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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Evaluation of a Colorimetric Assay as a Screening Test for Peridontal Disease

Landzberg, Michael 15 February 2010 (has links)
Background: Periodontal diagnosis relies on intraoral observable clinical factors including bleeding, probing depths, attachment loss, bone loss, and amount of plaque and calculus. Objective: To correlate neutrophil quantity and a colorimetric assay from an oral rinse with level of periodontal disease. To use this assay as a screening test for periodontal disease. Methods: Periodontal examinations of patients with healthy periodontium and periodontal disease were performed (n=125). Two concurrent saline rinses, 20 seconds each, were collected. Neutrophils were counted in each rinse. ABTS, a colour changing redox reagent, was added. The colour change was documented. Descriptive statistics, Spearman’s correlation, PPV, NPV, sensitivity and specificity were calculated. Results: Statistically significant correlation was found between neutrophils and colour change (rs=0.80, p<0.001); PPV and NPV for bleeding were 0.74 and 0.73, respectively. Conclusions: There is a correlation between neutrophils, colour change, and periodontal disease. The colorimetric assay can be used as a screening test for periodontal inflammation.
2

Evaluation of a Colorimetric Assay as a Screening Test for Peridontal Disease

Landzberg, Michael 15 February 2010 (has links)
Background: Periodontal diagnosis relies on intraoral observable clinical factors including bleeding, probing depths, attachment loss, bone loss, and amount of plaque and calculus. Objective: To correlate neutrophil quantity and a colorimetric assay from an oral rinse with level of periodontal disease. To use this assay as a screening test for periodontal disease. Methods: Periodontal examinations of patients with healthy periodontium and periodontal disease were performed (n=125). Two concurrent saline rinses, 20 seconds each, were collected. Neutrophils were counted in each rinse. ABTS, a colour changing redox reagent, was added. The colour change was documented. Descriptive statistics, Spearman’s correlation, PPV, NPV, sensitivity and specificity were calculated. Results: Statistically significant correlation was found between neutrophils and colour change (rs=0.80, p<0.001); PPV and NPV for bleeding were 0.74 and 0.73, respectively. Conclusions: There is a correlation between neutrophils, colour change, and periodontal disease. The colorimetric assay can be used as a screening test for periodontal inflammation.
3

Undergraduate Dental Students’ Experiences and Perceptions in the Provision of Dental Treatment to Persons with Disabilities

Perusini, Darsi 09 December 2013 (has links)
This study was undertaken to evaluate undergraduate dental students’ clinical experiences in a hospital-based dental clinic (D-clinic), and their influence on students’ comfort with providing dental care to persons with disabilities (PWDs). Dental students from a single class at the University of Toronto (n=94) were recruited to complete a survey: (I) close to the start, and (II) near the end of their rotations in D-clinic. Focus group data were used to write and revise survey questions. There was no significant difference in the students’ comfort with providing dental care to PWDs between phase-I and phase-II. Previous experience with PWDs was a positive predictor of comfort (P<0.001). Students in phase-II were less willing to provide dental care to individuals with developmental delay compared to students in phase-I (P=0.018). The majority of phase-II students (71%) valued D-clinic; 55% desired additional clinical experience to increase their comfort with providing dental care to PWDs.
4

Undergraduate Dental Students’ Experiences and Perceptions in the Provision of Dental Treatment to Persons with Disabilities

Perusini, Darsi 09 December 2013 (has links)
This study was undertaken to evaluate undergraduate dental students’ clinical experiences in a hospital-based dental clinic (D-clinic), and their influence on students’ comfort with providing dental care to persons with disabilities (PWDs). Dental students from a single class at the University of Toronto (n=94) were recruited to complete a survey: (I) close to the start, and (II) near the end of their rotations in D-clinic. Focus group data were used to write and revise survey questions. There was no significant difference in the students’ comfort with providing dental care to PWDs between phase-I and phase-II. Previous experience with PWDs was a positive predictor of comfort (P<0.001). Students in phase-II were less willing to provide dental care to individuals with developmental delay compared to students in phase-I (P=0.018). The majority of phase-II students (71%) valued D-clinic; 55% desired additional clinical experience to increase their comfort with providing dental care to PWDs.
5

Collagen Glycation Promotes Myofibroblast Differentiation

Yeung, Amy 07 April 2010 (has links)
The incidence of cardiomyopathy and cardiac fibrosis is markedly increased in patients with diabetes mellitus. As cardiac fibrosis is mediated by myofibroblasts, we investigated the effect of diabetes-associated collagen glycation on the conversion of cardiac fibroblasts to myofibroblasts. Collagen glycation was modeled by the glucose metabolite, methylglyoxal (MGO). Cells cultured on MGO-treated collagen exhibited increased activity of the α-smooth muscle actin (SMA) promoter, elevated levels of collagen I, α-SMA mRNA, and enhanced protein expression of α-SMA, ED-A fibronectin and cadherins. Increased expression of α-SMA was dependent on β1 integrins and on TGF-β. In collagen gel assays, MGO-collagen promoted faster contraction and cell migration was increased by MGO-collagen. In shear-force detachment assays, cells on MGO-collagen were less adherent, and β1 integrin activation and focal adhesion formation were inhibited. We conclude that collagen glycation augments the formation and migration of myofibroblasts, critical processes in the development of cardiac fibrosis in diabetes.
6

Collagen Glycation Promotes Myofibroblast Differentiation

Yeung, Amy 07 April 2010 (has links)
The incidence of cardiomyopathy and cardiac fibrosis is markedly increased in patients with diabetes mellitus. As cardiac fibrosis is mediated by myofibroblasts, we investigated the effect of diabetes-associated collagen glycation on the conversion of cardiac fibroblasts to myofibroblasts. Collagen glycation was modeled by the glucose metabolite, methylglyoxal (MGO). Cells cultured on MGO-treated collagen exhibited increased activity of the α-smooth muscle actin (SMA) promoter, elevated levels of collagen I, α-SMA mRNA, and enhanced protein expression of α-SMA, ED-A fibronectin and cadherins. Increased expression of α-SMA was dependent on β1 integrins and on TGF-β. In collagen gel assays, MGO-collagen promoted faster contraction and cell migration was increased by MGO-collagen. In shear-force detachment assays, cells on MGO-collagen were less adherent, and β1 integrin activation and focal adhesion formation were inhibited. We conclude that collagen glycation augments the formation and migration of myofibroblasts, critical processes in the development of cardiac fibrosis in diabetes.
7

Clinical Trials and Treatment Outcomes of Edentulous PatientsTreated with Implant-supported Prosthesis

Al-Fadda, Sara 23 September 2009 (has links)
Since their introduction, the use of endosseous implant for replacements of missing teeth has increased dramatically. To date, however, there is no evidence-based answer to the important clinical question: What implant-supported prosthesis designs provide the best outcomes? Cochrane systematic reviews have been used to critically assess scientific literature, to answer a wide array of questions. This approach was used to focus on implant-related treatment outcomes, including patient-based outcomes. Data showed that in most cases clinical and patient-mediated outcomes did not differ significantly from one another regardless of the prosthesis used. However, long-term prognosis of implant-supported overdentures using magnet attachments may produce inferior outcomes when compared to other attachments. In this dissertation it was shown that long-term results following immediate loading of endosseous implants with overdentures were successful based on biological and clinical parameters, cost to patient, and patient-based outcomes. Moreover, it was noted that well-designed clinical trials evaluating efficacy of immediate loading with fixed prostheses are uncommon. Furthermore, a parallel randomized controlled clinical trial focusing on this issue was carried out. In this trial, the author investigated the effects of immediate and delayed loading of implants with mandibular fixed prostheses. The implant-related outcomes underscore that even when implants are loaded during the healing period (i.e. immediate loading), successful osseointegration can be achieved and maintained. Patients’ satisfaction and oral health-related quality of life indicated that the two loading schemes addressed patient’s need equally.
8

Face Motor Cortex Neuroplasticity Associated with Alterations in the Oral Environment of the Adult Rat

Avivi-Arber, Limor 05 March 2010 (has links)
Neuroplastic changes in motor representations within the primary motor cortex (M1) have been described after peripheral manipulations and implicated in motor learning and adaptation processes. It is unclear whether dental manipulations, which may result in altered oral sensorimotor functions, are associated with analogous changes within face-M1. This project applied intracortical microstimulation (ICMS) and recordings of evoked muscle electromyographic (EMG) activity to test if changes occur in the ICMS-defined motor representations of tongue-protrusion (genioglossus, GG) and jaw-opening (anterior-digastric, AD) muscles within face-M1 and adjacent face primary somatosensory cortex (face-S1) following trimming or extraction of the rat’s right mandibular incisor, or a change in diet consistency. ICMS mapping was carried out in anaesthetised adult male rats. Consistent with previous findings, AD and GG had extensive motor representations showing considerable overlap in naïve and sham control rats. AD and GG motor representations were also found within face-S1. Left and right AD (LAD, RAD) had significantly larger representations with shorter onset latency of ICMS-evoked EMG responses within contralateral face-M1. A change in diet consistency for 2-3 weeks was not associated with significant changes in AD and GG motor representations within face-M1. Compared to control rats, iii incisor trimming out of occlusion for a period of 1 week resulted, 1 day later, in a significantly longer GG onset latency in ipsilateral than in contralateral face-M1; 1 week later, despite a regain of normal occlusion, GG and GG/AD overlapping representations were significantly larger and the centre of gravity (at AP 4.0) was significantly deeper in contralateral than in ipsilateral face-M1. Incisor extraction was associated, 1 week later, with significantly larger RAD and RAD/GG overlapping representations and a lateral shift of LAD and RAD centre of gravity. Extraction also induced significant changes in AD and GG motor representations within the contralateral face-S1. These novel findings indicate that face-M1 can undergo neuroplastic changes in association with intraoral manipulations and also suggest similar neuroplastic capabilities for face-S1 motor outputs. These findings contribute to our understanding of the role of face-M1 and face-S1 in sensorimotor adaptations to an altered oral state and provide the basis for several future studies.
9

Adolescent Compliance with Oral Hygiene Instructions during Fixed Orthodontic Treatment: A Pilot Study

Al-Jewair, Thikriat 30 July 2009 (has links)
Objectives: To determine compliance with oral hygiene instructions (OHI) of adolescents receiving two-arch fixed orthodontic treatment in a graduate orthodontic clinic and to identify predictive factors. Methods: Forty-one patients in a longitudinal pilot study were provided standardized OHI and assessed at baseline: before bonding (T1); 30 days after (T2), and 150 days after bonding (T3). Oral hygiene was measured using plaque and gingival indices. Compliance predictors were identified from questionnaires and patient records. Results: Good compliers increased from 10 at T1 to 29 at T3. Univariate analyses found perceived severity of malocclusion, school performance and parental marital status to be significant predictors. Multiple logistic regression identified having married parents and good school performance as significant predictors. Conclusions: In the sample studied, after initially worsening, compliance with OHI improved at five months after bonding. Adolescents with married parents and those reporting good academic performance in school were more likely to comply.
10

A Novel Technique for Class II Composite Restorations with Self-adhesive Resin Cements

Al-Saleh, Mohammed 14 December 2009 (has links)
Purpose: To determine microleakage and microtensile bond strength (µTBS) of composite restorations bonded with self-adhesive resin-cements. Methods: Six groups of molars were assigned to cements: RelyX-Unicem, Breeze, Monocem, PanaviaF-2.0, Filtek-LS, and Scotch-Bond-Multipurpose (adhesive). For microleakage, Class II preparations were made. Cements were applied onto all cavity walls. Preparations were restored, specimens themocycled and then immersed in red dye. Dye penetration was assessed according to 5-point scale. For µTBS test, 6 mm composite buildups were made over tooth surfaces. Rectangular rods were cut and subjected to tensile force. Mean µTBS and SDs were calculated. Results: RelyX-Unicem and Breeze showed low microleakage, however, they had lower µTBS values. Filtek-LS showed the least microleakage and the highest µTBS with dentin. Conclusion: RelyX-Unicem, Breeze and Filtek-LS will improve marginal seal when used in subgingival Class II composite restorations.

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