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  • Three-Dimensional Analysis of Enamel Crack Behavior Using Optical Coherence Tomography.
    .

    Three-Dimensional Analysis of Enamel Crack Behavior Using Optical Coherence Tomography.

    J Dent Res. 2016 Nov 21;:

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

    Abstract
    The aim of this study was to nondestructively analyze enamel crack behavior on different areas of teeth using 3D swept source-optical coherence tomography (SS-OCT). Ten freshly extracted human teeth of each type on each arch (n = 80 teeth) were inspected for enamel crack patterns on functional, contact and nonfunctional, or noncontact areas using 3D SS-OCT. The predominant crack pattern for each location on each specimen was noted and analyzed. The OCT observations were validated by direct observations of sectioned specimens under confocal laser scanning microscopy (CLSM). Cracks appeared as bright lines with SS-OCT, with 3 crack patterns identified: Type I – superficial horizontal cracks; Type II – vertically (occluso-gingival) oriented cracks; and Type III – hybrid or complicated cracks, a combination of a Type I and Type III cracks, which may or may not be confluent with each other. Type II cracks were predominant on noncontacting surfaces of incisors and canines and nonfunctional cusps of posterior teeth. Type I and III cracks were predominant on the contacting surfaces of incisors, cusps of canines, and functional cusps of posterior teeth. Cracks originating from the dental-enamel junction and enamel tufts, crack deflections, and the initiation of new cracks within the enamel (internal cracks) were observed as bright areas. CLSM observations corroborated the SS-OCT findings. We found that crack pattern, tooth type, and the location of the crack on the tooth exhibited a strong correlation. We show that the use of 3D SS-OCT permits for the nondestructive 3D imaging and analysis of enamel crack behavior in whole human teeth in vitro. 3D SS-OCT possesses potential for use in clinical studies for the analysis of enamel crack behavior.

    (27872333) – as supplied by publisher]

    Bibliography

  • Three-Dimensional Analysis of Enamel Crack Behavior Using Optical Coherence Tomography.
    .

    Three-Dimensional Analysis of Enamel Crack Behavior Using Optical Coherence Tomography.

    J Dent Res. 2016 Nov 21;:

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

    Abstract
    The aim of this study was to nondestructively analyze enamel crack behavior on different areas of teeth using 3D swept source-optical coherence tomography (SS-OCT). Ten freshly extracted human teeth of each type on each arch (n = 80 teeth) were inspected for enamel crack patterns on functional, contact and nonfunctional, or noncontact areas using 3D SS-OCT. The predominant crack pattern for each location on each specimen was noted and analyzed. The OCT observations were validated by direct observations of sectioned specimens under confocal laser scanning microscopy (CLSM). Cracks appeared as bright lines with SS-OCT, with 3 crack patterns identified: Type I – superficial horizontal cracks; Type II – vertically (occluso-gingival) oriented cracks; and Type III – hybrid or complicated cracks, a combination of a Type I and Type III cracks, which may or may not be confluent with each other. Type II cracks were predominant on noncontacting surfaces of incisors and canines and nonfunctional cusps of posterior teeth. Type I and III cracks were predominant on the contacting surfaces of incisors, cusps of canines, and functional cusps of posterior teeth. Cracks originating from the dental-enamel junction and enamel tufts, crack deflections, and the initiation of new cracks within the enamel (internal cracks) were observed as bright areas. CLSM observations corroborated the SS-OCT findings. We found that crack pattern, tooth type, and the location of the crack on the tooth exhibited a strong correlation. We show that the use of 3D SS-OCT permits for the nondestructive 3D imaging and analysis of enamel crack behavior in whole human teeth in vitro. 3D SS-OCT possesses potential for use in clinical studies for the analysis of enamel crack behavior.

    (27872333) – as supplied by publisher]

    Bibliography

  • Effect of phytic acid etchant on resin-dentin bonding: Monomer penetration and stability of dentin collagen.
    .

    Effect of phytic acid etchant on resin-dentin bonding: Monomer penetration and stability of dentin collagen.

    J Prosthodont Res. 2016 Oct 21;:

    Authors: Kong K, Hiraishi N, Nassar M, Otsuki M, Yiu CK, Tagami J

    Abstract
    PURPOSE: Phytic acid (IP6) works well as an etchant in dentin bonding to remove the smear layer due to its acidity and chelating effect. This study compared the etching effect of IP6 with phosphoric acid (PA) and ethylenediaminetetraacetic acid (EDTA) on resin-dentin bond strength, micromorphology of the etched dentin surface and nanoleakage formation along resin-dentin interfaces and compared the protecting effect against collagen degradation.
    METHODS: Dentin disks and flat dentin surfaces were obtained from extracted human teeth. Specimens were etched with 35% PA (15s), 0.5M EDTA (30s) or 1% IP6 (30s). The surfaces and longitudinal sections of the etched dentin disks were observed using field emission scanning electron microscope (FE-SEM). An etch-and-rinse adhesive was used to create composite build up-specimens for microtensile bond strength (μTBS) testing and nanoleakage observation. To evaluate the effect on collagen degradation, demineralized bovine root dentin blocks were challenged with bacterial collagenase and then observed under light microscope.
    RESULTS: PA- and EDTA- treated groups showed significantly lower μTBS when compared to IP6-treated group. PA showed distinct nanoleakage and severe collagen degradation. Only slight nanoleakage was detected in IP6 group. IP6 showed better effect than EDTA in preventing collagen degradation induced by bacterial collagenase.
    CONCLUSIONS: IP6 effectively removed the smear layer and etched dentin, providing high bond strength values and causing minimal nanoleakage and slight collagen degradation.

    (27777071) – as supplied by publisher]

    Bibliography

  • Hesperidin interaction to collagen detected by physico-chemical techniques.

    Hesperidin interaction to collagen detected by physico-chemical techniques.

    Dent Mater. 2016 Oct 19;:

    Authors: Hiraishi N, Maruno T, Tochio N, Sono R, Otsuki M, Takatsuka T, Tagami J, Kobayashi Y

    Abstract
    OBJECTIVE: Dentin collagen can be modified by some plant-derived flavonoids to improve properties of dentin organic matrix. Hesperidin (HPN), a hesperetin-7-O-rutinoside flavonoid, has a potential of dentin modification for being based on evidence that a treatment with HPN may resist collagenase degradation and arrest demineralization of human dentin. In this study, biophysical and molecular-level information on the interaction of HPN and collagen was investigated.
    METHODS: HPN is extracted from citrus fruits. Sample collagenous solution was prepared using atelocollagen (ATCL) as a triple-helical peptide model. We have performed circular dichroism spectroscopic analysis, sedimentation velocity measurement by ultracentrifuge and saturation transfer difference measurement (STD) by NMR on HPN-collagen in solution state.
    RESULTS: The circular dichroism and sedimentation velocity measurement showed the evidence for the molecular interaction between ATCL and HPN, while HPN did not induce any conformational change of ATCL. The STD-NMR study further confirmed this interaction and suggested that HPN interacted with ATCL through its aromatic part, not through its disaccharide moiety.
    SIGNIFICANCE: These findings indicated that HPN is weakly bound to ATCL not causing structural modification of collagen. This interaction may contribute to the preservation of collagen by protecting from collagenase degradation.

    (27771138) – as supplied by publisher]

    Bibliography

  • Hesperidin interaction to collagen detected by physico-chemical techniques.

    Hesperidin interaction to collagen detected by physico-chemical techniques.

    Dent Mater. 2016 Oct 19;:

    Authors: Hiraishi N, Maruno T, Tochio N, Sono R, Otsuki M, Takatsuka T, Tagami J, Kobayashi Y

    Abstract
    OBJECTIVE: Dentin collagen can be modified by some plant-derived flavonoids to improve properties of dentin organic matrix. Hesperidin (HPN), a hesperetin-7-O-rutinoside flavonoid, has a potential of dentin modification for being based on evidence that a treatment with HPN may resist collagenase degradation and arrest demineralization of human dentin. In this study, biophysical and molecular-level information on the interaction of HPN and collagen was investigated.
    METHODS: HPN is extracted from citrus fruits. Sample collagenous solution was prepared using atelocollagen (ATCL) as a triple-helical peptide model. We have performed circular dichroism spectroscopic analysis, sedimentation velocity measurement by ultracentrifuge and saturation transfer difference measurement (STD) by NMR on HPN-collagen in solution state.
    RESULTS: The circular dichroism and sedimentation velocity measurement showed the evidence for the molecular interaction between ATCL and HPN, while HPN did not induce any conformational change of ATCL. The STD-NMR study further confirmed this interaction and suggested that HPN interacted with ATCL through its aromatic part, not through its disaccharide moiety.
    SIGNIFICANCE: These findings indicated that HPN is weakly bound to ATCL not causing structural modification of collagen. This interaction may contribute to the preservation of collagen by protecting from collagenase degradation.

    (27771138) – as supplied by publisher]

    Bibliography

  • A comparative study of the susceptibility of cut and uncut enamel to erosive demineralization.

    A comparative study of the susceptibility of cut and uncut enamel to erosive demineralization.

    Dent Mater J. 2016 Oct 22;

    Authors: Lin WT, Kitasako Y, Nakashima S, Tagami J

    Abstract
    This study aimed to evaluate the susceptibility of cut and uncut enamel surfaces to an erosive challenge and to examine the resultant characteristics/morphological changes. Ten extracted human incisors were used for preparation of enamel samples, and samples were immersed in citric acid. After 3 (total 3 min) and 6 cycles (total 6 min) of erosive challenges, surface loss (SL) and morphological changes were measured using scanning microscopy and FIB-TEM. Ca release (CA) and surface hardness (SH) were measured using a calcium-sensitive electrode and hardness tester respectively. Mean values of all measurements were statistically analyzed by using a t-test. Uncut enamel samples had significantly lower SL and greater SH than cut enamel (p<0.01). Cut enamel samples after 3 cycles showed higher CA compared with those from uncut enamel samples (p<0.05). Cut enamel was shown to be more susceptible to acidic dissolution and deeper acid penetration than uncut enamel after erosive demineralization.

    (27773896) – as supplied by publisher]

    Bibliography

  • A comparative study of the susceptibility of cut and uncut enamel to erosive demineralization.

    A comparative study of the susceptibility of cut and uncut enamel to erosive demineralization.

    Dent Mater J. 2016 Oct 22;

    Authors: Lin WT, Kitasako Y, Nakashima S, Tagami J

    Abstract
    This study aimed to evaluate the susceptibility of cut and uncut enamel surfaces to an erosive challenge and to examine the resultant characteristics/morphological changes. Ten extracted human incisors were used for preparation of enamel samples, and samples were immersed in citric acid. After 3 (total 3 min) and 6 cycles (total 6 min) of erosive challenges, surface loss (SL) and morphological changes were measured using scanning microscopy and FIB-TEM. Ca release (CA) and surface hardness (SH) were measured using a calcium-sensitive electrode and hardness tester respectively. Mean values of all measurements were statistically analyzed by using a t-test. Uncut enamel samples had significantly lower SL and greater SH than cut enamel (p<0.01). Cut enamel samples after 3 cycles showed higher CA compared with those from uncut enamel samples (p<0.05). Cut enamel was shown to be more susceptible to acidic dissolution and deeper acid penetration than uncut enamel after erosive demineralization.

    (27773896) – as supplied by publisher]

    Bibliography

  • Effects of C-factor on bond strength to floor and wall dentin.

    Effects of C-factor on bond strength to floor and wall dentin.

    Dent Mater J. 2016 Oct 01;

    Authors: Yoshikawa T, Sadr A, Tagami J

    Abstract
    This study evaluated the effect of C-factor on the bond strength of a resin composite to floor and wall dentin using two adhesive systems. Box-form cavities were prepared on human molars, following the walls of half of the cavities were removed to create flat dentin surfaces for bonding. Each specimen was then restored using one of two adhesives (Clearfil SE Bond or Clearfil tri-S Bond) and filled or built up using Z100 resin composite. After light-curing, the specimen was cut perpendicular to the bonded surface parallel to the floor or wall to obtain beams. The micro-tensile bond strength to the flat floor, flat wall, cavity floor, or cavity wall was determined. Resin composite bonded more strongly to the flat wall dentin than to the flat floor dentin, regardless of the adhesive system used. Bonding to the cavity wall was higher affected by C-factor than to the cavity floor.

    (27725368) – as supplied by publisher]

    Bibliography

  • Effects of C-factor on bond strength to floor and wall dentin.

    Effects of C-factor on bond strength to floor and wall dentin.

    Dent Mater J. 2016 Oct 01;

    Authors: Yoshikawa T, Sadr A, Tagami J

    Abstract
    This study evaluated the effect of C-factor on the bond strength of a resin composite to floor and wall dentin using two adhesive systems. Box-form cavities were prepared on human molars, following the walls of half of the cavities were removed to create flat dentin surfaces for bonding. Each specimen was then restored using one of two adhesives (Clearfil SE Bond or Clearfil tri-S Bond) and filled or built up using Z100 resin composite. After light-curing, the specimen was cut perpendicular to the bonded surface parallel to the floor or wall to obtain beams. The micro-tensile bond strength to the flat floor, flat wall, cavity floor, or cavity wall was determined. Resin composite bonded more strongly to the flat wall dentin than to the flat floor dentin, regardless of the adhesive system used. Bonding to the cavity wall was higher affected by C-factor than to the cavity floor.

    (27725368) – as supplied by publisher]

    Bibliography

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

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

    J Med Imaging (Bellingham). 2016 Jul;3(3):035507

    Authors: Ueno T, Shimada Y, Matin K, Zhou Y, Wada I, Sadr A, Sumi Y, Tagami J

    Abstract
    The aim of this study was to evaluate the signal intensity and signal attenuation of swept source optical coherence tomography (SS-OCT) for dental caries in relation to the variation of mineral density. SS-OCT observation was performed on the enamel and dentin artificial demineralization and on natural caries. The artificial caries model on enamel and dentin surfaces was created using Streptococcus mutans biofilms incubated in an oral biofilm reactor. The lesions were centrally cross sectioned and SS-OCT scans were obtained in two directions to construct a three-dimensional data set, from the lesion surface (sagittal scan) and parallel to the lesion surface (horizontal scan). The integrated signal up to [Formula: see text] in depth (IS200) and the attenuation coefficient ([Formula: see text]) of the enamel and dentin lesions were calculated from the SS-OCT signal in horizontal scans at five locations of lesion depth. The values were compared with the mineral density obtained from transverse microradiography. Both enamel and dentin demineralization showed significantly higher IS200 and [Formula: see text] than the sound tooth substrate from the sagittal scan. Enamel demineralization showed significantly higher IS200 than sound enamel, even with low levels of demineralization. In demineralized dentin, the [Formula: see text] from the horizontal scan consistently trended downward compared to the sound dentin.

    (27704033) – in process]

    Bibliography

  • White spot lesion remineralization by sugar-free chewing gum containing bio-available calcium and fluoride: A double-blind randomized controlled trial.
    .

    White spot lesion remineralization by sugar-free chewing gum containing bio-available calcium and fluoride: A double-blind randomized controlled trial.

    J Dent. 2016 Sep 14;

    Authors: Sugiura M, Kitasako Y, Sadr A, Shimada Y, Sumi Y, Tagami J

    Abstract
    OBJECTIVES: To assess the effect of chewing gum containing phosphoryl oligosaccharides of calcium (POs-Ca) and fluoride on white spot lesion (WSL) remineralization in comparison with POs-Ca or placebo (control) chewing gums, in double- blind, randomized, controlled trial.
    METHODS: Thirty-seven healthy subjects, who had at least one WSL, with an ICDAS score of 2 or 1, were recruited for this study. The subjects were randomly divided into three groups (control, POs-Ca, POs-Ca+F) and chewed two slabs of each gum three times every day for 3 months. WSLs were assessed using ICDAS criteria and optical boundary depth (BD) by optical coherence tomography (OCT) system at a monthly recall. Data were analyzed by Wilcoxon rank-sum test and Wilcoxon signed rank test with Bonferroni corrections at 0.05 significance level.
    RESULTS: Visual score changes from ICDAS score 2 to score 1 over the course of the study were observed; control (30%), POs-Ca (48%) and POs-Ca+F (45%). Unlike the control gum, chewing POs-Ca and POs-Ca+F gums resulted in significant changes in the mean value of BD over the 3 months course of the study (p<0.05). There was a significant difference in mean value of BD after first month between POs-Ca+ F and control groups (p<0.05).
    CONCLUSIONS: This study highlighted the importance of calcium and fluoride ion bioavailability in the reinforcement of demineralized enamel lesions by chewing gums. Furthermore, adding fluoride to POs-Ca might speed up the remineralization progress on natural WSL.

    (27639827) – as supplied by publisher]

    Bibliography

  • White spot lesion remineralization by sugar-free chewing gum containing bio-available calcium and fluoride: A double-blind randomized controlled trial.
    .

    White spot lesion remineralization by sugar-free chewing gum containing bio-available calcium and fluoride: A double-blind randomized controlled trial.

    J Dent. 2016 Sep 14;

    Authors: Sugiura M, Kitasako Y, Sadr A, Shimada Y, Sumi Y, Tagami J

    Abstract
    OBJECTIVES: To assess the effect of chewing gum containing phosphoryl oligosaccharides of calcium (POs-Ca) and fluoride on white spot lesion (WSL) remineralization in comparison with POs-Ca or placebo (control) chewing gums, in double- blind, randomized, controlled trial.
    METHODS: Thirty-seven healthy subjects, who had at least one WSL, with an ICDAS score of 2 or 1, were recruited for this study. The subjects were randomly divided into three groups (control, POs-Ca, POs-Ca+F) and chewed two slabs of each gum three times every day for 3 months. WSLs were assessed using ICDAS criteria and optical boundary depth (BD) by optical coherence tomography (OCT) system at a monthly recall. Data were analyzed by Wilcoxon rank-sum test and Wilcoxon signed rank test with Bonferroni corrections at 0.05 significance level.
    RESULTS: Visual score changes from ICDAS score 2 to score 1 over the course of the study were observed; control (30%), POs-Ca (48%) and POs-Ca+F (45%). Unlike the control gum, chewing POs-Ca and POs-Ca+F gums resulted in significant changes in the mean value of BD over the 3 months course of the study (p<0.05). There was a significant difference in mean value of BD after first month between POs-Ca+ F and control groups (p<0.05).
    CONCLUSIONS: This study highlighted the importance of calcium and fluoride ion bioavailability in the reinforcement of demineralized enamel lesions by chewing gums. Furthermore, adding fluoride to POs-Ca might speed up the remineralization progress on natural WSL.

    (27639827) – as supplied by publisher]

    Bibliography

  • Effects of zinc fluoride on inhibiting dentin demineralization and collagen degradation in vitro: A comparison of various topical fluoride agents.

    Effects of zinc fluoride on inhibiting dentin demineralization and collagen degradation in vitro: A comparison of various topical fluoride agents.

    Dent Mater J. 2016 Aug 20;

    Authors: Thanatvarakorn O, Islam MS, Nakashima S, Sadr A, Nikaido T, Tagami J

    Abstract
    Root caries is developed because of demineralization followed by enzymatic collagen degradation. This in vitro study aimed to examine the inhibitory efficacy of ZnF2 on dentin demineralization and collagen degradation. Bovine dentin specimens were treated either with ZnF2 or HCl-acidified ZnF2 (ZnF2/HCl) and then demineralized. Anti-demineralization efficacy was assessed by TMR as mineral loss (ΔZ). The efficacy was compared with silver diammine fluoride (SDF), KF, and acidulated phosphate fluoride (APF). For evaluating anti-collagen degradation, EDTA-demineralized dentin specimens were treated by one of four fluoride agents [SDF, APF, ZnF2/HCl, NaF] followed by collagenase challenge. The eroded depth of collagen layer in the lesion was assessed using optical microscope. ΔZ of SDF, KF, ZnF2/HCl, and APF were significantly lower compared with ZnF2 and Control (no treatment). Regarding anti-collagen degradation, SDF and ZnF2/HCl demonstrated a significant difference in the eroded depth compared with Control. Although SDF possessed higher efficacy, ZnF2/HCl might be beneficial as a staining-free agent.

    (27546855) – as supplied by publisher]

    Bibliography

  • Effects of zinc fluoride on inhibiting dentin demineralization and collagen degradation in vitro: A comparison of various topical fluoride agents.

    Effects of zinc fluoride on inhibiting dentin demineralization and collagen degradation in vitro: A comparison of various topical fluoride agents.

    Dent Mater J. 2016 Aug 20;

    Authors: Thanatvarakorn O, Islam MS, Nakashima S, Sadr A, Nikaido T, Tagami J

    Abstract
    Root caries is developed because of demineralization followed by enzymatic collagen degradation. This in vitro study aimed to examine the inhibitory efficacy of ZnF2 on dentin demineralization and collagen degradation. Bovine dentin specimens were treated either with ZnF2 or HCl-acidified ZnF2 (ZnF2/HCl) and then demineralized. Anti-demineralization efficacy was assessed by TMR as mineral loss (ΔZ). The efficacy was compared with silver diammine fluoride (SDF), KF, and acidulated phosphate fluoride (APF). For evaluating anti-collagen degradation, EDTA-demineralized dentin specimens were treated by one of four fluoride agents [SDF, APF, ZnF2/HCl, NaF] followed by collagenase challenge. The eroded depth of collagen layer in the lesion was assessed using optical microscope. ΔZ of SDF, KF, ZnF2/HCl, and APF were significantly lower compared with ZnF2 and Control (no treatment). Regarding anti-collagen degradation, SDF and ZnF2/HCl demonstrated a significant difference in the eroded depth compared with Control. Although SDF possessed higher efficacy, ZnF2/HCl might be beneficial as a staining-free agent.

    (27546855) – as supplied by publisher]

    Bibliography

  • Effect of enamel margin configuration on color change of resin composite restoration.

    Effect of enamel margin configuration on color change of resin composite restoration.

    Dent Mater J. 2016;35(4):675-83

    Authors: Aida A, Nakajima M, Seki N, Kano Y, Foxton RM, Tagami J

    Abstract
    This study aimed to investigate the effect of enamel margin configuration on color change of resin composite restoration. Enamel disks of 1.0 mm-thick were sliced from sixty bovine anterior teeth and divided into three groups by margin configuration (non-bevel, 45-degree bevel and 45-degree reverse-bevel). The color measurements (L*C*h* values) at the restored bovine enamel disk with resin composite (Estelite Asteria, Estelite Pro, Kalore, Clearfil Majesty) were performed using a digital camera with CIE XYZ color gamut (RC500). All the resin composite restorations with non-beveled and beveled cavities significantly increased L* values compared with the control composite disks (p<0.05). The bevel preparation increased L* values toward the enamel-composite border with gentle inclination, while the reverse-bevel preparation was significantly lower L* values at the enamel-composite border than the non-bevel preparation (p<0.05). Enamel margin configuration affected color shifting of resin composite restoration and color adjustment of the border.

    (27477235) – in process]

    Bibliography

  • Effects of brushing timing after erosive challenge on enamel loss in situ: White light interferometer and nanoindentation study.

    Effects of brushing timing after erosive challenge on enamel loss in situ: White light interferometer and nanoindentation study.

    Dent Mater J. 2016;35(4):613-20

    Authors: Tsuda Y, Kitasako Y, Sadr A, Nakashima S, Tagami J

    Abstract
    This in situ study aimed to evaluate effects of waiting periods after erosive challenge before toothbrushing on enamel abrasion and nanoindentation hardness. Ten subjects wore intraoral appliances each with a set of 4 bovine enamel blocks. The enamel blocks were subjected to 2 cycles a day for 3 days as follows; intraoral exposure to form acquired pellicle and extraoral erosion followed by either 0, 3, 30 or 60 min intraoral exposure and then brushing, which was performed using an automatic brushing machine. Abrasive loss was assessed by white light interferometry. Nanoindentation was performed to calculate relative hardness. Abrasion and relative hardness were statistically analyzed by ANOVA. Abrasive loss was significantly less in groups exposed to saliva compared with 0 min (p<0.05); there was no significant difference between 30 and 60 min (p>0.05). Relative hardness was statistically higher after intraoral exposure, but no differences existed among any intraoral exposure periods (p>0.05).

    (27477227) – in process]

    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

  • 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]

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