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Biomedical subjects

W H Raab

Publications and source records attributed to W H Raab.

27 records · Page 2Linked to original sources
PubMed1990

[Pulp toxicity of the acid components of acid-base reaction cements].

Laser-Doppler-flowmetry enables us to assess microcirculatory changes in the tooth pulp. This method can also be used for testing the histocompatibility of dental materials. The acid components of Tenet and Ketac-Cem are examined for tissue tolerance. This is done by assessing the incisal and apical changes in pulpal microcirculation. The phosphoric acid of Tenet causes an almost complete collapse of the incisal microcirculation just a short time after its application. The tartrate of Ketac-Cem causes long-lasting hyperaemia, whereas the acryl-maleinate-copolymer has no discernible effects.

Animals↗
PubMed1989

[Temperature-dependent changes in the microcirculation of the dental pulp].

Laser Doppler flowmetry was used to study the changes in the blood flow within the dental pulp as a reaction to thermal stimuli between 17 degrees C and 57 degree C. Temperatures below 31 degrees C resulted in a reduction, temperatures above 43 degrees C in an increase in blood flow. Temperatures higher than 49 degrees C caused irreversible damage to the pulp's microcirculation. Experimental nerve blocks showed that the reactive increase is linked to the afferent rather than the sympathetic innervation of the tooth pulp.

Dental Pulp↗
PubMed1989

[Development of plasma extravasation in the dental pulp].

Recent studies suggest an active participation of postcapillary venules in inflammatory plasma extravasation. Intravital microscopic studies of rats' incisors show that Evans blue allows the demonstration of plasma extravasation in the dental pulp. This process takes place in the postcapillary venules, as can be seen from the staining of the interstice. Rather than depending on hydrodynamic pressure mechanisms, inflammatory plasma extravasation seems to be subjected to a direct regulation of vascular permeability.

Animals↗
PubMed1989

[Question of curative anesthesia].

As a method for keeping a tooth pulp vital that has undergone inflammatory alterations, curative anesthesia is controversial. Generally accepted ideas on the mechanism of action and on therapeutic concepts are lacking. Animal experiments using Laser Doppler flowmetry and intravital microscopy are to demonstrate that, under defined conditions, local anesthesia may reduce the effects of neurogenic pulpitis. A therapeutic recommendation, however, cannot be given.

Anesthesia, Dental↗
PubMed1989

[Laser Doppler Flowmetry: microcirculatory studies in the dental pulp].

Laser Doppler Flowmetry permits studies of the blood circulation in circumscribed tissue areas. This measuring method may also be applied to the dental pulp if a suitable experimental design is developed. Incisor teeth of rats are used as an example to illustrate that a quantitative analysis of changes in the blood flow is possible with the aid of suitable preparation procedures.

Animals↗
PubMed1988

Changes in dental blood flow following electrical tooth pulp stimulation--influences of capsaicin and guanethidine.

The responses of rat incisors microcirculation to electrical pulp stimulation was examined. A fast initial decrease was followed by a long lasting increase in blood flow due to activation of sympathetic efferents and nociceptive afferents, respectively. Both constituents of the response could be abolished differentially by the use of guanethidine (sympathectomy) and capsaicin (C-deafferentiation), respectively. The results point to a role of both C-efferents and peptidergic C-afferents in the control of tooth pulp circulation.

Animals↗