PubMed HealthSearch

Biomedical subjects

F Fløystrand

Publications and source records attributed to F Fløystrand.

5 recordsLinked to original sources

A method for testing denture adhesives.

An in vitro test method is described simulating the in vivo fate of a denture adhesive, i.e., destruction of the adhesive, dilution, and dissolution, by measuring the bond strength for the adhesive placed between acrylic resin plates. Between each measurement, the adhesive was exposed to isotonic saline. The bond strength for two ointment denture adhesives, Super Corega and Fixodent, was measured and the results were compared with those obtained for one of them in a previous in vivo test. The test method described for denture adhesives seems useful to depict the fate of a denture adhesive in clinical use.

Adhesives

The masseteric reflex evoked by tooth and denture tapping.

The characteristics of the masseter reflex evoked by tapping a maxillary incisor were compared with the reflex pattern evoked by tapping a corresponding denture tooth after insertion of an immediate denture. Up to three inhibitory phases (I-1, I-2 and I-3), followed by excitation, were found on an averaged EMG. The tapping force threshold for the early inhibitory phase was lower than for the late phases. The pattern of the reflex was generally the same before and after insertion of the denture, but the threshold values increased. After insertion of the denture, the threshold for I-1 increased from 1 +/- 0.3N to 2.2 +/- 0.4N, the threshold for I-2 increased from 2.4 +/- 0.8N to 3.8 +/- 0.9N, and the threshold for I-3 increased from 5.1 +/- 0.6N to 8.3 +/- 0.9N. The latency period for I-1 also increased from 12.3 +/- 0.5 ms to 13.1 +/- 0.3 ms after insertion of the denture. After relining, the threshold for evoking I-1 decreased from 2.7 +/- 1.2N to 1.2 +/- 0.6N. It was assumed that the mechanoreceptors situated in the mucosa under the denture base could take over the functional role of the periodontal mechanoreceptors for evoking the masseter reflex during tapping, and that these afferents probably had connections to the same interneurones.

Denture, Complete

Vestibular and lingual muscular pressure on complete maxillary dentures.

Denture retention may be defined as the ability of a denture to remain seated on the supporting tissues under various conditions. Soft tissue function influences the retention of removable prostheses by exerting pressure against the polished surfaces. The magnitude of this pressure on complete maxillary dentures under experimental conditions was studied. Five denture wearers participated. Miniature pressure transducers were placed at nine selected locations on the polished surfaces of the dentures: one on each tuberosity, three along the vibration line, and four on the vestibular flanges. The transducers were flush with the polished surfaces but discernible to the participants. Ultra-thin electrical wires connected the transducers to a power supply and recording equipment. Loading the incisors with 40 N in a cranial direction elicited soft-tissue pressure against the transducers. The highest values were recorded in the region of the tuberosities (51 kPa). Intermediary values were recorded along the vibration line (27 kPa), and the lowest pressure was recorded on the vestibular flanges (17 kPa).

Aged

Effects on retention of reducing the palatal coverage of complete maxillary dentures.

Twenty patients with complete dentures in both jaws gave up their maxillary ones for experimental purposes for 4 weeks while new dentures were made. The experimental dentures were reduced palatally to a new U-shaped border situated approximately 10 mm from the dental arch. Denture retention, defined as the ability of a denture to remain seated on the supporting tissues under various conditions, was measured as resistance towards cranially directed tilting loads, using a miniature bite force recorder. Dislodgement-provoking loads were applied to the first bicuspid on both sides and to the central incisors. The retention measurements were performed before and immediately after reduction of the palatal coverage and, finally, after 4 weeks. Interview questions were posed concerning the subjects' experience of denture retention and some other aspects of oral comfort. The interviews were carried out before reduction of the palatal coverage and after 2 and 4 weeks. The results of the experimental dislodgement tests suggested that the ability to withstand tilting loads was insignificantly altered by reduction of the palatal coverage. This finding was in agreement with responses indicating that retention during meals remained unchanged. However, several individuals reported that denture retention between meals was impaired. Three denture wearers reported that reduction of the palatal coverage influenced their sense of taste positively, and one reported that an occasional gagging tendency had disappeared. At the end of the experiment the participants were given the choice of a new conventional denture or a new denture without palatal coverage.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged

Pathologic attrition and maximal bite force.

The maximal bite force was recorded between antagonizing anterior teeth in a group (n = 10) of patients with pathologic attrition and in a control group. No statistically significant difference between the maximal bite forces was recorded. Also, the effect on the maximal bite force of the continuous wearing of a partial bite raising splint for 4 months was recorded. The great individuality in reaction patterns prohibited simple generalizations. However, in some individuals the maximal bite force was larger when biting on the splint than without, both at base line and after 4 months. Also, the maximal bite force showed a tendency to increase with time. The findings indicate that pathologic attrition is not necessarily associated with a high maximal bite force. Also, the maximal bite force recorded under various conditions is seemingly not an absolute value but rather the result of a number of factors of varying importance for different individuals.

Adult