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  • Environmental SEM and dye penetration observation on resin-tooth interface using different light curing method.
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    Environmental SEM and dye penetration observation on resin-tooth interface using different light curing method.

    Dent Mater J. 2016;35(1):89-96

    Authors: Yoshikawa T, Morigami M, Sadr A, Tagami J

    Abstract
    The aim of this study was the effects of different light curing methods on marginal sealing and resin composite adaptation to the cavity wall using the dye penetration test and environmental scanning electron microscope (SEM) observations. Cylindrical cavities were prepared on cervical regions. The teeth were restored with Clearfil Liner Bond 2 V adhesive and filled with Clearfil Photo Bright or Palfique Estelite resin composites. These resins were cured with a conventional light-curing method or a slow-start curing method. After thermal cycling, the specimens were subjected to the dye penetration test to evaluate marginal sealing and adaptation of the resin composites to the cavity walls. These resin-tooth interfaces were then observed using environmental SEM. The light-cured resin composite, which exhibited increased contrast ratios during polymerization, suggests high compensation for polymerization stress using the slow-start curing method. There was a high correlation between dye penetration test and environmental SEM observation.

    (26830828) – in process]

    Bibliography

  • Environmental SEM and dye penetration observation on resin-tooth interface using different light curing method.
    .

    Environmental SEM and dye penetration observation on resin-tooth interface using different light curing method.

    Dent Mater J. 2016;35(1):89-96

    Authors: Yoshikawa T, Morigami M, Sadr A, Tagami J

    Abstract
    The aim of this study was the effects of different light curing methods on marginal sealing and resin composite adaptation to the cavity wall using the dye penetration test and environmental scanning electron microscope (SEM) observations. Cylindrical cavities were prepared on cervical regions. The teeth were restored with Clearfil Liner Bond 2 V adhesive and filled with Clearfil Photo Bright or Palfique Estelite resin composites. These resins were cured with a conventional light-curing method or a slow-start curing method. After thermal cycling, the specimens were subjected to the dye penetration test to evaluate marginal sealing and adaptation of the resin composites to the cavity walls. These resin-tooth interfaces were then observed using environmental SEM. The light-cured resin composite, which exhibited increased contrast ratios during polymerization, suggests high compensation for polymerization stress using the slow-start curing method. There was a high correlation between dye penetration test and environmental SEM observation.

    (26830828) – in process]

    Bibliography

  • The effects of ethanol on the size-exclusion characteristics of type I dentin collagen to adhesive resin monomers.

    The effects of ethanol on the size-exclusion characteristics of type I dentin collagen to adhesive resin monomers.

    Acta Biomater. 2016 Jan 28;

    Authors: Chiba A, Zhou J, Nakajima M, Tan J, Tagami J, Scheffel D, Hebling J, Agee KA, Breschi L, Grégoire G, Jang SS, Tay FR, Pashley DH

    Abstract
    During dentin bonding with etch-and-rinse adhesive systems, phosphoric acid etching of mineralized dentin solubilizes the mineral crystallites and replaces them with bound and unbound water. During the infiltration phase of dentin bonding, solvated adhesive resin comonomers are supposed to replace all of the unbound collagen water and polymerize into copolymers. A recently published review suggested that dental monomers are too large to enter and displace water from tightly-packed collagen molecules. Conversely, recent work from the authors’ laboratory demonstrated that HEMA and TEGDMA freely equilibrate with water-saturated dentin matrices. However, because adhesive blends are solvated in organic solvents, those solvents may remove enough free water to allow collagen molecules to come close enough to exclude adhesive monomer permeation. The present study analyzed the size-exclusion characteristics of dentin collagen, using a gel permeation-like column chromatography technique, filled with dentin powder instead of Sephadex beads as the stationary phase. The elution volumes of different sized test molecules, including adhesive resin monomers, studied in both water-saturated dentin, and again in ethanol-dehydrated dentin powder, showed that adhesive resin monomers can freely diffuse into both hydrated and dehydrated collagen molecules. Under these in vitro conditions, all free and some of the loosely-bound water seems to have been removed by ethanol. These results validate the concept that adhesive resin monomers can permeate tightly-bound water in ethanol-saturated collagen molecules during infiltration by etch-and-rinse adhesives.
    STATEMENT OF SIGNIFICANCE: It has been reported that collagen molecules in dentin matrices are packed too close together to allow permeation of adhesive monomers between them. Resin infiltration, in this view, would be limited to extrafibrillar spaces. Our work suggests that monomers equilibrate with collagen water in both water and ethanol-saturated dentin matrices.

    (26827779) – as supplied by publisher]

    Bibliography

  • Comparative study of demineralized collagen degradation determined by Hydroxyproline assay and Microscopic depth measurement.
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    Comparative study of demineralized collagen degradation determined by Hydroxyproline assay and Microscopic depth measurement.

    J Dent. 2016 Jan 7;

    Authors: Islam MS, Khunkar SJ, Nakashima S, Sadr A, Nikaido T, Tagami J

    Abstract
    INTRODUCTION: Quantification of collagen degradation is an important parameter to evaluate dentin caries progression or the efficacy of caries prevention aid. The aim of this study was to validate the simple light microscopic technique (LM) to evaluate collagen degradation by comparing with hydroxyproline assay technique (HPN).
    MATERIALS AND METHODS: Bovine root dentin blocks were embedded in acrylic resin, polished and covered with nail varnish except a 1.5×2.5mm window. The specimens were demineralized in acetate buffer (pH4.3) for 3 days to create incipient lesions and were exposed to collagenase enzyme for 6, 9 and 16hours. The specimens were sectioned into thin sections (200-220μm) to measure the degraded depth of collagen matrix by LM. The enzyme solutions were allocated to HPN assay using the simplified chloramines-T method. Correlation between LM and HPN was evaluated by Pearson correlation analysis. Anti-collagen degradation efficacy of 0.12% chlorhexidine (CHX) was evaluated by LM.
    RESULT: The depths of the degraded collagen and amount of hydroxyproline in 3 exposure periods were 27.8±3.8μm and 28.7±4.2μg for 6hours, 48.1±8.6μm and 45.3±6.1μg for 9hours, and 74.2±9.7μm and 71.3±8.0μg for 16hours, respectively. A significantly positive correlation (r=0.94, CI: 0.88∼0.97, p<0.0001) was observed between LM and HPN and incubation time showed a linear correlation with amount of collagen degradation (R2=0.92). The CHX group (28.6±3.3μm) showed significantly lower collagen degradation than that of control group (53.1±7.8μm: p<0.01).
    CONCLUSION: The LM might be a reliable and simplified method to evaluate collagen degradation.

    (26773460) – as supplied by publisher]

    Bibliography

  • Impact of toothpaste on abrasion of sound and eroded enamel: An in vitro white light interferometer study.

    Impact of toothpaste on abrasion of sound and eroded enamel: An in vitro white light interferometer study.

    Am J Dent. 2015 Oct;28(5):268-72

    Authors: Nakamura M, Kitasako Y, Nakashima S, Sadr A, Tagami J

    Abstract
    PURPOSE: To evaluate the influence of brushing using toothpastes marketed under different categories on abrasion of sound and eroded enamel in vitro at nanometer scale using a white light interferometer (WLI).
    METHODS: Enamel surface of resin-embedded bovine incisors were fine polished with diamond slurry and divided into testing area (approximately 2 mm x 4 mm) and reference area using a nail varnish. The enamel specimens were randomly assigned to 10 groups (n = 10 each); six of which were subjected to erosive challenge. The testing area in these eroded groups was exposed to 10 ml of Coca-Cola for 90 seconds and then rinsed for 10 seconds in deionized water (DW). Enamel specimens, except for those in one eroded group, were brushed by an automatic brushing machine with 120 linear motion strokes in 60 seconds under load of 250 g with/without toothpaste slurry. After the toothbrushing abrasion, each specimen was rinsed for 10 seconds with DW followed by immersion in artificial saliva for 2 hours. Toothpaste slurries were prepared containing one of the four toothpastes used and DW in a ratio of 1:2. The erosion-abrasion cycle was repeated three times. Then, the nail varnish was removed and enamel surface loss (SL) was measured by the WLI. Data were statistically analyzed by one-way ANOVA followed by Bonferroni’s correction at significance level of 0.05.
    RESULTS: For eroded specimens, the mean SL values of groups not brushed and brushed with no toothpaste were not significantly different, but were significantly lower than those of whitening, anti-erosion and anti-caries toothpaste groups (P < 0.001). The whitening toothpaste group showed significantly higher SL than all other groups (P < 0.001). For sound enamel specimens, SL was not measured except for the whitening toothpaste group.

    (26714344) – in process]

    Bibliography

  • Influence of resin coating on bond strength of self-adhesive resin cements to dentin.
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    Influence of resin coating on bond strength of self-adhesive resin cements to dentin.

    Dent Mater J. 2015;34(6):822-7

    Authors: Giannini M, Takagaki T, Bacelar-Sá R, Vermelho PM, Ambrosano GM, Sadr A, Nikaido T, Tagami J

    Abstract
    This study evaluated the effect of resin coating (COA) on dentin bond strength (BS) of five resin cements (RC). Ten groups were tested, according to RC and COA combinations. RCs were applied onto prepolymerized resin discs, which were bonded to dentin surfaces. Teeth were stored in water for 24 h, subjected to 5,000 thermocycles and sectioned to obtain beams, which were tested in tension. The COA increased the BS for Panavia F2.0, RelyX Unicem, and RelyX Unicem 2, whereas no changes in BS were observed for two other RCs; Clearfil SA Cement, which showed the lowest BS among groups with COA and G-Cem, which showed the highest BS among RCs without COA. COA can increase the BS of RC depending on the type of RC.

    (26632230) – in process]

    Bibliography

  • Influence of resin coating on bond strength of self-adhesive resin cements to dentin.
    .

    Influence of resin coating on bond strength of self-adhesive resin cements to dentin.

    Dent Mater J. 2015;34(6):822-7

    Authors: Giannini M, Takagaki T, Bacelar-Sá R, Vermelho PM, Ambrosano GM, Sadr A, Nikaido T, Tagami J

    Abstract
    This study evaluated the effect of resin coating (COA) on dentin bond strength (BS) of five resin cements (RC). Ten groups were tested, according to RC and COA combinations. RCs were applied onto prepolymerized resin discs, which were bonded to dentin surfaces. Teeth were stored in water for 24 h, subjected to 5,000 thermocycles and sectioned to obtain beams, which were tested in tension. The COA increased the BS for Panavia F2.0, RelyX Unicem, and RelyX Unicem 2, whereas no changes in BS were observed for two other RCs; Clearfil SA Cement, which showed the lowest BS among groups with COA and G-Cem, which showed the highest BS among RCs without COA. COA can increase the BS of RC depending on the type of RC.

    (26632230) – in process]

    Bibliography

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

    Dent Mater. 2015 Nov 21;

    Authors: Han SH, Sadr A, Tagami J, Park SH

    Abstract
    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. All restorations underwent a thermocycling challenge, and then, eight SS-OCT images were taken using a Santec OCT-2000™ (Santec Co., Komaki, Japan). The internal adaptation was also evaluated using micro-CT (Skyscan, Aartselaar, Belgium). The image analysis was used to calculate the percentage of defective spot (%DS) and compare the results. The groups were compared using one-way ANOVA with Duncan analysis at the 95% significance level. The SS-OCT and micro-CT measurements were compared with a paired t-test, and the relationship was analyzed using a Pearson correlation test at the 95% significance level. The %DS results showed that Group 3≤Group 4<Group 1≤Group 2 on both SS-OCT and micro-CT images. The %DSs on micro-CT were lower than SS-OCT (p<0.05) and the Pearson correlation coefficient between SS-OCT and micro-CT was r=0.787 (p<0.05).

    (26614427) – as supplied by publisher]

    Bibliography

  • 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.

    Dent Mater. 2015 Nov 21;

    Authors: Han SH, Sadr A, Tagami J, Park SH

    Abstract
    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. All restorations underwent a thermocycling challenge, and then, eight SS-OCT images were taken using a Santec OCT-2000™ (Santec Co., Komaki, Japan). The internal adaptation was also evaluated using micro-CT (Skyscan, Aartselaar, Belgium). The image analysis was used to calculate the percentage of defective spot (%DS) and compare the results. The groups were compared using one-way ANOVA with Duncan analysis at the 95% significance level. The SS-OCT and micro-CT measurements were compared with a paired t-test, and the relationship was analyzed using a Pearson correlation test at the 95% significance level. The %DS results showed that Group 3≤Group 4<Group 1≤Group 2 on both SS-OCT and micro-CT images. The %DSs on micro-CT were lower than SS-OCT (p<0.05) and the Pearson correlation coefficient between SS-OCT and micro-CT was r=0.787 (p<0.05).

    (26614427) – as supplied by publisher]

    Bibliography

  • 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.

    Microsc Microanal. 2015 Nov 23;:1-7

    Authors: Makishi P, Pacheco RR, Sadr A, Shimada Y, Sumi Y, Tagami J, Giannini M

    Abstract
    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 signal intensity at the bonded interface as evidence of internal gaps. SBS data were analyzed by one-way analysis of variance and Tukey’s test and IA data (% distribution of high brightness values) by Kruskal-Wallis and Dunn’s test (p≤0.05). No statistically significant difference in SBS was observed between VTF (13.9±3.6 MPa) and FLD (11.3±3.2 MPa), whereas OBF/HP showed higher average strength (27.3±6.1 MPa). However, there was a statistically significant difference in IA when VTF (33.3%) was compared with FLD (1.2%) and OBF/HP (1.5%). The conventional restorative system exhibited superior SBS performance compared with SARs. However, the IA of FLD to dentin had values that were not significantly different from OBF/HP.

    (26592427) – as supplied by publisher]

    Bibliography

  • 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.

    Microsc Microanal. 2015 Nov 23;:1-7

    Authors: Makishi P, Pacheco RR, Sadr A, Shimada Y, Sumi Y, Tagami J, Giannini M

    Abstract
    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 signal intensity at the bonded interface as evidence of internal gaps. SBS data were analyzed by one-way analysis of variance and Tukey’s test and IA data (% distribution of high brightness values) by Kruskal-Wallis and Dunn’s test (p≤0.05). No statistically significant difference in SBS was observed between VTF (13.9±3.6 MPa) and FLD (11.3±3.2 MPa), whereas OBF/HP showed higher average strength (27.3±6.1 MPa). However, there was a statistically significant difference in IA when VTF (33.3%) was compared with FLD (1.2%) and OBF/HP (1.5%). The conventional restorative system exhibited superior SBS performance compared with SARs. However, the IA of FLD to dentin had values that were not significantly different from OBF/HP.

    (26592427) – as supplied by publisher]

    Bibliography

  • Thirty six-month clinical evaluation of a highly-filled flowable composite for direct posterior restorations.
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    Thirty six-month clinical evaluation of a highly-filled flowable composite for direct posterior restorations.

    Aust Dent J. 2015 Nov 17;

    Authors: Kitasako Y, Sadr A, Burrow MF, Tagami J

    Abstract
    BACKGROUND: The aim of this randomized controlled study was to evaluate the clinical performance of a highly-filled flowable composite compared to a conventional paste-type composite in direct posterior restorations after 36 months.
    METHODS: A total of 58 mid-size to extensive posterior composite restorations were randomly placed in 32 patients, mean age of 43.9 years (range 25-76), using either a conventional composite Estelite Sigma Quick (Conventional) or a highly-filled flowable composite G-aenial Universal Flo with a 2-step self-etch adhesive. The restorations were evaluated after placement (baseline) and at 6, 12, 24 and 36 months according to the FDI criteria.
    RESULTS: At the 36-month follow-up, 42 restorations were evaluated in 21 patients. After 36 months, the difference between heavily-filled flowable and conventional restorations was not statistically significant with respect to all evaluation parameters (p<0.05). No secondary caries was observed.
    CONCLUSION: The highly filled flowable composite showed a comparable clinical effectiveness as the conventional paste composite in posterior restorations over 36-months. This article is protected by copyright. All rights reserved.

    (26573239) – as supplied by publisher]

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  • Initial and long-term bond strengths of one-step self-etch adhesives with silane coupling agent to enamel-dentin-composite in combined situation.
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    Initial and long-term bond strengths of one-step self-etch adhesives with silane coupling agent to enamel-dentin-composite in combined situation.

    Dent Mater J. 2015;34(5):663-670

    Authors: Mamanee T, Takahashi M, Nakajima M, M Foxton R, Tagami J

    Abstract
    This study evaluated the effect of adding silane coupling agent on initial and long-term bond strengths of one-step self-etch adhesives to enamel-dentin-composite in combined situation. Cervical cavities were prepared on extracted molars and filled with Clearfil AP-X. After water-storage for one-week, the filled teeth were sectioned in halves to expose enamel, dentin and composite surfaces and then enamel-dentin-composite surface was totally applied with one of adhesive treatments (Clearfil SE One, Clearfil SE One with Clearfil Porcelain Bond Activator, Beautibond Multi, Beautibond Multi with Beautibond Multi PR Plus and Scotchbond Universal). After designed period, micro-shear bond strengths (µSBSs) to each substrate were determined. For each period of water-storage, additive silane treatments significantly increased µSBS to composite (p<0.001). On the other hand, they significantly decreased µSBS to dentin (p<0.001), although did not have adverse effect on µSBS to enamel (p>0.05). Moreover, the stability of µSBS was depended on materials and substrates used.

    (26438990) – as supplied by publisher]

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  • Nanoleakage in Hybrid Layer and Acid-Base Resistant Zone at the Adhesive/Dentin Interface.
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    Nanoleakage in Hybrid Layer and Acid-Base Resistant Zone at the Adhesive/Dentin Interface.

    Microsc Microanal. 2015 Sep 9;:1-7

    Authors: Nikaido T, Nurrohman H, Takagaki T, Sadr A, Ichinose S, Tagami J

    Abstract
    The aim of interfacial nanoleakage evaluation is to gain a better understanding of degradation of the adhesive-dentin interface. The acid-base resistant zone (ABRZ) is recognized at the bonded interface under the hybrid layer (HL) in self-etch adhesive systems after an acid-base challenge. The purpose of this study was to evaluate nanoleakage in HL and ABRZ using three self-etch adhesives; Clearfil SE Bond (SEB), Clearfil SE One (SEO), and G-Bond Plus (GBP). One of the three adhesives was applied on the ground dentin surface and light cured. The specimens were longitudinally divided into two halves. One half remained as the control group. The others were immersed in ammoniacal silver nitrate solution, followed by photo developing solution under fluorescent light. Following this, the specimens were subjected to acid-base challenges with an artificial demineralization solution (pH4.5) and sodium hypochlorite, and prepared in accordance with common procedures for transmission electron microscopy (TEM) examination. The TEM images revealed silver depositions in HL and ABRZ due to nanoleakage in all the adhesives; however, the extent of nanoleakage was material dependent. Funnel-shaped erosion beneath the ABRZ was observed only in the all-in-one adhesive systems; SEO and GBP, but not in the two-step self-etch adhesive system; SEB.

    (26350420) – as supplied by publisher]

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  • Application of Optical Coherence Tomography (OCT) for Diagnosis of Caries, Cracks, and Defects of Restorations.
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    Application of Optical Coherence Tomography (OCT) for Diagnosis of Caries, Cracks, and Defects of Restorations.

    Curr Oral Health Rep. 2015;2(2):73-80

    Authors: Shimada Y, Sadr A, Sumi Y, Tagami J

    Abstract
    Optical coherence tomography (OCT) is a noninvasive technique providing cross-sectional images of a tooth structure. This review describes the use of OCT for detecting dental caries, tooth fractures, and interfacial gaps in intraoral restorations. OCT can be a reliable and an accurate method and a safer alternative to X-ray radiography.

    (26317064) – as supplied by publisher]

    Bibliography

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

    J Adhes Dent. 2015 Aug 4;

    Authors: Yoshimine N, Shimada Y, Tagami J, Sadr A

    Abstract
    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 optical coherence tomography (SS-OCT) before and after photopolymerization of the composite. Gap formation during polymerization or the difference in floor interface (DFI%) and final unsealed interface (USI%) were measured by image coregistration and subtraction on 6 diametrical planes across each scan.
    RESULTS: Two-way ANOVA suggested that both factors (adhesive and filling technique) and their interaction were significant (p < 0.001). SE2 showed significantly lower DFI% than did TSP when the composites were placed in bulk, but no difference was found when flowable lining was applied (p < 0.05). Within TSP, all filling techniques were significantly different and the lining group showed the lowest values, followed by ESQ-bulk. Overall, SE2 always showed lower UFI% than did TSP, while there was no difference among different techniques within SE2.
    CONCLUSION: SS-OCT is a unique method to observe the pre-existing interfacial defects and gaps developed during polymerization, which were found to depend on both placement technique and applied adhesive.

    (26258175) – as supplied by publisher]

    Bibliography

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

    Dent Mater J. 2015;34(4):545-52

    Authors: Ibusuki T, Kitasako Y, Sadr A, Shimada Y, Sumi Y, Tagami J

    Abstract
    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 CLSM and LM (r=0.85). Six WSLs were also evaluated clinically using SS-OCT; clear in-depth images of these natural WSLs were obtained in vivo. SS-OCT appears to be an effective tool for observation of the internal structure of WSLs, enabling quantitative assessment of WSL depth. Such data can be considered in the clinical management of WSLs.

    (26235722) – in process]

    Bibliography

  • Effect of polymer-based desensitizer with sodium fluoride on prevention of root dentin demineralization.
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    Effect of polymer-based desensitizer with sodium fluoride on prevention of root dentin demineralization.

    Am J Dent. 2015 Jun;28(3):123-7

    Authors: Oshima M, Hamba H, Sadr A, Nikaido T, Tagami J

    Abstract
    PURPOSE: To evaluate the effect of a fluoride-containing polymer-based desensitizer on prevention of root demineralization using micro-computed tomography (micro-CT).
    METHODS: Bovine root dentin blocks were divided into four groups; no treatment (Control); 1% oxalic acid (OA); MS Coat One containing methacrylate-co-p-styrene sulfonic acid (MS polymer) and 1% oxalic acid (MSO); and MS Coat F containing MS polymer, 1% oxalic acid and 3,000 ppm sodium fluoride (MSF). A window of the dentin surface was treated with each solution. The blocks were scanned using micro-CT after demineralization (pH 4.5, 5 hours). The dentin surfaces before and after demineralization were examined by scanning electron microscopy (SEM). Fluoride ion release was measured using a fluoride ion-specific electrode. The data were statistically analyzed using one-way ANOVA and Tukey’s test (α = 0.05).
    RESULTS: MSF showed the lowest mineral loss (80.4 ± 10.6 vol% x μm), which was significantly different from Control (99.4 ± 13.0 vol% x μm), OA (91.1 ± 10.9 vol% x μm) and MSO (89.1 ± 9.2 vol% x μm). Under the SEM observations, the dentin tubules appeared to be blocked after all desensitizer treatments. After demineralization, the exposure of dentin tubules was clearer in OA and MSO compared to MSF which showed sealed dentin tubules after demineralization. Fluoride ion release was detected only in the MSF group.

    (26201221) – in process]

    Bibliography

  • Assessment of natural enamel lesions with optical coherence tomography in comparison with microfocus x-ray computed tomography.

    Assessment of natural enamel lesions with optical coherence tomography in comparison with microfocus x-ray computed tomography.

    J Med Imaging (Bellingham). 2015 Jan;2(1):014001

    Authors: Espigares J, Sadr A, Hamba H, Shimada Y, Otsuki M, Tagami J, Sumi Y

    Abstract
    A technology to characterize early enamel lesions is needed in dentistry. Optical coherence tomography (OCT) is a noninvasive method that provides high-resolution cross-sectional images. The aim of this study is to compare OCT with microfocus x-ray computed tomography ([Formula: see text]) for assessment of natural enamel lesions in vitro. Ten human teeth with visible white spot-like changes on the enamel smooth surface and no cavitation (ICDAS code 2) were subjected to imaging by μCT (SMX-100CT, Shimadzu) and 1300-nm swept-source OCT (Dental SS-OCT, Panasonic Health Care). In [Formula: see text], the lesions appeared as radiolucent dark areas, while in SS-OCT, they appeared as areas of increased signal intensity beneath the surface. An SS-OCT attenuation coefficient based on Beer-Lambert law could discriminate lesions from sound enamel. Lesion depth ranged from 175 to [Formula: see text] in SS-OCT. A correlation between [Formula: see text] and SS-OCT was found regarding lesion depth ([Formula: see text], [Formula: see text]) and also surface layer thickness ([Formula: see text], [Formula: see text]). The images obtained clinically in real time using the dental SS-OCT system are suitable for the assessment of natural subsurface lesions and their surface layer, providing comparable images to a laboratory high-resolution [Formula: see text] without the use of x-ray.

    (26158079)]

    Bibliography

  • Inhibition of hydroxyapatite growth by casein, a potential salivary phosphoprotein homologue.

    Inhibition of hydroxyapatite growth by casein, a potential salivary phosphoprotein homologue.

    Eur J Oral Sci. 2015 Jun 17;

    Authors: Romero MJ, Nakashima S, Nikaido T, Ichinose S, Sadr A, Tagami J

    Abstract
    Salivary phosphoproteins are essential in tooth mineral regulation but are often overlooked in vitro. This study aimed to evaluate the effect of casein, as a salivary phosphoprotein homologue, on the deposition and growth of hydroxyapatite (HA) on tooth surfaces. Hydroxyapatite growth was quantified using seeded crystal systems. Artificial saliva (AS) containing HA powder and 0, 10, 20, 50, or 100 μg ml(-1) of casein, or 100 μg ml(-1) of dephosphorylated casein (Dcasein), was incubated for 0-8 h at 37°C, pH 7.2. Calcium concentrations were measured using atomic absorption spectroscopy (AAS). Surface precipitation of HA on bovine enamel and dentine blocks, incubated in similar conditions for 7 d, was examined using field emission scanning electron microscopy (FE-SEM) and transmission electron microscopy (TEM) with selected area electron diffraction (SAED). Casein adsorption was assessed using modified Lowry assays and zeta-potential measurements. The AAS results revealed a concentration-dependent inhibition of calcium consumption. Hydroxyapatite precipitation occurred when no casein was present, whereas precipitation of HA was apparently completely inhibited in casein-containing groups. Adsorption data demonstrated increasingly negative zeta-potential with increased casein concentration and an affinity constant similar to proline-rich proteins with Langmuir modelling. Casein inhibited the deposition and growth of HA primarily through the binding of esterized phosphate to HA active sites, indicating its potential as a mineral-regulating salivary phosphoprotein homologue in vitro.

    (26083784) – as supplied by publisher]

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