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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.
101

Evaluation of the Toronto Palatal Lift Prosthesis for Patients with Hypernasal Resonance Disorders

Ayliffe, Brett William 11 July 2013 (has links)
Statement of the problem. Hypernasality resulting from velopharyngeal insufficiency or incompetency is a resonance disorder that has negative consequences for speech production and intelligibility of afflicted individuals. Purpose. The purpose of this prospective study is to ascertain if a palatal lift prosthesis with a generic silicon velar lamina, termed the Toronto Palatal Lift Prosthesis (TPLP), can assist velopharyngeal valve function to reduce hypernasality in patients. Methods. A prospective study of six patients treated with the TPLP was compared by the outcome measures of nasalance scores, perceptual evaluations, and patient satisfaction to those obtained using a contemporary acrylic palatal lift prosthesis. Results. The six patients had varying degrees of reduction in hypernasality and acceptance of the TPLP. Conclusion. On the basis of this preliminary study on the TPLP it is possible to fabricate a palatal lift prosthesis with a generic silicon velar lamina that reduces hypernasality in select patients.
102

Evaluation of the Toronto Palatal Lift Prosthesis for Patients with Hypernasal Resonance Disorders

Ayliffe, Brett William 11 July 2013 (has links)
Statement of the problem. Hypernasality resulting from velopharyngeal insufficiency or incompetency is a resonance disorder that has negative consequences for speech production and intelligibility of afflicted individuals. Purpose. The purpose of this prospective study is to ascertain if a palatal lift prosthesis with a generic silicon velar lamina, termed the Toronto Palatal Lift Prosthesis (TPLP), can assist velopharyngeal valve function to reduce hypernasality in patients. Methods. A prospective study of six patients treated with the TPLP was compared by the outcome measures of nasalance scores, perceptual evaluations, and patient satisfaction to those obtained using a contemporary acrylic palatal lift prosthesis. Results. The six patients had varying degrees of reduction in hypernasality and acceptance of the TPLP. Conclusion. On the basis of this preliminary study on the TPLP it is possible to fabricate a palatal lift prosthesis with a generic silicon velar lamina that reduces hypernasality in select patients.
103

Resistência de união e limite de fadiga de nichos confeccionados em resina composta e cimentos à base de ionômero de vidro /

Lopes, José Fernando Scarelli. January 2003 (has links)
Orientador: Carlos Eduardo Vergani / Banca: Eunice Teresinha Giampaolo / Banca: João Henrique Nogueira Pinto / Resumo: O objetivo desta investigação foi determinar a resistência de união e limite de fadiga de nichos confeccionados em resina composta e ionômeros de vidro. Setenta e cinco corpos-de-prova (incisivos mandibulares humanos hígidos) com etiquetas adesivas com perfurações de 3,5mm de diâmetro foram adaptadas sobre a superfície lingual de cada dente. Esta delimitação tinha como objetivo padronizar a área da superfície de esmalte a ser condicionada e, posteriormente, mantida em contato com os materiais restauradores. Para realização dos nichos, matrizes foram realizadas para cada corpo-de-prova onde o material restaurador foi inserido. Os corpos-de-prova foram imersos em água destilada a 37ºC por um período de 30 dias. Para os ensaios de resistência à união, a máquina de testes mecânicos MTS modelo 810 foi calibrada utilizando uma velocidade de deslocamento de 0,5mm/min. Para os testes de limite de fadiga a máquina de testes foi calibrada para submeter cada corpo-de-prova a 10.000 ciclos constantes, com uma freqüência de 5 Hz, amplitude inicial de 0,5 mm e velocidade de rampa inicial de 100N/s. Os valores originais do experimento foram convertidos de N para MPa em função da área da base do nicho (circular) previamente calculada. Os corpos-de-prova após a fratura foram avaliados através de microscopia eletrônica de varredura com aumento de 500 vezes. A médias de resistência à união e limite de fadiga foram comparadas estatisticamente usando o teste de Análise de Variância a um Critério. Nos teste de cisalhamento, a resina composta Z-100 produziu maior valor de resistência de união (12,25 MPa) ao esmalte dentário que o ionômero de vidro convencional Fuji IX (7,21MPa). Não foram observadas diferenças entre os valores do material Fuji II LC (10,29MPa) e os demais materiais. Para todos os materiais, os corpos-de-prova testados por meio de ensaio dinâmico de ...(Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The aim of this study was to determine the bond strength and fatigue limit of rest seats prepared with composite resin and glass ionomer cements. The lingual aspect of seventy-five specimens (intact human mandibular incisors) was delimited by adhesive tags with 3.5-mm diameter perforations. This delimitation aimed at standardizing the area of enamel surface to be etched and later kept in contact with the restorative materials. For preparation of the rest seats, matrixes were obtained for each specimen on which the restorative material was placed. The specimens were immersed in distilled water at 37ºC for a period of 30 days. For the bond strength assays, the mechanical assay machine MTS model 810 was calibrated at a displacement speed of 0.5mm/min. For the fatigue limit tests, the assay machine was calibrated so as to submit each specimen to 10,000 constant cycles, at a 5-Hz frequency with an initial range of 0.5mm and initial sloping speed of 100N/s. The original values of the experiment were converted from N to MPa according to the previously calculated circular area of the base of the rest seat. After fracture, the specimens were evaluated by means of scanning electron microscopy with magnification of 500x. The means of bond strength and fatigue limits were statistically compared through the one-way variance analysis. For the shear resistance test, the composite resin Z-100 yielded a higher value of bond strength (12.25 MPa) to the dental enamel than the conventional glass ionomer cement Fuji IX (7.21MPa). No differences could be found between Fuji II LC (10.29MPa) and the further materials. For all materials, the specimens submitted to dynamic fatigue assay tests yielded lower mean values than those achieved through static shear assays. Regarding the fatigue limit values, all materials presented different behaviors, being that Fuji II LC obtained the higher mean value (6.4MPa), ...(Complete abstract, click electronic access below) / Mestre
104

Análise da viabilidade da aplicação da tecnologia CAD-CAM por prototipagem rápida na confecção de estrutura metálica da prótese parcial removível comparando-a ao método convencional / Analysis of the viability of the application of CAD-CAM technology of rapid prototyping in manufacturing removable partial dentures compared to the conventional method

Alvaro Luis Ichi 11 November 2010 (has links)
A tecnologia CAD-CAM vem sendo aplicada há mais de uma década para a confecção de trabalhos protéticos odontológicos e bucomaxilofaciais. A tecnologia de prototipagem rápida permite a construção de um modelo em tempo reduzido por meio do sistema CAD (computer-aided design) e CAM (computer-aided manufacturing), permitindo absoluta fidelidade ou discrepância desprezível. Assim, o objetivo deste trabalho será analisar a viabilidade da aplicação da tecnologia CAD-CAM por prototipagem rápida na confecção de estrutura metálica da prótese parcial removível, comparando-a ao método convencional. O projeto visa à obtenção de melhores benefícios funcionais e econômicos aos pacientes, trazendo à luz inovações tecnológicas, novos conceitos e melhores condições para o restabelecimento da saúde bucal. A metodologia empregada partiu da reprodução de um modelo padrão de uma arcada inferior parcialmente desdentada, classe III Mod-1 de Kennedy. Quatro pilares metálicos foram posicionados no local dos primeiros pré-molares e molares. Com o auxílio de um scanner digital 3D, obteve-se um modelo virtual da arcada, no qual foi modelado digitalmente o desenho da estrutura protética. Oito estruturas de PPR foram confeccionadas utilizando-se a tecnologia de prototipagem rápida e, posteriormente fundidas em liga de cobalto-cromo. Outras oito estruturas foram confeccionadas seguindo o protocolo para confecção de PPR de forma convencional. A análise comparativa foi realizada avaliando o peso perdido. A avaliação por peso está dividida em dois grupos. O primeiro, denominado Grupo AP (Ajuste e Polimento), possui quatro estruturas convencionais (Grupo AP-C) e quatro prototipadas (Grupo AP-P). O segundo, chamado Grupo A (Ajuste) realizado somente ajuste sem polimento, com quatro estruturas convencionais (Grupo A-C) e quatro prototipadas (Grupo A-P). Análise comparativa por peso mensurou a porcentagem de material perdido necessário para o adequado assentamento dos apoios das estruturas metálicas pela técnica convencional e por prototipagem em seus respectivos descansos. Os resultados mostraram que as estruturas foram passíveis de serem obtidas pela tecnologia proposta. A análise comparativa mostrou que o Grupo AP-P apresentou um desgaste médio de 0,9826g, correspondente a 13,5188% de seu peso inicial; o Grupo AP-C apresentou um desgaste médio de 0,7529g, correspondente a 12,4380% de seu peso inicial. A análise por meio de Teste t independente mostrou uma diferença estatisticamente significante com valor de p=0,0386, p<0,05. No Grupo A-P houve um desgaste médio de 0,1045g, correspondente a 1,4455% de seu peso inicial. No Grupo A-C houve um desgaste médio de 0,1473g, correspondente a 2,3188% de seu peso inicial. A análise por meio de Teste t independente mostrou uma diferença estatisticamente significante com valor de p=0,0038, p<0,01. Foi viável a aplicação da tecnologia CAD-CAM por prototipagem rápida na confecção de estrutura metálica da prótese parcial removível. / The CAD-CAM technology has been applied for more than a decade for the manufacturing of dental and maxillofacial prosthesis. The rapid prototyping technology allows for the construction of a model in reduced time by using the CAD (computer-aided design) and CAM (computer-aided manufacturing) systems, allowing absolute preciseness or negligible discrepancies. Thus, the purpose of this research is to analyze the viability of the application of the CAD-CAM technology of rapid prototyping in the manufacturing of removable partial dentures(RPD) compared to the conventional method. The purpose of this research was to obtain functional and financial benefits for the patient, demonstrate recent technological advances and concepts and improve the resources for the reestablishment of oral health. The methodology used to determine effectiveness of the CAD-CAM system started with the reproduction of a Kennedy Class III Modification 1 cast of an inferior partially edentulous dental arch,. Four metallic pins were positioned in place of the first premolars and molars. A 3D scanner was used to construct a virtual model of the arch on which the design of the prosthetic structure was digitally formed. Eight RPD frameworks were manufactured using the fast prototyping technology with subsequent casting with a cobalt-chromium alloy; eight others followed the standard RPD waxing/casting procedure. The analysis between procedures evaluated the weight lost when each of the respective frameworks were processing. The results were divided into two groups. The first group, named AP (Adjusted and Polished), had four standard (Group AP-C) and four prototyped (Group AP-P) frameworks. The second group, named A (Adjusted), also includes eight frameworks (four standard, Group A-C, and four prototyped, Group A-P) which were cast and adjustted but not polished. In the comparative analysis, the variation of the weight determined the percentage of the material lost needed for the adequate settling of the rests in their respective seat with the standard and prototyped methods. The data indicated that frameworks can be obtained with the proposed technology. The comparative analysis results showed an average wear of 0.9826g on Group AP-P, corresponding to 13.5188% of its initial weight. In the Group AP-C, average wear was 0.7529g, 12.4380% of its initial weight. With the independent t-test, a significant statistical difference of p=0.0386, p<0.05 was found. The average wear for Group A-P wasf 0,1045g, 1.4455% of its initial weight, while in Group A-C the value was 0.1473g, corresponding to 2.3188% of its initial weight. The independent t-test analysis for these cases shows a significant statistical difference of p=0.0038, p<0.01. The application of the CAD-CAM technology of fast prototyping is viable for the manufacturing of removable partial dentures.
105

Trvanlivost destiček ADMX při frézování materiálů skupiny S / Tool life of ADMX inserts for milling of the S-grade materials

Tejkl, Jakub January 2014 (has links)
This diploma thesis studies the machining of group S materials. In the theoretical part of this thesis these materials were divided into groups and subsequently analyzed. These materials were also analyzed in terms of their impaired machinability. In the practical part of this thesis experimental tests were conducted to determine tool life, tool wear and in the case of testing titanium alloy surface roughness too.
106

Vapor-liquid Equilibrium of Polymer Solutions During Thermal Decomposition of Rigid Foams

King, Nathan H. 15 July 2008 (has links) (PDF)
Removable Epoxy Foam (REF) and other rigid foams experience severe changes in structure and properties when exposed to high heat. As thermal energy breaks network bonds in the foam many species are formed, including large polymer-like network fragments and smaller solvent-like molecules. During this process a liquid phase may form. The vapor-liquid equilibrium (VLE) behavior of the polymer solutions formed during initial decomposition can be highly non-ideal. In this research VLE behavior of high-temperature polymer solutions was studied and a procedure was developed for predicting that behavior during decomposition of rigid foams. A high-temperature VLE facility was built and validated, and equilibrium pressures were measured at temperatures between 75 and 250ºC for six polymer/solvent systems: two polymers – polyethylene glycol and polystyrene – with each of three solvents – benzene, furan, and 4-isopropylphenol. Calculations from eighteen polymer solution models were compared with experimental results to determine which model best described the VLE behavior. These models included six existing activity coefficient models used alone, as well as in combinations with the Peng-Robinson equation of state (EOS) through the Wong-Sandler mixing rules. Because several of the models required values for polymer volumes, a comparison of the GCVOL and GCMCM group-contribution volume estimation methods was performed. GCMCM was found to give lower overall deviations from literature polymer volume data. The models involving an equation of state required EOS parameter values for the pure polymers. A new method for determining these parameters was proposed. Models using parameters from the new method gave better agreement with equilibrium pressure data than models using parameters from the recommended method in the literature. While agreement with equilibrium pressure data was similar for several models, some models predicted a liquid phase split under certain conditions. Data were not available to verify the presence of two liquid phases, but are needed to make an appropriate recommendation of the best model. If liquid phase splitting does not occur, it is recommended that the UNIFAC-ZM activity coefficient model be used alone. If phase splitting behavior is observed, it is recommended that the UNIFAC-FV activity coefficient model be used in combination with the Peng-Robinson EOS.
107

Polyoxymethylene as Material for Removable Partial Dentures—A Literature Review and Illustrating Case Report

Schierz, Oliver, Schmohl, Leonie, Hahnel, Sebastian, Rauch, Angelika 04 May 2023 (has links)
Compared to thermoplastic manufacturing techniques, computer-aided design (CAD) and computer-aided manufacturing (CAM) technologies make it easier to process modern restorative and prosthetic materials with improved material properties. In dentistry, tooth-colored alternatives to metal-based frameworks for application in removable dental prostheses (RDP) emerged. With regard to this aspect, the current article provides an overview of the specific material properties of polyoxymethylene (POM). Furthermore, it reviews scientific literature indexed in PubMed and Web of Science that focuses on RDPs fabricated from POM within the last 10 years. Finally, a prosthetic rehabilitation of a patient with a RDP fabricated from POM is illustrated and observations during a follow-up over 10 months are described. Scientific data and clinical observations indicate that polyoxymethylene is a promising material that bridges gaps in dental therapeutic options. While survival time may be limited due to wear, POM might be a favorable option for application in semi-permanent restorations.
108

Bindningsstyrka mellan protesbas och protestand beroende på framställningsteknik och åldring / Bond strength between Denture Base and Denture Tooth Depending on the Manufacturing Technique and Ageing

Cronberg, Blanka, Rasho, Lina January 2024 (has links)
Sammanfattning Syfte Studiens syfte var att utvärdera bindningsstyrkan mellan protesbas och protestand beroende på framställningsteknik, med 3D-printning eller fräsning, och efter åldring.Material och metodTotalt framställdes 40 provkroppar varav 20 tillverkades genom 3D-printning (P) med SprintRay EU (SprintRay GmbH, Iserlohn, Tyskland) och 20 genom fräsning (F) med Ivotion (Ivoclar Vivadent AG, Schaan, Liechtenstein). Hälften av de frästa (TF) och 3D-printade provkropparna (TP), det vill säga 10 av varje, utsattes för 5 000 termocykler i temperaturerna 5 och 55 °C (T) och förvarades i destillerat vatten i 48 timmar vid en temperatur på 37° C. Bindningsstyrkan mättes genom ett skjuvkrafttest enligt standardiserade metoder.Envägs-ANOVA och Tukey’s test användes för statistisk utvärdering av resultaten där signifikansnivån sattes till α=0,05. En frakturanalys utfördes för att bedöma frakturtyper. Resultat Resultaten visade att P hade en signifikant högre bindningsstyrka än F (p&lt;0,001). Skillnaden kvarstod även efter åldring. Det var ingen signifikant skillnad (p=0,626) i bindningsstyrkan mellan F och TF. TP uppvisade signifikant lägre bindningsstyrka jämfört med P (p=0,007).Alla F fick en adhesiv och kohesiv blandfraktur. P fick nio kohesiva och en adhesiv fraktur. TF fick sex adhesiva och fyra blandfrakturer. TP fick sju kohesiva och tre blandfrakturer. Slutsats 3D-printade material har en högre bindningsstyrka mellan protesbas och protestand jämfört med frästa. Åldring har en större negativ inverkan på bindningsstyrkan mellan protesbas och protestand om materialen är 3D-printade jämfört med om de är frästa. / Abstract Objective The aim of the study was to evaluate the bond strength between denture base and denture tooth depending on the manufacturing technique, fabricated through either 3D-printing or milling, and after ageing.Material and methods40 specimens were produced, 20 were produced through 3D-printing (P) using SprintRay EU (SprintRay GmbH, Iserlohn, Genmany) and 20 through milling (F) using Ivotion (Ivoclar Vivadent AG, Schaan, Liechtenstein). Half of the milled (TF) and printed specimens (TP), i.e., 10 of each group, underwent 5 000 cycles of thermocycling and were stored in distilled water for 48 hours at a controlled temperature of 37° C. Bond strength was evaluated using a shear bond strength test.One-way ANOVA and Tukey’s test were employed to assess the results with a significance level at α=0.05. Fracture analysis was conducted to evaluate the fracture type. Results The result showed that P had significantly higher bond strength compared to F (p &lt;0.001). The difference remained after the ageing process. The comparison between F and TF yielded non-significant results (p=0.626). P had significantly higher bond strength than TP (p=0.007).All F had mixed fractures of adhesive and cohesive. P had nine cohesive and one adhesive fracture. TF had six adhesive fractures and the remaining were mixed fractures. TP had seven cohesive fractures and three mixed fractures. Conclusion 3D-printed materials have higher bond strength between the denture base and denture tooth compared to milled materials. Ageing has a greater negative impact on the bond strength between the denture base and denture tooth of printed materials compared to milled materials.
109

Ispitivanje biokompatibilnosti i mehaničkih karakteristika polimera za bazu zubne proteze / The investigation of biocompatibility and mechanical properties of denture base resins

Potran Michal 05 November 2015 (has links)
<p>U uvodnom delu doktorske disertacije opisuje se kompleksnost problematike kori&scaron;ćenja polimera za bazu zubne proteze, sa osvrtom na njihove op&scaron;te osobine, stepen biokompatibilnosti i njihove mehaničke karakteristike. Detaljno je opisana problematika ispitivanja stomatolo&scaron;kih materijala i napravljeno je poređenje i korelacija između in vitro i in vivo načina ispitivanja biokompatibilnosti. Drugi deo obuhvata ispitivanje čvrstoće polimera za bazu zubne proteze i analizu uticaja osobina materijala u odnosu na biolo&scaron;ku sredinu u kojoj obavljaju svoju funkciju, i u odnosu na sile kojima su tokom funkcije materijali izloženi. Cilj doktorske disertacije je utvrđivanje stepena biokompatibilnosti i mehaničkih karakteristika toplopolimerizujućih, hladnopolimerizujućih i termoplastičnih akrilata za bazu zubne proteze. Istraživanje je obuhvatilo 3 komercijalna materijala iz grupe akrilata, koji se razlikuju po hemijskom sastavu i načinu polimerizacije. Ispitivanje biokompatibilnosti rađeno je u in vitro i in vivo uslovima. Ispitivanje na ćelijskim kulturama obuhvatalo je dve ćelisjke linije (MRC 5 i L929) sa dva načina kontakta između ćelija i materijala (direktan, indirektan) i dva načina određivanja biolo&scaron;kog ishoda (MTT test, Agar difuzioni test). Istraživanje urađeno in vivo obuhvatalo je test subkutane implantacije, na animalnom modelu pacova, i test iritacije oralne sluzokože na animalnom modelu hrčka. Oba testa rađena su u skladu sa standardom ISO 10993. Cilj in vivo istraživanja bio je ispitivanje reakcije tkiva na implantirani materijal, računajući i zavr&scaron;nu integraciju ili dezintegraciju implantiranog materijala. Prednost in vivo istraživanja nalazi seu analizi uticaja materijala na sterilno živo tkivo, uz praćenje imunolo&scaron;ke reakcije, kao dopuna prethodnom istraživanju na ćelijskim kulturama. Dopunski deo in vivo ispitivanja biokompatibilnosti određen je prema kliničkoj upotrebi ispitivanih materijala, zbog čega je odabran test oralne iritacije sluzokože. Sluzokoža bukalne kesice sirijskog hrčka sastoji se od pločasto slojvitog epitela sa orožavanjem, &scaron;to je predstavljao dobar model za ispitivanje polimera za bazu zubne proteze, po&scaron;to zubna proteza naleže na sluzokožu nepca i rezidualnog alveolarnog grebena koja takođe orožava. Drugi deo disertacije obuhvatao je ispitivanje mehaničkih karakteristika, pri čemu su urađeni test zatezne čvrstoće, test savojne čvrstoće, test čvrstoće loma i mikrotvrdoće, uz dopunsku analizu pratećih parametara. Rezultati ispitivanja biokompatibilnosti pokazali su da su testovi biokompatibilnosti osetljivi na upražnjeni metodolo&scaron;ki postupak. Ispitivanjem na ćelijskim kulturama nisu utvrđene značajne razlike u citotoksičnosti između toplopolimerizujućih, hladnopolimerizujućih i termoplastičnih akrilata. Takođe, rezultati su se razlikovali u odnosu na tip ćelijske kulture i način provere biolo&scaron;kog ishoda, &scaron;to se slaže sa prethodnim navodima o kompleksnoj problematici njihovog međusobnog poređenja. Ispitivanjem biokompatibilnosti subkutanom implantacijom praćen je inflamatorni odgovor tkiva u vremenskom intervalu od 90 dana. Reakcija organizma na implantirani materijal posmatrana je kroz ćelijske i tkivne parametre, u skladu sa ISO 10993. Dodatno je urađena i analiza hrapavosti implantiranih materijala. Histolo&scaron;kom analizom utvrđena je razlika u inflamatornom odgovoru u odnosu na kori&scaron;ćeni materijal, kao i prema vremenskom intervalu implantacije. Test oralne iritacije sluzokože nije se pokazao kao dovoljno senzitivan za ispitivanje ovih vrsta materijala. Ispitivanjem mehaničkih karakteristika utvrđene su razlike između toplopolimerizujućih, hladnopolimerizujućih i termoplastičnih akrilata. Najveći stepen čvrstoće utvrđen je kod toplopolimerizujućih akrilata dok je najveća konzistentnost rezultata bila u grupi termoplastičnih akrilata. Prezentovano istraživanje predstavlja prvu detaljnu analizu biokompatibilnosti i mehaničkih karaktestistika polimera za bazu zubne proteze.</p> / <p>The introduction describes the complexity of use of denture base materials, with regard to their general characteristics, biocompatibility and mechanical properties. Issues related to the testing of dental materials is described in detail and comparison is made between in vitro and in vivo methods of biocompatibility testing. The second part further covers the determination of strength of previously used materials, in relation to biological environment in which their function is conducted and in relation to the influence of masticatory forces which can contribute to their mechanical failure. The aim of the presented research was to assess the degree of biocompatibility and mechanical properties of cold curing, hot curing and thermoformed denture base materials. The research included three denture base materials, which differed according to their chemical composition and polymerization protocols. The biocompatibility testing was carried out in in vitro and in vivo conditions. The in vitro experiments covered two different cell lines (MRC 5 human lung fibroblasts and L929 mouse fibroblasts) with two types of contact (direct, indirect) and two different types of quantification of biological outcome (MTT assay and Agar overley test). The in vivo assessment of biocompatibility covered the subcutaneous implantation test, on the animal model of Wistar rat, and oral mucosa irritation test, on the animal model of sirian hamster. Both tests were conducted according to the ISO 10993. The aim of the in vivo investigation was to evaluate tissue reactions to the implanted materials, including the final integration or disintegration of the tested materials. The advantage of in vivo investigation included the possibility of monitoring the materials influence on living tissues, with the analysis of imunological response as an addition to the previously conductedresearchon cell cultures. The supplemental part of in vivo investigation was chosen according to the clinical use of the tested materials, which included the oral mucosa irritation test.The mucosa of hamster buccal pouch consists of stratified squamos epithelium, which is considered to be an adequate replacement for the human denture supporting tissues, which also consist of the same type of epithelium. The second part of thesis includes the determination of mechanical properties of denture base materials. It consists of four types of tests: tensile strength test, bending strength test, fracture toughness test and microhardness tests, followed by the analysis of corresponding parameters. The results of the biocompatibility tests showed that the biological outcome of the applied method is highly depended on the methodological procedure. The investigation conducted in vitro, on two different cell lines, did not show significant difference in cytotoxicity between hot curing, cold curing and thermoformed denture base materials. Also, the results were influenced by the type of cell culture and the evaluation method of biological outcome, which agrees with the previous allegations about the complexicity of their mutual comparison. The subcutaneous implantation test covered the inflammatory response in the time period of 90 days. The organism reaction to the implanted material was determined through the cell and tissue parameters of organism response, evaluation of which was conducted according to the ISO 10993. Additionally, the surface roughness of the implanted specimens of materials was also measured. The inflammatory response of the ogranism was influenced by the type of the implanted material and the time interval of implantation. The oral mucosa irritation test has proven not to be sufficiently sensitive for testing of this type of materials. Testing of the mechanical properties od denture base materials, revealed the difference between the cold curing, hot curing and thermofomed denture base materials. The highest strength was observed in hot curing materials, while the highest consistency of the results was observed in thermoformed resins. The presented investigation presents the first detail analysis of the biocompatibility and mechanical properties of the denture base materials, and as such presents a novelty in the field of dental materials characterization.</p>
110

Development and evaluation of a research-based prosthodontic clinical record

Ahmadi, Motahareh 04 1900 (has links)
Introduction: Bien que l'importance de transférer les données de la recherche à la pratique a été largement démontrée, ce processus est toujours lent et fait face à plusieurs défis tels que la conceptualisation des évidences, la validité interne et externe de la recherche scientifique et les coûts élevés de la collecte de grandes quantités de données axées sur le patient. Les dossiers dentaires des patients contiennent des renseignements valables qui donneraient aux chercheurs cliniques une opportunité d'utiliser un large éventail d'informations quantitatives ou qualitatives. La standardisation du dossier clinique permettrait d’échanger et de réutiliser des données dans différents domaines de recherche. Objectifs: Le but de cette étude était de concevoir un dossier patient axé sur la recherche dans le domaine de la prosthodontie amovible à la clinique de premier cycle de l’Université de Montréal. Méthodes: Cette étude a utilisé des méthodes de recherche-action avec 4 étapes séquentielles : l'identification des problèmes, la collecte et l'interprétation des données, la planification et l’évaluation de l'action. Les participants de l'étude (n=14) incluaient des professeurs, des chercheurs cliniques et des instructeurs cliniques dans le domaine de la prosthodontie amovible. La collecte des données a été menée à l’aide d’une revue de littérature ciblée et complète sur les résultats en prosthodontie ainsi que par le biais de discussions de groupes et d’entrevues. Les données qualitatives ont été analysées en utilisant QDA Miner 3.2.3. Résultats: Les participants de l'étude ont soulevé plusieurs points absents au formulaire actuel de prosthodontie à la clinique de premier cycle. Ils ont partagé leurs idées pour la conception d'un nouveau dossier-patient basé sur 3 objectifs principaux: les objectifs cliniques, éducatifs et de recherche. Les principaux sujets d’intérêt en prosthodontie amovibles, les instruments appropriés ainsi que les paramètres cliniques ont été sélectionnés par le groupe de recherche. Ces résultats ont été intégrés dans un nouveau formulaire basé sur cette consultation. La pertinence du nouveau formulaire a été évaluée par le même groupe d'experts et les modifications requises ont été effectuées. Les participants de l'étude ont convenu que le cycle de recherche-action doit être poursuivi afin d'évaluer la faisabilité d’implémentation de ce dossier modifié dans un cadre universitaire. Conclusion: Cette étude est une première étape pour développer une base de données dans le domaine de la prothodontie amovible. La recherche-action est une méthode de recherche utile dans ce processus, et les éducateurs académiques sont bien placés pour mener ce type de recherche. / Introduction: Although the importance of research translating into practice has been widely recognized, this process is still slow and faces several barriers such as conceptualizations of evidence, internal and external validity of the evidence and high costs of providing large amounts of patient-based outcome data. Patient’s dental records contain valuable information that would give clinical researchers an opportunity to use a wide range of quantitative or qualitative information. Standardization of clinical record would allow the interoperability and reusability of data in different research fields. Objectives: The aim of this study was to design a research-based patient record in the field of removable prosthodontics in the undergraduate clinic of the “Université de Montréal.” Methods: This study used action research methods with 4 sequential steps: problem identification, gathering and interpreting data, action planning, and action evaluation. Study participants included professors, clinical researchers, and clinical instructors in the field of removable prosthodontics. Data collection consisted of a comprehensive literature review on prosthodontic outcomes as well as focus-group discussions and interviews. The qualitative data were analysed using QDA Miner 3.2.3. Results: The study participants raised several concerns about the deficiencies of the existing patients’ prosthodontic record in the undergraduate clinic. They shared their ideas for designing a new patient record based on 3 key objectives: clinical, educational, and research objectives. The prosthodontic outcomes of interest and appropriate instruments as well as the clinical parameters were selected by the research group and were integrated into a new research-based record. The appropriateness of the new record has been evaluated by the same panel of experts and the necessary modifications have been carried out. The study participants agreed that the action research cycle should be continued to evaluate the feasibility of the implementation of this redesigned record in the university-based setting. Conclusion: This study is a beginning effort to develop a database in the field of removable prosthodontics. Action research is a useful research method in this process, and academic educators are well placed to conduct such research.

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