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Biomedical subjects

B Nyvad

Publications and source records attributed to B Nyvad.

41 records · Page 3Linked to original sources
PubMedDate not supplied

Prospective study of the effect of post-brushing rinsing behaviour on dental caries.

Previous studies have indicated that rinsing the mouth with a beaker of water after toothbrushing may compromise the caries reducing effect of fluoride toothpaste. A 3-year clinical trial of daily supervised brushing with fluoride toothpaste at school was used to test the effect of post-brushing rinsing with water on caries increment. A total of 407 children, mean age 11.8 years, attending three schools in Kaunas, Lithuania were enrolled following informed consent of the children and their parents. Caries was recorded at baseline and annually for 3 years. During the study, children in two schools (A and B) performed daily supervised brushing with a 1,500-ppm fluoride toothpaste. Children in school A rinsed their mouths thoroughly with a beaker of water after toothbrushing whereas children in school B were only permitted to spit out once after brushing. Furthermore, the children in these schools were supplied with toothpaste and toothbrushes for use at home and in school. A third school (C), without daily brushing and without supply of toothpaste, served as control. Compliance with the protocol was consistently better in school B. After 3 years 276 children were available for examination. Three-year DMFS increments, including non-cavitated lesions (mean, 95% CI), were: school A, 6.8 (5.3; 8.3); school B, 6.2 (4.6; 7.8), and school C, 12.4 (10.6; 14.1). Mean increments for schools A and B did not differ significantly but were both significantly lower than those of school C (p< 0.001). It is concluded that post-brushing rinsing with water, under the conditions of this study, does not significantly affect the caries reducing effect of a fluoride toothpaste.

Analysis of Variance↗
PubMedDate not supplied

Diagnosis versus detection of caries.

Caries diagnosis is the art or act of identifying a disease from its signs and symptoms. This is distinct from the detection of the signs and symptoms themselves. The diagnosis forms the basis for making informed treatment decisions. Hence, if there is no diagnostic step expressed in terms of the probability of present and future occurrence of disease, practitioners may resort to treatments guided by previous experiences with similar clinical manifestations. This paper reviews various methodological aspects of caries diagnostic testing. It is concluded that rather than continuing to search for the truth of the diagnosis, it may be more informative to consider the consequences of the diagnosis. This view is supported by results from caries-preventive trials in which the activity of carious lesions has been monitored longitudinally over years.

Decision Trees↗
PubMedDate not supplied

Effect of saliva composition on experimental root caries.

The aim of this study was to determine the effect of saliva composition on caries lesion development independently of the flow rate of unstimulated whole saliva (UWS) and other caries-related variables such as lesion progression time, oral hygiene level, and fluoride exposure. We hypothesized that this could be done by developing experimental root caries under carefully controlled conditions in situ in test subjects with UWS flow rates within a narrow window of normalcy. Fifteen female and 5 male subjects (66 +/- 6 years) were selected for the study according to their UWS flow rates between 0.2 and 0.4 ml/min. All subjects developed experimental root caries lesions during a 62-day period in which UWS as well as stimulated whole saliva (SWS) were repeatedly collected and analysed for flow rate, pH, buffer capacity, inorganic, and organic composition. Caries lesion development was determined by quantitative microradiography. The mean UWS flow rate was 0.30 +/- 0.05 ml/min. Significant negative correlations were obtained between UWS total phosphate concentration and mineral loss (DeltaZ; r(s) = -0.72, p < 0.001) and UWS total protein concentration and DeltaZ (r(s) = -0.70, p < 0.01). SWS and its constituents had only limited or no effect on DeltaZ. Qualitative UWS protein analysis (SDS-PAGE) revealed that subjects with low DeltaZ values had broader and more stained amylase bands than subjects with high DeltaZ values. These findings were confirmed quantitatively by HPLC. We conclude that, within a group of subjects with normal UWS flow rates, the UWS composition was more important for caries lesion development than the SWS composition. Furthermore, high UWS concentrations of phosphate, protein, and amylase were caries-protective.

Aged↗
PubMedDate not supplied

IgA1 proteases of oral streptococci: ecological aspects.

The ecology and identity of IgA1 protease-producing streptococci in the human oral cavity were studied in an attempt to obtain insight into the significance of IgA1 proteases for host-parasite relationships. Contrary to previous observations, a detailed taxonomic analysis of oral streptococci revealed that all strains of S. sanguis and S. oralis ("S.mitior") produced IgA1 protease. In addition, IgA1 protease activity was observed in some isolates of S.mitis. Of the streptococci that initiate plaque formation on dental enamel 88% (median value) had IgA1 protease activity. Low proportions of the streptococci that colonize the tongue and oropharyngeal mucosae produced IgA1 protease, in contrast to 60% of streptococci isolated from buccal mucosa. The IgA1 proteases from S. sanguis I-III, S. sanguis IV, S. oralis, and S.mitis were distinct as revealed by studies using enzyme-neutralizing antibodies.

Adult↗