Effect Of Various Surface Treatments Research Articles

Repair Bond Strength of Composite Resin to Dental Ceramic Using Various Surface Treatments: An In Vitro Study

Abstract Aim: This research aims to evaluate and compare the effect of various surface treatments and adhesive types on the bond strength between composite resin and two types of ceramic materials. Materials and Methods: A total of 98 disk-shaped of 10 mm diameter and 4 mm thickness were fabricated for each of the zirconia (H. C. Starck) and lithium disilicate (IPS E-Max computer-aided design), which were implanted individually in the acrylic resin mold leaving one surface exposed. The disks in each group were sub-divided according to the surface treatments into seven groups (n = 14): [hydrofluoric acid (HF, 9.5%), air abrasion, bur, laser, HF + bur, HF + air abrasion, HF + laser]. Each sub-group was further divided into two groups (n = 7) according to the type of adhesive used for the repairing procedure [G-Premio Bond universal adhesive group and intraoral repair kit (BISCO) group]. Each adhesive was applied depending on manufacturer instructions and, then, the composite cylinder (4 mm in diameter and 4 mm in height) was built on the pre-determined treated ceramic surface area by the addition of rubber mold. Then the samples were stored in distal water for 24 h. After that, all groups were submitted to a shear bond test using an Instron testing machine (TSTM 02500; Elista Ltd., Istanbul, Turkey) at 0.5 mm/min a crosshead speed. The data were analyzed by three-way analysis of variance and Tukey post hoc test at (P ≤ 0.05). Results: The HF + air abrasion groups registered the higher bond strength but with no statistically significant difference from groups of HF + bur. While the laser groups showed the lowest mean bond strength. Generally, E-Max registered significantly higher bond strength in comparison to zirconia. Finally, the BISCO repair system registered a significantly higher bond strength value in comparison to G-Premio. Conclusion: Combined surface treatment of HF + air abrasion with an intraoral repair kit can provide a promising method for repairing cracked ceramic restorations. However, repairing lithium disilicate is more predictable and successful than zirconia.

Investigations on structure and properties of poly (3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) reinforced by diss fibers: Effect of various surface treatments

The paper reports some experimental results on the effect of different chemical modifications of Diss fibers on the properties of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) biocomposites involving alkaline, combined alkaline/peroxide and combined alkaline/silane treatments. The biocomposite samples loaded at 20 wt% were prepared by melt compounding. Scanning Electron Microscopy (SEM) showed a better fiber-matrix interaction between Diss fiber and matrix after surface fiber treatment. Differential Scanning Calorimetry (DSC) and X-ray Diffraction (XRD) results indicated an increase in crystallinity index of the biocomposites. In addition, the incorporation of Diss fibers treated with alkali-silane resulted in an improvement in Heat Deflection Temperature (HDT) and shore D hardness from 141.1 °C and 75.1–145.7°C and 86.2, respectively, in comparison with the neat matrix. This also agreed with the flexural properties results, which showed a significant increase in flexural modulus by almost 30 % compared to the neat PHBV. The same trend was observed for water absorption. Overall, combined alkali-silane treatment was found to be most efficient surface treatment method to develop strong interfacial adhesion between PHBV and Diss fiber, increasing the scope of application in manufacturing of light weight green composites.

Effect of Various Surface Treatments of Zirconia on its Adhesive Properties to Dentin: An In Vitro Study.

To assess the effectiveness of various surface treatments and adhesives on the bond strength of zirconia-based ceramic to dentin. Eighty samples of zirconia were subjected to the four-surface treatment protocols (sandblasting, 48% hydrofluoric acid (HF), 48% hydrofluoric acid + 70% nitric acid (HNO3) and no treatment (control) following which the samples from each group were subdivided into two subgroups (n = 10) based on the resin cement employed for cementation (RelyX U200 and G-Cem Linkforce). The bonded specimens were subjected to shear stress to measure the bond strength using Universal testing machine. To test the difference in bond strength among the eight study groups, the Kruskal-Wallis ANOVA test was applied and for comparison between cements in each group, Mann-Whitney U test was applied. The highest bond strength values were observed for 48% HF group cemented with G-Cem Linkforce resin cement (16.220 ± 1.574) and lowest for control group-RelyX (4.954 ± 0.972). G-Cem cement showed higher bond strength than RelyX for all surface treatments except 48% HF + 70% nitric acid. It can be inferred that 48% HF can etch zirconia and generate a porous structure that proves to be beneficial for bonding. The increasing demand for esthetics has led to the replacement of metal-ceramic materials with zirconia-based ceramics. However, the chemical inertness of zirconia to various conventional surface treating agents has continuously challenged researchers to discover a new surface treatment protocol that could enhance the bond strength of zirconia. How to cite this article: Yenamandra MS, Joseph A, Singh P, et al. Effect of Various Surface Treatments of Zirconia on its Adhesive Properties to Dentin: An In Vitro Study. J Contemp Dent Pract 2024;25(3):226-230.

Evaluation of the Impact of Different Surface Treatments on Implant Surface: An In Vitro Study.

The current study was conducted to assess the effects of various surface treatments on the implant surface. A total of 45 dental implants measuring 16 mm in length and 5 mm in diameter were used, along with the appropriate abutments. Depending on the surface treatment used, the samples were randomly split into three groups, with 15 implants in each group: Group 1: Control, Group 2: UV light-treated, Group 3: Sandblasted and acid-etched (SLA)-treated. After surface treatment, a scanning electron microscope (SEM) was used to assess the test samples' surface properties. All sample images were captured using a 3000× magnification. After all three groups' surfaces were treated, the surface roughness was measured using a digital optical profilometer with a stylus speed of 0.5 mm/s that was connected to computer software. The maximum surface roughness was found in the group treated with SLA (0.714 ± 0.12), followed by the group treated with UV light (0.692 ± 0.09) and the control group (0.516 ± 0.12). There was a significant difference found between different surface treatment methods. The present study concluded that the group that received the SLA treatment had the highest surface roughness when compared to the UV light and control groups.

Effect of various surface treatments on relining bond strength of CAD-CAM denture base materials.

The aim of this study was to analyze the impact of various surface treatments and production methods on the shear bond strength (SBS) between reline material and denture base resins. One-hundred-twenty specimens were produced using conventional heat-polymerization, subtractive, and additive techniques. Each group consisted of 40 specimens. The specimens were divided into four subgroups, each with 10 samples, for surface treatments. These subgroups were: (1) Control-only monomer application, (2) 50 μm airborne-particle abrasion, (3) 110 μm airborne-particle abrasion, and (4) Roughening with tungsten carbide bur. Representative specimens from each subgroup were examined under SEM. Then, auto-polymerized resin was condensed in the center of the specimens. Specimens were subjected to thermal aging (5000 cycles at 5-55°C). The SBS test was conducted and failure loads were recorded. The data were evaluated by two-way ANOVA and Tukey pairwise multiple comparisons method (p < 0.05). The additively produced group showed significantly lower SBS than conventional and subtractive groups (p < 0.001), with no significant differences between the subtractive and conventional groups. Specimens that underwent monomer application only showed the lowest SBS among surface treatments, while 50 μm airborne-particle abrasion showed the highest SBS. Based on the partial eta-squared analysis results, the surface treatment mainly impacted SBS. Among the surface treatment methods, treating denture bases with 50 μm airborne-particle abrasion is more effective for maintaining adhesion, especially in the additive technique.

The Effect of Various Surface Treatments and Materials on the Bond Strength in the Repair of Glass Hybrid Restorative Material

The Effect of Various Surface Treatments and Materials on the Bond Strength in the Repair of Glass Hybrid Restorative Material

A Critical Review of Anti-Corrosion Chemical Surface Treatment of Aluminum Alloys Used for Sports Equipment

Aluminum alloys with low-weight property are promising structure materials for sports equipment. Alloying element-rich second-phase particles create the risk of localized corrosion and result in failure of sports equipment. Chromate conversion coatings as conventional and successful surface treatments were employed to provide a thin but compact film against corrosion. However, chromate species were toxic and carcinogenic for human beings and this process has been highly restricted. In this sense, alternative processes such as trivalent chromium conversion coating with low environmental risk require better corrosion-resistant performance compared to chromate conversion coating. In addition, the closed-loop system of the chromate electroplating process has been used in Europe and the United States. This is also a sustainable process for surface treatment of aluminum alloys applied in sports equipment. The present paper aims to summarize the methods and types of different aluminum alloy surface treatments and compiles the effects of various surface treatments on the corrosion resistance of aluminum alloys. The eco-friendly application of aluminum alloys in the field of sports equipment may be facilitated in the future.

A comparative study of the effect of various surface treatments on the fracture behavior of aluminum adhesive joints under mode I loading

This study investigates the effect of different surface treatments on the fracture behavior of epoxy-aluminum joints under mode-I loading. Six surface treatments including degreasing, abrasion with varying grit sizes, alkaline etching, acid etching, a combination of alkaline and acid etching, and a combination of abrasion and acid etching were applied to aluminum surfaces before bonding. Surface morphology, roughness parameters, total surface free energy, contact angle, and elemental composition were analyzed. Results showed that the ultimate fracture load and fracture energy initially increased and then decreased with increasing surface roughness. The most effective treatments were found to be acidic etching in combination with alkaline etching and abrasion due to their synergetic effects. These treatments removed the natural oxide layer and created a porous oxide layer, enhancing surface roughness, increasing adhesive-substrate contact areas, and providing more sites for mechanical interlocking. Compared to the degreased specimens, significant improvements were observed, including a 40% and 31% increase in maximum fracture load, a 74% and 53% increase in initiation fracture energy, and a 65% and 47% increase in propagation fracture energy, respectively. Etching treatments demonstrated superior effects on the fracture behavior of aluminum adhesive joints compared to abrasion methods, leading to cohesive failure after etching treatments.

Effect of Various Surface Treatments on the Push-Out Bond Strength of Fiber Posts to Root Dentin.

Background This study aimed to evaluate the effect of various surface treatments on the push-out bond strength of fiber posts to root dentin. Methodology A total of 96 single-rooted premolars were decoronated and obturated and post spaces were prepared for 9 mm. The canals were irrigated with 17% ethylenediaminetetraacetic acid followed by distilled water. The samples were divided into the two following groups based on the type of fiber posts used: Group I - glass fiber post (Reforpost size 1) and Group II: quartz fiber post (Quartzix Added Posts number 1). Further, each group was divided into four subgroups based on the surface treatments (A: no treatment (control); B: silanization; C: 4% titanium tetrafluoride (four minutes) followed by silanization; D: sandblasting followed by silanization). After surface treatments, posts were cemented using self-adhesive resin cement (RelyX U200). Three 2 mm thick slices were obtained and push-out tests were done. Failure modes were analyzed under a stereomicroscope. The surface morphology of the posts was analyzed with a scanning electron microscope. Data were analyzed using a one-way analysis of variance. Results Treating the posts with airborne particle abrasion (sandblasting) followed by silanization showed the highest bond strength. The coronal level of the root showed the highest bond strength compared to the middle and apical levels. Adhesive failures between the resin cement and dentin were found to be the highest. Conclusions Sandblasting followed by silanization produced the highest bond strength. The coronal level of the root showed the highest bond strength. Adhesive failures were the highest followed by mixed failures.

The effect of various surface treatments on the repair bond strength of denture bases produced by digital and conventional methods.

There is limited information on the repairability of prostheses produced with digital technology. This study aims to evaluate various surface treatments on flexural bond strength of repaired dentured base resins produced by digital and conventional methods. A total of 360 samples were prepared from one heat-polymerized, one CAD/CAM milled and one 3D printed denture base materials. All of the test samples were subjected to thermocycling (5-55°C, 5000 cycles) before and after repair with auto-polymerizing acrylic resin. The test samples were divided into five subgroups according to the surface treatment: grinding with silicon carbide (SC), sandblasting with Al2O3 (SB), Er:YAG laser (L), plasma (P) and negative control (NC) group (no treatment). In addition, the positive control (PC) group consisted of intact samples for the flexural strength test. Surface roughness measurements were performed with a profilometer. After repairing the test samples, a universal test device determined the flexural strength values. Both the surface topography and the fractured surfaces of samples were examined by SEM analysis. The elemental composition of the tested samples was analyzed by EDS. Kruskal-Wallis and Mann-Whitney U tests were performed for statistical analysis of data. SB and L surface treatments statistically significantly increased the surface roughness values of all three materials compared to NC subgroups (p < 0.001). The flexural strength values of the PC groups in all three test materials were significantly higher than those of the other groups (p < 0.001). The repair flexural strength values were statistically different between the SC-SB, L-SB, and NC-SB subgroups for the CAD/CAM groups, and the L-SC and L-NC subgroups for the 3D groups (p < 0.001). The surface treatments applied to the CAD/CAM and heat-polymerized groups did not result in a statistically significant difference in the repair flexural strength values compared to the NC groups (p > 0.05). Laser surface treatment has been the most powerful repair method for 3D printing technique. Surface treatments led to similar repair flexural strengths to untreated groups for CAD/CAM milled and heat-polymerized test samples.

Effect of Surface Treatment of Zirconia on the Shear Bond Strength of Resin Cement: A Systematic Review and Meta-Analysis.

This systematic review and meta-analysis aimed to evaluate the effect of different surface treatments on the shear bond strength (SBS) values between zirconia and resin cement compared to untreated specimens. The effects of various surface treatments on the bond strength between zirconia and resin cement were investigated by searching relevant articles on PubMed, ScienceDirect, and Google Scholar databases. A total of 13 studies that met the inclusion and exclusion criteria and addressed the research question were selected for statistical analysis. The studies were evaluated for heterogeneity, and a meta-analysis was performed. In total, 13 in vitro studies were included in accordance with the eligibility criteria. All 13 studies consistently demonstrated that silica coating yielded the highest SBS, followed by sandblasting and laser treatments. The meta-analysis using a random-effect model indicated a significant intergroup comparison, except for a few studies. Among the three treatments examined, the silica coating of zirconia was identified as the most effective in enhancing the bond strength between zirconia and resin cement. Further controlled laboratory and clinical studies are necessary to validate these findings and explore additional factors that may influence the effects of these surface treatments.

Effect of chemical or mechanical finishing/polishing and immersion in staining solutions on the roughness, microhardness, and color stability of CAD-CAM monolithic ceramics.

To evaluate the effects of various surface treatments and immersion in coloring substances on the roughness, microhardness, and color stability of CAD-CAM monolithic ceramics. The ceramics used were lithium disilicate reinforced with zirconium dioxide (Suprinity), lithium disilicate (E.max) or leucite (Empress). They were subjected to two surface treatments: glazing (group G) (n=20) or mechanical polishing (group P) (n=20). Then they were divided into two subgroups (n=10) to be treated with the staining substance (coffee or water). Roughness, microhardness and color were measured before and after treatment. Data were subjected to analysis of variance and multiple comparisons were performed with Tukey tests at 5% significance level. Roughness was lower in all tested ceramics after polishing than after glazing. Microhardness was the same for polished and glazed E.max, higher in glazed than polished Empress, and higher in polished than glazed Suprinity. Analysis of the effects of glazing and polishing on the individual ceramics showed that the ΔE2000 and ΔWID data of the E.max ceramic subjected to polishing showed greater change. Mechanical polishing is a good option for surface treatment of monolithic ceramics. Glazing was inferior and less satisfactory than polishing. Glazing generates changes that can lead to color instability.

Comparison of the Effect of Various Surface Treatments on the Microtensile Bond Strength of Lithium Disilicate Ceramic with Dentin- An In-vitro Study

AIM AND OBJECTIVE: The aim of this study was to evaluate and compare the effect of various surface treatments on the microtensile bond strength of Lithium disilicate ceramic with dentin.&#x0D; MATERIALS AND METHODS: A total of 45 human extracted premolars were obtained for the study. The samples were mounted in dental stone blocks having two “V” shaped notch on mesial and distal side of the mounted tooth. The samples were divided into three groups with 15 samples in each. The GROUP-A Control (without any surface treatment), GROUP-B (air abrasion with Al2O3 particles for 15 seconds) and GROUP-C (laser treatment for 5 seconds). Standardize tooth preparation was done on samples and lithium disilicate crowns were fabricated with a loop on occlusal surface. After surface treatment crowns were luted with self adhesive resin cement and pull out load test was performed in universal testing machine. The data was analysed using one way ANOVA TEST for multiple group comparison followed by Tusky HSD post hoc test. Level of significance was considered at 5% (p-value&lt;0.05).&#x0D; RESULTS: The surface treatment considerably increased the retention of lithium disilicate crowns. The air abrasion group showed the highest microtensile bond strength values. There was significant difference between air abrasion and laser treatment groups.&#x0D; CONCLUSION: It was evident that microtensile bond strength was adequately increased after both the surface treatments (air abrasion with Al2O3 particles and laser treatment) and there was significant increase in bond strength with air abrasion with Al2O3 particles group when compared to laser treatment group.

Effect of Different Surface Treatments and Application Times on Shear Bond Strength Between Polyetheretherketone and Composite Resin

Objective: To investigate the effect of various surface treatments and different application times on shear bond strength between polyetheretherketone and composite resin. Methods: A total of 110 disc-shaped polyetheretherketone specimens were randomly divided into 9 groups and 4 different surface treatments (control, sandblasting, tribochemical silica coating, sulfuric acid) were applied. The sandblasting, tribochemical silica coating, and sulfuric acid processes were performed 3 different times (10s, 15s, 20s). Then, the composite resins were applied to the treated surfaces of the polyetheretherketone specimens. The shear bond strength test and scanning electron microscopy analysis were performed. The data were statistically analyzed using analysis of variance and Duncan honest significant difference test. Results: One-way analysis of variance revealed differences in shear bond strength among the groups (p &lt;0.001). While the control group showed the lowest bond strength values (4.24 ± 1.53 MPa), 20 s of sulfuric acid process showed the highest bond strength values (27.91 ± 4.44 MPa). Conclusion: Depending on the application time to the material, additional surface treatments increase the polyetheretherketone composite bonding. Surface treatments with sulfuric acid applications provide higher surface bonding values than other treatments

Advances in Coating Adhesion Testing Using the Blister Test, Digital Image Correlation and Finite Element Methods

Adhesively bonded aluminum joints are widely used in multiple engineering sectors, especially the automotive industry. In long-term service, environmental conditions and stresses caused by factors such as internal deformation, residual stresses, or corrosion, cause adhesion strength degradation. Quantifying the adhesion strength is a complex task. While many different adhesion tests are available, the Blister Test (BT) is the only one that provides a measure of the normalized energy required to initiate and propagate a crack at the polymer/substrate interface.The adhesion strength of coatings on aluminum substrate for automotive applications was investigated using the Blister Test (BT) along with Digital Image Correlation (DIC), and Finite Element Methods (FEM). The BT was performed by pressurizing a fluid through a hole in the substrate, which causes blistering on the coating, ultimately leading to delamination. This test is performed after exposure of samples to an accelerated corrosion exposure. The DIC system obtains a full field displacement history of the de-adhesion mechanism using high speed cameras by tracking small subsets of the material in its field of view. This full field displacement history obtained from the BT is compared against theoretical displacements obtained through FEM and an inverse optimization algorithm, allowing the quantification of adhesion strength. Along with the BT, the effects of the surface treatments will be appraised through filiform corrosion (FC) testing.While there have been multiple investigations in the field of adhesion strength using the BT, the incorporation of a DIC system allows recording of the full field shape of blister evolution and debonding propagation. The use of FEM and inverse optimization algorithm to determine the adhesion strength allows for these calculations without making typical assumptions such as constant curvature and small deformations. The appraisal of FC which is prevenient in the automotive industry, along with the BT allows a better understanding of the effects of various surface treatments on adhesion strength and corrosion.

Effect of various surface treatments by the sol-gel method on the bond and flexural strengths of zirconia-porcelain

본 연구는 졸-겔법에 의한 실리카 코팅이 지르코니아와 포세린 간의 결합에 미치는 영향에 대해 조사하고자 하였다. 현재 상용화되어 있는 지르코니아(IPS, E-Max, ZirCAD)를 사용하여 국제 표준(ISO 9693:2019) 규격에 맞추어 정밀한 기계가공을 통하여 시편을 제작하였다. 시편은 미처리 그룹(대조군), 50 μm 샌드블라스터, 110 μm 샌드블라스터, 0.5 mol% 졸-겔, 및 0.25 mol% 졸-겔 처리한 그룹으로 분류하였다. 대조군은 연마 처리만 하였으며, 샌드블라스터 그룹은 산화 알류미늄을 사용하고, 졸-겔 그룹은 시험수용액에 함침과 건조과정 이 후 제조사의 지시대로 소결 과정을 거쳤다. 소결된 시편은 연마 과정을 거치고, 전용 몰드를 사용하여 지르코니아 시편 위에 축성 후 제조사의 지시대로 소성하였다. 본 연구에서는 만능시험기를 사용하여 시편 중앙 부위에서 파절이 일어날 때까지 하중을 가하여 강도를 측정하였다. 초기 지르코니아와 포세린과의 결합이 떨어지는 결과를 비교해보면, 0.5 mol% 졸-겔 그룹과 0.25 mol% 졸-겔 그룹은 다른 나머지 세 그룹에 비해 높은 결합강도 값을 나타냈으며, 특히 대조군 및 110 μm 샌드블라스터 그룹과 통계적 유의차를 보여주었다. 대조군 및 샌드블라스터 그룹들은 실리카를 처리하지 않아 상대적으로 낮은 결합강도 값을 보여주었지만, 이 중 50 μm 샌드블라스터 그룹은 거친 표면으로 인해 약간 높은 결과 값을 나타냈다. 이 후 꾸준히 하중을 가하여 최종적으로 지르코니아가 파괴되었을 때의 결과는 결합강도와는 다르게 실리카 침투로 인한 탄성계수의 변화로 인해 졸-겔 그룹들이 낮은 파절강도 값을 보여주었다. 이 또한 졸-겔 그룹들은 대조군 및 110 μm 샌드블라스터 그룹과 통계적 유의차를 보여주었다. 나머지 세 그룹들은 제조사에서 발표된 파절강도 값과 크게 상회하지 않은 값을 나타냈다. 이 결과로써 지르코니아와 포세린 결합시 졸-겔법에 의핸실리카 침투를 한 경우 결합강도 값은 높아지나 탄성계수 변화에 의해 지르코니아 최종 파절강도는 낮아지는 것으로 결론지었다.

Effect of Various Surface Treatments on Wettability and Morphological Properties of Titanium Oxide Thin Films.

The effect of three popular surface activation methods for a titanium oxide (titania) surface was thoroughly investigated to identify the most effective protocol for the enhancement of hydrophilicity. All the methods, namely H2O2 activation, UV irradiation and oxygen plasma treatment resulted in an enhanced hydrophilic titania surface, which was evidenced by the reduced contact angle values. To study in detail the chemical and morphological features responsible for the increased hydrophilicity, the treated surfaces were submitted to inspection with atomic force microscopy and X-ray photoelectron spectroscopy. The correlation between the treatment and titania surface hydroxylation as well as hydrophilic behavior have been discussed.

Nd:YVO4 laser groove treatment can improve the shear bond strength between dental PEEK and adhesive resin cement with an adhesive system.

The purpose of this study was to investigate the effect of various surface treatments on the shear bond strength between dental polyetheretherketone (PEEK) and adhesive resin cement. Two hundred and forty specimens were randomly classified into four groups: no treatment, sandblasted, sulfuric-acid-etched, and laser-grooved treatment. Each group was classified into two adhesive resin cement subgroups. Surface roughness, water contact angle, shear bond strength, and failure mode were measured; SEM and XPS results were obtained. The data were statistically analyzed using one-way or two-way analysis of variance and Tukey's honest significant difference test (α=0.05). Laser-grooved PEEK surface showed regular grooves and carbonization by thermal degradation; the surface roughness as well as water contact angle of were the highest in all groups. Shear bond strength values were significantly higher in the laser-groove-treated and sulfuric-acid-etched groups. Laser-groove-treated specimens showed cohesive failure. Laser-grooved treatment can improve shear bond strength between PEEK and adhesive resin cement.

Fatigue behavior and modeling of additively manufactured IN718: The effect of surface treatments and surface measurement techniques

• Effect of five surface treatments on surface topography of LB-PBF IN718 was studied. • Surface measurements using optical microscopy and X-ray CT (XCT) were compared. • Surface profiles were constructed from XCT images by curving-fitting edge detection. • The effect of surface roughness was more significant in high cycle fatigue regime. • A modified fatigue notch factor model correlated surface parameters with fatigue life. In this study, the effect of various surface treatments, including sand-blasting, drag-finishing, turning, grinding, and grinding + drag-finishing, on surface roughness and fatigue properties of laser beam powder bed fused Inconel 718 was examined. The surface roughness values obtained from two surface measurement techniques, i.e., optical microscopy and X-ray computed tomography, were compared. Both surface measurement techniques consistently indicated that all surface treatments led to improvements in surface roughness, although optical microscopy was influenced by surface glares and overestimated the surface roughness values of drag-finished specimens. Accordingly, all surface treatments also led to improvement in fatigue resistance with sand-blasting and drag-finishing yielding the least while grinding + drag-finishing causing the most. Notably, only the cracks of grinding + drag-finished specimens initiated from crystallographic facets while those in other conditions were surface initiated. Furthermore, by treating the surface valleys as micro notches, an effective fatigue notch factor model using a hybrid surface roughness metric that incorporates several standard surface roughness parameters was shown to correlate the fatigue lives of 94 % of specimens with various surface conditions within a scatter band of three.

Bond strength of self-adhesive resin cements to a high transparency zirconia crown and dentin

Background/purposeThe bond strength and durability of highly translucent zirconia ceramics to dentin is still unclear. The purpose of this study was to investigate the effect of various surface treatments on the bond strength of self-adhesive resin cements to high-translucent zirconia crowns and dentin. Materials and methodsA high-transparent zirconia and three self-adhesive resin cements (G-CEM LinkAce (GCL), RelyX U200 (RXU) and TotalCem (TTC)) were used. The zirconia surface was sandblasted with 50 μm alumina particles or coated with an SR Link primer, while a dentin primer (Tetric N-Bond Universal, TBU) was applied to the surface of the dentin. By using three self-adhesive resin cements, zirconia samples were bonded to the dentin surfaces of human teeth. The shear strength of the specimens was measured before and after 10,000-cycle thermocycling or 90-day aging. ResultsWhen using GCL to bond with the untreated dentin and various zirconia surfaces, the shear bond strength of the sandblasted (ZSB) and RS Link primer-coated (ZLK) groups was significantly higher than that of the untreated control group (Zc). However, in the case of TBU-treated dentin, the shear strength of the ZSB + LK + DTBU group was significantly higher than that of the other groups. After thermocycling and aging, the shear strength of the ZSB + LK + DTBU group using GCL and RXU cements decreased slightly, while the TTC showed no impact. ConclusionThe zirconia surface pretreated by sandblasting and bonding agent, which was sequentially bonded with a primer-treated dentin by using resin cements, can provide excellent shear bond strength and anti-aging performance.