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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.
51

A mechanical and histological study of functionally graded hydroxyapatite implant coatings

Coco, Suzanne Kemp, January 2008 (has links) (PDF)
Thesis (M.S.)--University of Tennessee Health Science Center, 2008. / Title from title page screen (viewed on June 10, 2008). Research advisor: Joo Leng Ong, Ph.D. Document formatted into pages (vi, 34 p. : ill.). Vita. Abstract. Includes bibliographical references (p. 31-34).
52

The influence of biofilm on the antifungal activity of amine oxide

Hart, Jonathan Michael, January 2009 (has links) (PDF)
Thesis (M.S.)--University of Tennessee Health Science Center, 2009. / Title from title page screen (viewed on August 11, 2009). Research advisor: Jegdish P. Babu, Ph.D. Document formatted into pages (ix, 32 p. : ill.). Vita. Abstract. Includes bibliographical references (p. 28-31).
53

Effect of interim fixed prosthodontics materials and flowable composite resins on polymerization of polyvinyl siloxane impressions

Alsayed, Hussain D. January 2017 (has links)
Indiana University-Purdue University Indianapolis (IUPUI)
54

The influence of heat production relative to drill wear during osteotomy preparation by different implant drill systems a comparison study between ceramic and conventional implant drill systems /

Alyassin, Waleed. January 2010 (has links)
Thesis (M.S.)--West Virginia University, 2010. / Title from document title page. Document formatted into pages; contains vi, 41 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 37-41).
55

Torque required to loosen surface treated abutment screws before and after cyclic loading a thesis submitted in partial fulfillment ... for the degree of Master of Science in Restorative Dentistry ... /

Falcao, Felipe A. January 2001 (has links)
Thesis (M.S.)--University of Michigan, 2001. / Includes bibliographical references.
56

Restorative Characteristics of Intrapulpally Cracked Teeth

Beavers, Charles M 01 January 2015 (has links)
Cracked teeth have long presented a diagnostic challenge. Previous investigators have considered possible predictive factors, many of which revolve around the tooth’s restorative characteristics. Few have investigated the restorative status of teeth with cracks extending into the pulp chamber. The purpose of this investigation was to determine the prevalence of the different types of restorations present in intrapulpally cracked teeth and determine any other restorative factors that may aid in predicting the presence or extent of an intrapulpal crack. Intrapulpally cracked molars requiring endodontic therapy at the VCU Graduate Endodontic Practice were included in this study. For each tooth, the type of restorative material present and surfaces involved were recorded. The Restoration Volume Proportion (RVP) was calculated to accurately quantify the size of the restoration present. Pulpal and periapical diagnoses, and intrapulpal crack classification were also recorded. Chi squared analysis and logistic regression were used to determine any significant associations. This study included 43 teeth. The study population was 65% female and the average age was 56. Of the various restoration types evaluated, 73% of teeth presented with amalgams, 12% with composites. Class I restorations were 61% of the sample. The most frequently occurring restoration size by volume was a “small” restoration. The most commonly involved teeth were the maxillary 1st molar and mandibular 2nd molar. A significant association was found between restoration size and crack classification suggesting that teeth with larger restorations had a higher incidence of coronal cracks while those with smaller restorations had a higher incidence of radicular cracks. Restoration classification and pulpal walls involved were also significantly associated suggesting that Class II restorations were most frequently associated with cracks involving a single pulpal wall while Class I restorations were evenly associated with one and two wall cracks. Other significant associations were found between tooth type and pulpal walls involved and between restoration surfaces and pulpal wall classification. This study found several significant associations between restoration characteristics and intrapulpal cracks. Further research may continue to reveal how a tooth’s restorative status may influence its risk for the presence of an intrapulpal crack.
57

THE BOND STRENGTH OF ADHESIVE RESIN CEMENT: TIME DIFFERENTIAL BETWEEN CEMENTATION AND FINISHING OF CAST DOWEL-CORES

Shahani, Purnima Joan 01 January 2003 (has links)
THE BOND STREGTH OF ADHESIVE RESIN CEMENT: TIME DIFFERENTIAL BETWEEN CEMENTATION AND FINISHING OF CAST DOWEL-CORES By Purnima Joan Shahani, D.D.S., M.S.A Thesis submitted in partial fulfillment of the requirements for the degree of Master of Science in Dentistry at Virginia Commonwealth University.Virginia Commonwealth University, 2003Major Director: Peter C. Moon, M.S., PhDDirector of VCU Dental Biomaterials LaboratoryThis study compared the retention of cast dowel-cores cemented with Panavia® 21 subjected to immediate versus delayed high-speed finishing. Conventionally, finishing is delayed for 24 hours to one week to allow for optimal setting and ultimate strength of the cement. Forty-five recently extracted human maxillary canines were used. Teeth were divided among 3 groups: a control group (n=15, no finishing), an immediate finishing group (n=15, high-speed cutting of the cores performed five minutes after cementation) and a delayed finishing group (n=15, high-speed finishing performed 48 hours post-cementation). Tensile load to failure was applied using an Instron® at a crosshead speed of 0.05 inches/minute. A statistical test of equivalence was performed. The average retention force associated with failure after immediate finishing was not found to be inferior to delayed finishing failure force. In fact, post-hoc comparisons indicated that immediate finishing has statistically significant greater mean retentive force when compared to this force for delayed finishing at p = 0.00001.
58

Avaliação clínica de próteses dentárias metálicas em felídeos selvagens mantidos em cativeiro / Clinical evaluation of metallic dental prostheses in wild felids kept in captivity

Fecchio, Roberto Silveira 24 November 2016 (has links)
Fraturas dentárias são enfermidades de alta prevalência entre os carnívoros selvagens, principalmente em animais cativos. Esse tipo de afecção é comum em grandes felídeos, cujos hábitos e aspectos biológicos contribuem para o traumatismo dentário. A superfície dental é capaz de suportar certo limite fisiológico de atrito e, caso esse limite seja superado, há desgaste excessivo das estruturas dentárias que pode evoluir para fratura. O tratamento preconizado envolve endodontia (tratamento de canal) e prostodontia (restauração coronal). Próteses unitárias são aquelas que restauram a coroa de um dente cuja estrutura fora parcial ou totalmente perdida. Foram cimentadas 19 (N=19) restaurações metálicas fundidas (RMF) com auxílio de cimento resinoso dual, dentre as quais, 14 (73%) mantiveram-se fixas ao dente e 5 (27%) foram perdidas, por um ou mais motivos. Em relação ao sexo, um animal era macho (11%) e os 8 demais eram fêmeas (89%). Dentre as perdas protéticas (5 = 100%), uma (20%) ocorreu em período inferior a um mês e 4 (80%) entre 9 e 14 meses. Destas, uma (20%) ocorreu em função de fratura do remanescente dentário e 4 (80%) não se sabe a causa da perda protética. Dentre as próteses mantidas (14 = 100%), um (7%) dos animais morreu durante o estudo e 13 (93%) mantem-se vivos e com as peças protéticas fixas aos dentes. Quando se trata de animais selvagens, devolver a função é o objetivo mais importante da restauração, objetivo principal deste estudo / Dental fractures are highly prevalent among wild carnivores, mainly in captive animals. This type of condition is common in large felids, whose habits and biological aspects contribute to dental trauma. The tooth surface is capable of supporting certain physiological limit of friction, and if this limit is exceeded, there is excessive wear of the dental structures that can lead to fracture. The recommended treatment involves endodontics (root canal treatment) and prosthodontics (coronal restoration). Unitary prostheses are those that restore the crown of a tooth which structure had been partially or completely lost. Among the 19 (N = 19) cemented prostheses in this study with dual ciment, 14 (73%) remained fixed to the tooth and 5 (27%) were lost for one or more reasons. Regarding sex, an animal was male (11%) and 8 others were females (89%). Among the prosthetic losses (5 = 100%), one (20%) occurred in less than one month and 4 (80%) between 9 and 14 months. Of these, one (20%) occurred in the remaining tooth fracture function and 4 (80%) the cause of prosthetic loss was not known. Among the retained prosthesis (14 = 100%), one (7%) of the animals died during the study and 13 (93%) are still alive and the prosthetic pieces still fixed to the teeth. When it comes to wildlife, return the function is the most important goal of the restoration, the main objective of this study
59

Dental zirconia: in-vitro comparison and outcome of methods for veneering, glazing, and chipping repairs

Kumchai, Hattanas 28 September 2016 (has links)
OBJECTIVE: The purpose of this study is to evaluate the experimental properties of zirconia-based ceramics. METHODS: Zirconia bars were veneered to 2mm total thickness. Veneering-method groups included: 1.Hand-layered feldsparthic porcelain (VM=VitaVM9,Vident) and fluorapatite glass-ceramic (CR=IPSe.maxCeram,IvoclarVivadent); 2.Pressed feldspathic porcelain (PM=VitaPM9,Vident) and fluorapatite glass-ceramic (ZP=IPSe.maxZirPress,IvoclarVivadent); 3.CAD/CAM milled feldspathic ceramic (TF=VitablocsTriluxeForte,Vident) and lithium-disilicate glass-ceramic (CAD=IPSe.maxCAD,IvoclarVivadent). CAD/CAM veneers were either cemented with resin cements (P=Panavia21,KurarayDental), (R=RelyXUltimate,3M ESPE), (M=MultilinkAutomix,IvoclarVivadent) or fused with fusion glass-ceramic (C=CrystalConnect,IvoclarVivadent). A Three-point-bending test was performed. For group VM,PM,TF-M,TF-C,CAD-M,CAD-C, ten more bars were prepared and aged with cyclic loading and thermocycling before testing. Zirconia bars (PrettauZirconia,Zirkonzahn;inCorisTZI,Sirona;ZirluxFC,PentronCeramics) specimens were prepared and polished. The specimens were divided into 3 groups: control, self-glaze fired, and glazed groups. A Three-point bending test was performed. Veneered zirconia crowns were made. Feldspathic porcelain was applied to zirconia coping. Bevel cut on porcelain was made to simulate porcelain chipping. The crowns were then divided into 4 different groups according to repair materials including: 1.Conventional-resin composite (TetricEvoCeram,IvoclarVivadent) 2.Flowable-resin composite (G-aenialUniversalFlo,GCamerica) 3.Cemented CAD/CAM milled feldspathic ceramic (VitaTriluxForte,Vident) 4.Cemented CAD/CAM milled lithium-disilicate glass-ceramic (IPSe.maxCAD,IvoclarVivadent). Each crown underwent thermocycling. The test was performed by loading force on the center of repaired part to record load-to-failure. RESULTS: There were significant differences in the failure loads of non-aged bilayered veneer-zirconia bars. Aging experiment revealed a significant difference in failure load between non-aged and aged bars in groups VM and PM, but not in the groups with CAD/CAM milled veneers. There was significant influence of surface treatments on flexural strength of zirconia specimens. Post-hoc test showed that glazed group had significant lower flexural strength than other groups. Crowns repaired with CAD/CAM ceramics showed significant higher failure load than resin composite. Repairing with lithium-disilicate glass ceramic yielded the highest load-to-failure of the specimens. CONCLUSIONS: - Veneer materials, veneering methods, and cement materials have a significant effect on the failure load of bilayered veneer- zirconia. CAD/CAM veneer-zirconia is not susceptible to aging performed in this study. - Glazing decreased the flexural strength of high translucent zirconia. - Veneered zirconia crowns repaired with CAD/CAM ceramic materials have significantly higher load-to-failure than veneered crowns repaired with resin composite. / 2018-09-28T00:00:00Z
60

Minimal inhibitory concentration of antimicrobial and antifungal agents in denture adhesive material against Candida albicans

Garaicoa Pazmino, Jorge Luis 01 December 2014 (has links)
Approximately 26% of the U.S. population between the ages of 65 and 74 years are completely edentulous. Of the different proposed predictors and risk factors, low income and education levels have the highest correlation with tooth loss. While the incidence of complete edentulism in the United States has progressively declined over the past decade, the continued growth of the population strongly suggests that edentulism prevalence will likely remain constant or increase over the next few decades. In patients wearing complete prosthetic appliances, several post-treatment complications may arise, including denture associated Candida species infections and mucosal stomatitis. These type of fungal infections are associated with patient-reported symptoms (e.g. pain or discomfort) and may impede normal oral function. In this study the activity of 11 (antimicrobial and/or antifungal) agents in a dental adhesive carrier against two strains of C. albicans was assessed. In conventional minimal inhibitory concentration (MIC) assays, C. albicans were resistant to histatin 5 and lactoferricin B, yet very susceptible to SMAP28; susceptible to long chain bases sphingosine, dihydrosphingosine, and phytosphingosine; and susceptible to anti-fungal agents amphotericin B, chlorhexidine dihydrochloride, chlorhexidine gluconate, fluconazole, and nystatin. However, in 1% dental adhesive (final concentration) C. albicans were resistant to histatin 5, lactoferricin B, SMAP28, sphingosine, dihydrosphingosine, and phytosphingosine suggesting that the components in denture adhesive may inactivate local innate immune factors in the oral cavity possibly predisposing users to fungal infections in relation to their dental prostheses. In MIC assays in 1% dental adhesive (final concentration) C. albicans were susceptible (p value < 0.05) to amphotericin B, chlorhexidine, dihydrochloride, chlorhexidine gluconate, fluconazole, and nystatin strongly suggesting that these anti-fungal agents could be candidates for inclusion in denture adhesive formulations, and also be used as a prescribed topical treatment in individuals with fungal infections of the oral mucosa.

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