Avaliaram-se clinicamente e por meio de radiografias interproximais, 558 restaurações de amálgama e 81 de resina composta em dentes posteriores, em 96 pacientes adultos atendidos na disciplina de Clínica Integrada da Faculdade de Odontologia da Universidade de São Paulo. Foram registrados os seguintes critérios: cárie secundária, falta de integridade marginal, falta de contato interproximal, condição da superfície oclusal das restaurações, falta de material restaurador, presença de fratura da restauração ou do dente e excessos interproximais, enumerados de 1 a 7, respectivamente. Somente foi considerado 1 critério para cada restauração. Coletaram-se informações referentes à idade, gênero, presença de doenças sistêmicas, dieta, índice de placa bacteriana, freqüência de escovação, uso do fio dental e substâncias fluoretadas para bochecho. A análise estatística baseou-se nos testes de qui-quadrado e exato de Fisher. A análise clínica das restaurações dentárias demonstrou que das 639 restaurações avaliadas, 325 apresentaram um dos critérios utilizados, sendo o critério 4 (oxidação, corrosão e descoloração aceitável) mais freqüente, seguido do critério 1 (cárie secundária). Pode-se concluir que: o principal defeito identificado nas restaurações de amálgama foi oxidação e sobrecontorno (50,34%), seguido de cárie secundária (19,33%); enquanto que para as resinas compostas foi cárie secundária (40%), seguido de alteração de cor aceitável (28%); houve associação entre o tipo de material restaurador (amálgama) e o critério 4 (corrosão e oxidação, p<0,0001) o que 8 não ocorreu com os demais critérios; houve associação entre placa bacteriana e cárie secundária (p=0,046), não houve associação entre placa bacteriana e gênero (p=0,755), não houve associação entre cárie secundária e dieta (p=0,407), cárie secundária e relato de doenças (p=0,329), cárie secundária e freqüência de escovação (p= 0,745) e placa bacteriana e freqüência de escovação (p= 0,903). / It was clinical evaluated 558 amalgam restorations and 81 resin restorations in posterior teeth. It was registered in a own paper these failures of restorations: secondary caries, defective margins, contact faulty, loose of restorative material, poor conditions of oclusal surface restoration, fracture of restoration or fracture of tooth structure and interproximal cervical area over contoured. These failures were recorded by the number one until seven, in order. It was evaluated 96 adults patients from Clínica Integrada in FOUSP. To determine the conditions of oral environment of these patients were asked to them about age; sex; the conditions of health; dietary, act of dental brushing, use of fluoride substances, use of dental prosthetics and buccal open in millimeters. The data were then analyzed by chi-quadrado and Fisher tests. The clinical analyze showed that 325 restorations had failures and the most failure was poor conditions of oclusal surface restorations and secondary caries. An overall view of the results allowed to conclude that main failure in amalgam restorations was poor conditions of oclusal surface restorations (50,34%) and secondary caries (19,33%); related to resins was secondary caries (40%) and inadequate color (28%); there was association between 4 criteria and amalgam restorations (p<0.0001), there was association between plaque and secondary caries (p= 0,046); there wasn’t association between caries and act of brushing (p=10 0,745), caries and dietary (p= 0,407), caries and diseases (p= 0,329), plaque and gender (p= 0,755) and plaque and act of brushing (p=0,903).

Imagemaking is a universal impulse experienced by all human cultures. In the continual pursuit to create compelling and engaging forms, efforts to permit images to interact in dynamic ways in extended space have been the subject of considerable exploration. The often sought-after goal is to break the surface of the paper without sacrificing the essence of the image. My current research is the investigation of Smooth-On 300 series Semi-Rigid Urethane Casting Resin and its interaction with various laser jet inks on diverse paper or paper analogous mediums. Purely on accident, it was discovered that one could easily transfer printed images onto the casting resin if it was poured directly on the print. This has allowed for a method of image manipulation in a manner that has yet to be thoroughly explored. Several experimental pours and projects have been completed to test the limits and potentiality of this new media. The results seem promising and warrant farther exploration of this exciting new development.

>Magister Scientiae - MSc / Introduction: Together with bonding to both enamel and dentine, an ideal restorative material would display physical properties similar to that of natural tooth tissue and would not be prone to degradation as a result of the oral environment. This includes changes in colour. Glass ionomer technology has undergone many changes to its original chemistry since it was developed in the early 1970’s. In 1988 resin-modified glass ionomers were introduced and in 2008, nano-ionomers were introduced. As a result of the progression in material sciences and the use of more sophisticated techniques and methods in restorative dentistry, it is possible to accomplish much improved aesthetics and functional durability of a restoration, both anteriorly and posteriorly. However, for as long as aesthetic restorations have been available, and in spite of advances in material structure and performance, one of the greatest challenges facing clinicians still remains that aesthetic restorations have to be replaced relatively frequently as staining and discolouration is a common problem. Aim of the study: The aim of this study was to determine the stainability of four resin-modified glass ionomers and one glass ionomer cement when exposed to a staining broth. Objectives: To record any change in colour before and after exposing the sample with the staining broth using a spectrophotometer, to compare the stainability, to examine the depth of staining using a light microscope and to observe the particle size of the powder and the surface texture using Scanning Electron Microscopy of the four resin- modified glass ionomer cements and one glass ionomer cement. Materials and Methods: Four resin-modified glass ionomers (one nano-ionomer) and one glass ionomer (zinc-reinforced ionomer) were selected. All were shade A2, except for Vitremer™ which was not available in A2. 15 discs of each material were prepared. The discs were 15 mm in diameter and 2 mm in thickness. All the materials were handled and cured according to the manufacturers’ instructions. After curing, only one side of each disc was polished using Sof-Lex™ discs (3M ESPE, USA). The unpolished side of each disc was designated as a matrix finish. The specimens were all immersed in distilled water at 37 °C for one week. They were then immersed in a staining broth for a period of one week and readings were taken after a period of 2 hours, 4 hours, 8 hours, 24 hours and one week. Colour was read on each side of each disc at the indicated intervals with a spectrophotometer. The colour difference was calculated using the CIELAB colour co-ordinates. Sample discs were then sectioned to determine the depth of staining. An additional sample disc of each material was made for observation with the SEM and was therefore not stained. Also, an unmixed sample of each material was prepared for examination with the SEM. Results: In general, for all materials there was an increase in staining when assessed with the colour difference between the baseline colour and the 7 day reading. Ketac™ N100, showed the highest total colour change of 43.84 for the unpolished surface followed by Riva™ which showed the total colour change of 28.55 for the unpolished surface. This was similar to Fuji II LC® which had a total colour change of 28.16 for the unpolished surface. For Vitremer™, the total colour change increased to 18.07 for the unpolished surface. For the unpolished surfaces, ChemFil™ Rock showed the least colour difference from baseline to 7 days (ΔE*ab = 10.45), followed by Vitremer™ (ΔE*ab = 18.07). Both Fuji II LC® and Riva™ Light Cure showed similar colour change from baseline to 7 days for unpolished surfaces (ΔE*ab of 28.16 and 28.55 respectively). Ketac™ N100 showed the highest staining after 7 days in the staining broth with a colour difference of 43.84. For the polished surfaces, the colour change for Fuji II LC® was 25.72 which was similar to Riva™ Light Cure which was 22.44 and Ketac™ N100 which showed a colour change of 22.79 on the polished surface. ChemFil™ Rock showed the least colour change of 17.69 for the polished surface followed by Vitremer™ which showed a colour change of 23.63 for the polished surface. Thus, for both the unpolished and polished surfaces there was a similar staining pattern. Conclusion: In this study it was demonstrated that all products evaluated in this study showed some degree of staining when exposed to a staining broth when evaluated using the ΔE*ab CIELAB colour evaluation. Ketac™ N100 showed the highest colour change compared to the other materials, but the reason for this was not explored. Both Vitremer™ and ChemFil™ Rock showed similar patterns of staining. / 2020-09-01

The pulp and paper industry in New Zealand annually produces over one hundred thousand dry tonnes of solid waste due to the treatment of pulp and paper mill effluents, the majority of which is currently landfilled. The New Zealand Waste Management Strategy (2002) has set a target for the diversion of commercial organic wastes from landfill to beneficial use to exceed 95% by 2010 . Effluents produced by softwood pulp mills, such as in New Zealand, contain high concentrations of naturally derived resin extractive compounds that are toxic to fish and other aquatic organisms. Improvements in waste water treatment technology has enabled the industry to meet rigorous discharge standards, however, this has resulted in an increase in the production of pulp mill effluent solids which require disposal. This has become an issue for the pulp and paper industry, especially as current landfill space is limited. Land application has been used for many years as a means of disposal of pulp mill wastes. While most studies investigating land application of pulp mill effluent solids have concluded that the risk posed to the environment is low, few have investigated the potential toxicity of these wastes to soil organisms, and these studies did not directly address the effects of resin extractive compounds. Resin extractives have been shown to be recalcitrant and to accumulate in anaerobic sediments. It is not known to what extent resin extractives are bioavailable or degradable in land applied Pulp mill effluent solids (PMES), or their potential to bioaccumulate in soil organisms. This PhD thesis research sought to extend the knowledge on the environmental fate and effects of pulp mill effluent wastes. It focused on terrestrial systems, which have not been well studied in this respect. Four chemically distinct softwood pulp mill effluent solids, a primary treatment solid and three secondary treatment biosolids, were used to investigate their effects on soil organisms and soil functions. An interdisciplinary approach was adopted, which incorporated three main areas of study, as follows: 1. A comprehensive resin extractives analysis of the pulp mill effluent solids undertaken so that effects on soil organisms and soil functions could be related to the resin extractives chemistry of the individual pulp mill effluent solids tested. 2. A battery of bioassays used to investigate the toxicity of the selected pulp mill effluent solids. 3. A field trial set-up to investigate how pulp mill effluent solids affected soil functions and also to investigate the decomposition of pulp mill effluent solids and of resin extractives in these solids. Three hypotheses tested were: I. Pulp mill effluent solids are toxic to soil organisms. II. Resin extractives in pulp mill effluent solids are recalcitrant in the terrestrial environment. III. Pulp mill effluent solids will cause significant measurable negative impacts on soil functional capacity. A wide range of resin extractives compounds were identified in pulp mill effluent solids, and concentrations of individual compounds varied widely between the different pulp mill effluent solids tested. During the two years after field application of the pulp mill effluent solids, resin extractives declined, however, decay rates of individual compounds were variable. The decay rate of compounds was influenced by the type of pulp mill effluent solids containing these compounds and not by the initial concentration of compounds. All compounds, including resin acids, degraded rapidly in the applied primary solid and in one of the applied biosolids, with average half-lives calculated ranging from three to twelve months. In the other biosolids, resin acids were recalcitrant with average half-lives calculated to be nearly ten years. Laboratory bioassays conducted on oats, earthworms and enchytraeid worms indicated that pulp mill effluent solids had low toxicity to these organisms. An aquatic bioassay organism, however, was acutely affected by aqueous extracts from pulp mill effluent solids. Earthworms were shown to bioaccumulate some resin extractive compounds to a limited extent, indicating that resin extractives were bioavailable in pulp mill effluent solids. Enchytraeid reproduction was reduced by exposure to some pulp mill effluent solids but this was not correlated to resin extractives concentration of the solids tested. Field applied pulp mill effluent solids significantly enhanced the fluxes of CO2 from the soil surface. When mass losses of pulp mill effluent solids carbon were taken into account, it was shown that these solids had little effect on soil respiration. Needle litterbags were placed above and below pulp mill effluent solids and in the litter horizon of a control treatment for 12 months. Needle litter decomposition was not significantly different between treatments, however, changes in enzyme activities were detected in litter beneath pulp mill effluent solids compared to control needle litter that had not been exposed to pulp mill effluent solids. The decomposition rate of field applied pulp mill effluent solids was slow, with half-lives extrapolated to be between five and twenty five years. The decomposition rate appeared to be influenced by the pools of carbon available for decomposition, with primary solids decaying significantly faster than biosolids due to a higher cellulose component. The conclusions of the PhD thesis research are, therefore, that generally, pulp mill effluent solids used in the study were demonstrated to be relatively benign and appear to pose a low risk to the terrestrial ecosystem when applied to soil. However, a cautious approach is still recommended to land application, based on the extensive evidence of disruption to aquatic ecosystems, and because pulp mill effluent solids will take many years to decompose and resin acids are recalcitrant in some pulp mill effluent solids. Further research is recommended to elucidate mechanisms of action by resin extractives in soil organisms and the ultimate fate of these compounds in the soil compartment.

The structure, functionality, isolation methods and applications of whey components, particularly the proteins and lactose, have been extensively studied. These studies have had a great impact on the food industry where whey components are increasingly being used as food ingredients. Two generations of whey protein product, namely Lactalbumin, produced by heat-induced precipitation, and Whey Protein Concentration/ Isloate, produced by ultrafiltration/ ion exchange chromatography, have been commercialised. Crystalline lactose in the food and pharmaceutical grades is also being produced. Recently, research activities in whey fractionation have shifted to the isolation of the minor components. This thesis is aimed at developing a Total Whey Utilization strategy by which the several components of the whey stream would be completely recovered by fractionation, resulting in little or no residue to be disposed of in the wastewater stream. Therefore, this study was initially dedicated to the development of novel separation methods which would be suitable for the Total Whey Utilization process. The development of those techniques revealed some previously unknown feature of whey components. The mechanisms of the separation methods have been also investigated. Although crystallization is an efficient method for fractionation or purification, its disadvantage is that the mother liquor is a wastewater containing high salt and BOD (Biological Oxygen Demand). The chromatographic method has been investigated in this work to separate the mother liquor or permeate into lactose and mineral fractions such that a goal of this thesis, namely a 'clean' water stream after processing whey, can be finally achieved. These studies have focused on the effect of resin type, salt form of the resin and the operating conditions on the separation of the lactose and mineral fraction. / Doctor of Philosophy (PhD)

In 1995, the Swedish government recommended the discontinuation of amalgam as restorative in paediatric dentistry. Because the mercury content in amalgam constitutes an environmental hazard, its use has declined. The use of resin composites is increasing, but the polymerisation shrinkage of the material is still undesirably high, and the handling of uncured resin can cause contact dermatitis. A new restorative material has recently been developed in Sweden as an alternative to amalgam and resin composite: a calcium aluminate cement (CAC). CAC has been marketed as a ceramic direct restorative for posterior restorations (class I, II) and for class V restorations. This thesis evaluates mechanical properties and clinical durability of the calcium aluminate cement when used for class II restorations. Hardness, in vitro wear, flexural strength, flexural modulus, and surface roughness were evaluated. A scanning electron replica method was used for evaluation of the interfacial adaptation to tooth structures in vivo. The durability was studied in a 2-year intra-individually clinical follow-up of class II restorations. Major results and conclusions from the studies are as follows: • The CAC was a relatively hard material, harder than resin-modified glass ionomer cement but within the range of resin composites. The CAC wore less than resin-modified glass ionomer cement but more than resin composite. • Flexural strength of CAC was in the same range as that of zinc phosphate cement and far below that of both resin composite and resin-modified glass ionomer cement. Flexural modulus of CAC was higher than both resin composite and resin-modified glass ionomer cement. The low flexural strength of CAC precludes its use in stress-bearing areas. • Surface roughness of CAC could be decreased by several polishing techniques. • For CAC restorations, interfacial adaptation was higher to dentin but lower to enamel compared with resin composite restorations. Fractures were found perpendicular to the boarders of all CAC restorations and may indicate expansion of the material. • After 2 years of clinical service, the class II CAC restorations showed an unacceptably high failure rate. Material fractures and tooth fractures were the main reasons for failure.

Background: Human salivary esterases have been shown to degrade dental resin composite restorations in vivo. Objective: To optimize in vivo protocols to recover biodegradation products and to compare the biostability of urethane-modified-bisGMA- (ubis) and bisGMA-based (bis) commercial resin composites. Methods: Class V and III composite restorations were placed in patients using adhesive and composite resin. Gingival crevicular fluid (GCF), plaque and a 2-minute oral rinse with 20% ethanol in saline (n=10) were collected immediately and 7-days after restoration placement. Samples were analyzed for biodegradation products using high performance liquid chromatography. The oral rinse protocol was then used to compare the bis and ubis composite resins (Z250, 3M; TPH, Dentsply) (n=58). Results and conclusions: The bisGMA composite matrix derived product, bishydroxypropoxyphenylpropane (BisHPPP) was only detected from oral rinse collected immediately after restoration placement. There was no statistical difference in the amount of bisHPPP collected from bis and ubis composite resins. This research was supported by CIHR (MOP 68947).

Background: Human salivary esterases have been shown to degrade dental resin composite restorations in vivo. Objective: To optimize in vivo protocols to recover biodegradation products and to compare the biostability of urethane-modified-bisGMA- (ubis) and bisGMA-based (bis) commercial resin composites. Methods: Class V and III composite restorations were placed in patients using adhesive and composite resin. Gingival crevicular fluid (GCF), plaque and a 2-minute oral rinse with 20% ethanol in saline (n=10) were collected immediately and 7-days after restoration placement. Samples were analyzed for biodegradation products using high performance liquid chromatography. The oral rinse protocol was then used to compare the bis and ubis composite resins (Z250, 3M; TPH, Dentsply) (n=58). Results and conclusions: The bisGMA composite matrix derived product, bishydroxypropoxyphenylpropane (BisHPPP) was only detected from oral rinse collected immediately after restoration placement. There was no statistical difference in the amount of bisHPPP collected from bis and ubis composite resins. This research was supported by CIHR (MOP 68947).

Resin and fatty acids (RFA) are predominantly components of coniferous trees having the natural function of protecting against microbial damage. These compounds are released from wood during the pulping process and a fraction reaches the wastewater treatment system. RFA are acutely toxic to aquatic organisms at concentrations on the order of parts per million, and their presence has been linked to toxicity outbreaks in receiving waters following process upsets. The chronic toxicity of resin and fatty acids in complex effluent matrices is poorly understood. Furthermore, the role of hydrophobic, pulp-derived solids as a removal pathway from wastewater streams has not been comprehensively studied. The objectives of this dissertation have been to quantify the relationship between resin and fatty acid concentration and chronic toxicity and to determine the role of partitioning in the removal of these compounds from pulp mill wastewater streams. Field and laboratory studies were conducted to measure toxicity using the Microtox™ whole effluent toxicity and Ceriodaphnia dubia 7-day, survival and reproduction bioassays. One resin acid in particular, dehydroabietic acid, was found to account for a significant fraction of final effluent chronic toxicity. Dissolved and sorbed RFA concentrations were quantified by solvent extraction, methyl ester derivatization, and GC-FID analysis. Partitioning to suspended solids was found to be a major removal pathway for the RFA from the effluent treatment system. A kinetic model for flotation was applied and compared to experimental data. Flotation was found to be effective at selectively removing RFA bound to pulp-derived solids from pulp mill and bleach plant sewers at moderate to high pH.

No description available.