Biomaterial Database

[Analysis of the unsuccessful cases of the porcelain-fused-to-metal-crowns and bridges]. 2005

Li-Yun Zhai, and Yu-Zhen Zhao, and Shao-Ping Wang, and Yue-Hua Yang

Dept. of Prosthodontics, Tianjin Oral Hospital, Tianjin 30041, China.

OBJECTIVE To discuss the unsuccessful reasons and the preventive methods of the unsuccessful clinic cases. METHODS The retrospective analysis was carried on the 80 prosthesis in 70 patients from 1994 to 2001 which were suffered with unsuccessful results after the restoration of the metal crowns and bridges. RESULTS There were 68 teeth which had collapsed or broken. 20 teeth had the post loosing or shedding. Root breaking, food impaction, unharmony colors of porcelain and the changing color of gingival were 3, 3, 6 and 2 teeth. CONCLUSIONS It is necessary to select suitable repairing materials and operate correctly for preventing the occurring of the unsuccessful results in the porcelain-fused-to-metal-crowns and bridges.

UI	MeSH Term	Description	Entries
D008670	Metals	Electropositive chemical elements characterized by ductility, malleability, luster, and conductance of heat and electricity. They can replace the hydrogen of an acid and form bases with hydroxyl radicals. (Grant & Hackh's Chemical Dictionary, 5th ed)	Metal
D008963	Molar	The most posterior teeth on either side of the jaw, totaling eight in the deciduous dentition (2 on each side, upper and lower), and usually 12 in the permanent dentition (three on each side, upper and lower). They are grinding teeth, having large crowns and broad chewing surfaces. (Jablonski, Dictionary of Dentistry, 1992, p821)	Molars
D003442	Crowns	A prosthetic restoration that reproduces the entire surface anatomy of the visible natural crown of a tooth. It may be partial (covering three or more surfaces of a tooth) or complete (covering all surfaces). It is made of gold or other metal, porcelain, or resin.	Dental Crowns,Crown, Dental,Crowns, Dental,Dental Crown,Crown
D003776	Dental Porcelain	A type of porcelain used in dental restorations, either jacket crowns or inlays, artificial teeth, or metal-ceramic crowns. It is essentially a mixture of particles of feldspar and quartz, the feldspar melting first and providing a glass matrix for the quartz. Dental porcelain is produced by mixing ceramic powder (a mixture of quartz, kaolin, pigments, opacifiers, a suitable flux, and other substances) with distilled water. (From Jablonski's Dictionary of Dentistry, 1992)	Porcelain,Porcelain, Dental,Dental Porcelains,Porcelains,Porcelains, Dental
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D012189	Retrospective Studies	Studies used to test etiologic hypotheses in which inferences about an exposure to putative causal factors are derived from data relating to characteristics of persons under study or to events or experiences in their past. The essential feature is that some of the persons under study have the disease or outcome of interest and their characteristics are compared with those of unaffected persons.	Retrospective Study,Studies, Retrospective,Study, Retrospective
D014092	Tooth Root	The part of a tooth from the neck to the apex, embedded in the alveolar process and covered with cementum. A root may be single or divided into several branches, usually identified by their relative position, e.g., lingual root or buccal root. Single-rooted teeth include mandibular first and second premolars and the maxillary second premolar teeth. The maxillary first premolar has two roots in most cases. Maxillary molars have three roots. (Jablonski, Dictionary of Dentistry, 1992, p690)	Root, Tooth,Roots, Tooth,Tooth Roots