Analytical and ultrastructural studies of pellicle on primary teeth.

The pellicle on permanent enamel has been thoroughly studied. The aims of this study were to compare the chemical composition, rate of formation, and ultrastructural appearance of pellicle formed on deciduous enamel in children with those on permanent teeth. This was done by amino acid analyses, Auger analyses, and transmission electron microscopy.

Caries development in fluoridated and non-fluoridated deciduous and permanent enamel in situ examined by microradiography and confocal laser scanning microscopy.

The aim of the study was to compare initial caries development in fluoridated and non-fluoridated deciduous and permanent enamel in situ. Enamel slabs were mounted in removable appliances and worn for 4 wks. Significantly larger lesions developed in deciduous than in permanent enamel when no topical fluorides were used.

Fluoride release and uptake in vitro from a composite resin and two orthodontic adhesives.

The aim of this study was to investigate the fluoride release and uptake characteristics of a composite resin (Tetric) and two orthodontic adhesives (VP 862 and Saga Bond), with a type-II glass ionomer cement (Ketac Fil) as a control. Test specimens in 2 ml deionized water released fluoride over a period of 33 days. Ketac Fil released 54 and 15 times more fluoride than Tetric after 24 h and 1 month, respectively, whereas the two adhesives released amounts between these values.

Rate of pellicle formation in vivo.

The acquired enamel pellicle is thought to be the result of a selective adsorption of salivary proteins and to be involved in the protection of the enamel surfaces. The chemical composition of the 2-h acquired enamel pellicle is fairly well established. However, the rate of formation and the amino acid composition of the initially formed enamel pellicle have been little investigated.

A comparison of the anticaries effect on the primary dentition of two dentifrices containing 250 ppm and 1450 ppm fluoride.

The purpose of the study was to compare the anticaries effects of two dentifrices containing sodium fluoride with fluoride concentrations of 250 ppm and 1450 ppm on the primary dentition of kindergarten children. A total of 319 children participated in the study (155 in the low-fluoride and 164 in the high-fluoride group) and brushed their teeth daily under supervision in their kindergartens. The children were examined by one dentist trained according to the procedures of O'Mullane et al.

Amino acid composition of acquired enamel pellicle collected in vivo after 2 hours and after 24 hours.

The adsorption of salivary proteins to dental enamel during pellicle formation has been shown to be a specific process and dependent on the chemical composition of the surfaces. Most studies on the amino acid composition of the acquired enamel pellicle have, however, been performed on the "2-h-pellicle" under controlled experimental conditions. This may have eliminated some natural factors involved in pellicle formation.

Chemical analysis and scanning electron microscopy of acquired pellicle formed in vivo on stannous fluoride treated enamel.

Stannous fluoride (SnF2) has been shown to be an effective caries preventive agent. After topical treatment of enamel surfaces, two reaction products have been demonstrated to precipitate on the surfaces, a larger type of globules, probably a calcium fluoride like product, and a smaller type of globules, probably a tin phosphate. The aim of the present study was to examine the amino acid composition and the formation of the acquired pellicle on SnF2-treated enamel in vivo.

Survival analysis of amalgam restorations in long-term recall patients.

The longevity of amalgam restorations in premolars and first and second molars in long-term recall patients has been calculated by means of survival analysis. The present retrospective longitudinal study includes information from 32 patients and their records over a time period of 17 years. The data were recorded by six dentists.

Effect of sodium lauryl sulfate on protein adsorption to hydroxyapatite in vitro and on pellicle formation in vivo.

Sodium lauryl sulfate (SLS) is widely used as a synthetic detergent in dentifrices. It has been shown to have high affinity for hydroxyapatite (HA), and the binding mechanism has been proposed to be electrostatic, involving the negative sulfate terminals of the SLS and the calcium sites on the HA. The binding of SLS to HA may thus well interfere with the protein adsorption to HA.

Interindividual and longitudinal studies of amino acid composition of pellicle collected in vivo.

The formation of the acquired enamel pellicle is due to the adsorption of salivary proteins to the enamel surface. This adsorption is assumed to be specific and is dependent on the chemical characteristics of the surface. The aim of the present study was to investigate the consistency of the chemical composition of the acquired pellicle collected in vivo.

Protein adsorption to hydroxyapatite and to calcium fluoride in vitro and amino acid analyses of pellicle formed on normal enamel and on calcium-fluoride-covered enamel in vivo.

Fluoride treatment of enamel has been reported to result in the formation of a layer of a CaF2-like material on the enamel surface. Protein adsorption to enamel is a specific process dependent on the nature of the surface, and little is known about protein adsorption to CaF2. Albumin and lysozyme were adsorbed to hydroxyapatite (HA) and CaF2 powder in vitro, and protein adsorption patterns constructed.

Effect of pyrophosphate on protein adsorption to hydroxyapatite in vitro and on pellicle formation in vivo.

This study showed that pyrophosphate (PP) desorbed an acidic protein (albumin) from hydroxyapatite (HA) more effectively than phosphate and that HA pretreated with PP took up markedly less protein than untreated HA. The protein which adsorbed to PP-treated HA was more loosely bound than that adsorbed to untreated HA. In vivo experiments showed that pellicle formed more slowly on PP-treated etched enamel than on untreated controls.

Chemical and morphological studies of the acquired pellicle formed subgingivally on dentin in vivo.

The morphological appearance and chemical composition of the subgingival pellicle were studied, using Auger analysis and scanning and transmission electron microscopy. A pellicle was formed on pieces of dentin (2 X 2 X 1 mm), prepared from freshly extracted teeth after root planing. The dentin slabs were inserted for 2 h into healthy gingival sulci.

Effect of sucrose rinses on bacterial colonization on amalgam and composite.

The effect of sucrose rinses on the bacteriology of early plaque on enamel, amalgam and composite was investigated. Three test persons rinsed with a 15% sucrose solution every hour for 12 h prior to the insertion of the test materials. Round disks of amalgam and composite were carried on the buccal surfaces of the upper molars for 2 1/2 h.

Is sulphated blood-group substance in pancreas a factor in cystic fibrosis?

The present study showed that the pancreas of two monkey species contained sulphated blood-group substance. Such strongly anionic molecules are known to bind calcium, and their solutions form gels in the presence of cations. It is suggested that such a mechanism may be involved in cystic fibrosis.

Furfurals in chlorhexidine-discolored pellicle.

The purpose of the present study was to investigate the possible presence of furfurals in chlorhexidine-discolored pellicle. Pellicle material was scraped off teeth and hydrolyzed in sulfuric acid and the hydrolysate then extracted with ether and examined by thin layer chromatography and gas chromatography-mass spectrometry. The presence of furaldehyde in discolored pellicle was demonstrated by these methods.

Chemical analysis of a sulphated macromolecule isolated from rabbit submandibular gland.

Chemical analysis of a sulphated macromolecule isolated from the rabbit submandibular gland showed that about 70 per cent of the dry weight could be accounted for in terms of amino acids of which the acidic amino acids, proline and alanine were the most abundant. Total carbohydrate was 11%. Galactose was the main neutral sugar but galactosamine, glucosamine, neuraminic acid, glucose and mannose could also be demonstrated.