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Biomedical subjects

G Frostell

Publications and source records attributed to G Frostell.

At least 37 records · Page 2Linked to original sources
PubMed1980

The release of fluoride from two products of alginate impression materials.

The purpose of this study was to determine the fluoride content of two products of alginate and the possible fluoride transfer to the teeth, saliva and blood. The total fluoride content of Zelgan normal-set and Kerr alginate fastset powder was assayed by direct diffusion and diffusion of the ash. The soluble fluoride leaching out in water over 24 hour was also determined. The results show that the fluoride contents of Zelgan and Kerr alginate powders are about 1.9% and 1.5% fluoride, respectively. Of the fluoride present in Zelgan and Kerr approximately 6.5% and 5.8%, respectively, leached out in 400 ml deionized water. The fluoride uptake was estimated in two adjacent enamel layers each approximately 7 micrometers thick, using 10 teeth exposed for 5 minutes and 18 h to the alginate gel (Zelgan). The results of acid etch microsamplings indicate a significant increase in the fluoride concentration of the first enamel layer after both 5 min and 18 h exposure. Fluoride uptake within the second enamel layer was insignificant, however. Fluoride transfer to the oral saliva and to the blood was evident after impression taking.

Alginates↗
PubMed1980

A colourimetric screening test for evaluation of the buffer capacity of saliva.

A colourimetric method for screening buffer capacity of mixed paraffin stimulated saliva in general practice is described. Mixed paraffin stimulated saliva (1.00 ml) is pipetted into a standard tube belonging to a commercial "saliva kit" (Dentobuff, Orion Diagnostics Ltd). The tube is sealed with a plastic stopper and vigorously shaken for 10 seconds. The stopper is then removed and carbon dioxide is allowed to evaporate for 2--5 minutes. The colour is compared with a scale graded from pH 3 to pH 6. The method was evaluated using 136 dental patients and dental students, and a number of dentists and nurses, and the results were compared with the generally accepted clinical method developed by Ericsson (1959). Several different nurses, dentists and dental students took part in registering the results. In four cases the results differed by more than +/- 2.0 pH units between the two methods and in another 18 by more than +/- 1.0 units. Of the 80 tests performed on no occasion was a person with a "low" salivary buffer capacity evaluated as "normal" or "good". There was no obvious systematic deviation between the two methods, provided carbon dioxide was allowed to evaporate for 2--5 minutes before reading the colour. A thorough examination revealed that at a final pH over 5.5 the method gives lower values than Ericsson's method because of retained carbonic acid, a fact which was considered to be of minor importance, clinically. The method was found to be easy to handle and rapid and the accuracy was considered adequate. It is advisable, however, to repeat the test once or twice because of biological variation and in doubtful cases if "intermediate" results are repeatedly found to send the patient to a clinic with facilities for a complete test.

Adult↗
PubMed1979

Effects of 3 months frequent consumption of hydrogenated starch hydrolysate (Lycasin), maltitol, sorbitol and xylitol on human dental plaque.

Lozenges containing hydrogenated starch hydrolysate (Lycasin), maltitol, sorbitol or xylitol were consumed 4 times daily during 3 months by 4 groups of persons (in all 85 subjects). In the maltitol-, sorbitol- and xylitol-group the plque wet weights were of the same magnitude before and after the test period. In the Lycasin-group, a higher value was found after than before the 3-month period (p less than 0.01). The acid production in suspensions of dental plaque material from Lycasin, maltitol and sorbitol expressed as per cent of that from glucose was approximately the same before and after the test period. From xylitol no acid production could be demonstrated either before or after the 3-month period. There were no statistically significant differences between the plaque pH-changes induced by rinsing with 50% solutions of Lycasin, maltitol, sorbitol or xylitol before and after the test period. However, there was a tendency (p less than 0.05) towards lower pH-values induced by the maltitrol and sorbitol rinse after the 3-month period compared with before. No difference in the relative numbers of facultative anaerobic streptococci. Streptococcus mutans or facultative anaerobic lactobacilli before and after the test period was found.

Adult↗
PubMed1978

Biochemical effects of and bacteriological response to sugar substitutes in the oral environment.

The problems of the biochemical effects of sugar substitutes and bacteriologic response to such substitutes in the oral cavity may fill a whole book. Therefore, considerable restrictions in the presentation are necessary. Noncaloric sweeteners and additives are not utilized by the oral microorganisms for metabolism and acid production and are therefore of minor interest in this connection. This presentation mainly concerns sugar alcohols and related substances, primarily sorbitol, xylitol and Lycasin. Monosaccharides and other saccharides are not dealt with in this presentation even if some of them are of considerable interest; for example fructose, invert sugar and others. Sugar alcohols are used as substitutes because they cannot be utilized by the vast majority of oral organisms for fermentation, acid production or production of polysaccharides. There is a risk that the oral flora will adapt to these products and that such a substitute, which is originally nonacidogenic, may subsequently be utilized for fermentation and may even induce dental caries.

Acids↗
PubMed1977

SIMS study of element concentration profiles in enamel and dentin.

The ion probe technique has been employed for the determination of the concentrations of P, F, Cl, C, Na, K, Mg, Sr, Al, and Si at different depths in human tooth. The applicability of the method depends selectively on the element's position in the periodic table, but may be regarded as good for a wide range of microelements of dental interest.

Dental Enamel↗