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  • 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.

    Dent Mater. 2016 Apr 11;

    Authors: Dao Luong MN, Shimada Y, Turkistani A, Tagami J, Sumi Y, Sadr A

    Abstract
    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 (0.9×0.9mm(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 1319nm center wavelength before MTBS test was performed at crosshead speed of either 1 or 10mm/min (n=10). The beams were scanned by SS-OCT again to detect and measure cracks at the debonded interface using digital image analysis software. Representative beams were observed under confocal laser scanning microscope to confirm the fractography findings.
    RESULTS: Two-way ANOVA showed that for MTBS the crosshead speed was not a significant factor (p>0.05), while there was a difference between placement techniques (p<0.001), with flowable lining yielding higher mean values. On the other hand, for crack formation, there was a significant difference between crosshead speeds (p<0.01), while the placement technique did not show up as a statistically significant factor (p>0.05). The interaction of factors were not significant (p>0.05).
    SIGNIFICANCE: Testing MTBS samples at higher crosshead speeds induced more cracks in dentin. Lining with a flowable composite improved the bonding quality and increased the bond strength. SS-OCT can visualize interfacial cracks after restoration debonding.

    (27080369) – as supplied by publisher]

    Bibliography

  • Effects of coating materials on nanoindentation hardness of enamel and adjacent areas.

    Effects of coating materials on nanoindentation hardness of enamel and adjacent areas.

    Dent Mater. 2016 Apr 7;

    Authors: Alsayed EZ, Hariri I, Nakashima S, Shimada Y, Bakhsh TA, Tagami J, Sadr A

    Abstract
    OBJECTIVES: Materials that can be applied as thin coatings and actively release fluoride or other bioavailable ions for reinforcing dental hard tissue deserve further investigation. In this study we assessed the potential of resin coating materials in protection of underlying and adjacent enamel against demineralization challenge using nanoindentation.
    METHODS: Enamel was coated using Giomer (PRG Barrier Coat, PBC), resin-modified glass-ionomer (Clinpro XT Varnish, CXT), two-step self-etch adhesive (Clearfil SE Protect, SEP) or no coating (control). After 5000 thermal cycles and one-week demineralization challenge, Martens hardness of enamel beneath the coating, uncoated area and intermediate areas was measured using a Berkovich tip under 2mN load up to 200μm depth. Integrated hardness and 10-μm surface zone hardness were compared among groups.
    RESULTS: Nanoindentation and scanning electron microscopy suggested that all materials effectively prevented demineralization in coated area. Uncoated areas presented different hardness trends; PBC showed a remarkable peak at the surface zone before reaching as low as the control, while CXT showed relatively high hardness values at all depths.
    SIGNIFICANCE: Ion-release from coating materials affects different layers of enamel. Coatings with fluoride-releasing glass fillers contributed to reinforcement of adjacent enamel. Surface prereacted glass filler-containing PBC superficially protected neighboring enamel against demineralization, while resin-modified glass-ionomer with calcium (CXT) improved in-depth protection. Cross-sectional hardness mapping of enamel on a wide range of locations revealed minute differences in its structure.

    (27063457) – as supplied by publisher]

    Bibliography

  • In vitro dentine remineralization with a potential salivary phosphoprotein homologue.

    In vitro dentine remineralization with a potential salivary phosphoprotein homologue.

    Arch Oral Biol. 2016 Mar 23;68:35-42

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

    Abstract
    OBJECTIVE: Advantages of introducing a salivary phosphoprotein homologue under standardized in vitro conditions to simulate the mineral-stabilizing properties of saliva have been proposed. This study longitudinally investigates the effects of casein, incorporated as a potential salivary phosphoprotein homologue in artificial saliva (AS) solutions with/without fluoride (F) on in vitro dentine lesion remineralization.
    DESIGN: Thin sections of bovine root dentine were demineralized and allocated randomly into 6 groups (n=18) having equivalent mineral loss (ΔZ) after transverse microradiography (TMR). The specimens were remineralized using AS solutions containing casein 0μg/ml, F 0ppm (C0-F0); casein 0μg/ml, F 1ppm (C0-F1); casein 10μg/ml, F 0ppm (C10-F0); casein 10μg/ml, F 1ppm (C10-F1); casein 100μg/ml, F 0ppm (C100-F0) or casein 100μg/ml, F 1ppm (C100-F1) for 28days with TMR taken every 7 days.
    RESULTS: Surface mineral precipitation, evident in group C0-F1, was apparently inhibited in groups with casein incorporation. Repeated measures ANOVA with Bonferroni correction revealed higher ΔZ for non-F and non-casein groups than for their counterparts (p<0.001). Subsequent multiple comparisons showed that mineral gain was higher (p<0.001) with 10μg/ml casein than with 100μg/ml when F was present in the earlier stages of remineralization, with both groups achieving almost complete remineralization after 28 days.
    CONCLUSION: Casein is a potential salivary phosphoprotein homologue that could be employed for in vitro dentine remineralization studies. Concentration related effects may be clinically significant and thus must be further examined.

    (27054701) – as supplied by publisher]

    Bibliography

  • In vitro dentine remineralization with a potential salivary phosphoprotein homologue.

    In vitro dentine remineralization with a potential salivary phosphoprotein homologue.

    Arch Oral Biol. 2016 Mar 23;68:35-42

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

    Abstract
    OBJECTIVE: Advantages of introducing a salivary phosphoprotein homologue under standardized in vitro conditions to simulate the mineral-stabilizing properties of saliva have been proposed. This study longitudinally investigates the effects of casein, incorporated as a potential salivary phosphoprotein homologue in artificial saliva (AS) solutions with/without fluoride (F) on in vitro dentine lesion remineralization.
    DESIGN: Thin sections of bovine root dentine were demineralized and allocated randomly into 6 groups (n=18) having equivalent mineral loss (ΔZ) after transverse microradiography (TMR). The specimens were remineralized using AS solutions containing casein 0μg/ml, F 0ppm (C0-F0); casein 0μg/ml, F 1ppm (C0-F1); casein 10μg/ml, F 0ppm (C10-F0); casein 10μg/ml, F 1ppm (C10-F1); casein 100μg/ml, F 0ppm (C100-F0) or casein 100μg/ml, F 1ppm (C100-F1) for 28days with TMR taken every 7 days.
    RESULTS: Surface mineral precipitation, evident in group C0-F1, was apparently inhibited in groups with casein incorporation. Repeated measures ANOVA with Bonferroni correction revealed higher ΔZ for non-F and non-casein groups than for their counterparts (p<0.001). Subsequent multiple comparisons showed that mineral gain was higher (p<0.001) with 10μg/ml casein than with 100μg/ml when F was present in the earlier stages of remineralization, with both groups achieving almost complete remineralization after 28 days.
    CONCLUSION: Casein is a potential salivary phosphoprotein homologue that could be employed for in vitro dentine remineralization studies. Concentration related effects may be clinically significant and thus must be further examined.

    (27054701) – as supplied by publisher]

    Bibliography

  • 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.

    J Med Imaging (Bellingham). 2016 Jan;3(1):014504

    Authors: Tezuka H, Shimada Y, Matin K, Ikeda M, Sadr A, Sumi Y, Tagami J

    Abstract
    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. Statistical analyses were performed with 95% level of confidence. Cervical demineralization was displayed as a bright zone in SS-OCT. The demineralization depth of dentin was significantly deeper than that of enamel ([Formula: see text]). Enamel near the CEJ demonstrated a significant increase of AUC over the other enamel region after the demineralization. The gaps along the dentinoenamel junction were additionally observed in SS-OCT. SS-OCT was capable of monitoring the cervical demineralization induced by a cariogenic biofilm and is considered to be a promising modality for the diagnosis of cervical demineralization.

    (27014718)]

    Bibliography

  • Adsorption behavior of methacryloyloxydecyl dihydrogen phosphate on an apatite surface at neutral pH.
    .

    Adsorption behavior of methacryloyloxydecyl dihydrogen phosphate on an apatite surface at neutral pH.

    Eur J Oral Sci. 2016 Mar 2;

    Authors: Bista B, Nakashima S, Nikaido T, Sadr A, Takagaki T, Romero MJ, Sato T, Tagami J

    Abstract
    This study aimed to quantify the adsorption affinity of neutralized 10-methacryloyloxydecyl dihydrogen phosphate (10-MDP-N) toward hydroxyapatite (HA) and dicalcium phosphate dihydrate (DCPD) at pH 7.0 by employing the Langmuir isotherm model. Furthermore, the effects of inorganic phosphate (Pi) and fluoride (F(-) ) ions on the adsorption of 10-MDP-N onto HA and DCPD were examined. Fixed amounts of HA and DCPD powders were suspended in different concentrations of 10-MDP-N solutions and were incubated for 18 h. Equilibrated concentrations of 10-MDP-N were measured by spectrophotometry and the adsorption affinity was estimated using the Langmuir model. Moreover, the adsorption was examined by zeta-potential analysis. The results indicated that significant Langmuir correlation was noted in both substrates, along with an increasing negative zeta-potential; however, in DCPD the correlation was less strong. The addition of 1.0 mM Pi slightly delayed the adsorption of 10-MDP-N onto both substrates, whereas 3.0 mM Pi drastically delayed adsorption onto HA but completely inhibited adsorption onto DCPD. Up to 50 ppm, F(-) enhanced the adsorption onto HA, and the adsorption plateaued at higher concentrations of F(-) , whereas no obvious influence of F(-) on the adsorption onto DCPD was noted.

    (26932315) – as supplied by publisher]

    Bibliography

  • Adsorption behavior of methacryloyloxydecyl dihydrogen phosphate on an apatite surface at neutral pH.
    .

    Adsorption behavior of methacryloyloxydecyl dihydrogen phosphate on an apatite surface at neutral pH.

    Eur J Oral Sci. 2016 Mar 2;

    Authors: Bista B, Nakashima S, Nikaido T, Sadr A, Takagaki T, Romero MJ, Sato T, Tagami J

    Abstract
    This study aimed to quantify the adsorption affinity of neutralized 10-methacryloyloxydecyl dihydrogen phosphate (10-MDP-N) toward hydroxyapatite (HA) and dicalcium phosphate dihydrate (DCPD) at pH 7.0 by employing the Langmuir isotherm model. Furthermore, the effects of inorganic phosphate (Pi) and fluoride (F(-) ) ions on the adsorption of 10-MDP-N onto HA and DCPD were examined. Fixed amounts of HA and DCPD powders were suspended in different concentrations of 10-MDP-N solutions and were incubated for 18 h. Equilibrated concentrations of 10-MDP-N were measured by spectrophotometry and the adsorption affinity was estimated using the Langmuir model. Moreover, the adsorption was examined by zeta-potential analysis. The results indicated that significant Langmuir correlation was noted in both substrates, along with an increasing negative zeta-potential; however, in DCPD the correlation was less strong. The addition of 1.0 mM Pi slightly delayed the adsorption of 10-MDP-N onto both substrates, whereas 3.0 mM Pi drastically delayed adsorption onto HA but completely inhibited adsorption onto DCPD. Up to 50 ppm, F(-) enhanced the adsorption onto HA, and the adsorption plateaued at higher concentrations of F(-) , whereas no obvious influence of F(-) on the adsorption onto DCPD was noted.

    (26932315) – as supplied by publisher]

    Bibliography

  • 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.
    .

    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.
    .

    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.
    .

    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.
    .

    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]

    Bibliography

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

    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]

    Bibliography