The aim of the study was to find the optimum combination of materials and thicknesses to provide a tough, damage resistant multi-layer system with numerical methods to restore the damaged teeth. Extended Finite Element Method (XFEM) was used to assess the critical loads for the onset of damage modes such as radial cracks and plastic deformation in dental prostheses, which consist of a brittle o...

A preceding study of contact damage in a bilayer system consisting of a porcelain coating on a stiff Pd-alloy substrate is here expanded to investigate the role of substrate modulus and hardness. Bilayers are made by fusing the same dental porcelain onto Co-, Pd-, and Au-alloy metal bases. Indentations are made on the porcelain surfaces using spheres of radii 2.38 and 3.98 mm. Critical loads to...

STATEMENT OF PROBLEM Bonded porcelain veneers are widely used esthetic restorations. Although high success and survival rates have been reported, failures occur. Fracture is the most common failure mode. Fractures range from incomplete cracks to the catastrophic. Minimally invasive or thin partial veneers have gained popularity. PURPOSE The aim of this study was to measure the influences of p...

The widespread use of porcelain in restorative dentistry is generally due to its esthetic appearance even though it is brittle. The transverse strength, or modulus rupture, averages around 108 MPa (16,000 psi) for aluminous porcelain and 88 MPa (13,000 psi) for feldspathic porcelain. The tensile strength, as determined by diametral compression, is approximately 29 MPa (4,200 psi) for opaque fel...

STATEMENT OF PROBLEM Bonded porcelain veneers are widely used esthetic restorations. High success and survival rates have been reported, but failures do occur. Fractures are the commonest failure mode. Minimally invasive or thin veneers have gained popularity. Increased enamel and porcelain thickness improve the strength of veneers bonded to enamel, but less is known about dentin or mixed subst...

A mechanically retentive structure and meticulous surface cleanliness are critical factors in providing fracture resistance and clinical success of metal ceramic restorations. This investigation compared the porcelain/metal interfaces of deliberate compressive fractures of ceramic crowns between conventional preparation and application of the Radio Frequency Glow Discharge Treatment (RFGDT) bef...

Introduction: Marginal fit is a key factor for long term clinical success through any dental restorations. Poor marginal adaptation causes cement dissolution. This can lead to dental caries, gingival irritation, periodontal diseases, and finally treatment failure. The aim of this study was measurement and comparison of marginal gap quantities in metal ceramic and all ceramic dental restorations...

The mechanisms contributing to failure of full dental ceramic crowns under occlusal loads were studied using a unique optical approach. Model specimens comprising triple-layered crowns (veneer, core and substrate) were developed with both flat and curved occlusal surfaces and then subjected to simulated quasi-static occlusal loading using a spherical indenter. Deformation within the specimens d...

Porcelain laminate veneers are used routinely in cosmetic dentistry. The public usually refers to this mode of treatment simply as “veneers.” Their popularity has increased because of television makeover programs, commercials, and magazine advertisements. Porcelain laminate veneers have so increased in their attractiveness that the general public is demanding this type of instant makeover. Furt...

Light-cured flowable composites were introduced to the dental profession in 1995 with Revolution. The original manufacturer (E & D Dental Products) recommended that it could be used for Class III, IV, and V restorations, porcelain veneer cementation, porcelain and marginal defect repairs, sealants, and core buildups. Amazingly, one of the most popular contemporary uses of flowable composites, n...