Abrasive Micro-sampling Technique Research Articles

Magnesium and fluoride distribution in human cementum with age.

Sixty-two human teeth, obtained from subjects aged 11 to 80 years, were used to determine the magnesium and fluoride concentration and distribution with age in human cementum. Transverse sections were prepared from the root region of teeth. Samples, each 30 microm thick, were abraded in sequence from the cementum surface and the cemento-dentine junction by an abrasive micro-sampling technique. Magnesium concentrations were lower in the cementum surface, and increased towards the cemento-dentine junction (CDJ), while fluoride concentrations were higher in cementum surfaces and tended to decrease towards CDJ. Fluoride distribution patterns were similar to that reported earlier while average fluoride concentration increased with age, however, either no change or decreasing tendencies were observed with magnesium.

The cessation of fluoridated water administration and the fluoride distribution profiles in rat molar cementum.

The aim of this work was to obtain further information about the origin of fluoride profiles in cementum. Fluoride was administered to rats at varying doses (0.50, 100 ppm F in drinking water) and for different durations (4, 13 and 25 weeks). Fluoride distribution across the full thickness of molar cementum in rats was measured by means of an abrasive micro-sampling technique. The average fluoride concentrations in cementum increased significantly with increasing dose and duration of fluoride administration. The relative reduction of the average fluoride concentrations after cessation of fluoride administration was 94.2-36.5% at 50 ppm F and 62.2-49.2% at 100 ppm F in the outer layers (1-60 microns) and 91.5-24.1% at 50 ppm F and 74.1-7.6% at 100 ppm F in the middle (61-120 microns) layers of the cementum, respectively. The reduction rates were more closely related to the time intervals following cessation rather than fluoride concentrations in drinking water or specificity within the cementum. Two factors which may influence this are new cementum formation after withdrawal of fluoride and some fluoride release from cementum surfaces when the fluoride supply stopped. It was concluded that the cessation of fluoride administration reduced the fluoride concentration on the outer layers of cementum differing from bone where reduction occurs across the entire thickness.

Fluoride distribution in human dental calculus obtained from different sites on the tooth surface

We examined the site specificity of fluoride (F) distribution in human dental calculus. Teeth with supra- and subgingival calculus were obtained from patients who resided in non-fluoridated areas in Japan and China. Sequential layers of the dental calculus (30 microns thick) were abraded by an abrasive micro-sampling technique and fluoride and phosphorus in the powdered samples were analyzed. Fluoride concentrations were highest in the outer, lowest in the middle and intermediate in the inner layers of dental calculus in general. In the outermost layers fluoride concentrations were highest in calculus found near the tooth cervix both in supra- and subgingival calculus. Fluoride concentrations decreased markedly toward the apical region in subgingival calculus, while it did not change toward the incisal or occlusal region in supragingival calculus. In the inner layers, fluoride concentrations in both supra- and subgingival calculus were not affected by position on the teeth. Fluoride concentrations in subgingival calculus near the apex were lower than in supragingival calculus near the incisal or occlusal region. It was concluded that the fluoride concentrations differ in different regions of dental calculus, probably due to their different mechanisms of formation.

Effect of stopping fluoride administration on the distribution profiles of fluoride in three different kinds of rat bones.

The aim of this work was to explore the reduction of fluoride concentrations in the skeleton after stopping experimental fluoride administration. Fluoride was administered to the rats at varying doses (0, 50, 100 ppm in drinking water) and for different lengths of time (4, 13, 25 weeks). A series of fluoride concentrations across the full thickness of humerus, parietal bone, and vertebra arch in rats were measured by means of an abrasive micro-sampling technique. The distribution profiles of fluoride from periosteal to endosteal surfaces, which were apparently related to the histological structure of these bones, were U shaped in the humerus, V shaped in the parietal bone, and W shaped in the vertebra arch. The average fluoride concentrations in the bones increased significantly with each increasing dose and length of fluoride administration. The relative increments were similar between the different regions or the different bones. After stopping fluoride administration, on the other hand, the relative reduction of the average fluoride concentrations in the bones were 30-100%. They were greatly related to the length after stopping fluoride administration and the dose and length of fluoride administration, but also dependent upon the type of bone and the region examined.

Identification of tissue inhibitor of metalloproteinases-1 (TIMP-1) in human teeth and its distribution in cementum and dentine

An inhibitory activity toward matrix metalloproteinases such as interstitial collagenase,72-kDa gelatinase/type IV collagenase, and stromelysin-1 was detected in an EDTA extract of pulverized roots of human teeth, and identified as TIMP-1 by sodium dodecyl sulphate-polyacrylamide gel electrophoresis and immunoblotting. Distribution of TIMP-1 in human cementum and dentine was investigated by a sandwich enzyme immunoassay in combination with an abrasive microsampling technique. TIMP-1 could not be detected in cementum from some teeth but in others decreased from a fairly low value at the surface towards the cementodentinal junction. TIMP-1 concentrations in the dentine increased consistently from the cementodentinal junction toward the predentine. The average TIMP-1 concentration in the dentine (54.1 ± 18.5 pg/mg ± SE) was significantly ( P < 0.05) higher than that (9.6 ± 6.0 pg/mg ± SE) in the cementum.

Fluoride distribution in dentine and cementum in human permanent teeth with vital and non-vital pulps

Twenty-two selected permanent teeth [11 with vital pulps and 11 with non-vital (necrotic) pulps] were obtained from patients aged from 20 to 73 yr in Nagoya, Japan. Fluoride (F) profiles in tooth samples were examined by using an abrasive micro-sampling technique. F levels in the pulpal dentine were significantly higher in vital than non-vital teeth for each age group, although there were observed increases of F with age. In the cementum the F levels were strongly related to age and there were few differences in profiles and levels of F between vital and non-vital teeth. It was concluded that vital pulp is an important factor for the pulpal dentine to absorb fluoride.

天然フッ素地域と非フッ素地域からの成人のセメント質および象牙質のフッ素濃度分布

The purpose of the study was to examine the effect of water fluoride content on the fluoride profile across the entire thickness of the cementum and root dentine of human permanent anterior teeth using an abrasive micro-sampling technique (Weatherell et al. 1985). Twenty eight human permanent anterior teeth, aged from 30 to 60 years were analyzed. One group was obtained from a naturally fluoridated area (West-Hartlepool in the UK: fluoride content in drinking water 1.0-1.3 ppm) and the other from a non-fluoridated area (Leeds in the UK: fluoride content in drinking water is less than 0.1 ppm). A slice, about 300μm thick was prepared bucco-lingually on a slide of 28 human permanent anterior teeth. Each specimen was divided into 3 parts, one near thecement-enamel junction (CEJ), a second at the middle of the root dentine, and a third near the root apex. Using a thine diamond disk, parallel blocks of tissues about 1 mm wide were cut under a dissecting microscope. Layers of cementum and root dentine were abraded using abrasive micro-sampling until the pulpal surface of the root dentine was reached. Fluoride and phosphorus contents were determined for each sample. The results were as follows;1) Fluoride concentration was higher in teeth samples taken from the naturally fluoridated area (WHP) than from the non-fluoridated area (LDS).2) Average fluoride concentration and age had a positive correlation in WHP dentine middle region (r=0.79, p<0.001) and in the apex region (r=0.61, p<0.05), and in WHP cementum cervical region (r=0.67, p<0.01).3) An analysis of variance suggested that the area, age and number of years lived in the area combined with age were significant.We concluded that the WHP group had a higher fluoride concentration than the LDS group in cementum and root dentine throughout life, suggesting that topical and ingested fluoride application are effective in preventing adult root surface caries.

Fluoride uptake in human dentine from glass-ionomer cement in vivo

The purpose was to examine F uptake and distribution in dentine from a F-containing glass-ionomer cement in vivo. Nine volunteers were selected from dental students who were scheduled for extraction of their third molars. Two cavities were prepared on the same occlusal surface of the third molars for each subject; one was restored with glass-ionomer cement (Virtabond), the other with zinc phosphate cement as a control. After 3 months the teeth were extracted. F profiles in the dentine from the cavity floor to the pulpal surface were determined in tissue immediately adjacent to the restorations. An abrasive micro-sampling technique was used. The F concentration of the dentine was highest immediately beneath glass-ionomer cement filling, decreasing towards the pulpal surface. Overall F concentrations were greater in the dentine beneath the glass-ionomer cement than in that beneath the zinc phosphate cement. It was concluded that the glass-ionomer cement markedly enhanced fluoride uptake by underlying dentine in vivo.

Distribution profiles of fluoride in three different kinds of rat bones

The study was performed to reveal the detailed distribution profiles of fluoride in three different kinds of rat bone—humerus, vertebral arch, and parietal bone—and to compare this with the histological appearance of each bone type. Two groups of Wistar rats were provided water ad libitum containing 0 and 100 ppm fluoride, respectively, for 24 weeks. The fluoride distribution profiles across the bone of the three different bones from the outer to the inner surface were determined by means of an abrasive micro-sampling technique. In control animals, both humerus and parietal bones showed higher concentrations at the periosteal and endosteal surfaces, while the vertebral arch showed additional high levels in the middle (containing trabecular bone) of the tissue. In exposed animals, fluoride levels increased greatly in all three bone types. The vertebral and parietal fluoride distribution profiles were relatively unchanged, although humerus fluoride increased from periosteum to endosteum. The differences in fluoride distribution profiles were apparently related to the histological appearances of these bones. The surface area of bone available and the extent of vascularity appear to affect fluoride uptake.

Distribution of fluoride in cortical bone of human rib.

We describe a detailed study of fluoride distribution with age in the human cortical rib bone. Human ribs were obtained from 110 subjects (M:68, F;42) aged 20-93 years. The fluoride distribution from the periosteal to endosteal surfaces of the ribs was determined by sampling each specimen using an abrasive micro-sampling technique, and the samples were analyzed using the fluoride electrode, as described by Weatherell et al. [1]. The concentration of fluoride was highest in the periosteal region, decreased gradually towards the interior of the tissue where the concentration of fluoride tended toward the plateau, and then rose again towards the endosteal surface. Patterns of fluoride distribution changed with age, and the difference between periosteal and endosteal fluoride levels increased with age. Although average fluoride concentrations increased with age in both sexes, there was a significant difference between males and females at the age of about 55 years (P < 0.05).

Distribution of fluoride across human primary enamel

The distribution of fluoride was described in detail from the incisal to the cervical region in 10 pairs of primary lower central incisors. Fluoride analyses were done on the right incisors; optical microscopic studies were done on the left. The distribution data obtained from fluoride analyses of the right incisors were superimposed on micrographs of sections through the left incisors. An abrasive microsampling technique (Weatherell et al., 1985) was used to determine the fluoride concentration and distribution. Fluoride concentration was the highest at the enamel surface and decreased from there to the interior. The fluoride distribution did not level off to an even plateau in the enamel interior, as suggested by earlier studies. Apart from the high concentration in the surface region, the fluoride levels in prenatal and postnatal enamel were rather similar. The fluoride concentration tended to be low at the neonatal line.

Distribution of fluoride in sound and periodontally diseased human cementum

Abstract Fluoride distribution was investigated by an abrasive micro-sampling technique. The fluoride concentration increased with age in both sound and diseased cementum. In sound teeth, the fluoride profiles (distribution of fluoride from the surface to interior) of the middle and apical cementum were similar. In the diseased cementum the profile of the middle region tended to be more variable than that of the apical cementum, suggesting a possible effect of the oral environment on the fluoride profile at this site.

ヒトの骨におけるフッ素濃度分布と年齢的変化

There is little information about the pattern of fluoride distribution in human bones relative to sex and age. The present study is the first of its kind to be undertaken to determine in detail the fluoride distribution profile in human bone.Human ribs were obtained from 119 patients (M: 72, F: 47) aged 20 to 93 yrs. The fluoride distribution from the periosteal to the endosteal was determined in each specimen using the abrasive micro-sampling technique. Fluoride was determined using the fluoride electrode as previously described by Hallsworth, Weatherell and Deutsch (1976), and phosphorus was determined by the colorimetric procedure of Chen, Toribara and Warner (1956).The concentration of fluoride was highest in the periosteal layer and then decreased gradually towards the interior of the tissue. The amount of fluoride leveled off and then rose again just before the endosteal surface. The difference between periosteal and endosteal fluoride increased with age. Overall, fluoride concentrations increased steadily with age in male subjects but leveled off until the age of 55 yrs and then increased markedly in female subjects over the age of 55 yrs.

Distribution of fluoride concentration in the rat's bone

The present study was undertaken to determine the fluoride distribution profile in the rat femur. Male Wistar rats were divided into four groups and given water containing 0, 25, 50, and 100 ppm of fluoride, respectively, for 10 weeks. The fluoride distribution from the periosteum to the endosteum was determined in each specimen after sampling using the abrasive microsampling technique. In the outer circumferential lamellae, the concentration of fluoride was relatively high in the periosteal layer and then decreased gradually towards its interior. In the haversian and interstitial lamellae, it was lower and roughly constant through the tissue. In the inner circumferential lamellae, it rose again to reach the highest level towards the endosteal surface. Fluoride concentration throughout the cortex increased significantly with increasing intake of fluoride. These increases were especially marked at periosteal and endosteal surfaces.

Distribution of Fluoride across Cementum, Dentine and Alveolar Bone in Rats

This study was undertaken to determine the fluoride distribution in cementum and neighboring hard tissues of the rat after different levels of fluoride administration via the drinking water. Specimens of cementum with underlying dentine and adjacent bone were removed from the distal roots of the first lower molars. The fluoride distribution in each specimen was determined in samples removed sequentially using an abrasive microsampling technique. Fluoride concentrations were highest at or near the surface and decreased towards the interior of cementum, dentine and alveolar bone in both control and experimental groups. With increasing fluoride intake, concentrations increased throughout the tissue. The distribution patterns of fluoride in cementum of contralateral teeth from the same animal were similar. Fluoride concentrations in cementum were higher than those of dentine and alveolar bone.

ヒト乳歯セメント質におけるフッ素濃度分布

There is no information about the fluoride distribution in human deciduous cementum, although that of human permanent teeth was recently reported in detail. This study was undertaken to determine the fluoride distribution in human deciduous cementum, comparing the profiles of fluoride concentration in right and left teeth. 10 pairs of sound deciduous canines extracted from subjects aged 6-9 were examined. The teeth were sectioned and cementum specimens were removed from the buccal or lingual surface of sections. The fluoride concentration in each specimen was determined in samples removed sequentially from the root surface to the cementum-dentine junction, using an abrasive microsampling technique. The fluoride and phosphorus contents of each sample were determined and fluoride concentrations were calculated from the F : P ratios obtained. The concentrations of fluoride were highest at or near the cement surface and decreased towards the interior. On the other hand, the distribution patterns of fluoride in contralateral teeth from the same subject were roughly similar, although the concentrations and patterns of fluoride were different in each subject. It was concluded that each individual has a characteristic fluoride distribution in the deciduous cementum.

Distribution of fluoride in the enamel of rat incisors examined by an abrasive microsampling technique

This study was undertaken to reveal detailed changes in fluoride distribution at different developmental stages of upper incisor enamel under various fluoride administration regimes. Four groups of Wistar rats received water containing 0, 25, 50 and 100 parts/10 6 fluoride respectively for 10 weeks. Five different enamel specimens were removed from the developing enamel, excluding the matrix-formation stage. Fluoride distribution in each specimen was analysed from the surface to the enamel-dentine junction using an abrasive microsampling technique. Fluoride concentration was invariably highest at the surface and decreased sharply towards the interior at every site in both control and experimental groups. The concentration throughout the tissue increased with fluoride intake at each stage of development. The fluoride-gradient curves were similar at each of the different sites of tooth development. However, the fluoride concentration of the enamel interior was significantly higher at early maturation than at the other four sites.

Effects of Trigeminal Tractotomy and of Carbamazepine on Single Trigeminal Sensory Neurons in Cats

An improved enamel abrasive microsampling technique with an electronic preset counter and comparator has been designed. In vivo enamel microsamples were obtained from 30 incisors and premolars. The results showed low coefficients of variations for both enamel fluoride concentrations and depths of microsamples in vivo.