1. Articles in category: Dentistry

    1-24 of 272 1 2 3 4 ... 10 11 12 »
    1. Fossilized Teeth as a New Robust and Reproducible Standard for Polarization-Sensitive Optical Coherence Tomography

      Fossilized Teeth as a New Robust and Reproducible Standard for Polarization-Sensitive Optical Coherence Tomography

      A clinical need exists for a cheap and efficient standard for polarization sensitive optical coherence tomography (PS-OCT). We utilize prehistoric fossilized teeth from the Megalodon shark and European horse as an unconventional, yet robust standard. Given their easy accessibility and the microstructural consistency conferred by the process of fossilization, they provide a means of calibration to reduce error from sources such as catheter bending and temperature changes. We tested the maximum difference in birefringence values in each tooth and found the fossilized teeth to be fast and repeatable. The results were compared to measurements from bovine meniscus, tendon, and destroyed ...

      Read Full Article
    2. Symposium on Dental OCT June 20th 2013 in Tokyo, Japan.

      Symposium on Dental OCT June 20th 2013 in Tokyo, Japan.

      Tokyo Medial and Dental University will hold a special symposium in Tokyo on June 20 (Thu) on the development and application of Optical Coherence Tomography in Dentistry. The symposium is sponsored by Tokyo Medical and Dental University, and some of the pioneers of dental OCT from Japan and US will talk about the latest developments in the field (see the list of speakers at http://www.tmdu.net/oct/ ) . All interested individuals including students, researchers and company representatives are invited to attend this event. Registration fees will be waived for those who pre-register by June 3 online at http://www ...

      Read Full Article
    3. National Research Council Canada Receives a 2013 NIH Grant for Validating OCT and Raman Spectroscopy for Assessment of Tooth De/Remineralization

      National Research Council Canada Receives a 2013 NIH Grant for Validating OCT and Raman Spectroscopy for Assessment of Tooth De/Remineralization

      National Research Council Canada Receives a 2013 NIH Grant for $245,305 for Validating OCT and Raman Spectroscopy for Assessment of Tooth De/Remineralization. The principal investigator is Lin-P'ing Choo-Smith. The program is part of a multiyear program that started in 2006 and ends in 2017. Below is a summary of the work. Dental caries continues to be prevalent in children and youth, with significant oral health disparities existing in some population groups. This disease arises when the balance between pathological factors (e.g. cariogenic bacteria) and protective factors (e.g. saliva flow) is tipped in favour of demineralization ...

      Read Full Article
    4. Monitoring remineralization of enamel subsurface lesions by optical coherence tomography

      Monitoring remineralization of enamel subsurface lesions by optical coherence tomography

      Optical coherence tomography (OCT) is a potential clinical tool for enamel lesion monitoring. Swept-source OCT findings were compared with cross-sectional nanohardness findings of enamel. Subsurface bovine enamel lesions in three groups were subjected to (1) deionized water (control), (2) phosphoryl oligosaccharide of calcium (POs-Ca) or (3) POs-Ca with 1 ppm fluoride for 14 days. B-scans images were obtained at 1310-nm center wavelength on sound, demineralized and remineralized areas after 4, 7, and 14 days. The specimens were processed for cross-sectional nanoindentation. Reflectivity from enamel that had increased with demineralization decreased with remineralization. An OCT attenuation coefficient parameter ( μ t ), derived based ...

      Read Full Article
    5. Monitoring of enamel lesion remineralization by optical coherence tomography: an alternative approach towards signal analysis

      Monitoring of enamel lesion remineralization by optical coherence tomography: an alternative approach towards signal analysis

      Early detection, monitoring and remineralization repair of enamel lesions are top research priorities in the modern dentistry focusing on minimal intervention concept for caries management. We investigate the use of swept-source optical coherence tomography system (SS-OCT) without polarization-sensing at 1319 nm wavelength developed for clinical dentistry (Dental OCT System Prototype 2, Panasonic Healthcare Co., Ltd., Japan) in quantitative assessment of artificial enamel lesions and their remineralization. Bovine enamel blocks were subjected to demineralization to create subsurface lesions approximately 130 μm in depth over 2 weeks, and subjected to remineralization in solution containing bioavailable calcium and 1ppm fluoride at pH 6 ...

      Read Full Article
    6. Utilizing optical coherence tomography for CAD/CAM of indirect dental restorations

      Utilizing optical coherence tomography for CAD/CAM of indirect dental restorations

      Optical Coherence Tomography (OCT) has seen broad application in dentistry including early carious lesion detection and imaging defects in resin composite restorations. This study investigates expanding the clinical usefulness by investigating methods to use OCT for obtaining three-dimensional (3D) digital impressions, which can be integrated to CAD/CAM manufacturing of indirect restorations. 3D surface topography ‘before’ and ‘after’ a cavity preparation was acquired by an intraoral cross polarization swept source OCT (CP-OCT) system with a Micro-Electro-Mechanical System (MEMS) scanning mirror. Image registration and segmentation methods were used to digitally construct a replacement restoration that modeled the original surface morphology of ...

      Read Full Article
    7. Clinical monitoring of early caries lesions using cross polarization optical coherence tomography

      Clinical monitoring of early caries lesions using cross polarization optical coherence tomography

      New methods are needed for the nondestructive measurement of tooth demineralization and remineralization and to monitor the progression of incipient caries lesions (tooth decay) for effective nonsurgical intervention and to evaluate the performance of anti-caries treatments such as chemical treatments or laser irradiation. Studies have shown that optical coherence tomography (OCT) has great potential to fulfill this role, since it can be used to measure the depth and severity of early lesions with an axial resolution exceeding 10-μm. It is easy to apply in vivo and it can be used to image the convoluted topography of tooth occlusal surfaces ...

      Read Full Article
    8. Methods for monitoring erosion using optical coherence tomography

      Methods for monitoring erosion using optical coherence tomography

      Since optical coherence tomography is well suited for measuring small dimensional changes on tooth surfaces it has great potential for monitoring tooth erosion. The purpose of this study was to explore different approaches for monitoring the erosion of enamel. Application of an acid resistant varnish to protect the tooth surface from erosion has proven effective for providing a reference surface for in vitro studies but has limited potential for in vivo studies. Two approaches which can potentially be used in vivo were investigated. The first approach is to measure the remaining enamel thickness, namely the distance from the tooth surface ...

      Read Full Article
    9. 3D Assessment of Void and Gap Formation in Flowable Resin Composites Using Optical Coherence Tomography

      3D Assessment of Void and Gap Formation in Flowable Resin Composites Using Optical Coherence Tomography

      Purpose: To investigate the effect of composite type and cavity size on gap and void formation using optical coherence tomography (OCT). Materials and Methods: Class I cavities of two depths (2 mm or 4 mm; 4 mm diameter) were prepared, treated with Tri-S Bond (Kuraray Medical), and bulk filled with either Surefil SDR Flow (SF; Dentsply) or Clearfil Majesty LV (MJ; Kuraray Medical) to form four groups. After 24 h, the specimens were 3D scanned using swept-source OCT (Santec) with 1310 nm laser at a 20 kHz sweep rate. In OCT tomograms, the bonding interface and the bulk of the ...

      Read Full Article
    10. Comparing potential early caries assessment methods for teledentistry

      Comparing potential early caries assessment methods for teledentistry

      BACKGROUND: Optical caries detection has the potential to be incorporated in telehealth medicine for preventive dental screening. The objective of this study was to evaluate and compare visible and near infrared detection methods for identifying early non-cavitated ex vivo occlusal demineralization. METHODS: Six blinded examiners were used to compare the accuracy of the following three examinations in detecting occlusal demineralization: Midwest Caries IDTM (MID), visual photographic examination (CAM) and Cross Polarization Optical Coherence Tomography (CP-OCT). For each diagnostic method, two examiners assessed the extracted tooth samples 1--2 weeks apart. Teeth were then sectioned and lesion depth was confirmed (n = 42 ...

      Read Full Article
    11. Noninvasive cross-sectional imaging of proximal caries using swept-source optical coherence tomography (SS-OCT) in vivo

      Noninvasive cross-sectional imaging of proximal caries using swept-source optical coherence tomography (SS-OCT) in vivo

      The aim of this study was to determine the diagnostic accuracy of swept-source optical coherent tomography (SS-OCT) in detecting and estimating the depth of proximal caries in posterior teeth in vivo. SS-OCT images and bitewing radiographs were obtained from 86 proximal surfaces of 53 patients. Six examiners scored the locations according to a caries lesion depth scale (0–4) using SS-OCT and the radiographs. The results were compared with clinical observations obtained after the treatment. SS-OCT could detect the presence of proximal caries in tomograms that were synthesized based on the backscatter signal obtained from the proximal carious lesion through ...

      Read Full Article
    12. Examination of ceramic restorative material interfacial debonding using acoustic emission and optical coherence tomography

      Examination of ceramic restorative material interfacial debonding using acoustic emission and optical coherence tomography

      Objective CAD/CAM ceramic restorative material is routinely bonded to tooth substrates using adhesive cement. This study investigates micro-crack growth and damage in the ceramic/dentin adhesive interface under fatigue shear testing monitored using the acoustic emission (AE) technique with optical coherence tomography (OCT). Methods Ceramic/dentin adhesive samples were prepared to measure the shear bond strength (SBS) under static load. Fatigue shear testing was performed using a modified ISO14801 method. Loads in the fatigue tests were applied at 80%, 70%, and 60% of the SBS to monitor interface debonding. The AE technique was used to detect micro-crack signals in ...

      Read Full Article
      Mentions: Wen-Chuan Kuo
    13. Optical coherence tomography for debonding evaluation: An in-vitro qualitative study

      Optical coherence tomography for debonding evaluation: An in-vitro qualitative study

      Introduction The purpose of this research was to demonstrate the potential of the optical coherence tomography technique on the evaluation of changes and damages in the enamel structure caused by debonding and cleanup procedures. Methods Twin metal and ceramic brackets were bonded to the labial enamel surfaces of 120 incisors; the brackets were debonded 24 hours later. The anterior surfaces of the teeth were scanned, and optical coherence tomography images were captured in 2-dimensional and 3-dimensional modes before and after debonding and cleanup. A commercial spectral domain optical coherence tomography system with a 5-μm axial spatial resolution was used ...

      Read Full Article
    14. Detection of Root Surface Fractures with Swept-Source Optical Coherence Tomography (SS-OCT)

      Detection of Root Surface Fractures with Swept-Source Optical Coherence Tomography (SS-OCT)

      Objective: The purpose of this study was to compare optical coherence tomography (OCT) with the existing technologies, to assess its accuracy and utility in detecting vertical root fractures of extracted human teeth. Background data: The detection of root fractures in teeth that have undergone root canal treatment is challenging because of the great difficulty in differentiating these fractures from morphologic or radiographic anomalies. OCT methods are based on depth-resolved optical reflectivity and have been developed to reduce the invasiveness and radiation exposure inherent to other techniques. Methods: Twelve extracted human mandibular teeth (totaling 25 roots) that were free of caries ...

      Read Full Article
    15. Non-destructive characterization of voids in six flowable composites using swept-source optical coherence tomography

      Non-destructive characterization of voids in six flowable composites using swept-source optical coherence tomography

      Objective The aim of this study was to evaluate the void frequency ( V F ) and void volume ( V V ) in different flowable composites using swept-source optical coherence tomography (SS-OCT). Methods Standard class I cavities were prepared and filled with six different flowable composites: Clearfil Majesty LV (MJ; Kuraray), MI Flow (MW; GC), MI Fil (ML; GC), Beautifil flow plus (BF; Shofu), Palfique Estelite low flow (EL; Tokuyama) and Surefil SDR flow (SF; Dentsply). The restorations were scanned under OCT. The OCT tomograms were analyzed and average V F and V V per restoration for each composite were calculated. Scanning electron ...

      Read Full Article
    16. In vitro performance of different methods in detecting occlusal caries lesions

      In vitro performance of different methods in detecting occlusal caries lesions

      Early caries detection is essential for the implementation of preventive, therapeutic and intervention strategies within general dental practice. Objective: The aim of this study was to compare the in vitro performance of the International Caries Detection and Assessment System (ICDAS), Digital Photographs scored with ICDAS (ICDAS photographs), Fibre-Optic Trans-Ilumination (FOTI), Optical Coherence Tomography (OCT), SoproLife ® camera and two implementations of Quantitative Light-Induced Fluorescence a commercial (QLF-Inspektor Research systems) and a custom (QLF-Custom) system, to detect early and intermediate occlusal lesions. Methods: One hundred and twelve permanent extracted teeth were selected and assessed with each detection method. Histological validation was used ...

      Read Full Article
    17. Optical Coherence Tomography Apparatus And Optical Coherence Tomography Method

      Optical Coherence Tomography Apparatus And Optical Coherence Tomography Method

      The optical coherence tomography apparatus (1) comprises: a light source (11) that irradiates laser light; an optical splitter (12) that divides the laser light into measuring light that is irradiated on a subject (S) and reference light that is irradiated on a reference mirror (21); a probe (30) that receives scattered light returning after being scattered inside the subject (S); and an optical multiplexer (16) that combines reflected light returning after being reflected by the reference mirror (21) with the scattered light to generate interference light. The apparatus analyzes the interference light and generates an optical coherence tomographic image. The ...

      Read Full Article
    18. Validation of swept source optical coherence tomography (SS-OCT) for the diagnosis of smooth surface caries in vitro

      Validation of swept source optical coherence tomography (SS-OCT) for the diagnosis of smooth surface caries in vitro

      Objective An accurate evaluation of the extent of dental caries and possible progress of the lesion from enamel into dentin is very important in clinical dentistry. Dentists need an imaging technology that can noninvasively and reliably quantify the extent of caries. This study aimed to evaluate the effectiveness of non-polarized swept source optical coherence tomography (OCT) in evaluating the extent of caries on smooth enamel surfaces. Methods One-hundred and twenty-seven investigation sites on the enamel surfaces of 93 extracted teeth were selected randomly and examined visually. The presence and extent of caries were scored by experienced and inexperienced dentists using ...

      Read Full Article
    19. Estimation of the Enamel and Dentin Mineral Content from the Refractive Index

      Estimation of the Enamel and Dentin Mineral Content from the Refractive Index

      Recent advances in the field of optics have enabled accurate and localized measurement of optical properties of biological substrates. This work aimed to elucidate the relationship between the local refractive index ( n ) and mineral content (MC) of enamel and dentin. De- and remineralized lesions in bovine enamel and dentin blocks were sectioned into 300- to 400-µm-thick slices, and placed on a metal plate to capture images of sound, de- and remineralized regions transversely by optical coherence tomography. Mean n at each depth level of the lesion (20- or 40-µm steps for enamel or dentin) was measured by the ...

      Read Full Article
    20. Influence of dental resin material composition on cross-polarization-optical coherence tomography imaging

      Influence of dental resin material composition on cross-polarization-optical coherence tomography imaging
      The purpose of this study was to investigate cross-polarization-optical coherence tomography (CP-OCT) signal attenuation through different resin material compositions. Four distinct composite systems were used: Filtek supreme ultra (FSU) (3M ESPE), IPS empress direct (EMD) (Ivoclar Vivadent), estelite sigma quick (SQK) (Tokuyama Dental), and Z100 (3M ESPE). Cross-sectional images of different composite-demineralized phantoms ( n = 108 ) were collected using a 1310-nm intraoral cross-polarization swept source OCT (CP-OCT) imaging system. % T quantified the CP-OCT signal attenuation. Scanning electron microscopy, transmission electron microscopy, and energy-dispersive x-ray spectrometer chemical analysis was utilized to determine how different matrix/filler compositions affected attenuation of the near ...
      Read Full Article
    21. Concurrent Evaluation of Composite Internal Adaptation and Bond Strength in a Class-I Cavity

      Concurrent Evaluation of Composite Internal Adaptation and Bond Strength in a Class-I Cavity

      Objectives This study investigated class-I cavity floor adaptation by swept-source optical coherence tomography (OCT) in combination with microtensile bond strength (MTBS) using different filling methods. Methods Two adhesive systems; Tokuyama Bond Force and Tri-S Bond Plus were used in conjunction with a universal composite (Estelite Sigma Quick) placed either incrementally (oblique) or in bulk with or without a flowable composite lining (Palfique Estelite LV). Ten serial B-scan images were obtained throughout each cavity by OCT (center wavelength: 1319 nm). In order to evaluate adaptation defined as the cavity floor percentage showing no gap, a significant increase in the signal intensity ...

      Read Full Article
    22. Caries Detection Using Light-Based Diagnostic Tool

      Caries Detection Using Light-Based Diagnostic Tool

      Modern caries treatment concepts like caries management by risk assessment—CAMBRA—entail diagnosing early caries lesions in a precavitated stage to make it possible to reverse the caries process with remineralization and bacteria reduction efforts. Newer, sensitive caries diagnostic tools can serve not only for early detection but also for monitoring of caries lesions to confirm the success of prevention and remineralization efforts. This article describes light-based caries diagnostic tools, with emphasis on fluorescence-based techniques, and compares the most common available fluorescence-based tools with a standardized visual caries inspection system—the International Caries Detection and Assessment System (ICDAS II). Fluorescence ...

      Read Full Article
    23. Quantitative optical coherence tomography of fluid-filled oral mucosal lesions

      Quantitative optical coherence tomography of fluid-filled oral mucosal lesions

      The decision of selecting the most representative site for the biopsy of fluid-filled lesions can be difficult. This may be attributed to the poor delineation of the correct lesional site by clinical observation alone. In this study, optical coherence tomography is used to quantify the contrast between solid- and fluid-filled lesions by measuring the light intensity change at the tissue–fluid interface (intensity drop). This parameter was measured from sequential axial scans (n ≈ 106 per sample) of 3D optical coherence tomography (OCT) datasets from control tissues (n = 14) and fluid-filled lesions (n = 7) and displayed as a 2D-scaled intensity drop ...

      Read Full Article
    24. UCSF Receives NIH Grant for Optical Assessment of Caries Lesions Structure and Activity

      UCSF Receives NIH Grant for Optical Assessment of Caries Lesions Structure and Activity

      The University of California at San Francisco Received a 2012 NIH Grant for $39,413 for Optical Assessment of Caries Lesions Structure and Activity. The program started in 2012 and ends in 2016. Robert Lee is the Principal Investigator. Below is a summary of the work. The overall objective of this proposed research is to develop near-infrared (NIR) imaging methods for the detection and diagnosis of early dental caries (dental decay). New, more sophisticated diagnostic tools are needed for the detection and characterization of caries lesions in the early stages of development. If carious lesions are detected early enough, before ...

      Read Full Article
    1-24 of 272 1 2 3 4 ... 10 11 12 »
  1. Categories

    1. Applications:

      Art, Cardiology, Dentistry, Dermatology, Developmental Biology, Gastroenterology, Gynecology, Microscopy, NDE/NDT, Neurology, Oncology, Ophthalmology, Other Non-Medical, Otolaryngology, Pulmonology, Urology
    2. Business News:

      Acquisition, Clinical Trials, Funding, Other Business News, Partnership, Patents
    3. Technology:

      Broadband Sources, Doppler, Probes, Tunable Sources
    4. Miscellaneous:

      Jobs & Studentships, Student Theses, Textbooks
  2. Popular Articles

  3. Organizations in the News

    1. (1 articles) UCLA
    2. (1 articles) University of Minnesota
    3. (1 articles) Harvard University
    4. (1 articles) Brigham and Women’s Hospital
    5. (1 articles) Tokyo Medical & Dental University
    6. (1 articles) National Center for Geriatrics and Gerontology in Japan
  4. People in the News

    1. (1 articles) Daniel S. Fried
    2. (1 articles) Yasushi Shimada
    3. (1 articles) Alireza Sadr
    4. (1 articles) Yasunori Sumi
    5. (1 articles) Junji Tagami
    6. (1 articles) Mark E. Brezinski