1. Articles from Alireza Sadr

    1-24 of 53 1 2 3 »
    1. 3D imaging of proximal caries in posterior teeth using optical coherence tomography

      3D imaging of proximal caries in posterior teeth using optical coherence tomography

      Optical coherence tomography (OCT) can create cross-sectional images of tooth without X-ray exposure. This study aimed to investigate the diagnostic accuracy of 3D imaging of OCT for proximal caries in posterior teeth. Thirty-six human molar teeth with 51 proximal surfaces visibly 6 intact, 16 slightly demineralized, and 29 distinct carious changes were mounted to take digital radiographs and 3D OCT images. The sensitivity, specificity and area under the receiver operating characteristic curve (AUC) for the diagnosis of enamel caries and dentin caries were calculated to quantify the diagnostic ability of 3D OCT in comparison with digital radiography. Diagnostic accuracy was ...

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    2. Effect of Pretreatment and Activation Mode on the Interfacial Adaptation of Nanoceramic Resin Inlay and Self-adhesive Resin Cementv

      Effect of Pretreatment and Activation Mode on the Interfacial Adaptation of Nanoceramic Resin Inlay and Self-adhesive Resin Cementv

      Objectives The first objective of this study was to determine if the luting material used for resin nanoceramic inlay affects interfacial adaptation. The second was to investigate whether pretreatment and the adhesive curing method before cementation affects interfacial adaptation. The final objective was to compare activation modes of luting material. Methods Class I cavities were prepared on extracted human third molars. Resin nanoceramic inlays were fabricated using Lava Ultimate CAD/CAM block (3 M). For the control groups, inlays were cemented using Panavia V5 (Kuraray Noritake). For the experimental groups, teeth were randomly divided into five experimental groups with four ...

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    3. Diagnosis of Occlusal Caries with Dynamic Slicing of 3D Optical Coherence Tomography Images

      Diagnosis of Occlusal Caries with Dynamic Slicing of 3D Optical Coherence Tomography Images

      Detecting the extent of occlusal caries is a clinically important but challenging task required for treatment decision making. The aim of this study was to assess the diagnostic power of 3D swept-source optical coherence tomography (OCT) for evaluation of occlusal caries in comparison with X-ray radiography. Extracted human molars not exhibiting American Dental Association (ADA) criteria advanced caries were mounted in a silicone block and digital dental radiographs were captured from the buccal side. Subsequently, occlusal surfaces were scanned with a prototype Yoshida Dental OCT. Thirteen examiners evaluated the presence and extent of caries on radiographs and dynamically sliced 3D ...

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    4. Does lining class-II cavities with flowable composite improve the interfacial adaptation?

      Does lining class-II cavities with flowable composite improve the interfacial adaptation?

      The objective of this study was to assess in-vitro interfacial cavity adaptation of different adhesive/composites systems in class-II restoration using SS-OCT and to confirm the findings with a confocal laser scanning microscope (CLSM). Standardized rectangular-shaped class-II cavities were prepared on 24 extracted human molar teeth, bonded with adhesive and lined with flowable composite. Cavities were further restored by bulk filling using packable composite. Specimens were divided into four groups ( n  = 7) according to restorative materials used; PrimeFil with Estelite Posterior composites (PF; Tokuyama Dental), Clearfil Tri-S Bond Plus with Majesty LV flowable and Majesty Posterior composites (TS; Kuraray Noritake ...

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    5. Detection of Simulated Periradicular Lesions in Porcine Bone by Optical Coherence Tomography

      Detection of Simulated Periradicular Lesions in Porcine Bone by Optical Coherence Tomography

      Introduction The accurate detection of periradicular lesions located under a nonperforated cortical plate poses a challenge in endodontic microsurgery. Optical coherence tomography (OCT) is a noninvasive imaging method that has been successfully used in many dental applications. In this study, we investigated if spectral-domain OCT (SD-OCT) could be used to determine simulated periradicular lesions. Methods Twenty-eight cavities with different depths were prepared on bone plates obtained from 5 porcine mandibles. Both 3-dimensional SD-OCT imaging and micro–computed tomographic (micro-CT) imaging were used to image the bottom of the air-filled cavity and the cavity filled with soft tissue for comparison. The ...

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    6. Three-dimensional assessment of proximal contact enamel using optical coherence tomography

      Three-dimensional assessment of proximal contact enamel using optical coherence tomography

      Objective The purpose of this study was to detect and investigate the association of enamel microcracks with demineralization at proximal contact areas of premolars, using 3D swept-source optical coherence tomography (SS-OCT). Methods Extracted maxillary and mandibular premolars (n = 50 each), without any visible tooth cracks, were examined for demineralization of interproximal contact areas, using the International Caries Detection and Assessment System (ICDAS). SS-OCT was used to evaluate demineralization and detect microcracks. Demineralization progression was divided into 4 types by depth: 0 for sound enamel and Type I, II, and III for enamel demineralization penetrating into the outer third, the middle ...

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    7. A non‐invasive imaging and measurement using optical coherence tomography angiography for the assessment of gingiva: An in vivo study

      A non‐invasive imaging and measurement using optical coherence tomography angiography for the assessment of gingiva: An in vivo study

      Gingiva is the soft tissue that surrounds and protects the teeth. Healthy gingiva provides an effective barrier to periodontal insults to deeper tissue, thus is an important indicator to a patient’s periodontal health. Current methods in assessing gingival tissue health, including visual observation and physical examination with probing on the gingiva, are qualitative and subjective. They may become cumbersome when more complex cases are involved, such as variations in gingival biotypes where feature and thickness of the gingiva are considered. A non‐invasive imaging technique providing depth‐resolved structural and vascular information is necessary for an improved assessment of ...

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    8. 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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    9. Assessment of enamel cracks at adhesive cavosurface margin using three-dimensional swept-source optical coherence tomography

      Assessment of enamel cracks at adhesive cavosurface margin using three-dimensional swept-source optical coherence tomography

      Objectives Swept-source optical coherence tomography (SS-OCT) can construct cross-sectional images of internal biological structures. The aim of this study was to evaluate enamel cracks at the cavosurface margin of composite restorations using SS-OCT. Methods Bowl-shaped cavities were prepared at two locations (mid-coronal and cervical regions) on the enamel surface of 60 bovine teeth. Half of the cavities (30) were treated with phosphoric acid gel. A two-step self-etch adhesive (Clearfil SE Bond) was applied to all cavities and a flowable composite was placed in bulk. After 7 days in water at 37 °C, three-dimensional (3D) images of the specimens were obtained ...

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    10. Optical analysis of enamel and dentin caries in relation to mineral density using swept-source optical coherence tomography

      Optical analysis of enamel and dentin caries in relation to mineral density using swept-source optical coherence tomography

      The aim of this study was to evaluate the signal intensity and signal attenuation of swept source optical coherence tomography (SS-OCT) for dental caries in relation to the variation of mineral density. SS-OCT observation was performed on the enamel and dentin artificial demineralization and on natural caries. The artificial caries model on enamel and dentin surfaces was created using Streptococcus mutans biofilms incubated in an oral biofilm reactor. The lesions were centrally cross sectioned and SS-OCT scans were obtained in two directions to construct a three-dimensional data set, from the lesion surface (sagittal scan) and parallel to the lesion surface ...

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    11. Assessment of bacterial demineralization around composite restorations using swept-source optical coherence tomography (SS-OCT)

      Assessment of bacterial demineralization around composite restorations using swept-source optical coherence tomography (SS-OCT)

      Objective To observe the bacterial demineralization of the enamel and dentin around composite restorations bonded with one-step and two-step self-etch adhesive systems using swept-source optical coherence tomography (SS-OCT). Methods Forty class V cavities (2.5-mm surface diameter, 2.0-mm maximum depth) were prepared on cervical areas of 20 human molars. The specimens were either treated with one-step adhesive (Clearfil Tri-S Bond ND Quick; TS) or two-step adhesive (Clearfil SE Bond; SE), restored with a flowable resin composite (Estelite Flow Quick). Specimens in the demineralized group were incubated for 2 weeks after Streptococcus mutans biofilm formation, while specimens in the control ...

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    12. Monitoring of cariogenic demineralization at the enamel–composite interface using swept-source optical coherence tomography

      Monitoring of cariogenic demineralization at the enamel–composite interface using swept-source optical coherence tomography

      Objectives The aim of this study was to evaluate enamel demineralization at composite restoration margins caused by cariogenic biofilm using swept-source optical coherence tomography (SS-OCT). Methods Sixty round-shaped cavities were prepared on the mid-buccal enamel surface of extracted human molars. The cavities were restored with Estelite Flow Quick flowable composite using either Clearfil SE Bond or Clearfil Tri-S Bond ND bonding agents. Streptococcus mutans suspension was applied to form a cariogenic biofilm on the surface. After 1, 2, or 3 weeks of incubation ( n = 10), the biofilm was removed to observe the carious demineralization at the cavosurface margins using SS-OCT ...

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    13. Internal adaptation of resin composites at two configurations: Influence of polymerization shrinkage and stress

      Internal adaptation of resin composites at two configurations: Influence of polymerization shrinkage and stress

      Objective This study compared internal adaptation of composites under different C-factors and examined the relationship between internal adaptation and polymerization shrinkage parameters. Methods Cylindrical cavities 3 mm in diameter were prepared in 100 human third molars in two depths: 4 mm high C-factor (H-CF) or 1 mm low C-factor (L-CF). After adhesive application (Clearfil SE One, Kuraray Noritake), the composite was placed in two increments in three subgroups: Filtek Supreme (FS, 3 M ESPE); Charisma Diamond (CD, Heraeus Kulzer); Amelogen Plus (AP, Ultradent); and as a single increment in two subgroups: Tetric EvoCeram Bulk Fill (TB, Ivoclar Vivadent) and Venus ...

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    14. The role of enamel thickness and refractive index on human tooth colour

      The role of enamel thickness and refractive index on human tooth colour

      Objectives To investigate the role of enamel thickness and refractive index ( n ) on tooth colour. Methods The colour and enamel thickness of fifteen extracted human central incisors were determined according to CIELab colour scale using spectrophotometer (Crystaleye) and swept-source optical coherence tomography (SS-OCT), respectively. Subsequently, labial enamel was trimmed by approximately 100 μm, and the colour and remaining enamel thickness were investigated again. This cycle was repeated until dentin appeared. Enamel blocks were prepared from the same teeth and their n were obtained using SS-OCT. Multiple regression analysis was performed to reveal any effects of enamel thickness and n on ...

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    15. Assessment of occlusal fissure depth and sealant penetration using optical coherence tomography

      Assessment of occlusal fissure depth and sealant penetration using optical coherence tomography

      Swept source optical coherence tomography (SS-OCT) is an interferometric imaging technique. This study aimed to assess SS-OCT as a diagnostic tool for the evaluation of occlusal fissure depth and sealant penetration into fissure. Seventy investigation sites of occlusal fissures without visible evidence of caries were categorized into four groups (smooth, shallow, intermediate, and deep fissures). Categorization utilized two methods: 1) visually, using a computer screen, and 2) using SS-OCT images. After sealant placement, penetration was observed in SS-OCT. The results obtained from SS-OCT and visual inspections were compared with those of confocal laser scanning microscope (CLSM). The diagnostic power of ...

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    16. Fractography of interface after microtensile bond strength test using swept-source optical coherence tomography

      Fractography of interface after microtensile bond strength test using swept-source optical coherence tomography

      Objective To determine the effect of crosshead speed and placement technique on interfacial crack formation in microtensile bond strength (MTBS) test using swept-source optical coherence tomography (SS-OCT). Materials and methods MTBS test beams (0.9 × 0.9 mm 2 ) were prepared from flat human dentin disks bonded with self-etch adhesive (Clearfil SE Bond, Kuraray) and universal composite (Clearfil AP-X, Kuraray) with or without flowable composite lining (Estelite Flow Quick, Tokuyama). Each beam was scanned under SS-OCT (Santec, Japan) at 1319 nm center wavelength before MTBS test was performed at crosshead speed of either 1 or 10 mm/min ( n = 10 ...

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    17. Assessment of cervical demineralization induced by Streptococcus mutans using swept-source optical coherence tomography

      Assessment of cervical demineralization induced by Streptococcus mutans using swept-source optical coherence tomography

      Exposed root surfaces due to gingival recession are subject to biofilm stagnation that can result in caries formation. Cervical enamel and dentin demineralization induced by a cariogenic biofilm was evaluated using swept-source optical coherence tomography (SS-OCT). The cementoenamel junction (CEJ) sections of extracted human teeth were subjected to demineralization for 1, 2, or 3 weeks. A suspension of Streptococcus mutans was applied to form a cariogenic biofilm using an oral biofilm reactor. After incubation, demineralization was observed by SS-OCT. For the analysis of SS-OCT signal, the value of the area under the curve (AUC) of the signal profile was measured ...

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    18. Assessment of Self-Adhesive Resin Composites: Nondestructive Imaging of Resin–Dentin Interfacial Adaptation and Shear Bond Strength

      Assessment of Self-Adhesive Resin Composites: Nondestructive Imaging of Resin–Dentin Interfacial Adaptation and Shear Bond Strength

      Shear bond strength (SBS) and the interfacial adaptation (IA) of self-adhesive resin (SAR) composites to dentin were evaluated. Two SARs [Vertise Flow (VTF) and Fusio Liquid Dentin (FLD)] were evaluated and compared with a conventional restorative system [adhesive: OptiBond FL and composite: Herculite Précis (OBF/HP)]. Human third molars were used for SBS testing and IA imaging (n=7) using optical coherence tomography (OCT). Flattened dentin disks were prepared and the composites were applied into molds (2.4 mm diameter) that were positioned on dentin. Samples were subjected to SBS testing and OCT analysis, which considered an increase in ...

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    19. Non-destructive evaluation of an internal adaptation of resin composite restoration with swept-source optical coherence tomography and micro-CT

      Non-destructive evaluation of an internal adaptation of resin composite restoration with swept-source optical coherence tomography and micro-CT

      Swept-source optical coherence tomography (SS-OCT) and micro-CT can be useful non-destructive methods for evaluating internal adaptation. There is no comparative study evaluating the two methods in the assessment of internal adaptation in composite restoration. The purpose of this study was to compare internal adaptation measurements of SS-OCT and micro-CT. Two cylindrical cavities were created on the labial surface of twelve bovine incisors. The 24 cavities were randomly assigned to four groups of dentin adhesives: (1) three-step etch-and-rinse adhesive, (2) two-step etch-and-rinse adhesive, (3) two-step self-etch adhesive, and (4) one-step self-etch adhesive. After application, the cavities were filled with resin composite ...

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    20. Assessment of current adhesives in class I cavity: Nondestructive imaging using optical coherence tomography and microtensile bond strength

      Assessment of current adhesives in class I cavity: Nondestructive imaging using optical coherence tomography and microtensile bond strength

      Objectives To evaluate the sealing ability and the microtensile bond strength (MTBS) of different adhesive systems bonded to dentin in class I cavities. Methods Round tapered dentin cavities (3-mm diameter, 1.5-mm height) prepared in extracted human molars were restored using composite resin (Clearfil Majesty Posterior) with two-step etch-and-rinse adhesive system (Adper Single Bond 2: ASB2), two-step self-etch adhesive (Clearfil SE Bond: CSEB), all-in-one adhesives (G-Bond Plus: GBP; Tri-S Bond Plus: TSBP), or no adhesive (Control), or bonded using low-shrinkage composite with its proper adhesive (Filtek Silorane, Silorane Adhesive System: FSS). After 24-h water storage or 10,000 cycles of ...

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    21. Interfacial Adaptation of Composite Restorations Before and After Light Curing: Effects of Adhesive and Filling Technique

      Interfacial Adaptation of Composite Restorations Before and After Light Curing: Effects of Adhesive and Filling Technique

      Purpose: To investigate the effects of placement technique and adhesive material on adaptation of composites before and after light curing. Materials and Methods: Cylindrical cavities (3 mm diameter, 1.7 mm depth) in extracted human molars were restored in 6 groups (n = 5) using 2 adhesives - two-step self-etching Clearfil SE Bond 2 (SE2) and all-in-one Clearfil Tri-S Bond Plus (TSP) (Kuraray Noritake Dental) - and 2 composites - Estelite Sigma Quick (ESQ) and Estelite Flow Quick (FLQ) (Tokuyama Dental) - placed with three different techniques: ESQ bulk placed, FLQ lining followed by ESQ and FLQ bulk placed. Specimens were scanned twice using swept-source ...

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    22. Observation of white spot lesions using swept source optical coherence tomography (SS-OCT): in vitro and in vivo study

      Observation of white spot lesions using swept source optical coherence tomography (SS-OCT): in vitro and in vivo study

      This study aimed to assess swept source optical coherence tomography (SS-OCT) for in vitro and in vivo detection of enamel white spot lesion (WSL). WSLs without surface breakdown on 33 extracted human posterior teeth were non-invasively scanned using SSOCT. The teeth were then cross-sectioned and imaged under confocal laser scanning microscope (CLSM) and light microscopy (LM). SS-OCT cross-sectional images were compared with CLSM and LM. WSL shapes in SS-OCT images closely corresponded to those of LM. There were significant correlations ( p <0.001) in WSLs depth between SS-OCT and LM (r=0.92), SS-OCT and CLSM (r=0.80) and ...

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    23. Assessment of current adhesives in class I cavity: Nondestructive imaging using optical coherence tomography and microtensile bond strength

      Assessment of current adhesives in class I cavity: Nondestructive imaging using optical coherence tomography and microtensile bond strength

      Objectives To evaluate the sealing ability and the microtensile bond strength (MTBS) of different adhesive systems bonded to dentin in class I cavities. Methods Round tapered dentin cavities (3-mm diameter, 1.5-mm height) prepared in extracted human molars were restored using composite resin (Clearfil Majesty Posterior) with two-step etch-and-rinse adhesive system (Adper Single Bond 2: ASB2), two-step self-etch adhesive (Clearfil SE Bond: CSEB), all-in-one adhesives (G-Bond Plus: GBP; Tri-S Bond Plus: TSBP), or no adhesive (Control), or bonded using low-shrinkage composite with its proper adhesive (Filtek Silorane, Silorane Adhesive System: FSS). After 24-h water storage or 10,000 cycles of ...

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    24. Validation of Optical Coherence Tomography against Micro-computed Tomography for Evaluation of Remaining Coronal Dentin Thickness

      Validation of Optical Coherence Tomography against Micro-computed Tomography for Evaluation of Remaining Coronal Dentin Thickness

      Introduction Optical coherence tomography (OCT) is a noninvasive modality to obtain in-depth images of biological structures. A dental OCT system has become available for chairside application. This in vitro study hypothesized that swept-source OCT can be used to measure the remaining dentin thickness (RDT) at the roof of the dental pulp chamber during excavation of deep caries. Methods Human molar teeth with deep occlusal caries were investigated. After obtaining 2-dimensional and 3-dimensional OCT scans using a swept-source OCT system at a 1330-nm center wavelength, RDT was evaluated by image analysis software. Microfocus x-ray computed tomographic (micro-CT) images were obtained from ...

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    1. (52 articles) Alireza Sadr
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    Real-time Tomographic Monitoring of Composite Restoration Placement Using SS-OCT Validation of swept-source optical coherence tomography (SS-OCT) for the diagnosis of occlusal caries Non-destructive 3D imaging of composite restorations using optical coherence tomography: marginal adaptation of self-etch adhesives Non-invasive quantification of resin–dentin interfacial gaps using optical coherence tomography: Validation against confocal microscopy Estimation of lesion progress in artificial root caries by swept source optical coherence tomography in comparison to transverse microradiography Longitudinal assessment of subsurface artificial root caries lesions by optical coherence tomography in comparison with transverse microradiography Relationship between refractive index and mineral content of enamel and dentin using SS-OCT and TMR Effect of hydration on assessment of early enamel lesion using swept-source optical coherence tomography 3D evaluation of composite resin restoration at practical training using swept-source optical coherence tomography (SS-OCT) Symposium on Dental OCT June 20th 2013 in Tokyo, Japan. Long-Term Arterial Remodeling After Bioresorbable Scaffold Implantation 4-Year Follow-up of Quantitative Coronary Angiography, Histology and Optical Coherence Tomography Visualization of Bacterial Colonization and Cellular Layers in a Gut-on-a-Chip System Using Optical Coherence Tomography