Recent Advances in Ceramics for Dentistry

For the last ten years, the application of high-technology processes to dental ceramics allowed for the development of new materials such as heat-pressed, injection-molded, and slip-cast ceramics and glass-ceramics. The purpose of the present paper is to review advances in new materials and processes available for making all-ceramic dental restorations. Concepts on the structure and strengthening mechanisms of dental ceramics are provided. Major developments in materials for all-ceramic restorations are addressed. These advances include improved processing techniques and greater mechanical properties. An overview of the processing techniques available for all-ceramic materials is given, including sintering, casting, machining, slip-casting, and heat-pressing. The most recent ceramic materials are reviewed with respect to their principal crystalline phases, including leucite, alumina, forsterite, zirconia, mica, hydroxyapatite, lithium disilicate, sanidine, and spinel. Finally, a summary of flexural strength data available for all-ceramic materials is included.

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Optimized sintering and mechanical properties of Y-TZP ceramics for dental restorations by adding lithium disilicate glass ceramics

Journal of Advanced Ceramics ◽

10.1007/s40145-021-0507-9 ◽

2021 ◽

Author(s):

Ke Li ◽

Jiancun Rao ◽

Congqin Ning

Keyword(s):

Sol Gel ◽

Tetragonal Zirconia ◽

Glass Ceramics ◽

Lithium Disilicate ◽

The Novel ◽

Dental Ceramics ◽

Abnormal Growth ◽

Dental Restorations ◽

All Ceramic ◽

Ceramic Restorations

AbstractThe novel dental ceramics can be fabricated at lower temperatures when sol-gel derived lithium disilicate glass ceramics (LDGC) was used as an additive for yttria stabilized tetragonal zirconia polycrystalline (Y-TZP) ceramics. The effect of LDGC on the sintering, mechanical, and translucent properties of Y-TZP ceramics was investigated in the present study. The results showed that the LDGC additive effectively improved the densification of Y-TZP at 1100 °C, which was much lower than the sintering temperature for pure Y-TZP. When sintered at 1100 °C, the Y-TZP with 1 wt% LDGC reached a relative density of 95.45%, and prossessed a flexural strength of 482.4 MPa and a fracture toughness of 5.94 MPa·m1/2. Moreover, its translucency was also improved. While, the addition of LDGC could result in an escape of yttrium atoms from the grain lattice of zirconia, which induced the tetragonal-monoclinic transformation of zirconia and abnormal growth of monoclinic grains. The escaped yttrium atoms diffused into the intergranular glass phase. The results indicated that the novel Y-TZP-LDGC ceramics has a great potential to be used for all-ceramic restorations.

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Demystifying Modern Dental Ceramics

Primary Dental Journal ◽

10.1308/205016819827601527 ◽

2019 ◽

Vol 8 (3) ◽

pp. 28-33

Author(s):

Kasim Butt ◽

Naren Thanabalan ◽

Khawer Ayub ◽

George Bourne

Keyword(s):

Survival Data ◽

Survival Rates ◽

Ceramic Materials ◽

Clinical Indication ◽

Dental Ceramics ◽

High Quality ◽

Dental Restorations ◽

Modes Of Failure ◽

Ceramic Restorations

With increasing patient expectation for aesthetic dental restorations, there has been a drive towards developing ceramic materials to meet this expectation. Multiple ceramic systems have been introduced over the past four decades with considerable advances in material properties. Survival rates of all-ceramic crowns differ by type of ceramic used, fabrication method and clinical indication. Zirconia and lithium disilicate are the most commonly used contemporary ceramic materials in dentistry. Survival data for these types of restorations appears to be promising; however, there is a lack of high-quality long-term clinical data on the success of these restorations. In the absence of robust longitudinal clinical research, laboratory studies have provided some useful information on the performance of ceramic restorations. Further high quality long-term clinical studies are needed to inform us of modes of failure of these restorations and the range of clinical circumstances in which each type of ceramic restoration may be used.

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Low Temperature Degradation of Y-TZP Ceramic for Dental Applications

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.873.241 ◽

2013 ◽

Vol 873 ◽

pp. 241-249

Author(s):

Zhi Kai Wu ◽

Ning Li ◽

Wan Qian Zhao ◽

Jia Zhen Yan

Keyword(s):

Low Temperature ◽

Substantial Reduction ◽

Tetragonal Zirconia ◽

Ceramic Materials ◽

Dental Ceramics ◽

All Ceramic ◽

Long Time ◽

Core Thickness ◽

Dental Applications

Yttria-stabilized tetragonal zirconia polycrystalline (Y-TZP) ceramic has been recently introduced into prosthetic dentistry for the fabrication of crowns and fixed partial dentures (FPDs). The mechanical properties of Y-TZP are the highest ever reported for the all-ceramic materials. This is favorable for the fabrication of multi-unit posterior bridges and the substantial reduction in core thickness. However, Y-TZP ceramic is susceptible to low temperature degradation (LTD), which is detrimental to the long-time survival and aesthetics of zirconia restorations in vivo. This review summarizes the characterization, mechanisms, and influencing factors of the LTD in dental Y-TZP ceramic. In addition, the recent trend of exploring high aging resistant zirconia-based dental ceramics is discussed.

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Transformation toughening of glass ceramics

Journal of Materials Research ◽

10.1557/jmr.1987.0801 ◽

1987 ◽

Vol 2 (6) ◽

pp. 801-804 ◽

Cited By ~ 19

Author(s):

D. R. Clarke ◽

B. Schwartz

Keyword(s):

Glass Ceramic ◽

Tetragonal Zirconia ◽

Glass Ceramics ◽

Ceramic Materials ◽

Nucleation Event ◽

Transformation Toughening ◽

Glass Ceramic Materials ◽

Polycrystalline Ceramic ◽

Cordierite Glass ◽

Processing Techniques

The utilization of transformation toughening has hitherto been restricted to increasing the fracture resistance of polycrystalline ceramic materials. Although a number of investigators have attempted to extend the concept to toughening glasses and glass ceramics with tetragonal zirconia, no successful reports have been published. It is argued that the approaches employed are inevitably limited primarily because they do not take into account the necessity of nucleating the tetragonal-to-monoclinic transformation away from the crack tip itself. By concentrating on the nucleation event and using standard ceramic processing techniques, it has been demonstated that transformation toughening can be used to increase the toughness of glass-ceramic materials, and this approach is illustrated by increasing the fracture toughness of a cordierite glass ceramic.

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Zirconia Dental Implant Materials

Materials Science Forum ◽

10.4028/www.scientific.net/msf.907.99 ◽

2017 ◽

Vol 907 ◽

pp. 99-103

Author(s):

Sergiu Ciprian Focșăneanu ◽

Petrică Vizureanu ◽

Andrei Victor Sandu ◽

Mădălina Simona Bălţatu

Keyword(s):

Mechanical Properties ◽

Mechanical Strength ◽

Dental Implants ◽

Clinical Studies ◽

Glass Ceramics ◽

Ceramic Materials ◽

Medical Applications ◽

Dental Restorations ◽

Esthetic Dentistry ◽

Titanium Dental Implants

Ceramic materials are used for the fabrication of dental restorations respectively esthetic dentistry. The main ceramic materials are glass ceramics, spinel, alumina and zirconia. Zirconia was introduced into dentistry domain in the 1990s used like frameworks, implants, dowels, abutments and orthodontic brackets. Recently, zirconia materials are getting much attention for dental implants because of its toothlike color, mechanical properties, good corrosion and biocompatibility. This article presents an review of zirconia dental implants osseointegration and mechanical strength compared with other dental implants. Clinical studies published indicate that zirconia dental implants have the potential to become alternative of titanium dental implants used in medical applications.

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Esthetic Rehabilitation of Anterior Teeth with Copy-Milled Restorations: A Report of Two Cases

Case Reports in Dentistry ◽

10.1155/2017/2841398 ◽

2017 ◽

Vol 2017 ◽

pp. 1-5 ◽

Cited By ~ 3

Author(s):

Sapna Rani ◽

Jyoti Devi ◽

Chandan Jain ◽

Parul Mutneja ◽

Mahesh Verma

Keyword(s):

Clinical Success ◽

Ceramic Materials ◽

Digital Revolution ◽

Anterior Teeth ◽

All Ceramic ◽

Computer Aided ◽

Recent Developments ◽

Cad Cam ◽

Copy Milling ◽

Ceramic Restorations

Digitalization has become part and parcel of contemporary prosthodontics with the probability of most of the procedures being based on the digital techniques in the near future. This digital revolution started in the latter half of the 20th century by converting analog objects/signals into digital bits and bytes. Recent developments in all-ceramic materials and systems of computer-aided designing and computer-aided manufacturing (CAD/CAM), copy milling, and so forth offer excellent esthetics and superb biocompatibility. Copy milling system for ceramics enables milling of the zirconia cores of all-ceramic restorations precisely and also if this system is properly used the procedure for fabricating all-ceramic restorations can be substantially simplified. This case report presents fabrication of all-ceramic Maryland Bridge and post-core with a copy milling system for esthetics and preservation of integrity of tooth. For both of the patients, the use of biologic, all-ceramic, copy-milled restorations resulted in clinical success and recovered function and esthetics.

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The influence of multiple firing on thermal contraction of ceramic materials used for the fabrication of layered all-ceramic dental restorations

Dental Materials ◽

10.1016/j.dental.2004.08.006 ◽

2005 ◽

Vol 21 (6) ◽

pp. 557-564 ◽

Cited By ~ 29

Author(s):

G ISGRO ◽

C KLEVERLAAN ◽

H WANG ◽

A FEILZER

Keyword(s):

Ceramic Materials ◽

Thermal Contraction ◽

Dental Restorations ◽

All Ceramic ◽

Materials Used

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Machinability of Zirconia Toughened Mica Glass Ceramics for Dental Restorations

Brazilian Dental Science ◽

10.14295/bds.2021.v24i1.2114 ◽

2020 ◽

Vol 24 (1) ◽

Author(s):

Sivaranjani Gali ◽

Suresh Chiru

Keyword(s):

Surface Roughness ◽

Tool Wear ◽

Feed Rate ◽

Cutting Forces ◽

Glass Ceramics ◽

Spindle Speed ◽

Depth Of Cut ◽

Dental Ceramics ◽

Edge Chipping ◽

Dental Restorations

Objective: For a dental material to be machinable for CAD/CAM technology, it must offer convenient machining, under a given set of cutting conditions. Quantitative evaluation of machinability has been assessed in literature through various parameters such as tool wear, penetration rates, surface roughness, cutting force and power. A machinable ceramic will typically demonstrate a higher tool penetration rate with signs of reduced diamond tool wear and edge chipping. The purpose of this in vitro study was to evaluate the feasibility of machining an experimental ceramic, 20 wt.% zirconia reinforced mica glass ceramics (G20Z) for indirect dental restorations and compare the tool penetration rates of G20Z to commercially available dental ceramics, Presintered Zirconia (PSZ) and IPS emax CAD. Material and Methods: Precursors of base glass (SiO2 -Al2O3 -K2O -MgO-B2O3 -F) were melted at 15000C for 2 h in a platinum crucible and quenched in deionised water. The glass frit was ball milled with 20 wt. % YSZ (G20Z) and subject to two stage heat treatment in a muffle furnace. Specimens of G20Z (12 X 2 mm) were evaluated for their feasibility of machining under varying spindle speed, depth of cut, and feed rates. Influence of depth of cut, spindle speed and feed rate (vc=8000-16000 rpm, d=0.4-0.8 mm, f=0.1- 0.3 mm/tooth) on cutting forces, material response, surface roughness and tool wear were investigated. Tool penetration rates, tool wear and margin chipping were also evaluated and compared with Pre-sintered Zirconia (PSZ) and e.max CAD in a custom dental milling surveyor at 30,000 rpm with a load of 0.98 N under water lubrication for 6 min. Tool penetration rates were calculated as the ratio of length of cut and milling time with a measuring microscope and scanning electron microscope was used for tool wear and edge chipping. ANOVA and Tukey Kramer tests were used for statistically comparing the means of each group. Results: Spindle speed and feed rate play a significant role in influencing surface roughness, thrust force, cutting forces and tool wear. Penetration rates of G20Z (0.32 ±0.12 mm/min) was significantly greater than PSZ (0.26 ±0.06 mm/min) and IPS e.max CAD (0.21 ±0.05 mm/min). SEM observations reveal tool abrasion and edge chipping regardless of the ceramic type. Conclusion: High spindle speeds delivers low cutting forces with an average surface roughness of 1.61 µm, with abrasive wear of the tool insert and brittle fracture of zirconia mica glass ceramic composites. G20Z with its machinable nature demonstrates greater tool penetration rates than PSZ and IPS e.max CAD. Tool wear and edge chipping is seen in all the investigated ceramics. Keywords Machinability, Dental Ceramics, Mica Glass-Ceramics, Dental Zirconia, Tool penetration rates.

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Study of Machinable Dental Glass Ceramics

Materials Science Forum ◽

10.4028/www.scientific.net/msf.620-622.575 ◽

2009 ◽

Vol 620-622 ◽

pp. 575-578 ◽

Cited By ~ 1

Author(s):

Xin Pei Ma ◽

Guang Xin Li ◽

Zhi Hao Jin ◽

Ji Hua Chen ◽

Mao Ju Yang ◽

...

Keyword(s):

Glass Ceramics ◽

Orthogonal Experimental Design ◽

Computer Assisted ◽

X Ray Diffraction ◽

X Ray ◽

Dental Restorations ◽

Computer Assisted Design ◽

All Ceramic ◽

Cad Cam ◽

Good Biocompatibility

Glass-ceramics are especially useful for the dental restorations because of their good biocompatibility, chemical stability, aesthetic, mechanical strength and wear resistance. The aim of this work was to obtain one mica glass-ceramic, which can be easily used for rapid machining into all-ceramic tooth with computer assisted design/computer assisted manufacture (CAD/CAM) devices. In the study, on the base of low melting machinable fluorosilicic mica glass ceramics, the effects of CeO2 and Fe2O3 in SiO2-B2O3-K2O-Na2O-Li2O-Al2O3-MgO-F system on color were studied. By orthogonal experimental design, the effects of crystallized parameters on the color, three point flexural strength and machinability of the glass ceramics were obtained, and the samples were analyzed by differential thermal analysis(DTA), X-ray diffraction (XRD) and scanning electron microscopy(SEM), respectively. Experimental results showed that the glass-ceramics with color close to the tooth can be obtained by adjusting the percentage of CeO2 and Fe2O3, and the glass-ceramics crystallized at 680°C for 2h have excellent mechanical properties and machinability.

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