Effect of air-particle pressures on the surface topography and bond strengths of resin cement to the hybrid ceramics

How the repair bonding strength of hybrid ceramic CAD/CAM blocks is influenced by the use of surface treatments and universal adhesives

We examined how different methods of surface treatment and different universal adhesives with or without extra silane affected the repair bonding strength of hybrid ceramic CAD/CAM restorations. Cerasmart specimens (n=320) were subjected to thermocycling and assigned to the following surface pretreatment protocols: control, diamond bur (DB), hydrofluoric acid (HF), and tribochemical silica coating (TSC). Half the specimens received a coating of silane, followed by application of the universal adhesives Futurabond M+ (FMU), Tokuyama Universal Bond (TUB), Single Bond Universal (SBU), or Clearfil Universal Bond Quick (CUQ) (n=10). A hybrid composite resin was used to simulate repair; then the specimens underwent further thermocycling. Shear bond strength (SBS) was determined and modes of failure were examined. The TSC-CUQ silane (-) group showed the highest SBS values. The best repairs were obtained when the surface was treated with TSC, with the exception of the DB-TUB silane (-) group. TUB increased SBS more than the other adhesives. Additional silane decreased SBS in the HF-TUB and TSC-CUQ groups, while increasing it in the TSC-TUB and DB-FMU groups (p<0.05).

The effect of repair protocols and chewing simulation on the microtensile bond strength of two resin matrix ceramics to composite resin

BACKGROUND

To assess the micro tensile bond strength (µTBS) of two resin matrix ceramic (RMC) blocks bonded to composite resin by using different repair protocols with and without chewing simulation (CS).

MATERIALS AND METHODS

Two resin matrix ceramic blocks (Vita Enamic and Lava Ultimate) were divided into 4 groups according to the surface treatments: Bur grinding (control), Bur grinding + silane, 9.5% HF acid etching, and 9.5% HF acid etching + silane. The single bond universal adhesive was applied on all specimens after the surface treatments according to the manufacturer's instructions, it was administered actively on the treated surface for 20 s and then light cured for 10 s, followed by incremental packing of composite resin to the treated surface. Each group was further divided into 2 subgroups (with/without chewing simulation for 500,000 cycles). A micro tensile bond strength test was performed for each group (n = 15). The effect of surface treatments on the materials was examined by using a scanning electron microscope (SEM). The micro tensile bond strength (MPa) data were analyzed with a three-way ANOVA, the independent t-test, and one-way ANOVA followed by the Tukey post-hoc test.

RESULTS

µTBS results were significantly higher for Lava Ultimate than Vita Enamic for all the surface treatment protocols with (p < 0.01). The chewing simulation significantly negatively affected the micro-tensile bond strength (p < 0.001). Bur grinding + saline exhibited the highest bond strength values for Lava Ultimate, both with and without chewing simulation. For Vita Enamic, bur grinding + saline and HF acid + saline showed significantly higher bond strength values compared to other surface treatments, both with and without chewing simulation (p ≤ 0.05).

CONCLUSION

Bur grinding + silane could be recommended as a durable repair protocol for indirect resin matrix ceramics blocks with composite resin material.

Effect of plasma surface treatment of three different CAD/CAM materials on the micro shear bond strength with resin cement (A comparative in vitro study)

Objectives

This study aimed to evaluate and compare the effect of plasma treatment versus conventional treatment on the micro shear bond strength (μSBS), surface roughness, and wettability of three different CAD/CAM materials.

Materials and methods

Sixty cylindrical specimens (5 mm diameter × 3 mm height) were prepared from three different CAD/CAM materials: Group A: Zirconia, Group B: Lithium disilicate, and Group C: Resin nano-ceramic. Each group was subdivided into two subgroups according to surface treatment used: Subgroup I: Conventional treatment, zirconia was sandblasted with Al₂O₃, while lithium disilicate and resin nano-ceramic were etched with hydrofluoric acid. Subgroup II: Plasma treatment, the surface of each material was treated with a plasma device (PiezoBrush® PZ3 Handheld Device, Relyon Plasma, Regensburg, Germany). G-Multi PRIMER was applied, then self-adhesive cement (G-CEM ONE) was applied using a split mold (1 mm diameter × 3 mm height), and μSBS was tested in a universal testing machine. The surface roughness was measured using a profilometer. Nine additional specimens of each material for wettability test using an optical tensiometer.

Statistical analysis

The data were analyzed using ANOVA and Bonferroni test at a level of significance of 0.05.

Results

The highest mean of μSBS was recorded by AII (27.3 MPa), while the lowest was recorded by AI (17.9 MPa). One-way ANOVA test revealed a significant difference among groups. Bonferroni test showed each two subgroups significant difference except subgroups AI, CI and BII, CII, where there was a non-significant difference. For all CAD/CAM materials, conventional treatment increased the surface roughness compared to plasma treatment, while the contact angle decreased after plasma treatment.

Conclusion

Plasma treatment increased the μSBS of resin cement to zirconia significantly while not significantly affecting the μSBS of resin nano-ceramic. Conventional treatment of lithium disilicate provided significantly higher μSBS than plasma treatment.

Bond Strength of Zirconia Ceramics to Dentin Using Two Resin Cements: Influence of Dentin Conditioning.. [DOI: 10.21203/rs.3.rs-3067702/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0]

Background Dentin adhesion has difficult challenge compared to enamel adhesion. The purpose of the current study was to assess the impact of different dentin conditioning methods and two different resin cements on bond strength of zirconia ceramics to dentin. Methods A total of 64 zirconia discs were fabricated using CAD/CAM technology according to the desired dimensions (8mm diameter ×3mm thickness). A total of 64molars mounted in plastic rings with acrylic resin were prepared by exposing flat coronal dentin surfaces by removing the occlusal enamel and superficial dentin. The prepared molars were divided into 4 main groups (n = 16) according to dentin surface treatment; Dentin left as cutted, treated with EDTA, treated with Polyacrylic Acid (PAA), treated with self-etch adhesive. Each main group was subdivided into 2 subgroups (n = 8) according to luting cement used. One of the subgroups, zirconia discs were bonded to conditioned dentin surface using adhesive resin cement (VITA ADIVA® F-CEM). The other subgroup was bonded using self-adhesive resin cement (Calibra®Universal). After bonding, all specimens were stored in water bath at 37⁰C for 6 months followed by 10.000 thermal cycles. After artificial aging, all bonded specimens underwent shear bond strength testing using universal testing machine. The data was parametric and normally distributed. Two-way ANOVA was used to test significant difference in shear stress between cements and between surface treatments followed by post hoc Tukey test for correction of p value resulted from multiple comparisons. P is significant if < 0.05 at confidence interval 95%. Results There was a significant difference in shear bond strength between surface treatments. The highest shear bond strength was reported with Self-etch adhesive, followed by PAA, then EDTA surface treatments, and the lowest shear bond strength was reported with as cutted dentin. Also,There was a significant difference between each two surface treatments except between PAA and EDTA for adhesive resin cement group. Conclusion Define dentin surface treatment with self etch adhesive is recommended before bonding zirconia restoration overall the conditioning materials, followed by PAA and EDTA. Specially with self-adhesive resin cement (Calibra universal cement).

Influence of mechanical and chemical pre-treatments on the repair of a hybrid ceramic

OBJECTIVES

This study aimed to investigate the influence of the respective mechanical and chemical pre-treatments on the composite repair of a CAD/CAM hybrid ceramic using a microtensile bond strength test (μTBS).

METHODS

15 CAD/CAM Blocks of Vita Enamic (VE) were randomly sectioned into three mechanical pre-treatments: (1.) Diamond bur (D), (2.) Airborne abrasion (A), (3.) Tribochemical silica coating (T) and subsequently five chemical pre-treatments: (1.) Clearfil SE Bond Bond (B; negative control), (2.) ESPE Sil (S), (3.) Clearfil Ceramic Primer Plus (CPP), (4.) Clearfil Repair (CR) and (5.) Scotchbond Universal (SCB). Per block, n = 20 specimens were sawn. Half of the specimens were randomly selected and subjected to an immediate bond strength test, while the other half was subjected to artificial aging for 6 months 180 days at 37 °C and subsequent thermocycling of 5000 cycles. A μTBS was performed and data (MPa) were compared in one-way and two-way ANOVA and Tukey's HSD. Paired-t-test was used for artificial aging (α = 0.05). Debonded specimens were analyzed of for failure modes with a stereomicroscope (SEM).

RESULTS

The results of one-way ANOVA for the fifteen fastening procedures after aging indicated significant differences according to SCB-A and CPP-T. Two-way ANOVA after aging observed inferior bond strength for SCB. No differences were observed for mechanical pre-treatments. Artificial aging showed a significant reduction in bond strength on most of the fastening procedures.

SIGNIFICANCE

SCB showed the lowest bond strength values besides B, S, CPP, and CR. MDP and silane are both suitable for the repair of VE.

Evaluation of surface characterization and mechanical features of resin-matrix ceramics before and after different surface treatments

STATEMENT OF PROBLEM

Surface treatments (STs) required for micromechanical interlocking can lead to alterations in the surface characterization and mechanical features of the resin-matrix ceramics (RMCs), which may jeopardize the long-term outcome of an indirect restoration. However, evidence on this issue is lacking.

PURPOSE

The purpose of this in vitro study was to assess the influence of different STs on the surface roughness (SR), water contact angle (WCA), and flexural strength (FS) of RMCs.

MATERIAL AND METHODS

Two hundred rectangular plates (12×14×1 mm) were prepared from 5 different RMC ingots, including a polymer-infiltrated ceramic network (Vita Enamic [VE]), 2 resin nanoceramics (Lava Ultimate [LU], Grandio Blocks [GB]), a flexible nanoparticle-filled resin (GC Cerasmart [GC]), and a reinforced composite resin (Brilliant Crios [BC]). Plates of each RMC group were further divided into 4 subgroups according to the ST applied: Control, no treatment (C); airborne-particle abrasion with aluminum oxide particles (APA); 2W- and 3W-Er,Cr:YSGG laser irradiations (LI^2W, LI^3W) (n=10 per ST). The SR (Ra) of each plate was recorded with a contact profilometer. WCAs (θ) of distilled water on the plates were determined by using the sessile-drop method. The FS (MPa) of each plate was measured with a universal testing machine. Data acquired for SR, WCA, and FS were statistically analyzed (α=.05). Weibull statistics were also conducted to determine the reliability of each material.

RESULTS

The 2-way ANOVA showed that SR, WCA, and FS values were significantly influenced not only by all tested variables but also by their interaction terms (P<.001). All STs significantly increased the SR values (P<.05). Maximum and minimum SR values were recorded in GC-LI^3W (7.06 ±0.16) and GC-C (0.07 ±0.02) groups. After STs, WCA values significantly diminished (P<.05). Maximum and minimum WCA values were recorded in LU-C (61.74 ±2.45) and VE-APA (40.38 ±1.56) groups. All STs significantly reduced the FS values (P<.05). The upper and lower FS bounds were 140.7 ±17.07 and 60.66 ±6.31, respectively, set by VG-C and GC-APA. Weibull distribution indicated that the untreated groups presented the highest m values. Among the treated groups, BC-LI^3W demonstrated superior reliability (m=14.04).

CONCLUSIONS

APA for LU, LI^2W for VG and BC, and LI^3W for GC and VE can be preferred. Although APA increased the SR and provided more wettable surfaces, it caused considerable loss of FS. Therefore, LI can be recommended as a safer ST for RMCs.

Effect of sandblasting and/or priming treatment on the shear bond strength of self-adhesive resin cement to CAD/CAM blocks

The aim of this study was to investigate the effect of two different priming agents and/or sandblasting on the shear bond strength of self-adhesive resin cement to the resin composite for core build-up to CAD/CAM blocks. A CAD/CAM ceramic block (GN I CERAMIC BLOCK, GC) and a CAD/CAM resin composite block (CERASMART 270, GC), a self-adhesive resin cement (G-CEM ONE, GC) and two different primers, i.e., a multipurpose primer (MP; G-Multi Primer, GC) and a ceramic primer (CP; Ceramic Primer II, GC), were examined. Five different surface treatments with priming and/or sandblasting and no surface treatment (control) were performed on the block. Disk specimens (6 mm in diameter and 4 mm in thickness) made from core composites were cemented to the blocks after the surface treatments. Then, the 24-h shear bond strength of the resin cement between the block and the resin composite core was determined (n = 15). Sandblasted specimens had greater bond strength than controls for both blocks (p < 0.05). Priming to both blocks significantly increased the bond strength of resin cement compared to that of controls (p < 0.05). Although Weibull moduli were not significantly changed among all surface treatments for both blocks, the strengths with 5% and 95% failure probability of sandblasted and/or primed blocks were estimated to be greater than those of controls. The combination of priming and sandblasting to the CAD/CAM composite and ceramic surface was effective in increasing the bond strength of the resin cement.

Micro-shear bond strengths of resin-matrix ceramics subjected to different surface conditioning strategies with or without coupling agent application

PURPOSE

This study aimed to assess the influence of various micromechanical surface conditioning (MSC) strategies with or without coupling agent (silane) application on the micro-shear bond strength (µSBS) of resin- matrix ceramics (RMCs).

MATERIALS AND METHODS

GC Cerasmart (GC), Lava Ultimate (LU), Vita Enamic (VE), Voco Grandio (VG), and Brilliant Crios (BC) were cut into 1.0-mm-thick slices (n = 32 per RMC) and separated into four groups according to the MSC strategy applied: control-no conditioning (C), air-borne particle abrasion with aluminum oxide particles (APA), 2W- and 3W-Er,Cr:YSGG group coding is missing. The specimens in each group were further separated into silane-applied and silane-free subgroups. Each specimen received two resin cement microtubules (n = 8 per subgroup). A shear force was applied to the adhesive interface through a universal test machine and µSBS values were measured. Data were statistically analyzed by using 3-way ANOVA and Tukey HSD test. Failure patterns were scrutinized under stereomicroscope.

RESULTS

RMC material type, MSC strategy, and silanization influenced the µSBS values (P<.05). In comparison to the control group, µSBS values increased after all other MSC strategies (P<.05) while the differences among these strategies were insignificant (P>.05). For control and APA, there were insignificant differences between RMCs (P>.05). The silanization decreased µSBS values of RMCs except for VE. Considerable declines were observed in GC and BC (P<.05).

CONCLUSION

MSC strategies can enhance bond strength values at the RMC - cement interface. However, the choice of MSC strategy is dependent on RMC material type and each RMC can require a dedicated way of conditioning.

Influence of Low-Pressure Plasma on the Surface Properties of CAD-CAM Leucite-Reinforced Feldspar and Resin Matrix Ceramics

The introduction of new ceramic materials for dental restorations is currently a reality; however, little information is available on their surface treatment for the bonding process. Furthermore, surface treatment with plasma on ceramic materials has been recently introduced, although not many studies are available. The aim of this study was to evaluate the surface properties of a leucite-reinforced feldspar ceramic (LIC) and resin matrix ceramic (RMC) after low-pressure plasma treatment. From each material, 48 discs were prepared and subject to surface treatment. The LIC group was treated by hydrofluoric acid (HF) (LIC-HF), plasma with oxygen (LIC-O2), and plasma with argon (LIC-Ar). The RMC group was treated by sandblasting with alumina (RMC-SB), plasma with oxygen (RMC-O2), and plasma with argon (RMC-Ar). The groups whose surfaces were not subjected to treatment were considered as the control group. Surface wettability and roughness was analyzed. The results showed significant differences among the treatments for both ceramics regarding wettability and roughness. Plasma treatments increased the wettability and had a very low effect on the roughness. Plasma treatments achieved similar values for both surface properties in each ceramic group with no differences between both treatments. Plasma treatment seems to be a promising alternative for ceramic surface treatments since it increased the surface energy of the ceramics analyzed and hardly affects the roughness. Further studies are necessary to evaluate the effect of plasma treatment on the bond strength of ceramics.

Effect of surface treatment of CAD/CAM resin composites on the shear bond strength of self-adhesive resin cement

This study examined the effects of sandblasting, hydrofluoric acid etching and priming on the shear bond strength of self-adhesive resin cement between seven different CAD/CAM resin composites and a resin composite core material at 24-h after cement mixing. Five surface treatments [control (C), sandblasting (S), priming (P), sandblasting with priming (SP), and 9% HF etching with priming (HFP)] were performed respectively for disc specimens of CAD/CAM blocks. There were no significant differences in bond strength among the C, S, and P, except for one block (p>0.05). SP showed a greater bond strength than S. Weibull moduli were not changed significantly among all treatments for all blocks, whereas the strengths with 5% and 95% failure probability of SP and HFP showed greater values than the others. The bond strengths of HFP were comparable to those of SP. Priming after sandblasting or HF etching could be effective to increase the bond strength of CAD/CAM blocks.

Effect of Pressure and Particle Size During Aluminum Oxide Air Abrasion on the Flexural Strength of Disperse-Filled Composite and Polymer-Infiltrated Ceramic Network Materials

Esthetic dental computer-aided design/computer-aided manufacturing (CAD/CAM) polymers such as disperse-filled composites (DFC) and polymer-infiltrated ceramic networks (PICN) should be subjected to surface treatment before bonding. However, such treatment can lead to defect formation and a decrease in strength. Therefore, in this study, we compared the flexural strengths of DFC and PICN materials air-abraded with alumina particles of different sizes at different pressures. In addition to Weibull analysis, the samples (untreated and treated) were characterized by scanning electron microscopy and atomic force microscopy. Both DFC and PICN exhibited the lowest flexural strength at large particle sizes and high pressures. Therefore, we optimized the air abrasion parameters to maintain the flexural strength and significantly increase surface roughness. In the case of DFC, the optimal particle size and pressure conditions were 50 µm at 2 bar and 110 µm at 1 bar, while for PICN, the best performance was obtained using Al₂O₃ particles with a size of 50 µm at 1 bar. This study reveals that optimization of the surface treatment process is crucial in the fabrication of high-performance clinical materials for dental restorations.

Bonding to industrial indirect composite blocks: A systematic review and meta-analysis

OBJECTIVE

The aim of this systematic review and meta-analysis was to evaluate the effect of surface conditioning methods on the bond strength of industrial indirect composite blocks (ICs).

METHODS

Based on the PICOS strategy, the Medline via PubMed, Embase and Web of Science (ISI - Web of Knowledge) electronic databases were searched for peer-reviewed articles in both English and Chinese, with no publication year limit. In vitro studies evaluating the effects of surface conditioning on the bond strength of ICs were selected. The meta-analysis was conducted to calculate the mean difference between surface-conditioned ICs and unconditioned controls. Subgroup analysis was performed to evaluate the different surface conditioning methods, separately for polymer-infiltrated ceramic network (PICN) material and the ICs with dispersed fillers (ICDFs). Meta-analyses were performed with a random-effects model at a significance level of 0.05.

RESULTS AND SIGNIFICANCE

From 802 relevant studies, 25 were selected for full-text analysis. Nineteen studies were eligible for inclusion in this systematic review, whereas 9 studies were included in the meta-analysis. A manual search of the principal periodicals specific to the area resulted in no additional articles. The meta-analysis indicated a significant difference in bond strength between the surface-conditioned ICs and controls under both non-aged and aged conditions. The combination of mechanical and chemical conditioning yielded the highest bond strength of ICs. This meta-analysis suggests that chemical etching followed by a universal primer and alumina air abrasion followed by a silane coupling agent could be considered the best strategy for optimizing the bond strength of PICN materials and ICDFs under aged conditions, respectively.