This multicentre study analysed 12 alumina ceramic-on-ceramic components retrieved from squeaking total hip replacements after a mean of 23 months in situ (11 to 61). The rates and patterns of wear seen in these squeaking hips were compared with those seen in matched controls using retrieval data from 33 'silent' hip replacements with similar ceramic bearings. All 12 bearings showed evidence ch...

Although an all-ceramic restoration is increasingly in use in dentistry, a conventional metal ceramic restoration is still considered to be a gold standard. However, with increasing demand in esthetics and advances in ceramic technology, future of metal ceramic restoration has been less certain, necessitating additional qualities in terms of superior esthetics and easy fabrication. A ceramic-pr...

Pyroplastic deformation is a distortion of the ceramic shape during the sintering process. It occurs because the flow of the vitreous phase at high temperature and the applied stress due to the weight of the product during sintering process. The aim of this paper deals with describing a numerical-experimental method to evaluate the pyroplastic deformation, to predict the anisotropic shrinkage a...

Hydroxyapatite bio-ceramic powder was synthesized using waste eggshells as calcium source by a straight forward thermal method. The process is carried out at high temperature. Different calcium phosphate phases were obtained just by changing the thermal treatment. HAp is the only apatite present in the reaction products, along with minute fractions of other calcium compounds. The final product ...

in this research, synthesis and characterization of silver/alumina composite powders was investigated. this kind of metal/ceramic composite powders is used for fabrication of cutting tools inserts. the role of silver is toughening the final product. the powders were synthesized via co-precipitation method. the composition of the synthesized powders was ag/80% wt 〖al〗_2 o_3. silver nitrate, alum...

The aims of this study were to investigate the effects of two surface-conditioning methods on the shear bond strength (SBS) of metal brackets bonded to three different all-ceramic materials, and to evaluate the mode of failure after debonding. Twenty feldspathic, 20 fluoro-apatite, and 20 leucite-reinforced ceramic specimens were examined following two surface-conditioning methods: air-particle...

statement of problem: mechanical failure of ceramic materials is controlled by brittle fracture, mostly occurred in tension. in 3-unit all-ceramic fpds the connector area is considered to be at fracture risk because of tensile stress concentrations. purpose: the aim of this fe analysis was to evaluate the effect of taper on stress distribution in all-ceramic fpds. materials and methods: in this...

A simulated upper jaw, made from a rubber arch containing replaceable ceramic teeth and a renewable composite jawbone, offers promise in assessing the performance of custom made mouthguard designs. Impact tests, involving precise assessment of jaw and tooth fractures caused by projectiles of various energies and profiles, simulate conditions that approximate to common clinical observation. Such...

The last 25 years have witnessed the introduction of a bewildering number of ceramic systems to the dental profession. Most of these systems have been introduced with little or no clinical testing. Laboratory studies of physical and mechanical properties of ceramics provide little predictive information regarding likely clinical survival rates. Early adopters of many of these new systems learne...

Biodegradable elastomeric materials are gaining extensive attention in the field of soft tissue engineering. Poly (glycerol sebacate) (PGS) is a novel biocompatible elastomer in this scope. However this polymer has poor mechanical properties especially when the molar ratio of glycerol is higher than sebacic acid. Calcium Titanate (CaTiO3) is a biocompatible ceramic with some degr...