Biomaterial Database

Disturbed enamel mineralization in a rat incisor model. 1996

K Sato, and M Hattori, and T Aoba

Nippon Dental University, Department of Pathology, Tokyo, Japan.

Possession of full-thickness hard enamel appears to be one of the indispensable life-saving characteristics of rats. Previous studies by Suga and his colleagues and by others demonstrated that various types of malformation are evoked in continuously erupting rat incisors. In the current report, we directed our effort to oversee various types of enamel malformation caused experimentally in rat incisors. We surveyed the specimens collected by Suga and his colleagues, as well as specimens we obtained. From the results, it is conceivable that perturbation of the programmed sequential events during enamel development is a major factor in the establishment of enamel malformation. Animal studies with either 1-hydroxyethylidene-1,1-bisphosphonate (HEBP) or a multidentate phosphonic acid (EDTPO) confirmed that dentin mineralization provides a certain inductive effect on the secretion of enamel matrix and subsequent enamel crystallization. Our recent studies using anti-microtubular agents led to the conclusion that the acceleration of mineralization in outer enamel is a type of enamel malformation, most likely due to disruption of the cellular regulation of calcium transport under severe toxic regimens. In future work, experimental approaches combining measurements of kinetic factors with static observation of enamel lesions are required before we can gain a comprehensive understanding of the pathogenesis of disturbed enamel mineralization. The kinetic factors to be considered include the rates of tissue apposition and tooth eruption which determine the total volume of tooth substance formed, and the rate of mineral accretion. Furthermore, information as to the composition, crystallinity, solubility, and mechanical properties of enamel defects is needed before we can assess the susceptibility of teeth having those lesions to caries and other physico-chemical attacks in the oral environment.

UI	MeSH Term	Description	Entries
D007180	Incisor	Any of the eight frontal teeth (four maxillary and four mandibular) having a sharp incisal edge for cutting food and a single root, which occurs in man both as a deciduous and a permanent tooth. (Jablonski, Dictionary of Dentistry, 1992, p820)	Incisors
D002118	Calcium	A basic element found in nearly all tissues. It is a member of the alkaline earth family of metals with the atomic symbol Ca, atomic number 20, and atomic weight 40. Calcium is the most abundant mineral in the body and combines with phosphorus to form calcium phosphate in the bones and teeth. It is essential for the normal functioning of nerves and muscles and plays a role in blood coagulation (as factor IV) and in many enzymatic processes.	Coagulation Factor IV,Factor IV,Blood Coagulation Factor IV,Calcium-40,Calcium 40,Factor IV, Coagulation
D003743	Dental Enamel	A hard thin translucent layer of calcified substance which envelops and protects the dentin of the crown of the tooth. It is the hardest substance in the body and is almost entirely composed of calcium salts. Under the microscope, it is composed of thin rods (enamel prisms) held together by cementing substance, and surrounded by an enamel sheath. (From Jablonski, Dictionary of Dentistry, 1992, p286)	Enamel,Enamel Cuticle,Dental Enamels,Enamel, Dental,Enamels, Dental,Cuticle, Enamel,Cuticles, Enamel,Enamel Cuticles,Enamels
D003744	Dental Enamel Hypoplasia	An acquired or hereditary condition due to deficiency in the formation of tooth enamel (AMELOGENESIS). It is usually characterized by defective, thin, or malformed DENTAL ENAMEL. Risk factors for enamel hypoplasia include gene mutations, nutritional deficiencies, diseases, and environmental factors.	Enamel Hypoplasia,Enamel Agenesis,Enamel Hypoplasia, Dental,Hypoplasia, Dental Enamel,Hypoplastic Enamel,Agenesis, Enamel,Enamel Ageneses,Enamel Hypoplasias,Enamel, Hypoplastic,Hypoplasia, Enamel
D003810	Dentinogenesis	The formation of dentin. Dentin first appears in the layer between the ameloblasts and odontoblasts and becomes calcified immediately. Formation progresses from the tip of the papilla over its slope to form a calcified cap becoming thicker by the apposition of new layers pulpward. A layer of uncalcified dentin intervenes between the calcified tissue and the odontoblast and its processes. (From Jablonski, Dictionary of Dentistry, 1992)	Dentinogeneses
D005260	Female		Females
D000565	Ameloblasts	Cylindrical epithelial cells in the innermost layer of the ENAMEL ORGAN. Their functions include contribution to the development of the dentinoenamel junction by the deposition of a layer of the matrix, thus producing the foundation for the prisms (the structural units of the DENTAL ENAMEL), and production of the matrix for the enamel prisms and interprismatic substance. (From Jablonski's Dictionary of Dentistry, 1992)	Ameloblast
D000566	Amelogenesis	The elaboration of dental enamel by ameloblasts, beginning with its participation in the formation of the dentino-enamel junction to the production of the matrix for the enamel prisms and interprismatic substance. (Jablonski, Dictionary of Dentistry, 1992).	Amelogeneses
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D014074	Tooth Calcification	The process whereby calcium salts are deposited in the dental enamel. The process is normal in the development of bones and teeth. (Boucher's Clinical Dental Terminology, 4th ed, p43)	Calcification, Tooth,Teeth Calcification,Calcification, Teeth,Calcifications, Teeth,Calcifications, Tooth,Teeth Calcifications,Tooth Calcifications