Influence of Composite Type, Surface Treatment, and Thermocycling Aging on the Shear Bond Strength of Repaired Composite Resins.

To evaluate the shear bond strength (SBS) between zirconia and veneering ceramic following different surface treatments of zirconia. The efficacy of an experimental zirconia coating to improve the bond strength was also evaluated. Zirconia strips were fabricated and were divided into four groups as per their surface treatment: polished (control), airborne-particle abrasion, laser irradiation, and application of the experimental coating. The surface roughness and the residual monoclinic content were evaluated before and after the respective surface treatments. A scanning electron microscope (SEM) analysis of the experimental surfaces was performed. All specimens were subjected to shear force in a universal testing machine. The SBS values were analyzed with one-way ANOVA followed by Bonferroni post hoc for groupwise comparisons. The fractured specimens were examined to observe the failure mode. The SBS (29.17 MPa) and roughness values (0.80) of the experimental coating group were the highest among the groups. The residual monoclinic content was minimal (0.32) when compared to the remaining test groups. SEM analysis revealed a homogenous surface well adhered to an undamaged zirconia base. The other test groups showed destruction of the zirconia surface. The analysis of failure following bond strength testing showed entirely cohesive failures in the veneering ceramic in all study groups. The experimental zirconia surface coating is a simple technique to increase the microroughness of the zirconia surface, and thereby improve the SBS to the veneering ceramic. It results in the least monoclinic content and produces no structural damage to the zirconia substructure.

Objective The aim was to investigate the effect of different interfacial surface treatments on the shear bond strength (SBS) between a short fiber-reinforced flowable composite (SFRC) and a particulate-filled flowable composite (PFC). In addition, SBS between two successive layers of similar materials was evaluated. Materials and methods One-hundred and forty-four specimens were prepared having either SFRC (everX Flow) as a substructure composite and PFC (G-aenial Flo X) as a surface composite or having one of the two materials as both substructure and surface layer. Eight groups of specimens were created (n = 18/per group) according to the interfacial surface protocol used. Group 1: no treatment; Group 2: ethanol one wipe; Group 3: ethanol three wipes; Group 4: phosphoric acid etching + bonding agent; Group 5: hydrofluoric acid etching + bonding agent; and Group 6: grinding + phosphoric acid etching. Group 7: only PFC layers and Group 8 (control) only SFRC layers without any surface treatment. After one-day storage (37 °C), SBS between surface and substructure composite layers was measured in a universal testing machine, and failure modes were visually analyzed. SEM was used to examine the bonding surface of the SFRC composite after surface treatment. SBS values were statistically analyzed with a one-way analysis of variance (ANOVA) followed by the Tukey HSD test (α = .05). Results The SBS between successive SFRC layers (Group 8) was statistically (p < .05) the highest (43.7 MPa) among tested groups. Surface roughening by grinding followed by phosphoric acid etching (Group 6) resulted in a higher SBS (28.8 MPa) than the remaining surface treatments. Conclusion Flowable composite with glass fibers (everX Flow) showed higher interlayer SBS compared to PFC flowable composite. Interfacial surface roughness increases the bonding of PFC to the substructure of SFRC.

BackgroundThe provisional 3D-printed methacrylate resin is progressively used due to its superior accuracy and durability compared to traditionally fabricated provisional restorations. However, chairside modifications remain necessary to enhance marginal adaptation, esthetics, and functionality. This study aimed to evaluate the effect of surface treatments and repair materials on shear bond strength (SBS) of aged provisional 3D-printed methacrylate resin.MethodsA total of 120 specimens (20 mm in diameter and 15 mm in height) were designed, printed using a DLP resin-based 3D printer, and aged by thermocycling for 1,500 cycles. Specimens (n = 10) were divided into four groups based on surface treatments: no surface treatment (negative control, NC), airborne particle abrasion (Al2O3), universal adhesive application (Adh), and airborne particle abrasion followed by the application of universal adhesive (Al2O3/Adh). Then, specimens were bonded using one of three repair materials: polymethyl methacrylate (PMMA), bis-acryl composite, and flowable composite. After 24 h, SBS was tested using a universal testing machine at a crosshead speed of 0.5 mm/min. Failure modes were examined using a stereomicroscope (20× magnification). The data were analyzed using the Kruskal-Wallis test, followed by Dunn’s test with a Bonferroni correction for multiple comparisons (p < 0.05).ResultsFlowable composite exhibited the highest SBS when aged provisional 3D-printed methacrylate resin was treated with Al2O3/Adh, Al2O3, and Adh, respectively, with no significant difference among these groups (p > 0.05). The lowest SBS was observed in NC, regardless of repair materials. Failure mode analysis was predominantly adhesive failure in the NC group, whereas cohesive and mixed failures were more common in the groups treated with Al2O3, Adh, and Al2O3/Adh, which were associated with improved bond strength.ConclusionTo achieve the optimal SBS between aged provisional 3D-printed methacrylate resin and repair/reline materials, surface preparation with Al₂O₃/Adh, Al₂O₃, or Adh followed by flowable composite is recommended.Clinical significanceIn clinical settings where airborne particle abrasion is unavailable or impractical, applying universal adhesive followed by flowable composite provides reliable bond strength to aged 3D-printed methacrylate resin. However, omitting surface treatment entirely is not recommended due to the significantly reduced bond strength.

The purpose of the present in vitro study was to evaluate the effects of nutritional habits (various liquids) on the color change and early repair bond strength of a leucite-based ceramic repaired with different contents of nanohybrid composite resins currently used by the clinicians. Ninety-six IPS-Empress CAD ceramic samples were obtained with low-speed diamond saw. For all samples same repair method was performed. Samples were divided into groups according to four nanohybrid composite resins used as a repair material: Tetric-N-Ceram Bulk Fill, Filtek Z550, Clearfil-Majesty Esthetic, Bisco-Aelite Aesthetic Enamel (n = 24). Composite resins were applied on ceramic surface and polymerized (40 sec). After waiting for 24 h, samples were divided into three subgroups according to liquid types: pomegranate-flavored mineral water, salad dressing, and distilled water (n = 8). Before and after immersion the samples in the various liquids, color measurements were calculated (24 h). Then, shear bond strength was tested with an universal testing machine.For the statistical analyses two-way ANOVA, Tukey HSD, Spearman's correlation tests were used at a significance of p ≤ 0.05. Nanohybrid composites, liquids (p ≤ 0.001); correlation between nanohybrid composites and liquids (p ≤ 0.006) had statistically significant impacts on the color change values. Nanohybrid composites (p ≤ 0.017) and correlation between nanohybrid composites and liquids (p ≤ 0.004) had statistically significant impacts on the shear bond strength values. There was not any statistically significant correlation between color change and shear bond strength (p > 0.05). When a composite resin is selected as a repair material, nutritional habits of the patient should be taken into consideration. Although hydrophilic monomer type of a composite material is a more predominant factor associated with color change, filler weight has the same predominant effect on shear-bond strength.

To assess how various surface treatment methods affect the repair shear bond strength (SBS) of flowable single-shade bulk-fill composite resins. 200 composite discs were fabricated using a nanohybrid composite (GrandioSo, VOCO) to simulate aged restorations. All specimens underwent 5,000 thermal cycles to mimic oral aging. Five different surface treatment approaches were tested: no treatment (control), diamond bur abrasion, phosphoric acid etching, Er,Cr:YSGG laser irradiation, and silane application. After treatment, three flowable single-shade bulk-fill composites: Omnichroma Flow Bulk (Tokuyama Dental), SimpliShade Bulk Fill Flow (Kerr), and Charisma Bulk Flow ONE (Kulzer) were bonded onto the aged surfaces using a universal adhesive (Tokuyama Universal Bond). SBS was measured with a universal testing machine, and failure modes were examined under a stereomicroscope. Statistical analyses were conducted with robust ANOVA and chi-square tests (α= 0.05). Both resin composite type and the surface treatment protocol, as well as their interaction, had significant effects on SBS values (P< 0.001). Among the tested groups, the highest SBS was recorded for GrandioSo combined with silane treatment (23.85 MPa), while the lowest was found for Charisma Bulk Flow ONE after acid etching (10.8 MPa). Silane application resulted in significantly greater SBS compared to other treatments (P< 0.001). Adhesive failures were most prevalent in the acid and control groups, whereas laser and silane groups displayed more cohesive and mixed failures. Effective surface conditioning is essential for durable and predictable composite repairs. Silane application and Er,Cr:YSGG laser irradiation significantly improved the repair bond strength of flowable single-shade bulk-fill composites, whereas phosphoric acid etching alone was insufficient.

Improving the retention of zirconia-based ceramics is desirable in order to avoid the failure of crowns and fixed partial dentures .This can be achieved by creating micromechanical retention using surface treatments. Therefore, it becomes necessary to constantly compare and re-evaluate the influence of different surface treatment methods on the bond strength . To evaluate the effect of four different surface treatments on shear bond strength between zirconia surface and resin cements. Observational study. Twenty five zirconia plate samples were prepared based on ISO standards and were divided into five groups and each group was subjected to following five different surface treatments : no treatment, sandblasting with 110 μm alumina, sandblasting with 250 μm alumina, acid etching with 9.6% hydrofluoric acid and laser radiation on the surface. All the samples were surface disinfected and were embedded in blocks of autopolymerising resin to check shear bond strength on the universal testing machine. Statistical analysis used-data was analyzed using one-way ANOVA and a Post Hoc Bonferroni test. Analysis of the data showed that the highest shear bond strength values were obtained with laser treatment (18.120 ± 0.8159 Mpa). The lowest values were obtained with control group (9.166 ± 0.569 Mpa). Laser treatment increased the shear bond strength values significantly (p<0.05). Surface treatments increased the bond strength between zirconia and resin cement and carbon dioxide laser could be an effective surface treatment for increasing bond strength.

The oral environment significantly influences the esthetic appearance of CAD/CAM provisional restorative materials. Therefore, a veneering layer is required. Bonding veneering resin composites to these materials presents challenges, particularly under conditions of thermal aging. This study evaluated the impact of various surface treatments and thermal aging on the bond strength between veneering resin and CAD/CAM provisional materials. Fifty disk-shaped specimens of each CAD/CAM material (CAD-Temp, Everest C-Temp, and PEEK), measuring 10 mm in diameter and 3 mm in height, were fabricated. After being ultrasonically cleaned, specimens were embedded in acrylic resin blocks, leaving one surface exposed for surface treatments. Specimens were assigned to five groups at random. Group C: no surface treatments applied; DB: mechanically roughened with a diamond bur; DB + TC: DB group subjected to 5000 cycles of thermocycling; SB: treated with aluminum oxide airborne abrasion; SB + TC: SB group subjected to 5000 cycles of thermocycling. After the surface treatments, the primer and resin veneering composite were applied to the specimens. The shear bond strength (SBS) was calculated using a universal testing machine and the mode of failure was evaluated with an optical stereomicroscope with 40× magnification. Scanning electron microscopy evaluation was conducted to examine the surface topography of the materials’ surfaces after surface treatments. C-Temp in the SB group exhibited the highest SBS values (20.38 ± 1.04 MPa), while CAD-Temp in the C group showed the lowest values (4.60 ± 0.54 MPa). PEEK recorded significantly higher SBS values in DB + TC and SB + TC groups (9.26 ± 1.07 and 12.92 ± 0.97 MPa, respectively) compared to CAD-Temp in DB + TC and SB + TC groups (6.04 ± 0.76 and 8.82 ± 0.86 MPa, respectively). C-Temp exhibited higher SBS without surface treatment (13.11± 0.55 MPa), whereas PEEK showed higher SBS after diamond bur roughening and air particle abrasion (10.87 ± 1.02 MPa, and 14.37 ± 0.98 MPa, respectively). The thermocycling significantly reduced SBS values for C-Temp in the DB + TC and SB + TC groups (11.18 ± 0.92, 15.56 ± 0.87 MPa, respectively) and CAD-Temp in the DB + TC and SB + TC (6.04 ± 0.76 MPa and 8.82 ± 0.86 MPa, respectively). Conversely, the thermocycling had no significant effect on SBS values for PEEK material in the air particle abrasion group (12.92 ± 0.97 MPa).

The bonding of resin cement to ceramic materials plays an important role in dentistry. The purpose of this study is to evaluate the effects of various surface treatments on the shear bond strength (SBS) of zirconia ceramic and metal alloy. A total of 60 specimens were prepared from Y-TZP ceramic and metal alloy. The specimens were divided into three subgroups (n = 10) that received different surface treatments for each material. An Er:YAG laser (ER), a femtosecond laser (FS), and air-borne particle abrasion (A) were employed as surface treatments. One specimen from each group was analyzed using a scanning electron microscope (SEM) at 500 x magnification after surface treatments. The self-adhesive resin cement was then bonded to the treated surfaces using a Teflon mold. The specimens were thermocycled for 5,000 cycles at 5–55 °C, and then the SBS test was performed. Kruskal–Wallis and Mann–Whitney U tests were used to determine the differences between the groups (p = 0.05), and failure modes were evaluated for each specimen. Statistical analyses revealed significant differences between the surface treatment methods. The mean SBS values of the air-borne particle-abraded groups were higher than those of the other groups. The femtosecond-irradiated groups of each material showed significantly higher SBS values than the Er:YAG-irradiated groups (p < 0.05). Within the limitations of this study, air-borne particle abrasion and the femtosecond laser were more effective than Er:YAG laser treatment.

The purpose of this in vitro study was to investigate the effects of various surface treatment methods on the shear bond strength of self-adhesive resin cement to polymer-infiltrated materials. One hundred twenty-eight polymer-infiltrated specimens (n = 32) for four different computer aided design-computer-aided manufacturing (CAD-CAM) materials, polyether ether ketone (PEEK) (PE), polyether ketone ketone (PEKK) (PK), composite resin nanoceramic (Cerasmart) (CS), and polymer-infiltrated ceramic network (PICN) (VITA ENAMIC) (VE) were milled from CAD-CAM blocks. They were divided into two groups (n = 16) in terms of surface treatments: airborne-particle abraded (AA) or silica-coated (SC) and two subgroups (n = 8) according to adhesive application or no adhesive. The surface roughness, contact angle, and shear bond strength (SBS) values of specimens were measured. Data were analyzed with Shapiro-Wilk test, the generalized linear models' method, and Bonferroni corrected t test (α ˂ 0.05). No statistically significant differences were found between the groups in terms of surface roughness and SBS values (P > 0.05). A statistically significant effect of the main adhesive interaction on the bond strength was found independent of the material and surface treatments (P < 0.001). While the average bond strength of the non-adhesive was 4.9MPa, the average of the adhesive applied was 9.1MPa. On the other hand, there is a statistically significant difference between the means of the contact angle values (P ˂ 0.001). While the highest mean contact angle value was 117.1 ± 14.8° obtained from the non-adhesive PK in the AA group, the lowest mean contact angle value 22.6 ± 4.3° was obtained from the VE without adhesive in the SC group. Roughness and SBS values were similar between groups after surface treatments. Adhesive application increased the SBS values. Surface treatments were found to have an effect on the contact angle. Since the AA and SC surface treatments used in the study show similar bond strength values, the Cojet system, which is more practical and easier to use, can be preferred as an alternative to AA after restoration production with CAD-CAM as a chairside.

This study aimed to comparatively evaluate the effects of various surface treatment protocols on the shear bond strength (SBS) between heat-polymerized polymethyl methacrylate (PMMA) and different CAD/CAM framework materials, including cobalt-chromium (Co-Cr) alloys, ceramic particle-reinforced polyetheretherketone (PEEK), and glass fiber-reinforced composite resin (FRC). A total of 135 disc-shaped specimens were prepared from Co-Cr, PEEK, and FRC materials. Surface treatments specific to each material, including airborne-particle abrasion, sulfuric acid etching, laser irradiation, plasma activation, and primer application, were applied. PMMA cylinders were polymerized onto the treated surfaces, and all specimens were subjected to 30,000 thermal cycles. SBS values were measured using a universal testing machine, and the failure modes were classified. The normality of data distribution was assessed using the Kolmogorov-Smirnov test, and the homogeneity of variances was evaluated using Levene's test. Group comparisons were performed using the Kruskal-Wallis test, and Dunn's post hoc test with Bonferroni correction was applied in cases where significant differences were detected (α = 0.05). The highest SBS values (~27-28 MPa) were obtained in the Co-Cr group and in the PEEK groups treated with sulfuric acid and primer. In contrast, the PEEK group with additional laser treatment exhibited a lower SBS value. The untreated PEEK group showed significantly lower SBS (~3.9 MPa) compared to all other groups. The Trinia groups demonstrated intermediate SBS values (16.5-17.4 MPa), which exceeded the clinically acceptable threshold of 10 MPa. SEM observations revealed material- and protocol-specific surface responses; plasma-treated specimens maintained topographic integrity, whereas laser-induced surfaces showed localized degradation, particularly following dual-step protocols. Fracture mode analysis indicated that higher SBS values were associated with cohesive or mixed failures. SEM observations suggested that plasma treatment preserved surface morphology more effectively than laser treatment. This study highlights the importance of selecting material-specific surface treatments to optimize bonding between CAD/CAM frameworks and PMMA. Sulfuric acid and primer provided strong adhesion for PEEK, while the addition of laser or plasma offered no further benefit, making such steps potentially unnecessary. Trinia frameworks also showed acceptable performance with conventional treatments. These findings reinforce that simplified conditioning protocols may be clinically sufficient, and indicate that FRC materials like Trinia should be more fully considered for their broader clinical potential in modern CAD/CAM-based prosthetic planning.

Statement of the Problem: Delamination of zirconia-veneered restoration is considered to be a very common failure in clinical practice. Therefore, using a chair side intra-oral repair option may be a simple alternative method to the total replacement of the restoration and may provide a clinically-acceptable and reliable immediate solution. Aim of the Study: This study evaluated the shear bond strength of two different repairing systems (CoJet and Ceramic repair N) of zirconia-based restorations and evaluated the effect of high and low sandblasting pressure on the shear bond strength between zirconia and composite resin. Materials and Methods: Thirty zirconia specimens were divided into two main groups according to the repairing systems: Group CJ: CoJetTM repairing system [chairside silica coating with 30 µm SiO2 + silanization + adhesive] (3M ESPE) (15 specimens). Group CR: Ceramic Repair N system (Ivoclar Vivadent) [grinding with diamond stone + Monobond N universal primer adhesive] (15 specimens). Each group was further sub-divided into three sub-groups according to the surface treatment methods: Sub-groups (CJS 3, 2,1): CoJet Sandblasting at pressure 3,2,1 bar, Sub-group (CRG): Ceramic Repair Grinding with diamond stone and Sub-groups (CRS 2,1): Ceramic Repair Sandblasting with CoJet sand at pressure 2 and1 bar. Tetric N- ceram composite resin was polymerized on each conditioned specimen. The shear bond strength was tested using a universal testing machine, and fracture sites were examined with SEM. The data of bond strengths were statistically analyzed with two-way ANOVA. Results: No statistically significant differences in the mean shear bond strength values between Cojet Group (11.31± 0.71 MPa) and Ceramic Repair-N Group (11.02± 0.81 MPa). There were no statistically significant differences in the mean shear bond strength values between 1 bar treated sub-group (11.13± 1.4 MPa), 2 bar treated sub-group (11.23± 1.5 MPa), grinding sub-group and 3 bar (control) sub-group (11.12±1.8MPa), (P>0.05). Conclusion: Surface treatment of low pressure abrasion protocol or grinding following with Monobond N universal primer gave the similar shear bond strength values of the high pressure abrasion protocol.

Objective. This study compared the sensitivity of three shear test methods for measuring the shear bond strength (SBS) of resin cement to zirconia ceramic and evaluated the effects of surface treatment methods on the bonding. Materials and methods. Polished zirconia ceramic (Cercon® base, DeguDent) discs were randomly divided into four surface treatment groups: no treatment (C), airborne-particle abrasion (A), conditioning with Alloy primer (Kuraray Medical Co.) (P) and conditioning with Alloy primer after airborne-particle abrasion (AP). The bond strengths of the resin cement (Multilink N, Ivoclar Vivadent) to the zirconia specimens of each surface treatment group were determined by three SBS test methods: the conventional SBS test with direct filling of the mold (Ø 4 mm × 3 mm) with resin cement (Method 1), the conventional SBS test with cementation of composite cylinders (Ø 4 mm × 3 mm) using resin cement (Method 2) and the microshear bond strength (μSBS) test with cementation of composite cylinders (Ø 0.8 mm × 1 mm) using resin cement (Method 3). Results. Both the test method and the surface treatment significantly influenced the SBS values. In Method 3, as the SBS values increased, the coefficients of variation decreased and the Weibull parameters increased. The AP groups showed the highest SBS in all of the test methods. Only in Method 3 did the P group show a higher SBS than the A group. Conclusions. The μSBS test was more sensitive to differentiating the effects of surface treatment methods than the conventional SBS tests. Primer conditioning was a stronger contributing factor for the resin bond to zirconia ceramic than was airborne-particle abrasion.

Surface roughness and bond strengths of glass-infiltrated alumina-ceramics prepared using various surface treatments

This study evaluated the impact of different surface treatments - cold atmospheric plasma (CAP), airborne particle abrasion (APA), hydrofluoric acid (HF), and their combinations - on the bond strength of two zirconia types (3Y-TZP, 5YSZ) to dentin using self-adhesive resin cement, with or without primer. Two hundred zirconia and dentin specimens underwent surface treatment, cementation, thermocyclic aging, and shear bond strength (SBS) testing. Results showed APA and CAP significantly enhanced SBS (P < 0.001), while HF had no effect. Combined treatments (APA+CAP, CAP+HF) slightly reduced SBS. Primer application improved SBS across all groups. APA or CAP with a 10-MDP primer achieved the highest SBS values. CAP is a viable alternative to APA, though APA remains cost effective. HF is not recommended for surface treatment of zirconia. CAP exhibited a slightly higher, yet statistically comparable, SBS between zirconia and dentin when compared with APA. Nonetheless, APA may still represent the simplest and most cost-effective technique available to date. The combination of APA and CAP might not be recommended, as it showed a slight reduction in SBS of the tested specimens and inefficiency in terms of time and energy. Hydrofluoric acid showed no impact on SBS when combined with CAP. Both 3Y-TZP and 5YSZ can provide adequate clinical bond strength with the proper surface treatment and adhesive protocol.

Effect of surface treatment on roughness and bond strength of a heat-pressed ceramic