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  • 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).

    Dent Mater. 2016 Jul 16;

    Authors: Zhou Y, Shimada Y, Matin K, Sadr A, Sumi Y, Tagami J

    Abstract
    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 group were incubated for 2 weeks without biofilms. After SS-OCT observation, specimens were cut and examined under confocal laser scanning microscope (CLSM). The lesion depth (LD), interfacial gap depth (GD) and gap length (GL) obtained from SS-OCT and CLSM were analyzed by Pearson’s correlation, LD by Independent-samples t-test, GD and GL by Welch t-test, the frequency of specimens with or without gap by Fisher’s exact test at the 95% significant level.
    RESULTS: Specimens with interfacial gaps in the demineralized group showed significantly higher frequency than that in the control group (p<0.05). There was a significant correlation between SS-OCT and CLSM values of LD, GD and GL (p<0.05). SE showed significantly larger LD of dentin, but less GD and GL of enamel than TS (p<0.05).
    SIGNIFICANCE: SS-OCT nondestructively detected demineralization around composite restorations and interfacial gaps created by S. mutans biofilm in this in vitro model.

    (27435052) – as supplied by publisher]

    Bibliography

  • 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).

    Dent Mater. 2016 Jul 16;

    Authors: Zhou Y, Shimada Y, Matin K, Sadr A, Sumi Y, Tagami J

    Abstract
    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 group were incubated for 2 weeks without biofilms. After SS-OCT observation, specimens were cut and examined under confocal laser scanning microscope (CLSM). The lesion depth (LD), interfacial gap depth (GD) and gap length (GL) obtained from SS-OCT and CLSM were analyzed by Pearson’s correlation, LD by Independent-samples t-test, GD and GL by Welch t-test, the frequency of specimens with or without gap by Fisher’s exact test at the 95% significant level.
    RESULTS: Specimens with interfacial gaps in the demineralized group showed significantly higher frequency than that in the control group (p<0.05). There was a significant correlation between SS-OCT and CLSM values of LD, GD and GL (p<0.05). SE showed significantly larger LD of dentin, but less GD and GL of enamel than TS (p<0.05).
    SIGNIFICANCE: SS-OCT nondestructively detected demineralization around composite restorations and interfacial gaps created by S. mutans biofilm in this in vitro model.

    (27435052) – as supplied by publisher]

    Bibliography

  • 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.

    Dent Mater. 2016 Jul 14;

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

    Abstract
    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. The gap along the enamel-composite interface was recorded on each adhesive system. Confirmatory direct observation was accomplished at the same location using confocal laser scanning microscope.
    RESULTS: The demineralized enamel around the restorations was observed as a zone of intensified brightness in SS-OCT. The demineralized lesion on the cervical enamel was significantly deeper than that on the occlusal enamel (p<0.05). However, the extension of enamel demineralization at the enamel-composite interface was significantly deeper at the occlusal wall than the cervical wall (p<0.05). The extension in Tri-S Bond ND group was significantly deeper than in SE Bond group (p<0.05). A significant increase in gap formation was found after the extension of demineralization compared with the baseline.
    SIGNIFICANCE: The carious demineralization around composite restorations were observed as a bright zone in SS-OCT during the process of bacterial demineralization. SS-OCT appears to be a promising modality for the detection of caries adjacent to an existing restoration.

    (27427292) – as supplied by publisher]

    Bibliography

  • 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.

    Dent Mater. 2016 Jul 14;

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

    Abstract
    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. The gap along the enamel-composite interface was recorded on each adhesive system. Confirmatory direct observation was accomplished at the same location using confocal laser scanning microscope.
    RESULTS: The demineralized enamel around the restorations was observed as a zone of intensified brightness in SS-OCT. The demineralized lesion on the cervical enamel was significantly deeper than that on the occlusal enamel (p<0.05). However, the extension of enamel demineralization at the enamel-composite interface was significantly deeper at the occlusal wall than the cervical wall (p<0.05). The extension in Tri-S Bond ND group was significantly deeper than in SE Bond group (p<0.05). A significant increase in gap formation was found after the extension of demineralization compared with the baseline.
    SIGNIFICANCE: The carious demineralization around composite restorations were observed as a bright zone in SS-OCT during the process of bacterial demineralization. SS-OCT appears to be a promising modality for the detection of caries adjacent to an existing restoration.

    (27427292) – as supplied by publisher]

    Bibliography

  • 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.

    Dent Mater. 2016 Jun 29;

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

    Abstract
    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 3mm in diameter were prepared in 100 human third molars in two depths: 4mm high C-factor (H-CF) or 1mm 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, 3M 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 Bulk Fill (VB, Heraeus Kulzer). After thermo-mechanical load-cycles, imperfect margin percentage (%IM) was calculated using swept-source optical coherence tomography (SS-OCT) imaging. The relationships between %IM and linear shrinkage (LS) and shrinkage stress, measured under either zero-compliance (PS0) or compliance-allowed (PS) conditions were evaluated.
    RESULTS: The %IM was significantly different between H-CF and L-CF groups. The %IM in H-CF turned out to be as groups CD, FS≤TB<AP, VB. The %IM in L-CF showed as groups CD, TB≤FS, AP<VB. There were significant correlations between shrinkage parameters and %IM, except between PS0 and %IM in L-CF.
    SIGNIFICANCE: Internal adaptation in a high C-factor cavity was inferior to that in a low C-factor cavity for both conventional and bulk-filled composites. Internal adaptation, polymerization shrinkage, and stress were different among composite materials. Polymerization stress under the compliance-allowed condition showed significant correlations with internal adaptations in high and low C-factor cavities.

    (27372237) – as supplied by publisher]

    Bibliography

  • 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.

    Dent Mater. 2016 Jun 29;

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

    Abstract
    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 3mm in diameter were prepared in 100 human third molars in two depths: 4mm high C-factor (H-CF) or 1mm 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, 3M 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 Bulk Fill (VB, Heraeus Kulzer). After thermo-mechanical load-cycles, imperfect margin percentage (%IM) was calculated using swept-source optical coherence tomography (SS-OCT) imaging. The relationships between %IM and linear shrinkage (LS) and shrinkage stress, measured under either zero-compliance (PS0) or compliance-allowed (PS) conditions were evaluated.
    RESULTS: The %IM was significantly different between H-CF and L-CF groups. The %IM in H-CF turned out to be as groups CD, FS≤TB<AP, VB. The %IM in L-CF showed as groups CD, TB≤FS, AP<VB. There were significant correlations between shrinkage parameters and %IM, except between PS0 and %IM in L-CF.
    SIGNIFICANCE: Internal adaptation in a high C-factor cavity was inferior to that in a low C-factor cavity for both conventional and bulk-filled composites. Internal adaptation, polymerization shrinkage, and stress were different among composite materials. Polymerization stress under the compliance-allowed condition showed significant correlations with internal adaptations in high and low C-factor cavities.

    (27372237) – as supplied by publisher]

    Bibliography

  • Dentin bonding performance using Weibull statistics and evaluation of acid-base resistant zone formation of recently introduced adhesives.

    Dentin bonding performance using Weibull statistics and evaluation of acid-base resistant zone formation of recently introduced adhesives.

    Dent Mater J. 2016 Jun 23;

    Authors: Guan R, Takagaki T, Matsui N, Sato T, Burrow MF, Palamara J, Nikaido T, Tagami J

    Abstract
    Dentin bonding durability of recently introduced dental adhesives: Clearfil SE Bond 2 (SE2), Optibond XTR (XTR), and Scotchbond Universal (SBU) was investigated using Weibull analysis as well as analysis of the micromorphological features of the acid-base resistant zone (ABRZ) created for the adhesives. The bonding procedures of SBU were divided into three subgroups: self-etch (SBS), phosphoric acid (PA) etching on moist (SBM) or dry dentin (SBD). All groups were thermocycled for 0, 5,000 and 10,000 cycles followed by microtensile bond strength testing. Acid-base challenge was undertaken before SEM and TEM observations of the adhesive interface. The etch-and-rinse method with SBU (SBM and SBD) created inferior interfaces on the dentin surface which resulted in reduced bond durability. ABRZ formation was detected with the self-etch adhesive systems; SE2, XTR and SBS. In the PA etching protocols of SBM and SBD, a thick hybrid layer but no ABRZ was detected, which might affect dentin bond durability.

    (27335136) – as supplied by publisher]

    Bibliography

  • Dentin bonding performance using Weibull statistics and evaluation of acid-base resistant zone formation of recently introduced adhesives.

    Dentin bonding performance using Weibull statistics and evaluation of acid-base resistant zone formation of recently introduced adhesives.

    Dent Mater J. 2016 Jun 23;

    Authors: Guan R, Takagaki T, Matsui N, Sato T, Burrow MF, Palamara J, Nikaido T, Tagami J

    Abstract
    Dentin bonding durability of recently introduced dental adhesives: Clearfil SE Bond 2 (SE2), Optibond XTR (XTR), and Scotchbond Universal (SBU) was investigated using Weibull analysis as well as analysis of the micromorphological features of the acid-base resistant zone (ABRZ) created for the adhesives. The bonding procedures of SBU were divided into three subgroups: self-etch (SBS), phosphoric acid (PA) etching on moist (SBM) or dry dentin (SBD). All groups were thermocycled for 0, 5,000 and 10,000 cycles followed by microtensile bond strength testing. Acid-base challenge was undertaken before SEM and TEM observations of the adhesive interface. The etch-and-rinse method with SBU (SBM and SBD) created inferior interfaces on the dentin surface which resulted in reduced bond durability. ABRZ formation was detected with the self-etch adhesive systems; SE2, XTR and SBS. In the PA etching protocols of SBM and SBD, a thick hybrid layer but no ABRZ was detected, which might affect dentin bond durability.

    (27335136) – as supplied by publisher]

    Bibliography

  • Dentin bonding performance and interface observation of an MMA-based restorative material.

    Dentin bonding performance and interface observation of an MMA-based restorative material.

    Dent Mater J. 2016 Jun 23;

    Authors: Shinagawa J, Inoue G, Nikaido T, Ikeda M, Sadr A, Tagami J

    Abstract
    The purpose of this study was to evaluate bonding performance and dentin interface acid resistance using a 4-META/MMA-TBB based restorative material (BF) compared to a conventional 4-META/MMA-TBB resin cement (SB), and the effect of sodium fluoride (NaF) addition to the materials. Dentin surfaces were treated with 10% citric acid-3% ferric chloride (10-3) or 4-META containing self-etching primer (TP), followed by application of BF or SB polymer powders with or without NaF, to evaluate microtensile bond strength (µTBS) in six experimental groups; 10-3/SB, 10-3/BF, TP/SB, TP/BF, TP/SB/NaF and TP/BF/NaF. SEM observation of the resin-dentin interface was performed after acid-base challenge to evaluate interfacial dentin resistance to acid attack. TP/BF showed highest µTBS, while NaF polymers decreased µTBS. TP/BF showed funnel-shaped erosion at the interface, however, NaF polymers improved acid resistance of interface. In conclusion, BF demonstrated high µTBSs and low acid-resistance at the interface. NaF addition enhanced acid resistance but decreased µTBS.

    (27335135) – as supplied by publisher]

    Bibliography

  • Dentin bonding performance and interface observation of an MMA-based restorative material.

    Dentin bonding performance and interface observation of an MMA-based restorative material.

    Dent Mater J. 2016 Jun 23;

    Authors: Shinagawa J, Inoue G, Nikaido T, Ikeda M, Sadr A, Tagami J

    Abstract
    The purpose of this study was to evaluate bonding performance and dentin interface acid resistance using a 4-META/MMA-TBB based restorative material (BF) compared to a conventional 4-META/MMA-TBB resin cement (SB), and the effect of sodium fluoride (NaF) addition to the materials. Dentin surfaces were treated with 10% citric acid-3% ferric chloride (10-3) or 4-META containing self-etching primer (TP), followed by application of BF or SB polymer powders with or without NaF, to evaluate microtensile bond strength (µTBS) in six experimental groups; 10-3/SB, 10-3/BF, TP/SB, TP/BF, TP/SB/NaF and TP/BF/NaF. SEM observation of the resin-dentin interface was performed after acid-base challenge to evaluate interfacial dentin resistance to acid attack. TP/BF showed highest µTBS, while NaF polymers decreased µTBS. TP/BF showed funnel-shaped erosion at the interface, however, NaF polymers improved acid resistance of interface. In conclusion, BF demonstrated high µTBSs and low acid-resistance at the interface. NaF addition enhanced acid resistance but decreased µTBS.

    (27335135) – as supplied by publisher]

    Bibliography

  • Influence of water immersion on the mechanical properties of fiber posts.
    .

    Influence of water immersion on the mechanical properties of fiber posts.

    J Prosthodont Res. 2016 Jun 17;

    Authors: Komada W, Inagaki T, Ueda Y, Omori S, Hosaka K, Tagami J, Miura H

    Abstract
    PURPOSE: The purpose of this study was to evaluate the influence of water immersion on the mechanical properties of three kinds of glass fiber posts and the fracture resistance of structures using resin composites with glass fiber posts.
    METHODS: Each post was divided into three groups; a control group and two water immersion groups (30 and 90 days). Flexural strength was determined by three-point bending test. Each structure was divided into two groups; a control group and a water immersion group for 30 days. The fracture strength of structures was determined by a static loading test.
    RESULTS: In the flexural strength, two kinds of post in water immersion groups showed lower values than control groups. In the fracture strength, two kinds of structures in water immersion group showed lower values than control groups.
    CONCLUSION: The prefabricated glass fiber posts and structures using resin composites with glass fiber posts were affected by water immersion.

    (27324293) – as supplied by publisher]

    Bibliography

  • Influence of water immersion on the mechanical properties of fiber posts.
    .

    Influence of water immersion on the mechanical properties of fiber posts.

    J Prosthodont Res. 2016 Jun 17;

    Authors: Komada W, Inagaki T, Ueda Y, Omori S, Hosaka K, Tagami J, Miura H

    Abstract
    PURPOSE: The purpose of this study was to evaluate the influence of water immersion on the mechanical properties of three kinds of glass fiber posts and the fracture resistance of structures using resin composites with glass fiber posts.
    METHODS: Each post was divided into three groups; a control group and two water immersion groups (30 and 90 days). Flexural strength was determined by three-point bending test. Each structure was divided into two groups; a control group and a water immersion group for 30 days. The fracture strength of structures was determined by a static loading test.
    RESULTS: In the flexural strength, two kinds of post in water immersion groups showed lower values than control groups. In the fracture strength, two kinds of structures in water immersion group showed lower values than control groups.
    CONCLUSION: The prefabricated glass fiber posts and structures using resin composites with glass fiber posts were affected by water immersion.

    (27324293) – as supplied by publisher]

    Bibliography

  • Effect of thermal cyclic stress on acid resistance of resin-infiltrated incipient enamel lesions in vitro.

    Effect of thermal cyclic stress on acid resistance of resin-infiltrated incipient enamel lesions in vitro.

    Dent Mater J. 2016;35(3):425-31

    Authors: Takashino N, Nakashima S, Shimada Y, Tagami J, Sumi Y

    Abstract
    This study aimed to examine the effect of thermal cycling on gap formation at the interface between infiltrated resin (ICON(®)) and enamel lesion and on the durability of anti-demineralization efficacy to predict the future performance. SS-OCT technique was examined to determine whether it has the potential to detect the gap. Bovine enamel lesions were prepared, and the infiltrated resin was applied to the lesion. Resin-infiltrated lesion specimens were thermal cycled 10,000 cycles and further demineralized in pH 4.5 buffer for 7 days. Released Ca (mg/cm(2)) was quantified by Ca electrode. The SS-OCT technique was applied to detect the gap, and SEM observation was performed to determine the presence of the gap. There was no significant difference in the amount of Ca release before and after the thermal cycling, suggesting long-lasting anti-demineralization efficacy of the resin. SS-OCT and SEM observations indicated no apparent gap formation after the thermal cycling.

    (27251998) – in process]

    Bibliography

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

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

    Dent Mater J. 2016;35(3):432-9

    Authors: Ito S, Shimada Y, Sadr A, Nakajima Y, Miyashin M, Tagami J, Sumi Y

    Abstract
    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 SS-OCT was higher than that of visual inspection for fissure depth. Additionally, clear cross-sectional images of sealant penetration into fissures were observed with SS-OCT. SS-OCT can be used to evaluate fissure depth and monitor sealant penetration.

    (27251999) – in process]

    Bibliography

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

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

    Dent Mater J. 2016;35(3):432-9

    Authors: Ito S, Shimada Y, Sadr A, Nakajima Y, Miyashin M, Tagami J, Sumi Y

    Abstract
    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 SS-OCT was higher than that of visual inspection for fissure depth. Additionally, clear cross-sectional images of sealant penetration into fissures were observed with SS-OCT. SS-OCT can be used to evaluate fissure depth and monitor sealant penetration.

    (27251999) – in process]

    Bibliography

  • Effect of thermal cyclic stress on acid resistance of resin-infiltrated incipient enamel lesions in vitro.

    Effect of thermal cyclic stress on acid resistance of resin-infiltrated incipient enamel lesions in vitro.

    Dent Mater J. 2016;35(3):425-31

    Authors: Takashino N, Nakashima S, Shimada Y, Tagami J, Sumi Y

    Abstract
    This study aimed to examine the effect of thermal cycling on gap formation at the interface between infiltrated resin (ICON(®)) and enamel lesion and on the durability of anti-demineralization efficacy to predict the future performance. SS-OCT technique was examined to determine whether it has the potential to detect the gap. Bovine enamel lesions were prepared, and the infiltrated resin was applied to the lesion. Resin-infiltrated lesion specimens were thermal cycled 10,000 cycles and further demineralized in pH 4.5 buffer for 7 days. Released Ca (mg/cm(2)) was quantified by Ca electrode. The SS-OCT technique was applied to detect the gap, and SEM observation was performed to determine the presence of the gap. There was no significant difference in the amount of Ca release before and after the thermal cycling, suggesting long-lasting anti-demineralization efficacy of the resin. SS-OCT and SEM observations indicated no apparent gap formation after the thermal cycling.

    (27251998) – in process]

    Bibliography

  • Morphological Evaluation of the Adhesive/Enamel interfaces of Two-step Self-etching Adhesives and Multimode One-bottle Self-etching Adhesives.
    .

    Morphological Evaluation of the Adhesive/Enamel interfaces of Two-step Self-etching Adhesives and Multimode One-bottle Self-etching Adhesives.

    J Adhes Dent. 2016 May 19;

    Authors: Sato T, Takagaki T, Matsui N, Hamba H, Sadr A, Nikaido T, Tagami J

    Abstract
    PURPOSE: To evaluate the acid-base resistant zone (ABRZ) at the adhesive/enamel interface of self-etching adhesives with or without prior phosphoric acid etching.
    MATERIALS AND METHODS: Four adhesives were used in 8 groups: Clearfil SE Bond (SEB), Optibond XTR (XTR), Scotchbond Universal Adhesive (SBU), and Clearfil BOND SE ONE (ONE) without prior phosphoric-acid etching, and each adhesive with phosphoric acid etching for 10 s (P-SEB, P-XTR, P-SBU and P-ONE, respectively). After application of self-etching adhesives on ground enamel surfaces of human teeth, a flowable composite was placed. For observation of the acid-base resistant zone (ABRZ), the bonded interface was exposed to demineralizing solution (pH 4.5) for 4.5 h, followed by 5% NaOCl with ultrasonication for 20 min. After the acid-base challenge, morphological attributes of the interface were observed using SEM.
    RESULTS: ABRZ formation was confirmed in all groups. The funnel-shaped erosion beneath the interface was present in SBU and ONE, where nearly 10 to 15 μm of enamel was dissolved. With phosphoric acid etching, the ABRZs were obviously thicker compared with no phosphoric acid etching.
    CONCLUSION: Enamel beneath the bonding interface was more susceptible to acid dissolution in SBU and ONE. In the case of the one-bottle self-etching adhesives and universal adhesives that intrinsically have higher pH values, enamel etching should be recommended to improve the interfacial quality.

    (27200432) – as supplied by publisher]

    Bibliography

  • Effect of Scrubbing Technique with Mild Self-etching Adhesives on Dentin Bond Strengths and Nanoleakage Expression.

    Effect of Scrubbing Technique with Mild Self-etching Adhesives on Dentin Bond Strengths and Nanoleakage Expression.

    J Adhes Dent. 2016 May 9;

    Authors: Thanatvarakorn O, Prasansuttiporn T, Takahashi M, Thittaweerat S, Foxton RM, Ichinose S, Tagami J, Nakajima M

    Abstract
    PURPOSE: To evaluate the effect of a scrubbing technique with one-step self-etching adhesives on bond strengths and nanoleakage expression at the resin/dentin interface.
    MATERIALS AND METHODS: Flat human dentin surfaces bonded with one of two mild self-etching adhesives, SE One (SE) or Scotchbond Universal (SU) applied either with scrubbing or without scrubbing technique, were prepared (n = 5). The microtensile bond strengths (μTBS), SE micrographs of morphological changes on treated dentin surfaces, and expression of nanoleakage along the bonded dentin interfaces as shown with TEM were evaluated. μTBS data were analyzed using two-way ANOVA and the post-hoc t-test at the significance level of 0.05.
    RESULTS: The scrubbing technique had a significant positive effect on the μTBS of SU (p < 0.05), while it produced no significant difference for SE (p > 0.05). Morphological evaluation of the treated dentin surfaces demonstrated that SU with scrubbing showed the highest etching ability, followed by scrubbing SE > nonscrubbing SE > nonscrubbing SU. In the nonscrubbing groups, nanoleakage formation using SU exhibited a reticular pattern throughout the hybridized complex, whereas with SE, water-tree nanoleakage was only found in the adhesive layer at dentinal tubule orifices. The scrubbing groups of both adhesives did not exhibit any nanoleakage expression.
    CONCLUSION: Using a scrubbing technique when applying mild self-etching adhesives could improve resin monomer infiltration into dentin, chase water on adhesive surfaces, and facilitate smear layer removal.

    (27163111) – as supplied by publisher]

    Bibliography

  • Effect of Scrubbing Technique with Mild Self-etching Adhesives on Dentin Bond Strengths and Nanoleakage Expression.

    Effect of Scrubbing Technique with Mild Self-etching Adhesives on Dentin Bond Strengths and Nanoleakage Expression.

    J Adhes Dent. 2016 May 9;

    Authors: Thanatvarakorn O, Prasansuttiporn T, Takahashi M, Thittaweerat S, Foxton RM, Ichinose S, Tagami J, Nakajima M

    Abstract
    PURPOSE: To evaluate the effect of a scrubbing technique with one-step self-etching adhesives on bond strengths and nanoleakage expression at the resin/dentin interface.
    MATERIALS AND METHODS: Flat human dentin surfaces bonded with one of two mild self-etching adhesives, SE One (SE) or Scotchbond Universal (SU) applied either with scrubbing or without scrubbing technique, were prepared (n = 5). The microtensile bond strengths (μTBS), SE micrographs of morphological changes on treated dentin surfaces, and expression of nanoleakage along the bonded dentin interfaces as shown with TEM were evaluated. μTBS data were analyzed using two-way ANOVA and the post-hoc t-test at the significance level of 0.05.
    RESULTS: The scrubbing technique had a significant positive effect on the μTBS of SU (p < 0.05), while it produced no significant difference for SE (p > 0.05). Morphological evaluation of the treated dentin surfaces demonstrated that SU with scrubbing showed the highest etching ability, followed by scrubbing SE > nonscrubbing SE > nonscrubbing SU. In the nonscrubbing groups, nanoleakage formation using SU exhibited a reticular pattern throughout the hybridized complex, whereas with SE, water-tree nanoleakage was only found in the adhesive layer at dentinal tubule orifices. The scrubbing groups of both adhesives did not exhibit any nanoleakage expression.
    CONCLUSION: Using a scrubbing technique when applying mild self-etching adhesives could improve resin monomer infiltration into dentin, chase water on adhesive surfaces, and facilitate smear layer removal.

    (27163111) – as supplied by publisher]

    Bibliography

  • 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