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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

Comparing the effectiveness of a new innovative desensitizing paste to a home-used desensitizing toothpaste in reducing dentine hypersensitivity among Chinese adults

Chan, Kit-ping, Cordelia, 陳潔萍 January 2014 (has links)
This study aimed to compare the effectiveness of an 8% arginine and calcium carbonate in-office desensitizing prophylaxis paste with that of a home-use toothpaste having the same active ingredients in reducing dentine hypersensitivity. The study was a randomized controlled clinical trial involving 55 subjects who had at least one tooth with sound exposed dentine on the cervical region of the buccal surface displaying hypersensitivity. The subjects were recruited from students and staff, other than those from the Faculty of Dentistry, of The University of Hong Kong. After receiving scaling performed by a dental hygienist at baseline, subjects were randomly assigned to either the in-office desensitizing prophylaxis paste treatment group or the home-use desensitizing toothpaste group. Clinical assessments of dentine hypersensitivity to tactile and to thermal stimuli were performed prior to the treatment at baseline, week 4 and week 12 by a blinded examiner and subjective global assessments of dentine hypersensitivity were recorded. The responses of the subjects to both stimuli were recorded by using a pain score scale from 0 to 10 (from no pain to unbearable pain). Reponses to both tactile and thermal hypersensitivity assessments in the home-use desensitizing toothpaste group showed statistically significant differences between baseline and week 12 (tactile: 2.4 vs. 0.9; cold: 5.8 vs. 3.5, both p<0.05). There was a statistically significant difference in the tactile assessment scores (1.8 vs. 1.0, p<0.05) but not in the thermal hypersensitivity assessment scores (5.5 vs. 5.3, p>0.05) for the in-office desensitizing prophylaxis paste group. There was also a statistically significant difference in the change in thermal assessment scores between the two groups (in-office: -0.2 vs. home-use: -2.3, p<0.05) but not in the tactile hypersensitivity assessment scores (in-office: -0.9 vs. home-use: -1.2, p>0.05). There were no statistically significant differences in global subjective responses to external stimuli in the telephone interviews. Daily use of an 8% arginine and calcium carbonate toothpaste was able to reduce dentine hypersensitivity over 12 weeks but a single in-office application of prophylaxis paste of similar content was not able to provide instant and long-lasting benefits for subjects with a mild-to-moderate degree of dentine hypersensitivity. / published_or_final_version / Dentistry / Master / Master of Philosophy
2

Nutritional stresses and the feeding behaviour and activity patterns of free-ranging koalas (Phascolarctos cinereus : Goldfuss)

Logan, Murray January 2003 (has links)
Abstract not available
3

Oral health status and quality of life of children and adolescents with severe hypodontia

Wong, Tak-ying, Anita., 黃德瑩. January 2003 (has links)
published_or_final_version / Dentistry / Master / Master of Dental Surgery
4

Wear studies of enamel and some restorative materials

Shabanian-Borojeni, Mitra. January 2001 (has links) (PDF)
Includes bibliographical references (leaves [1-20]). A systematic analysis of wear involving the in vitro analysis of the wear of standard composite resin and glass ionomer cements restorations under controlled conditions; and, the qualitative and quantitative investigation of wear over a range of pH's and loads which might be encountered clinically in order to develop a "wear map" of the micromorphology of wearing teeth and restorations and a systematic modeling of wear rates.
5

An experimental study of the wear characteristics of human enamel during tooth grinding / John Aristidis Kaidonis.

Kaidonis, John A. January 1995 (has links)
Copies of author's previously published articles inserted. / Bibliography: leaves 136-155. / xxi, 180 leaves : ill. (some col.) ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Examines tooth-to-tooth contact under controlled experimental conditions that simulate bruxism. Focuses on the wear characteristics of enamel and factors influencing the nature and extent of human enamel wear. / Kaidonis, John Aristidis / Thesis (Ph.D.)--University of Adelaide, Dept. of Dentistry, 1995?
6

Wear studies of enamel and some restorative materials / Mitra Shabanian-Borojeni.

Shabanian-Borojeni, Mitra January 2001 (has links)
Includes bibliographical references (leaves [1-20]). / xxi, 168, [20] leaves : ill. (some col.) ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / A systematic analysis of wear involving the in vitro analysis of the wear of standard composite resin and glass ionomer cements restorations under controlled conditions; and, the qualitative and quantitative investigation of wear over a range of pH's and loads which might be encountered clinically in order to develop a "wear map" of the micromorphology of wearing teeth and restorations and a systematic modeling of wear rates. / Thesis (Ph.D.)--University of Adelaide, Dept. of Dentistry, 2001
7

Efeito de metodos de polimento na rugosidade e dureza Vickers de ceramicas para cobertura / The effect of the polishing method on roughness and Vickers hardness on dental ceramics

Muzilli, Marcelo, 1972- 02 September 2009 (has links)
Orientador: Lourenço Correr Sobrinho / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba / Made available in DSpace on 2018-08-13T01:39:57Z (GMT). No. of bitstreams: 1 Muzilli_Marcelo_D.pdf: 34149055 bytes, checksum: 91212ba7ea6406d835e270899c5d9256 (MD5) Previous issue date: 2009 / Resumo: O objetivo deste estudo foi avaliar o efeito do método de polimento na rugosidade e na dureza Vickers de doze cerâmicas utilizadas para cobertura, após serem submetidas ao desgaste abrasivo. Foram confeccionados quarenta discos de cada cerâmica, cor de esmalte, com 8 mm de diâmetro e 2 mm de espessura. O pó cerâmico de cada marca comercial (CERAMCO, CERCON, FINESSE, IPS D.SIGN, IPS ERIS, VINTAGE HALO, VISION, VISION ESTHETIC, VITA VM7, VITA VM9, VITA VM13 e WILL CERAM) foi aglutinado com o líquido modelador indicado e aplicado em uma matriz metálica bipartida. Após a sinterização e o esfriamento, os discos foram desgastados, simulando uma situação de ajuste oclusal, com ponta diamantada 3098 F e 3098 FF (KG Sorensen), e divididos em 4 grupos (n=10): Grupo P - polimento com abrasivos do sistema Shofu; Grupo PP - polimento com sistema Shofu + pasta diamantada (6 mm - KG SORENSEN); Grupo PG - polimento + glaze e Grupo G - glaze (Controle). Os corpos-de-prova foram levados ao rugosímetro Surf-Corder para mensuração da rugosidade de superfície, utilizando o parâmetro Ra. Foram feitas três mensurações em cada corpo-de-prova. A dureza Vickers foi efetuada no aparelho HMV-2 (Shimadzu), calibrado com carga de 9,8 N atuando por 15 segundos. Cinco penetrações foram feitas em cada corpo-de-prova e a média calculada. Os dados foram submetidos à Análise de Variância e ao teste de Tukey (5%) e mostraram que as cerâmicas Finesse, VM7, VM9, VM13 e IPS Eris não tiveram influência do método de polimento na dureza Vickers. Os menores valores de dureza Vickers foram obtidos pelas cerâmicas Vintage Halo e VM7 no grupo P; Cercon, Vintage Halo, VM9 e Ceramco no grupo PP; Cercon no grupo PG e Ceramco, Cercon, Will Ceram e Vision Esthethic no grupo G. Os métodos de polimento tiveram influência na rugosidade em todas as cerâmicas utilizadas. Os menores valores de rugosidade foram obtidas pelas cerâmicas VM9, VM13, VM7, IPS Eris, Ceramco e Vintage Halo, no grupo P; Will Ceram, VM7, VM13 e Vintage no grupo G e Will Ceram, VM7 e Vision no grupo PG. O grupo PP promoveu os menores valores de rugosidade não diferindo entre as cerâmicas utilizadas. / Abstract: The aim of this study was to evaluate the polish method influence on surface roughness and Vickers hardness number of the twelve dental ceramics, after abrasive grinding. Forty enamel ceramic disks with 8 mm in diameter and 2.0mm thickness were made. The ceramic powder for each brand (CERAMCO, CERCON, FINESSE, IPS D.SIGN, IPS ERIS, VINTAGE HALO, VISION, VISION ESTHETIC, VITA VM7, VITA VM9, VITA VM13 and WILL CERAM) was agglutinated with the appropriate modeling liquid and applied on a bipartite metallic matrix. After the sinterization and cooling, the disks were submitted to a simulation of oclusal adjustment with 3098 F and 3098 FF diamonds burs (KG SORENSEN), and divided into four groups (n=10): Group P - Shofu polishing system; Group PP - Shofu polishing system + diamond paste (6mm - KG SORENSEN); Group PG - Shofu polishing system + glaze; and, Group G - glaze (control). The roughness was measured on a Surf-Corder machine using Ra parameter. Three measurements were made for each specimen and the average calculated. The Vickers hardness number was measured with HMV 2 microhardness tester (Shimadzu), with a load of 9,8 N applied for 15 seconds. Five measurements were made for each specimen. The dates were submitted to ANOVA and Tukey's test (5%) and showed that only the ceramics FINESSE, VM7, VM9, VM13 and IPS ERIS weren't the influence of surface treatment on Vickers hardness. The lowers hardness values were obtained by Cercon, Vintage Halo and VM7, in group P; Cercon, Vintage Halo, VM9 and Ceramco in Group PP; Cercon, in Group PG; Ceramco, Cercon, Will Ceram and Vision Esthetic, in Group G. The roughness suffered the influence of the surface treatment in all the ceramics that were used. The lowers roughness values were obtained by VM9, VM13, VM7, IPS Eris, Ceramco and Vintage Halo, in Group P; Will Ceram, VM7, VM13 e Vintage in Group G and Will Ceram, VM7 e Vision in Group PG. The Group PP promoted the lowers roughness averages that didn't show any difference statistic among all the ceramics. / Doutorado / Materiais Dentarios / Doutor em Materiais Dentários
8

Efeito dos desafios erosivo ou erosivo/abrasivo sobre as estruturas dentárias adjacentes às restaurações realizadas com materiais contendo fluoreto ou cálcio / Effect of erosive and erosive/abrasive challenges on the dental hard tissues adjacent to restorations performed with materials containing fluoride or calcium

Viana, Ítallo Emídio Lira 29 January 2018 (has links)
Esse estudo avaliou in vitro o efeito dos desafios erosivo ou erosivo/abrasivo sobre materiais restauradores contendo fluoreto ou cálcio e sobre as estruturas dentárias adjacentes às restaurações realizadas com esses materiais. Fragmentos de esmalte e de dentina bovinos (4 mm × 4 mm × 2 mm), foram incluídos em resina acrílica e planificados. Uma cavidade padrão com dimensões 1,2 mm × 4 mm × 1,5 mm foi preparada nos espécimes, e restaurada de acordo com o material a ser testado: 1. Z350 - resina composta (Filtek Z350, 3M ESPE); 2. VB - compósito experimental contendo apenas vidros de bário; 3. DCPD30% - compósito experimental contendo 10% de vidros de bário e 30% partículas de fosfato di-cálcio di-hidratado (DCPD) funcionalizadas com dimetacrilato de dietilenoglicol (DEGDMA); 4. DCPD60% - compósito experimental contendo 60% partículas de DCPD funcionalizadas com DEGDMA; 5. Beautifil - GIOMER (Beautifil II, Shofu Dental Corporation); 6. Fuji IX - cimento de ionômero de vidro convencional de alta viscosidade (Fuji IX, GC Corporation); 7. Fuji II LC - cimento de ionômero de vidro modificado por resina (Fuji II LC, GC Corporation). Na sequência, os espécimes foram polidos e submetidos a dois tipos de tratamentos: erosão somente (n=10) ou erosão mais abrasão por escovação (n=10). A erosão foi realizada pela imersão dos espécimes em ácido cítrico a 0,3% (pH~2,6) por 5 min, seguido de 60 min de imersão em saliva artificial. Esse procedimento foi repetido 4×/dia, por 5 dias. A escovação foi realizada com uma suspensão de dentifrício padrão (Colgate Total 12 Mint Clean; 1450 ppm F-, como NaF) por 15 s (2 min de exposição total a suspensão de dentifrício), 2×/dia, 30 min após o primeiro e o quarto desafios erosivos. Ao final da ciclagem, a perda superficial (em ?m) do esmalte, da dentina e dos materiais restauradores foi determinada com um perfilômetro ótico. Para cada modelo (erosão e erosão-abrasão), os dados de perda superficial de esmalte, dentina e restauração foram analisados de maneira independente. Os dados foram analisados pelos testes de Kruskal-Wallis e Tukey. O nível de significância utilizado foi de 5%. No modelo de erosão, para esmalte, ambos cimentos ionoméricos apresentaram menor perda superficial do que o compósito Z350, apesar de Fuji II LC não ter se diferenciado significativamente dos grupos Beautifil e DCPD30%. Os outros grupos não foram diferentes de Z350 nem entre si. Para dentina, nenhum dos grupos foi diferente de Z350, com exceção de DCPD60%, o qual apresentou a maior perda superficial. Ambos cimentos ionoméricos apresentaram menor perda do que DCPD30%, Beautifil e DCPD60%. Em relação à restauração, os materiais Z350, Beautifil, VB, DCPD30% apresentaram perda superficial mínima, sem diferenças entre eles. Os cimentos ionoméricos apresentaram os maiores valores de perda, não se diferenciando de DCPD60%. No modelo erosão-abrasão, para esmalte, a menor perda superficial foi observada em Fuji II LC, sem diferença da Beautifil. Os outros grupos não se diferenciaram entre si nem da Beautifil. Para dentina, os grupos DCPD60%, Beautifil, Fuji II LC, Z350 e Fuji IX não se diferenciaram e, apresentaram menor perda superficial do que VB. Os cinco grupos citados também não foram diferentes de DCPD30%, com exceção de Fuji IX. Em relação à restauração, a maior perda foi observada para Fuji IX, sem diferenças de Fuji II LC e Beautifil. DCPD30%, Z350, VB e DCPD60% apresentaram valores mínimos de perda superficial, sem diferenças entre si. Concluiu-se que o cimento ionomérico Fuji II LC foi único capaz de proteger o esmalte adjacente à restauração contra desafios erosivos e erosivos/abrasivos, apesar de ter sido um dos materiais mais susceptíveis ao desgaste por ambos desafios. Para dentina, nenhum material exibiu efeito protetor. / This in vitro study evaluated the effect of erosive or erosive/abrasive challenges on restorative materials containing fluoride and calcium, and on the dental hard tissues adjacent to restorations performed with these materials. Enamel and dentin specimens (4 mm × 4 mm × 2 mm), obtained from bovine incisors, were embedded in acrylic resin, flattened and polished. In the specimens, a standard cavity of 1,2 mm × 4 mm × 1,5 mm was prepared and restored with the following materials: 1. Z350 - Composite resin without actives, Filtek Z350 (3MESPE); 2. VB - experimental composite containing barium glass only; 3. DCPD30% - experimental composite containing 10% of barium glass and 30% of DCPD particles functionalized with DEGDMA; 4. DCPD60% - experimental composite containing 60% of DCPD particles functionalized with DEGDMA; 5. Beautifil - GIOMER (Beautifil II, Shofu Dental Corporation); 6. Fuji IX - high viscosity glass ionomer (Fuji IX, GC Corporation); 7. Fuji II LC - resin-modified glass ionomer (Fuji II LC, GC Corporation). The specimens were polished again and then submitted to one of the two treatments: erosion only (n=10) or erosion plus toothbrushing abrasion (n=10). Erosion was performed by immersing the specimens in 0.3% citric acid solution (p~2.6), for 5 min, followed by 60 min exposure to artificial saliva. This procedure was repeated 4 times a day, for 5 days. Toothbrushing was performed with a slurry of a standard dentifrice (Colgate Total 12 Mint Clean; 1450 ppm F, as NaF), for 15 s (2 min total exposure time to the slurry), 2 times a day, 30 min after the first and last erosive challenges. At the end of cycling, enamel, dentin and restorative material surface loss (in ?m) were determined by optical profilometry. Data were analyzed by the Kruskal-Wallis and Tukey tests. The level of significance was 5%. In the erosion model, for enamel, both ionomeric cements presented lower surface loss than the Z350, although Fuji II LC did not differ significantly from Beautifil and DCPD30% groups. The other groups were no different from Z350 and from each other. For dentin, none of the groups were different from Z350, except for DCPD60%, which presented the highest surface loss. Both ionomeric cements presented lower loss than DCPD30%, Beautifil and DCPD60%. Regarding the restoration, the materials Z350, Beautifil, VB, DCPD30% showed minimal surface loss, with no differences between them. The ionomeric cements had the highest loss values, not differing from DCPD60%. In the erosion-abrasion model, for enamel, the lowest loss was observed for Fuji II LC, with no difference to Beautifil. The other groups showed no difference among them and from Beautifil. For dentin, the groups DCPD60%, Beautifil, Fuji II LC, Z350 and Fuji IX were no significant different and presented lower loss than VB. These five groups were also no different from DCPD30%, except Fuji IX. Regarding the restoration, the highest loss was observed for Fuji IX, with no difference from Fuji II LC and Beautifil. DCPD30%, Z350, VB and DCPD60% presented minimum values of surface loss, without differences between them. It was concluded that Fuji II LC ionomeric cement was the only material able to protect the enamel adjacent to the restoration against erosive and erosive/abrasive challenges, although it was one of the materials that was most susceptible to be wear off by both challenges. For dentin, no material exhibited a significant protective effect.
9

Efeito dos desafios erosivo ou erosivo/abrasivo sobre as estruturas dentárias adjacentes às restaurações realizadas com materiais contendo fluoreto ou cálcio / Effect of erosive and erosive/abrasive challenges on the dental hard tissues adjacent to restorations performed with materials containing fluoride or calcium

Ítallo Emídio Lira Viana 29 January 2018 (has links)
Esse estudo avaliou in vitro o efeito dos desafios erosivo ou erosivo/abrasivo sobre materiais restauradores contendo fluoreto ou cálcio e sobre as estruturas dentárias adjacentes às restaurações realizadas com esses materiais. Fragmentos de esmalte e de dentina bovinos (4 mm × 4 mm × 2 mm), foram incluídos em resina acrílica e planificados. Uma cavidade padrão com dimensões 1,2 mm × 4 mm × 1,5 mm foi preparada nos espécimes, e restaurada de acordo com o material a ser testado: 1. Z350 - resina composta (Filtek Z350, 3M ESPE); 2. VB - compósito experimental contendo apenas vidros de bário; 3. DCPD30% - compósito experimental contendo 10% de vidros de bário e 30% partículas de fosfato di-cálcio di-hidratado (DCPD) funcionalizadas com dimetacrilato de dietilenoglicol (DEGDMA); 4. DCPD60% - compósito experimental contendo 60% partículas de DCPD funcionalizadas com DEGDMA; 5. Beautifil - GIOMER (Beautifil II, Shofu Dental Corporation); 6. Fuji IX - cimento de ionômero de vidro convencional de alta viscosidade (Fuji IX, GC Corporation); 7. Fuji II LC - cimento de ionômero de vidro modificado por resina (Fuji II LC, GC Corporation). Na sequência, os espécimes foram polidos e submetidos a dois tipos de tratamentos: erosão somente (n=10) ou erosão mais abrasão por escovação (n=10). A erosão foi realizada pela imersão dos espécimes em ácido cítrico a 0,3% (pH~2,6) por 5 min, seguido de 60 min de imersão em saliva artificial. Esse procedimento foi repetido 4×/dia, por 5 dias. A escovação foi realizada com uma suspensão de dentifrício padrão (Colgate Total 12 Mint Clean; 1450 ppm F-, como NaF) por 15 s (2 min de exposição total a suspensão de dentifrício), 2×/dia, 30 min após o primeiro e o quarto desafios erosivos. Ao final da ciclagem, a perda superficial (em ?m) do esmalte, da dentina e dos materiais restauradores foi determinada com um perfilômetro ótico. Para cada modelo (erosão e erosão-abrasão), os dados de perda superficial de esmalte, dentina e restauração foram analisados de maneira independente. Os dados foram analisados pelos testes de Kruskal-Wallis e Tukey. O nível de significância utilizado foi de 5%. No modelo de erosão, para esmalte, ambos cimentos ionoméricos apresentaram menor perda superficial do que o compósito Z350, apesar de Fuji II LC não ter se diferenciado significativamente dos grupos Beautifil e DCPD30%. Os outros grupos não foram diferentes de Z350 nem entre si. Para dentina, nenhum dos grupos foi diferente de Z350, com exceção de DCPD60%, o qual apresentou a maior perda superficial. Ambos cimentos ionoméricos apresentaram menor perda do que DCPD30%, Beautifil e DCPD60%. Em relação à restauração, os materiais Z350, Beautifil, VB, DCPD30% apresentaram perda superficial mínima, sem diferenças entre eles. Os cimentos ionoméricos apresentaram os maiores valores de perda, não se diferenciando de DCPD60%. No modelo erosão-abrasão, para esmalte, a menor perda superficial foi observada em Fuji II LC, sem diferença da Beautifil. Os outros grupos não se diferenciaram entre si nem da Beautifil. Para dentina, os grupos DCPD60%, Beautifil, Fuji II LC, Z350 e Fuji IX não se diferenciaram e, apresentaram menor perda superficial do que VB. Os cinco grupos citados também não foram diferentes de DCPD30%, com exceção de Fuji IX. Em relação à restauração, a maior perda foi observada para Fuji IX, sem diferenças de Fuji II LC e Beautifil. DCPD30%, Z350, VB e DCPD60% apresentaram valores mínimos de perda superficial, sem diferenças entre si. Concluiu-se que o cimento ionomérico Fuji II LC foi único capaz de proteger o esmalte adjacente à restauração contra desafios erosivos e erosivos/abrasivos, apesar de ter sido um dos materiais mais susceptíveis ao desgaste por ambos desafios. Para dentina, nenhum material exibiu efeito protetor. / This in vitro study evaluated the effect of erosive or erosive/abrasive challenges on restorative materials containing fluoride and calcium, and on the dental hard tissues adjacent to restorations performed with these materials. Enamel and dentin specimens (4 mm × 4 mm × 2 mm), obtained from bovine incisors, were embedded in acrylic resin, flattened and polished. In the specimens, a standard cavity of 1,2 mm × 4 mm × 1,5 mm was prepared and restored with the following materials: 1. Z350 - Composite resin without actives, Filtek Z350 (3MESPE); 2. VB - experimental composite containing barium glass only; 3. DCPD30% - experimental composite containing 10% of barium glass and 30% of DCPD particles functionalized with DEGDMA; 4. DCPD60% - experimental composite containing 60% of DCPD particles functionalized with DEGDMA; 5. Beautifil - GIOMER (Beautifil II, Shofu Dental Corporation); 6. Fuji IX - high viscosity glass ionomer (Fuji IX, GC Corporation); 7. Fuji II LC - resin-modified glass ionomer (Fuji II LC, GC Corporation). The specimens were polished again and then submitted to one of the two treatments: erosion only (n=10) or erosion plus toothbrushing abrasion (n=10). Erosion was performed by immersing the specimens in 0.3% citric acid solution (p~2.6), for 5 min, followed by 60 min exposure to artificial saliva. This procedure was repeated 4 times a day, for 5 days. Toothbrushing was performed with a slurry of a standard dentifrice (Colgate Total 12 Mint Clean; 1450 ppm F, as NaF), for 15 s (2 min total exposure time to the slurry), 2 times a day, 30 min after the first and last erosive challenges. At the end of cycling, enamel, dentin and restorative material surface loss (in ?m) were determined by optical profilometry. Data were analyzed by the Kruskal-Wallis and Tukey tests. The level of significance was 5%. In the erosion model, for enamel, both ionomeric cements presented lower surface loss than the Z350, although Fuji II LC did not differ significantly from Beautifil and DCPD30% groups. The other groups were no different from Z350 and from each other. For dentin, none of the groups were different from Z350, except for DCPD60%, which presented the highest surface loss. Both ionomeric cements presented lower loss than DCPD30%, Beautifil and DCPD60%. Regarding the restoration, the materials Z350, Beautifil, VB, DCPD30% showed minimal surface loss, with no differences between them. The ionomeric cements had the highest loss values, not differing from DCPD60%. In the erosion-abrasion model, for enamel, the lowest loss was observed for Fuji II LC, with no difference to Beautifil. The other groups showed no difference among them and from Beautifil. For dentin, the groups DCPD60%, Beautifil, Fuji II LC, Z350 and Fuji IX were no significant different and presented lower loss than VB. These five groups were also no different from DCPD30%, except Fuji IX. Regarding the restoration, the highest loss was observed for Fuji IX, with no difference from Fuji II LC and Beautifil. DCPD30%, Z350, VB and DCPD60% presented minimum values of surface loss, without differences between them. It was concluded that Fuji II LC ionomeric cement was the only material able to protect the enamel adjacent to the restoration against erosive and erosive/abrasive challenges, although it was one of the materials that was most susceptible to be wear off by both challenges. For dentin, no material exhibited a significant protective effect.
10

Feeding biology of common and blue duiker

Kigozi, Frederick January 2001 (has links)
The blue duiker, Philantomba monticola and common or grey duiker, Sylvicapra grimmia represent two of the three duiker genera as well as two of the three species occurring in Southern Africa. The two species have not been adequately studied in their habitats within the Eastern Cape Province of South Africa, and this thesis centres around their biology with focus on diet and dental microwear. Faecal analysis was used to study the diet of blue duiker at Salem in the Albany district, and of common duiker on two farms, one a predominantly cattle farm at Kasouga and the other a farm for cultivation of chicory at Grants valley, both in the Bathurst district. The validity of faecal analysis was reviewed, and its applicability to blue and common duiker assessed. The method was appropriate for diet analysis of both species, as the common duiker is shy and secretive and the blue duiker is a rare and protected species which does not habituate readily. Results showed that the blue duiker was mainly folivorous with a seasonally stable diet of 79 percent dicot foliage and only 17 percent fruit. Common duiker diet at both study sites comprised mostly dicot foliage, with only two monocotyledonous plant species. Twenty-seven and nineteen plant species were identified in the diets of common duiker at Kasouga and Grants valley respectively and the annual percentage occurrences of dicot foliage in the diets were about 99 percent at both study sites. The predominantly browsing common duiker, therefore offered negligible competition for food resources to the grazing cattle on Kasouga farm. Both blue and common duiker fed selectively, with approximately one third of the total number of plant species identified in their diets providing at least 50 percent of the food eaten annually. Ehretia rigida was the most important plant species in the diets of both duiker species. Chicory, Chichorium intybus provided more than one third (35.6 percent) of the winter diet and a substantial proportion (14.4 percent) of the spring diet of common duiker at Grants valley, thereby confirming earlier reports of this species feeding on chicory and other cultivated crops. The diet of common duiker at Kasouga did not vary seasonally but that of common duiker at Grants valley did vary and this was attributed to utilisation of chicory. Results from the dental microwear analyses did not show any significant differences in dental microwear between blue and common duiker, but supported and confirmed that the two were browsing species, characterised by many pits and few scratches on their dental surfaces. A high incidence of pits was found on the dental surfaces of both duiker species, and was attributed to utilisation of fruit in the diet.

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