1. Articles in category: Dentistry

    1-24 of 307 1 2 3 4 ... 11 12 13 »
    1. Assessment of early occlusal caries pre- and post- sealant application—An imaging approach

      Assessment of early occlusal caries pre- and post- sealant application—An imaging approach

      Background and Objective Clinicians have difficulty assessing and monitoring early occlusal caries. Traditional clinical exam and radiographs are unable to detect the subtle alterations in enamel indicative of de- or re-mineralization, particularly under dental sealants. Although clinicians have used laser fluorescence (LF) to address this gap, this modality has demonstrated weak correlation with histology. The International Caries Detection and Assessment System (ICDAS-II) has demonstrated high sensitivity and specificity for caries detection, but since it is based on visual assessment, it is of no use in areas beneath the most commonly used dental sealants which are opaque. Optical coherence tomography (OCT ...

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    2. UCSF Receives NIH Grant for Selective Ablation of Dental Caries and Composites

      UCSF Receives NIH Grant for Selective Ablation of Dental Caries and Composites

      The University of California at San Francisco received a 2014 NIH Grant for $394,375 for Selective Ablation of Dental Caries and Composites. The principal investigator is Daniel Fried. The program began in 2009 and ends in 2018. below is a summary of the proposed work. The overall objective of this proposed research is to increase our fundamental understanding of the interaction of high intensity laser radiation with dental hard tissues and apply that knowledge to the development of laser based methods that selectively remove dental caries and composite restorative materials using an integrated approach of computer-controlled laser beam scanning ...

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    3. Nondestructive observation of teeth post core space using optical coherence tomography: a pilot study

      Nondestructive observation of teeth post core space using optical coherence tomography: a pilot study

      Coronal tooth lesions, such as caries, enamel cracking, and composite resin restoration cavities, have been observed by optical coherence tomography (OCT). This pilot study was performed to verify whether OCT could reveal details of root canals filled with resin core build-up. A dual-cure, one-step, self-etch adhesive system-bonding agent (Clearfil Bond SE ONE, Kuraray Noritake Dental) and dual-cure resin composite core material (Clearfil DC Core Automix ONE, Kuraray Noritake Dental) were used according to the manufacturer’s instructions in root canals. OCT was performed at three stages of the core build-up: after the post space preparation, after bonding application, and after ...

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      Mentions: Osaka University
    4. Dental imaging using laminar optical tomography and micro CT

      Dental imaging using laminar optical tomography and micro CT

      Dental lesions located in the pulp are quite difficult to identify based on anatomical contrast, and, hence, to diagnose using traditional imaging methods such as dental CT. However, such lesions could lead to functional and/or molecular optical contrast. Herein, we report on the preliminary investigation of using Laminar Optical Tomography (LOT) to image the pulp and root canals in teeth. LOT is a non-contact, high resolution, molecular and functional mesoscopic optical imaging modality. To investigate the potential of LOT for dental imaging, we injected an optical dye into ex vivo teeth samples and imaged them using LOT and micro-CT ...

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    5. High contrast optical imaging methods for image guided laser ablation of dental caries lesions

      High contrast optical imaging methods for image guided laser ablation of dental caries lesions

      Laser based methods are well suited for automation and can be used to selectively remove dental caries to minimize the loss of healthy tissues and render the underlying enamel more resistant to acid dissolution. The purpose of this study was to determine which imaging methods are best suited for image-guided ablation of natural non-cavitated carious lesions on occlusal surfaces. Multiple caries imaging methods were compared including near-IR and visible reflectance and quantitative light fluorescence (QLF). In order for image-guided laser ablation to be feasible, chemical and physical modification of tooth surfaces due to laser irradiation cannot greatly reduce the contrast ...

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    6. Monitoring the inhibition of erosion by a CO2 laser with OCT

      Monitoring the inhibition of erosion by a CO2 laser with OCT

      Since optical coherence tomography (OCT) is well suited for measuring small dimensional changes on tooth surfaces, OCT has great potential for monitoring tooth erosion. Previous studies have shown that enamel areas ablated by a carbon dioxide laser manifested lower rates of erosion compared to the nonablated areas. The purpose of this study was to develop a model to monitor erosion in vitro that could potentially be used in vivo. Teeth surfaces were irradiated with a carbon dioxide laser at low sub-ablative fluence to create an acid-resistant reference layer without damaging the enamel. The laser treated areas were compared with the ...

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    7. Integral ceramic superstructure evaluation using time domain optical coherence tomography

      Integral ceramic superstructure evaluation using time domain optical coherence tomography

      Optical Coherence Tomography (OCT) is a non-invasive low coherence interferometry technique that includes several technologies (and the corresponding devices and components), such as illumination and detection, interferometry, scanning, adaptive optics, microscopy and endoscopy. From its large area of applications, we consider in this paper a critical aspect in dentistry - to be investigated with a Time Domain (TD) OCT system. The clinical situation of an edentulous mandible is considered; it can be solved by inserting 2 to 6 implants. On these implants a mesostructure will be manufactured and on it a superstructure is needed. This superstructure can be integral ceramic; in ...

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    8. Automated detection of remineralization in simulated enamel lesions with PS-OCT

      Automated detection of remineralization in simulated enamel lesions with PS-OCT

      Previous in vitro and in vivo studies have demonstrated that polarization-sensitive optical coherence tomography (PS-OCT) can be used to nondestructively image the subsurface structure and measure the thickness of the highly mineralized transparent surface zone of caries lesions. There are structural differences between active lesions and arrested lesions, and the surface layer thickness may correlate with activity of the lesion. The purpose of this study was to develop a method that can be used to automatically detect and measure the thickness of the transparent surface layer in PS-OCT images. Automated methods of analysis were used to measure the thickness of ...

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    9. Enhancing the detection of hidden occlusal caries lesions with OCT using high index liquids

      Enhancing the detection of hidden occlusal caries lesions with OCT using high index liquids

      In a previous study, we investigated the influence of several high refractive index fluids on the performance of polarization sensitive optical coherence tomography (PS-OCT). That study showed that these liquids can increase the effective imaging depth and lesion contrast. Other in vitro and in vivo studies have shown that OCT can be used to show whether occlusal lesions have penetrated to the dentinal-enamel junction (DEJ) and spread laterally under the enamel. The purpose of this study was to determine if high index fluids can enhance the ability of OCT to detect hidden occlusal lesions and show if these lesions have ...

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    10. Longitudinal monitoring of demineralization peripheral to orthodontic brackets using cross polarization optical coherence tomography

      Longitudinal monitoring of demineralization peripheral to orthodontic brackets using cross polarization optical coherence tomography

      Objectives The aim of this study was to test the hypothesis that cross-polarization optical coherence tomography (CP-OCT) can be used to longitudinally monitor demineralization peripheral to orthodontic brackets in an extended clinical study. Methods A high-speed CP-OCT system was used to acquire 3D volumetric images of the area at the base of orthodontic brackets over a period of 12-months after placement. The reflectivity was measured at 3-month intervals for 12-months to determine if there was increased demineralization. Two teeth were monitored on twenty test subjects and the brackets were bonded using two types of adhesives This was a randomized controlled ...

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    11. Characterization of transparent dentin in attrited teeth using optical coherence tomography

      Characterization of transparent dentin in attrited teeth using optical coherence tomography

      Attrition and wear of tooth surface occur with aging and result in loss of enamel, with exposure and histological changes in dentin. Dealing with attrited teeth and restoration of the lost tissue are clinically challenging. The main objective of this study is to characterize the exposed transparent dentin in the occlusal surface of attrited teeth by optical coherence tomography (OCT). Naturally attrited, extracted human teeth with occlusal-transparent dentin were investigated in comparison to sound and carious teeth. The teeth were subjected to OCT imaging and then cross-sectioned and polished. OCT B-scans were compared to light microscopy images of the same ...

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    12. Zirconia enriched dental adhesive: A solution for OCT contrast enhancement. Demonstrative study by synchrotron radiation microtomography

      Zirconia enriched dental adhesive: A solution for OCT contrast enhancement. Demonstrative study by synchrotron radiation microtomography

      Objective The major aim of this study was to prove the capability of the optical coherence tomography (OCT) method in visualizing the integrity of the adhesive fillings and of the interfaces between the adhesive, tooth structures and composite resin. As zirconium dioxide was added to the composition of the adhesive layer in order to strengthen the backscattered light in the OCT investigation, for a better visualization of the interfaces, the determination of a proper zirconia concentration was another aim of our study. Method Several class II cavities were prepared in human premolars and were filled with dental adhesive containing different ...

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    13. Optical coherence tomography examination of the effect of S-PRG filler extraction solution on the demineralization of bovine ename

      Optical coherence tomography examination of the effect of S-PRG filler extraction solution on the demineralization of bovine ename

      The purpose of this study was to determine the effect of PRG filler extraction solution on the demineralization of enamel using optical coherence tomography (OCT). Bovine enamel was treated with lactic acid buffer solution and then placed in artificial saliva (De group). In the second group, specimens were stored in PRG filler extraction solution followed by immersion in lactic acid buffer solution (PRG group). In the control group, specimens were simply stored in artificial saliva. From the OCT image, the peak intensity (dB) and width at (1/e 2 ) were obtained, and the integrated value was calculated. The data were ...

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    14. The Role of Novel Biophotonic Technique in Characterization of the Newly Developed Nanotechnology based Dental Composites (Thesis)

      The Role of Novel Biophotonic Technique in Characterization of the Newly Developed Nanotechnology based Dental Composites (Thesis)

      [Background and Objective]: Polymerization shrinkage and the associated contraction stresses are the major shortcoming of dental composites in dentistry, which may affect the bonding performance and result in gap formation at the tooth-restoration interface. Non-destructive assessment and monitoring of these defects are critically important. The aim of this study is to assess the toothrestoration interface and composite adaptation using swept source optical coherence tomography (SS-OCT) in combination of microtensile bond strength (MTBS) and to confirm the findings with confocal laser scanning microscope (CLSM) and scanning electron microscopy (SEM). [Materials and Methods]: Standard round class-I cavities were prepared in human premolar ...

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      Mentions: Turki Bakhsh
    15. Measuring Initial Enamel Erosion with Quantitative Light-Induced Fluorescence and Optical Coherence Tomography: An in vitro Validation Study

      Measuring Initial Enamel Erosion with Quantitative Light-Induced Fluorescence and Optical Coherence Tomography: An in vitro Validation Study

      Background: Measurement of initial enamel erosion is currently limited to in vitro methods. Optical coherence tomography (OCT) and quantitative light-induced fluorescence (QLF) have been used clinically to study advanced erosion. Little is known about their potential on initial enamel erosion. Objectives: To evaluate the sensitivity of QLF and OCT in detecting initial dental erosion in vitro. Methods: 12 human incisors were embedded in resin except for a window on the buccal surface. Bonding agent was applied to half of the window, creating an exposed and non-exposed area. Baseline measurements were taken with QLF, OCT and surface microhardness. Samples were immersed ...

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    16. Detection of occlusal caries in primary teeth using swept source optical coherence tomography

      Detection of occlusal caries in primary teeth using swept source optical coherence tomography

      This study aimed to investigate swept source optical coherence tomography (SS-OCT) as a detecting tool for occlusal caries in primary teeth. At the in vitro part of the study, 38 investigation sites of occlusal fissures (noncavitated and cavitated) were selected from 26 extracted primary teeth and inspected visually using conventional dental equipment by six examiners without any magnification. SS-OCT cross-sectional images at 1330-nm center wavelength were acquired on the same locations. The teeth were then sectioned at the investigation site and directly viewed under a confocal laser scanning microscope (CLSM) by two experienced examiners. The presence and extent of caries ...

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    17. Driving OCT into Dentistry

      Driving OCT into Dentistry

      The first international symposium on optical coherence tomography (OCT) in dentistry highlighted the many advantages of optical diagnostics over current "gold standard" technologies, including improved safety and earlier detection of decay. Stakeholders are now taking steps that will help this modality take root—and eventually improve patient outcomes. Considering the safety concerns associated with x-rays, newer optical diagnostics are particularly valuable in cases where frequent monitoring improves patient outcomes. Dentistry is one such case, and attendees at the first international Symposium on Optical Coherence Tomography (OCT) in Dentistry (June 20–21, 2013; Tokyo, Japan) came away with substantive evidence of ...

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    18. Temperature variation in metal ceramic technology analyzed using time domain optical coherence tomography

      Temperature variation in metal ceramic technology analyzed using time domain optical coherence tomography

      The quality of dental prostheses is essential in providing good quality medical services. The metal ceramic technology applied in dentistry implies ceramic sintering inside the dental oven. Every ceramic material requires a special sintering chart which is recommended by the producer. For a regular dental technician it is very difficult to evaluate if the temperature inside the oven remains the same as it is programmed on the sintering chart. Also, maintaining the calibration in time is an issue for the practitioners. Metal ceramic crowns develop a very accurate pattern for the ceramic layers depending on the temperature variation inside the ...

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    19. Imaging of noncarious cervical lesions by means of a fast swept source optical coherence tomography system

      Imaging of noncarious cervical lesions by means of a fast swept source optical coherence tomography system

      Non-carious cervical lesions (NCCL) are defined as the loss of tooth substance at the cemento-enamel junction and are caused by abrasion, erosion and/or occlusal overload. In this paper we proved that our fast swept source OCT system is a valuable tool to track the evolution of NCCL lesions in time. On several extracted bicuspids, four levels of NCCL were artificially created. After every level of induced lesion, OCT scanning was performed. B scans were acquired and 3D reconstructions were generated. The swept source OCT instrument used in this study has a central wavelength of 1050 nm, a sweeping range ...

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    20. The advantages of a swept source optical coherence tomography system in the evaluation of occlusal disorders

      The advantages of a swept source optical coherence tomography system in the evaluation of occlusal disorders

      Occlusal disorders are characterized by multiple dental and periodontal signs. Some of these are reversible (such as excessive tooth mobility, fremitus, tooth pain, migration of teeth in the absence of periodontitis), some are not (pathological occlusal/incisal wear, abfractions, enamel cracks, tooth fractures, gingival recessions). In this paper we prove the advantages of a fast swept source OCT system in the diagnosis of pathological incisal wear, a key sign of the occlusal disorders. On 15 extracted frontal teeth four levels of pathological incisal wear facets were artificially created. After every level of induced defect, OCT scanning was performed. B scans ...

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    21. Monitoring the remineralization of early simulated lesions using a pH cycling model with CP-OCT

      Monitoring the remineralization of early simulated lesions using a pH cycling model with CP-OCT

      If caries lesions are detected early enough they can be arrested by chemical intervention and dietary changes without the need for chemical intervention. Optical coherence tomography is ideally suited to monitor the changes that occur in caries lesions as a result of nonsurgical intervention, since OCT can nondestructively image the internal structure of the lesion. One of the most important changes that occurs in a lesion is preferential deposition of mineral in the outer surface zone. The deposition creates a highly mineralized and weakly scattering surface zone that is clearly visible in OCT images. Since this zone is near the ...

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    22. Use of 2D images of depth and integrated reflectivity to represent the severity of demineralization in cross-polarization optical coherence tomography

      Use of 2D images of depth and integrated reflectivity to represent the severity of demineralization in cross-polarization optical coherence tomography

      Several studies have demonstrated the potential of cross-polarization optical coherence tomography (CP-OCT) to quantify the severity of early caries lesions (tooth decay) on tooth surfaces. The purpose of this study is to show that 2D images of the lesion depth and the integrated reflectivity can be used to accurately represent the severity of early lesions. Simulated early lesions of varying severity were produced on tooth samples using simulated lesion models. Methods were developed to convert the 3D CP-OCT images of the samples to 2D images of the lesion depth and lesion integrated reflectivity. Calculated lesion depths from OCT were compared ...

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    23. Towards a bimodal proximity sensor for in situ neurovascular bundle detection during dental implant surgery

      Towards a bimodal proximity sensor for in situ neurovascular bundle detection during dental implant surgery

      Proof of concept results are presented towards an in situ bimodal proximity sensor for neurovascular bundle detection during dental implant surgery using combined near infrared absorption (NIR) and optical coherence tomography (OCT) techniques. These modalities are shown to have different sensitivity to the proximity of optical contrast from neurovascular bundles. NIR AC and DC signals from the pulsing of an artery enable qualitative ranging of the bundle in the millimeter range, with best sensitivity around 0.5-3mm distance in a custom phantom setup. OCT provides structural mapping of the neurovascular bundle at sub-millimeter distances in an ex vivo human jaw ...

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    24. Evaluation of metal-polymeric fixed partial prosthesis using optical coherence tomography

      Evaluation of metal-polymeric fixed partial prosthesis using optical coherence tomography

      Metal-Polymeric fixed partial prosthesis is the usual prosthetic treatment for many dental patients. However, during the mastication the polymeric component of the prosthesis is fractured and will be lost. This fracture is caused by the material defects or by the fracture lines trapped inside the esthetic components of the prosthesis. This will finally lead to the failure of the prosthetic treatment. Nowadays, there is no method of identification and forecast for the materials defects of the polymeric materials. The aim of this paper is to demonstrate the capability of Optical Coherence Tomography (OCT) as a non-invasive clinical method that can ...

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    1-24 of 307 1 2 3 4 ... 11 12 13 »
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