In Malaysia, the public water supply has been artificially fluoridated since 1972 at an optimum level of 0.7 ppm fluoride as a public health measure to control dental caries. However, concerns arose that a fluoride concentration of 0.7 ppm was too high given increasing exposure to other sources of fluoride. That prompted a downward adjustment of the fluoride concentration from 0.7 to 0.5 ppm in 2005. In addition to Malaysia, there has recently been a movement towards the downward adjustment of fluoride concentration in the water in the United States, Hong Kong, Singapore and Ireland. However, little is known about the impact of such adjustments on oral health. This thesis aimed to evaluate the outcome of the downward adjustment of fluoride concentration in the Malaysian public water supply from 0.7 to 0.5 ppm in relation to dental fluorosis and dental caries. Two projects were conducted. The first project comprised a systematic review to critically appraise the literature on stopping the addition of fluoride or reducing the level of fluoride in public water supply on dental caries and fluorosis. This review highlighted the gaps in knowledge and several methodological issues such as lack of examiner blinding and control of confounders. The second project was a cross sectional survey involving life-long residents aged 9 and 12 year-olds in fluoridated and non-fluoridated areas in Malaysia (n=1155). In the fluoridated area, children aged 12 years and 9 years were exposed to 0.7 and 0.5 ppmF respectively at the times when maxillary central incisors enamel developed. Fluoride exposures were assessed by questionnaire. Standardized photographs of maxillary central incisors were blind scored for fluorosis using Dean’s Index. Caries prevalence was examined using ICDAS-II criteria. The key findings indicated that the change in fluoride iv level from 0.7 to 0.5 ppm has reduced fluorosis and maintains caries preventive effect. The change in fluoridation concentration has also had a significant impact on caries prevalence at different thresholds of severity. The findings support the policy initiative of a lower fluoride concentration in the Malaysian public water supply. It also highlights the need for modification of oral health advice with regards to fluoride exposure in maximising caries prevention while minimising fluorosis.

Mechanically ventilated (MV) patients are at risk of ventilator-associated pneumonia. During mechanical ventilation, it has been proposed that the mouth becomes colonised by respiratory pathogens (RP) and the endotracheal tube (ETT) facilitates leakage of oropharyngeal secretions to the lower airways, whilst also supporting a biofilm. These are likely contributory risk factors for VAP. This research aimed to further establish the relationship between oral microorganisms and RP in colonisation of dental plaque and ETT biofilms. The study also investigated intervention strategies to limit RP colonisation. The microbial composition of dental plaque, ETT biofilms, and non-directed bronchial lavages (NBLs) from MV patients was characterised using culture and molecular approaches. RPs were frequently present at all these sites, with oral microorganisms also occurring in ETTs and NBLs. Isolates from these sites in a single patient also were determined to be the same strains based on molecular typing. Additionally, NGS showed no significant difference between dental plaque and ETT biofilm microbiomes. In vitro biofilms revealed that oral microorganisms increased RP colonisation and associated gene expression in biofilms. In in vivo studies, toothbrushes and foam swabs were found to be equally efficient at removing dental plaque and improving oral hygiene in MV patients. In vitro investigation found Chlorhexidine to be the most effective mouthwash in combatting ETT biofilms, despite high tolerance by P. aeruginosa. No difference between ETT biomaterials in supporting biofilms was evident. The work highlights the importance of dental plaque as a reservoir of RP in MV patients, and these RP also colonise ETT biofilms. The synergistic effect of oral microorganisms in promoting RP colonisation reinforced the need to adequately manage oral care in MV patients. For the first time, equal effectiveness of achieving improved oral care by toothbrushes and foam swabs was demonstrated.

The main object of this work is to determine the chemical composition of teeth of good structure and of varying degrees of hypoplasia, in order that the question of the relationship between chemical composition and hypoplasia may be considered. The term hypoplasia is here used in the sense intended by Mellanby (1923-34), who has already established a relation between the histological structure and the hypoplasia exhibited, with the susceptibility to dental caries. The chemical composition of teeth appears to have aroused little interest until the end of the nineteenth century, when analyses were made by Berzelius, followed by Hoppe-Seyler, Von Bibra and others. These workers all agree that calcium and phosphorus are the main constituents of teeth and bone, but apart from this their analyses differ considerably. The greater part of the work since 1900 has been concentrated on two problems: the nature of the calcium compound and the amount of organic substance present. The general opinion was that the calcium occurred chiefly in combination with the phosphorus. As early as 1862, Hoppe-Seyler noticed that the calcium and phosphorus ratio in bones and teeth corresponded very nearly with that for apatite.

The purpose with this in-vitro study is to examine the difference in marginal and internal gap width between bis-acryl composite resins (Luxatemp Fluorescence) and IPS Empress crowns. A maxillary left first phantom Frasaco molar tooth placed in a maxillary Frasaco model was prepared for an all-ceramic crown. 15 provisional Luxatemp crowns were made and silicon replicas of the intermediate space between the prepared tooth and the inside of the Luxatemp crowns were made to measure the internal and marginal gap width. The silicon replicas were divided into four pieces and the gap width was measured at 240 points under microscope. The results were compared to data on internal and marginal gap width for an IPS Empress crown from a published study. The results of this present study showed a slight difference in marginal and internal gap width between the Luxatemp crowns and the IPS Empress crowns (control). The Luxatemp crowns have a slightly minor overall gap width than the IPS Empress crowns. The marginal and occlusal gap width was slightly wider for the Luxatemp crowns (205µm) than for the IPS Empress crowns (170µm). The conclusion of this study is that provisional materials made of bis-acryl composite resins give a marginal and internal fit that can be compared to the marginal and internal fit of an IPS Empress crown.

The clinical knowledge and skills of dental students attending to different Swedish universities is constantly under discussion. In this study ten students attending their eighth semester at the Department of Odontology, Faculty of Medicine, Umea University Sweden were recruited to evaluate if it would be more challenging to prepare abutment teeth for fixed partial dentures (FPD) with the abutment teeth far apart in the dental arch. Questioning whether it is more difficult to achieve an adequate total convergence angle (TOC) for FPD with abutment teeth closer to each other than one with them further apart. The hypothesis that teeth further apart give a larger TOC. For the experiment the students used dental mannequins with plastic maxillae and plastic teeth provided by the simulation clinic at the university. Their task was to prepare for two separate FPD, one with the abutment teeth 14; 16 and a second 21; 13; 15. After preparation, the teeth were drilled and had metal posts placed in them, the posts representing a normal that the TOC could be measured against. Still photos of the plastic maxillae were taken using the program Shape 3D Viewer. A tangent was drawn to measure the TOC. An adequate TOC for crown retention was considered: 10-22 degrees in both mesio-distal and bucco-palatinal plane axis. The results for the two tested models of FPD were relatively similar, likely because the students got to practice preparation for the shorter and FPD first. In conclusion, this study showed no noteworthy difference between the first and second FPD preparation.

Introduction Modern society is passionate about beauty and aesthetics. According to a 2016 survey by the International Society of Aesthetic and Plastic Surgery, the demand for aesthetic surgery is more than ever. People’s perception and awareness of facial aesthetics has increased. Orofacial cleft is the most common facial dysmorphology, with prevalence about 1.46:1000 in Scotland. The aim of the initial surgical repair of cleft lip is to improve facial aesthetics and function, without interrupting facial growth. Nevertheless, facial asymmetry is a stigma in cleft patients, and revision surgery due to a patient or their parents’ dissatisfaction with the outcomes is not uncommon. Objective evaluation of facial asymmetry after primary surgical repair is valuable. It is an indication of the success of surgery, and it informs the surgeon of the magnitude and location of residual asymmetry. The evaluation of facial asymmetry has evolved significantly from landmark-based assessment to surface-based analysis. The latter provides a comprehensive evaluation of facial asymmetry by superimposing the original 3D model on its mirror copy. This permits the quantification and the visualisation of the disparity between the two halves of the face. Many studies evaluated facial asymmetry a few years after primary surgical repair. Longitudinal monitoring and quantifying of facial shape changes can potentially guide the surgeon to the optimal surgical technique. Only a few studies evaluated facial asymmetry before and after primary surgery, and their analysis was dependent on a set of facial landmarks that did not describe the asymmetry of facial surfaces between these landmarks. Unfortunately, the existing literature does not provide comprehensive longitudinal evaluation of facial asymmetry of cleft patients, and the impact of facial expression on residual facial asymmetry has not been fully investigated. Aim The aim of this study was the longitudinal evaluation of facial asymmetry of UCLP patients using an advanced facial analysis tool, and to compare the postoperative residual asymmetry with the control group. The study was carried out to assess the impact of growth and facial expression on residual facial asymmetry. Methodology This study was carried out on 30 UCLP patients. All the patients were Caucasian and underwent the same surgical protocol, which was carried out by the same surgeon at the Royal Hospital of Sick Children, Edinburgh. 3D facial images were captured for the patients, before surgery, at about 4 months after surgery and at four-year follow-up, at rest and at maximum smile using 3dMDface system. Historical data of 70 3D facial images of six-month-old non-cleft infants were also analysed in this study. Facial asymmetry was evaluated using a generic mesh. A generic facial mesh is a mathematical facial mask that consists of 7,190 vertices. The mesh was conformed on each 3D facial image. The conformed meshes were utilised to evaluate facial asymmetry using two methods: the average asymmetry, the total and regional facial asymmetry. The average asymmetry method involved the creation of four average faces for cleft patients: an average preoperative face, an average postoperative face, and two average faces at the four-year follow-up (one at rest and one at a maximum smile). The fifth average face was that of six-month-old non-cleft infants. A mirror copy for each average 3D facial model was created by reflecting it on a lateral arbitrary plane. The original and mirror models were superimposed, the absolute distances between corresponding points on the two surfaces were calculated and analysed in three directions (mediolateral, vertical and anteroposterior), to quantify facial asymmetry. The results were displayed in colour-coded maps. Asymmetry scores were obtained by calculating the median of the absolute distances between corresponding points for the total face, upper lip and nose. The asymmetry scores in the mediolateral, vertical and anteroposterior directions were also quantified. Statistical tests were applied to detect significant differences in asymmetry scores of the total face and each facial region between study groups (before surgery, after surgery and at four-year follow-up), and between surgically managed cleft group and the control group. The correlations of asymmetry scores of the total face, nose and upper lip before surgery, after surgery and at four-year follow-up were also investigated. Results Facial asymmetry in cleft patients was dramatically improved after surgery. However, the postoperative residual asymmetry of UCLP patients was significantly higher than the non-cleft infants in the three directions. Furthermore, facial asymmetry increased during growth, with main impact on the nose. Facial expressions accentuated the residual asymmetry. Specifically, there was considerable shifting of the upper lip toward the scar tissue of the affected side. The residual asymmetry of the nose at the four-year follow-up was correlated to initial nasal asymmetry and residual nasal postoperative asymmetry. The anteroposterior deficiency of the upper lip, nose and paranasal area was pronounced in the cleft group at all time intervals due to insufficient bony support of the cleft maxilla. Conclusions Cleft patients and their parents should be informed of the likelihood of residual asymmetry following surgery. Refinements in primary surgery are necessary. The superficial and deep fibres of the orbicularis muscle have to be accurately repaired according to the direction of the muscle fibres to avoid the shifting of the philtrum of the upper lip toward the scar tissue on the affected side. The orbicularis oris muscle has to be adequately dissected and rotated in the downward direction to eliminate the residual vertical deficiency at the corner of the mouth on the affected side. An incision in the internal lateral side of the nose should be considered to reduce this deficiency. The levator labii superioris alaeque nasi muscle of the cleft side has to be reflected and sutured to the corresponding muscle fibres on the other side, to avoid the residual shifting of the nose to the non-cleft side, and to eliminate the residual vertical deficiency of the alar base on the cleft side during smiling. Revision surgery should be delayed until completion of growth. Before lip revision surgery, it is necessary to evaluate the residual asymmetry when the face is at rest and during facial expressions. Consideration should be given to initial nasal asymmetry and residual postoperative nasal asymmetry. Patients should be informed about the expected need for revision surgery including rhinoplasty. We were able for the first time to quantify facial asymmetry in three directions which provided an insight into the cause of the residual facial asymmetry at rest and at maximum smile. The generic mesh is an innovative tool for the assessment of facial asymmetry.

Orientador: Jose Roberto Lovadino / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba / Made available in DSpace on 2018-08-04T20:06:01Z (GMT). No. of bitstreams: 1 Fragoso_LarissaSilveiradeMendonca_M.pdf: 745321 bytes, checksum: 11d0220042f028180b3a2d86a37f5f8b (MD5) Previous issue date: 2005 / Resumo: O objetivo deste estudo in vitro foi avaliar a influência de selantes de superfície na microinfiltração em dentes restaurados com resina composta; Foram utilizados 45 fragmentos de dentes incisivos bovinos onde foram realizados preparos cavitários do tipo Classe V. Os preparos foram restaurados com resina composta Z250, em seguida, foram armazenados em água destilada e mantidos em estufa a 37°C por 24 horas, e então, realizado acabamento e polimento. Após este procedimento, as restaurações foram divididas aleatoriamente em três grupos: grupo I (sem selamento) - controle; grupo II - as restaurações foram condicionadas e o sei ante de superfície Fortify (Bisco) foi aplicado na superfície da restauração; grupo m - as restaurações foram condicionadas e o selante de superfície Biscover (Bisco) foi aplicado na superfície da restauração. Em seguida as amostras foram armazenadas em água destilada por mais 12 horas a 37°C e submetidas à termociclagem. Para avaliar a infiltração marginal, as restaurações foram imersas em corante tamponado de azul de metileno 2%, por 4 horas. O método utilizado para a avaliação foi o qualitativo, por meio de um Estereomicroscópio onde três observadores calibrados avaliaram o nível de infiltração do corante na interface dente/material restaurador de acordo com os seguintes escores: 0= nenhuma infiltração do corante; 1= infiltração do corante na interface dente/restauração, até a metade da parede gengival; 2= infiltração do corante na interface dente/restauração, além da metade da parede gengival, sem atingir a parede axial; 3= infiltração do corante ao longo da interface dente/restauração até a parede axial ou além dela. Os resultados obtidos foram submetidos à análise estatística (Testes de Kappa e Kruskal-Wallis). Foi demonstrado que os selantes de superfície Fortify (Grupo lI) e Biscover (Grupo III), apresentaram as menores médias de infiltração marginal, diferindo estatisticamente do grupo controle (Grupo I). Desta forma, concluiu-se que o uso de selantes de superfície foi eficaz na diminuição da infiltração marginal / Abstract: The aim of this "in vitro" study was to evaluate the influence of sealants on the microleakage of teeth restored with composite. Class V cavity preparations were performed in 45 bovine incisive fragments. The cavities were filled with composite resin Z250. They were then stored in distilled water and placed in a incubator at 37°C for 24 hours followed by finishing and polishing. After this procedure, the samples were randomly divided into 3 groups: Group I (no sealant) - control; Group II- Samples were etched and the surface sealant Fortify (Bisco) was applied over the filling's surface; Group m- Samples were conditioned and Biscover (Bisco) was applied over the filling's surface. In a second moment, the fillings were stored once more in distilled water for 12 hours at 37°C and then were submitted to thermocyc1ing. To evaluate marginal infiltration, the samples were immersed in 2% methylene blue dye (pH 7,0), for 4 hours. The method used for evaluation was qualitative, through the manipulation of an Estereomicroscope where three observes analyzed the infiltration leveI of the pigment within the tooth/filling according the following scores: 0= no infiltration; 1= infiltration within tooth/material interface, beyond half of the gingival wall; 2 = infiltration within tooth/material interface, beyond half of the gingival wall, but not reaching the axial wall; 3 = infiltration within tooth/material interface up to or beyond axial wall. The results obtained were submitted to statistical analysis (Kruskal-Wallis Test). 1t was demonstrated that the surfaces sealantes Fortify (group II) and Biscover(group m) presented the lowest averages of marginal infiltration, and these results were statistically significant in relation to group control (group I). 1t can be conc1uded that the use of surface sealant was eficient on reducting the microinfiltration / Mestrado / Dentística / Mestre em Clínica Odontológica

Orientador: Cláudia Herrera Tambeli / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba / Made available in DSpace on 2018-08-22T18:55:08Z (GMT). No. of bitstreams: 1 Lamana_SimoneMonalizaSilva_M.pdf: 1118218 bytes, checksum: ec0ea22810a00d9896728f018c3fef06 (MD5) Previous issue date: 2013 / Resumo: A resposta de imobilidade dorsal é um comportamento defensivo inato, caracterizado por um estado temporário de profunda e reversível inibição motora, induzido por algumas formas de restrição física. Quando um animal está em uma situação de perigo ele apresenta comportamentos defensivos para tentar assegurar sua sobrevivência. No entanto, não se sabe se a hiperalgesia inflamatória persistente (HIP) poderia afetar o comportamento defensivo de imobilidade dorsal (CDID) em ratos. Recentemente, foi demonstrado por nosso grupo de pesquisa que a dor aguda periférica, por meio da ativação de um circuito neural endógeno de modulação de dor conhecido por controle nociceptivo ascendente (ANC), potencializa a duração CDID em ratos por um mecanismo opióide-dependente no núcleo accumbens (NAc). No entanto, também não se sabe se a HIP afeta esse processo. Nesse contexto, o objetivo do presente estudo foi investigar se a HIP afeta a duração do CDID e a modulação que a dor aguda periférica intensa, via ativação do ANC, exerce neste comportamento defensivo. A HIP foi induzida por um modelo experimental no qual a hiperalgesia dura por aproximadamente 30 dias após o término da administração diária de prostaglandina E2 no tecido subcutâneo da pata traseira de ratos por 14 dias. O CDID foi induzido através da suspensão do rato adulto pela pele da nuca. Para investigar se a HIP afeta o CDID, este foi avaliado nos dias 1, 7 e 14 de administração de prostaglandina E2 (período de indução da HIP) ou seu veículo no tecido subcutâneo da pata traseira de ratos e nos dias 1, 7, 14 e 21 após a interrupção do tratamento com a prostaglandina E2 (período de manutenção da HIP). Para investigar se a HIP afeta a modulação que a dor aguda periférica intensa, via ativação do ANC, exerce sobre o CDID, a capsaicina foi administrada subcutaneamente na pata dianteira para induzir estimulação nociceptiva periférica e ativar o ANC nos dias 1, 7, e 14 de administração de PGE2 e nos dias 1, 7, 14 e 21 após a interrupção do tratamento com a PGE2. Dez minutos antes da administração de capsaicina o antagonista do receptor opióide ?, CTOP ou seu veículo, foi administrado no NAc e imediatamente após a administração da capsaicina, foi avaliado o CDID e a atividade locomotora dos ratos no equipamento Rota-rod. Os resultados demonstram, pela primeira vez, que a HIP reduz a duração do CDID em ratos em ambos os períodos de indução e manutenção da HIP. Além disso, demonstram que a estimulação nociceptiva periférica intensa, via ativação do ANC, aumenta a duração do CDID em ratos durante os períodos de indução e manutenção da HIP, efeito que é prevenido pela administração prévia do antagonista de receptor opióide ?, CTOP (Cys2, Tyr3, Orn5, Pen7amide) intra-NAc. Esses resultados sugerem que a HIP reduz a duração do CDID, mas não afeta a capacidade de mecanismos endógenos de modulação de dor, como o ANC, em facilitar comportamentos defensivos / Abstract: The dorsal immobility response is an inborn defensive behavior characterized by a temporary state of profound and reversible motor inhibition induced by some forms of physical restraint. When the animal is in a dangerous situation it needs to engage in defensive responses without interference from the motivational conflicts to engage in recuperative behaviors. However, it is unclear whether the persistent inflammatory hyperalgesia (PIH) could affect the defensive behavior of dorsal immobility (DBDI) in rats. Recently, our research group has demonstrated that acute peripheral pain through activation of endogenous neural circuitry of pain modulation known for ascending nociceptive control (ANC), enhances the duration of the DBDI in rats through a mechanism opioid-dependent on the nucleus accumbens (NAc). Moreover, the PIH could be the conflict source. Based on this, the proposal of the present study was to investigate whether PIH affects the DBDI and the modulation that intense acute peripheral pain, via ANC activation, exerts on this defensive behavior. The PIH was induced by using an experimental model in which hyperalgesia lasting for about 30 days after the daily administration of prostaglandin E2 (PGE2) for 14 days in the subcutaneous tissue of the rats' hind paw. The DBDI was induced by suspending the adult rat the skin of the nape. Investigating whether PIH affects the DBDI, immobility dorsal behavior was evaluated on days 1, 7, and 14, prostaglandin E2 (induction period of PIH) or its vehicle in the subcutaneous tissue of the rats' hind paw and on days 1, 7, 14, and 21 after cessation of treatment with prostaglandin E2 (maintenance period of PIH). Investigating whether PIH affects modulation of the intense peripheral acute pain, via activation of ANC, carries on the DBDI, capsaicin was administered subcutaneously in the fore paw to induce peripheral nociceptive stimulation and activate the ANC on days 1, 7, and 14 prostaglandin E2 and on days 1, 7, 14, and 21 after discontinuation of PGE2. Ten minutes before administration of the capsaicin ?-opioid receptor antagonist, CTOP, or its vehicle was administered in the NAc and immediately after administration of capsaicin, the dorsal immobility response was evaluated, and the locomotor activity of the animals in the equipment Rota-rod. The results demonstrate for the first time that PIH decreases the duration of DBDI in rats in both induction and maintenance periods of PIH. They also show that intense peripheral nociceptive stimulation via activation ANC increases the duration of dorsal immobility response in rats during periods of induction and maintenance of PIH, and that this effect is prevented by the prior intra-accumbal administration of the ?-opioid receptor antagonist, CTOP (Cys2, Tyr3, Orn5, Pen7amide). These results suggest that PIH affects the DBDI, by reducing its duration, but does not affect the ability of endogenous pain modulation mechanisms, such as the ANC, to facilitate defensive behaviors / Mestrado / Fisiologia Oral / Mestra em Odontologia

Orientador: Giselle Maria Marchi Baron / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba / Made available in DSpace on 2018-08-19T23:13:34Z (GMT). No. of bitstreams: 1 Delicio_GiovanaPriscila_M.pdf: 2334364 bytes, checksum: 71a46a0afbbdeb4bc75c338b2352a916 (MD5) Previous issue date: 2012 / Resumo: O objetivo deste trabalho foi avaliar, in vitro, a resistência de união de pinos intrarradiculares cimentados através de diferentes protocolos adesivos e submetidos ou não à ciclagem mecânica. Foram selecionadas 80 raízes de incisivos inferiores bovinos com dimensões semelhantes, as quais foram incluídas em resina de poliestireno. Os corpos-de-prova foram separados em 10 grupos experimentais (n=8), de acordo com o protocolo adesivo realizado, sendo que 8 amostras de cada protocolo foram submetidas à fadiga mecânica e 8 não. Os protocolos adesivos realizados estão descritos a seguir: Grupos 1 e 6 - cimento resinoso RelyX Unicem; Grupos 2 e 7 - cimento resinoso RelyX Unicem com prévio condicionamento ácido e aplicação do sistema adesivo Adper Single Bond; Grupos 3 e 8 - cimento resino Panávia F 2.0 e sistema adesivo autocondicionante Clearfil SE Bond + ED Primer; Grupos 4 e 9 - cimento resinoso RelyX ARC e sistema adesivo Scothbond Multi Purpose Plus; Grupos 5 e 10 - cimento resinoso Panavia F 2.0 e sistema adesivo ED Primer. Após a cimentação dos pinos pré-fabricados, foram confeccionados núcleos de preenchimento de resina composta. Foram aplicados 200.000 ciclos, com força axial intermitente de 80N (1Hz). O teste de push-out foi realizado a uma velocidade de 0,5mm/min e os valores expressos em MPa obtidos de cada grupo, foram tabulados e analisados quanto à sua normalidade. Após isso, foi realizada a análise de variância (ANOVA) e teste Tukey. Segundo os resultados, os cimentos Unicem e Panávia aplicados conforme as instruções do fabricante, apresentaram os menores valores de resistência de x união, não havendo diferença significante entre os demais protocolos adesivos. Além disso, não observou-se diferença estatisticamente significante entre os grupos submetidos e os não submetidos à fadiga mecânica. Segundo esta pesquisa, pode-se concluir que a aplicação de novos protocolos adesivos pode ser viável no sucesso clínico da cimentação de pinos de fibra de vidro no canal radicular uma vez que trouxeram vantagens na resistência de união avaliada / Abstract: The objective of this study was to evaluate in vitro the bond strength of intracanal posts cemented using different adhesive protocols and not submitted to mechanical cycling. 80 roots were selected from bovine incisors with similar dimensions, which are included in polystyrene resin. The bodies of the test piece were divided into 10 experimental groups (n = 8), in accordance with the adhesive protocol performed, with each protocol eight samples were subjected to mechanical stress and not 8. The adhesive protocols performed are as follows: Groups 1 and 6 - cement RelyX Unicem; Groups 2:07 - cement RelyX Unicem with prior etching and application of the adhesive system Single Bond; Groups 3:08 - Resino cement Panavia F 2.0 and etching adhesive system Clearfil SE Bond Primer + ED; Groups 4:09 - RelyX ARC resin cement and adhesive system Scothbond Multi Purpose Plus; Groups 5:10 - Panavia F 2.0 ED primer and adhesive system. After cementation of prefabricated posts, cores were made of composite resin filling. 200,000 cycles were applied, with intermittent axial force 80N (1Hz). The push-out test was carried out at a speed of 0.5 mm / min and the values expressed in MPa obtained from each group were tabulated and analyzed for their normal. After this, we performed analysis of variance (ANOVA) and Tukey's test. According to the results, Unicem and Panavia cements applied according to manufacturer's instructions, had the lowest bond strength, no significant difference between the protocols other adhesives. In addition, there was no statistically significant difference between the groups submitted and not submitted to mechanical fatigue. According to this research, the implementation of new protocol designs can be feasible in the clinical success of the cementation of fiber glass in the canal since it brought advantages in bond strength evaluated / Mestrado / Dentística / Mestre em Clínica Odontológica

Orientador: Luis Roberto Marcondes Martins / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba / Made available in DSpace on 2018-08-20T01:21:28Z (GMT). No. of bitstreams: 1 Fabiao_MayradeMello_M.pdf: 6929513 bytes, checksum: ce29eeaf520ef3d3786cf99b82f39197 (MD5) Previous issue date: 2012 / Resumo: O objetivo deste estudo foi avaliar a resistência de união ao microcisalhamento de três cimentos resinosos (RelyX ARC, RelyX U100 e Panavia F), com diferentes protocolos adesivos estabelecidos para cada cimento e unidos a dois tipos de cerâmica (feldspática - d.SIGN e dissilicato de litio - e.max) através da fotopolimerização transcerâmica. Em adição foi avaliado o grau de conversão dos grupos em estudo. Para resistência de união, apos a aplicação dos adesivos, foram confeccionados cilindros de cimento para a realização do teste de microcisalhamento (n=8) em máquina de ensaio universal. A fotopolimerização foi realizada com aparelho de luz halógena por 60 segundos através da cerâmica com o auxilio de um dispositivo confeccionado para o presente estudo. Apos os ensaios, as amostras fraturadas foram analisadas em microscópio eletrônico de varredura para a classificação do padrão de fratura. Para analise do grau de conversão, os cimentos foram manipulados e inseridos em molde. Os diferentes protocolos adesivos foram aplicados em uma tira de poliéster, posicionados sobre o cimento e fotopolimerizados através da um disco de cerâmica de acordo com o grupo (n=5) A leitura do grau de conversão foi alizada através de espectofotometria. Os dados obtidos para ambos os experimentos foram analisados estatisticamente através de ANOVA 2-- critérios e teste de Tukey (p? 0,05). A resistência de união e o grau de conversão foram influenciados pelo tipo de cerâmica utilizada. As amostras fotopolimerizadas através da cerâmica feldspática apresentaram resultados superiores do que as polimerizadas através da cerâmica reforçada. RelyX ARC obteve os maiores valores de resistência de união que os demais cimentos testados. Os valores de resistência de união e grau de conversão dos cimentos testados foram influenciados pelos protocolos adesivos na ausência de intensidade de luz adequada / Abstract: The aim of this study was to evaluate the micro shear bond strength of three resin cements (RelyX ARC, RelyX U100 and Panavia F), with differente adhesive protocols and two ceramic types (feldspatic - d.SIGN and lithium dissilicate reinforced - e.max) photocured through ceramic. In addition it was measured the degree of conversion of each group. For bond strength test, the adhesives were applied in the ceramic surface, and the resin cement cylinders were confectioned for the micro--?shear bond strength test (8 specimens with 4 cylinders for each group). A device was developed to permit light cure through ceramic. Fractures specimens were SEM analyzed to classify the failure mode. For DC analysis, the resin cements were manipulated and applied into a mold. The adhesive protocols were performed on a Mylar strip and positioned upon the manipulated cement. A ceramic disc respective to each group was placed above the Mylar strip and the light curing was performed (n=5). Data were statistically analyzed (p?0.05) using a two--way ANOVA and Tukey ?s test. Feldspatic ceramic presented better results than lithium dissilicate reinforced ceramic for both methodologies. RelyX ARC presented higher bond strength values than the other cements. Different adhesive protocols significantly affect bond strength and DC values in abcense of adequate ligth intensity / Mestrado / Dentística / Mestre em Clínica Odontológica