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Biomedical subjects

T Imfeld

Publications and source records attributed to T Imfeld.

At least 55 records · Page 3Linked to original sources
PubMed1989

Cariological assessment of leucrose [D-glucopyranosyl-alpha(1----5)-D-fructopyranose] as a sugar substitute.

Leucrose [D-glucosyl-alpha(1----5)-D-fructopyranose] prepared by microbial-enzymatic transglycosidation from sucrose, is the first alpha(1----5)-linked disaccharide which possesses excellent nutritional properties with regard to metabolic utilization and is well tolerated. The aim of the present work was to assess its cariogenic potential. Yeast invertase was shown to be inhibited by leucrose in a noncompetitive way, while hydrogenated leucrose (leucritol) acted as an activator. Plaque polysaccharide forming glucosyltransferases from Streptococcus cricetus AHT were not influenced by leucrose, but by leucritol. Essentially no acid formation was observed after incubation of leucrose with suspensions of human dental plaque, S. mutans NCTC 10449, Lactobacillus casei LSB 132 and Actinomyces viscosus Ny 1 No. 30. Leucrose was a competitive inhibitor of the acid formation from sucrose by S. mutans NCTC 10449 at neutral pH. Furthermore, leucrose inhibited at neutral pH considerably the uptake of sucrose by S. mutans NCTC 10449. The uptake of fructose and maltose was also inhibited but that of glucose not at all. In Cara rats as the animal model, leucrose was compared to sucrose and to corn starch for its cariogenic potential. In sharp contrast to the group fed with 30% sucrose, caries scores of the 30% leucrose group were not significantly different from the starch group. pH telemetry with an indwelling electrode in man proved lueucrose to be 'safe for teeth' since plaque pH did not drop below pH 5.7. Leucrose is a novel noncariogenic disaccharide and thus represents a highly promising sugar substitute for caries prevention.

Actinomyces↗
PubMed1989

[Dental calculus-inhibiting tooth pastes and mouthwashes. A review of the literature of clinical trials].

Several brands of anticalculus dentifrices and mouthrinses claim to reduce the formation of supragingival calculus. These products contain soluble pyrophosphates (with or without Gantrez), zinc citrate trihydrate or zinc chloride which reduce the amount of supragingival but not subgingival calculus after a scaling. Most of the clinical anticalculus trials ran for 3 or 6 months and the calculus reductions were assessed using the Volpe-Manhold Index. This index assesses the coronal extension of supragingival calculus. Calculus reductions varied from 9% to 50% but no plaque scores were quantitated. However, the ADA has stipulated that dentifrices claiming anticalculus effects must clearly state that the products have not therapeutic effect on periodontal diseases. Some of the placebo dentifrices used in the clinical trials also reduced the calculus scores although they are not as yet advertised as anticalculus dentifrices.

Clinical Trials as Topic↗
PubMed1989

Dentin abrasion (RDA), enamel abrasion (REA) and polishing scores of dentifrices sold in Switzerland.

Assessments of the abrasion of hard dental tissues produced by different dentifrices are usually carried out on extracted teeth in the laboratory. The tests most commonly used to measure dentifrice abrasion on dentin and enamel are the radiotracer (radio-active) and profilometry methods. The radiotracer dentin (RDA) and enamel (REA) abrasion scores of the 32 dentifrices were determined using the ADA specifications. RDA and REA scores are related to a standard abrasive, calcium pyrophosphate (Ca2P2O7), which is assigned a score of 100 for the RDA method and 10 for the REA method. The same abrasive was used as the standard in the enamel polish study and assigned a score of 100. The RDA scores of the dentifrices tested varied from 37 to 203, the REA scores from 1.0 to 11.7, and the polishing scores ranged from 19.63 to 96.88. Half the dentifrices tested had RDA scores below 100.

Dental Enamel↗
PubMed1989

No effect of waxed dental floss on enamel fluoride uptake or on enamel dissolution changes.

Enamel specimens were flossed in vitro with "waxed" dental floss and then treated with water, Act, Meridol, or Elmex Gel to evaluate the effect of "waxed" floss on the enamel fluoride uptake and on the enamel dissolution rate. The flossed and treated enamel was etched 4 times successively in 2N HCl for 5, 10, 15 and another 15 s. The concentrations of fluoride, calcium and phosphorus were assayed in the etching solutions. The enamel fluoride concentration was significantly increased in only the first layer of the Elmex Gel group compared to the other 3 groups. Respective etching depths were similar for the water, Act and Elmex Gel groups. However, the first layer in the Meridol group was less etched than that in the 3 other groups. This study showed that "waxed" dental floss did not compromise the fluoride uptake by surface enamel after treatment with a concentrated acidic topical fluoridating agent. Moreover, previously reported results showing that Meridol solution containing SnF2 and amine fluoride 297 significantly decreased the in vitro dissolution rate of enamel were confirmed by the present study. Even though the enamel was first treated with "waxed" dental floss, the SnF2/amine fluoride 297 still produced a decreased enamel dissolution rate.

Acid Etching, Dental↗