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Images of the heating treatment methodology. A: Dispensing one drop of the HF (not previously heated) to the EMX surface. B: One drop of the HF was poured into a 1 mL eppendorf vial. C: With the lid closed, the eppendorf vial was positioned inside a device calibrated at 70 °C and remained for 1 min. D: The heated HF solution was placed on the EMX surface. E: application of a perpendicular air-heated stream to the EMX surface for 1 min before etching.
Source publication
The aim of this study was to evaluate the effects of hydrofluoric acid (HF) concentration and previous heat treatment (PHT) on the surface morphology and micro-shear bond strength (μSBS) of a lithium disilicate glass ceramic (EMX) to resin cement. One hundred four EMX specimens were randomly assigned to two groups (n=52) according to the HF concent...
Contexts in source publication
Context 1
... EMX specimens were randomly assigned into two groups (n=52) according to the hydrofluoric acid concentrations: 5% and 10% (Fórmula & Ação, São Paulo, SP, Brazil). Then, a new random distribution was made according to the previous heating treatments (PHT) (n=13): no PHT (control group); PHT of the hydrofluoric acid; PHT of the ceramic surface, and a combination of PHT hydrofluoric acid + PHT EMX surface. These procedures are detailed below. Control group: the EMX surface was etched with hydrofluoric acid at room temperature (25 °C ± 1) for 20 s and rinsed with an air-water spray for 30 s (Fig. ...
Context 2
... heat treatment: prior to etching, one drop of HF acid was heated to 70 °C in a pre-calibrated device (Figs. 1B and 1C). Then, the heated HF was dropped onto the ceramic surface (Fig. 1D), allowed to react for 20 s and rinsed with an air-water spray for 30 ...
Context 3
... heat treatment: prior to etching, one drop of HF acid was heated to 70 °C in a pre-calibrated device (Figs. 1B and 1C). Then, the heated HF was dropped onto the ceramic surface (Fig. 1D), allowed to react for 20 s and rinsed with an air-water spray for 30 ...
Context 4
... surface heat treatment: a hot-air stream was perpendicularly applied to the ceramic surface for 1 min before etching (Fig. 1E). The EMX surface temperature was measured with a digital infrared thermometer (model HT-450, Hikari, Shanghai, China), with a mean temperature of 85±1 °C recorded. Then, one drop of HF was poured onto the ceramic surface and maintained for 20 s (Fig. 1A). The surface was rinsed with an air-water spray for 30 ...
Context 5
... surface heat treatment: a hot-air stream was perpendicularly applied to the ceramic surface for 1 min before etching (Fig. 1E). The EMX surface temperature was measured with a digital infrared thermometer (model HT-450, Hikari, Shanghai, China), with a mean temperature of 85±1 °C recorded. Then, one drop of HF was poured onto the ceramic surface and maintained for 20 s (Fig. 1A). The surface was rinsed with an air-water spray for 30 ...
Similar publications
To investigate how the hydrofluoric acid (HF) concentrations applied to a lithium disilicate glass-ceramic (EMX) affects the surface morphology and microtensile bond strength (μTBS) of ceramics to dentin, using light-cured resin cements with or without UDMA. Sixty-three EMX square ceramic blocks were etched for 20 seconds using different HF concent...
The aim of this study was to evaluate the influence of different concentrations of hydrofluoric acid (HF) associated with varied etching times on the microshear bond strength (μSBS) of a resin cement to a lithium disilicate glass ceramic. Two hundred seventy-five ceramic blocks (IPS e.max Press [EMX], Ivoclar Vivadent), measuring 8 mm × 3 mm thickn...
Citations
... The differences between etching patterns are caused by lithium disilicate greater resistance to HF dissolution compared with that of SiO2 as twice the HF tration is needed to dissolve a single lithium disilicate molecule. [98,[117][118][119][120][121][122][123][124][125][126]. In etching LSCs had a negative impact on their flexural strength [98,119,120,127]. ...
... In etching LSCs had a negative impact on their flexural strength [98,119,120,127]. M etching with pre-heated HF (50-70 °C) yielded higher bond strengths compared w ing with room-temperature HF [124][125][126]. ...
... Acid etching with HF substitutes: Owing to the toxic and corrosive potenti as a result of its low dissociation constant, it can easily penetrate dermal, ep The differences between etching patterns are caused by lithium disilicate crystals' greater resistance to HF dissolution compared with that of SiO 2 as twice the HF concentration is needed to dissolve a single lithium disilicate molecule. [98,[117][118][119][120][121][122][123][124][125][126]. In general, etching LSCs had a negative impact on their flexural strength [98,119,120,127]. ...
Considering the rapid evolution of lithium silicate-based glass ceramics (LSCs) in dentistry , this review paper aims to present an updated overview of the recently introduced commercial novel LSCs. The clinical and in vitro English-language literature relating to the microstructure, manufacturing, strengthening, properties, surface treatments and clinical performance of LSC materials was obtained through an electronic search. Findings from relevant articles were extracted and summarised for this manuscript. There is considerable evidence supporting the mechanical and aesthetic competency of LSC variants, namely zirconia-reinforced lithium silicates and lithium-aluminium disilicates. Nonetheless, the literature assessing the biocompatibility and cytotoxicity of novel LSCs is scarce. An exploration of the chemical, mechanical and chemo-mechanical intaglio surface treatments-alternative to hydrofluoric acid etching-revealed promising adhesion performance for acid neutralisation and plasma treatment. The subtractive manufacturing methods of partially crystallised and fully crystallised LSC blocks and the additive manufacturing modalities pertaining to the fabrication of LSC dental restorations are addressed, wherein that challenges that could be encountered upon implementing novel additive manufacturing approaches using LSC print materials are highlighted. Furthermore, the short-term clinical performance of zirconia-reinforced lithium silicates and lithium-aluminium disilicates is demonstrated to be comparable to that of lithium disilicate ceramics and reveals promising potential for their long-term clinical performance.
... The present study was developed based on previous investigations claiming that the silane applied with electrical current (5), as well as the ceramic heating combined with preheating and concentrations of the hydrofluoric acid (16), can improve the bond strength of the resin cement to ceramic. Thus, this investigation verified the effect of the association preheated hydrofluoric acid/silane applied with electrical current (50µA) on the bond strength, failure types, and contact angle of the resin cement/acid-sensitive ceramic bond evaluated at 24h or after thermocycling. ...
... On the other hand, the pre-heated hydrofluoric acid (70ºC) and vitreous ceramic (85ºC) increased the resistance value with a concentration of 5%, promoting results similar to the 10% concentration of not pre-heating samples. In addition, heating at the lowest acid concentration had also a positive effect on the removal of the glassy matrix (16). Table 2 shows the failure mode values (%). ...
This study verified the effect of the combination of preheated hydrofluoric acid/silane/electric current in the adhesion of the resin cement to ceramic. IPS E.max Press ceramic discs embedded in PVC rigid tubes were divided into four groups associating preheated hydrofluoric acid and silane applied with electrical current (n=10): Ha+S (Heated acid + silane); Ha+S+Ec (Heated acid + silane + electrical current); A+S (Acid + silane) and A+S+Ec (Acid + silano + electrical current). Resin cement/ceramic samples were stored in water at 37°C for 24h. After storage, they were submitted to the microshear test, fracture analysis, and contact angle at 24h or after thermocycling (10,000 cycles/5-55ºC). Bond strength data were evaluated by two-way ANOVA. For comparison between evaluation times (24h or thermocycling) was applied unpaired t-test. A significance post-hoc test of p=0.05 was assumed for analyses and graphs (GraphPad Prism 9.0 software). At 24h, the microshear strength showed similar values between Ha+S, Ha+S+Ec, and A+S+Ec groups, while A+S showed the lowest value with a statistical difference. After thermocycling, Ha+S and Ha+S+Ec were similar, as well as A+S and A+S+Ec. There was a significant difference in all groups comparing 24h (highest value) with after thermocycling (lowest value). Adhesive fracture was predominant in all groups and evaluation times. Ha+S and A+S groups showed higher contact angle values compared to the Ha+S+Ec and A+S+Ec with lower values. In conclusion, the association of preheated hydrofluoric acid/silane applied or not with electric current promoted different microshear strength values, fracture types, and contact angles in the resin cement/ceramic bond.
... For complete polymerization, the specimens were immersed in distilled water and incubated at 37°C for 24 hours. [17] Thermocycling To better simulate the clinical oral environment, all specimens were immersed in distilled water at 37°C for 7 days and underwent 2000 thermal cycles between 5 and 55°C with an exposure time of 20 seconds and a transfer time of 5-10 seconds according to ISO-11405 2003. [1,18] ...
Background
This study assessed the effect of combined application of hydrofluoric (HF) acid and phosphoric acid (PA) and active irrigation (AI) with a microbrush on shear bond strength (SBS) of lithium disilicate (LDS) ceramics to enamel.
Materials and Methods
This in vitro study was conducted on 40 extracted teeth that received enamel preparation with a #12 cylindrical bur. Forty IPS e.max LT rods (3mm diameter, 6mm height) were fabricated and randomly assigned to four groups (n = 10) for surface treatment with 5% HF (group 1), 5% HF and AI with a microbrush for 20 seconds (group 2), 5% HF and 32% PA (group 3), and 5% HF and 32% PA plus AI with a microbrush for 20 seconds (group 4). Silane and Choice 2 cement were used for bonding rods to enamel. The SBS was measured by a universal testing machine. Data were analyzed by two-way analysis of variance (ANOVA), Bonferroni, and Chi-square tests (alpha = 0.05).
Results
Group 4 had the highest SBS, and group 1 had the lowest SBS ( P < 0.05). Group 2 had a significantly higher SBS than group 1, and group 4 had a significantly higher SBS than group 3. AI with a microbrush significantly increased the SBS ( P < 0.05), but the application of PA caused no significant change in SBS ( P > 0.05). The interaction effect of PA and AI on SBS was not significant ( P > 0.05).
Conclusion
The application of PA in addition to 5% HF acid caused no significant change in the SBS of LDS ceramic to enamel. However, AI with a microbrush significantly increased the SBS.
... Surface treatment with hydrofluoric acid is used on glass-ceramics to promote strong, stable adhesive bonding in indirect restorations. 7,9,20,24,30,34,44,50,54,56,58,61,63 This systematic review and meta-analysis of in-vitro studies compared the efficacy of glass-ceramic surface treatment with lower-concentration HF (<5%) etchants to that of higher-concentration HF (>5%) etchants. There were no statistically significant differences between treatments with low (4%-5%) and high (7%-10%) HF concentrations in short-term evaluations. ...
... 9,42 The present meta-analysis compared the standardized mean difference among bond strengths derived from different bond strength tests, resulting in high data heterogeneity, as reported by other studies. 39,67 Several aging methods were analyzed: storage for 24 h (most common), 9,20,45,50,54,56 6 months, 57 or 90 days; 33 and thermocycling for 12,000 7,61 or 10,000 24,63 cycles. Unfortunately, methodological heterogeneity in storage and thermocycling conditions prohibited a metaanalysis, and further studies are needed regarding the impact of aging methods on bond strength to glass-ceramics. ...
Purpose:
To conduct a systematic review and meta-analysis of in-vitro bond strength to glass-ceramics using hydrofluoric acid (HF) at lower (<5%) and higher (>5%) concentrations ([HF]) to treat ceramic surfaces.
Methods:
Systematic searches were carried out in PubMed, Scopus, LILACS, and Web of Science for articles published through July 2021, and a meta-analysis was performed to estimate the combined effect by comparing the differences between the standardized means of the bond strengths of the evaluated materials.
Results:
In total, 943 articles were found, of which 17 studies were selected for qualitative analysis and 12 for quantitative analysis. The bond strength to glass-ceramics using 4% to 5% HF did not differ from that using 7% to 10% HF for the following HF etching times and glass-ceramic materials: 20 s for lithium-disilicate (Z = 0.65, p = 0.51), 60 s for feldspathic (Z = 0.53, p = 0.60), and 60 s for leucite (Z = 0.72, p = 0.35).
Conclusion:
The lower concentration HF (<5%) etchant is a reliable surface treatment for adhesive bonding to glass-ceramics with satisfactory bond strength in short-term evaluations.
... Different HF etching regimens have been studied in the literature with the etching duration as the most common experimental factor [15,26,58]. Moreover, effects of the temperature and concentration of ceramic acid etchants have been explored [59][60][61]. In the present study, irrespective of the executed etching protocol, HF resulted in significant topographical alterations seen in the form of nanoporosities, striations and grooves within the etched intaglio ceramic surface (Fig. 2). ...
Objectives:
To investigate the effect of different surface treatments on optical, topographical and mechanical properties of CAD/CAM lithium silicate-based glass ceramics (LSC's) and their combined effect on the output of a light curing unit (LCU).
Methods:
Four CAD/CAM LSC's were investigated: Lithium Disilicate (Emax CAD; EC), Zirconia-reinforced silicates (Vita Suprinity; VS and Celtra Duo;CD) and Lithium Aluminum Disilicate (CEREC Tessera; CT). Ceramic specimens (n = 240) were divided into six subgroups according to their surface treatment: (a) Control, (b) Hydrofluoric acid (HF) 5%, (c) HF 5% + Neutralizing agent (N), (d) HF 9%, (e) HF 9% +N and (f) Self-etching ceramic primer (SEP). Irradiance, power and radiant exposure of a LCU were measured with MARC-LC following ceramic specimen interposition. Direct light transmission (T%) and absorbance (Abs%) of the specimens were measured with UV-Vis spectrophotometry. Roughness (Sa, Sq) and wettability (θ°) were measured with optical profilometry and sessile drop profile analysis, respectively. Biaxial flexural strength (σ) of the ceramic specimens was measured by the ball-on-three-balls method and ceramic specimens were examined microscopically. Statistical analyses was performed by two-way ANOVA followed by post hoc multiple comparisons (α = 0.05).
Results:
Acid neutralization decreased T% and increased Abs% in all LSC's and highest T% was exhibited with VS. Neutralized EC, VS and CD displayed higher Sa in HF9, while neutralized CT displayed higher Sa in HF5. Self-etch primer significantly reduced θ° (p < 0.001). σ was observed in the followed ascending order: HF9 +N < HF9 < HF5 +N < HF5 < SEP < Control for all LSC's.
Significance:
Optical, topographical and mechanical properties of the CAD/CAM ceramic blocks were strongly dependent on the type of surface treatment. Results of neutralization post-etching indicate promising potential for future investigations.
... The use of silane appears to be critical for the bond's durability, according to many in vitro experiments. 29,30 In the case of Vita Enamic, the findings revealed that the simplified approach utilising MEP recorded much higher SBS mean values than the standard technique (HF+S). These are the outcomes of Murillo-Gómez and De Goes' research (2019) 31 This didn't match the findings of previous investigations. ...
Aim: The goal of this work was to compare the shear bond strength of various ceramics bonded to tooth structure following thermocycling using a traditional versus a simplified Surface Treatment. Materials and methods: Thirty removed human mandibular molar teeth were separated into three groups (n=10) based on the type of ceramic material employed (zirconia reinforcing lithium silicate (Celtra duo), Polymer infiltrated glass ceramic (Vita enamic), and lithium disilicate ceramic (IPS E Max cad)). Each group was divided into two categories based on the surface treatment process (n=5) The classic approach (hydrofluoric acid with silane coupling agent) was used in Subgroup I, whereas the simplified method was applied by using Monobond Etch & Prime(MEP) in Subgroup II. Ceramic discs were cemented to tooth structure using self-adhesive dual cure resin cement. Shear bond strength test (SBS) was carried out using universal testing machine. The data was obtained, processed, and statistically analyzed. Results: It was found that a significant higher SBS mean values recorded for conventional technique in IPS Emax cad and Celtra duo group (12.57±0.51, 11.46±0.51MPa) than that in simplified technique (11.41±0.36, 7.32±0.75) respectively. While in Vita Enamic group there was significantly higher SBS mean values recorded for the simplified technique (10.83±0.17) using MEP than conventional technique (8.24±0.46) using hydrofluoric acid with silane coupling agent. Conclusion: Vita Enamic showed better results using Monobond Etch & Prime surface treatment than HF acid and silane. While For Emax and celtra due HF acid and silane surface treatment has shown better results.
... Previous studies have shown proper adhesive resistance when the ceramic is conditioned for 60-120 s with 9.6%-10% HF acid for feldspathic ceramics [23][24][25][26]. Two studies have concluded that 5% HF acid etching was not able to produce proper micro-mechanical retention between the ceramic and the resin cement for lithium-disilicate ceramics, resulting in a lower resistance when compared to 10% HF acid etching [12,27]. Moreover, flexural strength of a lithium disilicate ceramic decreased when exposed to 4.9% HF acid for longer than 20 s [28]. ...
Statement of problem
The process prior to cementing a glass ceramic requires that the surface be etched with hydrofluoric acid in order to improve its adhesion. HF acid concentration and conditioning time can influence the shape and size of the micro retentions created on the ceramic surface, and consequently both reflect on the bond strength to the cementing agent and on the mechanical behavior of the material.
Purpose
This study systematically reviewed the literature to compare the effect of alternative vs. manufacturer-recommended hydrofluoric (HF) acid etching time and concentrations on the adhesive and mechanical behavior of feldspathic (FEL), leucite-reinforced (LEU), lithium disilicate (LD), and lithium silicate (LS) glass-ceramics.
Material and methods
Searches were performed in the PubMed/Medline, Scopus, LILACS, and Web of Science databases. The search strategy was independently carried out in two steps (title and abstract reading, and full-text reading) by two reviewers. The in vitro studies had to include at least one manufacturer-recommended protocol group (comparison) and one alternative HF acid concentration or etching time (intervention). Meta-analyses were carried out separately for each ceramic (FEL/LEU or LD/LS), outcome (bond or flexural strength), test condition (baseline or after aging), and analyzed factor (HF acid etching time or concentration).
Results
A total of 86 from 3375 relevant studies were selected for full-text analysis, 28 were included for qualitative synthesis, from which 20 were used in the meta-analysis. Baseline and aging meta-analyses for bond strength of FEL/LEU showed no significant effect of HF concentration and no significant effect of HF etching time (at baseline). Meta-analyses showed that <5%HF acid (20s) and etching for more than 20 s (5% or 10%HF acid) decreases the baseline bond strength of LD/LS. No significant difference was observed after aging. In addition, HF acid etching with concentrations above 5% (20s) or for more than 20 s (5%HF acid) reduces the flexural strength of LD/LS.
Conclusions
The manufacturer-recommended protocol of hydrofluoric acid etching (5% for 20 s) is the most efficient regarding bond and flexural strength of LD/LS. HF acid etching time and concentration do not seem to affect the bond strength of FEL/LEU, but there is a lack of studies on the effect of etching protocols on their mechanical behavior.
... 3,[6][7][8] For optimal bonding performance to lithium disilicate glass ceramics, the surfaces are etched with hydrofluoric acid (5-10%) to create a rough surface by dissolving the glassy matrix, increasing surface area and surface energy, which increases the wetting by polymeric materials. [8][9][10][11][12][13] In addition, a silane coupling agent is applied to ensure chemical interaction between the silica and methacrylate groups of the resin luting agent or bonding resin. [14][15][16] The association of hydrofluoric acid etching followed by silane application is the most adopted intaglio surface treatment of glass ceramics since it results in high bond strength values. ...
Objectives:
To evaluate the bond strength of a resin luting agent to a lithium disilicate glass-ceramic after the use of different fit-checking materials and cleaning protocols.
Methods and materials:
Two hundred and forty-two (242) ceramic specimens were etched with 5% hydrofluoric acid for 20 seconds and distributed into 22 groups (n=10), in total. Four (4) groups were created based on fit-checking material and that had no following cleaning protocol: no fit-checking material used (control group); articulating paper; articulating spray; and fit-checker liquid. For each fit-checking material (3), 6 cleaning protocols were tested creating an additional 18 groups (n=10): air/water spray; 70% alcohol (ethanol); acetone; 35% phosphoric acid; 5% hydrofluoric acid; and a commercially available cleaning paste (Ivoclean, Ivoclar Vivadent). Silane and bonding resin were applied to all ceramic surfaces. Resin luting agent cylinders (1 mm in diameter) were created using silicone matrices, light-cured, and specimens were stored in deionized water at 37°C for 24 hours. Microshear bond strength test (μSBS) was performed on a universal testing machine (DL 500, EMIC) at a crosshead speed of 1 mm/min until failure. Results were statistically analyzed using ANOVA and Tukey's test (α=0.05).
Results:
Articulating paper and fit-checker liquid, when not properly removed, negatively affected the bond strength (p<0.05). None of the tested cleaning protocols were effective for articulating paper (p<0.05). There was no significant difference in bond strength after the cleaning protocols between articulating spray and fit-checker liquid when compared to the control group (no contamination) (p>0.05).
Conclusion:
The cleaning protocols tested can effectively restore the bond strength of resin luting agents to lithium disilicate ceramics that were exposed to articulating spray or fit-checker liquid. The use of articulating paper is not recommended for fit-checking indirect lithium disilicate restorations.
... The use of silane appears to be critical for the bond's durability, according to many in vitro experiments. 29,30 In the case of Vita Enamic, the findings revealed that the simplified approach utilising MEP recorded much higher SBS mean values than the standard technique (HF+S). These are the outcomes of Murillo-Gómez and De Goes' research (2019). ...
... Furthermore, investigations examined various exterior surface techniques in terms of polishing, glazing, and coating. Exclusion criteria were studies on: (1) Zirconia; (2) Intra-radicular posts; (3) Implant superstructure; (4) Polycrystalline ceramics. ...
Objectives: Glass matrix and resin matrix ceramic materials has gained popularity in recent years, which has increased their clinical use. The purpose of this scientific overview is to discuss the impact of existing internal and external surface treatment procedures, as well as their potential consequences. Study Selection, Data and Sources: The recent literature of in vitro research investigating adhesion methods and external surface techniques on both glass matrix and resin matrix ceramics, including studies from 2014 until 2020, was considered. A search of Eng-lish language studies was carried out using Pubmed, MEDLINE, and Google scholar. Results: A total of ninety-seven publications were recognized for evaluation. Several surface treatment techniques with different testing approaches were reviewed and categorized in this review according to the surface modification method: internal surface treatments including mechanical bonding, chemical etching, and external surface treatments including glazing and polishing. Conclusions: With respect to the diversity of the included studies, their results were difficult to compare in that the factors varied in each research protocol. This was considered a limitation for this review to recommend a final surface treatment protocol for each material. However, most of the studies reported hydrofluoric acid (HF) as the most effective in glass matrix ceramics internal surface treatment. Increasing the concentration and etching duration maximizes the etching effect. For resin matrix ceramics, air particle abrasion and hydrofluoric acid etching have been widely accepted as micro-mechanical internal surface treatment protocols. The merits of various glazing and polishing surface treatment systems for the two ceramic materials were also debated in other studies. Depending on the ceramic microstructure, exterior surface investigations favoured one approach over the other. A final recommended protocol, however, has not yet been authorized.
