Biomaterial Database

Ceramic inlay movement during polymerization of resin luting cements. 1995

J A Sorensen, and E C Munksgaard

Department of Dental Materials, School of Dentistry, Faculty of Health Sciences, University of Copenhagen, Denmark.

In cavities with no support for inlays, polymerization contraction of the resin cement may move the ceramic inlay axially. The purpose of this study was to determine the velocity and extent of such movement. Cylindrical ceramic inlays were placed in dentin cavities filled with one of four commercially available resin composite cements. An initial standardized 200-microns-thick cement film was created. The movement of the ceramic inlay during polymerization of one of the resin cements was measured by a dial gauge. The velocity of the inlay movement decreased exponentially with time and with a velocity constant of 0.09 min-1. The majority of the movement occurred within the first 12 min after photopolymerization and probably continued for several days, reaching an estimated value of 5.8 microns. After 1-2 d of water storage, 1-2-microns contraction gaps at the cavity floors were observed microscopically for every cement used. It is concluded that in cavities without support for the inlay, about 2/3 of the resin cement contraction results in movement of the inlay and about 1/3 results in formation of gaps at the cavity floors.

UI	MeSH Term	Description	Entries
D007284	Inlays	Restorations of metal, porcelain, or plastic made to fit a cavity preparation, then cemented into the tooth. Onlays are restorations which fit into cavity preparations and overlay the occlusal surface of a tooth or teeth. Onlays are retained by frictional or mechanical factors.	Dental Inlays,Dental Onlays,Onlays,Dental Inlay,Dental Onlay,Inlay, Dental,Inlays, Dental,Onlay, Dental,Onlays, Dental,Inlay,Onlay
D008027	Light	That portion of the electromagnetic spectrum in the visible, ultraviolet, and infrared range.	Light, Visible,Photoradiation,Radiation, Visible,Visible Radiation,Photoradiations,Radiations, Visible,Visible Light,Visible Radiations
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
D009068	Movement	The act, process, or result of passing from one place or position to another. It differs from LOCOMOTION in that locomotion is restricted to the passing of the whole body from one place to another, while movement encompasses both locomotion but also a change of the position of the whole body or any of its parts. Movement may be used with reference to humans, vertebrate and invertebrate animals, and microorganisms. Differentiate also from MOTOR ACTIVITY, movement associated with behavior.	Movements
D003188	Composite Resins	Synthetic resins, containing an inert filler, that are widely used in dentistry.	Composite Resin,Resin, Composite,Resins, Composite
D003737	Dental Cavity Preparation	An operation in which carious material is removed from teeth and biomechanically correct forms are established in the teeth to receive and retain restorations. A constant requirement is provision for prevention of failure of the restoration through recurrence of decay or inadequate resistance to applied stresses. (Boucher's Clinical Dental Terminology, 4th ed, p239-40)	Cavity Preparation, Dental,Cavity Preparations, Dental,Dental Cavity Preparations,Preparation, Dental Cavity,Preparations, Dental Cavity
D003738	Dental Cements	Substances used to bond COMPOSITE RESINS to DENTAL ENAMEL and DENTIN. These bonding or luting agents are used in restorative dentistry, ROOT CANAL THERAPY; PROSTHODONTICS; and ORTHODONTICS.	Dental Adhesives,Luting Agents,Orthodontic Adhesives,Cement, Dental,Cements, Dental,Dental Cement,Adhesive, Dental,Adhesive, Orthodontic,Adhesives, Dental,Adhesives, Orthodontic,Dental Adhesive,Luting Agent,Orthodontic Adhesive
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
D003804	Dentin	The hard portion of the tooth surrounding the pulp, covered by enamel on the crown and cementum on the root, which is harder and denser than bone but softer than enamel, and is thus readily abraded when left unprotected. (From Jablonski, Dictionary of Dentistry, 1992)	Dentine,Dentines,Dentins
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man