Dentre as estratégias de tratamento de lesões incipientes de cárie, no estágio de mancha branca ativa, o infiltrante resinoso tem sido empregado, preenchendo os poros do esmalte e impedindo a sua progressão. O objetivo deste trabalho foi avaliar o efeito do infiltrante de cárie (Icon®) sobre lesões cariosas artificiais produzidas por diferentes protocolos e a eficiência deste tratamento após novo desafio ácido por modelos experimentais in vitro e in situ, utilizando a microdureza de superfície (MS) e longitudinal (ML). Na fase in vitro, lesões cariosas artificiais foram produzidas em 45 espécimes de esmalte bovino (6x4mm) através de três diferentes protocolos (ciclagem DES-RE, gel MC e solução MHDP). Os espécimes foram tratados com o infiltrante e submetidos a novo desafio ácido por ciclagem DES-RE. Este delineamento resultou em 4 condições em um mesmo espécime: hígida (H), após a desmineralização (D), após o tratamento com o infiltrante (I) e após o novo desafio ácido (N). Na fase in situ, 15 voluntários usaram dispositivos palatinos contendo dois espécimes por 14 dias, induzindo a lesão por meio de gotejamento de solução de sacarose 8x/dia. Nas duas fases, a MS e ML foram avaliadas em todas as condições dos espécimes até 220&#x3BC;m. Os dados foram coletados e processados pela porcentagem da diferença com os valores iniciais da condição hígida para serem analisados estatisticamente de acordo com ANOVA (medidas repetidas) e teste de Tukey (p<0,05). No estudo in vitro e in situ todos os protocolos de desmineralização foram capazes de produzir lesões de cárie de subsuperfície. Todos os protocolos in vitro promoveram perda de dureza de superfície maior que 75%, enquanto o protocolo in situ promoveu quase 40%. Há uma redução da perda de dureza à medida que a profundidade aumenta em todos os casos, sendo as particularidades mais observadas até 50 &#x3BC;m. O infiltrante avaliado em todas as condições foi capaz de re-equilibrar parcialmente a dureza interna, entretanto sua resistência e efeito após o novo desafio ácido apresentou-se limitado. / Among the strategies for early caries lesions treatment as active white spot, the resin infiltrant has been employed filling the enamel pores and preventing their progression. The aim of this study was to evaluate the effect of caries infiltrant (Icon®) on artificial carious lesions produced by different protocols, and the efficiency of this treatment after new challenge acid by in vitro and in situ experimental models, using the surface microhardness (SH) and cross-sectional microhardness (CSH). In the in vitro phase, artificial carious lesions were performed on 45 enamel bovine specimens (6x4mm) by three different protocols (DE-RE cycling, MC gel and MHDP solution). The specimens were treated with the infiltrant and subjected to a new challenge by DE-RE cycling. This design resulted in four conditions at the same specimen: sound (S), after demineralization (D), after the treatment with infiltrant (I) and after the new acid challenge (N). In the in situ phase, 15 volunteers wore intraoral appliances containing two specimens for 14 days, inducing the lesion formation by sucrose solution dripping 8x/day. In both models, SH and CSH were evaluated in all conditions of the specimens up to 220&#x3BC;m. Data were collected and processed as percentage from the difference to each condition compared to sound stage to be statistically analyzed with ANOVA (repeated measures) and Tukey test (p <0.05). For all tested conditions, demineralization protocols were able to produce subsurface carious lesions. All in vitro protocols promoted hardness loss higher than 75% while in situ protocol promoted almost 40%. There is a reduction in the hardness loss as the depth increases, in which the main differences can be noticed up to 50&#x3BC;m. The infiltrant evaluated in all conditions was able to partially re-balance the internal hardness, however its strength and effect after the new challenge acid had been limited.

Apesar dos conhecimentos já existentes sobre o xilitol, seu efeito no desenvolvimento da cárie dentária ainda requer maiores esclarecimentos. Assim, este estudo in situ randomizado, duplo-cego e cruzado teve como objetivo determinar o efeito de xilitol em pastilhas na composição do biofilme dental e nos processos de desmineralização e remineralização do esmalte, comparado a um controle com pastilhas contendo sorbitol. Em duas fases de 14 dias, 11 voluntários utilizaram dispositivos palatinos com seis blocos de esmalte humano (três hígidos para avaliação da desmineralização + três previamente desmineralizados para avaliação da remineralização) com dureza de superfície conhecida. Sacarose 20% foi gotejada oito vezes ao dia apenas sobre os blocos hígidos. Cinco minutos após cada gotejamento, os dispositivos eram recolocados na boca e os voluntários chupavam pastilha com xilitol 88,3% ou sorbitol 84,5%. A utilização das pastilhas iniciou-se uma semana antes de cada fase experimental. Foi usado dentifrício sem flúor. Ao final de cada fase, o biofilme formado sobre os blocos foi coletado e dividido para análises microbiológica e bioquímica, e os fragmentos de esmalte foram analisados quanto a variação de dureza de superfície antes e após o experimento. A porcentagem de perda de dureza de superfície dos blocos de esmalte do grupo do xilitol apresentou uma tendência a ser menor do que aquela observada no grupo do sorbitol, embora a diferença não tenha sido significante (p= 0,066; ANOVA). Também não houve diferença estatisticamente significante entre os grupos em relação à porcentagem de ganho de dureza de superfície e à maioria dos parâmetros bioquímicos do biofilme. As médias das concentrações de fósforo inorgânico e de polissacarídeo intracelular no biofilme no experimento de desmineralização foram significantemente menores (p< 0,001 e p= 0,007) no grupo do sorbitol. As porcentagens de estreptococos do grupo mutans (SM) em relação ao total de estreptococos (S) (p= 0,037) no experimento de desmineralização, assim como as contagens de SM (p= 0,035) e lactobacilos (p= 0,048), e as porcentagens de SM em relação ao total de microrganismos (p= 0,035) e em relação a S (p= 0,017) no experimento de remineralização foram significantemente menores no biofilme do grupo do xilitol. Os demais parâmetros microbiológicos não foram influenciados de maneira significante pelos tratamentos. O uso de pastilhas com xilitol por curtos períodos de tempo não apresentou vantagem nem em diminuir a desmineralização nem em favorecer a remineralização do esmalte em comparação ao uso de pastilhas com sorbitol, mas alterou a ecologia bacteriana do biofilme, reduzindo as contagens e as porcentagens de importantes grupos de microrganismos cariogênicos. / In spite of the existing knowledge about xylitol, its effect on the development of dental caries is still a subject that requires further clarifications. Thus, this randomized, double-blind, crossover in situ study aimed at assessing the effect of xylitol mints in the dental biofilm composition and in the processes of enamel demineralization and remineralization, in comparison to a control group using sorbitol mints. During the two phases of 14 days, 11 volunteers wore palatal appliances with six human enamel blocks (three intact ones for evaluation of demineralization and three demineralized ones for the evaluation of remineralization) of known superficial hardness. A solution of 20% sucrose was dripped only on the intact enamel blocks eight times per day. Five minutes after each dripping, the appliances were placed back inside the mouth and the volunteers took either an 88.3% xylitol mint or an 84.5% sorbitol mint. Both types of mints started being used by the volunteers one week before each experimental phase. Non-fluoridated toothpaste was used. At the end of each phase, the biofilm formed over the blocks was collected and divided for microbiological and biochemical analysis and the enamel fragments were evaluated in relation to surface hardness variation before and after the experiment. The percentage of surface hardness loss of the enamel blocks in the xylitol group tended to be lower than in those of the sorbitol group although this difference was not significant (p= 0.066; ANOVA). Moreover, there were no statistically significant differences between the study groups regarding the percentage of surface hardness gain or regarding the biochemical parameters of the biofilm. The average concentrations of inorganic phosphorus and of intracellular polysaccharides in the biofilm for the demineralization experiment were significantly lower (p< 0.001 and p= 0.007) in the sorbitol group. The following results were significantly lower in the xylitol group biofilm: percentages of mutans streptococci (SM) in relation to the total number of streptococci (S) (p= 0.037) in the demineralization experiment; SM (p= 0.035) and lactobacilli (p= 0.048) count; and the percentages of SM in relation to the total number of microorganisms (p= 0.035) and in relation to S (p= 0.017) in the remineralization experiment. Other microbiological parameters were not significantly influenced by the treatments. Taking xylitol mints during short periods of time did not show advantages regarding the decrease of enamel demineralization or the promotion of enamel remineralization when compared to taking sorbitol mints. However, it did expressively alter the bacterial ecology of the biofilm, reducing the percentage and count of important groups of cariogenic microorganisms.

Orientador: Carlos Rocha Gomes Torres / Coorientadora: Lívia Maria Andaló Tenuta / Banca: Natália Cortez Gutierrez / Banca: Maria Filomena Rocha Lima Huhtala / Resumo: O estudo avaliou se os efeitos deletérios do clareamento no esmalte dental podem ser minimizados pela adição de sais de cálcio e/ou fósforo em variadas concentrações, na formulação do agente clareador, tornando-o progressivamente mais saturado em relação ao conteúdo mineral do esmalte.Inicialmente foi determinada a concentração dos elementos cálcio (Ca) e fósforo (P)no agente clareador,provenientes da dissolução do esmalte dental pelo tratamento até atingir seu ponto de saturação. Para tal amostras de esmalte foram trituradas e expostas ao peróxido de hidrogênio (PH) à 35% em pH7, até que um equilíbrio mineral fosse obtido. A concentração mineral na solução foi determinada através dos métodos de ICP-AES. A seguir o coeficiente de solubilidade de diversos sais de cálcio e fósforo em PH à 35%foi determinado. Aquele mais solúvel para cada elemento foi utilizado para a formulação dos agentes clareadores.Foram preparados 120 espécimes a partir da face vestibular de dentes incisivos bovinos, em formato circular com 4 mm de diâmetro, padronizando-se a espessura de esmalte e dentina em 1mm cada, embutidos em resina branca. Os espécimes foram enumerados e imersos em saliva artificial por 15 dias. Após esse período, foram realizadas leituras iniciais da microdureza Knoop do esmalte empregando um microdurômetro (FM-700, Future-Tech, Tóquio, Japão), da rugosidade superficial em um perfilômetro de contato (MarSurf GD 25, Mahr, Goettingen, Alemanha) e da cor das amostras utilizando espectr... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract : The study evaluated whether the deleterious effects of bleaching on tooth enamel can be minimized by adding calcium and / or phosphorus salts at varying concentrations in the bleaching agent formulation, making it progressively more saturated relative to the enamel mineral content. Initially, the concentration of calcium (Ca) and phosphorus (P) elements in the bleaching agent were determined, resulting from the dissolution of dental enamel by the treatment until reaching its saturation point. For such enamel samples were crushed and exposed to hydrogen peroxide (PH) at 35% at pH7, until a mineral balance was obtained. The mineral concentration in the solution was determined by ICP-AES methods. Then the solubility coefficient of several calcium and phosphorus salts in PH at 35% was determined. The most soluble for each element was used for the bleaching agent formulation. 120 specimens were prepared from the vestibular face of bovine incisor teeth, in circular format with 4 mm diameter, and the thickness of enamel and dentin was standardized in 1 mm each, embedded in white resin. The specimens were enumerated and immersed in artificial saliva for 15 days. After that, initial Knoop enamel microhardness measurements were performed using a microdurometer (FM700, Future-Tech, Tokyo, Japan), of surface roughness in a contact profilometer (MarSurf GD 25, Mahr, Goettingen, Germany) and of the samples using a colorimetric reflectance spectrophotometer (CM 2600d - Konica Minolta, Osaka, Japan). All experimental groups were cleared with pH solutions at 35% (w / w) adjusted for pH 7. The specimens were divided into 6 groups according to the amount of calcium and phosphorus added in each bleaching solution, based on saturation at relation to HA, they are: CN (negative control) - the specimens were treated with ultra pure water; CP (positive control) - the specimens were ...(Complete abstract click electronic access below) / Mestre

Purpose: This in vitro study evaluated the effectiveness of using a 37% phosphoric acid liquid etchant along with MI Paste Plus™ powered technology compared to using MI Paste Plus™ alone or to an artificially created saliva solution in decreasing the demineralization and enhancing the remineralization of artificial carious lesions created on extracted human teeth. The teeth were analyzed and compared using polarized light microscopy, quantitative light-induced fluorescence, and digital photography. Materials and Methods: One hundred three recently extracted non-carious human third molar teeth without observable white-spot lesions, decalcification, or dental fluorosis were selected for this twelve day study and randomly divided into four treatment groups as follows: Group 1 (Control) - Artificial saliva solution (27 teeth) Group 2 (MIP) - MI Paste Plus™ application for 30 minutes daily for 12 days (26 teeth) Group 3 (15MIP) - 15 second etch every third day and MI Paste Plus™ application for 30 minutes daily for 12 days (25 teeth) Group 4 (1MIP) - 1 minute etch on day one ONLY and application of MI Paste Plus™ for 30 minutes daily for 12 days (25 teeth). Results: Results of one<–>way ANOVA revealed there was a significant effect for the type of treatment on the lesion depth (p = 0.0027). The post-hoc Tukey-Kramer's test indicated there was a statistically significant difference between the two groups (15MIP and 1MIP) that incorporated an acid etch in combination with MI Paste Plus™ and the group with exposure to MI Paste Plus™ alone (MIP). In addition, results of one<–>way ANOVA showed that there was no statistically significant effect for type of treatment on the change in fluorescence (p = 0.1417) or the change in density (p = 0.1934). Conclusions: The results of the present study revealed there was a significant effect for the type of treatment on the lesion depth (p = 0.0027). However, the only significant difference found was between the two groups (15MIP and 1MIP) that incorporated an acid etch in combination with MI Paste Plus™ and the group with exposure to MI Paste Plus™ alone (MIP). Thus, daily applications of MI Paste Plus™, with or without an acid etch, did not produce a statistically significant difference in mean lesion depth when compared to the control (artificial saliva group). In addition, the results of the present study showed that there was no statistically significant effect for type of treatment on the change in fluorescence (p = 0.1417) or the change in density (p = 0.1934). Further research is needed to evaluate MI Paste Plus™ capability in prevention of demineralization and/or enhancement of remineralization by conducting randomized clinical trials.

Orientador: Sérgio Eduardo de Paiva Gonçalves / Banca: Ricardo Scarparo Navarro / Banca: Taciana Marco Ferraz Caneppele / Resumo: O objetivo deste estudo foi avaliar a eficácia de diferentes parâmetros de energia do Nd:YAG laser, associados ou não a um fotoabsorvedor na redução da desmineralização por cárie artificial, sobre a superfície de esmalte dental. De coroas de incisivos bovinos foram obtidos 80 espécimes circulares com 6 mm de diâmetro e 2 mm de altura (1 mm de esmalte e 1 mm de dentina), o esmalte foi polido com lixas de carbeto de silício. Em cada espécime foi delimitada uma metade na qual o esmalte ficou exposto. As amostras foram avaliadas em Microdurômetro e FTIR para verificação inicial, e distribuídas de forma aleatória em oito grupos (n=10), que receberam os seguintes tratamentos de superfície sobre o esmalte: G1 (controle negativo): não recebeu tratamento de superfície; G2 (controle positivo): aplicação tópica de fluorfosfato acidulado 1,23% gel por 4 min; G3 (Nd:YAG 60 mJ / pulso, 10Hz, 48 J/cm2, não contato); G4 (fotoabsorvedor + Nd:YAG 60 mJ); G5 (Nd:YAG 80 mJ / pulso, 10Hz, 64 J/cm2, não contato); G6 (fotoabsorvedor + Nd:YAG 80 mJ); G7 (Nd:YAG 100 mJ / pulso, 10Hz, 80 J/cm2, não contato); G8 (fotoabsorvedor + Nd:YAG 100 mJ). Após os tratamentos as amostras foram submetidas ao ciclo de des-remineralização para indução artificial de cárie, sendo então avaliadas em Interferômetro de luz branca, Microdurômetro e FTIR. Os resultados de microdureza foram submetidos à Análise de variância (ANOVA) sob 2 fatores (laser e fotoabsorvedor); ao teste de Tukey e ao teste de Dunnett, com nível de... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract : The aim of this study was to evaluate the effectiveness of different energy parameters of the Nd:YAG laser, associated or not to a photoabsorber in the reduction of demineralization by artificial caries, on the surface of dental enamel. From the crowns of bovine incisors, 80 circular specimens with 6 mm diameter and 2 mm height (1 mm of enamel and 1 mm of dentin) were obtained, the enamel was polished with silicon carbide sandpapers. In each specimen surface was delimited a half in which the enamel was exposed. The samples were evaluated in Microdurometer and FTIR for initial verification, and randomly distributed in eight groups (n = 10), which received the following surface treatments on the enamel: G1 (negative control): no surface treatment; G2 (positive control): topical application of acidulated fluorophosphate 1.23% gel for 4 min; G3 (Nd:YAG 60 mJ / pulse, 10 Hz, 48 J / cm2, non-contact); G4 (photoabsorber + Nd:YAG 60 mJ); G5 (Nd:YAG 80 mJ / pulse, 10 Hz, 64 J / cm2, non-contact); G6 (photoabsorber + Nd:YAG 80 mJ); G7 (Nd: YAG 100 mJ / pulse, 10 Hz, 80 J / cm2, non-contact); G8 (photoabsorber + Nd:YAG 100 mJ). After the treatments, the samples were submitted to the deremineralization cycle for artificial induction of caries, and were then evaluated in White Light Interferometer, Microdurometer and FTIR. The microhardness results were submitted to Analysis of Variance (ANOVA) under 2 factors (laser and photoabsorber); to the Tukey test and the Dunnett test, with a significance level of 5% ( = 0.05). Statistically significant differences were obtained in the photoabsorber factor individually and in the interaction between the laser and photoabsorber factors. There was a lower percentage of microhardness loss in the photoabsorber groups compared to the non-photoabsorber groups and in the G8 group...(Complete abstract click electronic access below) / Mestre

Pioneering work performed by Rosalind Franklin over half a century ago provided the first structural models of two distinct carbon types: those that become graphitic during carbonization at high temperatures, and those that do not. Moreover it is known that certain properties of carbonaceous materials including combustion, surface area, electrical resistivity, and catalytic properties are influenced by mineral impurities. The nature of this division in biocarbon structure and the known effects of minerals on carbon properties have led to this work; three principal topics were addressed; (1) the investigation of the solid state structure of biocarbons derived from various biomass feedstocks, (2) the removal of inorganic minerals from biomass, and (3) the investigation of biocarbon electronic structure subsequent to doping with select inorganic minerals. Charcoals and carbonized charcoals (i.e. biocarbons) were prepared from a wide variety of biomass substrates, including pure sugars containing 5- and 6-membered rings with furanose and pyranose configurations, lignin, agricultural residues (corncob and nut shells) and a hard wood. These biocarbons were subject to proximate and elemental analysis, gas sorption analysis, and analysis by ICP-MS, SEM, XRD, ESR, 13C CPMAS NMR, and MALDI-TOF MS. All the carbonized charcoals contained oxygen heteroatoms, had high surface areas, and were excellent conductors of electricity. Doping the biocarbon with boron or phosphorus resulted in a slight improvement in its electrical conductivity. The XRD analysis indicated that the carbonized charcoals possess an aromaticity of about 71% that results from graphite crystallites with an average size of about 20 . The NMR analysis confirmed the highly aromatic content of the carbonized charcoals. The ESR signals indicated two major types of carbon-centered organic radicals. A number of techniques employed highlighted differences between carbonized charcoals and synthetic graphite but none more so than MALDI-TOF spectrometry. The biocarbons contained readily desorbed discrete ions with m/z values of 701, 685, 465, 453, 429, and 317. All of the above findings were used to develop a model for the structure of carbonized charcoal that is consistent with the biocarbon's oxygen content, microporosity and surface area, electrical conductivity, radical content, and its MALDI-TOF spectra. The removal of inorganic mineral constituents from various biomass feedstocks was achieved via simple washing/soaking techniques using two different aqueous media; deionized water and citric acid. The most effective and consistent demineralization treatment for removing minerals from biomass involved a hot 0.1 molL-1 citric acid percolation treatment, ca. 67% of inorganic mineral matter was removed. Mineral matter at the levels present in typical biomass derived charcoals and carbons had no significant influence upon the surface area or the electrical resistivity in carbonaceous materials after high heat treatment (950 C).

Detection modalities that can evaluate the early stages of dental caries are indispensable. The purpose of this thesis is to evaluate the efficacy of photothermal radiometry and modulated luminescence (PTR-LUM) to non-destructively detect and quantify simulated enamel caries. Two experiments were performed based on the PTR-LUM detection mode: back-propagation or transmission-mode. Artificial demineralized lesions were created in human molars and a subset was further exposed to an artificial remineralizing solution. PTR-LUM frequency scans were performed periodically during de/re-mineralization treatments. PTR data was fitted to a theoretical model based on optical and thermal fluxes in enamel to extract opto-thermophysical parameters. Lesion validation was performed using transverse microradiography (TMR). Optical and thermal properties changed with the development and repair of the caries lesions while theory-derived thicknesses paralleled those determined microradiographically. These trends coupled with the uniqueness-of-fit of the generated parameters illustrate the efficacy of PTR- LUM to non-destructively detect and quantify de/re-mineralized lesions.

Detection modalities that can evaluate the early stages of dental caries are indispensable. The purpose of this thesis is to evaluate the efficacy of photothermal radiometry and modulated luminescence (PTR-LUM) to non-destructively detect and quantify simulated enamel caries. Two experiments were performed based on the PTR-LUM detection mode: back-propagation or transmission-mode. Artificial demineralized lesions were created in human molars and a subset was further exposed to an artificial remineralizing solution. PTR-LUM frequency scans were performed periodically during de/re-mineralization treatments. PTR data was fitted to a theoretical model based on optical and thermal fluxes in enamel to extract opto-thermophysical parameters. Lesion validation was performed using transverse microradiography (TMR). Optical and thermal properties changed with the development and repair of the caries lesions while theory-derived thicknesses paralleled those determined microradiographically. These trends coupled with the uniqueness-of-fit of the generated parameters illustrate the efficacy of PTR- LUM to non-destructively detect and quantify de/re-mineralized lesions.

There is an increasing awareness in clinical dentistry of the need to better understand the aetiology and management of tooth wear, as increasing numbers of elderly patients are retaining their natural teeth to a stage when they present with extensive wear. In addition, more younger patients are presenting with wear of both primary and permanent teeth. In order to comply with the philosophy of minimal intervention dentistry, clinical management of tooth wear should focus on early detection and prevention before a restorative approach is considered. Fluoride is a commonly used agent in the management of tooth wear, with previous studies showing that it can protect teeth against erosion (at around pH 2.0 and 3.0) and toothbrush abrasion in an acidic environment (at around pH 3.0). However, it does not reduce attritional wear between opposing tooth specimens. Nightguards are commonly used to prevent attritional wear but there is still a need to improve preventive strategies to manage the risk of erosive tooth wear. Previous in vitro studies have shown that a remineralizing agent in the form of CPP-ACP (casein phosphopeptide – amorphous calcium phosphate) can reduce erosion of both enamel and dentine by white wine. A recent study has also highlighted the potential lubricating and remineralizing properties of a CPP-ACP containing paste (Tooth Mousse®, G C Asia Pty Ltd) in reducing dentine wear in both an acidic environment (pH 3.0) and a near neutral environment (pH 6.1). In this context, it is desirable to investigate the effect of CPP-ACP on enamel wear under conditions simulating various clinical situations and to better understand the nature of third-body components at the wear interface. The aims of the present study were: (i) to determine the effect of CPP-ACP on enamel wear under conditions simulating three clinical situations: heavy attrition with gastric regurgitation (at pH 1.2); toothbrush abrasion after an erosive episode (at pH 3.2); and erosion from gastric regurgitation (at pH 1.2), and (ii) to clarify its mode of action by characterizing the enamel surface treated with CPP-ACP. Electro-mechanical tooth wear machines were used to simulate attrition and toothbrush abrasion in combination with erosion, but no machine was used in experiments investigation erosion alone. The effect of paste containing CPP-ACP in reducing erosive tooth wear was also compared with that without CPP-ACP. Enamel surfaces with and without treatment with CPP-ACP were then characterized by using Time of Flight – Secondary Ion Mass Spectrometry (ToF-SIMS). CPP-ACP was found to reduce enamel wear under conditions simulating heavy attrition combined with gastric regurgitation, and toothbrush abrasion after an erosive episode. However, it did not protect enamel from erosion under conditions simulating gastric regurgitation alone, indicating that its lubricating effect was more pronounced than its remineralizing effect. Silicone and ethyl siloxane were present in trace amounts on the enamel surface treated with Tooth Mousse®, thus they were found to be included in its formulation. These findings imply that CPP-ACP nanocomplexes and silicon can act as third body components to lubricate the wear interface. The findings presented in this thesis have implications for clinical management of tooth wear and may lead to new strategies of tooth wear prevention. Although some caution is needed in extrapolating these findings to the in vivo situation, it should be noted that in vitro studies provide valuable insights into separate components of the tooth wear process that are often difficult to distinguish in clinical situations. Overall, this thesis provides new information about the role of CPP-ACP in reducing erosive enamel wear and provides a basis for future experimental and clinical studies focussing on tooth wear prevention. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1379897 / Thesis (Ph.D.) -- University of Adelaide, School of Dentistry, 2009

Thesis (M.S.)--West Virginia University, 2005. / Title from document title page. Document formatted into pages; contains x, 243 p. : ill. (some col.). Vita. Includes abstract. Includes bibliographical references (p. 128-139).