Melbourne Dental School - Theses
Permanent URI for this collection
Search Results
1 - 10 of 14
-
ItemA study of endodontically-related bacteria(University of Melbourne, 2008)
-
ItemInsertion sequence ISPg4 as a genetic virulence marker for porphyromonsa gingivalis in chronic periodontitis patients(University of Melbourne, 2006)
-
ItemInsertion sequence ISPg4 as a genetic virulence marker for porphyromonsa gingivalis in chronic periodontitis patients(University of Melbourne, 2006)
-
Item
-
Item
-
ItemEffectiveness and efficiency: systematic reflections on single- and multiple-visit root canal treatment( 2008)Single-visit root canal treatment was first documented in 1887. The controversy and debate within the dental community has been ongoing for over a century without resolution. The concept of evidence-based health practice has provided a structure on which the clinically-relevant questions in this debate can be dealt with systematically. When clinicians are faced with choices of which treatment regimen should be offered to patients, the central issues that should be considered are effectiveness, complications, patient/operator preference/satisfaction, and cost. Systematic review and meta-analysis techniques were used to reach definitive conclusions where high quality primary studies are available. The issue of satisfaction was studied using a quality of life concept, while the issue of cost was addressed by an economic evaluation (cost-minimization analysis). Treatment effectiveness and complications of single- and multiple-visit approach were similar. Patients overwhelmingly preferred single- over multiple-visit treatment with high satisfaction scores for both regimens. Australian endodontists were reluctant to embrace single-visit root canal treatment. Single-visit root canal treatment costs society less than multiple-visit treatment. On balance single-visit treatment offers substantial advantages with no identified adverse effects.
-
ItemThe diffusion of innovation in dentistry: factors associated with the adoption of rotary nickel-titanium endodontic instruments( 2004-01)The aim of this research was to investigate possible reasons for the adoption or non-adoption of new technology in dentistry, using rotary nickel-titanium (NiTi) technology as a model.This thesis first investigated the proportions of Australian dentists and endodontists who were using rotary NiTi instruments and their experiences with them. A questionnaire survey was conducted that explored general and specific issues concerning rotary NiTi instruments and techniques. An assessment of response rate and non-response bias was made by analysing responses to a question requiring a simple yes/no answer. Secondly, intraoperative defects, specifically fracture, of rotary NiTi instruments were assessed by collecting and examining over 7,000 rotary NiTi instruments used in patients by 14 endodontists from four countries and subsequently discarded. Thirdly, an assessment was made of whether rotary NiTi instruments can be predictably cleaned in the busy private practice setting.Analysis of the response rate and non-response bias in the questionnaire survey indicated the existence of differences between early and late responders despite no apparent demographic differences. Respondents to the questionnaire indicated many different reasons for adoption or non-adoption of the new technology, which could be interpreted as demonstrating behavioural differencesbetween adopters and non-adopters. Analysis of the discarded instruments indicated that the differences in technical ability between the endodontists was a more important clinical consideration in defect and fracture rates of rotary NiTi instruments than the perceived fragility of the instruments themselves. Also, a simple and effective protocol was developed for the predictable cleaning of rotary NiTi instruments. Therefore, overall, the results of the three parts of this thesis – the questionnaire survey, the instrument defects and the instrument cleaning – indicated the existence of personality and behavioural factors
-
ItemFactors affecting fracture susceptibility of tooth root: a laboratory and finite element analysis (FEA) study( 2004-11)From a fracture mechanics viewpoint, structural defects, cracks or canal irregularities are likely to play a major role in fracture susceptibility of the roots, because stresses can be exponentially amplified at these sites. By incorporating defects into a smooth round canal using rotary NiTi, theoretically the roots could be strengthened. The aims of the study were to determine whether rotary NiTi canal preparation strengthens roots, and whether the fracture pattern can be predicted by finite element analysis (FEA) models. 25 teeth were prepared using hand file and another 25 using rotary NiTi. After obturation, all teeth were subject to loading until fracture; load and patterns were recorded. Four FEA models were created from fractured roots. No significant difference of fracture load between the two techniques was found. Mesio-distal fracture occurred more often in the rotary NiTi group. Stress patterns in three of the four FEA models correlated well with the observed fracture patterns. The aim of the subsequent study was to determine the extent to which canal size, radius of curvature and proximal root concavity influence fracture susceptibility and pattern. A standardized cross-section of the mid-root region of a mandibular incisor was created by averaging the dimensions of ten extracted teeth, and the basic FEA model was created. By varying canal diameter, shape and proximal concavity, these factors could be examined for roles in fracture susceptibility and pattern. The factors all interact in influencing fracture susceptibility and pattern, with dentine thickness not the only determining factor. The removal of dentine does not always result in increased fracture susceptibility.
-
ItemInvestigations into the mechanical properties and curing characteristics of dental glass-ionomer cements( 2005-11)Conventional glass ionomer cements (GICs), which continue to gain acceptance as superbly biocompatible dental materials, were first released in the early 1970s as a result of research into combining the advantages of silicate cements and polyalkenate cements. The chemistry of GICs is based upon the aqueous reaction between an ion-leachable fluoride glass and polyacid which yields the final cross-linked insoluble ionomer (ionic polymer). The significant advantages of GICs include direct adhesion to tooth structures, fluoride release, minimal dimensional change on curing, significant ease of use and superb biocompatibility, to the extent that affected proximal tooth structures may be retained, remineralised , and strengthened against further caries. GICs have, however, been unfavourably compared with other restorative materials in their mechanical properties and setting characteristics, in particular their relative weakness, the time limitations for the acid-base reaction to proceed to acceptable maturity, and the susceptibility of the immature cement to water sorption or desiccation.
-
ItemAn analysis of the effectiveness of a continuing professional development (CPD) program for dentists in Victoria( 2009)Periodontitis is a common condition resulting in destruction of periodontal tissues and eventually tooth loss. Every patient requires appropriate diagnosis and treatment by their dental practitioner. Periodontics has undergone many innovations in recent years. It is the onus of the treating dentist to keep abreast of developments in order to provide quality care to their patients. Unfortunately there is literature indicating that some Victorian dentists may not be following appropriate clinical practice in the identification and management of the periodontal needs of their patients. To address this, the School of Dental Science, the University of Melbourne, began conducting a Continuing Professional Development course titled ‘Periodontics via Distance Learning’. The course was composed of a mixture of hands on, distance learning and didactic components. This study assessed changes in clinical practice of course participants via the use of a delayed impact on practice questionnaire. All those who participated in the course in 2005 and 2006 were sampled. A response rate of 85% was recorded. Overall, an increase in practitioner confidence in periodontal diagnosis and periodontal treatment was reported and with many respondents indicated changes in their clinical practice had occurred. However, the reported changes recorded were not universal to all participants. Further research is required to determine how best to structure a dental CPD course.