Surface Treatment Protocols Research Articles

Shear Bond Strength of a Direct Resin Composite to CAD-CAM Composite Blocks: Relative Contribution of Micromechanical and Chemical Block Surface Treatment.

This study aims to compare the shear bond strength (SBS) of a direct resin composite to CAD-CAM resin composite blocks treated with different surface treatments: micromechanical, chemical or a combination of both. Eight CAD-CAM resin composite blocks, namely Brilliant Crios, Cerasmart 270, Vita Enamic, Grandio block, Katana Avencia, Lava Ultimate, Tetric CAD and Shofu Block HC were chosen. The micromechanical surface treatment protocols tested were hydrofluoric acid, polyacrylic acid or sandblasting, and the chemical one was a universal primer. These treated CAD-CAM blocks were tested to determine the SBS of a light-curing composite resin Z100 bonded to their surface. Two-way ANOVA followed by Tukey’s post hoc test was used to investigate the difference in SBS. Failures were analyzed by Fisher’s exact test. Bonding interfaces were examined by scanning electron microscopy. The micromechanical surface treatments give the highest SBS values: sandblasting appears to be the most efficient procedure for dispersed filler composite blocks, while hydrofluoric acid etching is preferable for polymer-infiltrated ceramic network (PICN) blocks. The use of universal primer does not improve SBS values on dispersed filler composite blocks. For PICN blocks, the use of universal primer significantly increases SBS values when combined with hydrofluoric acid etching.

Impact of fluoride-releasing orthodontic adhesives on the shear bond strength of orthodontic brackets to eroded enamel following different surface treatment protocols.

PURPOSE:To assess the impact of enamel surface treatment protocols and the types of adhesive materials on the shear bond strength (SBS) of brackets to eroded enamel substrate.MATERIALS AND METHODS:Eighty extracted premolars were randomly assigned to four main groups in which group C (no treatment) was the control group. The remaining groups were exposed to an erosion challenge through short-term acidic exposure to HCl solution (0.01 M, pH 2.3) for 30 s, with an agitation speed of 50 rpm at an environmental temperature of 25°C. The eroded enamel surface within each group was treated as follows: group N received no treatment; in group P, the eroded enamel was treated with 35% phosphoric acid (Ultradent Products, South Jordan, UT, USA) for 15 s, followed by a rinse for 10 s; and in group F, the eroded enamel was treated with fluoride gel (Bifluorid 12; Voco-GmbH, Cuxhaven, Germany) for 4 min. The brackets were bonded with either a resin composite adhesive (Transbond XT; light-cure adhesive, 3M Unitek, CA, USA) or resin-modified glass ionomer cement (Fuji Ortho LC-GC Corporation, Japan). The specimens were tested for SBS, and the bond failure was assessed according to the adhesive remnant index (ARI). Analysis of variance (ANOVA) and Tukey's post-hoc tests (P < 0.05) were used to compare the SBS of the groups. The ARI values between the groups were recorded.RESULTS:Statistically significant differences were found among the tested variables (P < 0.05). Group P showed the highest mean SBS values regardless of the type of adhesive used, and the difference was statistically significant (P < 0.05). The application of the fluoride gel showed no statistically significant improvement in SBS values. The failure mode distribution among the test groups indicated that failures at the adhesive–bracket interface were predominant in group C compared with the other study groups.CONCLUSIONS:Fluoride pretreatment, which was used to remineralize the eroded enamel surfaces before bonding, resulted in a decrease in the SBS of the orthodontic brackets in vitro compared with the other treated groups. The use of fluoride-releasing adhesive also enhances bonding to the eroded enamel surfaces.

Surface Characterisation of Dental Resin Composites Related to Conditioning and Finishing.

Due to the little information related to surface processing and conditioning of resin matrix ceramic materials previous glazing, the main purpose of this in vitro study was to investigate the effect of different surface treatments on the surface morphology of different resin composite materials. Five types of resin composite CAD-CAM materials: a resin composite ceramic Vita Enamic (E) and four types of nanoparticle-filled resins, like Lava Ultimate (L), Cerasmart (C), Shofu HC (S), Hyramic (H) were taken into consideration. Specimens received the following surface treatment protocols: conventional polishing [p], polishing and glazing [pg], conditioning with CoJet [c], conditioning with CoJet and glazing [cg], sandblasting [s], sandblasting and glazing [sg], etching [e], etching and glazing [eg]. Surface roughness was analyzed for all samples and nanosurface topographic characterization was made by Atomic Force Microscopy. The highest roughness was registered for sandblasted surfaces [s], followed by tribochemical silica airborne particle abrasion [c], and etching [e]. A very strong correlated conditioning behavior of resin nanoceramic materials, like L, C and S samples was found. The microroughness decreased thus [s] > [c] > [e]. These are moderate correlated with H, and are moderate negative correlated to E, where e is more efficient. Three-dimensional images indicated visible grain boundaries after conditioning, for all materials. After polishing and glazing, surfaces became smoother. For all tested conditioning and finishing methods, surface roughness values were within clinically acceptable limits. Finishing by polishing was proved to be a good choice for all materials taken into consideration, polishing and glazing likewise, excepting Hyramic. For Enamic and Shofu HC sandblasting or tribochemical conditioning and glazing and for Hyramic polishing and glazing are not the best options, related to nanoroughness values. Referring to the nanosurface topography, for Enamic, Cerasmart and Hyramic, glazing would be the method of choice, associated with the adequate conditioning method for each material.

Repair potential of a bulk-fill resin composite: Effect of different surface-treatment protocols.

This study evaluated the effect of different surface-treatment protocols on the repair bond strength of a bulk-fill resin composite. One-hundred and forty specimens (Filtek Bulk-fill) were created (5mm diameter, 4mm depth) and allocated to one of 14 groups according to surface treatment (no treatment, tribochemical silica coating, sandblasting with aluminum oxide), adhesive application (no adhesive, total-etch, self-etch), and type of repair resin (bulk-fill, universal resin) (n=10 per group). Twenty specimens were selected for measuring the cohesive strengths of non-aged resin composites and used as reference. Other specimens were thermocycled. Shear bond-strength testing was performed. Data were analyzed using linear regression of bond strength as a function of the surface treatment, type of adhesive and whether or not adhesive was applied, and type of repair resin. The failure modes were analyzed using logistic regression of failure mode (cohesive failure vs. other types, or adhesive failure vs. other types) on the type of surface treatment, adhesive application, and repair resin used. Surface treatment, regardless of whether this was tribochemical silica coating (mean difference=5.44MPa; 95% CI=4.77-6.11) or sandblasting with aluminum oxide (mean difference=4.22MPa; 95% CI=3.55-4.88), resulted in higher shear bond strength than no treatment. Application of adhesive resulted in a substantial and statistically significant decrease of shear bond strength (by 8.77MPa, for self-etch and by 7.26MPa for total-etch) relative to no adhesive. Conversely, the type of repair resin did not influence the shear bond strength to any appreciable extent.

The Effect of Different Surface Treatment Protocols on the Shear Bond Strength to Repressed Lithium Disilicate Glass Ceramics

Objective: The present study aimed to evaluate the effect of repressing and different surface treatment protocols on the shear bond strength of lithium disilicate glass-ceramics. Material and Methods: A total of 52 lithium disilicate glass-ceramic discs (IPS emax Press, Ivoclar Vivadent) were fabricated using the heat-press technique. The discs were divided into two groups; group (P): discs fabricated from new e.max ingots (n=26), group (R): discs fabricated from reused e.max buttons (n=26). Each group was subdivided into subgroup (E): discs were etched with hydrofluoric acid (9.5%) (n=13), subgroup (S): discs were air-abraded with 110 µm alumina particles. All specimens were subjected to X-ray Diffraction analysis, Scanning Electron Microscope, Energy Dispersive X-Ray, Thermo-Cycling, and Shear Bond Strength Testing. Results: Repressed Etched subgroup (RE) recorded the statistically highest shear bond strength value, followed by the Pressed Etched subgroup (PE), while the statistically lowest shear bond strength value was recorded for the Pressed Air-Abraded subgroup (PS) and Repressed Air-Abraded subgroup (RS). Conclusion: Repressing the leftover buttons for the construction of new lithium disilicate glass-ceramic restorations has no adverse effect on the bond strength of the resin cement to the ceramic. Hydrofluoric acid surface treatment improves the shear bond strength and durability of resin cement bond to both pressed and repressed lithium disilicate glass-ceramic. Air-abrasion cannot be considered as a reliable surface treatment when bonding to lithium disilicate glass-ceramics. Keywords Heat pressed; Lithium disilicate glass-ceramics; Repressing; Shear bond strength; Surface treatment.

Effect of Er,Cr:YSGG Laser Versus Acid Etching Surface Treatment on the Surface Roughness and Topography of Two Pressable Lithium Disilicate Ceramics. “In-Vitro Study”.

Objective: To assess the effect of two surface treatment protocols of two pressable lithium disilicate ceramics with different thicknesses on the surface roughness and topography. Material and methods: Sixty four lithium disilicate ceramic discs were divided into two groups (n=32); IPS e.max Press and InitialTM LiSi Press. Each group was subdivided into two subgroups (n=16) according to thicknesses (0.5mm and 1mm). Each subgroup was divided into two subdivisions (n=8) according to the surface treatment; Er:Cr:YSGG Laser and hydrofluoric acid etching. Artificial aging was performed for all the specimens. Surface roughness (Ra) before and after surface treatment protocol was measured using contact stylus profilometer and their topographical changes were identified using scanning electron microscope. Results: there was no significant difference in Ra values between the two ceramic types before and after surface treatment. There was no significant difference in Ra values between the two surface treatments on both ceramics. There was a difference in the effect of the surface treatments on the topography of the ceramics Conclusion: Both surface treatments have comparable effect on the surface roughness of lithium disilicate ceramic but have different effect on the ceramic’s topography.

Effect of Surface Treatments on the Flexural Strength of HeatPressed Zirconia Reinforced Lithium Silicate Ceramic and HeatPressed Lithium Disilicate Ceramic

Objective: To compare the flexural strength of heat-pressed zirconia-reinforced lithium silicate (Celta Press) with that of heatpressed lithium disilicate (IPS e.max Press) and to evaluate the effect of surface treatments. Materials and Methods: Sixty-four specimens, with dimensions of 14.5 x 12.5 mm and 1.5 mm thickness, were fabricated using the lost-wax heat press technique and were divided into two groups: Group 1, Celta Press and Group 2, IPS e.max Press. Each group had four subgroups according to the surface treatment protocols: No treatment (A); Polished (B); Glazed (C), and Polished and Glazed (D). The specimens’ flexural strength was calculated by a universal testing machine in MPa. Results: IPS e.max Group D, showed the greatest flexural strength (374.22 ± 87.35MPa), while Celtra Press Group C, had the lowest flexural value (164.10 ± 51.97MPa). A two-way ANOVA indicated that IPS e.max exhibited statistically significantly greater flexural strength than Celtra Press. Tukey’s HSD test revealed that the polished and glazed group displayed greater flexural strength than the untreated group. Conclusion: IPS e.max Press showed greater flexural strength than Celtra Press among all groups. The combination of a polished and glazed surface produced greater flexural strength than the untreated group. Clinical Significance: With newer dental ceramic materials constantly emerging, there is a need to evaluate their mechanical properties and provide clinical recommendations. The aim of this in vitro study is to compare the flexural strength of two highly esthetic ceramic materials, Celtra Press and IPS e.max Press, and to offer some guidelines regarding their surface treatment protocol.

Cleaning and Surface Treatment Protocols for Repair of Aged Y-TZP with Composite Resin.

The purpose of this study was to evaluate the cleaning and surface treatment techniques in the repair of aged and contaminated yttrium oxide-stabilized tetragonal polycrystalline zirconia (Y-TZP). From a total of 80 specimens of Y-TZP, 60 were subjected to aging simulation in a buccal environment with degradation in an autoclave for 24 hours (127°C/1.5 bar) and contaminated with Streptococcus mutans. The surfaces were cleaned with a triple syringe (air/water jet; n = 20) or isopropyl alcohol (n = 20), or by prophylaxis (n = 20) with pumice and water. The remaining 20 specimens comprised the control group. All specimens were then treated with silicatization (n = 10 per group) or adhesive (n = 10 per group) and repaired with composite resin. Analyses of shear strength, failure mode, and roughness were performed by electron microscopy. Data were analyzed by two-way analysis of variance (ANOVA) and t test (α = .05). Statistical significance was set at P < .05. Two-way ANOVA was significant for aging and surface treatments (P = .049), but was not significant for surface cleaning (P = .05). ANOVA results were statistically significant for surface treatments (P < .0001), with higher resistance for the silicatization groups. The failure mode was mostly adhesive for all specimens. The roughness was not significant for aging and control groups (P > .05). Triple-syringe and prophylaxis cleansing followed by silicatization was the most efficient treatment for the repair of aged and contaminated Y-TZP. There is reduced repair efficiency with the aging of Y-TZP.

Bonding performance of dispersed filler resin composite CAD/CAM blocks with different surface treatment protocols.

The effect of various pretreatments on the bonding of a resin cement to resin-composite CAD/CAM blocks (RCBs) was examined. The surface of dispersed-filler RCBs (DF-RCBs) and a polymer infiltrated ceramic network RCB (PICN-RCB) was roughened using hydrofluoric acid etching (HF) or sandblasting, and followed by silanization and/or universal adhesive (UA) application. Microtensile bond strength (µTBS), surface roughness parameters (arithmetical mean height (Sa); developed interfacial area ratio (Sdr)), and critical surface energy (γc) were determined. For most DF-RCBs, the highest µTBS was obtained using HF+UA. UA application to DF-RCBs resulted in similar or higher µTBS compared to silanization, which indicates that silane treatment is not crucial for DF-RCBs, especially after HF. In contrast, the highest µTBS to PICN-RCB was obtained with silanization. Both roughening pretreatments significantly increased the surface roughness parameters and the γc of all RCBs. The γc was positively correlated with Sa (r=0.756, p<0.001) and Sdr (r=0.837, p<0.001).

Combined application of femtosecond laser and air-abrasion protocols to monolithic zirconia at different sintering stages: Effects on surface roughness and resin bond strength.

This study aimed to investigate the effects of femtosecond laser (Fs) and/or air-abrasion protocols on surface roughness (Ra) of zirconia and resin bond strength. Eighty zirconia samples were randomly divided into eight subgroups according to surface treatment protocols: Control (C), Air-abrasion before sintering (ABS), Air-abrasion after sintering (AAS), Air-abrasion before and after sintering (ABS + AAS), Fs laser before sintering (FBS), Fs laser before sintering + air-abrasion after sintering (FBS + AAS), Fs laser after sintering (FAS), and Fs laser after sintering + air-abrasion after sintering (FAS + AAS). Measurements of Ra values were obtained using a surface profilometer. Surface morphological properties were evaluated with scanning electron microscopy (SEM), and crystallographic changes were examined by X-Ray diffractometry (XRD). Self-adhesive resin cement was bonded to zirconia samples, and shear bond strength (SBS) tests were performed. The data were statistically analyzed by one-way ANOVA, followed by Tamhane tests. The control group displayed the lowest Ra and SBS values among all groups. The highest Ra and SBS values were found in the FBS and FBS + AAS groups. Air-abrasion applied before sintering significantly increased the Ra of specimens. FAS, FAS + AAS, and ABS + AAS groups exhibited higher SBS values than AAS and ABS (p < .05). Air-abrasion applied after Fs laser did not produce any significant change in the Ra and SBS compared to Fs laser alone (p > .05). Femtosecond laser application may be a promising method to enhance the surface roughness of zirconia and improve resin bond strength. Air-abrasion at pre- and post-sintered stages may also be a viable surface treatment option.

The Influence of Surface Roughening and Polishing on Microbial Biofilm Development on Different Ceramic Materials.

To test the hypothesis that surface roughening and polishing of ceramics have no effect on their surface roughness and biofilm adhesion. Feldspathic ceramic Vitablocks™ TriLuxe forte (VTF), lithium disilicate glass IPS e.max Press™ (IPS) and zirconia reinforced lithium silicate Vita Suprinity™ (VS) ceramic blocks (n = 27 per group) were prepared from sintered CAD blocks using a water-cooled saw. They were further subdivided into 3 subgroups according to the surface treatment protocols (n = 9): as prepared, roughened and polished. The surface roughness of the ceramic blocks was measured using an electro-mechanical profilometer. The ceramic sections were inoculated with Streptococcus mutans and incubated for 48 hours to form a biofilm. The ceramic surfaces with the biofilms were analyzed using Confocal Laser Scanning Microscopy to calculate the percentage of live bacteria and substratum coverage by the biofilm, and further visualized using scanning electron microscopy. Statistical analysis was done with SPSS software using two-way ANOVA, followed by post hoc Bonferroni test to identify significant differences between the groups. The level of significance was set at p = 0.05. As prepared VTF showed significantly higher mean surface roughness values than as prepared IPS and VS. The mean percentage of live bacteria and biofilm coverage of the substrate were significantly higher in the roughened ceramic blocks than the as prepared and polished blocks for all three ceramic types (p < 0.05). Polished specimens of VS significantly lower percentage of biofilm coverage than the other groups (p < 0.05). This study sheds new light that adjustments of ceramic restorations prior to cementation increases the likelihood for formation and adhesion of microbial biofilms on the surface. Polished zirconia reinforced lithium disilicate ceramics demonstrated the lowest bacterial adhesion among the evaluated ceramics.

The influence of different surface treatment protocols and bonding agents on the repair microtensile bond strength of six-month’ aged composite: An in vitro study

Objective: to compare the effect of three surface treatment protocols and two intermediate agents on repairing aged composite, regarding microtensile bond strength (µTBS) and mode of fracture, at two time intervals. Material and methods: Six-month aged microhybrid composite blocks, were randomly distributed into three groups, subjected to; Fine, Super Fine grit diamond burs or Erbium- Yag Laser surface treatment. Each block had both One Coat bond SL (Bond) and Brilliant Flow flowable composite (Flow) intermediate agents, alongside. Blocks were incrementally repaired using nanohybrid composite, cut into beams, then randomly subjected either immediately (IM) to µTBS test or after thermocycling (TC) for 5000 cycle. Mode of failure was determined using stereomicroscope. Data were analyzed through three-way ANOVA followed by pairwise comparison with Bonferroni correction. Kruskal Wallis test compared groups for failure mode analysis (?=0.05)Results: Super Fine grit showed the highest mean µTBS compared to control for both intermediate agents, IM and after TC at P&lt;0.05. No difference between Fine grit and Laser application for all groups (P&gt;0.05). IM, Bond showed the highest µTBS compared to TC, Flow for all tested groups. Beams roughened with Fine and Super Fine burs showed significantly lower adhesive failures than those roughened with Laser. Flow suffers significantly higher adhesive failure than those with Bond. For TC tested groups; beams with Super Fine bur and Bond showed significantly lower adhesive failure at P=0.029.Conclusions: Super Fine grit and Bond provide the highest µTBS and the least adhesive failure; moreover TC resulted in significant decrease in µTBS.

Clinical evaluation of a universal adhesive in non-carious cervical lesions.

To compare the clinical performance of a universal adhesive in class V non-carious cervical lesions (NCCLs) using two surface treatment protocols (self-etch [SfE] vs selective-enamel-etch [SelE]). Thirty-three adults, each with ≥2 NCCLs, received one resin composite restoration utilizing a SfE universal adhesive and another utilizing the adhesive and SelE with 37% phosphoric acid. Restorations were evaluated for sensitivity, retention, marginal discoloration, marginal adaptation, and clinical acceptability through 24 months using Cochran-Mantel-Haenszel tests for stratified, ordered categorical outcomes. Sixty-six restorations (35 SfE, 31 SelE; 27 volunteers) were evaluated at 24 months. There were no significant differences between SfE and SelE for sensitivity, retention, marginal adaptation, or clinical acceptability. One SfE restoration was lost. Marginal adaptation was significantly worse at 24 months than baseline for SelE (P = 0.01), but not for SfE. Marginal discoloration was significantly worse for SfE (P = 0.02), but not for SelE. Sensitivity improved from baseline to 24 months for both groups (SelE P = 0.004, SfE P = 0.002). Twenty-four-month data indicated significantly reduced sensitivity for both groups, worse marginal discoloration for SfE, and worse marginal adaptation for SelE. No changes in retention or clinical acceptability were observed in either group. All retained restorations were clinically acceptable at 24 months. Both self-etch and selective enamel etch techniques with a universal adhesive produced clinically acceptable results in resin composite restorations for NCCLs over 2 years.

Influence of different ceramic materials and surface treatments on the adhesion of Prevotella intermedia

Ceramics are used in oral rehabilitation; however, these materials are prone to formation of biofilms that may cause periodontal diseases. This study aimed to evaluate the influence of distinct surface treatments on ceramic surface roughness and biofilm formation of oral bacteria (Prevotella intermedia). Eighty-four specimens of the following four ceramic systems were produced: LC - leucite-based glass ceramic, LD - lithium disilicate-based glass ceramic, LSZ - glass ceramic based on zirconia-reinforced lithium silicate, and ZR - monolithic zirconia. These were submitted to three different surface treatment protocols: C - control, G - glazing, and GDB - grinding with diamond bur (n = 7). The surface characteristics were assessed using a confocal laser microscope (Ra) and a scanning electron microscope (SEM). Thereafter, the groups were contaminated with a bacterial strain of P. intermedia ATCC 25611. The biofilms formed were quantified by counting the colony forming units (CFUs) and analyzed with scanning electron microscope (SEM) and confocal laser scanning microscope (CLSM). Data were analyzed by using a 2-way ANOVA and the Tukey test (ɑ = 0.05). Results showed that greater roughness was associated with GDB (p < 0.05). The same was also true for the ceramic material ZR (p < 0.05). There was a statistical significant difference in the CFU counts between the materials (p < 0.05) that revealed a greater amount of bacterial adhesion in the LC and ZR groups (p > 0.05). Thus, it was suggested that the surface roughness of the ceramic materials favored bacterial adhesion; and thus, finishing of ceramic surfaces with GDB should be avoided.

Effect of different surface treatment protocols on bond strength to root dentin using bulk fill restorative material

Evaluate the influence of different surface treatment protocols on the bond strength of bulk fill restorative material to root dentin using the push-out test after cyclic loading. Forty intact human premolars, freshly extracted for orthodontic purpose with straight canals and fully developed apices, were selected for this study. The coronal portion of the teeth were cut perpendicular to the long axis of the teeth at the cement-enamel junction. All root canals were instrumented, cleaned, and obturated; then, a space of 3 mm in depth was prepared below the orifice level in both canals in each tooth to receive direct core bulk fill material; the specimens were classified according to the surface treatment protocol into four groups (n = 30). Group 1: no surface treatment (control group); group 2: surface treatment using Er,Cr:YSGG laser; group 3: surface treatment using chlorhexidine; and group 4: surface treatment using 17% EDTA solution. Restorations were bonded using universal adhesive following the same protocol. The roots were sectioned and three 1-mm-thick slices were obtained representing the length of the restorations inside the canals. The specimens were thermocycled, then subjected to push-out testing. A specimen from each group was examined using scanning electron microscope. Data was analyzed statistically using Kruskal-Wallis test and pairwise comparisons were carried out. The results showed that laser group was significantly higher than EDTA and chlorhexidine groups, and also higher than the control group with no significant difference. Also, the control group was significantly higher than EDTA and chlorhexidine group. However, chlorhexidine group was higher than EDTA group with no significant difference recorded (p < 0.05). Er,Cr:YSGG laser showed promising results in terms of bond strength to radicular dentin. But still the control group using universal adhesive can provide comparable and satisfactory results.

Current Considerations for Dental Ceramics and Their Respective Union Systems

Objetivo: avaliar as principais caracteristicas das cerâmicas odontológicas, cimentos resinosos, tratamentos de superfície e verificação dos seus devidos modos de falha, frente à literatura e suas respectivas utilizações clínicas. Material e Métodos: foi realizada uma busca bibliográfica nos principais bancos de dados de saúde PUBMED (www.pubmed.gov) e Scholar Google (www.scholar.google.com.br), no qual coletou-se trabalhos que foram publicados de 2002 a 2020. Foram inclusos estudos laboratoriais, relatos de casos, revisões sistemáticas e revisões de literatura, que fossem desenvolvidos em indivíduos vivos. Logo, foram excluídos artigos que não tratavam a respeito das caracteristicas das cerâmicas odontológicas, cimentos resinosos, tratamentos de superfície e verificação dos seus devidos modos de falha, frente à literatura e suas respectivas utilizações clínicas. Resultados: as cerâmicas podem ser classificadas em cerâmicas vítreas, cerâmicas policristalinas e as cerâmicas híbridas. Do mesmo modo que existem diferentes composições das cerâmicas e agentes de união, há também alguns protocolos de tratamento de superfície que se diferem de acordo com a escolha desses materiais. Conclusão: diversos sistemas cerâmicos estão disponíveis no mercado, fazendo com que os profissionais da área protética necessitem de uma constante reciclagem acerca das suas propriedades e indicações, visto que bons resultados não são devidos exclusivamente ao tipo de material utilizado, mas sim, à seleção do melhor material, tipo de preparo em conjunto à habilidade do profissional, cimentos resinosos, tratamentos de superfície e verificação dos seus devidos modos de falha. Nesse contexto, fazem-se necessários maiores estudos com relação às cerâmicas odontológicas e seu devido uso em um cenário clínico

Effect of Different Surface Treatments on the Repair of Aged Bulk-Fill Composites: An In Vitro Study

Objectives: The aim of this in vitro study was to evaluate the efficiency of different surface treatments on the microtensile bond strength (µTBS) of aged bulk-fill composite.Materials and Methods: Sixty bulk-fill resin-based composite (RBC) specimens in 5 x 5 x 5 dimensions were prepared. After the aging by thermal cycling for 5000 times between 5 and 55°C, substrate surfaces were abraded with SiC abrasive papers. Specimens were divided into 6 groups according to the surface treatment protocol: no surface treatment (control), control + Single Bond Universal (SBU; 3M ESPE) application, phosphoric acid etching (PA) + SBU, hydrofluoric acid etching (HF) + SBU, aluminum oxide air abrasion (AlO) + SBU, and tribochemical silica coating (TSC) + SBU. Surface roughness values were measured in five different directions using a contact profilometer (n=10). Then, specimens were repaired with a conventional RBC. After the repair, bonded specimens were cut into 1 mm2 beams and µTBS values were determined until failure at a crosshead speed of 0.5 mm/min. Specimen surfaces after surface treatments were observed by SEM. Data were analyzed using ANOVA and Tukey tests (p&amp;lt;0.05). Results: One-way ANOVA revealed significant difference (p&amp;lt;0.001) among the surface treatments. The lowest repair µTBS values were observed for the control group. SBU application alone significantly improved repair µTBS values (p&amp;lt;0.001). The highest µTBS values were obtained for the AlOand TSC, and HF followed. The surface roughness ranking for the five surface treatment protocols was as follows: TSC &amp;gt; AlO &amp;gt; HF &amp;gt; PA = Control. Conclusions: Aged bulk-fill RBCs can be successfully repaired if effective and safe repair protocol is chosen. The highest µTBS values were obtained for the AlO and TSC. The use of universal adhesive alone is promising to facilitate the repair of bulk-fill RBCs.

Effect of different surface treatment protocols on the shear bond strength of perforation repair materials to resin composite

The adhesion between the resin composite and perforation repair materials critically influences the treatment outcomes. This study aimed to investigate the effect of different surface treatment on the bond strength between the perforation repair materials and resin composite. Ninety blocks were prepared from Mineral trioxide aggregate (MTA) Angelus, EndoSequence (ERRM) and one experimental Nano-MTA (n = 30 each). Then, they were divided into two subgroups according to the surface treatment performed, which was either etching with phosphoric acid gel or air abrasion with Al2O3 particles. Adhesive system and resin composite were applied according to the manufacturers’ instructions. Specimens were tested for shear bond strength (SBS) tests using a universal testing machine. Failure modes were evaluated under a stereomicroscope. Data were analyzed using two-way ANOVA and Tukey’s test. Perforation repair materials had a significant effect on SBS at p = 0.0008, while the surface treatment showed an insignificant effect on the SBS at p = 0.0612. After both surface treatment techniques; ERRM revealed the highest SBS mean values followed by MTA Angelus then Nano-MTA. There was no statistically significant difference between each of ERRM and MTA Angelus, and between MTA Angelus and Nano-MTA. Cohesive and mixed modes of failures were the most predominant failure modes in all groups. ERRM had the best bonding to resin composite. Both tested surface treatments performed similarly with ERRM and the experimental Nano-MTA regarding SBS to resin composite. Air abrasion surface treatment was considered more successful with MTA Angelus compared to phosphoric acid regarding SBS to resin composite. Abbreviation: MTA: Mineral trioxide aggregate; ERRM: EndoSequenceBC RRM-Fast Set Putty; SBS: shear bond strength; Nano-WMTA: Nano-white mineral trioxide aggregate; TEM: Transmission electron microscope

Different surface treatment protocols of a Y-TZP ceramic with a superficial glaze layer

Aim: evaluate the influence of etching time with hydrofluoric acid on the bond strength of a Yttrium-stabilized polycrystalline tetragonal zirconia (Y-TZP) ceramic with a superficial glaze layer and a resin cement. Methods: Y-TZP blocks were cut to obtain 40 samples. They were distributed into four groups (n = 10): control treated by sandblasting with silica-coated alumina (RS) and three glazed experimental groups with different etching times: GS20s, GS60s and GS100s. Cementation was done with a universal adhesive and a resin cement. Two cement cylinders were made in each block. After thermocycling, the shear bond test was performed. Two extra samples of each group were made to obtain profilometry, scanning electron microscopy, mapping and backscattered electron detector images. Energy dispersive spectrometry and goniometry were also performed. Results: Kruskal-Wallis and Dunn tests demonstrated bond strength differences only between the RS (22.10MPa) and the GS groups (GS20s: 8,10Mpa; GS60s: 10.49MPa; GS100s: 7.53MPa) (p = 0.001), but there was no difference among the experimental groups (p &gt; 0.05). The contact angles were 55.33º (RS); 70.78° (GS100s); 48.20º (GS60s) and 28.73º (GS20s). ANOVA and Tukey test demonstrated similar wettability of RS to GS60s and GS100s (p &gt; 0.05), but all the experimental groups were statistically different between them (p &lt; 0.001). Qualitative image analysis revealed an irregular glaze distribution after etching. The thickness of the remaining glaze layer measured by profilometry was 5±1μm (GS20S), 4±1μm (GS60S) and 3±1μm (GS100s). Conclusion: The etching time of glazed zirconia did not influence the adhesive strength of the ceramic to the resin cement.

An in vitro evaluation of the effect of polishing on the stainability of different CAD/CAM ceramic materials

PurposeTo determine the effect of coffee on the stainability of CAD/CAM ceramics after different surface treatment protocols. MethodsNinety specimens (2 mm × 10 mm) of CAD/CAM ceramic materials (Vitablocs Mark II, VITA Enamic, and VITA Suprinity) were prepared. The specimens were subdivided (n = 10) into three groups: G1: Glazed (control group), G2: Subjected to finishing and polishing, and G3: Re-glazed after finishing and polishing. The surface treatment was performed using a diamond polishing system for porcelain (Diapol) followed by applying a diamond polishing paste (Diapolisher). The specimens were immersed in distilled water for 24 h, and the baseline color measurement after finishing and polishing was recorded. Each group was then immersed in a staining solution (coffee) for one week, and the second color measurement was recorded. ResultsThe color of the CAD/CAM ceramic materials in the finishing and polishing groups changed significantly after staining (P < 0.05). Statistically significant differences were noticed after staining in the polished groups of Vita Enamic and Vita Suprinity compared with the glazed group (control). However, the color change between the re-glazed and control groups was insignificant for all the materials (P > 0.05). Although the color change values of the three CAD/CAM materials increased, these changes were within the clinically acceptable value (ΔE < 3.3). ConclusionStaining of the tested CAD/CAM ceramic materials increased the color change values within the clinically acceptable range in all the groups, with the highest values found after finishing and polishing. Re-glazing is recommended after surface adjustment for all the tested materials to increase their resistance to staining.