Made available in DSpace on 2014-10-09T12:34:53Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:08:10Z (GMT). No. of bitstreams: 0 / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / A detecção de lesões cariosas nos estágios iniciais possibilita a escolha de tratamentos baseados na preservação da estrutura dental. Dessa forma, a utilização de exames capazes de diagnosticar precocemente essas lesões, como a Tomografia por Coerência Óptica (OCT Optical Coherence Tomography) é adequada. Assim, o objetivo do trabalho foi avaliar a capacidade da OCT em quantificar os estágios de desmineralização do esmalte durante o desenvolvimento de lesões simuladas de cárie, tendo como padrão de referência o teste de microdureza seccional. Foram utilizados 53 dentes terceiros molares hígidos, os quais tiveram as coroas seccionadas para obtenção de 210 amostras. Para avaliar as possíveis alterações sofridas por cada amostra, essas foram examinadas através da técnica de OCT no início do experimento e novamente examinadas após o término do período de ciclagem estabelecido para cada grupo, utilizando os coeficientes de atenuação óptica total e o cálculo de área em gráficos de intensidade de sinal de OCT, como parâmetros de análise. Posteriormente, as amostras foram submetidas a testes de microdureza seccional. A diferença entre os coeficientes de atenuação óptica obtidos antes e depois da ciclagem de pH apresentou elevado grau de correlação com os resultados de microdureza seccional. Por meio da análise das áreas provenientes de gráficos de intensidade de sinal de OCT e microdureza Knoop, ambos em função da profundidade, foi observada relação de linearidade entre os resultados e elevada correlação entre as técnicas avaliadas (ρ = 0,99). De acordo com os resultados, a técnica de OCT foi capaz de detectar diferentes graus de desmineralização do esmalte dental humano em lesões simuladas de cárie. / Dissertação (Mestrado) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP / FAPESP:10/03123-8

O estudo objetivou avaliar a resistência da união de sistemas adesivos aplicados ao esmalte, bem como a morfologia do substrato condicionado e a qualidade da interface de união formada. Após o esmalte das superfícies lisas de molares receberem profilaxia com pedrapomes, abrasão por lixa ou desgaste por ponta de diamante, foram aplicados Scotchbond Multi-Purpose Plus (SBMP), Single Bond (SB), Clearfil SE Bond (CSE); OptiBond Solo Plus Self-Etch (OP) e Tyrian Self Priming Etching (TY). Os semidentes ?restaurados? com resina Filtek Z250 foram armazenados em água deionizada (24h/37°C), secionados no formato de paralelogramo (área transversal aproximada de 0,8 mm2), aleatorizados em grupos (24h, 6 e 12 meses de armazenagem), e testados em microtração (0,5mm/min). Os valores médios de resistência da união (MPa) foram tratados por métodos de ANOVA e Tukey. Os resultados não mostraram diferenças significativas para os fatores Tratamento, Armazenagem, nem para as interações..Porém, houve diferença significante para o fator Adesivo (p<0,05). Os padrões morfológicos do esmalte obtidos após o uso do agente condicionante dos sistemas SBMP e SB não foram influenciados pelo Tratamento. Os fatores Adesivo e Tratamento influenciaram no padrão dos sistemas CSE, OP e TY. Não foram observadas fendas nas interfaces dos sistemas SBMP e SB, independente dos outros fatores. .Os sistemas OP e TY mostraram fendas em todas as condições, e o CSE após 12 meses no esmalte abrasionado por lixa. Com base nos resultados, conclui-se que o desempenho dos sistemas adesivos estudados está vinculado mais às características dos produtos do que ao tratamento realizado no esmalte ou armazenagem. / This study aimed to evaluate the resin-enamel bond strength, the etching pattern and the bonded interfaces provided by self-etch systems by means of scanning electron microscopy. The following adhesives systems (Scotchbond Multi-Purpose Plus [SBMP], Single Bond [SB], Clearfil SE Bond [CSE]; OptiBond Solo Plus Self-Etch [OP] or Tyrian Self Priming Etching [TY] were applied to sound enamel (after tooth prophylaxis), SiC paper or diamond bur-treated enamel. Resin composite buil-dups (Filtek Z250) were bonded to the enamel surfaces. After storage in water (24h/37°C), the bonded samples were sectioned into beams (0.8mm2), randomly assigned into subgroups (24h, 6 and 12 months) and subjected to microtensile bond strength test (0.5 mm/min). The data was analyzed by ANOVA and Tukey?s test. The main factors enamel Treatment and Storage as well as the interactions were not statistically significant. Significant differences were observed only for the main factor Adhesive (p<0.05). The Treatment did not affect the etching pattern of SBMP and SB; for CSE, OP and TY the morphology varied with the Treatment and Adhesive system. Gaps were not observed in the interfaces bonded with SBMP and SB, regardless of the Storage and Treatment. The adhesive CSE showed gaps after 12 months of storage for SiC paper, while this finding was observed for OP and TY in all conditions. Based on the results of the present investigation, it was concluded that the performance of some adhesive systems is influenced by the material´s composition instead of surface treatment or storage.

Magister Chirurgiae Dentium - MChD / The purpose of this study was to evaluate in vitro, the tensile bond strengths of some conventional and light cured resins, to study the effects of etchants on polished and ground enamel using the scanning electron microscope, and to the resin/etched enamel examlne electron interface by scanning microscopy This study was divided into: 1) laboratory tensile bond strength study of 'four composite resin materials. 2) a scanning electron microscopic study of the effect of four etchants on enamel. 3) the S.E.M. examination of the interfacial zone after the application of a demineralizing agent. The tensile bond strength study consisted of testing the bond strengths of two macrofilled and two microfilled resins in common use. These resins were applied directly to the etched enamel surfaces of extracted human teeth by utilizing newly developed perpex stubs which allowed a uniform surface area and for light curing of the resin. In this laboratory study the extracted teeth and the composite filled stubs were stressed to failure of the material bond to tooth in an Instron Machine. Bond strengths were recorded and tabulated in Newtons/mm2. The application of statistical analysis by Analysis of Variance and Duncans Multiple Range Test showed that there was a significant difference in the bond strengths of some of the four materials. The scanning electron microscope study consisted of an examination of etched enamel, either polished or ground using the etchants supplied by the two manufacturers i.e. 3 M Dental Company and J&J Dental Company. The interfacial zones of the resin/tooth interface systems were examined, using the two macrofilled and the two microfilled resijs in the stUdY.! Differences were found to exis.t at this zone.

Prairie (Microtus ochrogaster) and woodland (Microtus pinetorum) voles, which exhibit distinctly different ecological preferences (grassland versus forest), commonly co-occur in paleontological deposits in eastern North America. Despite their ecological differences, their molar morphology is similar. Assuming that those ecologic differences occurred in the past, differentiation of these two taxa is important for paleoenvironmental reconstruction. A sample of 51 lower first molars from living populations were viewed via scanning electron microscope to qualify and quantify schmelzmuster (enamel microstructure) to species-specific standards applicable to the fossil record. The most obvious differences between schmelzmuster of the two taxa are the relatively thicker bands of radial enamel on the leading edges of triangles of M. ochrogaster, as well as the consistent retention of tangential or primitive tangential enamel on the trailing edges and posterior enamel band of the posterior loop of M. pinetorum. Discriminant analysis of landmark data from the same 51 specimens established morphological boundaries for these taxa and successfully separated the recent m1s of M. ochrogaster from those of M. pinetorum. To test identification confidence from previous work, and to add an independent means of identification for future work (at any site), both techniques were applied to a sample of three-closed triangle (“M. ochrogaster” type) m1s from the late Pleistocene Wapsipinicon Local Fauna of Jones County, Iowa. Identifications of the specimens from the Wapsipinicon l.f. based on schmelzmuster and morphometric analysis are consistent with those reached using traditional morphology. Such methods serve as independent “check” of traditional (qualitative) identification, highlight new species-level characters, and quantify previously described features, for discrimination of these taxa.

Indiana University-Purdue University Indianapolis (IUPUI) / The purpose of this investigation was to study the incidence of enamel pitting and gingival fibromas in patients with tuberous sclerosis complex (TSC) and relate these findings to other physical findings of TSC, to sporadic and familial disease, and to specific TSC2 mutations. Methods: A total of 104 patients between 1 and 51 years of age were examined for enamel pits and gingival fibromas. All study subjects had a definitive diagnosis of TSC and were participants in a related study that provided results from MRI scans of the brain, echocardiography, renal ultrasound, neuropsychological assessments, and retinal examinations. Blood samples were obtained from each participant for DNA extraction and subsequent TSC mutational analysis. Results: Enamel pitting was seen in 29% of patients between 1 and 6 years of age, in 90% between 6 and 13 years of age, and in 100% of patients in the permanent 113 dentition. The majority of the pits were pinpoint sized and primarily affected the maxillary anterior arch. The maxillary central incisor was the most often affected permanent tooth and the maxillary canine was the most often affected primary tooth. Gingival fibromas were apparent in 47% of subjects in the mixed dentition and in 70% of subjects in the permanent dentition. Only one patient out of 31 in the primary dentition had a gingival fibroma. The majority of fibromas affected the interdental papilla of the maxillary anterior arch. There were few significant findings relating the degree and/or severity of enamel pitting and/or gingival fibromas to other physical findings of TSC. Enamel pitting in primary as well as permanent teeth were found to be strongly related to the presence of facial angiofibromas and a somewhat weaker association was seen with cardiac arrhythmias. Gingival fibromas were strongly related to the presence of facial angiofibromas and more weakly related to retinal lesions. There were no distinctions apparent between oral findings in sporadic and familial TSC nor were there any genotype-phenotype correlations between oral findings and TSC2 mutations. Conclusion: The combination of enamel pitting and gingival fibromas, as minor features of TSC, should raise the suspicion level regarding tuberous sclerosis as a diagnosis. Both are important minor features frequently seen which may help in establishing a definitive diagnosis. Scanning the dentition and gingiva is noninvasive, is inexpensive, and should be included in evaluating all patients suspect of a diagnosis of tuberous sclerosis.

Indiana University-Purdue University Indianapolis (IUPUI)

Indiana University-Purdue University Indianapolis (IUPUI) / Many factors may affect orthodontic bond strength study results. An important variant to consider is the bonding surface contour. Contour alters the proximity of adherent surfaces, the surface area available for adhesion, and the stress distribution. It was the purpose of this study to determine if bracket base or enamel contour affect in vitro bond strengths. Orthos Mini-Diamond (ORMCO Corp.) .0 018" slot central incisor brackets with flattened or unaltered curved bases were bonded (System 1 + self cure resin cement by ORMCO, Corp.) to unaltered and flattened bovine central incisors. Bond strengths were determined by debonding on a Bionix 858 (MTS System Corp.) testing machine. The results showed that unaltered bracket bases bonded on unaltered enamel surfaces (the closest approximation to a clinical situation) had the significantly (p< 0.0002) lowest tensile bond strength among the three combinations. The adhesive remnant index evaluation demonstrated that unaltered bracket base/ unaltered enamel surface (Group II) had significantly higher ARI (less adhesive remaining on enamel) than any of the other groups. A negative correlation between ARI scores and mean bond strength was found. There was not a significant difference between flattened bracket base / flattened enamel surface (Group I) and unaltered bracket base/ flattened enamel surface. The results suggest that the surface convexity and texture of enamel are important variables that can affect bond strength tests results. Standardization of testing protocols and control of the different variables that can affect bond strength are important factors in the testing of orthodontic brackets.

Indiana University-Purdue University Indianapolis (IUPUI) / Background: The importance of fluoride in the prevention of dental caries has been well documented in the literature, as it inhibits demineralization of the tooth structure and enhances remineralization. One of the major public health policies to prevent caries is to provide the population with an adequate amount of fluoride through community water fluoridation. Nowadays many people drink bottled water instead of tap water due to its easy access, convenience, and low cost. Besides fluoride, other minerals present in tap and bottled water, such as calcium and magnesium, are also important in decreasing dental caries prevalence. However, our knowledge of the role of bottled water in caries prevention and especially when combined with fluoride toothpaste usage is still poor. Objectives: The aim of this in-vitro study was to evaluate the effects of some bottled waters on fluoride toothpaste efficacy in enhancing caries lesion remineralization. Methodology: Early caries lesions were created in bovine enamel specimens and stratified into treatment groups based on Vickers surface microhardness (VHN). The present study followed a two (fluoride and fluoride-free toothpaste) by five (four bottled waters and tap water) factorial design. The treatment groups were bottled water with the following attributes: a) 309.9 ppm Ca/1.20 ppm F; b) 118.4 ppm Ca/0.16 ppm F; c) 1.00 ppm Ca/1.01 ppm F; d) 0.1 ppm Ca/0.04 ppm F, and tap water (48.7 ppm Ca/0.7 ppm F). The five water groups were paired either with 1100 ppm fluoride or fluoride-free toothpaste, yielding 10 groups. Specimens were pH-cycled for 10 days with the daily regimen comprised of twice daily toothpaste slurry, with four exposures to water in between. VHN was measured, again, and the difference calculated (ΔVHN). Data were analyzed using two-way ANOVA at a 5-percent significance level. Results: The two-way interaction between water and toothpaste was significant (p < 0.001). All groups except fluoride-free toothpaste/bottled water with 0.1 ppm Ca/0.04 ppm F (p = 0.411) had significant increases in VHN after pH cycling (p ≤ 0.023). Fluoridated toothpaste resulted in a higher rate of remineralization compared to fluoridefree toothpaste (all p < 0.001). Bottled water with 1.20 ppm F/309.9 ppm Ca exhibited the greatest extent of remineralization within fluoride toothpaste groups (p < 0.001) and higher remineralization than lower fluoride water in fluoride-free toothpaste groups (p ≤ 0.006). Within the fluoridated toothpaste group, tap water exhibited significantly less remineralization compared to all bottled waters (all p < 0.001). Conclusion: Within the limitation of this study, bottled water with higher fluoride and calcium concentrations might improve fluoridated toothpaste efficacy by enhancing remineralization of early enamel caries-like lesions.

The tribosphenic molar is an ancestral type of mammalian teeth and a phy- lotypic stage of the mammalian dental evolution. Yet, in contrast to derived teeth types, its enamel microarchitecture attracted only little attention and the information on that subject is often restricted to statements suggesting a simple homogenous arrangement of a primitive radial prismatic enamel. The present paper tests this prediction with aid of comparative study of eight model species representing the orders Chiroptera, Afrosoricida, Eulipotyphla (Erinaceomorpha) and Eulipotyphla (Soricomorpha). Spe- cial attention was paid to shrews (Soricidae), the group with most derived tribosphenic dentition among extant insectivores. The detailed electron microscopic (SEM) analysis of standardized cross sections over essential structural elements of tribosphenic molars (in shrews supplemented with sections of the lower incisor, the most derived tooth of the dentition) was a basic source of information. The results demonstrated common arrangements related to tribosphenic design (he- terotopy of enamel thickness, radial prismatic enamels as primary product of ameloge- netic activity), yet, an unexpectedly broad span of variation in state of further variables was discovered at the same time. The taxon-specific arrangements and...

Thesis (M.S.)--West Virginia University, 2001. / Title from document title page. Document formatted into pages; contains viii, 97 p. : ill. Includes abstract. Includes bibliographical references (p. 75-83).