1. Articles in category: Dentistry

    1-24 of 464 1 2 3 4 ... 18 19 20 »
    1. Wide field of view optical coherence tomography for structural and functional diagnoses in dentistry

      Wide field of view optical coherence tomography for structural and functional diagnoses in dentistry

      We report herein the fabrication and performance response of a three-dimensional (3-D) intraoral scan probe based on optical coherence tomography (OCT) that enables 3-D structural and functional diagnoses of the human teeth. The OCT system was configured using a swept-source OCT (SS-OCT) with a center wavelength of 1310 nm. The scan probe was built using an MEMS mirror and an optical collimator. The implemented SS-OCT equipped with the MEMS-based scan probe yielded an axial resolution of 10  μm and a scan range of 8  ×  8  mm 2 . Two-dimensional (2-D) cross-sectional images of the teeth were acquired by the scan probe ...

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      Mentions: Jonghyun Eom
    2. Effect of a coating material containing surface reaction-type pre-reacted glass-ionomer filler on prevention of primary enamel demineralization detected by optical coherence tomography

      Effect of a coating material containing surface reaction-type pre-reacted glass-ionomer filler on prevention of primary enamel demineralization detected by optical coherence tomography

      We used optical coherence tomography to examine the effect of a coating material containing surface reaction-type pre-reacted glass-ionomer (S-PRG) filler on primary enamel demineralization in 18 extracted human primary teeth. The pulp was removed, and each tooth was ultrasonically cleaned with distilled water. Six teeth were treated with 0.1-M lactic acid buffer solution (De group). In the second group (n = 6), a thin film of coating material was applied before demineralization (PRG group). A third group (Control group; n = 6) was maintained in artificial saliva. Using optical coherence tomography, we measured peak signal intensity (dB) and width at 1 ...

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    3. Assessment of root caries under wet and dry conditions using swept-source optical coherence tomography (SS-OCT)

      Assessment of root caries under wet and dry conditions using swept-source optical coherence tomography (SS-OCT)

      The purpose of this study was to compare optical properties of root caries under two observing conditions using swept-source optical coherence tomography (SS-OCT). In vitro and natural root caries were observed by SS-OCT under wet and dry conditions, followed by confocal laser scanning microscope (CLSM) and transverse microradiography (TMR). Signal intensity (SI), distance between SI peaks (SI-distance) and optical lesion depth were obtained from OCT. Lesion depth was measured from CLSM; lesion depth (LD TMR ) and mineral loss (ML) were obtained from TMR. In vitro root caries under wet and dry conditions showed different OCT images and SI patterns. Lesion ...

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    4. Optical Evaluation of Enamel Microleakage with One-Step Self-Etch Adhesives

      Optical Evaluation of Enamel Microleakage with One-Step Self-Etch Adhesives

      Objective: In this in vitro study, cross-polarization optical coherence tomography (CP-OCT) was used to evaluate microleakage in dental composite restorations bonded to enamel with two types of one-step self-etching (SE) adhesives. Background data: One-step SE adhesives were proposed to simplify bonding of composite restorations. However, bonding of these simplified adhesive to dental enamel is still questionable. OCT is a promising diagnostic tool that allows micron-scale imaging of biological tissues and structures. Methods: Class-V cavities (4-mm diameter × 1-mm depth) were prepared on the labial surfaces of extracted human anterior teeth with margins and floor located in enamel. The cavities were then ...

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      Mentions: Turki Bakhsh
    5. Optical Quantification of Microgaps at Dentin-Composite Interface

      Optical Quantification of Microgaps at Dentin-Composite Interface

      Objective . Microgap formation between polymer-based resin system and teeth surfaces is undetectable by conventional x-rays. Therefore, this in vitro study was designed to assess the adaptation of polymeric dental fillings and microgap formation at the tooth floor using cross-polymerization optical coherence tomography (CP-OCT). Materials and Methods . Class-I cavities (4 mm diameter × 1.5 mm depth) were prepared in twenty extracted molar teeth and divided into two groups: ESQ and DI (n = 10). All groups were bonded with Tetric-N Bond universal (Ivoclar/Vivadent) in selective etching mode. Then, each group was restored with either Estelite ∑ Quick dental composite (ESQ; Tokuyama Dental ...

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      Mentions: Turki Bakhsh
    6. OCT for early quality evaluation of tooth–composite bond in clinical trials

      OCT for early quality evaluation of tooth–composite bond in clinical trials

      Objectives To evaluate early quality of composite restorations with a universal adhesive in different application modes clinically and with optical coherence tomography (OCT). Methods 22 patients with four non-carious cervical lesions each received composite restorations (Filtek Supreme TM XTE, 3 M). The universal adhesive Scotchbond Universal TM (SBU, 3 M) was applied with three etching protocols: self-etch (SE), selective-enamel-etch (SEE) and etch-and-rinse (ER). The etch-and-rinse adhesive OptiBond TM FL (OFL, Kerr) served as a control. Restorations were imaged by OCT (Thorlabs) directly after application (t 0 ). After 14 days (t 1 ) and 6 month (t 2 ) OCT imaging (interfacial adhesive ...

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    7. Use of Optical Clearing Agents for Imaging Root Surfaces With Optical Coherence Tomography

      Use of Optical Clearing Agents for Imaging Root Surfaces With Optical Coherence Tomography

      The diagnosis of root caries and root fractures is of increasing importance due to our aging population. The objective of this study is to show that optical clearing agents can be used to increase the visibility of subsurface structures in tooth roots to aid in the diagnosis of root caries depth and extension and to differentiate from subsurface defects. Previous studies have shown that high refractive index fluids can increase the depth penetration of optical coherence tomography (OCT) for imaging caries lesions on tooth enamel. Extracted teeth with suspected root caries were imaged with (OCT) with and without the addition ...

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    8. In vitro and clinical evaluation of optical coherence tomography for the detection of subgingival calculus and root cementum

      In vitro and clinical evaluation of optical coherence tomography for the detection of subgingival calculus and root cementum

      This study evaluated the effectiveness of swept-source optical coherence tomography (ss-OCT) for detecting calculus and root cementum during periodontal therapy. Optical coherence tomography (OCT) images were taken before and after removal of subgingival calculus from extracted teeth and compared with non-decalcified histological sections. Porcine gingival sheets of various thicknesses were applied to the root surfaces of extracted teeth with calculus and OCT images were taken. OCT images were also taken before and after scaling and root planing (SRP) in human patients. In vitro , calculus was clearly detected as a white-gray amorphous structure on the root surface, which disappeared after removal ...

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    9. Quantitative measurement of peri-implant bone defects using optical coherence tomography

      Quantitative measurement of peri-implant bone defects using optical coherence tomography

      Purpose The purpose of this study was to visualize and identify peri-implant bone defects in optical coherence tomography (OCT) images and to obtain quantitative measurements of the defect depth. Methods Dehiscence defects were intentionally formed in porcine mandibles and implants were simultaneously placed without flap elevation. Only the threads of the fixture could be seen at the bone defect site in the OCT images, so the depth of the peri-implant bone defect could be measured through the length of the visible threads. To analyze the reliability of the OCT measurements, the flaps were elevated and the depth of the dehiscence ...

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    10. Optical coherence tomography to evaluate variance in the extent of carious lesions in depth

      Optical coherence tomography to evaluate variance in the extent of carious lesions in depth

      Evaluation of variance in the extent of carious lesions in depth at smooth surfaces within the same ICDAS code group using optical coherence tomography (OCT) in vitro and in vivo. (1) Verification/validation of OCT to assess non-cavitated caries: 13 human molars with ICDAS code 2 at smooth surfaces were imaged using OCT and light microscopy. Regions of interest (ROI) were categorized according to the depth of carious lesions. Agreement between histology and OCT was determined by unweighted Cohen’s Kappa and Wilcoxon test. (2) Assessment of 133 smooth surfaces using ICDAS and OCT in vitro, 49 surfaces in vivo ...

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    11. Evaluation of marginal gap of lithium disilicate glass ceramic crowns with optical coherence tomography

      Evaluation of marginal gap of lithium disilicate glass ceramic crowns with optical coherence tomography

      arginal gap (MG) was the most important factor to evaluate the success of crowns. The study was to assess the MG of lithium disilicate glass ceramic crowns with spectral domain optical coherence tomography (OCT) and stereomicroscopy in vitro , and to provide evidence to measure the MG with OCT. Consistency was observed between OCT and stereomicroscopy to measure the MG after cementation. There was no significant difference between the MG of lithium disilicate glass ceramic crowns using OCT and stereomicroscopy (OCT 59.55  ±  7.22   μ m, stereomicroscope 59.48  ±  6.53   μ m, P   =  0.736) after cementation. OCT was a noninvasive ...

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    12. Evaluation of the polymerization shrinkage of experimental flowable composite resins through optical coherence tomography

      Evaluation of the polymerization shrinkage of experimental flowable composite resins through optical coherence tomography

      This study evaluated the polymerization shrinkage of two experimental flowable composite resins (CR) with different proportions of Urethane dimethacrylate (UDMA)/triethylene glycol dimethacrylate (TEGDMA) monomers in the organic matrix (50:50 and 60:40, respectively). A commercially available flowable CR, Tetric N-Flow (Ivoclair Vivadent, Liechtenstein, Germany), was employed as the control group. The resins were inserted in a cylindrical teflon mold (7 mm diameter, 0.6 mm height) and scanned with OCT before photoactivation, immediately after and 15 minutes after light-curing (Radii-Cal, SDI, Australia, 1,200 mW/cm 2 ) exposure. A Callisto SD-OCT system (Thorlabs Inc, USA), operating at 930 ...

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    13. Silver nanoparticles as optical clearing agent enhancers to improve caries diagnostic by optical coherence tomography

      Silver nanoparticles as optical clearing agent enhancers to improve caries diagnostic by optical coherence tomography

      The use of silver nanoparticles as optical clearing agent (OCA) enhancers to improve caries diagnostic by optical coherence tomography (OCT) is demonstrated here. Five molars with no evident cavitation were selected. The OCAs were based on aqueous solution of silver nanoparticles (AgNP, 1.18x 10 14 particles/mL, ø ≈ 10nm) and its dilution at 10% in glycerol. Teeth were placed on a platform with a micrometric screw, and after applying the OCAs, they were scanned with a Callisto SD-OCT system operating ate 930nm central wavelength. The occlusal surfaces were scanned by OCT, capturing crosssectional images with 8 mm transversal scanning, generating ...

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    14. Effect of bioglass on artificially induced enamel lesion around orthodontic brackets: OCT study

      Effect of bioglass on artificially induced enamel lesion around orthodontic brackets: OCT study

      Background and Objective: White spot lesions (WSLs) are commonly seen after completing orthodontic treatment. Different approaches have been suggested to avoid such a complication. Recently, 45S5 bioglass (BG) was introduced as remineralizing agent. Therefore, the objective of this in-vitro study was to assess the effect of BG in remineralizing WSLs using Optical coherence tomography (OCT). Methods: Fifteen human premolar teeth were sectioned and bonded to orthodontic brackets with Transbond XT primer followed by Transbond PLUS color change adhesive (3M Unitek, USA) on their smooth surfaces according to the manufacturer’s instructions. Then, all specimens were varnished excluding the area of ...

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      Mentions: Turki Bakhsh
    15. Lesion dehydration rate changes with the surface layer thickness during enamel remineralization

      Lesion dehydration rate changes with the surface layer thickness during enamel remineralization

      A transparent highly mineralized outer surface zone is formed on caries lesions during remineralization that reduces the permeability to water and plaque generated acids. However, it has not been established how thick the surface zone should be to inhibit the penetration of these fluids. Near-IR (NIR) reflectance coupled with dehydration can be used to measure changes in the fluid permeability of lesions in enamel and dentin. Based on our previous studies, we postulate that there is a strong correlation between the surface layer thickness and the rate of dehydration. In this study, the rates of dehydration for simulated lesions in ...

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    16. Deep learning classifier with optical coherence tomography images for early dental caries detection

      Deep learning classifier with optical coherence tomography images for early dental caries detection

      Dental caries is a microbial disease that results in localized dissolution of the mineral content of dental tissue. Despite considerable decline in the incidence of dental caries, it remains a major health problem in many societies. Early detection of incipient lesions at initial stages of demineralization can result in the implementation of non-surgical preventive approaches to reverse the demineralization process. In this paper, we present a novel approach combining deep convolutional neural networks (CNN) and optical coherence tomography (OCT) imaging modality for classification of human oral tissues to detect early dental caries. OCT images of oral tissues with various densities ...

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    17. Influence of the Loci of Non-Cavitated Fissure Caries on Its Detection with Optical Coherence Tomography

      Influence of the Loci of Non-Cavitated Fissure Caries on Its Detection with Optical Coherence Tomography

      Objective The main objective of this study was to evaluate the accuracy of optical coherence tomography (OCT) in detecting naturally occurring non-cavitated fissure caries (NCFC) in totality and at different loci by visually assessing cross-sectional OCT scans (B-scan) with an interpretation criterion. The secondary objective was to evaluate the agreement between dimensions of NCFC measured with OCT and polarized light microscopy (PLM). Methods 71 investigation sites of sound fissure and naturally occurring NCFC on human extracted premolars were identified and scanned with a swept-source OCT. The teeth were then sectioned bucco-lingually at the investigation sites and imaged using PLM. Two ...

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    18. Evaluation of adaptation of ceramic inlays using optical coherence tomography and replica technique

      Evaluation of adaptation of ceramic inlays using optical coherence tomography and replica technique

      Optical coherence tomography (OCT) has generally been used as a nondestructive technique to evaluate integrities of composite restorations. We investigated marginal and internal adaptations of ceramic inlay restorations with OCT and compared them to results with the silicone replica technique. Round-shaped class I cavities were prepared on 16 human maxillary first premolar teeth. Ceramic inlays were fabricated. Silicone replicas from inlays were obtained and sectioned to measure marginal and internal adaptations with a stereomicroscope (Leica Dfc 295, Bensheim, Germany). Inlays were cemented on respective teeth. Marginal and internal adaptations were then measured with the OCT system (Thorlabs, New Jersey, USA ...

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      Mentions: Thorlabs Leica
    19. Detection of carious lesions utilizing depolarization imaging by polarization sensitive optical coherence tomography

      Detection of carious lesions utilizing depolarization imaging by polarization sensitive optical coherence tomography

      As dental caries is one of the most common diseases, the early and noninvasive detection of carious lesions plays an important role in public health care. Optical coherence tomography (OCT) with its ability of depth-resolved, high-resolution, noninvasive, fast imaging has been previously recognized as a promising tool in dentistry. Additionally, polarization sensitive imaging provides quantitative measures on the birefringent tissue properties and can be utilized for imaging dental tissue, especially enamel and dentin. By imaging three exemplary tooth samples ex vivo with proximal white spot, brown spot, and cavity, we show that the combination of polarization sensitive OCT and the ...

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    20. Comparison of microtomography and optical coherence tomography on apical endodontic filling analysis

      Comparison of microtomography and optical coherence tomography on apical endodontic filling analysis

      OBJECTIVES: To compare in vitro differences in the apical filling regarding working length (WL) change and presence of voids and to validate OCT in comparison to µCT for the detection of failures in the apical filling. METHODS: Forty-five uniradicular teeth with round canals, divided into groups (n=15) following the obturation protocols: CL (Lateral condensation), TMC (thermomechanical compaction) and SC (single cone). Samples were scanned using µCT (parameters: 80 kV, 222 µA, and resolution of 11µm), OCT (parameters: SSOCT, 1300nm and axial resolution of 12µm), and periapical digital radiography. The images were analyzed by two blind and calibrated ...

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    21. Resin infiltration analysis into carious lesions by optical coherence tomography

      Resin infiltration analysis into carious lesions by optical coherence tomography

      Purpose/aim: The minimally invasive approach claims for the detection and treatment of early caries lesions. Resin infiltrant materials can penetrate into porosities of the lesion body by capillary forces, preventing the progression of white spot lesions, improving esthetic and providing support to enamel. It is suggested that optical coherence tomography (OCT) could assess penetration depth of the resin infiltrant into white spots lesions, which may provide information about the lesion's progression.

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    22. Feature of the Week 08/17/2017: In Vivo Assessment of Periodontal Structures and Measurement of Gingival Sulcus with Optical Coherence Tomography: A Pilot Study

      Feature of the Week 08/17/2017: In Vivo Assessment of Periodontal Structures and Measurement of Gingival Sulcus with Optical Coherence Tomography: A Pilot Study

      There has been increasing interest on the development of clinically acceptable, more sensitive and specific methods for non-invasive diagnosis in Periodontics. In this pilot study, the performance of an Optical Coherence Tomography (OCT) system in imaging periodontal structures in humans was evaluated. Gingival sulcus depth measurements were obtained and compared with traditional probes. In total, 445 sites of 23 periodontally healthy individuals were measured by 3 instruments: North Carolina manual probe, Florida automated probe and OCT at 1325 nm. To obtain quantitative measurements from OCT images, the gingival refractive index was also determined. Discomfort/pain perception and the duration of ...

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    1-24 of 464 1 2 3 4 ... 18 19 20 »
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