Questo studio è stato sostenuto dal Minnesota Dental Centro di Ricerca per Biomateriali e Biomeccanica (MDRCBB).

Nota: Tre resine composite dentali sono state studiate utilizzando le cavità di vetro: Z100, Z250 e LS, elencati nella Lista dei materiali. Tra questi, LS è noto per essere un composito di resina a basso restringimento con una contrazione volumetrica di circa 1,0%, molto inferiori a quelli di Z250 e Z100 (~ 2% e ~ 2,5%, rispettivamente) 18-19. Le attrezzature e altri materiali utilizzati in questo studio sono anche indicati in Materials List. 1. Modello Preparazione della cavità <ol><li> Tagliare una bacchetta di vetro cilindrico lungo 10 mm di diametro, in 10 mm barre corte lunghe utilizzando un disco diamantato a bassa velocità. </li><li> Tagliare un (MOD) cavità occlusale-distale mesiale (Figura 1) da 3 mm (larghezza) x 2 mm (profondità) in ciascun campione utilizzando un disco diamantato a bassa velocità adeguata. </li><li> Lucidare giù ogni campione cilindriche per creare una superficie piana perpendicolare alla lunghezza della cavità, con dimensioni come mostrato in Figura 1. La superficie piatta consente preciso foCUtilizzando e calibrazione delle immagini sul restauro. D&#39;ora in poi, si chiamerà la superficie di osservazione. </li><li> Preparare tre campioni per ciascuno dei tre materiali testati: Z100, Z250 e LS; vedi tabella materiali. </li></ol> 2. Cavità di riempimento con resina composita <ol><li> Applicare un sottile strato di ceramica Primer con una spazzola a silanizzata tutte le superfici della cavità di vetro. Questo permette l&#39;incollaggio tra le superfici di vetro e le resine composite. </li><li> Dopo circa 1 min, applicare uno strato sottile di adesivo. Usare il sistema LS LS adesivo per compositi e Adper Single Bond Plus per composito Z100 e Z250. </li><li> Curare l&#39;adesivo con un leggero indurimento e la durata (10-20 sec) in base alle istruzioni del produttore (tabella Materials). </li><li> Coprire tutte le superfici vetrate circondano il restauro con nastro nero tranne la superficie di osservazione, come mostrato nella Figura 2. Lo scopo è quello di evitare la fotopolimerizzazione raggiungere laresina composita attraverso il vetro trasparente circostante, cosa che non accade in denti veri. </li><li> Bulk-riempire la cavità con resina composita e raschiare la parte in eccesso per appiattire tutte le superfici. </li></ol> 3. Painting Surface <ol><li> Spruzzare un sottile strato di vernice bianca sulla superficie di osservazione, che ora comprende parte della resina composita. </li><li> Cospargere subito qualche nero polvere fine di carbone sulla vernice per creare macchioline ad alto contrasto. Le forme irregolari delle macchioline aiuterà il software DIC di identificarli e di seguire i loro movimenti. </li></ol> 4. Montaggio Campione, polimerizzazione, e fotografia <ol><li> Facendo riferimento alla Figura 2, posizionare un campione (E) nel supporto (C) e serrarlo con una vite (D). Quindi, posizionare il tutto al fine di una grande trave orizzontale. </li><li> Fissare una camera CCD e una luce LED giallo illuminazione sullo stesso fascio tale che si trovano ad affrontare la observatiosuperficie n. </li><li> Utilizzo di un supporto con morsetti regolabili, posizionare la luce polimerizzazione tale che la sua punta è di circa 1 mm sopra il campione. </li><li> Scatta una foto del campione per fornire l&#39;immagine di riferimento prima di curare. </li><li> Curare la resina composita per 20 sec. </li><li> Scattare un&#39;altra foto a 5 min dopo l&#39;indurimento. </li><li> Posizionare un blocco di calibrazione nella stessa posizione come la superficie di osservazione e scattare una foto. Il blocco di calibrazione contiene una serie di punti circolari con le dimensioni e la spaziatura nota con precisione. </li></ol> 5. Image Analysis con CID Software <ol><li> Importare le due foto scattate per ogni campione, uno prima e uno dopo l&#39;indurimento, nel software DIC. </li><li> Calibrare le dimensioni delle immagini e correggere la distorsione dell&#39;immagine utilizzando l&#39;immagine del blocco di calibrazione. . </li><li> Definire l&#39;area di interesse all&#39;interno della superficie di osservazione per l&#39;analisi. </li><li> Definire la dimensione delle finestre sottoinsieme quadrati come 64 x 64 pixel per laprima iterazione e 32 x 32 pixel per la seconda iterazione 20. Definire la sovrapposizione al 50%. </li><li> Correlare l&#39;immagine scattata dopo il trattamento l&#39;immagine di riferimento preso prima di curare per calcolare le distribuzioni di spostamento e deformazione con. </li></ol>

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Gli autori dichiarano di non avere interessi finanziari in competizione.

L&#39;uso di cavità di vetro con la stessa forma e dimensioni per la misurazione della deformazione restringimento era di ridurre le variazioni dei risultati a causa di differenze di dimensioni, anatomia e proprietà del materiale di denti umani naturali. Inoltre, il vetro di silice fusa utilizzato in questo studio ha un modulo di Young simile allo smalto, rendendolo un materiale simulante adatto per denti naturali per quanto riguarda il comportamento meccanico 21-22. Sebbene in restauri dentali reali, la re...

Resine composite sono ampiamente utilizzati in odontoiatria restaurativa a causa della loro estetica superiore e maneggevolezza. Tuttavia, nonostante sia legato ai tessuti dentali, la contrazione da polimerizzazione di compositi di resina rimane un problema clinico come stress da contrazione sviluppato può causare delaminazione all&#39;interfaccia dente-restauro 1 -2. Di conseguenza, i batteri possono invadere e risiedere in zone fallito e provocare carie secondarie. D&#39;altra parte, se il restauro è ben legata al dente, lo stress restringimento può provocare screpolature nei tessuti dentali. Uno di questi fallimenti comprometterà la durata della restaurazione dentale, che sarà sottoposto ad un elevato numero di cicli di carico termico e meccanico. Misurazione di tensione da polimerizzazione e lo stress è diventato così indispensabile per lo sviluppo e la valutazione delle resine composite dentali 3-4 </sup&gt;. Varie tecniche o metodi di misurazione sono stati sviluppati 5-11 con lo scopo principale di fornire una configurazione semplice per misurare il comportamento di ritiro dei materiali compositi di resina affidabile. Mentre le misurazioni che forniscono possono essere sufficienti per confrontare i comportamenti di ritiro di materiali diversi, non aiutano nella comprensione di come e dove stress da contrazione sviluppa in denti restaurati reali. In particolare, una questione di grande interesse è come le pareti della cavità limitano la contrazione dei compositi e porta alla creazione di stress da contrazione nei restauri dentali 12. Si noti che, per creare stress da contrazione, parte del ceppo contrazione del composito resina deve essere convertito in deformazione elastica a trazione. Sarebbe pertanto utile se questa componente del ceppo nel restauro può essere misurata. Recentemente, l&#39;intero campo di deformazione misurazione tecnica ottica, Digital Image Correlation (DIC), è stato applicato alla misurazione di shrinka liberoge di materiali compositi di resina, così come il flusso dei materiali in protesi dentali 13-15. L&#39;idea di base di DIC è seguire e correlare modelli visibili sulla superficie del campione da immagini sequenziali prelevati durante la sua deformazione per cui lo spostamento e campi di deformazione su quella superficie possono essere determinati. Misura tutto campo è uno dei principali vantaggi del metodo DIC, che è particolarmente utile in osservazione deformazione non uniforme e modelli di deformazione 13. In questo studio, DIC stato usato per scoprire i modelli di deformazione in restauri resina composita dentale, allo scopo di comprendere lo sviluppo di stress da contrazione e identificare siti potenziali per delaminazione. Questa informazione non è direttamente disponibile nelle opere citate sopra 14-15, che misura solo lo spostamento del restauro causa di polimerizzazione. La misurazione è stata condotta utilizzando modelli che hanno simulato denti con mesio-occlusale-distale (MOD) cavità dente come un tentativo di replicaTe lo stress o tensione nella protesi reali. Sebbene l&#39;uso di denti reale è più anatomicamente rappresentante, lo svantaggio di questo è le significative differenze intrinseche tra i denti di anatomia, proprietà meccaniche, grado di idratazione e difetti interni invisibili 14 che portano a grandi variazioni nei risultati. Per superare tale inconveniente, alcuni studi hanno cercato di standardizzare campioni denti, raggruppandoli in termini di dimensioni buccale 16 o sostituito i denti tutto con modelli di un materiale surrogato 17. Ad esempio, i modelli di alluminio aventi un modulo di Young simile allo smalto (69 e 83 GPa, rispettivamente) sono stati impiegati nella misurazione stress da contrazione, con il livello di stress da contrazione è indicata dalla cuspide deflessione 17. In questo studio, modelli di vetro di silice (cavità) sono stati utilizzati, invece, perché il materiale ha un modulo di Young simile (63 GPa) di smalto umano e, come è trasparenteent, ogni delaminazione o incrinatura dei campioni possono essere facilmente osservati.

<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

Polimerizzazione delle resine composite dentali può portare alla delaminazione ripristino o tessuti dente rotto nei denti compositi restaurato. Per capire dove e come tensione e stress da contrazione sviluppare in tali denti restaurati, Digital Image Correlation (DIC) è stato utilizzato per fornire una visione completa delle distribuzioni di spostamento e deformazione all&#39;interno restauri del modello che avevano subito polimerizzazione. I campioni con modello cavità erano fatte di canne di vetro cilindriche sia con diametro e la lunghezza è di 10 mm. Le dimensioni della cavità mesio-occlusale-distale (MOD) preparato in ciascun campione misurato 3 mm e 2 mm di larghezza e profondità rispettivamente. Dopo aver riempito la cavità con resina composita, la superficie sotto osservazione è stato spruzzato con un primo strato sottile di vernice bianca e allora bene carbone polvere nera per creare macchiettature alto contrasto. Foto di quella superficie sono state poi prese prima cura e 5 minuti dopo. FiNally, le due immagini sono stati correlati utilizzando il software DIC per calcolare le distribuzioni di spostamento e deformazione. La resina composita ridotta orizzontalmente verso il fondo della cavità, con la parte centrale superiore del restauro avente il più grande spostamento verso il basso. Allo stesso tempo, si restringe orizzontalmente verso la linea mediana verticale. Contrazione del composito allungato il materiale nelle vicinanze dell&#39;interfaccia &quot;dente-restauro&quot;, con conseguente deviazioni cuspidali e ceppi ad alta resistenza di tutto il restauro. Materiale vicino alle pareti della cavità o piano aveva ceppi diretti soprattutto nelle direzioni perpendicolari alle interfacce. Sommatoria dei due componenti scalo deformazione mostrato una distribuzione relativamente uniforme intorno il restauro e la sua grandezza pari a circa al ceppo ritiro volumetrico del materiale.

Tre campioni sono stati saggiati per ciascun materiale. Dopo ogni test, il campione è stato esaminato da occhi o, se necessario, utilizzando un microscopio. È stata trovata alcuna apparente delaminazione all&#39;interfaccia &quot;dente-restauro&quot; o di cracking. La risoluzione delle immagini era 1.600 x 1.180 pixel con una dimensione di pixel di 5,8 mm. Con una dimensione di finestra sottoinsieme di 32 pixel, la risoluzione spaziale delle distribuzioni di spostamento era circa 186 mm. <...

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

Per capire lo sviluppo territoriale dello stress da polimerizzazione nei restauri resina composita dentale, Digital Image Correlation è stato utilizzato per fornire a tutto campo la misura dello spostamento / deformazione del modello cavità vetro restaurate correlando le immagini del restauro prese prima e dopo la polimerizzazione.

Restringimento della Dental composito in simulata cavità misurato con Digital Image Correlation

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

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Research

JoVE Journal

Medicine

13.3K Views.  University of Minnesota.  Per capire lo sviluppo territoriale dello stress da polimerizzazione nei restauri resina composita dentale, Digital Image Correlation è stato utilizzato per fornire a tutto campo la misura dello spostamento / deformazione del modello cavità vetro restaurate correlando le immagini del restauro prese prima e dopo la polimerizzazione. 

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

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).

Ortotopico degli arti posteriori del trapianto di mouse

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

Ricerca

Medicina

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.

Valutazione elettrofisiologica di Atria murino con Mapping ottico ad alta risoluzione

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.

Contrazioni di umano-iPSC-derivato del Cardiomyocyte sincizi misurata con un colorante fluorescente Ca sensibile a temperatura controllata piastre da 384 pozzetti

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.

Analisi digitale della grafia dei caratteri nei pazienti cinesi con lieve deficit cognitivo

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

Evaluation of Capillary and Other Vessel Contribution to Macular Perfusion Density Measured with Optical Coherence Tomography Angiography

Parafoveal circulation of the superficial retinal capillary plexus is usually measured with vessel density, which determines the length of capillaries with circulation, and perfusion density, which calculates the percentage of the evaluated area that has circulation. Perfusion density also considers the circulation of vessels larger than capillaries, although the contribution of these vessels to the first is not usually evaluated. As both measurements are automatically generated by optical coherence tomography angiography devices, this paper proposes a method for estimating the contribution of vessels larger than capillaries by using a coefficient of determination between vessel and perfusion densities. This method can reveal a change in the proportion of perfusion density from vessels larger than capillaries, even when mean values do not differ. This change could reflect compensatory arterial vasodilatation as a response to capillary dropout in the initial stages of retinal vascular diseases before clinical retinopathy appears. The proposed method would allow the estimation of the changes in the composition of perfusion density without the need for other devices.

We describe the evaluation of a coefficient of determination between vessel and perfusion density of the parafoveal superficial capillary plexus to identify the contribution of vessels larger than capillaries to perfusion density.

Valutazione del contributo capillare e di altri vasi alla densità di perfusione maculare misurata con tomografia a coerenza ottica Angiografia

Parafoveal circulation of the superficial retinal capillary plexus is usually measured with vessel density, which determines the length of capillaries ...

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.

Un approccio standardizzato alla fotografia digitale extra-orale e intraorale

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.

Rilevamento e rimozione della resina composita colorata dei denti utilizzando la tecnica di identificazione assistita da fluorescenza

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.

Navigazione dinamica in endodonzia: preparazione guidata delle cavità di accesso mediante un sistema di navigazione miniaturizzato

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 ...

Valutazione del movimento del dente posteriore mascellare mediante sovrapposizione digitale

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.

Autore in primo piano: Valutazione del movimento 3D dei denti posteriori mascellari nel trattamento con allineatore trasparente

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.

Misurazione del movimento dei denti posteriori mascellari: una valutazione del modello utilizzando la sovrapposizione palatale e dentale

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