resultant sub-groups combinations consisted of one of the composite type, surface treatment type, and adhesive systems. A total of 18 groups were prepared including 2 homogeneous blocks. They were thermocycled and μTBS measurements were performed. Data were statistically analyzed with Kruskall–Wallis and Mann–Whitney U tests. Results: The experimental regroups’ μTBS reached to 34.67–66.36% and 43.44–95.52% of the cohesive bond strength for Grandio SO and Z250, respectively. The pre-existing composite type is found to be statistically important. When the surface is bur-finished Grandio performed better; when air-abrasion is considered Z250 showed higher bond strength. All-in-one adhesive system produced the weakest bond strength at all parameters. Conclusion: It may be suggested that when the pre-existing composite is unknown, air-abrasion may be performed with etch&rinse or two-step self-etch adhesives.     

Adhesion of resin cement to contemporary hybrid ceramic and polymeric CAD/CAM materials: effect of conditioning methods and ageing

This study assessed the effect of different surface conditioning methods and ageing protocols on adhesion of resin cement to hybrid ceramic and polymeric CAD/CAM materials. CAD/CAM materials (n?=?360, n?=?30 per group), namely (a) Lithium disilicate (IPS e.max CAD-LIS), (b) Zirconia (IPS e.max ZirCAD-ZIR), (c) Polymer (Lava Ultimate-LAV), (d) Polymer infiltrated ceramic network (Enamic-ENA), (e) Polymer infiltrated ceramic (Experimental-1-CS1), (f) Polymer infiltrated ceramic (Experimental-2-CS2), (g) Lithium disilicate reinforced alumina (n!ce-NIC) were cut into slices (3?×?6 × 8?mm³) and conditioned: (a) Method 1: 5% hydrofluoric acid etching (H)+silane and (b) Method 2: Silica coating (CoJet (A)+silane). Group LIS was conditioned with only Method 1 and Group ZIR only with Method 2 (control). Resin cement (Variolink Esthetic II) was bonded onto the conditioned specimens and photopolymerized. One-half of the specimens was subjected to ageing (thermocycling 5–55°, 5000 cycles) and the other half was stored in distilled water (37?°C, 24?h). The resin-substrate interface was loaded under shear forces in a Universal Testing Machine (1?mm/min). Data (MPa) were analyzed using two-way ANOVA and Tukey`s tests (α?=?0.05). Substrate type, conditioning method and ageing had a significant effect on adhesion values (p?<?.05). In aged conditions, ENA-H, ENA-A, LAV-H, LAV-A, CS2-A (15?±?4 – 11.6?±?5) showed no significant difference (p?>?.05), with the CS2-A (15?±?4) showing the least reduction (5.5%) compared to all other groups (5.8–62.6%). CS1-A (100%) followed by ENA-H, ENA-A (93%), CS2-A (80%) presented the highest incidence of cohesive failures after ageing.     

Bond strength and durability of universal adhesive agents with lithium disilicate ceramics: A shear bond strength study

The aim was to assess the shear bond strength (SBS) of lithium disilicate (LD) ceramic to resin composite with different universal adhesives, duration of ageing and silane. One hundred and twenty LD ceramic discs were processed, fired and etched (HF acid 5%) for 20 s (sec). All specimens were divided into 12 groups (n = 10), based on different combinations of, 3 different universal adhesives [Scotchbond (SB) Universal Adhesive, All-Bond (AB) Universal, and Futurabond U (FU)], silane and different duration of ageing [24 h and 3 months]. Composite resin cylinders (Tetric ceram) (3mm × 2 mm) were formed using bonding jig on ceramic and were light-cured. The specimens in groups 1–6 and 7–12 were stored in distilled water (37 °C) for 24 h and 3 months (thermocycling -5000 cycles 5–55 °C/30 s dwell time) before being subjected to bond strength testing respectively. Using universal testing machine shear bond test was performed at a crosshead speed of 1 mm/min. Failure modes and fracture patterns were assessed using stereomicroscope and scanning electron microscope. Analysis of variance was performed to analyze data. SBS was significantly higher with silane than without silane (p < 0.01), regardless of the type of adhesive or storage duration. Specimens tested at 24 h storage showed significantly higher (p < 0.01) SBS than specimens tested after 3-months. A comparison among different universal adhesives showed significantly distinct bond strength (p < 0.01). Optimal bonds to LD were achieved by application of silane. While ageing through storage had a negative impact on the SBS, it varied among different adhesives.     

Effects of different surface treatments on shear bond strength between ceramic systems and metal brackets

The aim of this study was to evaluate the shear bond strength of orthodontic brackets bonded to different kinds of ceramic surfaces after different surface conditioning methods. A total of 120 ceramic disks were divided into two main groups in terms of feldspathic or lithium disilicate. Each ceramic group was further subdivided into six subgroups depending on surface treatment (n = 10). The ceramic surfaces were conditioned by one of the following methods: Group C: control group; Group P: %37.5 orthophosphoric acid; Group HF: %9.6 hydrofluoric acid; Group L: Nd-YAG laser irradiation; Group SB: sandblasting with 50 µm Al₂O₃ particles; and Group DB: grinding with a diamond bur. Surface roughness value was evaluated with a digital profilometer. Surface topographies of one specimen from each group were observed by atomic force microscopy (AFM) after surface treatments. All samples were primed with silane before the bracket bonding, including the control group. Metal brackets were bonded to the specimens with a light curing composite resin. The samples were stored in distilled water for 24?h and thermocycled 2500× at 5 and 55 ºC for 30?s. Shear bond strengths between the ceramic surface and the bracket were measured with a universal testing machine at a crosshead speed of 0.5 mm/min. Failure modes were classified as adhesive, cohesive, or mixed. Data were analyzed using ANOVA and Tukey's tests (α = .05). Group SB had significantly rougher surface compared with the other groups in each ceramic system (p < .05), and Group SB demonstrated significantly higher shear bond strengths than other groups as well. Within the limitations of this study, surface conditioning methods, except for sandblasting and grinding, were associated with lower shear bond strengths; however, thermocycling may have had negative effects on bond strengths of specimens. Furthermore, in each ceramic system, there was a significant difference between surface-conditioning methods and surface roughness with regard to shear bond strength.     

Influence of surface treatment on the durability of stainless steel sheets bonded with epoxy

Fifteen different surface treatments were used to bond AISI 304 stainless steel. The objectives of the programme were to select treatments able to produce durable adhesive bonds and to contribute to the understanding of interface bonding phenomena and of phenomena responsible for debonding while ageing. Peel and sheer tests were carried out to assess the behaviour of the bonded joints at the initial state and after ageing. The test results indicate that only two treatments, sulphuric chromic acid anodization and nitric acid anodization, exhibit a high performance level after exposure to a moist environment. The chemical and physical properties of surfaces were determined. The surface morphology was observed with a scanning electron microscope, and chemical composition was studied by X-ray photoelectron spectroscopy and secondary ion mass spectrometry. A correlation between bond durability, surface morphology, and oxide film composition was established.     

The shear bond strength of repaired high-viscosity bulk-fill resin composites with different adhesive systems and resin composite types

This study compared the effect of different adhesive systems and composite resins on the shear bond strength (SBS) of repaired high-viscosity bulk-fill composites(Tetric EvoCeram Bulk Fill) and investigated failure modes. One hundred twenty cylindrical bulk-fill composite blocks (diameter 5?mm) were fabricated and thermocycled for 5000 cycles (5–55?°C). Specimens were roughened by diamond bur and divided into 8 groups (n?=?15). Bulk-fill blocks were repaired with the same material or nanohybrid composite resin(Tetric EvoCeram Nanohybrid) (diameter 3?mm) using different adhesive systems:Tetric N-Bond Universal (TSE);37% phosphoric acid etching?+?Tetric N-Bond Universal (TER); Clearfil SE Bond (CSE); 37% phosphoric acid etching?+?Adper^TMSingle Bond 2(SB). After repair procedures, all specimens were thermocycled again. The shear bond strengths were measured for all specimens using a universal test machine (crosshead speed of 1?mm/min). Cohesive strengths of bulk-fill composites were measured and described as control group. Debonded surfaces were observed with a stereomicroscope under 10x magnification to determine mode of failure. The SBS data of all groups was statistically analyzed by two-way ANOVA and Bonferroni correction test (p?<?0.05). The specimens repaired with bulk-fill composites showed significantly higher SBS values (25.86?±?5.74, 27.05?±?4.93, 24.49?±?6.95MPa) than those with nanohybrid composites (20.41?±?3.70, 22.08?±?6.37, 18.74?±?6.40?MPa) for TER,CSE,SB, respectively (p?<?0.05). There were no significant differences in SBS according to the type of adhesive systems for both repair materials (p?>?0.05). The predominant mode of failure was a mixed type in the restorative material except for the ones repaired with nanohybrid composites using Adper^TMSingle Bond 2. High-viscosity bulk-fill composites could be successfully repaired with the same materials. SBS of repaired bulk-fill composites reached cohesive strength for all tested groups.     

Evaluation of different desensitizing agents effect on shear bond strength of adhesive resin cement to dentin

Desensitizing agents can inhibit the bonding strength between dentin and adhesive resin cement. This study evaluated the effects of different desensitizing agents on the shear bond strength of adhesive resin cement to dentin. Sixty freshly extracted and caries free teeth were classified into five experimental groups, randomly (n?=?12). Each group was treated with a different desensitizing agent (Teethmate, Shield Force Plus, Admira Protect and Ultra-Ez) respectively, except for an untreated control group. After desensitizing agents and adhesive resin cement were applied to each dentin surface, all specimens were stored in incubator at 37?°C for 24?h. The shear bond strength was tested with a Universal testing machine at a 0.5?mm/min crosshead speed. Data were analysed by using a statistical software (SPSS 22). The results of the measurements were analysed by Kruskal Wallis test with Bonferroni correction and multiple comparisons were made by Wilcoxon test (p???.01). Specimens were examined by a scanning electron microscope, additionally. The Shield Force Plus showed significantly the highest shear bond strength compared with other groups (p?<?.01). Ultra-Ez showed the lowest shear bond strength (p?>?.01). There was no significant difference among Teethmate and Admira Protect groups (p?>?.01). Desensitizing agents containing resin monomers increased the bonding strength, however desensitizers containing calcium phosphate, potassium nitrate and fluoride did not effect the bonding strength of resin cement to dentin.     

Effect of hot-etching treatment on shear bond strength of zirconia to resin cement

ABSTRACT

The purpose of this study was to evaluate the effect of hot-etching surface treatment on the shear bond strength between zirconia ceramics and resin cement. Ceramic cylinders were divided randomly into 10 groups (n?=?10) according to different surface treatments (blank control; airborne particle abrasion; hot-etching for 10?min; hot-etching for 30?min; hot-etching for 60?min) and whether or not performed thermal cycling fatigue test. Flat enamel surfaces, were prepared from human permanent incisors and were bonded to the zirconia discs. All specimens were subjected to shear bond strength test by a universal testing machine. All data were statistically analysed using one-way analysis of variance and multiple comparison least significant difference tests (α?=?0.05). Hot-etching for 60?min treatment produced higher bond strengths than the other treatment. Surface treatment of zirconia with a hot-etching solution might enhance surface roughness and bond strength between zirconia and resin cement.     

Effects of different surface treatments of zirconia on the bond strength of self-adhesive resinous cement

Purpose: The aim of this study was to evaluate the effects of different zirconia surface treatments on the bond strength of two self-adhesive resinous cements (SARC).

Methods: Two hundred and eight cylindrical specimens were obtained from Y-TZP zirconia (half with diameter 3.2 mm and half with 4.8 mm). After sintering and polishing, specimens were divided into four groups (n = 26), according to surface treatment: Control (no treatment); Sandblasting (Al₂O₃ particles); Rocatec (Al₂O₃ particles, tribochemical silica coating and silane application); Laser (Nd: YAG laser: 20 Hz, 100 mJ, 0.2 J/cm²). The surface roughness (Ra) was evaluated after the surface treatments, and the groups were divided into two subgroups (n = 13), according to the SARC tested: RelyX U200 and Bifix SE. The 2.2-mm cylinders were bonded to 4.8-mm cylinders and stressed until failure under shear using a universal testing machine. Bond strength and Ra were analyzed using ANOVA, and Tukey’s test (α = 0.05).

Results: Surface treatment was significant (p < 0.0001), but cement type (p = 0.73) was not. Related to roughness, significant differences were found for the treatment type (p < 0.0001), with laser being the treatment with higher Ra values.

Conclusions: Nd:YAG laser produced a rougher surface and a higher bond strength compared with sandblasting, silicatization, and control groups.     

Two-step vs. one-step conditioning systems and adhesive interface of glass ceramic surface and resin systems

The effect of two-step and one-step ceramic surface conditioning/priming, and subjecting to exposure with boiling water on adhesion strength of resin cements was evaluated. Rectangular shaped specimens were cut from CAD blocks of E-max (Ivoclar Vivadent) and Mark II (VITA Zahnfabrik) and randomly assigned to two main study groups. Group one specimens’ surfaces were conditioned using the two-step conditioning/priming procedure and group two specimens were treated using the one-step conditioning/priming system. After treating, 3 mm thick resin cement layer was applied onto the surface using a split stainless steel mold. Each group was further divided into four subgroups (n = 10) depending on type of resin cement applied and subjecting to exposure in boiling water. Adhesion strength of all the specimens was measured using the universal material testing machine, results were tabulated and subjected to statistical analysis at a significance level of p < 0.05. Adhesive resin showed higher values of 22.05 and 18.65 MPa with E-max and Mark II respectively, and resin composites showed 18.13 and 15.13 MPa with E-max and Mark II respectively, when two-step conditioning system was employed. Majority of the adhesive resin specimens showed cohesive failure in cement. Subjecting the specimens to exposure in boiling water for 24 h not only showed adhesive failure but also significantly reduced adhesion strength of adhesive resin and resin composite. The significance of the study is that, the traditional two-step ceramic surface conditioning is more effective than the one-step conditioning and unfilled adhesive resin provides better adhesion strength.