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Biomedical subjects

T Gotjamanos

Publications and source records attributed to T Gotjamanos.

At least 19 recordsLinked to original sources
PubMed1998

Abnormally high fluoride levels in commercial preparations of 40 per cent silver fluoride solution: contraindications for use in children.

Although a 40 per cent solution of silver fluoride would be expected to contain 6 per cent fluoride (60,000 ppm), F-levels of 100,000 ppm and 120,000 ppm were found in 14 commercial samples analysed at The University of Western Australia in 1993 and 1994. To determine whether F-levels in 40 per cent AgF preparations have remained high, the present investigation was aimed at analysing different batches of commercial preparations obtained more recently. Fluoride ion analysis was carried out on 24 AgF samples using the Ion-Selective Electrode technique. Independent analyses of the same samples were carried out by a private chemical testing laboratory (Genalysis). Ten samples supplied by Agson Chemical Export were found to contain between 75,000 and 100,000 ppm F-: Genalysis reported 80,000 to 120,000 ppm. Fourteen samples supplied by Southern Dental Industries were found to contain between 70,000 and 120,000 ppm F-; Genalysis reported 88,000 to 108,000 ppm F-. These results confirm significantly higher than expected F-levels (ANOVA p < 0.05) in commercial preparations of 40 per cent AgF. The solutions tested were found to contain a mixture of ammonium fluoride, sodium or potassium fluoride, and silver fluoride. The additional presence of silver difluoride and hydrofluoric acid resulting from the manufacturing process has been suggested as an explanation for the much higher than expected levels of fluoride ion. In view of possible toxicity of 40 per cent AgF in young children, it is concluded that such a highly concentrated solution should not be used clinically; instead, lower strength AgF solutions should be investigated for their efficacy in caries treatment.

Ammonium Compounds↗
PubMed1997

Unacceptably high levels of fluoride in commercial preparations of silver fluoride.

Instead of expected fluoride ion concentrations of around 60,000 ppm, commercial preparations of 40 per cent aqueous silver fluoride were found to contain 120,000-127,000 ppm. Information received from the Western Australian Chemistry Centre which provided independent confirmation of the higher than expected [F] indicates that the currently available commercial preparations contain silver difluoride rather than silver fluoride. In view of the potential of fluoride-containing products such as dentifrices (1000-1500 ppm F) and topical fluoride gels and solutions (6000-12,000 ppm F) to cause adverse effects if excessive quantities are ingested, any product that contains 120,000 ppm [F] should be regarded as carrying a high risk of toxicity when used on young children.

Australia↗
PubMed1997

Safety issues related to the use of silver fluoride in paediatric dentistry.

Due to its exceedingly high fluoride content, 40% silver fluoride solution has the potential to cause fluorosis when used in young children. In vitro testing conducted in the present investigation indicates that application of 40% silver fluoride to deep carious lesions or its use as a 'spot' application agent could result in 3 to 4 mg of fluoride reaching the systemic circulation. As scientifically-based clinical trials on the safety of 40% silver fluoride have not been conducted, it would be appropriate for it to be withdrawn from further clinical use until proper testing and evaluation have been carried out. In view of the possibility that lower strength solutions of silver fluoride (1-4%) may be just as effective as 40% in 'arresting' deep caries, testing should focus on such solutions, particularly as the potential for toxicity from their fluoride content would be reduced by a factor of 10-40.

Administration, Topical↗
PubMed1997

Paediatric dentistry discussion paper and case report. Management of small carious lesions in primary teeth: caries removal versus fluoride application and periodic 'observation' until exfoliation.

Differences in treatment rationale exist between dental practitioners with respect to the management of small carious lesions in primary teeth. Some do not consider it necessary to use a conventional restorative approach, preferring to apply topical fluoride and/or 'monitor' the lesion(s). This paper advocates the alternative approach which entails complete caries removal by mechanical means, the rationale being to eliminate the pool of cariogenic microorganisms and thereby protect sound teeth from succumbing to carious attack. A case is presented to illustrate the extent to which caries can progress and also involve other teeth if small cavitated lesions are simply treated by 'spot' application of fluoride. Clinical treatment of caries must be based on scientific knowledge of the microorganisms involved and an understanding of its transmissible and infectious nature.

Child, Preschool↗
PubMed1996

Pulp response in primary teeth with deep residual caries treated with silver fluoride and glass ionomer cement ('atraumatic' technique)

Histological assessment of the dental pulps of 55 carious primary teeth was carried out 3 to 58 months after treatment by the 'atraumatic' technique involving application of 40 per cent silver fluoride to residual caries followed by restoration with glass ionomer cement. Fifty of the 55 teeth examined showed a favourable pulpal response, inducing presence of abundant reparative dentine and a wide odontoblast layer. Histological comparisons were made between these teeth and others not treated with silver fluoride but restored with glass ionomer cement, amalgam or zinc oxide and eugenol. Possible mechanisms of the action of silver fluoride in arresting residual caries are discussed. The question of whether or not treatment of carious dentine with silver fluoride represents a biologically acceptable clinical procedure cannot be answered on the basis of pulpal histology alone. The very high concentration of fluoride in commercial preparations of silver fluoride raises several questions concerning its clinical safety.

Adolescent↗
PubMed1996

An in vitro study of the distribution of silver and fluoride following application of 40 per cent silver fluoride solution to dentine.

An in vitro test system involving application of 40 per cent silver fluoride solution to prepared cavities of moderate depth in extracted teeth failed to demonstrate the passage of significant amounts of fluoride into the dental pulp, despite a very high concentration of fluoride (100,000 ppm) in the applied solution. The test system used may not be conducive to quantitative investigation of ionic transfer because of disruptions to pulp circulation and fluid flow through dentine following tooth extraction. For this reason, the results are inconclusive as to whether or not application of 40 per cent silver fluoride as a cavity varnish of liner and its use in the 'atraumatic' technique for treating deep caries, can be considered safe clinical procedures.

Adolescent↗
PubMed1992

Choice of toothbrush: a survey of dentists' personal preferences and recommendations for patients.

Data on dentists' choice of toothbrush brand/type for personal use and their recommendations for patients were obtained by means of a questionnaire. Seventy-nine per cent of dentists surveyed received free samples, with Oral-B comprising 33 per cent of all such samples, followed by Colgate (16 per cent) and Tek (13 per cent). Fifty-three per cent of dentists surveyed indicated they used all free samples received. Sixty-two per cent of dentists do not consider that different brushes differ significantly in their plaque-removing ability. Therefore, while an effective toothbrushing technique is important, selection of the 'correct toothbrush' from the wide range available may not be critical. The results of the present investigation provide information that is relevant to dental health education and can be applied at the chairside as well as at the broader community level.

Adolescent↗
PubMed1990

Integration of basic biological sciences and clinical dentistry in the dental curriculum. A clinically orientated approach to teaching oral and dental anatomy.

Although dental curricula have undergone significant revision during the past three decades, the problem of linking basic science with clinical dentistry often remains an unmet challenge in dental education. This paper describes the content and method of presentation of a course in oral and dental anatomy which aims to integrate closely basic biological science and clinical dental practice. The course holds considerable promise for overcoming one of the major deficiencies of the horizontally structured curriculum by presenting basic science information and detailing its clinical relevance simultaneously. The academic background, clinical experience, and educational philosophy of the course co-ordinator and assisting teaching staff are undoubtedly important factors in determining the extent to which integration between basic and clinical science can be achieved.

Anatomy↗
PubMed1986

Oral biology and the early introduction of clinical dentistry in the dental curriculum.

For the past nine years students entering the Dental School in the University of Western Australia have participated in an introductory clinical dentistry program closely integrated with oral biology. This paper outlines the content of the program and discusses its educational advantages. Changing attitudes in Australian universities toward the appointment of full professors in clinical disciplines also are discussed, and reference is made to the way in which these appointments are helping to achieve a closer correlation between basic science and clinical dentistry.

Anatomy↗
PubMed1981

The role of oral biology departments in dental education.

This paper defines the scope of oral biology, examines patterns of organization and staffing of oral biology departments, discusses the rationale for including courses in oral biology in the undergraduate curriculum, and the organization and content of such courses. Future trends in oral biology are outlined and the conclusion is reached that until clinical departments can assume primary responsibility for ensuring that basic sciences are adequately correlated with clinical dentistry, the need for an oral biology department within a dental school will continue to exist. Furthermore, departments of oral biology must collaborate closely with the clinical departments to develop unified teaching programs that encourage the use of basic science material in solving clinical problems

Biology↗
PubMed1979

Intracellular collagen in recurrent ameloblastic fibroma.

Electron microscopic examination of tissue from a twice recurrent ameloblastic fibroma revealed the presence of intracellular collagen fibres in fibroblasts active in protein synthesis. The intracellular fibres were morphologically identical to collagen fibres located extracellularly. The literature on intracellular collagen in biological systems and pathological states has been reviewed, and attention is focussed on collagen phagocytosis and degradation by fibroblasts which are currently considered to represent the basis of connective tissue remodelling and turnover.

Ameloblasts↗
PubMed1979

Oral histology and embryology: an integrated educational program.

Since 1976 dental students in The University of Western Australia have undertaken a revised course in oral histology and embryology taught within the framework of an oral biology program. The new course includes clinic sessions, which are presented prior to scheduled lecture and laboratory instruction on a particular tissue, and are intended to familiarize students with the clinical appearance of that tissue. Participating staff include members from the divisions of oral biology, oral pathology, periodontics, pedodontics, and preventive dentistry, Examination of histologic slides during laboratory sessions is supplemented by use of dental radiographs in order to achieve a close correlation between histologic structure and radiographic appearance. The use of the dental clinic environment to teach basic and applied microanatomy, and inclusion of clinical data such as radiographs, has strengthened the link between basic biological science and clinical dentistry.

Curriculum↗