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An evaluation of the colours of base metal alloy oxide layers, and its effects on the shade of base metal alloy metal-ceramic restorationsSomers, Grant Brandon January 1997 (has links)
Dissertation submitted in compliance with the requirements for the Master's Degree in Technology: Dental Technology, Technikon Natal, 1997. / Globally, difficulties are being experienced by the dental world to match manufactured prosthetic restorations with natural tooth colour. The primary objective of this study was therefore to evaluate the colour of five different metalceramic base metal alloy oxide layers, and the effects of each oxide layer on the shade of the porcelain applied to its surface. The increase in the cost of gold alloys in the dental industry has influenced manufacturers to provide alloys which are cost effective and have adequate mechanical properties for the manufacture of metal ceramic restorations. Five base metal alloys used in the fabrication of metal-ceramic restorations were selected. The selection of the base metal alloys was based on popularity in the industry, availability and cost. The following five base metal alloys were selected for the investigation: Wiron 99 (nickel-chrome) Ceradium V (nickel-chrome-beryllium) Remanium CD (nickel-chrome) \x95 Wirobond (cobalt-chrome) Heranium (nickel-chrome) Bond-on-4 (low noble content alloy {control group; which was gilded}) II Thirty specimens for each alloy group (180 in all) were cast, using the lost wax technique. Three ceramic layers (notably the opaque, dentine and a glaze layer) were applied to the 20mm in diameter surface of each specimen. .\xB7t Finally both sample groups were tested against a custom shade guide the colour being compared specifically with the Vita A 1 shade. The reason for the inclusion of the shade guide was that, clinically, most shade selections are made by comparing the patient's tooth shade with a manufactured shade guide. A wide selection of shades are available to the ceramist. A certain school of thought that recommends that the metal surfaces of semi-precious metals be gilded with a gold gilding paste before the application of ceramics. in order to block out the dark oxide colour and enhance the colour of the ceramic to a more aesthetic and warmer colour. Therefore, prior to the opaque firing of the control group (Bond-on-4), a gilding layer of Spectra Seal Paste was applied to the surface of each specimen. Following each application of ceramic, the appropriate firing cycles were used to fire the ceramic. The following factors affected the selection of the shade of ceramic used in this study: the shade which is most influenced by the dark oxide layer the more popular shades of ceramic ( the A class of shades). It was established, through a review of the literature (Crispen, 1991), that the most objective form of testing colour at the time of the study, was the use of a reflectance spectrophotometer. This form of testing had been proved to be cost effective and was consequently used in this investigation. III Thesurve / M
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The performance of base metal ceramic alloy restorations with reference to variances in thickness in metal and porcelain in order to establish optimal thickness ratios to maxize strength and aesthetic characteristicsLe Roux, Andre Rayne January 2000 (has links)
Dissertation submitted in compliance with the requirements for the Master's Degree in Technology: Dental Technology, Technikon Natal, 2000. / The greatest problem in maximizing strength and aesthetic characteristics of metal ceramic restorations arises when there is a lack of available space to allow sufficient thickness of metal alloy and porcelain. This generally results in the metal alloy being reduced to its minimum to allow adequate porcelain thickness. The minimum thickness to which noble metal alloys can safely be reduced, is generally accepted to be 0.3 mm due to previous clinical time-dependent trial and error. Agreement regarding the minimum thickness to which base metal alloys can safely be reduced is still under dispute possibly because base metal alloys have not had the same duration of clinical exposure. The objectives of the present study were: 1. To determine the influence thickness variations of the base metal alloy would have on strength characteristics of metal ceramic restorations and thereby establishing the minimum thickness to which base metal alloys can safely be reduced. 2. To determine the influence thickness variations of porcelain would have on strength and aesthetic characteristics of metal ceramic restorations and thereby establish the minimum thickness to which the porcelain thickness can safely be reduced. 3. To determine which base metal alloy to porcelain thickness ratios would be most suited in order to maximize strength and aesthetic characteristics in metal ceramic restorations where the amounts of available space for the alloy and porcelain are varied. For objective (1) Tensile strength tests to determine and compare the ability of various alloy thickness to resist porcelain fracture were performed in Newtons. For objective (2) Tensile tests to determine and compare the ability of various porcelain thickness to resist porcelain fracture were performed in Newtons. / M
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An in vitro investigation of the effects of surface corrosion on the metal element content and tensile strength of orthodontic silver brazed stainless steel joints arising from varying exposure periods in Fusayama's artificial salivaVahed, Anisa January 2004 (has links)
Thesis (M.Tech.: Dental Technology)-Dept. of Dental Technology, Durban Institute of Technology, 2004
xvi, 173 leaves : ill. ; 30 cm / Globally in the field of Dental Technology, brazing continues to be the prevailing joining technique for removable orthodontic appliances. However, the strength of the brazed joint is a growing concern to dental technicians since the commonly employed silver solder brazing material undergoes changes in brazed joint composition (microstructure) thereby enhancing corrosion susceptibility. This ultimately influences the success of orthodontic appliances intra-orally.
The objective of this in vitro investigation was therefore to determine the effects of corrosion on the composition and tensile strength of orthodontic silver brazed stainless steel joints after varying exposure periods in Fusayama’s artificial saliva.
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Perceptions of Zambian dentists and dental technicians in respect of dental technical servicesMukena, Martha Mutinta January 2010 (has links)
Thesis submitted in full compliance with the requirements for a Master's Degree in Technology: Dental Technology, Durban University of Technology, 2010. / This study is an evaluation of the perceptions of Zambian dental technicians
and dentists of the dental technological services offered in Zambia. Zambia is
a small nation (land size of 752,614km²) with a population of approximately
11,000,000. Patients needing oral restorative treatment have two options
available to them; they seek treatment in state hospitals or through private
practices. Access to prosthetic treatment is difficult due to the difficulties
associated with obtaining treatment from the state as well as there being very
few privately owned dental laboratories. Dental technology in Zambia dates
back to 1964 and since its inception there has been no evaluation as to
whether the services offered are adequate and satisfactory.
The aim of this study was to;
Provide insights into the understanding of dentists and technicians
regarding dental technical services.
Provide insights into available dental technical services with the aim of
assisting in developing future guidelines for provision of such services
in Zambia.
Identify national oral health objectives and make suggestions for the
improvement and development of the services in Zambia.
This aims of the research are relevant as the research was conducted at a
time when the nation is undergoing a general introspection of service delivery.
Data was collected through the medium of semi-structured personal
interviews with registered and practicing dentists and technicians in the main
cities of Zambia that include Lusaka, Ndola and Kitwe. Their views were
transcribed and coded according to significant themes that emerged for data
analysis.
ii
The results indicate that there is reason to be concerned about the general
quality of service delivery. In addition, the study showed that the working
relationships between technicians and dentists require improvement.
Moreover, the study established that Zambia has a critical shortage of skilled
technicians and particularly ceramic technicians and ceramic dental
laboratories. The data also revealed concerns that little attention by
government policymakers is being afforded to dental technical services whilst
attention is paid rather to clinical dental services. As a result, state owned
laboratories suffer from a lack of adequate and functioning equipment as well
as a lack of quality dental materials. Finally, the study showed that Zambia
has no clear direct oral health policies that govern the dental technical
services.
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Perceptions of the professionalization of dental technologySkea, Denise Angela January 2010 (has links)
Submitted in fulfilment of the requirements of the Degree of Master of Technology: Dental Technology, Durban University of Technology, 2010. / This study investigates the perceptions of dentists, dental technicians and dental
patients with regard to the professionalization of dental technology as it is currently
constituted in South Africa. The origin of dental technology worldwide lies in a trade
and has historically been performed by craftsmen under the instruction of dentists.
In South Africa during the early 1900s dental technology was practised in much the
same way but the need for formalization of this field had been recognised. By 1945
dental technology was regulated by the Dental Mechanicians Board, which enabled
only registered technicians to practise dental technology within South Africa. This
field continues to be practised similarly at present. In order to establish the
professional development of dental technology it is necessary to consider this field
within a framework of desired professional attributes. This framework is provided by
Greenwood (1957), who defines a profession by the following five attributes:
systematic theory, professional authority, community sanction, ethical codes and a
professional culture. Owing to the varied implementation and regulation of dental
technology worldwide, little research into the professionalization of this field has
been conducted to date.
For the purpose of this study, dentists, dental technicians and dental patients in
KwaZulu-Natal were interviewed in semi-structured interviews. The main themes
emerging from this study were identified and considered with reference to the
framework within which this study has been positioned.
This study concludes that dental technology, as it is currently constituted in South
Africa is perceived to be a profession by dentists, dental technicians and dental
patients. .The term profession, however, is poorly understood by all three sample
groups. Despite being considered a profession, dental technology is not considered
to encompass all the attributes of a profession. Dental technology is therefore
identified as a developing profession that positions this field somewhere along the
professionalization continuum between a profession and a business. / Post Graduate Dept., Durban University of Technology.
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An in vitro investigation of the effects of surface corrosion on the metal element content and tensile strength of orthodontic silver brazed stainless steel joints arising from varying exposure periods in Fusayama's artificial salivaVahed, Anisa January 2004 (has links)
Thesis (M.Tech.: Dental Technology)-Dept. of Dental Technology, Durban Institute of Technology, 2004
xvi, 173 leaves : ill. ; 30 cm / Globally in the field of Dental Technology, brazing continues to be the prevailing joining technique for removable orthodontic appliances. However, the strength of the brazed joint is a growing concern to dental technicians since the commonly employed silver solder brazing material undergoes changes in brazed joint composition (microstructure) thereby enhancing corrosion susceptibility. This ultimately influences the success of orthodontic appliances intra-orally.
The objective of this in vitro investigation was therefore to determine the effects of corrosion on the composition and tensile strength of orthodontic silver brazed stainless steel joints after varying exposure periods in Fusayama’s artificial saliva.
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The accuracy of two die systems to replicate a master tooth a thesis submitted in partial fulfillment ... in denture prosthodontics ... /Czerniawski, Benjamin J. January 1986 (has links)
Thesis (M.S.)--University of Michigan, 1986.
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The accuracy of two die systems to replicate a master tooth a thesis submitted in partial fulfillment ... in denture prosthodontics ... /Czerniawski, Benjamin J. January 1986 (has links)
Thesis (M.S.)--University of Michigan, 1986.
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Perceptions on the addition of clinical practice to the dental technology curriculumMqadi, Nonhlanhla Precious January 2009 (has links)
Submitted in full compliance with the requirements for a Master’s degree in Technology: Dental Technology at the Durban University of Technology, 2009. / The Dental Technology profession in South Africa is currently undergoing a possible role transformation. In the past, Dental Technicians were restricted to laboratory work only and were not permitted to have direct contact with patients. Due to a demand for oral care, and a gap that is perceived to exist in service delivery, Clinical Dental Technology has emerged as a possible new profession in South Africa. The 1997 amendment to the Dental Technicians Act allows Dental Technicians to broaden their scope of practice through further education into the clinical aspects of the profession.
South Africa is one of few countries that have an enabling legislation in terms of the recognition of Clinical Dental Technology. However, there is to date no training programme or curriculum for people who would like to practise as Clinical Dental Technicians. The three institutions in South Africa that provide training for Dental Technicians do not provide training to those technicians who would like to pursue a clinical career path.
Internationally, Dentists have argued that Dental Technicians have insufficient clinical capabilities. They feel that technicians do not have sufficient knowledge and experience in dealing directly with patients, and consequently have identified a need for further training of Dental Technicians before they are recognised as Clinical Dental Technicians.
The aim of this study was to evaluate educational institutions’ readiness in terms of the role transformation of Dental Technicians and to establish perceptions about the introduction of this new profession by Dentists, Dental Technicians and Dental Technology lecturers. The views of these three stakeholders have implications not only in terms of the development of a new curriculum, but were also found to raise serious concerns about the implementation of this profession in South Africa.
Data was collected by means of questionnaires and personal interviews with Dentists, Dental Technicians and Dental Technology lecturers in South Africa. The responses were transcribed and then coded according to pertinent themes for interpretation purposes.
The data revealed major differences in the perceptions of the proposed profession by the three sectors. This has important implications for the likely success of Clinical Dental Technology, given the need for these sectors to work together as members of the dental team. The data also reveals concerns about the type of training that would need to be incorporated into the curriculum and who would be able to provide such training. By using an overview of curriculum theory, this study also raises concerns that clinical aspects might be infused into the curriculum as simply the acquisition of additional technical skills, rather than as a significant shift in professional identity to incorporate patient care.
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Perceptions on the addition of clinical practice to the dental technology curriculumMqadi, Nonhlanhla Precious January 2009 (has links)
Submitted in full compliance with the requirements for a Master’s degree in Technology: Dental Technology at the Durban University of Technology, 2009. / The Dental Technology profession in South Africa is currently undergoing a possible role transformation. In the past, Dental Technicians were restricted to laboratory work only and were not permitted to have direct contact with patients. Due to a demand for oral care, and a gap that is perceived to exist in service delivery, Clinical Dental Technology has emerged as a possible new profession in South Africa. The 1997 amendment to the Dental Technicians Act allows Dental Technicians to broaden their scope of practice through further education into the clinical aspects of the profession.
South Africa is one of few countries that have an enabling legislation in terms of the recognition of Clinical Dental Technology. However, there is to date no training programme or curriculum for people who would like to practise as Clinical Dental Technicians. The three institutions in South Africa that provide training for Dental Technicians do not provide training to those technicians who would like to pursue a clinical career path.
Internationally, Dentists have argued that Dental Technicians have insufficient clinical capabilities. They feel that technicians do not have sufficient knowledge and experience in dealing directly with patients, and consequently have identified a need for further training of Dental Technicians before they are recognised as Clinical Dental Technicians.
The aim of this study was to evaluate educational institutions’ readiness in terms of the role transformation of Dental Technicians and to establish perceptions about the introduction of this new profession by Dentists, Dental Technicians and Dental Technology lecturers. The views of these three stakeholders have implications not only in terms of the development of a new curriculum, but were also found to raise serious concerns about the implementation of this profession in South Africa.
Data was collected by means of questionnaires and personal interviews with Dentists, Dental Technicians and Dental Technology lecturers in South Africa. The responses were transcribed and then coded according to pertinent themes for interpretation purposes.
The data revealed major differences in the perceptions of the proposed profession by the three sectors. This has important implications for the likely success of Clinical Dental Technology, given the need for these sectors to work together as members of the dental team. The data also reveals concerns about the type of training that would need to be incorporated into the curriculum and who would be able to provide such training. By using an overview of curriculum theory, this study also raises concerns that clinical aspects might be infused into the curriculum as simply the acquisition of additional technical skills, rather than as a significant shift in professional identity to incorporate patient care.
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