Influence of material and loading location on stress distribution of inlays.

PURPOSE: To evaluate the stress distribution of inlays fabricated with restorative materials of different elastic moduli under two functional loading conditions by using three-dimensional (3D) finite element analysis (FEA) models of a second maxillary premolar. METHODS: A 3D model of a sound maxillary left second premolar and its supporting bone was generated in a previous study and reutilized under permission of the authors for the present study. Inlay models obtained from the sound tooth were then assigned according to the type and inherent elastic modulus of the restorative material used, as follows: microhybrid composite (Filtek Z250); indirect resin composite (Paradigm); lithium disilicate reinforced glass ceramic (IPS e.max Press); and type III gold alloy. The geometric models were then exported for 3D FEA. All materials were considered isotropic, homogeneous, and linear-elastic. A static load of 100 N was applied in two conditions: axially at both cusps (axial loading) and at the mesial marginal ridge (proximal loading). Maximum principal and von Mises stresses were used to analyze the stress distribution pattern in inlays and sound premolar models. RESULTS: Under axial loading condition, either resin composite, ceramic or type III gold alloy inlays generated a similar biomechanical behavior, especially in terms of stress distribution in the remaining tooth structure and cusp deflection. However, higher tensile stresses were observed along the proximal gingival margin of the preparation under proximal loading in the Z250 and Paradigm models, as well as a greater cusp deflection. In contrast, a deflection like the sound model was observed in the ceramic and gold inlay models. CLINICAL SIGNIFICANCE: Restorative materials with higher elastic modulus, such as dental ceramics and type III gold alloys, seem to be the best choice for maxillary premolars restored with inlays in the presence of occlusal contact on the marginal ridge.

Reabilitação estética e funcional com facetas diretas após histórico de traumatismo dento-alveolar / Aesthetic and functional rehabilitation with direct veneers after dento-alveolar trauma

Introdução: Acidentes esportivos relacionados à traumatismo dento-alveolar possuem alta prevalência entre crianças e o tratamento depende da extensão da fratura, das condições periodontais e endodônticas, além da idade do paciente. Objetivo: detalhar as etapas clínicas de reabilitação estética e funcional com facetas diretas em resina composta em incisivos centrais com histórico de traumatismo dento-alveolar. Relato de Caso: Paciente do gênero feminino, 12 anos, recebeu atendimento de urgência onde foi constatado fratura de esmalte e extrusão do dente 12, fratura de esmalte e dentina e avulsão do dente 11, e fratura de esmalte e dentina e subluxação do dente 21. Foi executado reposicionamento dos dentes 12 e 21, reimplante e endodontia do elemento 11 e restaurações provisórias nos três elementos dentários traumatizados. Após a remoção da contenção semi-rígida e das restaurações provisórias, faceta direta em resina composta nano-híbrida foi confeccionada nos incisivos centrais superiores e classe IV no incisivo lateral direito. Matriz de silicone foi utilizada para auxiliar na reconstrução da face palatina. Para melhor biomimetismo ótico, optou por realizar a técnica estratificada, com resina de dentina opaca (OA2) e resina de esmalte (A2) na última camada. Resultado: recuperou- -se função e estética esperados tanto pelo paciente quanto pela equipe executora. Conclusão: a utilização de resina composta para restauração pós-traumatismo dento-alveolar permitem o sucesso estético e funcional do tratamento reabilitador.

Sports accidents related to dento-alveolar trauma are highly prevalent among children and its treatment depends on the fracture extension, periodontal and endodontic conditions, beyond the age of the patient. The purpose of this case report is to detail the clinical stages of aesthetic and functional rehabilitation with direct composite resin veneers in central incisors with a history of dento- -alveolar trauma. Female patient, 12 years old, received urgency assistance, when enamel fracture and extrusin was observed on tooth 12, enamel and dentin fracture and avulsion on tooth 11, and enamel and dentin fracture and subluxation on tooth 21. The repositioning of the teeth 12 and 21 was performed, and the reimplant and endodontics treatment on tooth 11; beyond provisional resotation. After removal of the semi-rigid containment and temporary restoration, direct veneers confecctioned with nano-hybrid composite resin was made in upper central incisors, and a class IV on the right lateral incisor. Silicone matrix was used to aid the reconstrutction of the palatal face. In order to best optical biomimicry, the stratification technique was performed, with opaque dentin resin (OA2) and enamel resin (A2) in the superficial layer. As a result, the function and aesthetic were recoverd as expected both by patient and dentists. It is concluded that the use of composite resin provides aesthetic and functional rehabilitation treatment succes associated with dento-alveolar trauma.

Nova tecnologia aplicada à odontologia minimamente invasiva: relato de caso de remoção de bráquetes ortodônticos / New technology applied to minimally invasive dentistry: a case report of orthodontic brackets removes

O conceito de odontologia minimamente invasiva associado à adesão apresenta uma mudança de filosofia na prática clínica moderna. Os antigos paradigmas de extensão da região a ser restaurada para proteção do remanescente ou aumento da resistência do material restaurador fazem cada vez menos parte da rotina clínica e conceitos de conservação máxima de estrutura dentária tornam-se mais utilizados. Contudo, diante do desenvolvimento de materiais restauradores com propriedades ópticas cada vez mais semelhantes as das estruturas dentárias, definir o limite entre materiais restauradores e estrutura dental tem se apresentando como um desafio. Objetivo: O objetivo deste trabalho é demonstrar a aplicação de um conceito atual baseado na utilização de alta rotação com sistema de iluminação que evidencia o material restaurador diferenciando da estrutura dental para a remoção seletiva de compósitos resinosos utilizados para cimentar bráquetes ortodônticos. Paciente apresentou-se com aparelho ortodôntico fixo em fase final de tratamento, sendo necessária a remoção deste. Após a retirada dos bráquetes ortodônticos, o remanescente de compósito resinoso foi removido com ponta diamantada de granulação fina e extrafina (FG2135 F e FF, KG Sorensen) acoplada em alta rotação que emite luz em comprimento de onda capaz de evidenciar o material restaurador em contraste com a estrutura dentária (Cobra LED Ultra-Vision, Gnatus). Assim, foi possível evidenciar interface entre dente e cimento ortodôntico devido à diferença na fluorescência, resultando assim em maior sensibilidade da técnica e preservação de tecido dentário hígido. Conclusão: Conclui-se que a utilização de alta-rotação capaz de estimular a fluorescência do material restaurador é um método eficaz para remoção de remanescente de compósitos resinosos, sendo uma técnica mais conservadora e menos invasiva.

The concept of minimally invasive dentistry associated to adhesion shows a change in the philosophy of modern clinical practice. The old paradigms of the region extension to be restored to remaining protection or increased resistance of the restorative material are less part of the clinical routine; and maximum conservation of tooth structure concepts become more used. However, in front of the development of restorative materials with optical properties more like to the dental structures, define the limit between restorative materials and tooth structure has been presented as a challenge. The objective of this article is to demonstrate the application of a current concept based on the use of light for the selective removal of resins derived from orthodontic procedures. Patient has attended at the end of treatment, and the removal the orthodontic dispositive is necessary. After the removal of brackets, the composite resin remaining was removed with a fine grain and extra-fine diamond burn (FG 2135 F and FF, KG Sorensen) coupled at high speed with light emission in the specific frequency for highlight the restoration material (LED Cobra Ultra-Vision, Gnatus). The light output of this frequency showed the interface between the tooth and the orthodontic cement due to the difference in fluorescence, thus resulting in higher sensitivity of the technique and preservation of healthy dental tissue. It is concluded that the use of high-speed with light emission is an effective method for removal of resin composite remaining and it is a conservative and less invasive procedure.

Crown fracture: Failure load, stress distribution, and fractographic analysis.

STATEMENT OF PROBLEM: The outcomes from load-to-failure tests may not be applicable to clinical situations. PURPOSE: The purpose of this study was to critically evaluate the efficacy of load-to-failure tests in the investigation of the fracture load and pattern of metal-free crowns. MATERIAL AND METHODS: Four groups were formed from 128 bovine roots restored with metal posts, resin cores, and feldspathic, leucite, or lithium disilicate ceramic systems or polymer crowns. Each group was divided into 4 (n=8) according to the cement: zinc phosphate, self-adhesive resin, autopolymerizing resin, and glass ionomer. Mean fracture loads from compressive tests were submitted to ANOVA and Tukey HSD test. Finite element and fractographic analyses were performed and associated with the fracture load and pattern. RESULTS: Significantly higher fracture load values were obtained for the lithium disilicate ceramic, but finite element and fractographic analyses showed that the cement effect could not be determined. The finite element analysis showed the cement likely affected the fracture pattern, confirmed that stresses in the cements were little affected by the crown materials, and found that the stressed conditions were lowest in the lithium disilicate compared with other crowns for all cement combinations. The stressed conditions in the crowns depended more on the adhesive properties than on the elastic modulus of the cement materials. The level of the stressed condition in the crowns at the occlusal surface was about the same or higher than along their cement interface, consistent with the fractography, which indicated fractures starting at the load point. Higher stress levels in the crowns corresponded with a lower number of catastrophic fractures, and higher stresses in the cements seemed to reduce the number of catastrophic fracture patterns. The highest stressed conditions occurred along the occlusal surface for crown materials with a low elastic modulus or in combination with adhesive cements. CONCLUSIONS: The method used was not appropriate either for investigating the crowns' fracture load and pattern or for stating the role of the cements within the crown-cement-tooth interaction.

Avaliação da qualidade do atendimento oferecido na Clínica Integrada da Universidade Federal de Uberlândia / Evaluation of the quality of care offered in the Integrated Clinic of the Federal University of Uberlândia

Objetivo: Verificar a qualidade da atenção à saúde bucal oferecida na disciplina de clínica integrada do curso de Odontologia, por meio da avaliação da satisfação dos pacientes. Metodologia: Este trabalho foi realizado nas Clínicas Integradas do curso de Odontologia da Universidade Federal de Uberlândia, na sala de espera do 5º ao 8º período. O trabalho foi caracterizado como um estudo qualiquantitativo. Preliminarmente para ajustar o instrumento de coleta foi realizado um piloto junto a 30 pacientes. Nesta avaliação, observarmos as sugestões à sua elaboração e conhecimento dos termos utilizados. Foi utilizada uma amostra aleatóriade 138 pacientes (n=138). Para cálculo da amostra foi utilizado um nível de confiança de 95% e erro amostral de 0,05. A técnica de amostragem utilizada foi amostra aleatória simples. Trata-se de um estudo transversal cujo desfecho é avaliar a satisfação do paciente. Resultados: Em sua maioria, constituído por pacientes do gênero feminino (92,43%) e tinham entre 35 e 49 anos (36,23%). O motivo principal por ter procurado o atendimento foi motivo financeiro (51,44%). Foram analisados os seguintes fatores: acesso ao tratamento/prontuário, portaria/recepção, organização do hospital, secretária da clínica, atendimento prestado pelo aluno e professor. Em todas analises foram encontrados resultados representados em sua maioria por satisfeitos e muito satisfeitos. Conclusão: Notou-se a importância da avaliação dos serviços prestadosem Clínicas Integradas nas Faculdades de Odontologia, pois estes servem de auxílio para melhorar o atendimento e o ensino nestas instituições. As insatisfações serão encaminhadas para os responsáveis, para que possam ser melhoradas e sanadas.

Objective: To evaluate the quality of dental care offered in the discipline of integrated clinical course of Dentistry, through the evaluation of patient satisfaction. Methodology: This study was conducted on the Integrated Clinical Course of Dentistry, Federal University of Uberlandia, in the waiting room of the 5th to 8th period. The work was characterized as a qualitativeand quantitative study. Preliminarily to adjust the instrument to collect a pilot was conducted with 30 patients. In this evaluation, we observe the suggestions for their preparation and knowledge of the terms used. A random sample of 138 patients (n = 138) was used. To calculate sample a confidence level of 95% and a sampling error of 0.05 was used. The sampling technique used was simple random sample. It is a cross-sectionalstudy whose outcome is to assess patient satisfaction. Results: The majority comprised of female patients (92.43%) and 35 and 49 years (36.23%). The main reason for seeking care was financial reason (51.44%). Access to treatment / medical records, concierge / reception, organization of hospital, clinic secretary, care provided by the student and teacher: The following factors were analyzed. In all analysis results represented mostly by satisfied and very satisfied were found. Conclusion: It was noted the importance of evaluating the services in Integrated Clinical Faculties of Dentistry because they serve to aid to improve care and education in these institutions. The grievanceswill be forwarded to those responsible, so they can be improvedand corrected.

Análise das dimensões padrões das macrogeometrias de pontas diamantadas de diferentes fabricantes e modelos / Analysis of the macrogeometry pattern dimensions of diamond burs of different manufacturers and models

Pontas diamantadas são instrumentos rotatórios abrasivos de uso rotineiro na prática clínica odontológica, com macrogeometria constituída de haste metálica, ponta ativa e eixo Intermediá- rio. Objetivo: avaliar as dimensões padrões dos componentes que constituem a macrogeometria das pontas diamantadas. Material e Método: a fim de padronização, considerou-se como ponta ativa a região do instrumental que possui granulação; como eixo Intermediário a região compreendida entre a primeira depressão presente na base até o início da ponta ativa; e como haste metálica toda região localizada entre a base da ponta diamantada até a primeira depressão. Realizou os testes com seis marcas comerciais: KG Sorensen, Option, Vortex, Microdont, Zeep e Fava. Foram selecionadas 120 pontas diamantadas tronco-cônicas, modelos 2200 (n=10) e 2135 (n=10). O diâmetro e comprimento foram analisados em sete regiões correspondentes à macrogeometria. O diâmetro do orifício de encaixe de pontas diamantadas em turbinas de alta rotação de cinco marcas (Gnatus, Kavo, Calu, Dx e Dabi) também foi mensurado. Para realizar as medidas, paquímetro digital (Mitutoyo, modelo número 6, C-B) foi utilizado por um único operador calibrado. Resultado: as dimensões de ambos os modelos de pontas diamantadas apresentaram variação, quando comparado os fabricantes, seja no comprimento total da haste metálica, eixo intermediário ou ponta ativa. A marca comercial KG Sorensen apresentou baixa alteração na dimensão entre seus instrumentos. Conclusão: a não padronização das pontas diamantadas pode prejudicar a confecção de preparos e também o aprendizado de estudantes de odontologia.

Diamond burs are abrasive rotary instrumental routinely used in clinical dentistry practice with macro geometry consists of metal stem, the active tip and intermediate shaft. Objective: evaluate the standardized dimensions of the components that constitute the macro geometry of the diamond bur. Methods: in order to standardize, it was considered as active tip the area of the diamond bur that has granulation; as intermediate the region between the first depression at the base until the beginning of the active tip; and as stem all region located between the base of the diamond tip to the first depression. The test was performed with six brand: KG Sorensen, Option, Microdont, FAVA, Zeep, Vortex. 120 trunk-conical diamond burs, models 2200 (n = 10) and 2135 (n = 10) were selected. The diameter and length were evaluated in seven regions corresponding to macro geometry. The diameter of the diamond bur orifice fitting on the high speed turbines of five brands (Gnatus, Kavo, Calu, Dx and Dabi) were also measured. A digital caliper (Mitutoyo, modelo número 6, C-B) was used for measurements by a single calibrated operator. Results: the dimensions of both models showed variation compared trademarks, either in the total length of the metal stem, active tip or intermediary. KG Sorensen trademark presented low alterations in size between their instruments. Conclusion: the non-standardized of diamond burs can hamper the confection of preparations and also the learning of dental students.

Influência do modelo e marca de ponta diamantada na resistência flexural / Influence of model and brand of diamond bur in flexural strength

Introdução: As pontas diamantadas são instrumentos rotatórios abrasivos utilizados principalmente na odontologia restauradora para realização de preparos dentários e acabamentos de restaurações. Estes instrumentos são formados por uma haste metálica, eixo intermediário e ponta ativa. Objetivo: Mensurar a resistência flexural da haste e intermediário de pontas diamantadas de seis marcas comerciais diferentes disponíveis no mercado brasileiro. Materiais e Métodos: utilizou- se 60 pontas diamantadas, sendo 30 pontas 2200 (n=5) e 30 pontas 2130 (n=5), das marcas KG Sorensen, Option, Microdont, FAVA, Zeep, Vortex. Os instrumentos rotatórios foram posicionados em dispositivo que permitiu que suas extremidades fossem apoiadas sobre bases metálicas; submetidas à Máquina Universal de Ensaio (EMIC), para mensurara força máxima aplicada em um deslocamento de 3 mm. Para o padrão de falha, verificou-se se as pontas sofreram dobras ou fraturas totais. Resultado: os instrumentos rotatórios da marca KG Sorensen destacaram-se em todos os testes, apresentando elevados valores de resistência flexural tanto para haste quanto para intermediário; não apresentando nenhuma falha do tipo fratura total. A marca Option apresentou o maior índice de instrumentos com falha do tipo fratura total.Conclusão: não existe padronização da resistência flexural entre as marcas comercias, sendo que a utilização de instrumentos com baixa resistência pode ocasionar maiores taxas de falha, danificando o equipamento ou causar injurias aos tecidos do paciente.

Introduction: The diamond burs are rotary abrasives instruments primarily used in restorative dentistry to perform dental preparations and finishing restorations. These instruments consist of shank, intermediate shaft and head. Objective: To measure the flexural strength of the shank and intermediate shaft diamond burs of six different commercial brands available in the Brazilian market. Methods: 60 diamond burs, 30 burs 2200(n = 5) and 30 burs 2135 (n = 5), of brands KG Sorensen, Option, Microdont, FAVA, Zeep, Vortex were used. The rotary instruments were placed in the device that allowed its ends were supportedon metal bases; submitted to Universal Testing Machine (EMIC), to measure the maximum force applied a displacement of 3mm. For the standard fault, it was found that the burs suffered bends or total fractures. Results: It was observed that the rotary instruments KG Sorensen, stood out all tests, showing high values of flexural strength for shank and intermediate shaft; showing no fault of type fracture total. Option had the highestrate of failure type instruments with total fracture. Conclusion: There is no standardization between the flexural trademarks, and the use of instruments with low resistance may cause higher rates of failure, damaging the equipment or cause injuries to the tissues of the patient.

Does bonding to dentin reduce microleakage of composite restorations?

This study evaluated the effect of adhesive application only to enamel on the marginal microleakage of composite resin restorations performed with different adhesive systems. Standardized cylinder-shaped cavities were prepared on the buccal surface of eighty bovine incisors. Two etch-and-rinse (Adper Scotchbond Multi-purpose [3M ESPE, St. Paul, MN USA] and Adper Single Bond 2 [3M ESPE]) and two self-etching (Clearfil SE Bond [Kuraray, Osaka, Japan] and Adper Prompt [3M ESPE]) adhesive systems were evaluated. The adhesives were applied only to enamel or to both dentin and enamel. After adhesive light-activation, the cavities were restored with composite resin. The samples were coated with two layers of nail polish, except an area of 1-mm wide around of the restoration, and immersed in a methylene blue solution. Afterwards, the specimens were ground in order to obtain powder which was immersed in absolute alcohol. The solutions were centrifuged and the supernatant was analyzed using an absorbance spectrophotometer. Linear regression was used to estimate the dye concentration. Data were analyzed using ANOVA and Tukey's tests (alpha = 0.05). The etch-and-rinse adhesives showed lower microleakage means compared to those of the self-etching adhesives. Adper Prompt presented higher microleakage means. There was no difference between the modes of application of the adhesive on the cavity for all adhesive systems, except for Clearfil SE Bond. This showed lower microleakage when applied to the whole cavity. Bonding to dentin may not reduce microleakage of composite restorations.

Reabilitação estética do sorriso com facetas cerâmicas reforçadas por dissilicato de lítio / Aesthetic rehabilitation with ceramic veneers reinforced by lithium disilicate

A constante busca por um sorriso harmônico e estético eleva o nível de exigência e de expectativa dos pacientes. As facetas laminadas destacam-se como opção de tratamento para a reabilitação estética na prática clínica por proporcionarem procedimentos mais conservadores e com mimetismo das estruturas dentais. O desenvolvimento de novos sistemas cerâmicos reforçados por dissilicato de Lítio e dos cimentos resinosos auto-adesivos, favoreceu o aumento da longevidade e a performance clínica das restaurações estéticas indiretas. Este trabalho tem por objetivo apresentar relato de caso clínico de reabilitação estética do sorriso, descrevendo protocolo de confecção dos preparos convencionais, moldagem e cimentação de facetas cerâmicas reforçadas com dissilicato de Lítio, visando sucesso no tratamento e satisfação do paciente.

The constant search for a harmonious and aesthetic smileraises the level of expectation by patients. Ceramic veneers are a treatment option for aesthetic rehabilitation in clinical practice by providing more conservative procedures and with excellent optical properties. The development of new ceramic systems reinforced with lithium disilicate and self-adhesive resin cements, favored the increase in longevity and clinical performance of esthetic indirect restorations. The aim of this paper is to present a clinical case, discribing the protocol for conducting conventional preparations, molding and cementation of ceramic veneer reinforced by lithium disilicate, with success in treatment and patient satisfaction.

Uso de coroa em cerâmica pura associada a pino de fibra de vidro na reabilitação estética do sorriso: relato de caso / All ceramic crown associated to fiberglass post: a clinical case report

Restauração de dentes tratados endodonticamente constituidesafio permanente na odontologia, uma vez que aspectos biomecânicos,estéticos e complexidade de execução técnica podemresultar em insucesso com consequente perda do elemento dentário.Geralmente dentes tratados endodonticamente se encontramenfraquecidos devido à perda de estrutura dentária o queresulta em redução de resistência mecânica da dentina. Estesfatores resultando em maiores riscos de falhas biomecânicasquando comparados aos dentes com vitalidade pulpar. Este trabalhotem por objetivo apresentar procedimentos clínicos reabilitadorespara devolução de harmonia estética com ênfase emprocedimentos realizados em incisivo central superior com extensaperda de estrutura coronária e restauração em resina compostainsatisfatória. Foi empregada a associação de pino de fibrade vidro (Exacto, Ângelus) e resina composta para reconstruçãointerna seguido de coroa em cerâmica pura (In Ceram Alumina,Vita). São destacados os passos clínicos e breve revisão de aspectosbiomecânicos e estéticos desta alternativa reabilitadora.

Restoration of endodontically treated teeth is a challenge inoperative dentistry, since the biomechanical, aesthetic and complexityof the technique can result in failure with subsequenttooth loss. Generally endodontically treated teeth are weakeneddue to loss of tooth structure and reduce the mechanicalstrength of dentin. These factors result in a higher risk of biomechanicalfailure when compared to teeth with pulp vitality.This paper aims to present clinical rehabilitation procedures torecover the smile harmony with an emphasis on aesthetic proceduresperformed in the maxillary central incisor with extensiveloss of coronal tooth tissue and unsatisfactory compositeresin restoration. It was employed the combination of fiberglasspost (Exacto, Angelus) and coronal reconstruction with compositeresin followed by all ceramic alumina crown (In CeramAlumina, Vita). Highlights the clinical steps and brief review ofbiomechanical and aesthetic rehabilitation of this alternative aredescribed.

Finite element analysis and bond strength of a glass post to intraradicular dentin: comparison between microtensile and push-out tests.

OBJECTIVE: This study tested the hypothesis that the stress distribution and bond strength of glass posts to intraradicular dentin is influenced by the mechanical testing methodology. METHODS: Thirty single rooted endodontically treated teeth were prepared for luting of tapered fiber-glass posts (Reforpost, Angelus, Londrina, PR, Brazil) with a conventional adhesive system and resin luting cement (Adper Scotchbond Multi-purpose, Rely X ARC, 3M ESPE, St. Paul, MN, USA). The teeth were randomly divided (n=10 per group) into micro-push-out (Mpo), hourglass- (Mh) and rectangular stick-shaped (Ms) microtensile testing groups before sectioning each root into five 1-mm-thick specimens. During specimen preparation for microTBS testing 46/50 stick and 4/50 hourglass specimens prematurely failed; therefore, the Ms group could not be included in the mechanical testing. The remaining specimens were tested at 0.5 mm/min until bond failure. Stress distribution within each specimen type for the three mechanical test methods was analyzed by finite element analysis (FEA). Qualitative analyses were carried out through Von Mises, XY and Sy criterion. RESULTS: Mpo and Mh had a mean microTBS of 11.89+/-6.55 and 14.98+/-12.72 MPa, respectively, which was not significantly different (p=0.1311). The push-out test demonstrated a more homogenous stress distribution by FEA and less variability in mechanical testing. SIGNIFICANCE: Therefore, the recommended testing method for determining the bond strength of glass posts to intraradicular dentin is by Mpo.