Yes / Objective: This project sought to investigate whether an association may be observed between isotopic stress indicators and skeletal evidence of pathological conditions. Materials: Deciduous and permanent teeth of 15 non-adults from two contemporaneous mid-19th century London burial grounds (City Bunhill, Lukin Street). Methods: δ13C and δ15N was measured in the incrementally sectioned dentine collagen. Isotopic profiles for each individual included death during tooth development. Results: Individuals with skeletal evidence of chronic pathological conditions (e.g., rickets, tuberculosis) exhibited raised δ15N values of 0.5-1.7‰ in the months prior to death. Isotopic change consistent with chronic physiological stress prior to death was also recorded in two individuals with no skeletal evidence of disease. An offset was observed between co-forming bone and dentine δ15N values in both populations, indicating that bone and dentine are not recording the same isotopic changes. Conclusions: Isotopic change consistent with chronic physiological stress was observed in both those with and without skeletal evidence of disease, suggesting that adaptation to chronic stress in childhood was not uncommon within these 19th century London populations. Significance: Chronic physiological stress prior to death may be seen in the incrementally sampled dentine of non-adults who die during tooth formation. Limitations: The temporal resolution of current dentine micro-sampling methods may mask or minimise visibility of shorter-term periods of stress or dietary change. Suggestions for further research: Future research should further explore the relationship between specific skeletal pathologies and isotopic evidence for stress.

A series of studies on monomer to polymer conversion in adhesive systems was undertaken using micro-Raman spectroscopy. A database of micro-Raman spectra was compiled for identification of tooth tissues and materials. The degree of conversion was assessed as a function of time and light source. Linear and two-dimensional micro- Raman characterisations of the adhesive-dentine and resin-based composite-adhesivedentine interfaces were performed. The degree of monomer to polymer conversion of adhesive systems was correlated with the amount of eluted monomers obtained by highperformance liquid chromatography. The degree of conversion varied significantly depending on adhesive chemical composition, curing time and light source. It was impossible to specify one curing time applicable to all adhesive systems, due to differences in conversion kinetics. In general, conventional halogen light-curing units at twenty seconds curing time produced similar or higher degree of conversion in adhesive systems compared to high-power LED units at ten seconds. Significantly higher monomer conversion was found in the adhesive layer compared to the hybrid layer in both etch-and-rinse and self-etch systems. Etch-and-rinse adhesive systems formed thicker hybrid layers compared to self-etch systems. Micro-Raman spectroscopy gave a more precise indication of dentine demineralisation and adhesive penetration than scanning electron microscopy and indicated that the hybrid layer is a gradual transitional zone between the adhesive layer and un-affected dentine. The absolute amount and weight percent of eluted monomers varied in all tested adhesive systems. In most adhesive systems, more than 90% of eluted monomers were detected within the first one hour of immersion. Overall, no correlation was found between the degree of conversion and the amount of eluted monomers.

A hipersensibilidade dentinária (HD) é descrita na literatura como uma dor aguda, de curta duração, provocada por estímulos térmico, tátil, osmótico, químico ou evaporativo em região de exposição dentinária, não sendo atribuída à dor causada pela presença de defeito ou doença de origem dentária. Esse tipo de acometimento tem sido cada vez mais reportado pelos pacientes, em vista disso, o objetivo desse estudo foi avaliar a extensão e gravidade de HD, bem como sua associação com indicadores periodontais [índice de placa (IP), índice gengival (IG) e recessão gengival (RG)] em uma amostra composta por 132 indivíduos com HD diagnosticada por meio de estímulo térmico/evaporativo (jato de ar) associada à escala Schiff. Análises descritivas foram feitas e as porcentagens médias de IP e IG foram estimadas considerando 6 sítios por dente e também 3 sítios das faces vestibulares. Além disso, os dados foram analisados através de modelos uni e multivariados utilizando análises de regressão linear. A média de idade foi de 30.66±10.33, sendo o sexo feminino mais afetado pela HD (83.3%). Foi possível observar que a HD esteve associada à recessão gengival. A prevalência de dentes com recessão gengival foi de 17.17%, enquanto que a prevalência de recessão em dentes com HD foi de 77.1% e a média de recessão vestibular foi de 1.58±0.87. Quando considerada a média de dentes com 1 ou mais milímetros de recessão, observou-se que, em média, 4.48 dos dentes apresentaram esta condição. Um maior número médio de dentes com recessão e menores escores médios de IP nos sítios vestibulares apresentaram-se signicativamente associados ao número médio de dentes com HD. A gravidade da HD nos pacientes foi significativamente influenciada por maior média de recessão gengival e foi maior nos pacientes do sexo feminino. Dentes que possuíam maiores médias de recessão e maiores escores médios de IP e menores de IG nos sítios vestibulares apresentaram maiores valores na escala Schiff (p<0.05). Frente aos achados, é possível observar que portadores de HD têm um grande número de dentes afetados por esta condição e que estes apresentam recessão. Além disto, nos dentes que apresentam HD, a gravidade desta está associada a presença de mais placa e melhor condição gengival, além da extensão da recessão. / Dentin hypersensitivity (DH) is described in the literature as an acute short-term pain caused by thermal, tactile, osmotic, chemical or evaporative stimuli in the region of dentin exposure and not attributed to pain caused by the presence of defect or disease of dental origin. Therefore, the aim of this study was to evaluate the extent and severity of DH, as well as its correlation with periodontal indicators [plaque index (PI), gingival index (GI) and gingival recession (GR)] in 132 individuals with DH diagnosed by thermal/evaporative (air blast) stimulation associated with the Schiff scale. Descriptive analyzes were made and the mean percentages of PI and GI were estimated considering 6 sites per tooth and also 3 buccal sites. In addition, the data were analyzed using univariate and multivariate models using linear regression analysis. The mean age was 30.66 ± 10.33, female sex being more affected by DH (83.3%). It was possible to observe that DH was associated to gingival recession. The prevalence of teeth with gingival recession was 17.17%, while the prevalence of recession in teeth with DH was 77.1%. The mean of vestibular recession was 1.58 ± 0.87, and when considered the mean teeth with 1 or more millimeters recession, it was observed that, a mean of 4.48 teeth presented this condition. A higher mean number of teeth with recession and lower mean PI scores in the vestibular sites were associated (p<0.001) with the mean number of teeth with DH. The severity of DH in number of patients was significantly influenced by the higher mean of gingival recession and was higher in the female patients. Teeth that had higher recession mean and higher mean PI scores at the buccal sites, but lower GI scores at this sites, presented significantly higher values on the Schiff scale (p <0.05). In view of the findings, it is possible to observe that DH patients have a large number of teeth affected by this condition and that these present gingival recession. In addition, in the teeth that present DH, the severity is associated with the presence of more plaque and better gingival condition, in addition to the extent of the recession.

Este estudo foi realizado a fim de avaliar a microdureza da dentina radicular adjacente a materiais restauradores contendo fluoretos após desafios erosivos. Foi utilizado um delineamento crossover de duas fases de 4 dias consecutivos cada. Cento e doze fragmentos de dentina bovina foram obtidos, nos quais foi confeccionada uma cavidade padronizada no centro de cada um. Estas cavidades foram restauradas aleatoriamente com cimento de ionômero de vidro (Ketac-fil) ou resina composta (Filtek Z-250). Em seguida, os fragmentos restaurados foram distribuídos aleatoriamente entre os 14 voluntários, montados em aparelhos, cada um com 4 espécimes restaurados com o mesmo material. A partir do segundo dia, metade do aparelho, com dois espécimes, foi imersa em refrigerante de limão por 90 s, quatro vezes por dia, fora da boca por 3 dias. Após um intervalo de 3 dias, fragmentos restaurados com o material ainda não utilizado foram montados no aparelho e foi iniciada a segunda fase do experimento. Após os desafios erosivos, foram realizadas as medidas da microdureza da dentina adjacente às restaurações. Independente do material empregado, os espécimes erodidos apresentaram menores valores de microdureza (p<0.0001). Com relação aos materiais restauradores, foi verificado que a dentina, nas condições deste estudo, apresentou maiores valores de microdureza quando restaurada com cimento de ionômero de vidro (p<0.0001). Sendo assim, podemos concluir que o cimento de ionômero de vidro diminui a progressão da erosão da dentina radicular adjacente à restauração. / This study sought to evaluate the microhardness of root dentine adjacent to fluoride-containing restorative materials after erosive challenge. A cross-over study was performed in two phases of 4 consecutive days each. One hundred and twelve bovine root dentine slabs were obtained, and standardized box-shaped cavities were prepared at center of each specimen. The prepared cavities were randomly restored with glass-ionomer cement or composite resin. The slabs were randomly assigned among 14 volunteers, which wore intraoral palatal device containing 4 restored root dentin slabs. Starting on the second day, half of the palatal acrylic devices were immersed extraorally in a lemonade-like carbonated soft drink for 90 seconds, four times daily for 3 days. After 3-day wash-out, dentine slabs restored with the alternative material were placed into palatal appliance and the volunteers started the second phase of this study. After erosive challenges, microhardness measurements were performed. Regardless of the restorative material employed, eroded specimens demonstrated lower microhardness value (p<0.0001). At any given dentine condition examined in this study, dentine restored with glass-ionomer cement showed higher microhardness values (p<0.0001). It may be concluded that the glass-ionomer cement decreases the progression of root dentine erosion at restoration margin.

This study used Backscattered electron imaging (BSE) and X-ray Microanalysis to qualitatively and quantitatively investigate morphology and elemental composition of ankylotic adaptation in the periodontium following hypothermic insult to their maxillary first molars. This method has been shown in previous studies to induce aseptic root resorption along with ankylotic changes within the periodontal ligament (PDL). A secondary objective was to assess the pulpal changes that occurred concurrent with the changes in the periodontium. Twenty-eight eight week old Sprague Dawley rats were divided into four groups of seven animals corresponding to one of four observation periods i.e.: t₁= 7 days, t₂= 14 days, t₃= 21 days, t₄ = 28 days. At t=0 days, six animals in each group received a thermal insult as a continuous 20 minute application of dry ice (CO₂ at -81⁰C) to the crowns of their upper right maxillary molar. The untreated left molars were used as controls. The remaining rat within each group did not receive the dry ice. All rats were given two sequential bone labels, calcein 5mg/kg and alizarin red 30mg/kg, administered intraperitoneally 8 days apart. The timing of the labels was such that all rats were euthanased 2 days after the last label. Following sacrifice, the maxillae were dissected out, fixed in ethanol and embedded in methylmethacrylate. Ten microns thick, undecalcified maxillary first molar coronal sections through the furcation were obtained. For every 3 out of 10 sections: the first was left unstained and undecalcified; the second stained with Von Kossa/haematoxylin & eosin; and the third decalcified and stained with haematoxylin & eosin. Unstained sections were viewed under fluorescence, while transmitted light microscopy was used for the other sections. Following initial analysis, the unstained, undecalcified sections were de-coverslipped and carbon coated. These sections were investigated with scanning electron microscopy and Energy Dispersive X-ray Spectrometry (EDS). Quantitative spot analysis and element mapping was performed on alveolar bone, ankylotic areas, cementum and dentine. A linear mixed effects model was employed to investigate any interaction between the four tissues of interest. A focal pattern of ankylosis was observed at days 14 and 21 in three rats. No ankylosis was observed in the control teeth. SEM revealed a focal type of ankylosis with central nodules of mineralized tissue forming within the PDL. Bridging between bone and dentine occurred with fine trabeculae which extended from the central mineralized nodule. Bridging was progressive and was more extensive at day 21 compared to day 14. At day 28, no ankylosis was observed. EDS analysis revealed that the ankylotic tissue was composed of major constituents Calcium and Phosphorous along with trace elements of Mg and Na. This was comparable to the surrounding alveolar bone, cementum and dentine. There was no statistically significant difference in the Ca/P ratios, Mg when ankylotic material was compared to bone. There was a trend towards elevated Na levels in ankylosis but this was not statistically significant relative to bone. Mg in dentine was lower than for all the other tissues and Na was higher in dentine when compared to bone and cementum. In the pulp, hypothermic injury demonstrated alteration of the odontoblast layer, reduction in cellularity, vascular alterations and tertiary dentin formation. At the 28 day observation period, the cellular and vascular changes had returned to levels comparable to the control teeth, indicating successful pulpal healing and regeneration. Marked tertiary dentine deposition was also observed at days 14, 21 and 28. Pulp chambers were visibly smaller due to tertiary dentine formation, however no pulp necrosis was observed. Thus the aseptic root resorption model, using a continuous 20 minute application of dry ice, suggested the occurrence of reversible pulpal tissue alterations compatible with an inflammatory repair process. The observation of ankylosis initiating as centralised nodules within the PDL suggest that the origins may be a consequence of osteogenic potential from PDL stem cells. The null hypothesis that a single, prolonged thermal insult on a rat molar does not have an effect on mineralized tissue formation and that ankylotic tissue is similar to bone was rejected. ABSTRACT There is a presumption that the ankylotic region formed after periodontal ligament (PDL) injury represents an unremarkable bony repair process. Essentially, the injury triggers an osteogenic repair response and the ankylotic tissue merely represents alveolar bone. There is uncertainty whether the oestogenic event is predominantly osteoblast driven, cementoblast directed, or a consequence of osteogenic potential from PDL stem cells. In this study, twenty-eight Sprague Dawley rats were divided into four groups of six animals, corresponding to one of four observation periods, and received a thermal insult as a continuous 20 minute application of dry ice to the crowns of their upper right maxillary molar. The appearance of ankylotic tissues was examined using backscattered electron images using a scanning electron microscope (SEM) equipped with an Energy Dispersive X-ray Analyser (EDS). The Ca, P, and trace elements contents were determined by EDS from four different hard tissue regions: ankylosis; bone; dentine and cementum, and the Ca/P ratios were calculated. Ankylosis was observed at days 14 and 21 in 3 rats and was not seen at day 28. No ankylosis was observed in the control teeth. BSE imaging revealed a focal type of ankylosis with central nodules of mineralized tissue forming within the PDL. The morphological features of ankylotic tissue differed to that of alveolar bone and dentine. Bridging between bone and dentine occurred with fine trabeculae which extended from the central mineralized nodule. EDS analysis showed that the ankylotic tissue was composed of major constituents Ca and P along with trace elements of Mg and Na. This was comparable to the surrounding alveolar bone, cementum and dentine. There was no statistically significant difference in the Ca/P ratios, Mg, and Na between ankylotic material and bone. Statistically significant differences was evident in Mg content between ankylotic material compared to dentine and cementum. Na content was higher in dentine than in ankylotic material. The results of this study indicate that, histochemically, ankylotic material is similar to bone. However, the appearance of ankylotic material as centralised foci with a morphology different from bone suggest that ankylosis may originate from an osteoblastic phenotype originating within PDL. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1522156 / Thesis (D.Clin.Dent.) -- University of Adelaide, School of Denstistry, 2010

This study used Backscattered electron imaging (BSE) and X-ray Microanalysis to qualitatively and quantitatively investigate morphology and elemental composition of ankylotic adaptation in the periodontium following hypothermic insult to their maxillary first molars. This method has been shown in previous studies to induce aseptic root resorption along with ankylotic changes within the periodontal ligament (PDL). A secondary objective was to assess the pulpal changes that occurred concurrent with the changes in the periodontium. Twenty-eight eight week old Sprague Dawley rats were divided into four groups of seven animals corresponding to one of four observation periods i.e.: t₁= 7 days, t₂= 14 days, t₃= 21 days, t₄ = 28 days. At t=0 days, six animals in each group received a thermal insult as a continuous 20 minute application of dry ice (CO₂ at -81⁰C) to the crowns of their upper right maxillary molar. The untreated left molars were used as controls. The remaining rat within each group did not receive the dry ice. All rats were given two sequential bone labels, calcein 5mg/kg and alizarin red 30mg/kg, administered intraperitoneally 8 days apart. The timing of the labels was such that all rats were euthanased 2 days after the last label. Following sacrifice, the maxillae were dissected out, fixed in ethanol and embedded in methylmethacrylate. Ten microns thick, undecalcified maxillary first molar coronal sections through the furcation were obtained. For every 3 out of 10 sections: the first was left unstained and undecalcified; the second stained with Von Kossa/haematoxylin & eosin; and the third decalcified and stained with haematoxylin & eosin. Unstained sections were viewed under fluorescence, while transmitted light microscopy was used for the other sections. Following initial analysis, the unstained, undecalcified sections were de-coverslipped and carbon coated. These sections were investigated with scanning electron microscopy and Energy Dispersive X-ray Spectrometry (EDS). Quantitative spot analysis and element mapping was performed on alveolar bone, ankylotic areas, cementum and dentine. A linear mixed effects model was employed to investigate any interaction between the four tissues of interest. A focal pattern of ankylosis was observed at days 14 and 21 in three rats. No ankylosis was observed in the control teeth. SEM revealed a focal type of ankylosis with central nodules of mineralized tissue forming within the PDL. Bridging between bone and dentine occurred with fine trabeculae which extended from the central mineralized nodule. Bridging was progressive and was more extensive at day 21 compared to day 14. At day 28, no ankylosis was observed. EDS analysis revealed that the ankylotic tissue was composed of major constituents Calcium and Phosphorous along with trace elements of Mg and Na. This was comparable to the surrounding alveolar bone, cementum and dentine. There was no statistically significant difference in the Ca/P ratios, Mg when ankylotic material was compared to bone. There was a trend towards elevated Na levels in ankylosis but this was not statistically significant relative to bone. Mg in dentine was lower than for all the other tissues and Na was higher in dentine when compared to bone and cementum. In the pulp, hypothermic injury demonstrated alteration of the odontoblast layer, reduction in cellularity, vascular alterations and tertiary dentin formation. At the 28 day observation period, the cellular and vascular changes had returned to levels comparable to the control teeth, indicating successful pulpal healing and regeneration. Marked tertiary dentine deposition was also observed at days 14, 21 and 28. Pulp chambers were visibly smaller due to tertiary dentine formation, however no pulp necrosis was observed. Thus the aseptic root resorption model, using a continuous 20 minute application of dry ice, suggested the occurrence of reversible pulpal tissue alterations compatible with an inflammatory repair process. The observation of ankylosis initiating as centralised nodules within the PDL suggest that the origins may be a consequence of osteogenic potential from PDL stem cells. The null hypothesis that a single, prolonged thermal insult on a rat molar does not have an effect on mineralized tissue formation and that ankylotic tissue is similar to bone was rejected. ABSTRACT There is a presumption that the ankylotic region formed after periodontal ligament (PDL) injury represents an unremarkable bony repair process. Essentially, the injury triggers an osteogenic repair response and the ankylotic tissue merely represents alveolar bone. There is uncertainty whether the oestogenic event is predominantly osteoblast driven, cementoblast directed, or a consequence of osteogenic potential from PDL stem cells. In this study, twenty-eight Sprague Dawley rats were divided into four groups of six animals, corresponding to one of four observation periods, and received a thermal insult as a continuous 20 minute application of dry ice to the crowns of their upper right maxillary molar. The appearance of ankylotic tissues was examined using backscattered electron images using a scanning electron microscope (SEM) equipped with an Energy Dispersive X-ray Analyser (EDS). The Ca, P, and trace elements contents were determined by EDS from four different hard tissue regions: ankylosis; bone; dentine and cementum, and the Ca/P ratios were calculated. Ankylosis was observed at days 14 and 21 in 3 rats and was not seen at day 28. No ankylosis was observed in the control teeth. BSE imaging revealed a focal type of ankylosis with central nodules of mineralized tissue forming within the PDL. The morphological features of ankylotic tissue differed to that of alveolar bone and dentine. Bridging between bone and dentine occurred with fine trabeculae which extended from the central mineralized nodule. EDS analysis showed that the ankylotic tissue was composed of major constituents Ca and P along with trace elements of Mg and Na. This was comparable to the surrounding alveolar bone, cementum and dentine. There was no statistically significant difference in the Ca/P ratios, Mg, and Na between ankylotic material and bone. Statistically significant differences was evident in Mg content between ankylotic material compared to dentine and cementum. Na content was higher in dentine than in ankylotic material. The results of this study indicate that, histochemically, ankylotic material is similar to bone. However, the appearance of ankylotic material as centralised foci with a morphology different from bone suggest that ankylosis may originate from an osteoblastic phenotype originating within PDL. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1522156 / Thesis (D.Clin.Dent.) -- University of Adelaide, School of Denstistry, 2010

A hipersensibilidade dentinária (HD) é descrita na literatura como uma dor aguda, de curta duração, provocada por estímulos térmico, tátil, osmótico, químico ou evaporativo em região de exposição dentinária, não sendo atribuída à dor causada pela presença de defeito ou doença de origem dentária. Esse tipo de acometimento tem sido cada vez mais reportado pelos pacientes, em vista disso, o objetivo desse estudo foi avaliar a extensão e gravidade de HD, bem como sua associação com indicadores periodontais [índice de placa (IP), índice gengival (IG) e recessão gengival (RG)] em uma amostra composta por 132 indivíduos com HD diagnosticada por meio de estímulo térmico/evaporativo (jato de ar) associada à escala Schiff. Análises descritivas foram feitas e as porcentagens médias de IP e IG foram estimadas considerando 6 sítios por dente e também 3 sítios das faces vestibulares. Além disso, os dados foram analisados através de modelos uni e multivariados utilizando análises de regressão linear. A média de idade foi de 30.66±10.33, sendo o sexo feminino mais afetado pela HD (83.3%). Foi possível observar que a HD esteve associada à recessão gengival. A prevalência de dentes com recessão gengival foi de 17.17%, enquanto que a prevalência de recessão em dentes com HD foi de 77.1% e a média de recessão vestibular foi de 1.58±0.87. Quando considerada a média de dentes com 1 ou mais milímetros de recessão, observou-se que, em média, 4.48 dos dentes apresentaram esta condição. Um maior número médio de dentes com recessão e menores escores médios de IP nos sítios vestibulares apresentaram-se signicativamente associados ao número médio de dentes com HD. A gravidade da HD nos pacientes foi significativamente influenciada por maior média de recessão gengival e foi maior nos pacientes do sexo feminino. Dentes que possuíam maiores médias de recessão e maiores escores médios de IP e menores de IG nos sítios vestibulares apresentaram maiores valores na escala Schiff (p<0.05). Frente aos achados, é possível observar que portadores de HD têm um grande número de dentes afetados por esta condição e que estes apresentam recessão. Além disto, nos dentes que apresentam HD, a gravidade desta está associada a presença de mais placa e melhor condição gengival, além da extensão da recessão. / Dentin hypersensitivity (DH) is described in the literature as an acute short-term pain caused by thermal, tactile, osmotic, chemical or evaporative stimuli in the region of dentin exposure and not attributed to pain caused by the presence of defect or disease of dental origin. Therefore, the aim of this study was to evaluate the extent and severity of DH, as well as its correlation with periodontal indicators [plaque index (PI), gingival index (GI) and gingival recession (GR)] in 132 individuals with DH diagnosed by thermal/evaporative (air blast) stimulation associated with the Schiff scale. Descriptive analyzes were made and the mean percentages of PI and GI were estimated considering 6 sites per tooth and also 3 buccal sites. In addition, the data were analyzed using univariate and multivariate models using linear regression analysis. The mean age was 30.66 ± 10.33, female sex being more affected by DH (83.3%). It was possible to observe that DH was associated to gingival recession. The prevalence of teeth with gingival recession was 17.17%, while the prevalence of recession in teeth with DH was 77.1%. The mean of vestibular recession was 1.58 ± 0.87, and when considered the mean teeth with 1 or more millimeters recession, it was observed that, a mean of 4.48 teeth presented this condition. A higher mean number of teeth with recession and lower mean PI scores in the vestibular sites were associated (p<0.001) with the mean number of teeth with DH. The severity of DH in number of patients was significantly influenced by the higher mean of gingival recession and was higher in the female patients. Teeth that had higher recession mean and higher mean PI scores at the buccal sites, but lower GI scores at this sites, presented significantly higher values on the Schiff scale (p <0.05). In view of the findings, it is possible to observe that DH patients have a large number of teeth affected by this condition and that these present gingival recession. In addition, in the teeth that present DH, the severity is associated with the presence of more plaque and better gingival condition, in addition to the extent of the recession.

O objetivo do presente estudo foi desenvolver e caracterizar resinas adesivas contendo hidroxietil acrilamida (HEAA). Três grupos de resinas adesivas foram formulados, GHEAA33% (33,3% de HEAA + 66,6% de bisfenol A glicedil dimetacrilato - BisGMA), GHEAA50% (50% de HEAA + 50% de BisGMA) e GHEMA (33,3% de hidroxietil metacrilato - HEMA + 66,6% de BisGMA). Parâmetros como resistência à flexão (n= 12), grau de inchamento (n= 3), temperatura de transição vítrea (n= 3) e degradação em solvente (n= 5) foram avaliados de cada resina adesiva. Em adição foi avaliado com calorimetria exploratória diferencial (DSC), o processo de polimerização das resinas experimentais (n= 3), bem como dos homopolímeros componentes, BisGMA, HEMA, HEAA, HEMA* sem adição de etil 4- dimetilaminobenzoato (EDAB) e HEAA* sem adição de EDAB. Os resultados foram analisados estatisticamente com auxílio de ANOVA de uma via, teste de Tukey e teste t pareado. Todas as resinas adesivas e homopolímeros, exceto HEMA, HEAA* e HEMA*, apresentaram uma alta taxa de polimerização e um alto grau de conversão. Não houve diferença estatística entre as resinas adesivas para a temperatura de transição vítrea e a degradação em solvente (p>0,05). Entretanto, o grupo GHEAA33% apresentou a menor variação de grau de inchamento (p<0,05) e os menores valores de resistência à flexão (p<0,05) quando comparado com o grupo GHEMA. Considerando que a hidroxietil acrilamida foi capaz de promover o aumento do processo de polimerização de resinas adesivas experimentais e, tendo em vista sua potencial resistência à degradação hidrolítica e ainda, com base nos resultados dos demais ensaios, o grupo GHEAA33%, parece reunir as melhores condições de desenvolvimento de resinas adesivas inovadoras. / The purpose of this study was to develop an experimental adhesive resin using hydroxyethyl acrylamide (HEAA). Three groups of experimental resin were formulated, GHEAA33% (33.3% HEAA + 66.6% Bisphenol A glycerolate dimethacrylate- BisGMA), GHEAA50% (50% HEAA + 50% BisGMA), and GHEMA (33.3% 2-Hydroxyethyl methacrylate- HEMA + 66.6% of BisGMA). Parameters such as flexural strength (n= 12), swelling degree (n= 3), glass transition temperature (n= 3), and softening in solvent (n= 5) were evaluated for each adhesive resin. In addition, the polymerization process of each adhesive resin group (n= 3), as well as for the homopolymers, BisGMA, HEMA, HEAA, HEMA* without ethyl 4-dimethylaminobenzoate (EDAB), and HEAA* without EDAB, were also evaluated using differential scanning calorimetry (DSC). The results were analyzed using one way ANOVA, Tukey’s test, and Student’s t-test. For all of the resins and homopolymers evaluated, except for homopolymers HEMA, HEMA* and HEAA* homopolymer, a high rate of polymerization and a high degree of conversion were observed. There was no significant difference (p > 0.05) for the glass transition temperature and for softening in solvent for the adhesive resins assayed. In contrast, the GHEAA33% group exhibited less swelling degree (p < 0.05) and reduced flexural strength (p < 0.05) compared to the GHEMA group. HEAA was also found to promote the polymerization process and was resistant to hydrolytic degradation. Thus, GHEAA33% appears to be a promising alternative for the production of innovative adhesive resins.

Hipersensibilidade dentinária (HSD) é caracterizada como uma dor dentária curta e aguda, causada em resposta a estímulos térmicos, evaporativos, táteis ou osmóticos, e que não pode ser atribuída a qualquer outro tipo de patologia. A epidemiologia da HSD ainda é pouco estuda em nível populacional. O objetivo desta dissertação foi abordar a epidemiologia da HSD através da revisão crítica da literatura e da apresentação de um estudo de base populacional sobre prevalência, extensão e indicadores de risco para essa condição.Uma amostra representativa de 1023 habitantes adultos, com mais de 35 anos de idade, residentes em Porto Alegre foi obtida através de uma amostragem probabilística proporcional estratificada de múltiplo-estágio. Os participantes do estudo responderam a um questionário estruturado a respeito de dados sociodemográficos e comportamentais e receberam um exame clínico para diagnóstico de HSD térmico (jato de ar) e tátil (sonda) aplicados na superfície vestibular de todos os dentes presentes. Comandos analíticos que consideram a amostra complexa foram utilizados para gerar estimativas em modelos de risco multivariados. Aproximadamente um terço da população foi diagnosticada com HSD (jato de ar = 33,4% / sonda = 34,2%). Dentre os indivíduos que apresentaram HSD, em média 2 a 3 dentes apresentaram HSD. Os dentes mais afetados com HSD foram pré-molares superiores, molares superiores e pré-molares inferiores. Recessão gengival foi fator determinante para a ocorrência de HSD e foi modelada separadamente das demais variáveis. Mulheres, indivíduos mais jovens, fumantes, de melhor nível educacional e aqueles que relatam tratamento periodontal tiveram significativamente mais chance de HSD. Conclui-se que a prevalência e de HSD encontrada na população estudada é alta, porém com um número pequeno de dentes afetados. A ocorrência de HSD está associada a fatores comportamentais e sociodemográficos importantes, para os quais se podem estabelecer estratégias preventivas em nível individual e populacional. / Dentine hypersensitivity (DH) is characterized by an acute and short dental pain in response to thermal, evaporative, tactile and osmotic stimuli, which cannot be attributed to any other type of pathology. The epidemiology of DH is still little studied on the population level. The aim of this thesis was to assess the epidemiology of DH by conducting a critical appraisal of the literature and presenting the findings of a population-based study about the prevalence, extent and risk indicators of this condition. A representative sample of 1,023 adult 35 years and older inhabitants of Porto Alegre was obtained using a multistage, stratified, proportional to size, probability sampling strategy. Participants answered a structured questionnaire about sociodemographic and behavioral variables and were submitted to a clinical examination to diagnose DH using a blast of air and a manual probe on the buccal surfaceof all present teeth. Analytical commands that take into consideration the complex sampling design were used to generate estimates and multivariable risk models. Approximately one third of the population was diagnosed with DH (air blast= 33.4% and probe= 34.2%). Among individuals with DH, in average 2 to 3 teeth were affected by DH. The teeth most affected by DH were maxillary premolars and molars, followed by mandibular premolars. Gingival recession was a determinant factor for the occurrence of DH and was modeled separately from the other variables. Females, younger individuals, smokers, individuals of higher education and those reporting positive history of periodontal treatment had significantly higher chances of DH. It can be concluded that the prevalence of DH found in the studied population is high, although with few teeth affected. The occurrence of DH is associated with important sociodemographic and behavioral factors for which preventive strategies may be established on individual and population levels.

Este estudo foi realizado a fim de avaliar a microdureza da dentina radicular adjacente a materiais restauradores contendo fluoretos após desafios erosivos. Foi utilizado um delineamento crossover de duas fases de 4 dias consecutivos cada. Cento e doze fragmentos de dentina bovina foram obtidos, nos quais foi confeccionada uma cavidade padronizada no centro de cada um. Estas cavidades foram restauradas aleatoriamente com cimento de ionômero de vidro (Ketac-fil) ou resina composta (Filtek Z-250). Em seguida, os fragmentos restaurados foram distribuídos aleatoriamente entre os 14 voluntários, montados em aparelhos, cada um com 4 espécimes restaurados com o mesmo material. A partir do segundo dia, metade do aparelho, com dois espécimes, foi imersa em refrigerante de limão por 90 s, quatro vezes por dia, fora da boca por 3 dias. Após um intervalo de 3 dias, fragmentos restaurados com o material ainda não utilizado foram montados no aparelho e foi iniciada a segunda fase do experimento. Após os desafios erosivos, foram realizadas as medidas da microdureza da dentina adjacente às restaurações. Independente do material empregado, os espécimes erodidos apresentaram menores valores de microdureza (p<0.0001). Com relação aos materiais restauradores, foi verificado que a dentina, nas condições deste estudo, apresentou maiores valores de microdureza quando restaurada com cimento de ionômero de vidro (p<0.0001). Sendo assim, podemos concluir que o cimento de ionômero de vidro diminui a progressão da erosão da dentina radicular adjacente à restauração. / This study sought to evaluate the microhardness of root dentine adjacent to fluoride-containing restorative materials after erosive challenge. A cross-over study was performed in two phases of 4 consecutive days each. One hundred and twelve bovine root dentine slabs were obtained, and standardized box-shaped cavities were prepared at center of each specimen. The prepared cavities were randomly restored with glass-ionomer cement or composite resin. The slabs were randomly assigned among 14 volunteers, which wore intraoral palatal device containing 4 restored root dentin slabs. Starting on the second day, half of the palatal acrylic devices were immersed extraorally in a lemonade-like carbonated soft drink for 90 seconds, four times daily for 3 days. After 3-day wash-out, dentine slabs restored with the alternative material were placed into palatal appliance and the volunteers started the second phase of this study. After erosive challenges, microhardness measurements were performed. Regardless of the restorative material employed, eroded specimens demonstrated lower microhardness value (p<0.0001). At any given dentine condition examined in this study, dentine restored with glass-ionomer cement showed higher microhardness values (p<0.0001). It may be concluded that the glass-ionomer cement decreases the progression of root dentine erosion at restoration margin.