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Biomedical subjects

D M Clark

Publications and source records attributed to D M Clark.

100 records · Page 6Linked to original sources

Radioisotope determination of apical seal integrity of silver point-filled endodontic teeth after ultrasonic vibration.

Twenty-six human mandibular incisors with single root canals were instrumented and obturated with silver points and sealer. The efficacy of the initial seal was tested by immersion in radioiodine and counted for gamma radiation. Subsequently, the teeth were subjected to the vibration of an ultrasonic scaling device and reimmersed in the isotope so that the integrity of the apical seal could be re-evaluated as a function of increased radioiodine uptake and, thus increased gamma radiation. No significant difference was found after use of the Cavitron device.

Dental Calculus↗

Cognition-behaviour links in the persistence of panic.

The cognitive theory of panic disorder proposes that panic attacks occur as a result of an enduring tendency to misinterpret bodily sensations as a sign of imminent catastrophe such as a heart attack. The persistence of such catastrophic cognitions is in part due to the tendency of patients to avoid and/or escape situations where panic occurs. It is proposed that within-situation safety seeking behaviours also have the effect of maintaining catastrophic cognitions in the face of repeated panics during which the feared catastrophe does not occur. The association between catastrophic cognitions and within-situation safety behaviours matched the pattern predicted from the cognitive theory in 147 panic disorder patients. The implications of these findings for the way in which therapy is conducted are discussed.

Agoraphobia↗

Healing of canine autogenous cancellous bone graft donor sites.

Autogenous cancellous bone was procured from the proximal ends of one humerus and the contralateral tibia of eight adult mixed-breed dogs. Greater weights of bone were consistently harvested from the humerus than from the tibia. Restoration of cancellous bone was more rapid and complete in the humerus than in the tibia. The tibia harvest site filled primarily with fibrous tissue rather than with cancellous bone.

Animals↗