This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.

Informed consent was obtained from every patient before surgery. After the interventions anonymized retrospective data was used in this study.
1. Steps in the traditional workflow of dynamic navigation systems using labeled clip calibration method (only for use on jawbone with teeth):
<ol>
	<li>Attach a radiopaque fixation clip to the teeth of the jawbone where the treatment is to be performed (maxilla/mandible) using a thermoplastic material.</li>
	<li>Make a CBCT examination of the patient with a labeled clip in the mouth (CBCT, FOV 8 cm x 11 cm, 12 mA, 95 kV).</li>
	<li>Plan the position of the implant according to the prosthetic architecture with the appropriate software.</li>
	<li>Calibrate the device (each step can be activated on display with the Play symbol).
	<ol>
		<li>Register the handpiece.
		<ol>
			<li>Calibrate handpiece chuck.</li>
			<li>Calibrate the rotating marker-disc inserted into the handpiece.</li>
			<li>Assemble the arm between the patient tracker and the labeled clip, and calibrate it.</li>
		</ol>
		</li>
	</ol>
	</li>
	<li>Check calibration by holding the tip of the measured drill to the surface of the labeled clip (Figure 1).
	<ol>
		<li>Fix the labeled clip holding the optical marker (tracker) on the teeth of the upper or lower jaw (on which jaw the implant placement occurs). Ensure to insert the clip in the same position registered on the preoperative CBCT.</li>
		<li>Calibrate the labeled clip by touching the metal spheres of the clip with the pivot of the probe.</li>
	</ol>
	</li>
	<li>Perform the navigated implant placement in local anesthesia, injecting 2 mL of articain (80 mg/2 mL articain/ampoule).
	<ol>
		<li>Measure the drill length (touching the drill to the go plate) (Figure 2).</li>
		<li>Check the real-time visual accuracy before drilling (touching the drill to any tooth surface and checking that it is in the same position on the monitor and the mouth).</li>
		<li>Determine the entry point of drilling. Explore the operation site without the flap.</li>
		<li>Drill the bone with dynamic navigation control (Figure 3, Figure 4, and Figure 5) .</li>
		<li>Measure the implant length (touching the implant to the go plate).</li>
		<li>Place the implant with the handpiece wearing the tracker controlled by the dynamic navigation system.</li>
		<li>Close the wound with 5.0 monofilament, nonabsorbable polypropylene suture, or fix the prefabricated prosthetic work.</li>
	</ol>
	</li>
	<li>Acquire control radiologic imaging (CBCT, FOV 8 cm x 11 cm, 12 mA, 95 kV).</li>
</ol>
2. Steps in the dynamic navigation systems using the tracer calibration method (not labeled method):
<ol>
	<li>Perform CBCT of the patient (without clip in the mouth).</li>
	<li>Plan the position of the implant according to the prosthetic architecture with the appropriate software.</li>
	<li>Calibrate the device as detailed in step 1.4.</li>
	<li>Calibrate the system without a labeled clip&#160;(not labeled method).
	<ol>
		<li>Transfer the plan of the implant surgical placement into the software of the used navigation system. Select the workspace on the 3D CT image of the navigation software.</li>
		<li>Fix the tracker on the teeth (with an unlabelled clip) or in case of an edentulous jaw with a special tracker-holding arm.</li>
		<li>Select the typical anatomical points (teeth or bone surface) on a 3D CT image of the navigation system (minimum three points).</li>
		<li>Identify the selected anatomical points in the mouth by touching them with a probe tool. (Figure 6).</li>
		<li>Perform refinement procedure on three to four areas by drawing on the surface of the anatomical structure with a probe.</li>
	</ol>
	</li>
	<li>Place the implant with navigation in local anesthesia, injecting 2 mL of articain (80 mg/2 mL articain/ampoule).
	<ol>
		<li>Measure the drill length (touching the drill to the go plate).</li>
		<li>Check the real-time visual accuracy before drilling (touching the drill to any tooth surface and checking that it is in the same position on the monitor and in the mouth).</li>
		<li>Determine the drilling point. Explore the operation site without the flap.</li>
		<li>Drill the bone with dynamic navigation control.</li>
		<li>Measure the implant length (touching the implant to the go plate).</li>
		<li>Place the implant with the handpiece wearing the tracker controlled by the dynamic navigation control system.</li>
		<li>Close the wound with 5.0 monofilament, nonabsorbable polypropylene suture or fix the prefabricated prosthetic work.</li>
	</ol>
	</li>
	<li>Make control radiologic imaging (CBCT, FOV 8 cm x 11 cm, 12 mA, 95 kV).</li>
</ol>

<ol>
	<li>Block, M. S., Emery, R. W., Cullum, D. R., Sheikh, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Implant+placement+is+more+accurate+using+dynamic+navigation.">Implant placement is more accurate using dynamic navigation.</a> Journal of Oral and Maxillofacial Surgery. 75 (7), 1377-1386 (2017).</li><li>Kaewsiri, D., Panmekiate, S., Subbalekha, K., Mattheos, N., Pimkhaokham, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+accuracy+of+static+vs.+dynamic+computer-assisted+implant+surgery+in+single+tooth+space:+A+randomized+controlled+trial.">The accuracy of static vs. dynamic computer-assisted implant surgery in single tooth space: A randomized controlled trial.</a> Clinical Oral Implants Research. 30 (6), 505-514 (2019).</li><li>Block, M. S., Emery, R. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Static+or+dynamic+navigation+for+implant+placement-choosing+the+method+of+guidance.">Static or dynamic navigation for implant placement-choosing the method of guidance.</a> Journal of Oral and Maxillofacial Surgery. 74 (2), 269-277 (2016).</li><li>Stefanelli, L. V., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Accuracy+of+a+novel+trace-registration+method+for+dynamic+navigation+surgery.">Accuracy of a novel trace-registration method for dynamic navigation surgery.</a> International Journal of Periodontics &amp; Restorative Dentistry. 40 (3), 427-435 (2020).</li><li>Mediavilla Guzman, A., Riad Deglow , E., Zubizarreta-Macho, A., Agustin-Panadero, R., Hernandez Montero, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Accuracy+of+computer-aided+dynamic+navigation+compared+to+computer-aided+static+navigation+for+dental+implant+placement:+An+in+vitro+study.">Accuracy of computer-aided dynamic navigation compared to computer-aided static navigation for dental implant placement: An in vitro study.</a> Journal of Clinical Medicine. 8 (12), 2123 (2019).</li><li>Sun, T. M., Lan, T. H., Pan, C. Y., Lee, H. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Dental+implant+navigation+system+guide+the+surgery+future.">Dental implant navigation system guide the surgery future.</a> Kaohsiung Journal of Medical Sciences. 34 (1), 56-64 (2018).</li><li>Wu, Y., Wang, F., Fan, S., Chow, J. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Robotics+in+dental+implantology.">Robotics in dental implantology.</a> Oral and Maxillofacial Surgery Clinics of North America. 31 (3), 513-518 (2019).</li><li>Block, M. S., Emery, R. W., Lank, K., Ryan, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Implant+placement+accuracy+using+dynamic+navigation.">Implant placement accuracy using dynamic navigation.</a> International Journal of Oral &amp; Maxillofacial Implants. 32 (1), 92-99 (2017).</li><li>Panchal, N., Mahmood, L., Retana, A., Emery, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Dynamic+navigation+for+dental+implant+surgery.">Dynamic navigation for dental implant surgery.</a> Oral and Maxillofacial Surgery Clinics of North America. 31 (4), 539-547 (2019).</li><li>Emery, R. W., Merritt, S. A., Lank, K., Gibbs, J. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Accuracy+of+dynamic+navigation+for+dental+implant+placement-model-based+evaluation.">Accuracy of dynamic navigation for dental implant placement-model-based evaluation.</a> Journal of Oral Implantology. 42 (5), 399-405 (2016).</li></ol>

All authors have disclosed any and all conflicts of interest.

In the labeled clip-used dynamic navigation implant placement system, the traditional workflow is done by clip calibration. There are three radiopaque metal spheres on the surface of the clip, which are clearly visible on the CBCT scan. In the case of the tracer calibration method, these metal spheres containing clips are neither necessary for the CBCT scanning nor system calibration. In cases with existing teeth, both the labeled and unlabelled clips can be used (two different calibration methods). The clip is attached ...

To increase the accuracy of dental implant placement and reduce the complications, a range of navigation techniques based on imaging studies have been developed. Preoperative imaging and special 3D implant planning software can be used to plan the exact position of the dental implant1,2.
The aim of implant surgery navigation is to accomplish a more anatomically precise placement of the dental implant to achieve the most ideal position, to reduce the risk of possible iatrogenic complications (nerve, vascular, bone, and sinus injuries). The navigated surgery decreases the invasiveness of the intervention (flapless surgery), which can lead to fewer complaints and faster recovery. The accurate implant placement is based on prior prosthetic planning (it is possible to perform the operation on the basis of a preoperative tooth installation) and the optimal implant positioning can help avoid bone grafting.
Nowadays, there are two types of computer-assisted implant (CAI) surgical placement navigation systems-static and dynamic navigation systems. Static navigation is a controlled implant placement method using a preplanned and prefabricated surgical template. Dynamic navigation is a preplanned computer-guided implant surgical placement method without a surgical template using optical control. The control procedure uses point cloud-based image registration to merge the virtual images with the real environment by applying 3D image overlay3.
DCAI systems make possible real-time, objectified instrument control within a GPS-like framework. Typically, they use optical tracking to detect and track the position of (optical) reference markers placed over the patient and the surgical instruments, and provide continuous visual feedback on the implant surgical placement process1,2.
The movement and position of the surgical instrument during surgery can be monitored live on a three-dimensional image on a monitor. During the procedure, the camera system allows continuous monitoring and comparison of the position of the patient&#39;s jawbone and the position of the surgical instrument.
There are two types of dynamic navigation systems: one is the passive system, in which case the registration devices (reference bases) reflect light emitted from the light source back to the stereo cameras; the other is the active system, where the registration devices emit light which is followed by stereo cameras4,5.
The next level of dynamic navigation systems uses servo motors to guide the surgeon&#39;s hand with tactile stimuli so that the device with robotic arms can determine the surgeon&#39;s movements or even replace them completely in the distant future4,5,6,7.

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>DTX Implant Studio Software</td>
			<td>Nobel Biocare</td>
			<td>106182</td>
			<td>3D surgical planing software</td>
		</tr>
		<tr>
			<td>MeshLab</td>
			<td>ISTI - CNR research center</td>
			<td>2020.12</td>
			<td>3D mesh processing software</td>
		</tr>
		<tr>
			<td>Nobel Replace CC implant</td>
			<td>Nobel Biocare</td>
			<td>37285</td>
			<td>Implant</td>
		</tr>
		<tr>
			<td>X-Guide</td>
			<td>X-Nav - Nobel Biocare</td>
			<td>SN00001310</td>
			<td>dinamic navigation surgery system</td>
		</tr>
		<tr>
			<td>X-Guide - XClip</td>
			<td>X-Nav - Nobel Biocare</td>
			<td>XNVP008381</td>
			<td>3D navigation registration device</td>
		</tr>
		<tr>
			<td>X-Guide planing software</td>
			<td>X-Nav - Nobel Biocare</td>
			<td>XNVP008296</td>
			<td>3D surgical planing and operating software</td>
		</tr>
		<tr>
			<td>X-Mark probe</td>
			<td>X-Nav - Nobel Biocare</td>
			<td>XNVP008886</td>
			<td>3D navigation registration tool</td>
		</tr>
		<tr>
			<td>PaX-i3D Smart</td>
			<td>Vatech</td>
			<td></td>
			<td>CBCT</td>
		</tr>
		<tr>
			<td>Prolene 5.0</td>
			<td></td>
			<td></td>
			<td>5.0 monofilament, nonabsorbable polypropylene suture</td>
		</tr>
	</tbody>
</table>

dynamic navigation for dental implant placement

In modern implantology, the application of surgical navigation systems is becoming increasingly important. In addition to static surgical navigation methods, a guide-independent dynamic navigation implant placement procedure is becoming more widespread. The procedure is based on computer-guided dental implant placement utilizing optical control. This work aims to demonstrate the technical steps of a new dynamic computer-aided implant surgery (DCAIS)&#160;system (design, calibration, surgery) and check the accuracy of the results. Based on cone-beam computed tomography (CBCT) scans, the exact positions of implants are determined with dedicated software. The first step of the operation is the calibration of the navigation system, which can be performed in two ways: 1) based on CBCT images taken with a marker or 2) based on CBCT images without markers. Implants are inserted with the aid of real-time navigation according to the preoperative plans. The accuracy of the interventions can be evaluated based on postoperative CBCT images. The preoperative images containing the planned positions of the implants and postoperative CBCT images were compared based on the angulation (degree), platform, and apical deviation (mm) of the implants. To evaluate the data, we calculated the standard deviation (SD), mean, and standard error of the mean (SEM) of deviations within planned and performed implant positions. Differences between the two calibration methods were compared based on this data. Based on the interventions performed so far, the use of DCAIS allows for high-precision implant placement. A calibration system that does not require labeled CBCT recording allows for surgical intervention with similar accuracy as a system that uses labeling. The accuracy of the intervention can be improved by training.

To use DCAIS correctly, the system must be calibrated. There are several calibration methods that can affect the accuracy of the implant placement. This study aimed to assess the potential impact of different calibration methods on the accuracy of DCAIS.
Based on the interventions performed so far, the use of DCAIS allows a high-precision implant placement. In our early studies, we compared 41 clip calibrated dynamic navigated implant placements with 17 tracer calibrated dynamic navigated impl...

Watch this Scientific Journal Video about Dynamic Navigation for Dental Implant Placement at JoVE.com

Dynamic Navigation for Dental Implant Placement

Dynamic computer-aided implant surgery (DCAIS) is a controlled implant surgical placement method performed without a surgical template using optical control. The real-time intraoperative control of movement and position of the surgical device simplifies the procedure and gives more freedom to the surgeon, providing similar precision as static navigation methods.

In modern implantology, the application of surgical navigation systems is becoming increasingly important. In addition to static surgical navigation ...

dynamic-navigation-for-dental-implant-placement

Research

JoVE Journal

Medicine

3.4K Views.  Semmelweis University. Dynamic computer-aided implant surgery (DCAIS) is a controlled implant surgical placement method performed without a surgical template using optical control. The real-time intraoperative control of movement and position of the surgical device simplifies the procedure and gives more freedom to the surgeon, providing similar precision as static navigation methods. 

Video: Dynamic Navigation for Dental Implant Placement

Shrinkage of Dental Composite in Simulated Cavity Measured with 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 understand where and how shrinkage strain and stress develop in such restored teeth, Digital Image Correlation (DIC) was used to provide a comprehensive view of the displacement and strain distributions within model restorations that had undergone polymerization shrinkage.
Specimens with model cavities were made of cylindrical glass rods with both diameter and length being 10 mm. The dimensions of the mesial-occlusal-distal (MOD) cavity prepared in each specimen measured 3 mm and 2 mm in width and depth, respectively. After filling the cavity with resin composite, the surface under observation was sprayed with first a thin layer of white paint and then fine black charcoal powder to create high-contrast speckles. Pictures of that surface were then taken before curing and 5 min after. Finally, the two pictures were correlated using DIC software to calculate the displacement and strain distributions.
The resin composite shrunk vertically towards the bottom of the cavity, with the top center portion of the restoration having the largest downward displacement. At the same time, it shrunk horizontally towards its vertical midline. Shrinkage of the composite stretched the material in the vicinity of the &#8220;tooth-restoration&#8221; interface, resulting in cuspal deflections and high tensile strains around the restoration. Material close to the cavity walls or floor had direct strains mostly in the directions perpendicular to the interfaces. Summation of the two direct strain components showed a relatively uniform distribution around the restoration and its magnitude equaled approximately to the volumetric shrinkage strain of the material.

In order to understand the spatial development of polymerization shrinkage stress in dental resin-composite restorations, Digital Image Correlation was used to provide full-field displacement/strain measurement of restored model glass cavities by correlating images of the restoration taken before and after polymerization.

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

Oral Biofilm Sampling for Microbiome Analysis in Healthy Children

Oral biofilm and its molecular analysis provide a basis for investigating various dental research and clinical questions. Knowledge of biofilm composition leads to a better understanding of cariogenic and periopathogenic mechanisms. Microbial changes taking place in the oral cavity during childhood are of interest for several reasons. The evolution of the child oral microbiota and shifts in its composition need to be analyzed further to understand and possibly prevent the onset of disease. At the same time, advanced knowledge of the natural composition of oral biofilm is needed. Early stages of caries-free permanent dentition with healthy gums provide a widely unaffected subgingival habitat that can serve as an in situ baseline for studying features of oral health and disease. Analysis of children's oral biofilm during different stages in life is thus an important theme in the field. Modern molecular analysis methods can provide comprehensive information about the bacterial diversity of such biofilms. To enable microbiota data comparison, it is important to standardize each step in the procedure for molecular data generation. This procedure spans from clinical sampling, Next Generation Sequencing (NGS), bioinformatic data processing, to taxonomic interpretation. One of the most critical factors here is biofilm sampling. Sampling in children is even more challenging in particular due to limited space in subgingival areas. We thus focus on the use of paper points for subgingival sampling. This article provides a detailed protocol for oral biofilm sampling of the subgingival sulcus, the mucosa, and saliva in children.

Changes in the oral microbiome throughout childhood are of growing interest. Comparison of different microbiome studies reveals a lack of standardized sampling protocols. Limited space makes sampling the sound subgingival sulcus of children challenging. Paper point sampling is presented here in detail as the method of choice for this area.

Oral biofilm and its molecular analysis provide a basis for investigating various dental research and clinical questions. Knowledge of biofilm composition ...

Oral Biofilm Formation on Different Materials for Dental Implants

Dental implants and their prosthetic components are prone to bacterial colonization and biofilm formation. The use of materials that provides low microbial adhesion may reduce the prevalence and progression of peri-implant diseases. In view of the oral environment complexity and oral biofilm heterogeneity, microscopy techniques are needed that can enable a biofilm analysis of the surfaces of teeth and dental materials. This article describes a series of protocols implemented for comparing oral biofilm formation on titanium and ceramic materials for prosthetic abutments, as well as the methods involved in oral biofilms analyses at the morphological and cellular levels. The in situ model to evaluate oral biofilm formation on titanium and zirconia materials for dental prosthesis abutments as described in this study provides a satisfactory preservation of the 48 h biofilm, thereby demonstrating methodological adequacy. Multiphoton microscopy allows the analysis of an area representative of the biofilm formed on the test materials. In addition, the use of fluorophores and the processing of the images using multiphoton microscopy allows the analysis of the bacterial viability in a very heterogeneous population of microorganisms. The preparation of biological specimens for electron microscopy promotes the structural preservation of biofilm, images with good resolution, and no artifacts.

Here, we present a protocol to evaluate oral biofilm formation on titanium and zirconia materials for dental prosthesis abutments, including the analysis of bacterial cells viability and morphological characteristics. An in situ model associated with powerful microscopy techniques is used for the oral biofilm analysis.

Dental implants and their prosthetic components are prone to bacterial colonization and biofilm formation. The use of materials that provides low ...

Electromagnetic Navigation Transthoracic Nodule Localization for Minimally Invasive Thoracic Surgery

The increased use of chest computed tomography (CT) has led to an increased detection of pulmonary nodules requiring diagnostic evaluation and/or excision. Many of these nodules are identified and excised via minimally invasive thoracic surgery; however, subcentimeter and subsolid nodules are frequently difficult to identify intra-operatively. This can be mitigated by the use of electromagnetic transthoracic needle localization. This protocol delineates the step-by-step process of electromagnetic localization from the pre-operative period to the postoperative period and is an adaptation of the electromagnetically guided percutaneous biopsy previously described by Arias et al. Pre-operative steps include obtaining a same day CT followed by the generation of a three-dimensional virtual map of the lung. From this map, the target lesion(s) and an entry site are chosen. In the operating room, the virtual reconstruction of the lung is then calibrated with the patient and the electromagnetic navigation platform. The patient is then sedated, intubated, and placed in the lateral decubitus position. Using a sterile technique and visualization from multiple views, the needle is inserted into the chest wall at the prechosen skin entry site and driven down to the target lesion. Dye is then injected into the lesion and, then, continuously during needle withdrawal, creating a tract for visualization intra-operatively. This method has many potential benefits when compared to the CT-guided localization, including a decreased radiation exposure and decreased time between the dye injection and the surgery. Dye diffusion from the pathway occurs over time, thereby limiting intra-operative nodule identification. By decreasing the time to surgery, there is a decrease in wait time for the patient, and less time for dye diffusion to occur, resulting in an improvement in nodule localization. When compared to electromagnetic bronchoscopy, airway architecture is no longer a limitation as the target nodule is accessed via a transparenchymal approach. Details of this procedure are described in a step-by-step fashion.

Presented here is a protocol for lung nodule localization using dye marking via electromagnetically navigated transthoracic needle access. The technique described here can be accomplished in the peri-operative period to optimize nodule localization and to successful resection when performing minimally invasive thoracic surgery.

The increased use of chest computed tomography (CT) has led to an increased detection of pulmonary nodules requiring diagnostic evaluation and/or ...

Real-Time Dynamic Navigation System for the Precise Quad-Zygomatic Implant Placement in a Patient with a Severely Atrophic Maxilla

Zygomatic implants (ZIs) are an ideal way to address cases of a severely atrophic edentulous maxilla and maxilla defects because they replace extensive bone augmentation and shorten the treatment cycle. However, there are risks associated with the placement of ZIs, such as penetration of the orbital cavity or infra-temporal fossa. Furthermore, the placement of multiple ZIs makes this surgery risky and more difficult to perform. Potential intraoperative complications are extremely dangerous and may cause irreparable losses. Here, we describe a practical, feasible, and reproducible protocol for a real-time surgical navigation system for precisely placing quad-zygomatic implants in the severely atrophic maxilla of patients with residual bone that does not meet the requirements of conventional implants. Hundreds of patients have received ZIs at our department based on this protocol. The clinical outcomes have been satisfactory, the intraoperative and postoperative complications have been low, and the accuracy indicated by infusion of the designed image and postoperative three-dimensional image has been high. This method should be utilized during the entire surgical procedure to ensure ZI placement safety.

Here, we present a protocol to achieve precise quad-zygomatic implant placement in patients with severely atrophic maxilla using a real-time dynamic navigation system.

Zygomatic implants (ZIs) are an ideal way to address cases of a severely atrophic edentulous maxilla and maxilla defects because they replace extensive ...

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.

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 ...

A Retrograde Implantation Approach for Peritoneal Dialysis Catheter Placement in Mice

Murine models are employed to probe various aspects of peritoneal dialysis (PD), such as peritoneal inflammation and fibrosis. These events drive peritoneal membrane failure in humans, which remains an area of intense investigation due to its profound clinical implications in managing patients with end-stage kidney disease (ESKD). Despite the clinical importance of PD and its related complications, current experimental murine models suffer from key technical challenges that compromise the models&#39; performance. These include PD catheter migration and kinking and usually warrant earlier catheter removal. These limitations also drive the need for a greater number of animals to complete a study. Addressing these drawbacks, this study introduces technical improvements and surgical nuances to prevent commonly observed PD catheter complications in a murine model. Moreover, this modified model is validated by inducing peritoneal inflammation and fibrosis using lipopolysaccharide injections. In essence, this paper describes an improved method to create an experimental model of PD.

This article describes modifications of a procedure to implant a peritoneal dialysis catheter in a murine model to avoid major technical issues observed with the conventional techniques.

Murine models are employed to probe various aspects of peritoneal dialysis (PD), such as peritoneal inflammation and fibrosis. These events drive ...

Guided Endodontics: Three-Dimensional Planning and Template-Aided Preparation of Endodontic Access Cavities

Pulp canal obliterations (PCO) are often a consequence of dental trauma, such as luxation injuries. Even though dentin apposition is a sign of vital pulp, pulpitis or apical periodontitis may develop in the long term. Root canal treatment of teeth with severe PCO and pulpal or periapical pathosis is challenging for general practitioners and even for well-equipped endodontic specialists. To ensure detection of the calcified root canal and avoid excessive loss of tooth structure or root perforation, static navigation using templates ("Guided Endodontics") was introduced a few years ago. The general workflow includes three-dimensional imaging using cone-beam computed tomography (CBCT), a digital surface scan, and superimposition of both in a planning software. This is followed by virtual planning of the access cavity and the design of a template that will guide the drill to the desired target point. To do this, a true-to-scale virtual image of the drill must be placed in a way that the tip of the drill reaches the orifice of the calcified root canal. Once the template has been fabricated using computer-aided design and computer-aided manufacturing (CAD/CAM) or a 3D printer, guided preparation of the access cavity can be performed clinically. For research purposes, a postoperative CBCT image can be used to quantify the accuracy of the access cavity performed. This work aims to present the technique of static guided endodontics from imaging to clinical implementation.

Guided endodontics describes a template-aided approach for access cavity preparation. The procedure requires cone-beam computed tomography and a surface scan to produce a template. An incorporated sleeve guides the drill to the target point. This allows the preparation of minimally invasive endodontic access cavities in calcified teeth.

Pulp canal obliterations (PCO) are often a consequence of dental trauma, such as luxation injuries. Even though dentin apposition is a sign of vital pulp, ...

Augmented Reality Navigation-Guided Core Decompression for Osteonecrosis of Femoral Head

Osteonecrosis of the femoral head (ONFH) is a common joint disease in young and middle-aged patients, which seriously burdens their lives and work. For early-stage ONFH, core decompression surgery is a classical and effective hip preservation therapy. In traditional procedures of core decompression with Kirschner wire, there are still many problems such as X-ray exposure, repeated puncture verification, and damage to normal bone tissue. The blindness of the puncture process and the inability to provide real-time visualization are crucial reasons for these problems.
To optimize this procedure, our team developed an intraoperative navigation system on the basis of augmented reality (AR) technology. This surgical system can intuitively display the anatomy of the surgical areas and render preoperative images and virtual needles to intraoperative video in real-time. With the guide of the navigation system, surgeons can accurately insert Kirschner wires into the targeted lesion area and minimize the collateral damage. We conducted 10 cases of core decompression surgery with this system. The efficiency of positioning and fluoroscopy is greatly improved compared to the traditional procedures, and the accuracy of puncture is also guaranteed.

Augmented reality technology was applied to core decompression for osteonecrosis of the femoral head to realize real-time visualization of this surgical procedure. This method can effectively improve the safety and precision of core decompression.

Osteonecrosis of the femoral head (ONFH) is a common joint disease in young and middle-aged patients, which seriously burdens their lives and work. For ...

Semi-Automated Planimetric Quantification of Dental Plaque Using an Intraoral Fluorescence Camera

Dental plaque accumulation is quantified using clinical indices or, otherwise, the planimetric plaque index (PPI),&#160;which measures the relative area of a tooth that is covered by plaque deposits. Compared to clinical indices, the PPI has a higher discriminatory power, but traditional planimetry is a time-consuming analysis, as the plaque-covered and clean tooth areas have to be determined manually for each image using image-processing software. Here, we present a method for the semi-automated planimetric quantification of dental plaque, which allows for the rapid processing of up to 1,000 images simultaneously. The method exploits the enhanced contrast between disclosed plaque, sound tooth surfaces, and soft tissues in fluorescence images acquired with an intraoral camera. Careful execution of the clinical procedures and accurate image acquisition are crucial steps for the successful semi-automated identification of the plaque-covered areas. The method is suitable for planimetry on sound facial and oral tooth surfaces, on most composite resin restorations, and on teeth with orthodontic brackets, but not on metallic restorations. Compared to traditional PPI recordings, semi-automated planimetry considerably reduces the amount of time spent on the analysis, as well as the subjective human input, thus increasing the reproducibility of planimetric measurements.

This study presents a semi-automated digital image analysis procedure for the planimetric quantification of disclosed dental plaque based on images acquired with an intraoral fluorescence camera. The method allows for the rapid and reliable quantification of dental plaque in the research environment.

Dental plaque accumulation is quantified using clinical indices or, otherwise, the planimetric plaque index (PPI),&#160;which measures the relative area ...