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Krüger S, Wille S, Kern M. The Correlation of Surface Roughness Parameters of Zirconia and Lithium Disilicate with Steatite Wear. J Prosthodont 2023; 32:e52-e63. [PMID: 35771977 DOI: 10.1111/jopr.13562] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2022] [Accepted: 06/14/2022] [Indexed: 11/30/2022] Open
Abstract
PURPOSE Various surface roughness parameters are utilized to describe the surface in the tooth to ceramics abrasion and to assess the resulting wear. The use of three-dimensional parameters may offer a better estimation for wear and an improved deduced clinical surface treatment. The aim of this study was to determine the influence of various surface roughness parameters of zirconia and lithium disilicate ceramics on the wear of steatite antagonists. MATERIAL AND METHODS Forty zirconia specimens with a diameter of 7 mm and a thickness of 3 mm and 40 lithium disilicate specimens with the dimensions 10×10×4 mm were each divided into five subgroups. Two subgroups were treated with different clinically established diamond burs; a third subgroup was treated with a silicone polishing set. Two additional subgroups were produced by glazing the surfaces after treatment. Surface roughness parameters were determined by laser scanning microscopy. All specimens underwent 1.2 million loading cycles using steatite antagonists. After regular intervals of cycles, precision impressions were made to assess the wear. The correlation between wear and different roughness parameters was evaluated using the Spearman correlation test. RESULTS For the glazed zirconia, unglazed zirconia, and glazed lithium disilicate specimens no significant correlations (p > 0.05) between the investigated roughness parameters and antagonist wear could be found. In the unglazed lithium disilicate groups, significant (p ≤ 0.05) correlations with steatite substance loss could be found for several roughness parameters after 1.2 million cycles. CONCLUSIONS For lithium disilicate, it seems not sufficient to use only one roughness parameter to indicate the wear behavior of the surface. There was no correlation between wear and the tested roughness parameters of zirconia surfaces.
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Affiliation(s)
- Stephan Krüger
- Department of Prosthodontics, Propaedeutics and Dental Materials, School of Dentistry, Christian-Albrechts University, Kiel, Germany
| | - Sebastian Wille
- Department of Prosthodontics, Propaedeutics and Dental Materials, School of Dentistry, Christian-Albrechts University, Kiel, Germany
| | - Matthias Kern
- Department of Prosthodontics, Propaedeutics and Dental Materials, School of Dentistry, Christian-Albrechts University, Kiel, Germany
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Baldi A, Carossa M, Comba A, Alovisi M, Femiano F, Pasqualini D, Berutti E, Scotti N. Wear Behaviour of Polymer-Infiltrated Network Ceramics, Lithium Disilicate and Cubic Zirconia against Enamel in a Bruxism-Simulated Scenario. Biomedicines 2022; 10:biomedicines10071682. [PMID: 35884986 PMCID: PMC9313215 DOI: 10.3390/biomedicines10071682] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2022] [Revised: 07/08/2022] [Accepted: 07/11/2022] [Indexed: 11/16/2022] Open
Abstract
The present study aimed to evaluate the wear rate of polymer-infiltrated network composites and ceramics against enamel in a bruxism-simulated scenario. Ninety-six (n = 96) molars were divided into six groups (n = 16) according to their occlusal material: group 1—a polymer-infiltrated network ceramic (PINC); group 2—a second polymer-infiltrated network ceramic (PINC2); group 3—nanohybrid resin-based composite (CO); group 4—cubic zirconia (ZR); group 5—lithium disilicate (LS); and group 6—sound enamel (EN). A laser scanner was used to digitalize all of the occlusal surfaces before and after a fatigue test, which was conducted with a chewing simulator set at 80 N and semicircular movement in order to simulate bruxist movement and loads. Statistical analysis of volume loss was performed with a one-way ANOVA and post hoc Bonferroni test. ZR had significantly inferior wear to PINC (p ≤ 0.01) and CO (p = 0.04). LS wore the antagonist enamel significantly more than PINC, CO, PINC2 and EN (p ≤ 0.01). On the other hand, ZR wore the antagonist enamel significantly more than CO (p ≤ 0.01) and PINC2 (p = 0.05). In conclusion, PINCs better preserved antagonist enamel at the expense of a higher wear of their own. LS causes significantly higher enamel wear compared with PINCs. ZR caused significantly higher enamel wear compared with CO and PINC2, but it was wear-resistant.
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Affiliation(s)
- Andrea Baldi
- Department of Surgical Sciences, CIR Dental School, University of Turin, Via Nizza 230, 10126 Turin, Italy; (A.B.); (A.C.); (M.A.); (D.P.); (E.B.); (N.S.)
| | - Massimo Carossa
- Department of Surgical Sciences, CIR Dental School, University of Turin, Via Nizza 230, 10126 Turin, Italy; (A.B.); (A.C.); (M.A.); (D.P.); (E.B.); (N.S.)
- Correspondence:
| | - Allegra Comba
- Department of Surgical Sciences, CIR Dental School, University of Turin, Via Nizza 230, 10126 Turin, Italy; (A.B.); (A.C.); (M.A.); (D.P.); (E.B.); (N.S.)
| | - Mario Alovisi
- Department of Surgical Sciences, CIR Dental School, University of Turin, Via Nizza 230, 10126 Turin, Italy; (A.B.); (A.C.); (M.A.); (D.P.); (E.B.); (N.S.)
| | - Felice Femiano
- Restorative Dentistry, Multidisciplinary Department of Medical-Surgical and Dental Specialties, University of Study of Campania, “Luigi Vanvitelli”, Via De Crecchio 6, 83138 Naples, Italy;
| | - Damiano Pasqualini
- Department of Surgical Sciences, CIR Dental School, University of Turin, Via Nizza 230, 10126 Turin, Italy; (A.B.); (A.C.); (M.A.); (D.P.); (E.B.); (N.S.)
| | - Elio Berutti
- Department of Surgical Sciences, CIR Dental School, University of Turin, Via Nizza 230, 10126 Turin, Italy; (A.B.); (A.C.); (M.A.); (D.P.); (E.B.); (N.S.)
| | - Nicola Scotti
- Department of Surgical Sciences, CIR Dental School, University of Turin, Via Nizza 230, 10126 Turin, Italy; (A.B.); (A.C.); (M.A.); (D.P.); (E.B.); (N.S.)
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Zhang Z, Wang Q, Wang F, Li D, Meng M, Zhang Y, Zhang S. Effect of aqueous environment on wear resistance of dental glass-ceramics. BMC Oral Health 2022; 22:143. [PMID: 35473925 PMCID: PMC9044826 DOI: 10.1186/s12903-022-02183-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2022] [Accepted: 04/15/2022] [Indexed: 11/29/2022] Open
Abstract
Background Wear resistance affects dental ceramics longevity and the functions of the opposing teeth. However, data for the effect of aqueous environment on wear resistance of dental ceramics are lacking. This study evaluated the effect of aqueous environment on wear resistance of typical dental glass–ceramics. Methods Disk specimens were prepared from lithium disilicate glass–ceramics (LD) and leucite reinforced glass–ceramics (LEU). The disk specimens paired with steatite antagonists were tested in a pin-on-disk tribometer under both wet and dry conditions with 10 N up to 500,000 wear cycles. The wear analysis of glass–ceramics was performed using a 3D profilometer after 100,000, 300,000 and 500,000 wear cycles. Wear morphologies were analyzed by employing scanning electron microscopy (SEM). The crystalline compositions of specimens stored in a dry environment and subsequently immersed in distilled water for 40 h were separately determined using X-ray diffraction (XRD). The chemical states of the wear surfaces for LD were analyzed by X-ray photoelectron spectroscopy (XPS). The data analysis and multiple pair-wise comparisons of means were performed by using one-way analysis of variance (ANOVA) and Tukey’s post-hoc test. Results LEU in a wet environment exhibited less wear volume loss than that in a dry environment (p < 0.05). The volume loss of LD in a wet environment was higher than that in a dry environment (p < 0.05). The wear volumes of steatite antagonists paired with two glass–ceramics under dry conditions were higher than under wet conditions. Conclusions XPS spectra of LD under wet conditions indicated that high wear loss might result from the effect of stress corrosion by water and reaction of water with the ionic-covalent bonds at the crack tip. XPS spectra and SEM images of LD under dry conditions showed a possible formation of tribofilm. Within the limitations of this in vitro study, water was wear-friendly to LEU and all opposing steatites but aggravated wear for LD.
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Affiliation(s)
- Zhenzhen Zhang
- State Key Laboratory of Military Stomatology and National Clinical Research Center for Oral Diseases and Shaanxi Key Laboratory of Oral Diseases, Department of Prosthodontics, School of Stomatology, Fourth Military Medical University, Changle Xi Road 145, Xi'an, 710032, Shaanxi, China
| | - Qi Wang
- State Key Laboratory of Military Stomatology and National Clinical Research Center for Oral Diseases and Shaanxi Key Laboratory of Oral Diseases, Department of Pediatric Dentistry, School of Stomatology, Fourth Military Medical University, Xi'an, 710032, Shaanxi, China
| | - Fu Wang
- State Key Laboratory of Military Stomatology and National Clinical Research Center for Oral Diseases and Shaanxi Key Laboratory of Oral Diseases, Department of Prosthodontics, School of Stomatology, Fourth Military Medical University, Changle Xi Road 145, Xi'an, 710032, Shaanxi, China
| | - Ding Li
- School of Science, Xi'an University of Posts and Telecommunications, Xi'an, 710121, Shaanxi, China
| | - Meng Meng
- State Key Laboratory of Military Stomatology and National Clinical Research Center for Oral Diseases and Shaanxi Key Laboratory of Oral Diseases, Department of Prosthodontics, School of Stomatology, Fourth Military Medical University, Changle Xi Road 145, Xi'an, 710032, Shaanxi, China
| | - Yaming Zhang
- School of Science, Xi'an University of Posts and Telecommunications, Xi'an, 710121, Shaanxi, China
| | - Shaofeng Zhang
- State Key Laboratory of Military Stomatology and National Clinical Research Center for Oral Diseases and Shaanxi Key Laboratory of Oral Diseases, Department of Prosthodontics, School of Stomatology, Fourth Military Medical University, Changle Xi Road 145, Xi'an, 710032, Shaanxi, China.
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Zaniboni JF, Silva AM, Alencar CDM, Porto TS, Jasinevicius RG, Fortulan CA, de Campos EA. Influence of different glaze firing protocols on the mechanical properties of CAD-CAM ceramic materials. J Prosthet Dent 2022; 127:925.e1-925.e8. [DOI: 10.1016/j.prosdent.2022.03.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2021] [Revised: 03/08/2022] [Accepted: 03/09/2022] [Indexed: 11/27/2022]
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Tokunaga J, Ikeda H, Nagamatsu Y, Awano S, Shimizu H. Wear of Polymer-Infiltrated Ceramic Network Materials against Enamel. MATERIALS 2022; 15:ma15072435. [PMID: 35407767 PMCID: PMC8999962 DOI: 10.3390/ma15072435] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/25/2022] [Revised: 03/16/2022] [Accepted: 03/23/2022] [Indexed: 12/25/2022]
Abstract
Polymer-infiltrated ceramic network materials (PICNs) have high mechanical compatibility with human enamel. However, the wear properties of PICN against natural human enamel have not yet been clarified. We investigated the in vitro two-body wear behaviors of PICNs and an enamel antagonist. Two PICNs were used: Experimental PICN (EXP) prepared via the infiltration of methacrylate-based resin into the porous silica ceramic network and commercial Vita Enamic (ENA). Two commercial dental ceramics, lithium disilicate glass (LDS) and zirconia (ZIR), were also characterized, and their wear performance was compared to PICNs. The samples were subjected to Vickers hardness tests and two-body wear tests that involve the samples being cyclically impacted by enamel antagonists underwater at 37 °C. The results reveal that the Vickers hardness of EXP (301 ± 36) was closest to that of enamel (317 ± 17). The volumetric wear losses of EXP and ENA were similar to those of LDS but higher than that of zirconia. The volumetric wear loss of the enamel antagonist impacted against EXP was moderate among the examined samples. These results suggest that EXP has wear behavior similar to that of enamel. Therefore, PICNs are mechanically comparable to enamel in terms of hardness and wear and are excellent tooth-restoration materials.
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Affiliation(s)
- Jumpei Tokunaga
- Division of Biomaterials, Department of Oral Functions, Kyushu Dental University, Fukuoka 803-8580, Japan; (J.T.); (Y.N.); (H.S.)
- Division of Clinical Education Development and Research, Department of Oral Functions, Kyushu Dental University, Fukuoka 803-8580, Japan;
| | - Hiroshi Ikeda
- Division of Biomaterials, Department of Oral Functions, Kyushu Dental University, Fukuoka 803-8580, Japan; (J.T.); (Y.N.); (H.S.)
- Correspondence:
| | - Yuki Nagamatsu
- Division of Biomaterials, Department of Oral Functions, Kyushu Dental University, Fukuoka 803-8580, Japan; (J.T.); (Y.N.); (H.S.)
| | - Shuji Awano
- Division of Clinical Education Development and Research, Department of Oral Functions, Kyushu Dental University, Fukuoka 803-8580, Japan;
| | - Hiroshi Shimizu
- Division of Biomaterials, Department of Oral Functions, Kyushu Dental University, Fukuoka 803-8580, Japan; (J.T.); (Y.N.); (H.S.)
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Qualitative Evaluation of the Effects of Professional Oral Hygiene Instruments on Prosthetic Ceramic Surfaces. MATERIALS 2021; 15:ma15010021. [PMID: 35009166 PMCID: PMC8746060 DOI: 10.3390/ma15010021] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/02/2021] [Revised: 12/20/2021] [Accepted: 12/20/2021] [Indexed: 01/01/2023]
Abstract
During professional hygiene procedures, different instruments used may cause various damage to dental prostheses. Deplaquing and scaling with curettes and ultrasonic instruments may inadvertently increase the surface roughness of the material and the risk of future bacterial adhesion and/or also compromise the marginal seal of the prosthesis. Hence, the aim of this study was to assess the qualitative effects of two types of curettes and one piezoelectric instrument with a stainless-steel tip on three types of metal-free samples. After treating the samples with different instrumentations, they were analyzed using the scanning electron microscope and then underwent a qualitative microanalysis by using a spectroscopy machine. All the materials tested in this study have undergone significant changes of their superficial structure after instrumentation both with mechanical and manual instruments. Plastic curettes appeared to be less aggressive than the other instruments. Disilicate samples show a significantly lower degree of surface glazing erosion compared to the zirconia sample with all the instruments used.
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Alao AR, Mohd Azhari MA. Investigation of indentation size effect and R-curve behaviour of Li 2O-SiO 2 and Li 2O-2SiO 2 glass ceramics. J Mech Behav Biomed Mater 2021; 124:104842. [PMID: 34555624 DOI: 10.1016/j.jmbbm.2021.104842] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2021] [Revised: 09/14/2021] [Accepted: 09/15/2021] [Indexed: 11/26/2022]
Abstract
Indentation size effect (ISE) and R-curve behaviour of Li2O-SiO2 and Li2O-2SiO2 glass ceramics are investigated using micro-indentation and indentation-strength (IS) techniques, respectively. Vickers micro-indentations were applied on both materials at the load of 0.10-19.6 N to determine the load influence on the measured hardness. For the IS-measured fracture toughness, the load ranged from 1.96 to 19.6 N. The hardness decreased with increasing load by 20% and 18% on Li2O-SiO2 and Li2O-2SiO2 glass ceramics, respectively, indicating the ISE behaviour on both materials. The fracture toughness increased with the load by 27% and 59% on Li2O-SiO2 and Li2O-2SiO2 glass ceramics, respectively, signifying the R-curve behaviour. The ISE behaviour of both materials was analysed using the Meyer's, Hays-Kendall (HK), proportional specimen resistance (PSR), Nix-Gao (NG), modified PSR (MPSR) and elastic plastic deformation (EPD) models while the R-curve behaviour was analysed by the fractional power law. The Meyer's index of both materials was less than 2, strongly confirming the ISE existence. The HK, PSR and NG models were only suitable to determine intrinsic Vickers hardness for Li2O-2SiO2 glass ceramic while the MPSR and EPD models were successful for both materials. The fractional power law gave higher R-curve steepness for Li2O-2SiO2 than Li2O-SiO2 glass ceramics. Also, material and brittleness indices predicted, respectively, higher quasi-plasticity and better machinability for Li2O-2SiO2 than Li2O-SiO2 glass ceramics indicating superior performance in the former to the latter. Finally, this study presents a new significant insight into the micro-mechanisms of fracture tolerance behaviour of these glass ceramics which is critical to their functional performance as structural ceramics.
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Affiliation(s)
- Abdur-Rasheed Alao
- Mechanical Engineering Programme Area, Faculty of Engineering, Universiti Teknologi, Brunei, Gadong, BE1410, Brunei Darussalam.
| | - Mohd Azmir Mohd Azhari
- Faculty of Manufacturing Engineering, Universiti Malaysia Pahang, 26600, Pekan, Pahang, Malaysia
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Effects of surface roughness on the time-dependent wear performance of lithium disilicate glass ceramic for dental applications. J Mech Behav Biomed Mater 2021; 121:104638. [PMID: 34171718 DOI: 10.1016/j.jmbbm.2021.104638] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Revised: 05/31/2021] [Accepted: 06/05/2021] [Indexed: 11/21/2022]
Abstract
OBJECTIVES Purpose of the present study was to evaluate the effect of surface roughness on the time-dependent wear performance of lithium disilicate (LD) glass-ceramic. METHODS Friction pairs (pin and disk specimens) were prepared by IPS e.max® Press lithium disilicate glass-ceramic. The lateral faces of friction pairs (N = 12) were grinded with silicon carbide papers, and 6 friction pairs were polished with a 0.25 μm diamond suspension after grinding. The friction pairs were tested for wear performance using a pin-on-disk tribometer with 10 N for 1.02 × 106 wear cycles in artificial saliva. Wear analysis of the pin and disk was performed with a 3D profilometer. The microstructure and worn surface morphology were examined with scanning electron microscopy. One-way analysis of variance and Tukey's post-hoc pairwise comparison were used to analyze the wear data. RESULTS The two group LD friction pairs presented strong time-dependent wear performance. The polished group (GP) exhibited a high wear rate and extensive surface wear during 0-1 × 105 cycles (running-in wear stage). The wear rate, height loss and surface roughness were obviously lower than those of grinded group (GG) in running-in wear stage. However, these wear parameters were similar during the steady wear stage. The worn surface topographies of the pin and disk in GP were smoother at the same cycle before the GG entering the steady wear stage. CONCLUSION Running-in, which means the initial stage of wear process, is a critical period to determine the final wear loss and surface degradation, when compare the wear behavior of lithium disilicate ceramic with different initial surface states. Ceramic layer with smooth contact area leads to low wear rate and short running-in wear stage.
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Sliding contact wear and subsurface damage of CAD/CAM materials against zirconia. Dent Mater 2020; 36:387-401. [PMID: 32007314 DOI: 10.1016/j.dental.2020.01.015] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2019] [Revised: 12/11/2019] [Accepted: 01/14/2020] [Indexed: 11/24/2022]
Abstract
OBJECTIVE Most previous work conducted on the wear behavior of dental materials has focused on wear rates and surface damage. There is, however, scarce information regarding the subsurface damage arising from sliding contact fatigue. The aim of this study was to elucidate the wear mechanisms and the subsurface damage generated during sliding contact fatigue in 5 contemporary CAD/CAM materials against a zirconia indenter. METHODS Forty discs (Ø12mm, 1.55mm thick) were cut out of IPS e.max CAD (e.CAD), Suprinity PC (SUP), Enamic (ENA), Vitablocs Mark II (VMII) and Lava Ultimate (LU) blocks and mirror polished. After cementation onto a dentin-like composite, off-axis mouth-motion cycling was conducted with a spherical zirconia indenter (r=3.18mm) in water (200N load, 2Hz frequency) for 5 different cycling periods (102, 103, 104, 105, 106 cycles, n=8). Analysis of the wear scars was conducted using light-microscopy, scanning-electron-microscopy and optical profilometry. Subsurface damage was assessed using sagittal and transverse sections of the samples. RESULTS Fatigue wear mechanisms predominated in glassy materials (e.CAD, SUP, VMII), accompanied by extensive subsurface damage, whereas abrasive wear mechanisms were responsible for the large wear craters in the resin composite (LU) with an absolute absence of subsurface fracture. A combination of both mechanisms was observed in the polymer-infiltrated reinforced-glass (ENA), displaying large wear craters and severe subsurface damage. SIGNIFICANCE Well-controlled laboratory simulation can identify wear and subsurface damage susceptibility of various classes of restorative materials. Both wear and subsurface fracture are determining factors for the long-term success of restorations.
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Stawarczyk B, Dinse L, Eichberger M, Jungbauer R, Liebermann A. Flexural strength, fracture toughness, three-body wear, and Martens parameters of pressable lithium-X-silicate ceramics. Dent Mater 2020; 36:420-430. [PMID: 32007315 DOI: 10.1016/j.dental.2020.01.009] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2019] [Revised: 11/26/2019] [Accepted: 01/14/2020] [Indexed: 11/24/2022]
Abstract
OBJECTIVES To test and compare five pressable lithium-X-silicate-ceramics on their mechanical and wear properties. METHODS Specimens were pressed and prepared from: i. Amber Press (AP), ii. Celtra Press (CP), iii. Initial LiSi Press (IL), iv. Livento Press (LP), and v. IPS e.max Press (IE). Four-point flexural strength (FS), SEVNB fracture toughness (KIC), three-body wear (3BW), Martens hardness (HM) and indentation modulus (EIT) were measured. For CP, FS and HM were measured with and without additional Power Firing. Each subgroup contained 15 specimens. Data were analyzed using Kolmogorov-Smirnov, one-way ANOVA followed by Scheffé test, Kruskal-Wallis-H-, Mann-Whitney-U-, and Spearman-Rho-test (p < 0.05). The Weibull modulus was calculated using the maximum likelihood estimation method. RESULTS AP and CP presented higher FS than IL. LP presented the highest Weibull modulus. CP showed lower KIC values than AP, and AP was not significant compared to LP and IE. The most 3BW material loss was observed for CP. CP revealed higher HM values than the remaining ceramics. IL presented lower EIT compared to AP and CP. The following correlations were observed between the test parameters: 3BW with FS (r = 0.279, p = 0.015), with HM (r = -0.378, p = 0.001), and with EIT (r = -0.344, p = 0.004); EIT with FS (r = 0.203, p = 0.028); and HM with FT (r = -0.223, p = 0.027) and EIT (r = 0.884, p < 0.001). No correlations were observed between FS and KIC (r = 0.046; p = 0.346). SIGNIFICANCE AP followed by LP showed the highest and IL followed by CP the lowest properties tested. Power Firing of CP improved the flexural strength. Ceramics with high flexural strength and Martens parameters showed lower wear. Materials with high Martens hardness presented lower fracture toughness values and ones with high indentation modulus showed high flexural strength.
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Affiliation(s)
- Bogna Stawarczyk
- Department of Prosthetic Dentistry, University Hospital, LMU Munich, 80336 Munich, Germany.
| | - Lina Dinse
- Department of Prosthetic Dentistry, University Hospital, LMU Munich, 80336 Munich, Germany
| | - Marlis Eichberger
- Department of Prosthetic Dentistry, University Hospital, LMU Munich, 80336 Munich, Germany
| | - Rebecca Jungbauer
- Department of Prosthetic Dentistry, University Hospital, LMU Munich, 80336 Munich, Germany
| | - Anja Liebermann
- Department of Prosthetic Dentistry, University Hospital, LMU Munich, 80336 Munich, Germany
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Schestatsky R, Zucuni CP, Dapieve KS, Burgo TAL, Spazzin AO, Bacchi A, Valandro LF, Pereira GKR. Microstructure, topography, surface roughness, fractal dimension, internal and marginal adaptation of pressed and milled lithium-disilicate monolithic restorations. J Prosthodont Res 2020; 64:12-19. [DOI: 10.1016/j.jpor.2019.05.004] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2019] [Revised: 05/16/2019] [Accepted: 05/20/2019] [Indexed: 11/28/2022]
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Gali S, K R. Zirconia toughened mica glass ceramics for dental restorations: Wear, thermal, optical and cytocompatibility properties. Dent Mater 2019; 35:1706-1717. [PMID: 31575490 PMCID: PMC7615828 DOI: 10.1016/j.dental.2019.08.112] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2019] [Revised: 07/18/2019] [Accepted: 08/31/2019] [Indexed: 11/18/2022]
Abstract
BACKGROUND In an effort to design novel zirconia reinforced mica glass ceramics for dental restorations, clinically relevant properties such as wear, coefficient of thermal expansion, optical transmittance, and cytocompatibility with human gingival fibroblast cell lines were investigated in the present study. MATERIALS & METHODS Microstructure analysis of two body wear of heat treated mica glass ceramic ceramics (47.2 SiO2-16.7 Al2O3-9.5 K2O-14.5 MgO-8.5 B2O3-6.3F wt.%) reinforced with 20wt.% YSZ, were evaluated against a steatite antagonist in a chewing simulator following Willytec Munich method. In addition, Coefficient of thermal expansion (CTE), total transmittance, scattering coefficient and cytocompatibility on human gingival fibroblast cell lines were performed and compared to the commercially available dental ceramic systems. RESULTS The experimental mica glass ceramic demonstrate micro-ploughing, pull out and debris formation along the cutting surface, indicating abrasive wear mechanism. Thermal expansion of mica glass ceramic composite was recorded as 5×10-6/°C, which is lower than the thermal expansion of commercially available core and veneering ceramics. Further, significant differences of transmittance and scattering coefficient of mica glass ceramics with 20wt.% YSZ with commercial dental ceramics was found and extensive fibroblast cell spreading with filopodial extension, cell-to-cell bridges and proliferation with human gingival fibroblast cell lines. CONCLUSION With acceptable cytocompatibility with human gingival fibroblast cells and better wear properties with respect to commercial IPS emax Press, the mica glass ceramic composites (47.2 SiO2-16.7Al2O3-9.5 K2O-14.5 MgO-8.5 B2O3-6.3F wt.%) with 20wt.% YSZ have the potential for dental restorative applications as machinable veneering ceramics.
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Affiliation(s)
- Sivaranjani Gali
- Dept. of Prosthodontics, Faculty of Dental Sciences, Ramaiah University of Applied Sciences 'MSRIT POST', New BEL Road, Bangalore, 560054, Karnataka, India.
| | - RaviKumar K
- Laboratory for Biomaterials, Material Research Centre, Indian Institute of Science, Bangalore, Karnataka, India.
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Alves LMM, Contreras LPC, Campos TMB, Bottino MA, Valandro LF, Melo RMD. In vitro wear of a zirconium-reinforced lithium silicate ceramic against different restorative materials. J Mech Behav Biomed Mater 2019; 100:103403. [DOI: 10.1016/j.jmbbm.2019.103403] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2019] [Revised: 08/13/2019] [Accepted: 08/19/2019] [Indexed: 11/26/2022]
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High-translucent yttria-stabilized zirconia ceramics are wear-resistant and antagonist-friendly. Dent Mater 2019; 35:1776-1790. [PMID: 31727445 DOI: 10.1016/j.dental.2019.10.009] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2019] [Revised: 10/04/2019] [Accepted: 10/14/2019] [Indexed: 12/13/2022]
Abstract
OBJECTIVES To evaluate two-body wear of three zirconia ceramics stabilized with 3, 4 and 5mol% yttria and to compare their wear behavior with that of a lithium-disilicate glass-ceramic. METHODS Sixteen rectangular-shaped specimens made from three grades of zirconia ceramics and a lithium-disilicate glass-ceramic were polished and dynamically loaded in a chewing simulator (2kg vertical load, 2.1Hz) under water at 90°C for 1.2×106 cycles (about 7 days) in the ball-on-plate mode against steatite antagonists. Surface roughness was measured before and after wear testing. Wear tracks were scanned with a non-contact 3D profilometer and super-impositions were used to determine wear loss of the antagonists. Wear surfaces were imaged by SEM. XRD and micro-Raman spectroscopy were used to characterize phase transformation and stress status in the worn and unworn areas of the zirconia ceramics. RESULTS Independent of fracture toughness, strength and aging-susceptibility, the three zirconia ceramics showed a similar and limited amount of wear (∼10μm in depth) and were more wear-resistant than the lithium-disilicate glass-ceramic (∼880μm in depth). Abrasive wear without obvious cracks was observed for all investigated zirconias, whereas the glass-ceramic with a lower fatigue threshold and high susceptibility to surface dissolution exhibited significant abrasion, fatigue and corrosion wear. All three zirconia ceramics yielded a lower antagonist wear than the glass-ceramic and no significant differences were found between the zirconia ceramics. SIGNIFICANCE In the context of this study, high-translucent zirconia ceramics stabilized with a higher yttria content, recently introduced in the dental field, were as wear-resistant and antagonist-friendly as conventional high-strength zirconia and suitable for monolithic restorations.
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Zarone F, Di Mauro MI, Ausiello P, Ruggiero G, Sorrentino R. Current status on lithium disilicate and zirconia: a narrative review. BMC Oral Health 2019; 19:134. [PMID: 31272441 PMCID: PMC6610968 DOI: 10.1186/s12903-019-0838-x] [Citation(s) in RCA: 160] [Impact Index Per Article: 32.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2019] [Accepted: 06/27/2019] [Indexed: 01/28/2023] Open
Abstract
Background The introduction of the new generation of particle-filled and high strength ceramics, hybrid composites and technopolymers in the last decade has offered an extensive palette of dental materials broadening the clinical indications in fixed prosthodontics, in the light of minimally invasive dentistry dictates. Moreover, last years have seen a dramatic increase in the patients’ demand for non-metallic materials, sometimes induced by metal-phobia or alleged allergies. Therefore, the attention of scientific research has been progressively focusing on such materials, particularly on lithium disilicate and zirconia, in order to shed light on properties, indications and limitations of the new protagonists of the prosthetic scene. Methods This article is aimed at providing a narrative review regarding the state-of-the-art in the field of these popular ceramic materials, as to their physical-chemical, mechanical and optical properties, as well as to the proper dental applications, by means of scientific literature analysis and with reference to the authors’ clinical experience. Results A huge amount of data, sometimes conflicting, is available today. Both in vitro and in vivo studies pointed out the outstanding peculiarities of lithium disilicate and zirconia: unparalleled optical and esthetic properties, together with high biocompatibility, high mechanical resistance, reduced thickness and favorable wear behavior have been increasingly orientating the clinicians’ choice toward such ceramics. Conclusions The noticeable properties and versatility make lithium disilicate and zirconia materials of choice for modern prosthetic dentistry, requiring high esthetic and mechanical performances combined with a minimal invasive approach, so that the utilization of such metal-free ceramics has become more and more widespread over time.
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Affiliation(s)
- Fernando Zarone
- Department of Neurosciences, Reproductive and Odontostomatological Sciences, University "Federico II" of Naples, Viale Pansini, 5 -, 80131, Naples, Italy
| | - Maria Irene Di Mauro
- Department of Neurosciences, Reproductive and Odontostomatological Sciences, University "Federico II" of Naples, Viale Pansini, 5 -, 80131, Naples, Italy.
| | - Pietro Ausiello
- Department of Neurosciences, Reproductive and Odontostomatological Sciences, University "Federico II" of Naples, Viale Pansini, 5 -, 80131, Naples, Italy
| | - Gennaro Ruggiero
- Department of Neurosciences, Reproductive and Odontostomatological Sciences, University "Federico II" of Naples, Viale Pansini, 5 -, 80131, Naples, Italy
| | - Roberto Sorrentino
- Department of Neurosciences, Reproductive and Odontostomatological Sciences, University "Federico II" of Naples, Viale Pansini, 5 -, 80131, Naples, Italy
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Hallmann L, Ulmer P, Gerngross MD, Jetter J, Mintrone M, Lehmann F, Kern M. Properties of hot-pressed lithium silicate glass-ceramics. Dent Mater 2019; 35:713-729. [DOI: 10.1016/j.dental.2019.02.027] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2018] [Accepted: 02/13/2019] [Indexed: 11/27/2022]
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Schestatsky R, Zucuni CP, Venturini AB, de Lima Burgo TA, Bacchi A, Valandro LF, Rocha Pereira GK. CAD-CAM milled versus pressed lithium-disilicate monolithic crowns adhesively cemented after distinct surface treatments: Fatigue performance and ceramic surface characteristics. J Mech Behav Biomed Mater 2019; 94:144-154. [PMID: 30897502 DOI: 10.1016/j.jmbbm.2019.03.005] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2019] [Revised: 03/07/2019] [Accepted: 03/08/2019] [Indexed: 11/24/2022]
Abstract
To evaluate the fatigue failure load (FFL), number of cycles for failure (CFF) and survival probabilities of lithium-disilicate (LD) monolithic crowns manufactured by two processing techniques (pressing vs. CAD/CAM) adhesively cemented to a dentin-analogue material, considering two surface treatments (conventional vs. simplified). Surface characteristics (topography, roughness and fractal dimensions) were also assessed. Forty (40) monolithic crowns were manufactured considering two specific processing techniques for each ceramic system: LDCAD - CAD/CAM lithium-disilicate (IPS e.max CAD, Ivoclar Vivadent); LDPRESS - pressed lithium-disilicate (IPS e.max Press, Ivoclar Vivadent). The crowns were adhesively cemented (Multilink Automix System, Ivoclar Vivadent) onto dentin analogue preparations considering two distinct protocols of surface treatments (conventional - hydrofluoric acid etching + silane application [HF+Sil] or simplified - etching with one-step primer (Monobond Etch&Prime, Ivoclar Vivadent) [EP]). The cemented assembly was stored in distilled water at 37 °C for 3 days and fatigue tests were run (step-stress approach: load ranging from 400 to 2000 N, step-size of 100 N, 15,000 cycles/step, 20 Hz). Fractography, surface topography, roughness, and fractal dimension analyses were performed. LDPRESS[EP] group depicted higher FFL, CFF and survival probabilities in comparison to LDCAD groups, regardless of the conditioning method. A tendency of higher Weibull modulus (mechanical reliability) was observed when using [EP] for both LDPRESS and LDCAD. SEM and AFM analysis showed very distinct initial surface patterns for the distinct processing techniques considered (LDCAD with higher fractal dimension and lower roughness than LDPRESS), and both surface treatments distinctly affected these surface characteristics. All failures were radial cracks originating at the ceramic-cement interface. Pressed lithium-disilicate monolithic crowns showed better fatigue performance in comparison to CAD/CAM milled crowns, especially when they were treated with self-etching ceramic primer. The surface treatment with self-etching primer led to similar fatigue performance when compared to hydrofluoric acid plus silane application for the same processing technique, but it tended to provide higher mechanical reliability.
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Affiliation(s)
- Ricardo Schestatsky
- MSciD Graduate Program, School of Dentistry, Meridional Faculty - IMED, Passo Fundo, Rio Grande do Sul State, Brazil.
| | - Camila Pauleski Zucuni
- MSciD and PhD Post-Graduate Program in Oral Science (Prosthodontics Units), Federal University of Santa Maria (UFSM), Santa Maria, Rio Grande do Sul State, Brazil.
| | - Andressa Borin Venturini
- MSciD and PhD Post-Graduate Program in Oral Science (Prosthodontics Units), Federal University of Santa Maria (UFSM), Santa Maria, Rio Grande do Sul State, Brazil.
| | | | - Atais Bacchi
- MSciD Graduate Program, School of Dentistry, Meridional Faculty - IMED, Passo Fundo, Rio Grande do Sul State, Brazil.
| | - Luiz Felipe Valandro
- MSciD and PhD Post-Graduate Program in Oral Science (Prosthodontics Units), Federal University of Santa Maria (UFSM), Santa Maria, Rio Grande do Sul State, Brazil.
| | - Gabriel Kalil Rocha Pereira
- MSciD Graduate Program, School of Dentistry, Meridional Faculty - IMED, Passo Fundo, Rio Grande do Sul State, Brazil.
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Microstructural development during heat treatment of a commercially available dental-grade lithium disilicate glass-ceramic. Dent Mater 2019; 35:697-708. [PMID: 30827800 DOI: 10.1016/j.dental.2019.02.011] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2018] [Revised: 01/21/2019] [Accepted: 02/07/2019] [Indexed: 11/21/2022]
Abstract
OBJECTIVE To elucidate the microstructural evolution of a commercial dental-grade lithium disilicate glass-ceramic using a wide battery of in-situ and ex-situ characterization techniques. METHODS In-situ X-ray thermo-diffractometry experiments were conducted on a commercially available dental-grade lithium disilicate glass-ceramic under both non-isothermal and isothermal heat treatments in air. These analyses were complemented by experiments of ex-situ X-ray diffractometry, field-emission scanning electron microscopy, energy-dispersive X-ray spectroscopy, differential scanning calorimetry, and field-emission scanning electron thermo-microscopy. RESULTS It was found that the non-fired blue block consists of ∼40 vol % crystals embedded in a glass matrix. The crystals are mainly lithium metasilicate (Li2SiO3) along with small amounts of lithium orthophosphate (Li3PO4) and lithium disilicate (Li2Si2O5). Upon heating, the glassy matrix in the as-received block first crystallizes partially as SiO2 (i.e., cristobalite) at ∼660 °C. Then, the SiO2 crystals react with the original Li2SiO3 crystals at ∼735 °C, forming the desired Li2Si2O5 crystals by a solid-state reaction in equimolar concentration (SiO2 + Li2SiO3 → Li2Si2O5). Precipitation of added colourant Ce ions in the form of CeO2 appears at ∼775 °C. These events result in a glass-ceramic material with the aesthetic quality and mechanical integrity required for dental restorations. It also has a microstructure consisting essentially of elongated Li2Si2O5 grains in a glassy matrix plus small cubic CeO2 grains at the outermost part of the surface. SIGNIFICANCE It was found that by judiciously controlling the heat treatment parameters, it is possible to tailor the microstructure of the resulting glass-ceramics and thus optimizing their performance and lifespan as dental restorations.
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Kruzic JJ, Arsecularatne JA, Tanaka CB, Hoffman MJ, Cesar PF. Recent advances in understanding the fatigue and wear behavior of dental composites and ceramics. J Mech Behav Biomed Mater 2018; 88:504-533. [PMID: 30223214 DOI: 10.1016/j.jmbbm.2018.08.008] [Citation(s) in RCA: 75] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2018] [Revised: 08/06/2018] [Accepted: 08/08/2018] [Indexed: 12/30/2022]
Abstract
Dental composite and ceramic restorative materials are designed to closely mimic the aesthetics and function of natural tooth tissue, and their longevity in the oral environment depends to a large degree on their fatigue and wear properties. The purpose of this review is to highlight some recent advances in our understanding of fatigue and wear mechanisms, and how they contribute to restoration failures in the complex oral environment. Overall, fatigue and wear processes are found to be closely related, with wear of dental ceramic occlusal surfaces providing initiation sites for fatigue failures, and subsurface fatigue crack propagation driving key wear mechanisms for composites, ceramics, and enamel. Furthermore, both fatigue and wear of composite restorations may be important in enabling secondary caries formation, which is the leading cause of composite restoration failures. Overall, developing a mechanistic description of fatigue, wear, and secondary caries formation, along with understanding the interconnectivity of all three processes, are together seen as essential keys to successfully using in vitro studies to predict in vivo outcomes and develop improved dental restorative materials.
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Affiliation(s)
- Jamie J Kruzic
- School of Mechanical and Manufacturing Engineering, UNSW Sydney, Sydney, NSW 2052, Australia.
| | | | - Carina B Tanaka
- School of Mechanical and Manufacturing Engineering, UNSW Sydney, Sydney, NSW 2052, Australia
| | - Mark J Hoffman
- School of Mechanical and Manufacturing Engineering, UNSW Sydney, Sydney, NSW 2052, Australia; School of Materials Science and Engineering, UNSW Sydney, Sydney, NSW 2052, Australia
| | - Paulo F Cesar
- Department of Biomaterials and Oral Biology, School of Dentistry, University of São Paulo, São Paulo, Brazil
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Fracture-free surfaces of CAD/CAM lithium metasilicate glass-ceramic using micro-slurry jet erosion. J Mech Behav Biomed Mater 2018; 80:59-67. [PMID: 29414476 DOI: 10.1016/j.jmbbm.2018.01.022] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2017] [Revised: 01/18/2018] [Accepted: 01/22/2018] [Indexed: 11/20/2022]
Abstract
This paper reports the use of micro-slurry jet erosion (MSJE) on CAD/CAM lithium mesilicate glass ceramic (LMGC) that is capable of achieving the fracture-free surface quality. A computer-controlled MSJE process using a low-pressure and low-concentration alumina slurry was applied to diamond-ground LMGC surfaces with surface and subsurface damage. The MSJE processed and diamond-ground LMGC surfaces were examined using scanning electron microscopy (SEM) to examine surface morphology, fractures, and residual defects. 3D confocal laser microscopy (CLM) was used to quantitatively characterize all machined surface textures as a function of processing conditions. Our results show that surface and subsurface damage induced in diamond-ground surfaces were significantly diminished after 50-cycle MSJE processing. Fracture-free surfaces were obtained after 100 MSJE cycles. Our measured parameters of the 3D surface topography included the average surface roughness, maximum peak-valley height, highest peak height, lowest valley height, and kurtosis and absolute skewness of height distributions. All these parameters were significantly reduced with the increase of MSJE cycles. This work implies that MSJE promises to be an effective manufacturing technique for the generation of fracture-free LMGC surfaces which are crucial for high-quality monolithic restorations made from the material.
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ÖZDEMİR H, ÖZDOĞAN A. The effect of heat treatments applied to superstructure porcelain on the mechanical properties and microstructure of lithium disilicate glass ceramics. Dent Mater J 2018; 37:24-32. [DOI: 10.4012/dmj.2016-365] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Affiliation(s)
- Hatice ÖZDEMİR
- Faculty of Dentistry, Prosthodontics Department, Atatürk University
| | - Alper ÖZDOĞAN
- Faculty of Dentistry, Prosthodontics Department, Atatürk University
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22
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Handa K, Murakami N, Yamazaki T, Takahashi H, Wakabayashi N. The ball-on-disk cyclic wear of CAD/CAM machinable dental composite and ceramic materials. J Oral Sci 2017; 59:589-596. [PMID: 29151459 DOI: 10.2334/josnusd.16-0833] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022]
Abstract
The purpose of this study was to investigate the wear volume and the principal strain of machinable dental composite and ceramics in simulated mastication. A ball-on-disk wear test was performed for 3,000 cycles in water, using nine ball/disk combinations of three commercial CAD/CAM materials: feldspathic, lithium disilicate glass ceramics, and a highly loaded composite material (n = 7 for each combination). The wear volume was optically measured using a digital scanner and analyzed for statistical differences based on the materials (α = 0.05). We used non-linear finite element analysis to calculate the principal strain. The wear volume of the ball was significantly larger than that of the disk when hardness and fracture toughness of the former was lower than that of the latter and vice versa (P < 0.05). The lithium disilicate glass ceramic constantly showed lower wear volume than the opposing antagonist. Except for the same material pairs of feldspathic and composite, the ball or disk specimen that showed a larger wear in the occluding pair coincided with the one with higher maximum strain. It was not possible to predict the magnitude of wear, whereas the result suggested a strong association between the maximum strain and wear volume of the ceramic surface.
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Affiliation(s)
- Kazuyuki Handa
- Removable Partial Prosthodontics, Department of Masticatory Function Rehabilitation, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University
| | - Natsuko Murakami
- Removable Partial Prosthodontics, Department of Masticatory Function Rehabilitation, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University
| | - Toshiki Yamazaki
- Removable Partial Prosthodontics, Department of Masticatory Function Rehabilitation, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University
| | - Hidekazu Takahashi
- Oral Biomaterials Development Engineering, Course for Oral Health Engineering, School of Oral Health Care Sciences, Tokyo Medical and Dental University
| | - Noriyuki Wakabayashi
- Removable Partial Prosthodontics, Department of Masticatory Function Rehabilitation, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University
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Alao AR, Stoll R, Song XF, Abbott JR, Zhang Y, Abduo J, Yin L. Fracture, roughness and phase transformation in CAD/CAM milling and subsequent surface treatments of lithium metasilicate/disilicate glass-ceramics. J Mech Behav Biomed Mater 2017. [PMID: 28645068 DOI: 10.1016/j.jmbbm.2017.06.015] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
This paper studied surface fracture, roughness and morphology, phase transformations, and material removal mechanisms of lithium metasilicate/disilicate glass ceramics (LMGC/LDGC) in CAD/CAM-milling and subsequent surface treatments. LMGC (IPS e.max CAD) blocks were milled using a chairside dental CAD/CAM milling unit and then treated in sintering, polishing and glazing processes. X-ray diffraction was performed on all processed surfaces. Scanning electron microscopy (SEM) was applied to analyse surface fracture and morphology. Surface roughness was quantitatively characterized by the arithmetic average surface roughness Ra and the maximum roughness Rz using desktop SEM-assisted morphology analytical software. The CAD/CAM milling induced extensive brittle cracks and crystal pulverization on LMGC surfaces, which indicate that the dominant removal mechanism was the fracture mode. Polishing and sintering of the milled LMGC lowered the surface roughness (ANOVA, p < 0.05), respectively, while sintering also fully transformed the weak LMGC to the strong LDGC. However, polishing and glazing of LDGC did not significantly improve the roughness (ANOVA, p > 0.05). In comparison of all applied fabrication process routes, it is found that CAD/CAM milling followed by polishing and sintering produced the smoothest surface with Ra = 0.12 ± 0.08µm and Rz = 0.89 ± 0.26µm. Thus, it is proposed as the optimized process route for LMGC/LDGC in dental restorations. This route enables to manufacture LMGC/LDGC restorations with cost effectiveness, time efficiency, and improved surface quality for better occlusal functions and reduced bacterial plaque accumulation.
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Affiliation(s)
- Abdur-Rasheed Alao
- Mechanical Engineering, College of Science and Engineering, James Cook University, Townsville QLD 4811, Australia
| | - Richard Stoll
- Restorative Dentistry, College of Medicine and Dentistry, James Cook University, Cairns QLD 4870, Australia
| | - Xiao-Fei Song
- Key Laboratory of Advanced Ceramics and Machining Technology of Ministry of Education, School of Mechanical Engineering, Tianjin University, Tianjin 300072, China
| | - John R Abbott
- JCU Dental, James Cook University, Cairns QLD 4870, Australia
| | - Yu Zhang
- Department of Biomaterials and Biomimetics, New York University College of Dentistry, New York, NY 10010, USA
| | - Jaafar Abduo
- Melbourne Dental School, Melbourne University, 720 Swanston Street, Melbourne, Victoria 3010, Australia
| | - Ling Yin
- Mechanical Engineering, College of Science and Engineering, James Cook University, Townsville QLD 4811, Australia.
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Guo J, Li D, Wang H, Yang Y, Wang L, Guan D, Qiu Y, He L, Zhang S. Effect of contact stress on the cycle-dependent wear behavior of ceramic restoration. J Mech Behav Biomed Mater 2017; 68:16-25. [PMID: 28135638 DOI: 10.1016/j.jmbbm.2017.01.027] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2016] [Revised: 01/14/2017] [Accepted: 01/20/2017] [Indexed: 11/18/2022]
Abstract
AIM Ceramic restoration experiences the non-linear wear process during the chewing simulation, which contains running-in, steady and severe wear stages. However since various levels of contact stress may be applied on the occlusal surface during chewing, the cycle-dependent wear behaviors of ceramic crowns may differ. The aim of this study was to investigate the effect of contact stress on the development of wear behavior, as tested in a chewing simulator. MATERIALS AND METHODS Thirty-six anatomical metal-ceramic crowns using Ceramco III as the veneering porcelain were randomly assigned to two groups based on the contact stress applied in the wear testing. Stainless steel balls served as antagonists. The specimens were dynamically loaded in a chewing simulator up to 2.4×106 loading cycles, with additional thermal cycling between 5 and 55℃. For each group, several checkpoints were employed to measure the substance loss of the crowns' occlusal surfaces and to evaluate the microstructure of the worn areas. RESULTS After 2.4×106 cycles, the ceramic restorations with lower contact stress demonstrated a long steady wear stage following the running-in, but without the severe wear stage. And a slowly microstructural degradation was observed that the subsurface defect could not be seen until final. With higher contact stress, however, the ceramic restorations experienced a faster transition from running-in to severe wear stage that the steady wear stage nearly disappeared. And an early formation of subsurface defects and the deterioration of microstructure were observed. CONCLUSIONS Contact stress is a key factor affecting the wear development of ceramic restoration. The higher contact stress promotes the veneering porcelain to evolve into severe wear stage. In contrast, lower contact stress is prone to keep the veneering porcelain operating in steady wear stage, which delays the arrival of severe wear region.
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Affiliation(s)
- Jiawen Guo
- Department of Stomatology, Lanzhou General Hospital, Lanzhou Command of PLA, Lanzhou, Gansu, China
| | - Ding Li
- State Key Laboratory for Mechanical Behavior of Materials, Xi'an Jiaotong University, Xi'an, China
| | - Haijing Wang
- Oral Biosciences, Faculty of Dentistry, The University of Hong Kong, Prince Philip Dental Hospital, 34 Hospital Road, Sai Ying Pun, Hong Kong
| | - Yanwei Yang
- Department of Stomatology, Lanzhou General Hospital, Lanzhou Command of PLA, Lanzhou, Gansu, China
| | - Liying Wang
- Department of Stomatology, Lanzhou General Hospital, Lanzhou Command of PLA, Lanzhou, Gansu, China
| | - Delin Guan
- Department of Stomatology, Lanzhou General Hospital, Lanzhou Command of PLA, Lanzhou, Gansu, China
| | - Yinong Qiu
- Department of Stomatology, Lanzhou General Hospital, Lanzhou Command of PLA, Lanzhou, Gansu, China
| | - Lin He
- State Key Laboratory for Mechanical Behavior of Materials, Xi'an Jiaotong University, Xi'an, China.
| | - Shaofeng Zhang
- State Key Laboratory of Military Stomatology & National Clinical Research Center for Oral Diseases & Shaanxi Key Laboratory of Oral Diseases, Department of Prosthodontics, School of Stomatology, Fourth Military Medical University, Xi'an, China.
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Theodoro GT, Fiorin L, Moris ICM, Rodrigues RCS, Ribeiro RF, Faria ACL. Wear resistance and compression strength of ceramics tested in fluoride environments. J Mech Behav Biomed Mater 2017; 65:609-615. [DOI: 10.1016/j.jmbbm.2016.09.039] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2016] [Accepted: 09/28/2016] [Indexed: 10/20/2022]
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Does 8-methacryloxyoctyl trimethoxy silane (8-MOTS) improve initial bond strength on lithium disilicate glass ceramic? Dent Mater 2016; 33:e95-e100. [PMID: 27890356 DOI: 10.1016/j.dental.2016.11.004] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2016] [Revised: 09/16/2016] [Accepted: 11/01/2016] [Indexed: 11/21/2022]
Abstract
OBJECTIVES Dental ceramic surfaces are modified with silane coupling agents, such as γ-methacryloxypropyl trimethoxy silane (γ-MPTS), to improve bond strength. For bonding between lithium disilicate glass ceramic and resin cement, the objective was to investigate if 8-methacryloxyoctyl trimethoxy silane (8-MOTS) could yield a similar performance as the widely used γ-MPTS. METHODS One hundred and ten lithium disilicate glass ceramic specimens were randomly divided into 11 groups (n=10) according to pretreatment regime. All specimens were pretreated with a different solution composed of one or a combination of these agents: 10 or 20wt% silane coupling agent of γ-MPTS or 8-MOTS, followed by a hydrolysis solution of acetic acid or 10-methacryloyloxydecyl dihydrogen phosphate (10-MDP). Each pretreated surface was luted to a stainless steel rod of 3.6mm diameter and 2.0mm height with resin cement. Shear bond strength between ceramic and cement was measured after 24-h storage in 37°C distilled water. RESULTS 8-MOTS produced the same bonding performance as γ-MPTS. Both silane coupling agents significantly increased the bond strength of resin cement, depending on their concentration. When activated by 10-MDP hydrolysis solution, 20wt% concentration produced the highest values (γ-MPTS: 24.9±5.1MPa; 8-MOTS: 24.6±7.4MPa). Hydrolysis with acetic acid produced lower bond strengths than with 10-MDP. SIGNIFICANCE Silane coupling pretreatment with 8-MOTS increased the initial bond strength between lithium disilicate glass ceramic and resin cement, rendering the same bonding effect as the conventional γ-MPTS.
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"Digitally Oriented Materials": Focus on Lithium Disilicate Ceramics. Int J Dent 2016; 2016:9840594. [PMID: 27635140 PMCID: PMC5007340 DOI: 10.1155/2016/9840594] [Citation(s) in RCA: 66] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2016] [Accepted: 07/25/2016] [Indexed: 11/17/2022] Open
Abstract
The present paper was aimed at reporting the state of the art about lithium disilicate ceramics. The physical, mechanical, and optical properties of this material were reviewed as well as the manufacturing processes, the results of in vitro and in vivo investigations related to survival and success rates over time, and hints for the clinical indications in the light of the latest literature data. Due to excellent optical properties, high mechanical resistance, restorative versatility, and different manufacturing techniques, lithium disilicate can be considered to date one of the most promising dental materials in Digital Dentistry.
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