Effect of acid etching on the flexural strength of a feldspathic porcelain and a castable glass ceramic

The aim of this study was to examine the effect of different acid etching times on the surface roughness and flexural strength of a lithium disilicate-based glass ceramic. Ceramic bar-shaped specimens (16 mm x 2 mm x 2 mm) were produced from ceramic blocks. All specimens were polished and sonically cleaned in distilled water. Specimens were randomly divided into 5 groups (n=15). Group A (control) no treatment. Groups B-E were etched with 4.9% hydrofluoric acid (HF) for 4 different etching periods: 20 s, 60 s, 90 s and 180 s, respectively. Etched surfaces were observed under scanning electron microscopy. Surface profilometry was used to examine the roughness of the etched ceramic surfaces, and the specimens were loaded to failure using a 3-point bending test to determine the flexural strength. Data were analyzed using one-way ANOVA and Tukey's test (?=0.05). All etching periods produced significantly rougher surfaces than the control group (p<0.05). Roughness values increased with the increase of the etching time. The mean flexural strength values were (MPa): A=417 ± 55; B=367 ± 68; C=363 ± 84; D=329 ± 70; and E=314 ± 62. HF etching significantly reduced the mean flexural strength as the etching time increased (p=0.003). In conclusion, the findings of this study showed that the increase of HF etching time affected the surface roughness and the flexural strength of a lithium disilicate-based glass ceramic, confirming the study hypothesis.

Download Full-text

Hard machining, glaze firing and hydrofluoric acid etching: Do these procedures affect the flexural strength of a leucite glass–ceramic?

Dental Materials ◽

10.1016/j.dental.2015.04.005 ◽

2015 ◽

Vol 31 (7) ◽

pp. e131-e140 ◽

Cited By ~ 24

Author(s):

Sara Fraga ◽

Luiz F. Valandro ◽

Marco A. Bottino ◽

Liliana G. May

Keyword(s):

Flexural Strength ◽

Glass Ceramic ◽

Hydrofluoric Acid ◽

Acid Etching ◽

Hard Machining

Download Full-text

Factors Affecting the Wear Behavior of Monolithic Zirconia and the Antagonists: Literature Review

Current Dentistry ◽

10.2174/2542579x02666200206111259 ◽

2020 ◽

Vol 2 (1) ◽

pp. 4-11

Author(s):

Marcia Borba ◽

Paula Benetti ◽

Giordana P. Furini ◽

Kátia R. Weber ◽

Tábata M. da Silva

Keyword(s):

Literature Review ◽

Glass Ceramic ◽

Wear Behavior ◽

Glass Ceramics ◽

Surface Treatments ◽

Human Tooth ◽

Initial Surface ◽

Monolithic Zirconia ◽

Feldspathic Porcelain

Background: The use of zirconia-based ceramics to produce monolithic restorations has increased due to improvements in the optical properties of the materials. Traditionally, zirconiabased ceramics were veneered with porcelain or glass-ceramic and were not directly exposed to the oral environment. Therefore, there are several doubts regarding the wear of the monolithic zirconia restoration and their antagonists. Additionally, different surface treatments are recommended to promote a smooth surface, including glaze and several polishing protocols. To support the correct clinical application, it is important to understand the advantages and limitations of each surface treatment. Objective: The aim of this short literature review is to investigate the factors that may affect the wear of monolithic zirconia restorations in service and their antagonists. Methods: Pubmed/Medline database was accessed to review the literature from a 10-year period using the keywords: zirconia, monolithic, prosthesis, wear. Both clinical and in vitro studies were included in the review. Results: Studies investigated the effect of several surface treatments, including grinding with diamond- burs, polishing and glazing, on the surface roughness, phase transformation and wear capacity of monolithic zirconia. The wear behavior of monolithic zirconia was frequently compared to the wear behavior of other ceramics, such as feldspathic porcelain, lithium disilicate-based glassceramic and leucite-reinforced glass-ceramic. Human tooth, ceramics and resin composites were used as antagonist in the investigations. Only short-term clinical studies are available (up to 2 years). Conclusion: Literature findings suggest that zirconia monolithic restorations are wear resistant and unlikely to cause excessive wear to the antagonist, especially when compared to feldspathic porcelain and glass-ceramics. Monolithic zirconia should be polished rather than glazed. Yet, none of the polishing systems studied was able to completely restore the initial surface conditions of zirconia after being adjusted with burs. More clinical evidence of the antagonist tooth wear potential of monolithic zirconia is needed.

Download Full-text

Impact of Silane-containing Universal Adhesive on the Biaxial Flexural Strength of a Resin Cement/Glass-ceramic System

Operative Dentistry ◽

10.2341/17-356-l ◽

2019 ◽

Vol 44 (2) ◽

pp. 200-209 ◽

Cited By ~ 1

Author(s):

F Murillo-Gómez ◽

RB Wanderley ◽

MF De Goes

Keyword(s):

Flexural Strength ◽

Glass Ceramic ◽

Resin Cement ◽

Weibull Analysis ◽

Ceramic System ◽

Universal Adhesive ◽

Bonded Interface ◽

Biaxial Flexural Strength ◽

Digital Caliper ◽

One Way Anova

SUMMARY The aim of this study was to determine whether using a silane-containing universal adhesive as a silane primer in glass-ceramic/resin cement systems affects biaxial flexural strength (BFS) and bonded interface integrity after loading. Glass-ceramic (IPS e.max CAD, Ivoclar/Vivadent, Schaan, Liechtenstein) disc-shaped specimens (6.5±0.1mm in diameter, 0.5±0.1mm thick) were etched with 5% hydrofluoric acid (HF) for 20 seconds and divided into four groups of 30 specimens, to be treated as follows: 1) One bottle silane primer (RCP); 2) Separate application of silane and adhesive (RCP+SB); 3) Silane-containing universal adhesive (SBU); 4) No treatment (C). After silanization, all specimens were resin cement– coated and polymerized for 40 seconds. Each specimen layer was measured, as well as each assembly's thickness, using a digital caliper and scanning electron microscope (SEM). Specimens were stored for 24 hours and submitted to a BFS test (1.27 mm/min). BFS values were calculated using the bilayer disc-specimen solution. Bonded interfaces were analyzed on fractured fragments using SEM. One-way ANOVA and Tukey tests (α=0.05) were applied, as well as the Weibull analysis. Factor “silane treatment” was statistically significant (p<0.0001). RCP+SB (372.2±29.4 MPa) and RCP (364.2±29.5 MPa) produced significantly higher BFS than did the C (320.7±36.3 MPa) or SBU (338.0±27.1 MPa) groups. No differences were found in the Weibull modulus (m: RCP: 10.1-17.3; RCP+SB: 10.1-17.0; SBU: 12.3-22.4; C: 7.4-12.9). Bonded interface analysis exhibited ceramic-cement separation (SBU, C) and voids within the resin cement layer (all groups). Neither the ceramic/cement system's BFS nor its bonded interface stability were improved by SBU after loading.

Download Full-text

Acid Etching as Surface Treatment Method for Luting of Glass-Ceramic Restorations, part 1: Acids, Application Protocol and Etching Effectiveness

Open Access Macedonian Journal of Medical Sciences ◽

10.3889/oamjms.2018.147 ◽

2018 ◽

Vol 6 (3) ◽

pp. 568-573 ◽

Cited By ~ 4

Author(s):

Emilija Barjaktarova-Valjakova ◽

Anita Grozdanov ◽

Ljuben Guguvcevski ◽

Vesna Korunoska-Stevkovska ◽

Biljana Kapusevska ◽

...

Keyword(s):

Surface Treatment ◽

Glass Ceramic ◽

Hydrofluoric Acid ◽

Treatment Method ◽

Acid Etching ◽

Etching Time ◽

Ceramic Surface ◽

Adhesive Luting ◽

Ceramic Restorations ◽

Etching Effect

AIM: The purpose of this review is to represent acids that can be used as surface etchant before adhesive luting of ceramic restorations, placement of orthodontic brackets or repair of chipped porcelain restorations. Chemical reactions, application protocol, and etching effect are presented as well.STUDY SELECTION: Available scientific articles published in PubMed and Scopus literature databases, scientific reports and manufacturers' instructions and product information from internet websites, written in English, using following search terms: “acid etching, ceramic surface treatment, hydrofluoric acid, acidulated phosphate fluoride, ammonium hydrogen bifluoride”, have been reviewed.RESULTS: There are several acids with fluoride ion in their composition that can be used as ceramic surface etchants. The etching effect depends on the acid type and its concentration, etching time, as well as ceramic type. The most effective etching pattern is achieved when using hydrofluoric acid; the numerous micropores and channels of different sizes, honeycomb-like appearance, extruded crystals or scattered irregular ceramic particles, depending on the ceramic type, have been detected on the etched surfaces.CONCLUSION: Acid etching of the bonding surface of glass - ceramic restorations is considered as the most effective treatment method that provides a reliable bond with composite cement. Selective removing of the glassy matrix of silicate ceramics results in a micromorphological three-dimensional porous surface that allows micromechanical interlocking of the luting composite.

Download Full-text

Effect of silane and resin-cement on flexural strength of glass-ceramic

Dental Materials ◽

10.1016/j.dental.2016.08.030 ◽

2016 ◽

Vol 32 ◽

pp. e15-e16

Author(s):

F. Murillo-Gómez ◽

R.B.W. Lima ◽

M.F. De Goes

Keyword(s):

Flexural Strength ◽

Glass Ceramic ◽

Resin Cement

Download Full-text

Improving shear bond strength between feldspathic porcelain and zirconia substructure with lithium disilicate glass-ceramic liner

Dental Materials Journal ◽

10.4012/dmj.2014-319 ◽

2015 ◽

Vol 34 (3) ◽

pp. 302-309 ◽

Cited By ~ 5

Author(s):

Kamolporn WATTANASIRMKIT ◽

Viritpon SRIMANEEPONG ◽

Kanchana KANCHANATAWEWAT ◽

Naruporn MONMATURAPOJ ◽

Pasutha THUNYAKITPISAL ◽

...

Keyword(s):

Bond Strength ◽

Glass Ceramic ◽

Shear Bond Strength ◽

Lithium Disilicate ◽

Ceramic Liner ◽

Feldspathic Porcelain

Download Full-text

Effect of the bur grit size on the flexural strength of a glass-ceramic

Cerâmica ◽

10.1590/0366-69132016623621988 ◽

2016 ◽

Vol 62 (362) ◽

pp. 121-127 ◽

Cited By ~ 1

Author(s):

P. P. Kist ◽

I. L. Aurélio ◽

M. Amaral ◽

L. G. May

Keyword(s):

Surface Roughness ◽

Flexural Strength ◽

Glass Ceramic ◽

Glass Ceramics ◽

Internal Surface ◽

Grit Size ◽

Diamond Grit ◽

Cad Cam ◽

Negative Effect ◽

Ceramic Blocks

Abstract The purpose of the present study was to determine the biaxial flexural strength (BFS) of a CAD/CAM leucite reinforced glass-ceramic ground by diamond burs of different grit sizes and the influence of surface roughness on the BFS. For this, 104 plates were obtained from CAD/CAM ceramic blocks and divided into 4 groups (n = 26), according to bur grit size: extra-fine, fine, medium and coarse. Roughness parameters (Ra, RyMax) were measured, and plates were kept dry for 7 days. The flexural test was carried out and BFS was calculated. Ra, RyMax and BFS data were subjected to analysis of variance and post-hoc test. Weibull analysis was used to compare characteristic strength and Weibull modulus. Regression analysis was performed for BFS vs. Ra and RyMax. When burs with coarse grit were used, higher surface roughness values were found, causing a negative effect on the ceramic BFS (117 MPa for extra-fine, and 83 MPa for coarse). Correlation (r) between surface roughness and BFS was 0.78 for RyMax and 0.73 for Ra. Increases in diamond grit size have a significant negative effect on the BFS of leucite-reinforced glass-ceramics, suggesting that grinding of sintered glass-ceramic should be performed using burs with the finest grit possible in order to minimize internal surface flaws and maximize flexural strength.

Download Full-text