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Biomedical subjects

C Bruun

Publications and source records attributed to C Bruun.

33 records · Page 2Linked to original sources
PubMed1979

Fluoride concentrations in saliva in relation to chewing of various supplementary fluoride preparations.

Fluoride concentrations were measured in whole saliva samples collected from 16 subjects at different intervals up to 60 min after chewing of various supplementary F preparations: chewable F tablets (0.21 mg F), plain F tablets (0.25 mg F) or F-containing chewing gum (0.25 mg F). Each of the F preparations was administered in a low dose (0.21--0.25 mg F) or in a high dose (0.42--0.50 mg F). Mean resting levels of fluoride in saliva ranged from 0.03 to 0.05 parts/10(6). Peak values averaging 15--25 parts F/10(6) in the low-dose group and 25--40 parts F/10(6) in the high-dose group were recorded within 5 min after intake. After 30 min, the salivary fluoride concentrations in both groups had decreased to levels below 1 part/10(6) and approached resting levels 60 min after intake. The availability of fluoride in saliva, as estimated from AUC values (areas under curves, relating fluoride concentrations to the time from 0 to 60 min), was similar with each of the preparations applied in the low dose. When used in the high dose, the chewing gum and also the plain tablets provided significantly more fluoride in saliva than the chewable tablets. The data may suggest that unflavored plain F tablets are equally suitable as a vehicle for fluoride aiming at a topical cariostatic effect as specially designed chewable tablets or chewing gum.

Chewing Gum↗
PubMed1978

Release of fluoride from fluoride-containing chewing gum.

The release of fluoride from fluoride-containing chewing gum and the fluoride concentration in whole saliva was measured at different intervals after the start of the chewing procedures. The residual fluoride contents were 78, 32, and 6% of the initial 0.25 mg in the gum after chewing for 2, 5, and 10 min, respectively. When chewing for 10 min, the salivary fluoride increased from 0.05 to 11.7 and 15.3 parts/10(6) after 2 and 5 min, respectively, followed by a fall to 3.9 parts/10(6) after 10 min. Concentrations exceeding the preintake level were still recorded 60 min after the start of the chewing.

Adult↗
PubMed1976

In vivo uptake of fluoride by surface enamel of cleaned and plaque-covered teeth.

Utilizing a newly developed biopsy method, the F uptake in the outer 3 mum of enamel from a single topical application of neutral NaF or amine F solution was tested on cleaned and plaque-covered premolars in 12- to 14-year-old children. Cleaned teeth treated with neutral NaF acquired only insignificant amounts of F. The presence of plaque seemed to enhance the deposition of F in surface enamel. The findings were discussed in relation to the possible mechanisms of action of topically applied fluorides. Topical treatments with amine F increased surface enamel F considerably more than the NaF. The F uptake was similar in cleaned and plaque-covered teeth. It was suggested that the usually performed plaque-removing procedures prior to topical F applications are superfluous and may even be disadvantageous.

Adolescent↗
PubMed1975

A field biopsy method for fluoride determinations in human surface enamel.

An enamel biopsy method was developed that is especially intended for use under primitive clinical conditions in field studies. Three successive enamel layers, each of 1 mum or less, were etched off the same delimited area of 3 mm2 by means of perchloric acid, using a microsampler with disposable tips. The biopsy technique was applicable to the vestibular surface of almost all teeth, causing no perceptible damage to the enamel surface. Based on cumulated data from the successive enamel layers, curves were drawn from which F levels at various depths in the outer 3 mum of the enamel could be interpolated. F levels in surface enamel of maxillary first premolars in 40 12-13-year-old children in a locale with 0.5 mg F/l in the drinking water were found to be 3,800, 2,400 and 2,000 parts/10(6) in three successive enamel layers of 0.6, 1.0 and 1.1 mum, respectively, demonstrating a decrease in F concentration of about 1,800 parts/10(6) within this depth interval. Identical F concentrations were found in bilateral premolars.

Adolescent↗
PubMedDate not supplied

Reconstruction of chronic insufficient anterior cruciate ligament in the knee using a synthetic Dacron prosthesis. A prospective study of 57 cases.

In this study, a total of 57 patients with rupture of the anterior cruciate ligament and persistent functional instability of the knee had their anterior cruciate ligament reconstructed with a Dacron prosthesis between November 1984 and February 1987. The patients, 43 males and 14 females with a mean age 26 years (range, 16 to 42), were followed for 2 to 4 years (mean, 34 months). In total, 30 patients had concomitant knee ligament or meniscal lesions. Postoperatively, the knee was not immobilized, but was actively trained in a cast brace. At followup, 54 of the patients were examined, and 71% had a good or excellent result according to the Lysholm score. The Tegner activity score improved in 33 patients and 15 achieved their preinjury sporting activity level. The instability, as measured by the anterior drawer sign and the Lachman test, declined from 3.3 to 2.1. Ten prostheses had ruptured at a mean of 11 months (range, 3 to 21). One patient had a deep postoperative infection, another developed chronic synovitis, and one incurred reflex dystrophic changes.

Adolescent↗