All-ceramic Computer-aided Design and Computer-aided Manufacturing Restorations: Evolution of Structures and Criteria for Clinical Application

Abstract

Background: At a time when esthetics is becoming increasingly important in society, the metal-ceramic system, although clinically reliable in the long term, no longer grants satisfaction in terms of mimicry and biocompatibility. Over the last two decades, the growth of computer-aided design and computer-aided manufacturing (CAD/CAM) systems has promoted the development of new all-ceramic materials. However, the abundance and diversity of the suggested materials involved in fixed prosthetic rehabilitation place the practitioner in a situation of conflict regarding the choice of selecting the type of restoration appropriate to the clinical situation presented to him/her. Aim: The aim of this article is to classify the different types of milled ceramics according to their microstructure, to review the clinical indications of each, and to indicate whether they should be cemented or bonded. Results: The diverse sorts of milled ceramics using the CAD/CAM procedures are classified into four categories according to their chemical nature. Therefore, the large constitutional and structural variety of the all-ceramic materials will define the esthetic and mechanical properties of each group. Conclusion:The all-ceramic CAD/CAM restorations are witnessing a well-deserved rise, knowing that none of those milled ceramics has a universal clinical application. Clinical significance: Given the abundance and diversity of the new machined ceramics materials, it is necessary to familiarize with their properties as well as with their mode of assembling to the dental structures to ensure the success and durability of the restoration.

Evaluation of Marginal/Internal Fit and Fracture Load of Monolithic Zirconia and Zirconia Lithium Silicate (ZLS) CAD/CAM Crown Systems

“…Currently, CAD/CAM techniques have found widespread application for all types of prostheses—fixed, partial, and completely removable, with different types of ceramic and polymer-based materials [ 10 , 15 , 16 , 86 ]. Future studies comparing the fit accuracy and fracture resistance of the latest monolithic translucent Zi (partially and fully stabilized zirconia), fully crystallized ZLS, and nano-ceramic materials with the monolithic Y-TZP, LDS, and ZLS pre-crystallized glass ceramic materials are required to test the efficacy of the new materials for different types of indirect fixed restorations.…”

“…Although zirconia (Zi) has favorable mechanical properties for a variety of applications in dentistry, the white color and poor translucency of the material precluded the use for full contoured restorations in the past [ 5 , 6 , 7 , 8 , 9 ]. Recently, translucent tooth-colored Zi, which enables fabrication of restorations without the veneering porcelain, has been developed [ 10 , 11 , 12 ]. Lithium disilicates have also been in wide use for making complete coverage crowns in dentistry [ 13 , 14 ], and the material can be either pressed or milled by CAD/CAM.…”

“…Some specific restoration-based factors are the ceramic material composition and properties, internal fit, processing variations, crown dimensions/geometry, and finishing/glazing effect. The substrate-related reasons include modulus of elasticity and preparation design [ 10 , 11 , 12 , 16 ]. Although many papers have examined the fracture load of different types of ceramic restorations, data are scarce on the in-vitro fatigue performance and fracture load of single posterior crowns made with the new monolithic translucent Zi and ZLS ceramic materials.…”

Effect of Different Scaling Methods on the Surface Topography of Different CAD/CAM Ceramic Compositions

“…The use of ceramic materials in dental restorations has increased due to their excellent combination of esthetic, biological, and mechanical properties, such as wear resistance and stiffness, making them an important material for rehabilitation in the mouth [10]. Lithium disilicate and leucite-reinforced CAD/CAM ceramics have shown favorable results when used in the fabrication of esthetic restorations of moderate strength in the anterior region extending Materials 2023, 16, 2974 2 of 12 to the maxillary premolars and the short span 3-unit fixed partial dentures (FPDs) [7][8][9]11]. These ceramics were developed in different shades and multiple translucencies in order to match the esthetic appearance and brightness of anterior teeth [7,12].…”