Journal of Oral Science
Online ISSN : 1880-4926
Print ISSN : 1343-4934
ISSN-L : 1343-4934
Volume 60, Issue 3
September
Displaying 1-20 of 20 articles from this issue
Review
  • Yaeko Hara, Hiroshi Shiratsuchi, Takaaki Tamagawa, Ryosuke Koshi, Chih ...
    2018 Volume 60 Issue 3 Pages 321-328
    Published: 2018
    Released on J-STAGE: September 23, 2018
    JOURNAL FREE ACCESS

    Recently, reports regarding a foreign body in the maxillary sinus have considerably increased, with the majority being iatrogenic cases resulting from dental treatment. This study involves an extensive review of the Japanese literature, including 112 papers from 1978 to 2017. These papers documented total 407 cases of a foreign body in the maxillary sinus. Among the 392 cases for which treatment details were available, the Caldwell-Luc approach was used for 216, the alveolar approach for 116, extraction using nasal endoscopy for 15, and extraction using oral endoscopy for eight. Spontaneous passage occurred in 19 cases, follow-up with medication was used in 17, and “other” was noted in one. This study determined that surgical removal remains the most common method for treating both tooth roots and other foreign bodies and that the Caldwell-Luc approach is used in majority of the surgeries. No marked differences were noted among the removal methods used in relation to the foreign body type.

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Original
  • Jun Lee, Chisato Yamate, Masato Taira, Masamichi Shinoda, Kentaro Urat ...
    2018 Volume 60 Issue 3 Pages 329-335
    Published: 2018
    Released on J-STAGE: September 23, 2018
    Advance online publication: May 24, 2018
    JOURNAL FREE ACCESS

    Prefrontal cortex activity is modulated by flavor and taste stimuli and changes during swallowing. We hypothesized that changes in the modulation of prefrontal cortex activity by flavor and taste were associated with swallowing movement and evaluated brain activity during swallowing in patients with dysphagia. To evaluate prefrontal cortex activity in dysphagia patients during swallowing, change in oxidized hemoglobin (z-score) was measured with near-infrared spectroscopy while dysphagia patients and healthy controls swallowed sweetened/unsweetened and flavored/unflavored jelly. Total z-scores were positive during swallowing of flavored/unsweetened jelly and negative during swallowing of unflavored/sweetened jelly in controls but negative during swallowing of sweetened/unsweetened and flavored/unflavored jelly in dysphagia patients. These findings suggest that taste and flavor during food swallowing are associated with positive and negative z-scores, respectively. Change in negative and positive z-scores may be useful in evaluating brain activity of dysphagia patients during swallowing of sweetened and unsweetened food.

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  • Moeko Kato, Yasuhiro Namura, Takayuki Yoneyama, Noriyoshi Shimizu
    2018 Volume 60 Issue 3 Pages 336-343
    Published: 2018
    Released on J-STAGE: September 23, 2018
    Advance online publication: May 31, 2018
    JOURNAL FREE ACCESS

    This study investigated the effect of the vertical position of the canine on changes in the frictional/orthodontic (F/O) force ratio of nickel-titanium (Ni-Ti) archwires during the initial levelling phase of orthodontic treatment. Frictional and orthodontic forces were measured by using low-friction brackets and Ni-Ti archwires with three different cross-sectional sizes and force types. To simulate canine malocclusion (first premolar extraction case), the upper right canine was displaced gingivally by 1 to 3 mm and the inter-bracket distance between the upper right lateral incisor and second premolar was set at 15 mm or 20 mm. A three-point bending test was performed to measure the orthodontic force of each Ni-Ti archwire. Frictional forces were measured with a universal testing machine and dental arch models by pulling parallel to the end of the archwire at a crosshead speed of 0.5 mm/min. F/O force ratio was calculated and analysed statistically. At a displacement of 3 mm, few archwires had F/O force ratios of less than 1.0, at which orthodontic force overcame frictional force, thus ensuring extrusion of the canine. For effective tooth movement, orthodontists should use Ni-Ti archwires with an F/O force ratio of less than 1.0.

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  • Erhan Dursun, Güliz N. Güncü, Ceyda K. Dursun, Arlin Kiremitçi, Erdem ...
    2018 Volume 60 Issue 3 Pages 344-351
    Published: 2018
    Released on J-STAGE: September 23, 2018
    Advance online publication: August 25, 2018
    JOURNAL FREE ACCESS

    The aim of this study was to evaluate the clinical root coverage results of subepithelial connective tissue grafts (SCTG) performed on teeth with gingival recessions and non-carious cervical lesions (NCCLs) that were restored with cervical fillings and compare the results of two different filling materials: resin-modified glass ionomer (RMGIC) and nano-ionomer cements (NIC). A total of 54 teeth with Miller Class I gingival recessions with or without NCCLs in 36 patients (28 females, 8 males) were treated with SCTGs. Cervical lesions were randomly treated with RMGIC or NIC restorations. Periodontal clinical parameters, height of gingival recession (HGR), width of gingival recession (WGR), height of keratinized tissue, and dentin sensitivity were measured at baseline and 3, 6, and 12 months postoperatively. HGR and WGR values were statistically significantly reduced at all time points when compared to baseline values in all groups. There were no statistically significant differences between the groups in any clinical periodontal parameter (P > 0.05). The percentage of root coverage at 12 months was 89.5%, 90.1%, and 96.2% in the RMGIC, NIC, and control groups, respectively. Successful root coverage with connective tissue grafts may be achieved on teeth restored with RMGIC or NIC cervical fillings.

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  • Hironori Mori, Kazunori Hamamura, Shoyoku Yo, Kosuke Hamajima, Kenji O ...
    2018 Volume 60 Issue 3 Pages 352-359
    Published: 2018
    Released on J-STAGE: September 23, 2018
    Advance online publication: July 09, 2018
    JOURNAL FREE ACCESS

    Dental pulp is known to play crucial roles in homeostasis of teeth and periodontal tissue. Although resorption of bone around the roots of nonvital teeth is occasionally observed in clinical practice, little is known about the role of dental pulp in osteoclastogenesis. Here we evaluated the effects of conditioned medium (CM) from rat dental pulp on osteoclastogenesis. It was found that the CM reduced the number of tartrate-resistant acid phosphatase (TRAP)-positive multinucleated osteoclasts, but did not alter the mRNA levels of nuclear factor of activated T-cells, cytoplasmic 1 and TRAP. To further understand the mechanism behind these results, we evaluated the effects of CM on osteoclast precursors and found that the CM removed cell processes, resulting in a significant reduction in the number of attached cells and an increase in the number of freely floating cells. Furthermore, the CM suppressed the mRNA levels of focal adhesion kinase and paxillin, which are involved in cell adhesiveness and spreading. Collectively, the present results show that CM from dental pulp serves as an inhibitor of osteoclastogenesis by reducing the number and adhesiveness of osteoclast precursors, suggesting novel therapeutic applicability for osteoporosis.

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  • Serina Taguchi, Futoshi Komine, Kei Kubochi, Ryosuke Fushiki, Fumiaki ...
    2018 Volume 60 Issue 3 Pages 360-366
    Published: 2018
    Released on J-STAGE: September 23, 2018
    Advance online publication: August 25, 2018
    JOURNAL FREE ACCESS

    This study examined the effect of silane and phosphate functional monomer on bond strengths between a resin-based luting agent joined to a lithium disilicate ceramic (IPS e.max) and silica (quartz) materials. The e.max and quartz specimens were assigned to 6 groups with different priming/bonding agents, namely, Clearfil Porcelain Bond Activator, Clearfil Photo Bond, Clearfil Photo Bond Universal with Clearfil Porcelain Bond Activator, Clearfil Photo Bond Catalyst with Clearfil Porcelain Bond Activator, Clearfil Photo Bond with Clearfil Porcelain Bond Activator, and unprimed. The corresponding specimens were bonded by using a resin-based luting agent (Panavia V5). Shear bond strengths were determined before and after 5,000 thermocycles. For both the e.max and quartz specimens, the Clearfil Photo Bond Universal with Clearfil Porcelain Bond Activator group had the highest pre- and post-thermocycling bond strength values. Combined use of silane in the acidic environment of a phosphate functional monomer and initiators enhances bond strength of a resin-based luting agent to e.max ceramic and quartz materials.

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  • Ryosuke Murayama, Yuko Nagura, Kabun Yamauchi, Nobuyuki Moritake, Masa ...
    2018 Volume 60 Issue 3 Pages 367-373
    Published: 2018
    Released on J-STAGE: September 23, 2018
    Advance online publication: July 09, 2018
    JOURNAL FREE ACCESS

    We used optical coherence tomography to examine the effect of a coating material containing surface reaction-type pre-reacted glass-ionomer (S-PRG) filler on primary enamel demineralization in 18 extracted human primary teeth. The pulp was removed, and each tooth was ultrasonically cleaned with distilled water. Six teeth were treated with 0.1-M lactic acid buffer solution (De group). In the second group (n = 6), a thin film of coating material was applied before demineralization (PRG group). A third group (Control group; n = 6) was maintained in artificial saliva. Using optical coherence tomography, we measured peak signal intensity (dB) and width at 1/e2 (µm) at predetermined locations on the enamel surface and calculated integrated values. All data were analyzed with ANOVA and the Tukey-Kramer test (α = 0.05). Although changes in integrated values differed between groups, there was a small but significant increase in the Control group and a small but significant decrease in the De group. In the PRG group, integrated values were significantly higher at 7 days after the start of the experiment and significantly increased thereafter. Our findings indicate that a coating material containing S-PRG fillers may prevent primary enamel demineralization.

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  • Miho Obayashi-Ishii, Satsuki Saito, Daisuke Omagari, Masatake Asano, T ...
    2018 Volume 60 Issue 3 Pages 374-380
    Published: 2018
    Released on J-STAGE: September 23, 2018
    Advance online publication: August 25, 2018
    JOURNAL FREE ACCESS

    Magnetic attachments are commonly used for overdentures. The deleterious effects of exposure to magnetic flux on human health have not been substantiated so far; nevertheless, there is a need to understand the extent of magnetic field exposure in the oral area resulting from the use of magnetic attachments. The purpose of this study was to investigate the influence of a magnetic field on oral squamous cell carcinoma. Tumor cells cultured on a magnetic plate were compared with those not cultured on a magnetic plate (controls). The cells were seeded at a density of 1 × 105 cells/well and cultured for 6 days. The influence of the magnetic field on cytokine production was examined by cytokine array analysis. Secretion of platelet-derived growth factor-AA (PDGF-AA) was measured by enzyme-linked immunosorbent assay and Western blotting. The expression of PDGF-AA messenger RNA was examined by real-time polymerase chain reaction, whereas nuclear factor-kappa B activity was measured by luciferase assay. The results indicated that the magnetic field inhibited the secretion of PDGF-AA, thereby inhibiting PDGF-AA-induced expression, thus reducing the risk of cancer recurrence.

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  • Indre Graunaite, Greta Lodiene, Odeta Arandarcikaite, Audrius Pukalska ...
    2018 Volume 60 Issue 3 Pages 381-387
    Published: 2018
    Released on J-STAGE: September 23, 2018
    Advance online publication: August 12, 2018
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    This in vitro study aimed to detect leaching components from an epoxy resin- and a methacrylate-based endodontic sealer and correlate them to cytotoxicity induced by material extracts for up to 36 weeks. We qualitatively determined the substances released by aged AH Plus and RealSeal SE specimens at seven intervals between 0 and 36 weeks. Quantification was performed by ultra-performance liquid chromatography/mass spectrometry (UPLC/MS). We determined the viability of murine macrophage J774 cells after 24 h exposure to material extracts, at each interval, using a fluorescence staining/microscopy method. The leachables detected were 1-adamantylamine and bisphenol A diglycidyl ether from AH Plus and N-(p-tolyl) diethanolamine and caprolactone-2-(methacryloyloxy) ethyl ester from RealSeal SE. The largest UPLC/MS chromatogram peak areas of the leachables were detected within 72 h. Induction of cytotoxicity after exposure to AH Plus and RealSeal SE extracts coincided with leachant detected within the first 72 and 24 h, respectively. The clinical impact of the cytotoxicity due to resin-based endodontic sealers is unknown.

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  • Keisuke Noda, Mizuho Yamazaki, Yasunobu Iwai, Sari Matsui, Ayako Kato, ...
    2018 Volume 60 Issue 3 Pages 388-398
    Published: 2018
    Released on J-STAGE: September 23, 2018
    Advance online publication: August 30, 2018
    JOURNAL FREE ACCESS

    Amelotin (AMTN) is an enamel protein expressed in maturation-stage ameloblasts and junctional epithelium. To clarify the transcriptional regulation of the AMTN gene by interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α), we conducted real-time PCR, Western blotting, transient transfection analyses with luciferase constructs including various lengths of the mouse AMTN gene promoter, and gel shift and chromatin immunoprecipitation assays using mouse gingival epithelial GE1 cells. The levels of AMTN mRNA and protein in GE1 cells were increased after 6 h of stimulation with IL-1β (1 ng/mL) and TNF-α (10 ng/mL). IL-1β and TNF-α induced luciferase activities of the constructs between −116AMTN and −705AMTN including the mouse AMTN gene promoter. Transcriptional activation by IL-1β and TNF-α was partially inhibited in −460AMTN including 3-bp mutations in the CCAAT-enhancer-binding protein 1 (C/EBP1), C/EBP2 and Yin Yang 1 (YY1) elements. Transcriptional activities induced by IL-1β and TNF-α were inhibited by tyrosine kinase, MEK1/2 and PI3-kinase inhibitors. Results of ChIP assays showed that IL-1β and TNF-α increased C/EBPβ and YY1 binding to the C/EBP1, C/EBP2 and YY1 elements. These results demonstrate that IL-1β and TNF-α increase AMTN gene transcription via the C/EBP1, C/EBP2 and YY1 elements in the mouse AMTN gene promoter.

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  • Asako Suzuki, Masayasu Ito, Yasuhiko Kawai
    2018 Volume 60 Issue 3 Pages 399-404
    Published: 2018
    Released on J-STAGE: September 23, 2018
    Advance online publication: August 25, 2018
    JOURNAL FREE ACCESS

    Clear magnetic resonance imaging (MRI) is required to diagnose tongue cancer. However, the absence of occlusal support may cause tongue movements which are known to introduce artifacts on the MR image. This pilot study compared the manifest of artifacts from the tongue at rest and during motion using luminance standard deviation (LSD) to quantify the artifacts, in dentulous subjects. Participants were ten dentulous participants (5 males, 5 females; age 31.50 ± 8.38 years) with occlusal support. MRI was conducted with the tongue at rest and during lateral movement. The LSD was measured in the regions of interest (ROI) in the axial and sagittal planes. Tongue movement evoked unclear MR images, compared with the images taken at rest. Statistical analysis revealed that the LSD significantly differed between the tongue at rest and in motion in the axial (P = 0.004) and sagittal planes (ROI-A: P = 0.002, ROI-P: P = 0.006). These findings suggest that tongue movement introduces motion artifact and the LSD responds quantitatively to the magnitude of artifacts. Future studies will evaluate whether a prosthetic device used to provide occlusive support can decrease these artifacts when analyzed using LSD.

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  • Takahiro Mitsui, Masahiko Saito, Ryô Harasawa
    2018 Volume 60 Issue 3 Pages 405-410
    Published: 2018
    Released on J-STAGE: September 23, 2018
    Advance online publication: August 12, 2018
    JOURNAL FREE ACCESS

    Dietary nitrate has several beneficial effects, including blood pressure reduction and improved oxygen consumption efficiency, but in order to do so it must first be reduced to nitrite by oral bacteria. Veillonella spp., a strictly anaerobic group, are the most prevalent nitrate-reducing bacteria in the oral cavity. In response to some early studies that have hinted at inter- and intra-individual variation in salivary nitrate-nitrite conversion capacity, the purpose of the present study was to investigate the incidence of and variation in the Veillonella species V. atypica, V. dispar, and V. rogosae by direct PCR and to assess salivary nitrate-nitrite conversion capacity and its reproducibility after dietary nitrate consumption in 24 elderly individuals. V. atypica, V. dispar, and V. rogosae were detected in 10 (41.7%), 24 (100%), and 14 (58.3%) participants, respectively. The coefficients of correlation between the first and second experiments on increased nitrate/nitrite were 0.637 and 0.583, respectively, both of which were statistically significant (P < 0.01). In both experiments, 6 participants produced relatively low levels of nitrite (<0.5 mM Δ nitrite) while 7 produced relatively high levels (>1.0 mM Δ nitrite). The data suggested that V. dispar was the most prevalent species, being present even in individuals producing low levels of salivary nitrite.

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  • Hiroshi Kudo, Osamu Takeichi, Kosuke Makino, Keisuke Hatori, Bunnai Og ...
    2018 Volume 60 Issue 3 Pages 411-417
    Published: 2018
    Released on J-STAGE: September 23, 2018
    Advance online publication: August 12, 2018
    JOURNAL FREE ACCESS

    Silent information regulator 2 homolog 1 (SIRT1) inhibits oxidative injury and has anti-inflammatory effects. SIRT1 may be involved in healing of periapical periodontitis; however, SIRT1 expression in periapical periodontitis lesions has not been investigated. This study evaluated SIRT1 expression and a marker of oxidative stress—8-hydroxy-2’-deoxyguanosine (8-OHdG)—in periapical granulomas. First, we used real-time polymerase chain reaction to determine whether U-937 monocytes express SIRT1. U-937 cells treated with the SIRT1 activator resveratrol exhibited the highest SIRT1 mRNA level after 6-h incubation. By contrast, treating cells with the SIRT1 inhibitor sirtinol returned SIRT1 expression level to that of the control. In addition, immunocytochemical analysis using cytospin specimens showed that U-937 cells co-expressed SIRT1 and Ki-67. Dual-color immunofluorescence imaging showed that round cells in periapical granulomas co-expressed SIRT1 and 8-OHdG; however, neither was expressed in healthy gingival tissues. The number of 8-OHdG-expressing cells was significantly greater than the number of SIRT1-expressing cells. Our findings suggest that macrophages express SIRT1 and that wound healing in periapical granulomas is enhanced by a SIRT1-mediated reduction in the level of oxidative stress.

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  • Masaki Tsubokawa, Akira Aoki, Sho Kakizaki, Yoichi Taniguchi, Kenichir ...
    2018 Volume 60 Issue 3 Pages 418-427
    Published: 2018
    Released on J-STAGE: September 23, 2018
    Advance online publication: May 24, 2018
    JOURNAL FREE ACCESS

    This study evaluated the effectiveness of swept-source optical coherence tomography (ss-OCT) for detecting calculus and root cementum during periodontal therapy. Optical coherence tomography (OCT) images were taken before and after removal of subgingival calculus from extracted teeth and compared with non-decalcified histological sections. Porcine gingival sheets of various thicknesses were applied to the root surfaces of extracted teeth with calculus and OCT images were taken. OCT images were also taken before and after scaling and root planing (SRP) in human patients. In vitro, calculus was clearly detected as a white-gray amorphous structure on the root surface, which disappeared after removal. Cementum was identified as a thin, dark-gray layer. The calculus could not be clearly observed when soft tissues were present on the root surface. Clinically, supragingival calculus and cementum could be detected clearly with OCT, and subgingival calculus in the buccal cervical area of the anterior and premolar teeth was identified, which disappeared after SRP. Digital processing of the original OCT images was useful for clarifying the calculus. In conclusion, ss-OCT showed potential as a periodontal diagnostic tool for detecting cementum and subgingival calculus, although the practical applications of subgingival imaging remain limited.

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  • Kallapat Tansriratanawong, Pawinee Wongwan, Hiroshi Ishikawa, Taka Nak ...
    2018 Volume 60 Issue 3 Pages 428-437
    Published: 2018
    Released on J-STAGE: September 23, 2018
    Advance online publication: August 12, 2018
    JOURNAL FREE ACCESS

    Calcium hydrogen phosphate with a hydroxyapatite-like surface (CHP-HA) is a novel synthesized compound designed to overcome the limitations of bioactive ceramics. It was originally applied as nano-sized HA strips covering core plates to enhance the degree of interfacial attachment. The objective of the present study was to examine the cellular attachment, proliferation, and osteogenic differentiation of periodontal ligament stem cells (PDLSCs) on a CHP-HA substrate in comparison with conventional nanohydroxyapatite (NanoHA). The PDLSCs were cultivated with either CHP-HA or NanoHA for cellular attachment, proliferation, and osteogenic differentiation assay. Osteogenic differentiation was examined using quantitative polymerase chain reaction and immunofluorescence after confirmation by Alizarin red staining. We found that between 14 and 21 days, CHP-HA exhibited a well-organized matrix distribution, a high degree of cell proliferation, and a high level of Alizarin red staining in comparison to NanoHA. Expression of all the osteogenic markers examined was increased significantly relative to NanoHA at 14 days, but no significant differences in some osteogenic genes were found at 21 days. Immunofluorescence revealed stronger staining in the CHP-HA group. In conclusion, PDLSCs cultivated with this novel CHP-HA show enhanced cellular responses. We propose that CHP-HA may be a promising alternative biomaterial for periodontal tissue engineering.

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  • Ji Hyun Yoo, Seung-Min Lee, Moon Kyoung Bae, Dong Joon Lee, Ching-Chan ...
    2018 Volume 60 Issue 3 Pages 438-445
    Published: 2018
    Released on J-STAGE: September 23, 2018
    Advance online publication: May 24, 2018
    JOURNAL FREE ACCESS

    The purpose of this study was to evaluate the effects of orthodontic forces (OF) on the proliferation and differentiation of human periodontal ligament stem cells (hPDLSCs). The experimental sample consisted of 6 premolars extracted from 2 patients. After application of OF for 1 month, the hPDLSCs were separated from the primary cultured PDL cells using magnetic-activated cell sorting. The cell proliferation rate was assessed using a 3-[45-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide assay. The hPDLSCs were cultured in osteogenic medium, and the osteogenic differentiation was analyzed on day 7 and 14 using alkaline phosphatase staining and reverse transcription polymerase chain reaction analyses. The gene expression level of osteogenic markers and angiogenic markers were measured and normalized. The results showed that the application of OF increased the proliferation rates, the expression of osteogenic factors, and the expression of angiogenic factors of hPDLSCs. These findings suggest that OF can serve as a potent positive modulator of proliferation and osteogenic differentiation of hPDLSCs.

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  • Seyda Ersahan, Fidan A. Sabuncuoglu
    2018 Volume 60 Issue 3 Pages 446-452
    Published: 2018
    Released on J-STAGE: September 23, 2018
    JOURNAL FREE ACCESS

    We aimed to assess the relationship between age, pulpal blood flow (PBF), and orthodontic treatment outcomes. Decreased blood supply to pulp cells commonly occurs with age and can change the response of pulp to orthodontic tooth movement. This study was conducted in 28 human subjects divided into 2 groups according to age. A laser Doppler flowmeter was used to record blood flow to the teeth prior to and during the course of orthodontic treatment (days 1, 3, and 7; week 3; and month 1). Data were analyzed using Wilcoxon signed-rank and Mann-Whitney U tests. Mean PBF values were significantly higher in the young group compared to the old group at all time points (P < 0.001). The decreased PBF in response to tooth movement was more severe in the old group and was also of longer duration. Pulp in younger patients had significantly higher blood flow values compared to that in older patients at baseline and throughout the course of the study.

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  • Takanobu Yamamoto, Akira Hasuike, Ryosuke Koshi, Yasumasa Ozawa, Manam ...
    2018 Volume 60 Issue 3 Pages 453-459
    Published: 2018
    Released on J-STAGE: September 23, 2018
    Advance online publication: August 12, 2018
    JOURNAL FREE ACCESS

    We used radiological and histological analyses to evaluate the effects of mechanical barrier permeability in a rat model of calvarial guided bone augmentation (GBA). The calvaria of 20 rats were exposed, and one of four types of plastic caps (an occlusive cylindrical plastic cap; a plastic cap with no top; a plastic cap with three holes; and a plastic cap with four holes) was randomly placed on both sides. Newly generated bone in the plastic caps was evaluated with micro-computed tomography (micro-CT) and histological analysis. Micro-CT volumetric analysis and decalcified hematoxylin and eosin-stained sections showed that GBA barrier permeability was inversely associated with the quantity of augmented bone obtained. Masson’s trichrome staining showed that collagen in newly generated bony tissue was more mature in plastic caps with three holes than in those with more-permeable or more-occlusive barriers. Bone augmentation was inhibited in specimens exhibiting invasion of soft tissue through penetrating holes, and barrier permeability was associated with the quantity of augmented bone developed. In conclusion, moderate barrier permeability is optimal for development of mature augmented bone.

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  • Serhat Köken, Jelena Juloski, Roberto Sorrentino, Simone Grandini, Mar ...
    2018 Volume 60 Issue 3 Pages 460-468
    Published: 2018
    Released on J-STAGE: September 23, 2018
    Advance online publication: April 25, 2018
    JOURNAL FREE ACCESS

    We investigated the effect of cervical marginal relocation (CMR) on marginal sealing with two different viscosity resin composites, before adhesive cementation of composite computer-aided design/computer-assisted manufacture mesio-occluso-distal (MOD) overlays. Standardized MOD cavities prepared in 39 human molars were randomly assigned to three groups. The proximal margins on the mesial side were located 1 mm below the cementoenamel junction. On the distal side of the tooth, the margins were located 1 mm above the cementoenamel junction. In Groups 1 and 2, mesial proximal boxes were elevated with a hybrid composite (GC Essentia MD) and a flowable composite (GC G-ænial Universal Flo), respectively. CMR was not performed in Group 3. The overlays were adhesively cemented, and interfacial leakage was quantified by scoring the depth of silver nitrate penetration along the adhesive interfaces. Leakage score at the dentin-CMR composite interface did not significantly differ between the two tested composites but was significantly lower for Group 3. In all groups, scores were significantly higher at the dentin interface than at the enamel interface. These results indicate that the performance of flowable and microhybrid resin composites, as indicated by marginal sealing ability, is comparable for CMR.

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Case Report
  • Jun Kurihara, Shiro Mori, Mariko Oikawa, Hiroyuki Kumamoto, Tetsu Taka ...
    2018 Volume 60 Issue 3 Pages 469-472
    Published: 2018
    Released on J-STAGE: September 23, 2018
    Advance online publication: April 25, 2018
    JOURNAL FREE ACCESS

    A clear cell variant of calcifying epithelial odontogenic tumor (CCEOT) affecting an extraosseous site is described. A 60-year-old male patient presented with gingival swelling on the lingual side of the anterior mandible. The results of biopsy suggested clear cell odontogenic carcinoma, and marginal resection of the mandible was performed. The resected specimen was composed of eosinophilic and clear cells with deposits of amyloid-like material. The clear cells exhibited granules that were positive for PAS. There was no calcification in the resected lesion. Based on these features, the conclusive diagnosis was peripheral CCEOT without calcification. No signs of recurrence were evident after 3 years of follow-up.

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