A study was made of three groups of materials used in dentistryq i. e. denture base acrylics, "Gel-type" tissue conditioners and epimine resins. Conventional denture base acrylic made by curing a dough of methyl methacrylate and poly(methyl methacrylate) beads is considerably weaker than homogeneous poly(methyl methacrylate). The reasons for this were revealed by a comparison of their fracture mechanics and morphology. Phase inhomogenuity was found in denture base acrylic, the interstitial phase having lower Mv and Young's modulus than the bead phase. A viscoelastic and autoradiographic study of the denture base acrylic revealed that the two phases were interpenetrating polymer networks. It was found possible to improve the strength of denture base acrylic by the addition of methacrylic acid thus improving the 19 v of the interstitial polymer. The combination of methacrylic acid and cross-linking agent also facilitated the control of phase stiffness. Improving the molecular weight and matching the phase stiffness produces a conventional denture base material of comparable strength to homogeneous poly(methyl methacrylate)o A study of the effects on "Gel-type" tissue conditioners of an oral environment revealed the reasons for their loss of compliance during clinical use. The alcohol desorption and water absorption characteristics of the gels were studied. prom such studies and a knowledge of their chemical composition conclusions were drawn regarding the best ccr. positions for tissue conditioner gels intended for long service in the mouth. Two epimine ccnpounds, an impression rubber and a temporary crown and bridge material were studied. Their physical properties and chemical composition were determined. A car. parison of known long term behaviour of analogous resins; canbined with the determined physical properties of the epimine resins studiedt revealed some of the clinical limitations of such systems.

Apesar dos pesquisadores afirmarem que os materiais odontológicos restauradores, devido às suas diferentes propriedades mecânicas, influenciam na transmissão da carga para os tecidos de suporte, não foi encontrada comprovação científica concludente. Os trabalhos de análise da distribuição da carga oclusal com diferentes materiais de reconstrução protética não são concordantes em seus resultados. Assim, diante da importância da seleção de materiais restauradores protéticos no prognóstico da reabilitação oral, este trabalho se propôs a estudar a influência de coroas protéticas metalo-cerâmica e de resina, cimentadas no canino, na transmissão de tensões para o tecido ósseo em mandíbulas frescas de cães, utilizando o método de interferometria holográfica de dupla exposição. Seis hemi-mandíbulas frescas de cães da espécie Canis familiares foram fixadas em um dispositivo para garantir a invariabilidade da força aplicada durante o experimento. Uma carga de 0,98 N foi aplicada sobre as coroas, seguindo o longo eixo do dente. Pelo método de interferometria holográfica, foram obtidos 12 hologramas, 6 para cada grupo de amostras. As coroas metalo-cerâmicas apresentaram maior deslocamento, com movimento de intrusão no alvéolo, em relação às de resina. Os microdeslocamentos resultantes nas hemimandíbulas demonstraram comportamentos semelhantes de deflexão, porém, não foram encontradas diferenças estatisticamente significantes na distribuição das tensões ao osso, com relação aos dois tipos de coroas consideradas, demonstrando a influência da presença do ligamento periodontal. / Although researches assert that restoring dental material, due to their different mechanical properties, influences at load transmission to support tissues, it was not find any conclusive scientific evidence. Researches with finite element, implants and different prosthetic reconstruction material do not have an agreement in terms of results. So, considering the importance of prosthetic restoring material selection on oral rehabilitate prognosis, this assignment studied the influence of metaloceramic and resin prosthetics crowns, cemented on canine, during stress transmission to bony tissue of post-mortem dog mandibles, using double exposure holographic interferometry method. Three fresh mandibles were split into 6 hemi-mandibles, which were fixed in a proper device in order to assure the same applied force during the whole experiment. A 0,98 N load was applied to the crowns, following the long axis of the tooth. It was collect 12 holograms, 6 for each sample group. Metaloceramic crowns presented larger intrusion micromovement in the alveolus, comparing that of resin ones. The resulting micromovings in the hemimandibles presented similar deflecting behaviour. However, significant statistical differences on bone tension distribution have not been found, concerning the two types of previously referred crowns, demonstrating the influence of periodontal ligament.

Proporcionar longevidade clínica às restaurações cerâmicas deve ser um dos objetivos principais dos cirurgiões-dentistas ao realizar um tratamento protético. Objetivo: Correlacionar a influência do tratamento interno do substrato cerâmico e do tipo de polimento da superfície cerâmica externa com a efetividade clínica de restaurações com sistemas cerâmicos livres de metal. Métodos: Foram elaborados quatro artigos científicos. No Capítulo 1, apresentou-se um estudo de revisão da literatura a respeito dos métodos de tratamento de superfície para as cerâmicas reforçadas por óxido de zircônia e a implicação clínica deste procedimento na resistência da união deste sistema cerâmico quando realizada cimentação adesiva. Os Capítulos de 2 a 4 são representativos de trabalhos in vitro. No Capítulo 2, foi delineado um experimento com o objetivo de avaliar a influência do tratamento da superfície interna da cerâmica e do tipo de cimento (resinoso dual ou autoadesivo) sobre a resistência da união da interface cerâmicacimento por meio de ensaio de microcisalhamento. Os tratamentos de superfície avaliados foram: condicionamento com ácido fluorídrico a 10%, jateamento com óxido de alumínio 110μm, silicatização e junção de jateamento com óxido de alumínio 110μm e aplicação de um agente silano específicos. O teste foi realizado após o período de 24 horas e os resultados expressos em MPa. Adicionalmente, foi avaliada quantitativamente e qualitativamente a modificação promovida na superfície interna do substrato cerâmico por cada um dos tratamentos de superfície avaliados. No Capítulo 3, o mesmo delineamento executado no Capítulo 2 foi realizado, porém avaliando-se a resistência à degradação hidrolítica promovida pelos mesmos métodos de tratamento da superfície interna da cerâmica, com a realização do ensaio de resistência da união ao microcisalhamento após 24 horas e seis meses de armazenagem em água. No Capítulo 4, foi avaliada a eficácia de diferentes métodos de polimento da superfície cerâmica externa por meio de um ensaio de rugosidade de superfície e microscopia de força atômica, sendo ainda realizada a comparação entre os sistemas cerâmicos pelo ensaio de resistência à tração diametral. Conclusões: Com este trabalho foi possível determinar a importância do tratamento da superfície interna das cerâmicas previamente à cimentação adesiva, objetivando aprimorar a resistência da união da interface cerâmica-cimento, conferindo longevidade às restaurações cerâmicas. Com este propósito, para sistemas cerâmicos reforçados por zircônia, tratamentos de superfície que promovam modificações mecânicas e químicas da superfície cerâmica devem ser utilizados. Também foi possível observar que as restaurações cerâmicas depois de cimentadas e ajustadas clinicamente, devem ser submetidas a técnicas de polimento, sendo que a efetividade desta etapa é dependente da técnica de polimento executada. / Make the clinical longevity to ceramic restorations has must been a principal objective in prosthetic treatment realized for a dentist. Purpose: Correlation the influence of internal treatment in ceramic substrate and polishing method to ceramic external surface with clinical effectiveness in the metal free ceramic systems. Methods: Was elaborated four scientific articles. In the chapter one, present a literature review study with describes the treatment surface methods to ceramics reinforced to zirconium oxide and the clinical importance this procedure to the bond strength when realized adhesive cementation with ceramic system. The chapter two at four represented in vitro studies. In the chapter two, was delineated a experiment with the objective to evaluated the influence internal treatment in ceramic and the type of cement (dual cure resin and self adhesive) on the bond strength in interface ceramic-cement with microshear test. The surface treatments was: hydrofluoric acid conditioned, sandblasting using aluminum oxide 110μm, silica coating and sandblasting using aluminum oxide 110μm associated with silane agent specified. The test was performed after 24 hours and results presents in Mpa. In addition, was a quantitative and qualitatively evaluation the modification to improved in internal surface in ceramic substrate for the each surface treatment evaluated. In the chapter three, was realized the study assemble the chapter two, therefore evaluated the hydrophilic degradation improved to surface treatment internal ceramic with the microshear test after 24 hours and six months in water storage. In the chapter four, the efficacy in different polishing methods of external surface ceramic was evaluated by the surface roughness test and atomic force microscope, being even performed comparison between ceramic systems and the experiment of the diametral tensile strength. Conclusions: In this study, was possible to determinate the importance of internal surface treatment in ceramics previously adhesive cementation with objective the best bond strength in ceramic-cement interface to obtained longevity in ceramic restorations. With this objective, to ceramics reinforced to zirconium oxide, treatments surface that improve mechanical and chemistry modification to ceramic surface must be realized. Was possible too observed that ceramic restorations after cementations and clinical adjustments must be submitted the polishing techniques where the effectiveness is depended to polishing technique realized.

Apesar dos pesquisadores afirmarem que os materiais odontológicos restauradores, devido às suas diferentes propriedades mecânicas, influenciam na transmissão da carga para os tecidos de suporte, não foi encontrada comprovação científica concludente. Os trabalhos de análise da distribuição da carga oclusal com diferentes materiais de reconstrução protética não são concordantes em seus resultados. Assim, diante da importância da seleção de materiais restauradores protéticos no prognóstico da reabilitação oral, este trabalho se propôs a estudar a influência de coroas protéticas metalo-cerâmica e de resina, cimentadas no canino, na transmissão de tensões para o tecido ósseo em mandíbulas frescas de cães, utilizando o método de interferometria holográfica de dupla exposição. Seis hemi-mandíbulas frescas de cães da espécie Canis familiares foram fixadas em um dispositivo para garantir a invariabilidade da força aplicada durante o experimento. Uma carga de 0,98 N foi aplicada sobre as coroas, seguindo o longo eixo do dente. Pelo método de interferometria holográfica, foram obtidos 12 hologramas, 6 para cada grupo de amostras. As coroas metalo-cerâmicas apresentaram maior deslocamento, com movimento de intrusão no alvéolo, em relação às de resina. Os microdeslocamentos resultantes nas hemimandíbulas demonstraram comportamentos semelhantes de deflexão, porém, não foram encontradas diferenças estatisticamente significantes na distribuição das tensões ao osso, com relação aos dois tipos de coroas consideradas, demonstrando a influência da presença do ligamento periodontal. / Although researches assert that restoring dental material, due to their different mechanical properties, influences at load transmission to support tissues, it was not find any conclusive scientific evidence. Researches with finite element, implants and different prosthetic reconstruction material do not have an agreement in terms of results. So, considering the importance of prosthetic restoring material selection on oral rehabilitate prognosis, this assignment studied the influence of metaloceramic and resin prosthetics crowns, cemented on canine, during stress transmission to bony tissue of post-mortem dog mandibles, using double exposure holographic interferometry method. Three fresh mandibles were split into 6 hemi-mandibles, which were fixed in a proper device in order to assure the same applied force during the whole experiment. A 0,98 N load was applied to the crowns, following the long axis of the tooth. It was collect 12 holograms, 6 for each sample group. Metaloceramic crowns presented larger intrusion micromovement in the alveolus, comparing that of resin ones. The resulting micromovings in the hemimandibles presented similar deflecting behaviour. However, significant statistical differences on bone tension distribution have not been found, concerning the two types of previously referred crowns, demonstrating the influence of periodontal ligament.

Thesis (MPhil)--Stellenbosch University, 2011. / ENGLISH ABSTRACT: Removable Prosthetic Dentistry (PRO400) is a fourth year module of the undergraduate dentistry programme which consists of a large clinical component. After reviewing relevant literature and conducting module evaluations, clinical tests were introduced and implemented in 2008 as an additional clinical assessment method. The intention of introducing the clinical tests was an attempt to ensure that students were assessed fairly, that their theoretical knowledge and the ability to apply it clinically were properly assessed, and to provide feedback on their clinical performance. The purpose of this concurrent mixed methods study was to compare the relationship between the students‟ performance in the clinical tests and daily clinical grades with their theoretical performance in the PRO400 module. The second part of the study explored the academic staff s‟ perceptions of the clinical test as clinical assessment tool in the PRO400 module. The case study design enabled the researcher to explore the question at hand in considerable depth. The mixed methods approach was useful to capture the best of both the qualitative and quantitative approaches. For the quantitative data-collection, record reviews of the results of fourth-year dental students‟ who completed the PRO400 module at the end of 2007 were used, and included 110 students. For the qualitative component three full-time lecturers within the Prosthetic department were interviewed. The clinical test marks and clinical session marks of all the students (n=109) in PRO400 were compared to their theory mark of that year. The tests marks were entered into a spreadsheet in Microsoft Excel and the data analysis was done with the assistance of a statistician. The analytical abstraction method was used to assist with the qualitative data analysis; first the basic level of analysis was done in the narrative form, followed by second higher level of data analysis. The basic and higher levels of analysis were discussed under the following themes: clinical tests, student performances, alignment of theory and clinical assessment and personal influence on supervisors‟ assessment practices and attitude. Role-taking and the supervisors‟ perceptions and concerns regarding the students were explored as emergent themes. The quantitative findings were displayed using tables and graphs. Forty five students. clinical marks were 10% higher than their theory mark, while only 8 students. theory marks were 10% higher than their clinical test mark. There appeared to be hardly any relationship between the students. clinical daily grade assessment marks and their theory marks. The average theory mark was 47%, the average clinical test marks were 55% and the average daily clinical grade was 63%. Integration of the data obtained from the different data collection methods was done at the level of data interpretation. The clinical test as an assessment tool is well accepted by the supervisors and they agreed that it is more reliable and accurate than the clinical daily grade assessment method. The quantitative findings relate well to other reported studies that concluded that the daily grade was poorly correlated with the competency exams (a similar phenomenon in the clinical test of the PRO400 module). From the findings of this study it appeared that there is a better correlation of the clinical test mark and the theory mark, than clinical daily mark and the theory mark. This finding related well with the lecturers. views that the clinical tests were more reliable as a clinical assessment tool than the daily clinical mark. / AFRIKAANSE OPSOMMING: "Removable Prosthetic Dentistry (PRO400)" is 'n vierdejaar-module in die voorgraadse tandheelkundeprogram wat 'n groot kliniese komponent bevat. Na 'n oorsig gedoen is van die relevante literatuur, en nadat die module-evaluering afgehandel is, is kliniese toetse in 2008 ingevoer en geimplementeer as 'n bykomende metode van kliniese assessering. Die kliniese toetse is ingestel in 'n poging om te verseker dat studente se teoretiese kennis en hul vermoe om dit klinies toe te pas op . regverdige wyse geassesseer word en om terugvoer te kan gee oor die studente se kliniese prestasie. Die doel van hierdie studie, waarin gelyktydige gemengde metodes gebruik is, was om die verband tussen die studente se prestasie in die kliniese toetse, asook hul daaglikse kliniese punte en hul teoretiese prestasie in die PRO400-module vas te stel. Die tweede deel van die studie het ondersoek ingestel na die akademiese personeel se persepsies van die kliniese toets as 'n instrument vir kliniese assessering in die PRO400-module. 'n Dwarssnit-gevallestudie-ontwerp is gebruik en 'n gemengdemetode-benadering was nuttig om sowel kwalitatiewe as kwantitatiewe data in te samel. Vir die kwantitatiewe data-insamelingverslae is die uitslae van 109 vierdejaar-tandeheelkundestudente in die PRO400-module aan die einde van 2007 gebruik. Vir die kwalitatiewe data-insameling is onderhoude gevoer met drie voltydse dosente in die Prostetiese Tandheelkunde-departement. Die kliniese toetspunte en die kliniese sessiepunte van al die studente (n=109) in die PRO400-module is met hul teoriepunte van daardie jaar vergelyk. Die toetspunte is op 'n sigblad in Microsoft Excel ingevoer en die data-analise is met die hulp van 'n statistikus gedoen. Die analitiese abstraksiemetode is vir die analise van die kwalitatiewe data gebruik. Die basiese vlak van data-analise in die narratiewe vorm is eerste gedoen. Dit is gevolg deur 'n tweede, hoervlak-data-analise. Die basiese en hoer vlakke van analise is onder die volgende temas bespreek: kliniese toetse, studenteprestasie, ooreenstemming van teorie en kliniese assessering, en persoonlike invloed op studieleiers se assesseringspraktyke en houding. Rol-aanneming en die studieleiers se persepsies, asook kwessies rakende die studente is as ontluikende temas ondersoek. Die resultate van hierdie studie het aangetoon dat die kliniese punte van 45 studente 10% hoër was as hul teoriepunte, en dat slegs agt studente se teoriepunte 10% hoër as hul kliniese toetspunte was. Dit het geblyk dat daar feitlik geen verband was tussen die studente se kliniese daaglikse assesseringspunte en hul teoriepunte nie. Die gemiddelde teoriepunt was 47%, die gemiddelde kliniese toetspunt was 55% en die gemiddelde daaglikse kliniese punt was 63%. Al die studieleiers het die kliniese toets as assesseringsinstrument goed aanvaar en hulle het saamgestem dat dit meer betroubaar en akkuraat is as die daaglikse kliniese assesseringsmetode. Die kwantitatiewe bevindings hou goed verband met dié van soortgelyke studies waarin daar bevind is dat die daaglikse prestasie swak gekorreleer het met die bevoegdheidseksamen (ʼn soortgelyke beginsel as die kliniese toets van die Pro400). Dit het ook uit die bevindings van hierdie navorsing geblyk dat daar ʼn beter korrelasie is tussen die kliniese toetspunt en die teoriepunt as tussen die daaglikse kliniese punt en die teoriepunt. Hierdie bevinding het ʼn duidelike verband getoon met die dosente se siening dat die kliniese toetse as ʼn kliniese assesseringsinstrument meer betroubaar is as die daaglikse kliniese punt in die PRO400-module in die Tandheelkunde-program.

Initiativet till projektet togs av tandvårdspersonal på Specialisttandvården i Halmstad då de upplevde problem vid arbete med oral protetik. Problemet, som projektet även bygger på, innebär att komponenter tappas och på grund av gravitationen samt patientens position riskeras att inhaleras eller sväljas. Detta innebär ett stress- och orosmoment, vilket bidrar till en försämrad psykosocial arbetsmiljö för tandvårdspersonalen.   2008 infördes det statliga tandvårdsstödet i Sverige vilket innebär en reducerad kostnad för protetikingrepp som lett till att fler har råd med oral protetik. Därför blir problemet mer och mer utbrett, vilket gjort kravet på en lösning mer eftertraktad.   I projektet har dynamisk produktutveckling tillämpats med stort fokus på involvering av framtida användare. Artikelsökning, observation och enkätundersökning i genomförd produktdefinitionsfas lade grunden till projektet. Olika konceptgenererings- och utvärderingsmetoder tillämpades och födde den slutgiltiga prototypen. Under hela projektets gång har en kontinuerlig dialog och testning hos uppdragsgivarna utförts.   Detta produktutvecklingsprojekt resulterade i ett instrument som underlättar för tandvårdspersonal samt ökar säkerheten för patienten vid oral protetik. Lösningen är en specialutformad pincett som träs på skruvmejseln och fixerar komponenter. / The project was initiated by dental personnel at the Specialist dentistry in Halmstad, Sweden, because they experienced problems when working with oral prosthetics. There is a risk that components are dropped and due to gravity and the patient's position, being inhaled or swallowed. This means stress and concerns, contributing to the deterioration of the psychosocial work environment for dental personnel.   The Swedish dental State support was introduced in 2008, which gives the patient a reduced cost for dental prosthetic procedures. This allows more people to afford oral prosthetics. Therefore, the problem becomes more and more prevalent and the demand for a solution is requiered.    The project has implemented dynamic product development with a major focus on the involvement of future users. The project was based on literature reviews, observation and survey, which was performed in the product definition phase. Different concept generation methods and evaluation methods were applied and resulted in a final prototype. A continuous dialogue and testing with the clients where performed throughout the project.   This product development project resulted in an instrument that facilitates for dental personnel and increase safety for the patient during oral prosthetics. The solution is a specially designed forceps which slips onto the screwdriver and secures components.

Thesis deals with the problem of the older school age boys dental injuries in České Budějovice region. The injury means: ?sudden damage of the health by effect of external factors which exceed adaptation options of the human body?. In the sphere of dental injuries the children is the most jeopardized group of population. The most often reason for the children injuries is their imperfect stability. In case of older children and young people there are injuries mostly caused by sport. Teoretical part of my thesis is focused on definition of older school age as well as on anatomy and teeth physiology. The part of thesis also is the enumeration of dental injuries and its treatment. I also mention prosthetic dentistry and the influence of accidents on individual physical and mental health. At the end of teoretical part there is mentioned process of the injured examination, posttraumatic dental hygiene and patient nutrition after teeth accident. Research part finds with the help of questionnaire survey the kinds of dental accidents, circumstances of injuries formation and the influence of accidents on individual physical and mental health in specific age category. The questionnaire survey was evaluated and processed in grafical part of thesis. The part of thesis also is health and educational material which helps to rise the quality of dental hygiene and also contributes to the prevention of dental accidents formation of second degree students at primary schools.

O objetivo deste estudo é avaliar a influência da irradiação com laser de Er,Cr:YSGG no espaço protético de condutos radiculares preparados para a fixação de pinos em fibra de vidro reforçados (FRC Postec®), avaliando-se o comportamento de três diferentes técnicas adesivas (self-etching= Panavia F®; total-etching= Excite DSC® + Variolink II® e self-adhesive= RelyX Unicem Aplicap®). Observaram-se as orientações da norma ISO-TS 11405 para a preparação das raízes dentais unirradiculares humanas. As amostras foram separadas na altura da junção amelo-dentinaria, tratadas endodonticamente com instrumentação rotatória e seladas com técnica de condensação lateral. Foram utilizados dois tipos diferentes de pontas de safira para irradiação intracanal o axial (Z4, 400 m de diâmetro) e o radial ou side firing (RFT4, 415 m de diâmetro) com densidade de energia de 40 J/cm2. Esta densidade de energia foi obtida como parte deste experimento, analisando-se diversos parâmetros de energia com os resultados morfológicos e térmicos obtidos. Nesta densidade, obtive-se grande quantidade de túbulos dentinários abertos e variação de temperatura segura para uso clínico. Cada raiz foi irradiada em cinco movimentos circulares, de apical para cervical, com intervalo de 20 segundos, entre elas. Os FRC Postec foram cimentados imediatamente após a irradiação e divididos randomicamente em nove grupos (n=10). Cada raiz foi seccionada em 6 discos de 1 mm de espessura para ensaio do tipo push-out, para a obtenção da força máxima de ruptura, e posterior cálculo da resistência de união adesiva em função da área de superfície do núcleo deslocado, resultando na pressão em MPa. A resistência de união adesiva nos grupos irradiados foi estatisticamente superior do que os grupos controle. Foram avaliadas as diferenças na resistência de união adesiva em diferentes porções do núcleo (cervical, médio e apical), onde o sistema adesivo tipo self-adhesive (RelyX Unicem Aplicap) teve o melhor resultado para os grupos irradiados. Avaliou-se por técnica de FTIR as diferenças químicas ocorridas na dentina intrarradicular irradiada com laser de Er,Cr:YSGG, em diferentes porções (cervical, médio e apical) em função da orientação dos túbulos. Foram observadas nos espectros de FTIR alterações na intensidade das bandas de algumas moléculas, indicando variação na quantidade da parte orgânica (amida I e amida II) após a irradiação, nas diferentes regiões dentais em função do feixe laser sobre a orientação dos túbulos dentinários, sem causar alterações na sua composição. Essas diferenças podem interferir no resultado da resistência de união adesiva. A técnica de utilização de laser de Er,Cr: YSGG em dentina radicular pré-cimentação de núcleo protético aumenta a resistência de união adesiva, na dependência do cimento utilizado. / The aim of this study was to evaluate the influence of the Er,Cr:YSGG laser irradiation in the prosthetic post space before FRC Postec placement using three different adhesive systems (self-etching- Panavia F; total-etching- Excite DSC + Variolink II e self adhesive - RelyX Unicem Aplicap). According to ISO-TS 11405, sectioned at the CEJ, human dental single roots were endodontically treated with rotatory instruments and filled with gutta-percha points and sealer. Were used at 40 J/cm2 an axial Z4 laser tip (400 m diameter) and a radial (side firing) RFT4 laser tip (415 m diameter). This density of energy was experimentally determinated observing morphological changes in SEM images due to an increase range in the energy applied to dentinal root canal surface. At the length between 32 and 49 J/cm2 most of the intracanal dentinal tubules were open. The temperature increase was within the biological safe suggesting a feasible clinical use. Each root canal was irradiated five times with helicoidal movements from apical to cervical, with 20 seconds interval. FRC Postec were immediately cemented and randomly divided in nine groups (n=10). Each root canal was cut in six discs for push out test, were the maximum failure load was obtained and the bond strength was calculated as a function of post bonded area. The bond strength for the irradiated groups was superior among all control groups. The evaluation of bond strength among root region (cervical, middle and apical) was performed and differences were observed. The self-adhesive (RelyX Unicem Aplicap) system was noted superior among all irradiated groups and all regions. Chemical changes were analyzed by FTIR due to dental root portion and dentinal tubules orientation to laser beam direction. The FTIR spectra obtained indicated changes due to tubules orientation and root canal portion irradiated such as the proportion among the compositional ratio without causing chemical changes. These compositional ratio alterations may affect the bond strength results. The irradiation with Er,Cr:YSGG laser on dentinal walls of a prosthetic post space preparation before the post cementation, as suggested in this study, may increase the bond strength between the post and root canal dentin depending upon the luting cement that is used.

O objetivo deste estudo é avaliar a influência da irradiação com laser de Er,Cr:YSGG no espaço protético de condutos radiculares preparados para a fixação de pinos em fibra de vidro reforçados (FRC Postec®), avaliando-se o comportamento de três diferentes técnicas adesivas (self-etching= Panavia F®; total-etching= Excite DSC® + Variolink II® e self-adhesive= RelyX Unicem Aplicap®). Observaram-se as orientações da norma ISO-TS 11405 para a preparação das raízes dentais unirradiculares humanas. As amostras foram separadas na altura da junção amelo-dentinaria, tratadas endodonticamente com instrumentação rotatória e seladas com técnica de condensação lateral. Foram utilizados dois tipos diferentes de pontas de safira para irradiação intracanal o axial (Z4, 400 m de diâmetro) e o radial ou side firing (RFT4, 415 m de diâmetro) com densidade de energia de 40 J/cm2. Esta densidade de energia foi obtida como parte deste experimento, analisando-se diversos parâmetros de energia com os resultados morfológicos e térmicos obtidos. Nesta densidade, obtive-se grande quantidade de túbulos dentinários abertos e variação de temperatura segura para uso clínico. Cada raiz foi irradiada em cinco movimentos circulares, de apical para cervical, com intervalo de 20 segundos, entre elas. Os FRC Postec foram cimentados imediatamente após a irradiação e divididos randomicamente em nove grupos (n=10). Cada raiz foi seccionada em 6 discos de 1 mm de espessura para ensaio do tipo push-out, para a obtenção da força máxima de ruptura, e posterior cálculo da resistência de união adesiva em função da área de superfície do núcleo deslocado, resultando na pressão em MPa. A resistência de união adesiva nos grupos irradiados foi estatisticamente superior do que os grupos controle. Foram avaliadas as diferenças na resistência de união adesiva em diferentes porções do núcleo (cervical, médio e apical), onde o sistema adesivo tipo self-adhesive (RelyX Unicem Aplicap) teve o melhor resultado para os grupos irradiados. Avaliou-se por técnica de FTIR as diferenças químicas ocorridas na dentina intrarradicular irradiada com laser de Er,Cr:YSGG, em diferentes porções (cervical, médio e apical) em função da orientação dos túbulos. Foram observadas nos espectros de FTIR alterações na intensidade das bandas de algumas moléculas, indicando variação na quantidade da parte orgânica (amida I e amida II) após a irradiação, nas diferentes regiões dentais em função do feixe laser sobre a orientação dos túbulos dentinários, sem causar alterações na sua composição. Essas diferenças podem interferir no resultado da resistência de união adesiva. A técnica de utilização de laser de Er,Cr: YSGG em dentina radicular pré-cimentação de núcleo protético aumenta a resistência de união adesiva, na dependência do cimento utilizado. / The aim of this study was to evaluate the influence of the Er,Cr:YSGG laser irradiation in the prosthetic post space before FRC Postec placement using three different adhesive systems (self-etching- Panavia F; total-etching- Excite DSC + Variolink II e self adhesive - RelyX Unicem Aplicap). According to ISO-TS 11405, sectioned at the CEJ, human dental single roots were endodontically treated with rotatory instruments and filled with gutta-percha points and sealer. Were used at 40 J/cm2 an axial Z4 laser tip (400 m diameter) and a radial (side firing) RFT4 laser tip (415 m diameter). This density of energy was experimentally determinated observing morphological changes in SEM images due to an increase range in the energy applied to dentinal root canal surface. At the length between 32 and 49 J/cm2 most of the intracanal dentinal tubules were open. The temperature increase was within the biological safe suggesting a feasible clinical use. Each root canal was irradiated five times with helicoidal movements from apical to cervical, with 20 seconds interval. FRC Postec were immediately cemented and randomly divided in nine groups (n=10). Each root canal was cut in six discs for push out test, were the maximum failure load was obtained and the bond strength was calculated as a function of post bonded area. The bond strength for the irradiated groups was superior among all control groups. The evaluation of bond strength among root region (cervical, middle and apical) was performed and differences were observed. The self-adhesive (RelyX Unicem Aplicap) system was noted superior among all irradiated groups and all regions. Chemical changes were analyzed by FTIR due to dental root portion and dentinal tubules orientation to laser beam direction. The FTIR spectra obtained indicated changes due to tubules orientation and root canal portion irradiated such as the proportion among the compositional ratio without causing chemical changes. These compositional ratio alterations may affect the bond strength results. The irradiation with Er,Cr:YSGG laser on dentinal walls of a prosthetic post space preparation before the post cementation, as suggested in this study, may increase the bond strength between the post and root canal dentin depending upon the luting cement that is used.