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Biomedical subjects

D A Falace

Publications and source records attributed to D A Falace.

23 records · Page 2Linked to original sources
PubMedDate not supplied

The effects of nitrous oxide administration in the healthy elderly: N2O elimination and alveolar CO2.

Healthy young and elderly males were administered sedative concentrations of nitrous oxide/oxygen (N(2)O/O(2)) under a protocol designed to mimic that used in a dental operatory. Samples of end-tidal expired gas were taken at the end of 30-minutes inhalation of, and periodically for 70 minutes after withdrawal from, nitrous oxide/oxygen. Samples were analyzed to monitor the decline of alveolar nitrous oxide levels and any changes in alveolar carbon dioxide levels, to determine if there were any age-related differences. The fall in alveolar N(2)O following cessation of administration was rapid, and in a double-exponental manner as was expected. No age-related difference in N(2)O decline was observed. Alveolar carbon dioxide (CO(2)) levels were lower and more variable in the elderly group. Both groups exhibited elevated CO(2) levels at the end of the N(2)O period, and an unexplained rise in CO(2) at approximately 30 min post N(2)O.

Adult↗
PubMedDate not supplied

Effect of age on the digit blood flow response to sedative concentrations of nitrous oxide.

Twenty healthy male subjects [11 young, x̄ = 25.4 ± 0.8 (SEM) years old; 9 elderly, x̄ = 64.5 ± 0.7 years] volunteered for a study designed to investigate the effect of age on several cardiovascular parameters to inhaled N(2)O-O(2). The protocol was designed to mimic the administration of N(2)O-O(2) for sedation in the dental office, although no dental treatment was performed. Clinical criteria were used to judge the appropriate sedative level for each subject; no attempt was made to establish doseresponse relationships. Digit blood flow was measured by strain-gauge plethysmography, and heart rate, arterial blood pressure, respiratory rate, and skin temperature were monitored and recorded. N(2)O and CO(2) levels were monitored in end-tidal gas samples by gas chromatography; machine gauge readings were calibrated against known gas mixtures by the same technique.Under the conditions of this experiment both healthy young and healthy elderly subjects experienced a marked (200-300%) increase in digit blood flow during N(2)O inhalation, compared to that during air and 100% O(2) inhalation. There was no significant difference in the degree of flow increase between young and elderly subjects. Also, there were no significant differences in the response of these healthy young and healthy elderly subjects to sedative concentrations of N(2)O with regard to heart rate, arterial blood pressure, respiratory rate, skin temperature, or mean end-tidal CO(2) levels. The data indicate that N(2)O, in the concentrations routinely administered in the dental office for sedation, does not have a differential effect on the measured parameters in healthy elderly and healthy young males.

Adult↗
PubMedDate not supplied

The effect of nitrous oxide and age on psychological and psychomotor performance.

Healthy older and younger males were compared on several psychomotor and cognitive measures before, during, and after N(2)O inhalation. Age did not appear to be a significant factor in determining response to N(2)O though on several measures younger subjects are superior to older under all conditions. N(2)O had a significant effect only on reaction time and facial recognition tasks. The relation of these findings to previous work is discussed.

Adult↗
PubMedDate not supplied

Modified overdentures for the management of oligodontia and developmental defects.

A technique for the construction of complete dentures over unaltered natural teeth has been described and illustrated for three different situations. The procedure is straightforward and simple and varies only slightly from conventional overdenture construction. The technique offers several advantages for a patient who wishes to keep the remaining natural teeth unaltered but who requires significant functional or esthetic improvement. Since the teeth are unaltered, any type of future treatment may be considered at any time without being compromised. This is an important factor to consider for the young patient. The cost, when compared to the fabrication of a fixed or cast removable prosthesis, is significantly less, while still providing acceptable esthetics and function. The versatility of this procedure allows its use in a number of situations which are not amenable to more complicated treatment methods.

Adolescent↗