Over the past forty years, the technological evolution of ceramics for dental applications has been remarkable, as new materials and processing techniques are steadily being introduced. The improvement in both strength and toughness has made it possible to expand the range of indications to long-span fixed partial prostheses, implant abutments and implants. The present review provides a state of the art of ceramics for dental applications.

https://www.mdpi.com/1996-1944/3/1/351/pdf

Ceramics for Dental Applications: A Review

Dental ceramics are presented within a simplifying framework allowing for facile understanding of their development, composition and indications. Engineering assessments of clinical function are dealt with and literature is reviewed on the clinical behaviour of all-ceramic systems. Practical aspects are presented regarding the choice and use of dental ceramics to maximize aesthetics and durability, emphasizing what we know and how we know it.

https://onlinelibrary.wiley.com/doi/epdf/10.1111/j.1834-7819.2010.01299.x

Ceramic materials in dentistry: historical evolution and current practice

Statement of problem The recent development of polymer-based computer-aided design and computer-aided manufactured (CAD/CAM) milling blocks and the limited availability of independent studies on these materials make it pertinent to evaluate their properties and identify potential strengths and limitations. Purpose The purpose of this in vitro study was to determine and compare mechanical properties (flexural strength, flexural modulus, modulus of resilience) and compare the margin edge quality of recently introduced polymer-based CAD/CAM materials with some of their commercially available composite resin and ceramic counterparts. Material and methods The materials studied were Lava Ultimate Restorative (LVU; 3M ESPE), Enamic (ENA; Vita Zahnfabrik), Cerasmart (CES; GC Dental Products), IPS Empress CAD (EMP; Ivoclar Vivadent AG), Vitablocs Mark II (VM2; Vita Zahnfabrik), and Paradigm MZ100 Block (MZ1; 3M ESPE). Polished 4×1×13.5 mm bars (n=25) were prepared from standard-sized milling blocks of each tested material. The bars were subjected to a 3-point flexural test on a 10-mm span with a crosshead speed of 0.5 mm/min. In addition, 42 conventional monolithic crowns (7 per material) were milled. Margin edge quality was observed by means of macrophotography and optical microscopy, providing a qualitative visual assessment and a measurement of existing roughness. The results were analyzed by ANOVA followed by the Tukey HSD test (α=.05). Results The mean flexural strength of the tested materials ranged from 105 ±9 MPa (VM2) to 219 ±20 MPa (CES). The mean flexural modulus ranged from 8 ±0.25 GPa (CES) to 32 ±1.9 GPa (EMP). The mean modulus of resilience ranged from 0.21 ±0.02 MPa (VM2) to 3.07 ±0.45 MPa (CES). The qualitative assessment of margin edge roughness revealed visible differences among the tested materials, with mean roughness measurements ranging from 60 ±16 μm (CES) to 190 ±15 μm (EMP). The material factor had a significant effect on the mean flexural strength ( P P P P Conclusions The new-generation polymer-based materials tested in this study exhibited significantly higher flexural strength and modulus of resilience, along with lower flexural modulus values compared with the tested ceramic or hybrid materials. Crowns milled from the new resin-based blocks seemed to exhibit visibly smoother margins compared with the ceramic materials studied.

Mechanical properties of resin-ceramic CAD/CAM restorative materials

Our goal is to give an overview of a selection of emerging ceramics and issues for dental or biomedical applications, with emphasis on specific challenges associated with full-contour zirconia ceramics, and a brief synopsis on new machinable glass-ceramics and ceramic-based interpenetrating phase composites. Selected fabrication techniques relevant to dental or biomedical applications such as microwave sintering, spark plasma sintering, and additive manufacturing are also reviewed. Where appropriate, the authors have added their opinions and guidance.

Emerging Ceramic-based Materials for Dentistry

Advances in digital impression technology and manufacturing processes have led to a dramatic paradigm shift in dentistry and to the widespread use of computer-aided design/computer-aided manufacturing (CAD/CAM) in the fabrication of indirect dental restorations. Research and development in materials suitable for CAD/CAM applications are currently the most active field in dental materials. Two classes of materials are used in the production of CAD/CAM restorations: glass-ceramics/ceramics and resin composites. While glass-ceramics/ceramics have overall superior mechanical and esthetic properties, resin-composite materials may offer significant advantages related to their machinability and intra-oral reparability. This review summarizes recent developments in resin-composite materials for CAD/CAM applications, focusing on both commercial and experimental materials.

Resin-composite Blocks for Dental CAD/CAM Applications

Mechanical properties of polymer-infiltrated-ceramic-network materials

http://www.osteocom.net/osteocom/modules/Friend/images/1-s20-s0109564111002260-main_43948.pdf

Thermal gradients and residual stresses in veneered Y-TZP frameworks

Objectives To determine the flexural strength and subsequent strength degradation of a range of dental CAD/CAM ceramic materials and novel PICN (Polymer-Infiltrated-Ceramic-Network) materials by means of pre-damaging with Vickers indentations at various loads. Methods The materials tested included (Mark II, PICN test material 1 and 2, In-Ceram Alumina, VM 9, In-Ceram YZ; Vita Zahnfabrik, Bad Saeckingen, Germany) and (IPS e.max CAD, Ivoclar Vivadent, Schaan, Liechtenstein). Bending bars were cut and lapped with 15 µm diamond suspension. Initial flexural strength (n=10) was determined in three-point-bending. To evaluate the damage tolerance, Vickers indentations were placed on the bending bars (n=35) with varying loads (1.96–98.07 N). The indented bending bars were subsequently loaded to fracture in three-point-bending. In addition, the fracture toughness was determined by the indentation strength (IS) and the SEVNB technique (n=5). Results With increasing indentation loads the fracture strength of all materials tested decreased. The material with the highest fracture resistance to indentation induced damage, was the PICN test material 1 with an indentation load-flexural strength curve slope of 0.21. In-Ceram YZ exhibited the highest damage susceptibility with a slope of 0.4. The fracture toughness varied with the measurement technique and material in the range of 0.82 (VM 9) to 4.94 (In-Ceram YZ) MPa√m for the SEVNB method and 0.96 (VM 9) to 4.97 (In-Ceram YZ) MPa√m for the IS method respectively. Significance This study aims to indicate the likely clinical behavior by evaluating the damage tolerance and R-curve behavior of dental ceramics by in-vitro strength degradation and fracture toughness measurements.

In-vitro strength degradation of dental ceramics and novel PICN material by sharp indentation.

http://www.osteocom.net/osteocom/modules/Friend/images/1-s20-s0109564109000086-main_04748.pdf

Norbert Thiel

Papers

Mechanical properties of polymer-infiltrated-ceramic-network materials

Thermal gradients and residual stresses in veneered Y-TZP frameworks

In-vitro strength degradation of dental ceramics and novel PICN material by sharp indentation.

SEM observations of porcelain Y-TZP interface

Damage tolerance of indirect restorative materials (including PICN) after simulated bur adjustments.