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Query: UMLS:C0432222 (SEM)
 47,337 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The structural events observed in enamel, cementum, and dentin during the caries process have been reviewed. In incipient enamel lesions, the prevailing concept of an almost intact surface layer has been seriously challenged by SEM and TEM observations demonstrating structural pathways (such as enlarged prism junctions or sheaths) from the enamel surface to the sub-surface lesion. The destruction in this latter location consisted of (1) enlarged prism junctions, (2) diffuse mineral destruction in the prism cores, and (3) destruction of the interprismatic substance. In root caries, the destruction of cementum started along junctions between calcified layers of extrinsic (Sharpey) and intrinsic collagen fibers as well as along incremental lines. Invasion of Gram-positive micro-organisms followed these enlarged junctions. Dentin caries was similar in coronal and root caries. It consisted of sclerosis of the lumens of the dentinal tubules, followed by an important gradient of demineralization of intertubular dentin and destruction of occluded tubular lumens and peritubular dentin. Bacterial penetration occurred initially in the dentinal tubules and was followed by bacterial invasion and destruction of the intertubular dentin. Various phenomena of crystalline remineralization were described in enamel and dentin. Whereas in enamel and dentin caries, an important gradient of demineralization was observed before bacterial invasion, a simultaneous destruction of the mineral and organic components seemed to occur in cementum.
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PMID:Structural events in the caries process in enamel, cementum, and dentin. 217 14

This study was planned to investigate the remineralization potential of the inner carious dentin layer preserved under adhesive resin restoration in comparison with that under cement filling. Dentin caries models were artificially produced in vivo with acid on the Class V cavity floors of 25 bilateral tooth pairs from 3 monkeys. Thirteen cavity pairs were filled with adhesive composite and twelve pairs with polycarboxylate cement, 120 days and immediately before sacrificing the monkeys. The sections through the floor dentin layer were examined by an optical microscope, Knoop hardness tester, EPMA and SEM. The findings obtained were as follows: 1. Two different dentin layers were recognized on the decalcified floor dentin. 2. The outer highly decalcified layer of about 100 microns thickness was not found to be remineralizable in vivo. 3. The inner partially decalcified layer of about 80 microns thickness was proved to be physiologically remineralizable even under adhesive resin restoration, having the possible irritation of acid-etching or resin monomers. 4. Increase in the Ca content in the inner decalcified layer under resin restoration observed after 120 days was more remarkable than that under cement.
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PMID:[Physiological remineralization of artificially decalcified monkey dentin under adhesive composite resin restoration]. 274 6