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Biomedical subjects

B Angmar-Månsson

Publications and source records attributed to B Angmar-Månsson.

At least 55 records · Page 3Linked to original sources
PubMed1990

Automatic pH-cycling caries model applied on root hard tissue.

The development of a caries lesion is a dynamic process that includes frequently alternating periods of de- and remineralization, a process for which no in vitro models currently exists. The aim of this study was to develop a model which could repeatedly generate identical pH versus time curves over extended periods of time. To test the model demineralization studies on cementum/dentin were performed. Cementum/dentin blocks were repeatedly subjected to de- and remineralizing solutions delivered by a computerized pump system connected to a pH-meter and a recorder. pH versus time curves similar to those produced in plaque after carbohydrate intake were generated 18 times during 15 h followed by a remineralizing period of 9 h every day for 16 days. The intra-day and inter-day variation of the pH-cycling model were found to be low. The mineral change of the blocks was followed by 125I absorptiometry and the transmission through the blocks during the experimental period increased in average by 1.4 +/- (SE) 0.18%. Microradiographic analysis of the transversal sections of the blocks confirmed the development of lesions resembling root caries.

Absorptiometry, Photon↗
PubMed1990

Enamel and dentin fluoride levels and fluorosis following single fluoride doses: a nuclear microprobe study.

Female rats were given single intraperitoneal doses of fluoride (F) (0, 4, 7, or 14 mg F/kg body weight). Plasma F levels returned to predose values within 24 h. Incisors from animals killed 35 or 70 days after the F doses had been given were analyzed for mineralization defects by microradiography, and for F and P concentrations by nuclear microprobe. At 35 days, all F-injected rats had enamel fluorosis. At 70 days, by which time the incisors would have been renewed nearly twice, fluorosis was still evident in the 14 mg/kg body weight group. The enamel and dentin F concentrations at each time point were proportional to the administered F doses that had been given weeks earlier. The F concentrations at 35 days were similar to those found at 70 days. The results support the hypothesis that, following pulse loading, F can be mobilized from the bone adjacent to the enamel organ and result in local F concentrations sufficiently large to adversely affect amelogenesis.

Animals↗
PubMed1990

Environmental and physiological factors affecting dental fluorosis.

In addition to differences in fluoride intake and possibly to calcium deficiency or malnutrition, there are several factors which may account for individual differences in the occurrence of dental fluorosis. Disorders in acid-base balance affect the renal handling of fluoride such that, in acidosis, the excretion rate is diminished and, in alkalosis, the excretion rate is enhanced. Thus, any factor that can decrease urinary pH would be expected to increase the likelihood of dental fluorosis and vice versa. Results from studies with both rats and dogs have shown that acid-base disturbances per se, especially acidosis, adversely affect the mineralization of enamel in a manner that resembles fluorosis. It has been found that the retention and tissue levels of fluoride are increased by residence at high altitude. It has also been found that, in the absence of fluoride exposure, residence at high altitude per se can have a profound disruptive effect on amelogenesis which could be confused with fluorosis. The effects of diseases which lead to increases in urinary flow rate and water intake on the likelihood of the occurrence of dental fluorosis are also discussed.

Acid-Base Imbalance↗
PubMed1989

Relationship between oral symptoms, salivary function, smoking habits and general health in patients with complaints related to dental restorative materials.

Eighty consecutive patients, referred to the Department of Prosthetic Dentistry, Public Dental Service, Stockholm, for examination of complaints related to dental restorative materials or for supposed adverse effects from mercury released from dental amalgams were investigated. Clinical examination as well as battery of laboratory tests were performed. Statistical correlations were found between subjective and objective oral symptoms and lowered pH-values in stimulated saliva (p less than 0.001) as well as between objective oral symptoms only and lowered pH-values in stimulated saliva (p less than 0.001), which indicate salivary tests to be a useful tool when examining this type of patients.

Adult↗
PubMed1983

Fluoride concentrations in rat and human tooth pulps and their possible interference with phosphatase activities.

Alkaline and acid phosphatases (p-ases), fluoride (F), and calcium (Ca) were analyzed in the pulps of rat incisors and young human pre-molars. P-ase activities were about ten times higher in the rat than in the human pulps; in the latter, high p-ase activity appeared to be connected with rapid mineralization. Average total F was 3-4 ng/mg in both rat and human pulp, while Ca showed values several times higher, although greatly varying, in human than in rat pulps. Ionized F was two to three times higher in ultrafiltrates from rat and human pulps than in the blood plasma of the species; in the rat, the F content of the ultrafiltrates increased only three to four times when plasma F was experimentally elevated over 100 times. In vitro, rat pulp alk. p-ase activity was slightly inhibited only in the range above 100 mM NaF, while acid p-ase showed weak inhibition in the region from 0.15-0.25 mM and 40-60% inhibition in the range from 10-100 mM NaF. In vivo, no effect on pulp p-ases was found, even from sublethal NaF doses.

Acid Phosphatase↗
PubMed1976

Plasma fluoride and enamel fluorosis.

It is postulated that tissue fluid F concentrations are the primary determinants of flouride effects on bones and developing teeth and that these concentrations are dependent on, or mirrored by, blood plasma F. It has earlier been shown that the plasma F levels are dependent on the dietary F supply as well as on skeletal F concentration. Fasting and post-ingestion or postinjection plasma F levels have been determined in rats on F doses that cause different degrees of enamel fluorosis. The results indicate that temporary peak values rather than elevated fasting values are responsible for the occurrence of enamel fluorosis and that the peak values must approach about 10 muM in order to block enamel formation by the ameloblasts. The diagnostic and prognostic importance of plasma F determinations is discussed.

Amelogenesis↗
PubMedDate not supplied

Occlusal caries detection with KaVo DIAGNOdent and radiography: an in vitro comparison.

A new laser fluorescence method, KaVo DIAGNOdent, was tested with respect to reproducibility and validity and compared with radiography regarding accuracy in the detection of occlusal caries. Seventy-six extracted premolar and molar teeth were measured twice with DIAGNOdent under both wet and dry conditions, at an interval of 2 weeks. Conventional film radiographs were exposed. Microradiographic analysis of sections of the teeth served as the gold standard. Intra-class correlation coefficient and Pearson's correlation coefficient were used to assess the reproducibility and the validity of the method, respectively. The influence of time and varying humidities on DIAGNOdent readings were analysed by two-way repeated measure ANOVA. ROC curves were plotted for DIAGNOdent readings and radiographic registration of caries by 6 observers, and the areas under the curves were compared using Student's t test. Under both wet and dry conditions, the reproducibility of the DIAGNOdent method was excellent: R = 0.97 and 0.96, respectively. The diagnostic accuracy of DIAGNOdent was significantly better than that of radiography (p< or =0.001). In this in vitro study of detection of occlusal caries, the diagnostic performance of the DIAGNOdent method was superior to that of radiography.

Analysis of Variance↗
PubMedDate not supplied

Comparison of QLF and DIAGNOdent for quantification of smooth surface caries.

The aim was to compare the detection and quantification of smooth surface caries by KaVo DIAGNOdent and quantitative laser/light-induced fluorescence (QLF) using a laser and a lamp as two different light sources. On 40 premolar teeth extracted from adolescents, 71 non-cavitated approximal surfaces were assessed. For QLF, both mean and maximum fluorescence losses were registered. To provide a gold standard for verification, the teeth were then sectioned and lesion depth, stratified on a five-point scale, was determined by histopathology and microradiography. The correlation between the gold standard and the two methods was assessed by Spearman's rank correlation coefficient. The sensitivity and specificity of the methods for detection of smooth surface caries at D(3) level were also assessed. For lesion depth, correlation with the gold standard was similar for QLF and DIAGNOdent: about 0.85. With respect to dentinal caries detection, sensitivity for DIAGNOdent was 0.75 and specificity 0.96, with a cut-off point of 9. The corresponding values for QLF were 0.94 and 1, with a cut-off value of 20% of fluorescence loss. Spearman's rank correlation coefficients for enamel mineral loss and QLF and DIAGNOdent, respectively, were 0.76 and 0.67. It was concluded that for quantification of smooth surface caries, the methods are of equal merit, but for scientific purposes, QLF offers the advantage of closer correlation with changes in mineral content.

Adolescent↗