Dentine primary

Beighton D and Lynch E (1995) Comparison of selected microflora of plaque and underlying carious dentine associated with primary root caries lesions. Caries Res 29, 154-158. 

Once an agent is topically applied in the oral cavity, the free drug can act at the primary site (i.e., bacteria in the plaque), or it can be partitioned to compartments where the drug binds nonspecifically. These drug reservoirs include the enamel, dentin, and/or cementum of the tooth, the oral mucosa, the organic and inorganic components of plaque, and salivary proteins. 

The biocompatible CBPC development has occurred only in the last few years, and the recent trend has been to evaluate them as biocompatible ceramics. After all, biological systems form bone and dentine at room temperature, and it is natural to expect that biocompatible ceramics should also be formed at ambient temperature, preferably in a biological environment when placed in a body as a paste. CBPCs allow such placement. We have discussed such calcium phosphate-based cements in Chapter 13. Calcium-based CBPCs, especially those constituting hydroxyapatite (HAP), are a natural choice. HAP is a primary mineral in bone [3], and hence calcium phosphate cements can mimic natural bone. Some of these ceramics with tailored composition and microstructure are already in use, yet there is ample room for improvement. This Chapter focuses on the most recent biocompatible CBPCs and their testing in a biological environment. To understand biocompatible material and its biological environment, it is first necessary to understand the structure of bone and how it is formed. 

Di nosdc for walrus ivory is that it is the only ivory to contain primary and secondary dentine. The former displays very finely packed, concentric lines and makes up the bulk of the tusk. The latter has a bubbly appearance like that of tapioca or rice pudding (Figs 3.3 and 3.16). It fills the centre of the tusk all the way through from the tip to a small pulp cavity in the part of the tusk attached to the jawbone. This secondary dentine looks more fragile than the primary dentine, but it has the same hardness, and the material can be carved and polished with Htde regard to the difGerent textures (Fig. 3.3). 

The primary mechanisms postulated for these dentifrices are that they occlude dentinal tubules, preventing stimuli from the oral cavity from irritating the dental nerve via these tubules. Also, those containing potassium may depolarize nerve fibers resulting in decreased impulse conduction and an associated decrease in pain. 

Lakomaa. E.-L (1980). Use of NAA in the determination of elements in human cerebrospinal fluid, in Trace Element Analytical Chemistry in Medicine and Biology. Braatter, P. and Schramel, P., Ed., Walter de Gruyter Co., New York, p.97 Lakomaa, E.-L and Rytomaa, I. (1977). Mineral composition of enamel and dentin of primary and permanent teeth in Finland, Scand. J. Dent. Res. 85,89-95 Langmyhr, F.J., Lind, T. and Jonsen, J. (1975). Atomic absorption spectrometric determination of manganese, silver and zinc in dental material by atomization directly from the solid state. Anal. Chim. Acta 80, 297-301... 

L. Angkur, N. Nijhof, M.V. Swain, N.M. Kilpatrick, Influence of hydration and mechanical characterization of carious primary dentine using an ultra-micro indentation system (UMIS), Eur. J. Oral Sci. 112 (2004) 231-236. 

A. Cetinguc, S. Olmez, N. Vural, HEMA diffusion from dentine bonding agents in young and old primary molars in vitro. Dent. Mater. 23 (2007) 302-307. 

C. Ribeiro, L. Baratieri, J. Pedigao, N. Baratieii, A. Ritter, A clinical, radiographic and scanning electron microscopic evaluation of adhesive restorations on carious dentin in primary teeth, Quintessence Int. 30 (1999) 591-599. 

Lakomaa, E-L. and Rytomaa, I. (1977) Mineral composition of enamel and dentin of primary and permanent teeth in Finland. Scand. J. Dent. Res., 85, 89-95. 

One of the primary aspects allowing for such rapid transition has been an improved understanding of the complexity of the mineral-matrix interactions occurring in mineralized tissues, particularly in dentin and bone. Early work has identified that in mineralized tissues, collagen fibrils are reinforced with mineral crystallites that are positioned both intrafibrillarly (inside the fibrils) and... 

Some of the papers referenced do this for rubber, nylon and tooth dentins. Peterlin, Zhurkov et al. and Becht have also made quantitative measures of bond rupture. In answer to your second question, our experimental evidence (J. Polym. Sci. A-1, 7, 2125 (1969) indicates only a small fraction of the total work of fracture can be attributed to primary bond rupture. The remainder may be attributed to secondary bond rupture, plastic and viscoelastic deformation somewhat analogous to work of plastic deformation at the tip of a crack in metals. 

It is likely that differences in lead levels in different types of teeth found in whole-tooth analysis, are in part due to the relative proportions of enamel, primary and secondary dentine in different teeth, but this does not explain why there should be a difference in samples of circumpulpal dentine from incisors in different jaws. 

The deposition of lead in primary dentine, the major component of dentine... 

The importance of consensus in terminology was highlighted by a misunderstanding of the analytical procedures employed, because of a differential use of the labels, primary, secondary and circumpulpal dentine, by different research groups. This indicated one area where improvements in inter-study communication could be made with ease. Exchange of personnel between study groups to observe analytical procedures, or a video-recording to demonstrate the process, would resolve such differences. The latter procedure would also provide a record which could be kept for reference purposes. 

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