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Biomedical subjects

K W Frisken

Publications and source records attributed to K W Frisken.

11 recordsLinked to original sources
PubMed2002

A study of titanium release into body organs following the insertion of single threaded screw implants into the mandibles of sheep.

BACKGROUND: Titanium is generally considered a safe metal to use in implantation but some studies have suggested that particulate titanium may cause health problems either at the site overlying the implant or in distant organs, particularly after frictional wear of a medical prosthesis. It was the purpose of this investigation to study the levels of dissemination of titanium from threaded screw type implants following placement of single implants in sheep mandibles. METHOD: Twelve sheep were implanted with a single 10x3.75mm self-tapping implant for time intervals of one, four and eight to 12 weeks. Four unoperated sheep served as controls. Regional lymph nodes, lungs, spleens and livers were dissected, frozen and subsequently analysed by Graphite Furnace Atomic Absorption Spectroscopy. RESULTS: Results associated with successful implants showed no statistically significant different levels of titanium in any organ compared to controls, although some minor elevations in titanium levels within the lungs and regional lymph nodes were noted. Two implants failed to integrate and these showed higher levels of titanium in the lungs (2.2-3.8 times the mean of the controls) and regional lymph nodes (7-9.4 times the levels in controls). CONCLUSIONS: Debris from a single implant insertion is at such a low level that it is unlikely to pose a health problem. Even though the number of failed implants was low, multiple failed implants may result in considerably more titanium release which can track through the regional lymph nodes. Results suggest that sheep would be an excellent model for following biological changes associated with successful and failed implants and the effect this may have on titanium release.

Animals↗
PubMed1991

Clinical and microbiological investigations of anorexia nervosa.

Several studies have examined the relationship between anorexia nervosa and oral status. However, none has used control subjects. Furthermore, none has examined bacteriological data in these subjects to determine whether dietary restrictions, particularly of carbohydrates, change the levels of Streptococcus mutans and Lactobacillus species. Fifteen female subjects recently hospitalized for anorexia were studied along with fifteen age- and sex-matched control subjects. The parameters examined included salivary pH and flow rate, levels of S. mutans and Lactobacillus spp., DMFT scores, facial and palatal plaque scores, periodontal pocketing, gingival recession and bleeding following gentle probing. Compared with control subjects, anorexics had significantly lower salivary pH (7.1 +/- 0.4 vs 7.6 +/- 0.3, p less than 0.01), more facial and lingual surfaces with plaque scores of 1 (facial plaque 38 per cent vs 18 per cent, p less than 0.01, lingual plaque 47 per cent vs 29 per cent, p less than 0.01), more surfaces with gingival recession (1 mm-7.9 per cent vs 1.8 per cent, p less than 0.001; 2 mm-1.7 per cent vs 0.2 per cent, p less than 0.001; greater than 2 mm-0.6 per cent vs 0.0 per cent, p less than 0.001), more surfaces with bleeding on probing (16.9 per cent vs 6.5 per cent, p less than 0.001) and fewer sextants with CPITN scores of 0 (1.9 +/- 1.5 vs 3.2 +/- 1.0, p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1990

The incidence of periodontopathic microorganisms in young children.

Thirty-six children in 4 cohorts of 0-1 week, 1-6 months, 1-2 years and 2-2 1/2 years of age were examined for the presence of black-pigmented Bacteroides species and some other bacteria suspected of being involved in the subsequent development of periodontal destruction. None of the sought-after bacteria were detected in the first week of life. Bacteroides intermedius and Bacteroides melaninogenicus were detected as early as 1 month after birth. Both of these bacteria were detected in 16-37% of children in the different cohorts. Bacteroides denticola was detected in one child. Other black-pigmented species including Bacteroides gingivalis and Bacteroides loescheii were not detected. Eikenella corrodens was detected in 62% of children under 6 months. Capnocytophaga spp. were detected in 12% and Fusobacterium nucleatum in 25% of children in this age group. With increasing age there was a trend towards an increase in the number of children with F. nucleatum but other bacteria were detected in similar numbers of children throughout the 3 older cohorts. Actinobacillus actinomycetemcomitans was not detected at any age.

Age Factors↗
PubMed1989

Environmental influences on the progression of clinical and microbiological parameters of sheep periodontal disease.

The responses of some clinical and microbiological parameters of periodontal disease (PD) in sheep were examined subsequent to transferring animals between PD-affected and PD-free farms. Previously healthy animals showed transient deterioration in some clinical, but not microbiological parameters, which suggests either that a different microbiota to the one studied may be more important in the initiation of the disease, or that sampling did not intercept periods of destructive disease activity in the early lesions. In sheep with established disease, those parameters indicative of periodontitis which included pocket depth and bleeding on probing as well as the proportions of black-pigmented Bacteroides species were not significantly altered by environmental changes. This observation suggests that once the disease is established on PD-affected farms, the hand, some clinical signs of the disease including lengthening and mobility of incisor teeth increased in sheep on the PD-affected farm relative to the PD-free farm. This suggests that the disease may have a complex aetiology.

Animals↗
PubMed1988

A study of periodontal disease in sheep over a twelve month period.

Sheep affected by broken mouth periodontal disease (P.D.) were examined over a twelve month period for different clinical parameters. It is suggested that P.D. in sheep is an episodic phenomenon similar to human P.D., and that only a few animals with signs of P.D. may undergo clinically significant destruction over a yearly period. No single parameter could reliably predict future deterioration in other parameters.

Journal Article↗
PubMed1987

Suspected periodontopathic microorganisms and their oral habitats in young children.

Samples of subgingival plaque from 67 children, 5-7 years of age, were examined for the presence of certain suspected periodontal pathogenic species using the conventional technique of anaerobic sonification, dilution and spiral plating. When this technique was compared with a direct plating procedure which involved no preliminary dispersion and dilution of plaque specimens, it was found that the direct method resulted in double the frequency of children in whom black-pigmented Bacteroides (BPB) were detected and a 10-times increase in the number of subjects harbouring Actinobacillus actinomycetemcomitans. Samples from the tongue, tonsils and saliva were also plated using the direct technique. BPB were detected less commonly in the plaque specimens (61.3% of children) than in saliva (89.5%), or on the tongue (86.6%) and tonsils (97.1%). Expressed as percentages of a pooled sample of the total BPB population, the most frequently detected species in plaque were Bacteroides intermedius (44.4%) and Bacteroides melaninogenicus (48.0%). The most prevalent isolate in all other oral sites was B. melaninogenicus. Expressed as percentages of children in whom BPB were detected, the most frequently isolated species from plaque using the conventional dilution technique was B. intermedius (21.3%), whereas other BPB species were present in fewer than 5% of children. Fusobacterium nucleatum and Capnocytophaga species were isolated most frequently from plaque but were also commonly detected in the various other oral sites.

Aggregatibacter actinomycetemcomitans↗