Este estudo foi apoiado pelo Centro de Minnesota Dental Research de Biomateriais e Biomecânica (MDRCBB).

Nota: Três resinas compostas dentais foram estudados usando as cavidades de vidro: Z100, Z250 e LS, conforme listado na Lista de Materiais. Entre eles, LS é conhecido por ser um compósito de resina de baixo encolhimento com uma contracção volumétrica de cerca de 1,0%, muito menor do que os da Z250 e Z100 (~ 2% e -2,5%, respectivamente), 18-19. O equipamento e materiais usados ​​neste estudo são também apresentados na Lista de Materiais. 1. Modelo Preparação da Cavidade <ol><li> Corte um bastão de vidro cilíndrico de comprimento, 10 mm de diâmetro, em 10 mm de comprimento hastes curtas usando uma serra de diamante de baixa velocidade. </li><li> Corte um (MOD) cavidade-oclusal-distal mesial (Figura 1), medindo 3 mm (largura) x 2 mm (profundidade) em cada amostra utilizando uma serra de diamante de baixa velocidade adaptado. </li><li> Polir para baixo cada espécime cilíndrico para criar uma superfície plana perpendicular ao comprimento da cavidade, com as dimensões conforme mostrado na Figura 1. A superfície plana permite preciso focusing e calibração da imagem sobre a restauração. Daqui em diante, será denominado superfície da observação. </li><li> Preparar três amostras para cada um dos três materiais testados: Z100, Z250 e LS; consulte a tabela de materiais. </li></ol> 2. Preenchimento da cavidade com resina composta <ol><li> Aplicar uma fina camada de cerâmica Primer com uma escova para silanizadas todas as superfícies da cavidade de vidro. Isto permite que a ligação entre as superfícies de vidro e as resinas compostas. </li><li> Depois de cerca de 1 min, aplicar uma fina camada de adesivo. Utilize o sistema de LS Adesivo para LS compósitos e Adper Single Bond Plus composta Z100 e Z250. </li><li> Cure o adesivo com uma luz de cura e duração (10-20 seg) com base nas instruções do fabricante (tabela de materiais). </li><li> Cobrir todas as superfícies de vidro circundantes da restauração com fita preta, excepto a superfície de observação, tal como mostrado na Figura 2. O objectivo é evitar a luz de atingir o curaresina composta através do vidro transparente ao redor, o que não acontece em dentes reais. </li><li> Bulk-preencher a cavidade com resina composta e raspe todo o excesso para achatar todas as superfícies. </li></ol> 3. Pintura de Superfície <ol><li> Borrife uma fina camada de tinta branca sobre a superfície da observação, que agora inclui parte da resina composta. </li><li> Polvilhe um pouco de pó de carvão vegetal imediatamente fina preta sobre a pintura para criar manchas de alto contraste. As formas irregulares das manchas ajudará o software DIC para identificá-los e acompanhar seus movimentos. </li></ol> 4. Amostra de montagem, de cura, e Fotografar <ol><li> Fazendo referência à Figura 2, colocar uma amostra de (E) para o suporte (C) e apertá-lo com um parafuso (D). Em seguida, colocar toda a unidade, no final de um grande feixe horizontal. </li><li> Fixar uma câmera CCD e uma iluminação LED luz amarela para o mesmo feixe de tal forma que eles enfrentam o OBSERVAÇÕEn superfície. </li><li> Usando um suporte com braçadeiras ajustáveis, posicione a luz de cura de tal forma que sua ponta é de cerca de 1 mm acima da amostra. </li><li> Tire uma foto do corpo de prova para fornecer a imagem de referência antes da cura. </li><li> Cure a resina composta por 20 s. </li><li> Tirar outra foto, a 5 min após a cura. </li><li> Coloque um bloco de calibração na mesma posição como a superfície de observação e tirar uma foto. O bloco de calibração contém uma matriz de pontos circulares com um tamanho e espaçamento precisamente conhecida. </li></ol> 5. Image Analysis Software com DIC <ol><li> Importe as duas fotos tiradas para cada amostra, uma antes e outra após a cura, para o software DIC. </li><li> Calibrar as dimensões das imagens e para corrigir a distorção da imagem utilizando a imagem do bloco de calibração. . </li><li> Definir a área de interesse dentro da superfície de observação para análise. </li><li> Definir o tamanho das janelas quadradas de subconjunto como 64 x 64 pixels para oprimeira iteração e 32 x 32 pixels para a segunda iteração 20. Definir a sobreposição de 50%. </li><li> Correlacionar a imagem obtida após a cura da imagem de referência tomado antes da cura para calcular as distribuições de deslocamentos e deformações com. </li></ol>

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Os autores declaram que não têm interesses financeiros concorrentes.

O uso de cavidades de vidro com a mesma forma e dimensões para a medição da tensão de encolhimento foi para minimizar a variação nos resultados devido a diferenças no tamanho, a anatomia e as propriedades do material dos dentes humanos naturais. Além disso, o vidro de sílica fundida usada neste estudo tem um módulo de Young semelhante ao esmalte, tornando-o um material de simulador adequada para dentes naturais, na medida do comportamento mecânico está em causa 21-22. Embora em restaurações dent...

Resinas compostas são amplamente utilizados em odontologia restauradora estética por causa de seus superiores e propriedades de manipulação. No entanto, apesar de ser ligado aos tecidos dentários, a contração de polimerização de resinas compostas permanece uma preocupação clínica como o estresse de contração desenvolvida pode causar descolamento na interface dente-restauração 1 -2. Consequentemente, as bactérias podem invadir e residem nas áreas falhadas e resultar em cáries secundárias. Por outro lado, se a recuperação é também ligado ao dente, a tensão de contracção pode provocar fissuras nos tecidos dos dentes. Qualquer uma dessas falhas vai pôr em perigo a vida de serviço da restauração dentária, a qual irá ser submetido a um grande número de ciclos de carga térmica e mecânica. A medição da tensão de contração de polimerização e estresse tornou-se assim indispensável no desenvolvimento e avaliação de resinas compostas dentais 3-4 </sup&gt;. Várias técnicas ou métodos de medição foram desenvolvidos 5-11 com o objetivo principal de fornecer uma configuração simples para medir o comportamento de encolhimento de materiais compósitos de resina de forma confiável. Enquanto as medições que fornecem pode ser suficiente para comparar os comportamentos de retracção de diferentes materiais, eles não ajudar na compreensão de como e onde o stress encolhimento desenvolve em dentes restaurados reais. Especificamente, uma questão de grande interesse é a forma como as paredes da cavidade restringir o encolhimento de compósitos e leva à criação de estresse de contração em restaurações dentárias 12. Note-se que, para criar tensão de contração, parte da tensão de encolhimento do compósito de resina tem de ser convertida em tensão de tracção elástica. Por conseguinte, seria útil se este componente da estirpe na restauração pode ser medido. Recentemente, a medição da tensão-técnica óptica de campo total, digital de correlação de imagem (DIC), foi aplicado para a medição de shrinka livrege de resinas compostas, bem como o fluxo de materiais em restaurações dentárias 13-15. A ideia básica da DIC é controlar e correlacionar padrões visíveis sobre a superfície da amostra a partir de imagens sequenciais realizadas durante a sua deformação em que o deslocamento e os campos de deformação sobre a superfície pode ser determinada. Medição de campo total é uma das principais vantagens do método de DIC, que é especialmente útil em observar a deformação não uniforme e os padrões de deformação 13. Neste estudo, o DIC foi usado para descobrir os padrões de tensão em restaurações de resina composta dental, com o objetivo de compreender o desenvolvimento da tensão de contração e identificar locais potenciais para a descolagem. Esta informação não está disponível diretamente nas obras citadas acima 14-15, que só medem o deslocamento da restauração, devido à contração de polimerização. A medição foi realizada por meio de modelos que simulavam dentes com mesial-oclusal-distal (MOD) cárie dentária como uma tentativa de réplicate o estresse ou tensão em restaurações dentárias reais. Embora o uso de dentes real é anatomicamente mais representativa, a desvantagem de que são as diferenças inerentes significativas entre os dentes em anatomia, propriedades mecânicas, grau de hidratação, bem como a defeitos internos invisíveis 14 que resultam em grandes variações nos resultados. Para superar essa desvantagem, alguns estudos têm tentado padronizar as amostras de dentes, agrupando-os em termos de tamanho 16 ou bucal substituiu os dentes em conjunto com modelos de um material substituto 17. Por exemplo, modelos de alumínio que têm um módulo de Young semelhante ao esmalte (69 e 83 GPa, respectivamente) têm sido utilizados na medição da tensão de encolhimento, com o nível de tensão de encolhimento ser indicada pela deformação de cúspide 17. Neste estudo, os modelos de vidro de sílica (cavidades) foram usados ​​em vez porque o material também tem um módulo de Young semelhante (63 GPa) de esmalte humano e, como é transparenteent, qualquer descolamento ou rachaduras nas amostras pode ser facilmente observado.

<table border="0" cellpadding="0" cellspacing="0" width="790">
	<tbody>
		<tr height="42">
			<td height="42" style="height:42px;width:191px;">Dental composite Z100</td>
			<td style="width:167px;">3M ESPE</td>
			<td style="width:175px;">N362979</td>
			<td style="width:259px;">volume shrinkage ~ 2.5%, Young&#39;s modulus ~ 14 GPa</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:191px;">Dental composite Z250</td>
			<td>3M ESPE</td>
			<td style="width:175px;">N326080</td>
			<td style="width:259px;">volume shrinkage ~ 2.0%, Young&#39;s modulus ~ 11 GPa</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:191px;">Dental composite LS</td>
			<td>3M ESPE</td>
			<td style="width:175px;">N240313</td>
			<td style="width:259px;">volume shrinkage ~ 1%, Young&#39;s modulus ~ 10 GPa</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Ceramic Primer</td>
			<td>3M ESPE</td>
			<td style="width:175px;">N167818</td>
			<td style="width:259px;">Rely X</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">LS System Adhesive</td>
			<td>3M ESPE</td>
			<td style="width:175px;">N391675</td>
			<td style="width:259px;">Adhesive for compoiste LS</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Adper Single Bond Plus</td>
			<td>3M ESPE</td>
			<td style="width:175px;">501757</td>
			<td style="width:259px;">Adhesive for compoiste Z100 and Z250</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Glass rod&#160;</td>
			<td>Corning Inc.</td>
			<td>&#160;Pyrex 7740 borosilicate&#160;</td>
			<td style="width:259px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:191px;">Curing light&#160;</td>
			<td>3M ESPE</td>
			<td>Elipar S10&#160;</td>
			<td style="width:259px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:191px;">White paint&#160;</td>
			<td>Krylon Product Group</td>
			<td style="width:175px;"></td>
			<td style="width:259px;">Indoor/Outdoor, Flat white</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:191px;">Charcoal powder&#160;</td>
			<td>Sigma Aldrich, Co.</td>
			<td style="width:175px;">BCBH6518V</td>
			<td style="width:259px;">Fluka activated charcoal</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">CCD camera&#160;</td>
			<td>Point Grey Research, Inc.</td>
			<td>Point Grey Gras-20S4C-C</td>
			<td style="width:259px;"></td>
		</tr>
	</tbody>
</table>

shrinkage of dental composite in simulated cavity measured with digital image correlation

A contração de polimerização de resinas compostas dentais pode levar ao descolamento restauração ou tecidos dentários em dentes rachados compostas-restaurado. A fim de entender onde e como tensão e estresse de contração desenvolver em tais dentes restaurados, Digital Correlação de Imagem (DIC) foi usado para fornecer uma visão abrangente das distribuições de deslocamentos e deformações em restaurações do modelo que haviam sido submetidos a contração de polimerização. As amostras com cavidades do modelo foram feitas de hastes de vidro cilíndricos com diâmetro e comprimento sendo 10 mm. As dimensões da cavidade mesial oclusal-distal (MOD) preparado em cada amostra medida a 3 mm e 2 mm de largura e de profundidade, respectivamente. Após o preenchimento da cavidade com resina composta, a superfície sob observação foi pulverizado com o primeiro uma fina camada de tinta branca e fina de carvão vegetal em pó preto para criar manchas de alto contraste. Fotos de superfície que foram levados antes de curar e 5 min depois. Fifinalmente, as duas imagens foram correlacionados utilizando software DIC para calcular as distribuições de deslocamentos e deformações. O composto de resina encolhida na vertical para o fundo da cavidade, com a parte superior central da restauração tendo o maior deslocamento para baixo. Ao mesmo tempo, é diminuído horizontalmente no sentido da sua linha média vertical. O encolhimento do compósito estirado do material na proximidade do &quot;dente-restauração&quot; interface, resultando em desvios de cúspide e estirpes de elevada resistência à tracção em torno da restauração. Material próximo às paredes da cavidade ou andar tinha cepas diretos principalmente nas direções perpendiculares às interfaces. Soma das duas componentes de tensão directa mostrou uma distribuição relativamente uniforme em torno da restauração e a sua magnitude aproximadamente igualada à estirpe contracção volumétrica do material.

Três amostras foram testadas para cada material. Após cada teste, a amostra foi examinada por olhos ou, se necessário, usando um microscópio. No descolamento evidente na interface &quot;dente-restauração&quot; ou craqueamento foi encontrado. A resolução das imagens foi 1.600 x 1.180 pixels com um tamanho de pixel de 5,8 mm. Com um tamanho de janela subconjunto de 32 pixels, a resolução espacial das distribuições de deslocamento era de cerca de 186 milímetros. <p class="jove_...

Watch this Scientific Journal Video about Shrinkage of Dental Composite in Simulated Cavity Measured with Digital Image Correlation at JoVE.com

Shrinkage of Dental Composite in Simulated Cavity Measured with Digital Image Correlation

A fim de compreender o desenvolvimento espacial de estresse de contração de polimerização em restaurações de resina composta-odontológicos, Digital Correlação A imagem foi usada para fornecer-campo cheio de medição de deslocamento / deformação de cavidades de vidro modelo restaurados, correlacionando imagens da restauração tomadas antes e após a polimerização.

Encolhimento da Dental Composite no Simulado Cavity Medida com Correlação Digital de Imagem

Polymerization shrinkage of dental resin composites can lead to restoration debonding or cracked tooth tissues in composite-restored teeth. In order to ...

shrinkage-dental-composite-simulated-cavity-measured-with-digital

Research

JoVE Journal

Medicine

13.4K visualizações.  University of Minnesota.  A fim de compreender o desenvolvimento espacial de estresse de contração de polimerização em restaurações de resina composta-odontológicos, Digital Correlação A imagem foi usada para fornecer-campo cheio de medição de deslocamento / deformação de cavidades de vidro modelo restaurados, correlacionando imagens da restauração tomadas antes e após a polimerização. 

Vídeo: Shrinkage of Dental Composite in Simulated Cavity Measured with Digital Image Correlation

Stem Cell Transplantation in an in vitro Simulated Ischemia/Reperfusion Model

Stem cell transplantation protocols are finding their way into clinical practice1,2,3. Getting better results, making the protocols more robust, and finding new sources for implantable cells are the focus of recent research4,5. Investigating the effectiveness of cell therapies is not an easy task and new tools are needed to investigate the mechanisms involved in the treatment process6. We designed an experimental protocol of ischemia/reperfusion in order to allow the observation of cellular connections and even subcellular mechanisms during ischemia/reperfusion injury and after stem cell transplantation and to evaluate the efficacy of cell therapy. H9c2 cardiomyoblast cells were placed onto cell culture plates7,8. Ischemia was simulated with 150 minutes in a glucose free medium with oxygen level below 0.5%. Then, normal media and oxygen levels were reintroduced to simulate reperfusion. After oxygen glucose deprivation, the damaged cells were treated with transplantation of labeled human bone marrow derived mesenchymal stem cells by adding them to the culture. Mesenchymal stem cells are preferred in clinical trials because they are easily accessible with minimal invasive surgery, easily expandable and autologous. After 24 hours of co-cultivation, cells were stained with calcein and ethidium-homodimer to differentiate between live and dead cells. This setup allowed us to investigate the intercellular connections using confocal fluorescent microscopy and to quantify the survival rate of postischemic cells by flow cytometry. Confocal microscopy showed the interactions of the two cell populations such as cell fusion and formation of intercellular nanotubes. Flow cytometry analysis revealed 3 clusters of damaged cells which can be plotted on a graph and analyzed statistically. These populations can be investigated separately and conclusions can be drawn on these data on the effectiveness of the simulated therapeutical approach.

Stem Cell Transplantation in an in vitro Simulated Ischemia/Reperfusion Model

We demonstrate how to set up an in vitro ischemia/reperfusion model and how to evaluate the effect of stem cell therapy on postischemic cardiac cells.

Transplante de Células-tronco em um In vitro Modelo de isquemia / reperfusão Simulated

Stem cell transplantation protocols are finding their way into clinical practice1,2,3. Getting better results, making the protocols more robust, and ...

Medicina

Orthotopic Hind Limb Transplantation in the Mouse

In vivo animal model systems, and in particular mouse models, have evolved into powerful and versatile scientific tools indispensable to basic and translational research in the field of transplantation medicine. A vast array of reagents is available exclusively in this setting, including mono- and polyclonal antibodies for both diagnostic and interventional applications. In addition, a vast number of genotyped, inbred, transgenic, and knock out strains allow detailed investigation of the individual contributions of humoral and cellular components to the complex interplay of an immune response and make the mouse the gold standard for immunological research. 
Vascularized Composite Allotransplantation (VCA) delineates a novel field of transplantation using allografts to replace "like with like" in patients suffering traumatic or congenital tissue loss. This surgical methodological protocol shows the use of a non-suture cuff technique for super-microvascular anastomosis in an orthotopic mouse hind limb transplantation model. The model specifically allows for comparison between established paradigms in solid organ transplantation with a novel form of transplants consisting of various different tissue components. Uniquely, this model allows for the transplantation of a viable vascularized bone marrow compartment and niche that have the potential to exert a beneficial effect on the balance of immune acceptance and rejection. This technique provides a tool to investigate alloantigen recognition and allograft rejection and acceptance, as well as enables the pursuit of functional nerve regeneration studies to further advance this novel field of transplantation.

This novel model for orthotopic hind limb transplantation in the mouse, applying a non-suture cuff technique for super-microvascular anastomosis, provides a powerful tool for in&#160;vivo mechanistic immunological research related to vascularized composite allotransplantation (VCA).

Ortotópico Hind Limb Transplantation no mouse

In vivo animal model systems, and in particular mouse models, have evolved into powerful and versatile scientific tools indispensable to basic and ...

Electrophysiological Assessment of Murine Atria with High-Resolution Optical Mapping

Recent genome-wide association studies targeting atrial fibrillation (AF) have indicated a strong association between the genotype and electrophysiological phenotype in the atria. That encourages us to utilize a genetically-engineered mouse model to elucidate the mechanism of AF. However, it is difficult to evaluate the electrophysiological properties in murine atria due to their small size. This protocol describes the electrophysiological evaluation of atria using an optical mapping system with a high temporal and spatial resolution in Langendorff perfused murine hearts. The optical mapping system is assembled with dual high-speed complementary metal oxide semiconductor cameras and high magnification objective lenses, to detect the fluorescence of a voltage-sensitive dye and Ca2+ indicator. To focus on the assessment of murine atria, optical mapping is performed with an area of 2 mm &#215; 2 mm or 10 mm x 10 mm, with a 100 &#215; 100 resolution (20 &#181;m/pixel or 100 &#181;m/pixel) and sampling rate of up to 10 kHz (0.1 ms) at maximum. A 1-French size quadripolar electrode pacing catheter is placed into the right atrium through the superior vena cava avoiding any mechanical damage to the atrium, and pacing stimulation is delivered through the catheter. An electrophysiological study is performed with programmed stimulation including constant pacing, burst pacing, and up to triple extrastimuli pacing. Under a spontaneous or pacing rhythm, the optical mapping recorded the action potential duration, activation map, conduction velocity, and Ca2+ transient individually in the right and left atria. In addition, the programmed stimulation also determines the inducibility of atrial tachyarrhythmias. Precise activation mapping is performed to identify the propagation of the excitation in the atrium during an induced atrial tachyarrhythmia. Optical mapping with a specialized setting enables a thorough electrophysiological evaluation of the atrium in murine pathological models.

This protocol describes the electrophysiological evaluation of murine atria utilizing an optical mapping system with a high temporal and spatial resolution, including dual recordings of the membrane voltage and Ca2+ transient under programmed stimulation through a specialized electrode catheter.

Avaliação eletrofisiológica de murino átrios com mapeamento óptico de alta resolução

Recent genome-wide association studies targeting atrial fibrillation (AF) have indicated a strong association between the genotype and ...

Contractions of Human-iPSC-derived Cardiomyocyte Syncytia Measured with a Ca-sensitive Fluorescent Dye in Temperature-controlled 384-well Plates

Spontaneously contracting syncytia of cardiomyocytes derived from human-induced pluripotent stem cells (hiPSC-CM) are a useful model of human cardiac physiology and pharmacology. Various methods have been proposed to record this spontaneous activity and to evaluate drug effects, but many of these methods suffer from limited throughput and/or physiological relevance. We developed a high-throughput screening system to quantify the effects of exogenous compounds on hiPSC-CM's beating frequency, using a Ca-sensitive fluorescent dye and a temperature-controlled imaging multi-well plate reader. We describe how to prepare the cell plates and the compound plates and how to run the automated assay to achieve high sensitivity and reproducibility. We also describe how to transform and analyze the fluorescence data to provide reliable measures of drug effects on spontaneous rhythm. This assay can be used in drug discovery programs to guide chemical optimization away from, or toward, compounds affecting human cardiac function.

Spontaneously contracting syncytia of cardiomyocytes derived from human-induced pluripotent stem cells are useful models of human cardiac physiology and pharmacology. Here we present a high-throughput screening system to quantify the effects of exogenous compounds on beating frequency, using a Ca-sensitive fluorescent dye and a temperature-controlled imaging multi-well plate reader.

Contrações do citoplasma de casos humanos-iPSC-derivado medida com um corante fluorescente de Ca-sensíveis em placas de 384 poços de temperatura controlada

Spontaneously contracting syncytia of cardiomyocytes derived from human-induced pluripotent stem cells (hiPSC-CM) are a useful model of human cardiac ...

Digital Handwriting Analysis of Characters in Chinese Patients with Mild Cognitive Impairment

An increasing amount of evidence shows that cognitive deficits and movement dysfunctions are not separated. Patients with mild cognitive impairment (MCI) can manifest fine motor disorders of the upper extremities. Handwriting is a complex and unique human activity involving both motor and cognitive coordination. Researchers from western countries have discovered that patients with MCI have abnormal handwriting features. However, no relevant studies have been conducted in the Chinese population. Owing to the cross-culture phenomenon of handwriting, the aim of this study is to find new handwriting tasks to demonstrate the differences in handwriting features between elderly patients with MCI and age-matched healthy individuals.

This study proposed a digital handwriting analysis of characters in individuals with mild cognitive impairment to find more information than is revealed by traditional pencil&#8211;paper handwriting analysis.

Análise de Caligrafia Digital de Personagens em Pacientes Chineses com Prejuízo Cognitivo Leve

An increasing amount of evidence shows that cognitive deficits and movement dysfunctions are not separated. Patients with mild cognitive impairment (MCI) ...

A Standardized Approach to Extra-Oral and Intra-Oral Digital Photography

Contemporary dentistry mandates a more comprehensive and personalized analysis of each patient. Technological advances in digital photography have played vital roles in diagnostic accuracy, treatment planning, execution of therapies, and outcome evaluations, including esthetic enhancement. Digital photography also provides an excellent platform for patient education, communication, and co-management of cases with other healthcare providers. However, intra-oral photography often faces challenges such as inaccessibility of areas to be captured, different moveable vs. fixed tissues involved, contamination with saliva or blood, and differing illumination needs on various locations. Thus, a more standardized and systematic approach is proposed for intra- and extra-oral documentation via digital photography to overcome the existing technical challenges. The current work will outline the appropriate equipment specifications (camera bodies, macro lens, and flashes), positions and postures of the operator and patients, proper techniques of tissue retraction, the use of appropriate intra-oral mirrors, and the essential elements such as aperture settings (F-stop), ISO, shutter speed, and white balance. This article aims to provide all dental professionals with an approachable linear array of guidelines to produce simplified and standardized visual tools for more efficient and effective documentation.

The present protocol describes a method to capture intra- and extra-oral photographs for digital documentation in the clinical practice of dentistry. The protocol highlights all the critical components involved and the commonly utilized settings to capture dental photographs for clinical documentation.

Uma abordagem padronizada para fotografia digital extra-oral e intra-oral

Contemporary dentistry mandates a more comprehensive and personalized analysis of each patient. Technological advances in digital photography have played ...

Detection and Removal of Tooth-Colored Composite Resin Using the Fluorescence-Aided Identification Technique

The detection and removal of tooth-colored filling materials is a major challenge for every dentist. The Fluorescence-aided Identification Technique (FIT) is a noninvasive tool to facilitate the distinction of composite resin material from sound tooth substance. Compared to conventional illumination, FIT is a very accurate, reliable, and fast diagnostic method. When composite resin is illuminated with a wavelength of approximately 398 &plusmn; 5 nm, certain fluorescent components make the composite resin appear brighter than the tooth structure. Any fluorescence-inducing light source with the appropriate wavelength can be used for this method. Optimally, this technique is used without additional natural or artificial lighting. The application of FIT can be used for diagnostic purposes, for example, dental charts, and additionally for the complete and minimally invasive removal of composite resin restorations, bracket debonding, and trauma splint removal. The assessment of volumetric changes after composite removal can be provided by overlapping pre- and postoperative scans and subsequent calculation using suitable software.

The Fluorescence-aided Identification Technique is a practicable, fast, and reliable approach for the differentiation of composite resin restorations from tooth substance, and facilitates the minimally invasive and complete removal of composite resin restorations and composite bonded trauma splints.

Detecção e Remoção de Resina Composta Cor de Dente utilizando a Técnica de Identificação Auxiliada por Fluorescência

The detection and removal of tooth-colored filling materials is a major challenge for every dentist. The Fluorescence-aided Identification Technique (FIT) ...

Dynamic Navigation in Endodontics: Guided Access Cavity Preparation by Means of a Miniaturized Navigation System

In the case of teeth with pulp canal calcification (PCC) and apical pathology or pulpitis, root canal treatment can be very challenging. PCC are common sequelae of dental trauma but can also occur with stimuli such as caries, bruxism, or after placing a restoration. In order to access the root canal as minimally invasive as possible in case of a necessary root canal treatment, dynamic navigation has recently been introduced in endodontics in addition to static navigation. The use of a dynamic navigation system (DNS) requires pre-operative cone-beam computed tomography (CBCT) imaging and a digital surface scan. If necessary, reference markers must be placed on the teeth before the CBCT scan; with some systems, these can also be planned and created digitally afterward. By means of a stereo camera connected to the planning software, the drill can now be coordinated with the help of reference markers and virtual planning. As a result, the position of the drill can be displayed on the monitor in real-time during preparation in different planes. In addition, the spatial displacement, the angular deviation, and the depth position are also displayed separately. The few commercially available DNS mostly consist of relatively large camera-marker-systems. Here, the DNS contains miniaturized components: a low-weight camera (97 g) mounted on the micromotor of the electric handpiece utilizing a manufacturer-specific connecting mechanism and a small marker (10 mm x 15 mm), which can be easily attached to an individually manufactured intraoral tray. For research purposes, a post-operative CBCT scan can be matched with the pre-operative one, and the volume of tooth structure removed can be calculated by the software. This work aims to present the technique of guided access cavity preparation by means of a miniaturized navigation system from imaging to clinical implementation.

Dynamic navigation systems (DNS) provide real-time visualization and guidance to the operator during endodontic access cavities preparation. The planning of the procedure requires three-dimensional imaging utilizing cone beam computed tomography and surface scans. After the export of the planning data to the DNS, access cavities can be prepared with minimal invasion.

Navegação Dinâmica em Endodontia: Preparação de Cavidade de Acesso Guiado por Meio de um Sistema de Navegação Miniaturizado

In the case of teeth with pulp canal calcification (PCC) and apical pathology or pulpitis, root canal treatment can be very challenging. PCC are common ...

Avaliação da movimentação dentária posterior da maxila usando sobreposição digital

Measuring Maxillary Posterior Tooth Movement: A Model Assessment using Palatal and Dental Superimposition

Since the introduction of Invisalign by Align Technology, Inc. in 1999, questions and debates have persisted regarding the precision of Invisalign (clear aligner) therapy, particularly when compared to the use of traditional fixed appliances. This becomes particularly significant in cases involving anteroposterior, vertical, and transverse corrections, where precise comparisons are of paramount importance. To address these inquiries, this study introduces a meticulously devised protocol, placing a primary emphasis on digitally superimposing the movement of maxillary posterior teeth to facilitate accurate analysis. The sample included 25 patients who had completed their first series of Invisalign (clear) aligners. Four maxillary digital models (pre-treatment, post-treatment, ClinCheck-initial, and final models) were digitally superimposed using the palate rugae and dentitions as stable references. A software combination was used for model superimposition and tooth segmentation. Transformation matrices then expressed the differences between the achieved and predicted tooth positions. Thresholds for clinically relevant differences were at &plusmn;0.25 mm for linear displacement and &plusmn;2&#176; for rotation. Differences were assessed using Hotelling's T-squared tests with Bonferroni correction. The mean differences in rotation (2.036&#176; &plusmn; 4.217&#176;) and torque (-2.913&#176; &plusmn; 3.263&#176;) were significant statistically and clinically, with p-values of 0.023 and 0.0003 respectively. De-rotation of premolars and torque control for all posterior teeth were less predictable. All mean differences for the linear measurements were statistically and clinically insignificant, except that the first molars seemed slightly (0.256 mm) more intruded than their predicted position. The clear aligner system appears to meet its prediction for most translational tooth movements and mesial-distal tipping in maxillary posterior teeth for non-extraction cases with mild to moderate malocclusions.

Autor em destaque: Avaliação do movimento 3D dos dentes posteriores superiores no tratamento com alinhadores transparentes

This manuscript presents a comprehensive protocol to evaluate the three-dimensional (3D) movement of maxillary posterior teeth with clear aligners using digital model superimposition, an invaluable tool in orthodontics and dentofacial orthopedics.

Mensuração da Movimentação Dentária Posterior da Maxila: Um Modelo de Avaliação por Sobreposição Palatina e Dentária

Since the introduction of Invisalign by Align Technology, Inc. in 1999, questions and debates have persisted regarding the precision of Invisalign (clear ...