Journal of Oral Science
Online ISSN : 1880-4926
Print ISSN : 1343-4934
ISSN-L : 1343-4934
Current issue
October
Showing 1-24 articles out of 24 articles from the selected issue
Review
  • Futoshi Komine, Junichi Honda, Kosuke Kusaba, Kei Kubochi, Hiroki Taka ...
    Type: review-article
    2020 Volume 62 Issue 4 Pages 353-355
    Published: 2020
    Released: September 26, 2020
    [Advance publication] Released: August 01, 2020
    JOURNALS FREE ACCESS

    Computer-aided design/computer-aided manufacturing (CAD/CAM) restorative materials have been widely used owing to a number of advantages, including stable quality of the materials, lower costs, and time-saving factors. Resin-based CAD/CAM materials for definitive restorations are classified into two groups: dispersed nanoparticle-filled composite resin and polymer-infiltrated-ceramic-network materials. Resin-based CAD/CAM materials have been applied to single crown restorations as a monolithic structure for the posterior region. In addition, resin-based CAD/CAM restorations have been applied recently for the anterior area. This literature review summarizes clinical outcomes, such as survival rates and clinical complications of single crown restorations fabricated with resin-based CAD/CAM materials.

    Download PDF (938K)
Original article
  • Chika Arimizu, Yasunori Ayukawa, Rika Kuwatsuru, Satoru Haresaku, Yasu ...
    Type: research-article
    2020 Volume 62 Issue 4 Pages 356-359
    Published: 2020
    Released: September 26, 2020
    [Advance publication] Released: August 01, 2020
    JOURNALS FREE ACCESS

    Discontinuation of implant maintenance is the main risk factor for implant failure. The purpose of this study was to identify factors associated with previous discontinuation and resumption of maintenance among implant patients. A questionnaire survey was sent to 171 patients receiving implant maintenance at a university hospital; 169 patients responded. To assess the effect of job status, 26 patients (15.4%) with a history of maintenance discontinuation were classified as employed and nonemployed. The main reasons for previously discontinuing maintenance were work issues (in employed respondents) and dissatisfaction with treatment skill or chairside manner (in nonemployed respondents). The main reasons for resuming maintenance were those related to dental treatment (in employed respondents) and awareness of the importance of maintenance (in nonemployed respondents). There were significant differences in relation to job status in the reasons reported for discontinuing and resuming maintenance (both P < 0.05). The present findings suggest that oral health professionals should consider these factors when assisting patients in reducing the risk of implant failure.

    Download PDF (827K)
  • Hirofumi Kanazawa, Maki Yuguchi, Yosuke Yamazaki, Keitaro Isokawa
    Type: research-article
    2020 Volume 62 Issue 4 Pages 360-364
    Published: 2020
    Released: September 26, 2020
    [Advance publication] Released: August 12, 2020
    JOURNALS FREE ACCESS

    The upper and lower tooth-bearing jaws of the filefish (Stephanolepis cirrhifer) were scanned using a micro-CT system in order to address the existing gaps between the traditional pictures of the morphology and histology. 2D tomograms, reconstructed 3D models and virtual dissection were employed to examine and evaluate the in situ geometry of tooth implantation and the mode of tooth attachment both separately and collectively. No distinct sockets comparable to those in mammals were evident, but shallow depressions were observed in the premaxillary and the dentary. The opening of the tooth pulp cavity was not simply oriented towards the apparent tooth base in a direction opposite to the tooth apex. The opening was distorted basoposteriorly or basoanteriorly depending on the position of the tooth, and the edge of the pulp cavity opening was barely ankylosed; i.e. the sites of pleurodont ankylosis along the basoposterior or basoanterior edge of the opening appeared to closely match the contour of the shallow depression in the bone. These 3D findings appear to be very informative when considering the phylogeny of tooth attachment, suggesting that micro-CT would be a useful modality concurrent with or in advance of histological investigations.

    Download PDF (5407K)
  • Hye Min Cho, Dae-Woo Lee, Jeong Jae Park, Hye Mi Choi, Nam-Pyo Cho
    Type: research-article
    2020 Volume 62 Issue 4 Pages 365-370
    Published: 2020
    Released: September 26, 2020
    [Advance publication] Released: July 03, 2020
    JOURNALS FREE ACCESS

    This study aimed to clarify the risk factors of head and neck cancer (HNC) mortality, relative to those of all-cause and all-cancer mortalities, using the Korean National Health Insurance Service-Health Screening Cohort (NHIS-HEALS) data set. Data from 238 HNC deaths, 14,769 all-cancer deaths, and 38,086 all-cause deaths were extracted during a median follow-up period of 9.5 years. Baseline characteristics were assessed via chi-square tests, t tests, and multivariable logistic regression. HNC mortality was found to be positively associated with male sex, past and current smoking habits, moderate-to-heavy alcohol consumption, and being underweight. In addition, serum gamma-glutamyltransferase level was found to be significantly elevated in cases of HNC mortality. In contrast, obesity, a history of diabetes, and fasting blood glucose levels were found to be inversely associated with overall HNC mortality. Among the HNC subtypes, mortality due to laryngeal cancer was most strongly associated with past and heavy cigarette smoking, and mortality due to oro-/hypopharyngeal cancer was most strongly associated with heavy alcohol consumption. The present study demonstrates that this nationwide, population-based NHIS-HEALS data set can provide useful information for health research and policy development.

    Download PDF (871K)
  • Espen Helgeland, Torbjørn O. Pedersen, Ahmad Rashad, Anne C. Johanness ...
    Type: research-article
    2020 Volume 62 Issue 4 Pages 371-376
    Published: 2020
    Released: September 26, 2020
    [Advance publication] Released: July 17, 2020
    JOURNALS FREE ACCESS

    Tissue engineering for fibrocartilage regeneration using mesenchymal stromal cells (MSC) and biomaterial scaffolds is emerging as a promising strategy, but inhibiting vascularization to prevent endochondral ossification is important to develop stable implants. The objective of this study was to investigate the effect of angiostatin on inhibition of angiogenesis and promotion of chondrogenesis by collagen scaffolds with or without MSC implanted subcutaneously in rats. One scaffold from the following groups was implanted in each animal: Collagen scaffolds only, scaffolds functionalized with angiostatin, scaffolds loaded with MSC and scaffolds functionalized with angiostatin and loaded with MSC. The various scaffolds were harvested after 2 and 8 weeks for histological analysis, Real-time quantitative polymerase chain reaction (RT-qPCR) and immunofluorescence quantification. Results demonstrated significantly decreased expression of inflammatory (interleukin 1 alpha and beta) and angiogenic genes (platelet and endothelial cell adhesion molecule 1) in scaffolds functionalized with angiostatin after 2 weeks in vivo. Histologically, after 8 weeks, the scaffolds with angiostatin had less inflammatory cells and more collagen matrix formation, but no fibrocartilage formation was detected. Thus, although angiostatin suppressed angiogenesis, it did not stimulate ectopic chondrogenesis in tissue engineered constructs in vivo.

    Download PDF (3710K)
  • Takeshi Kase, Tetsuo Ohyama, Shinya Nakabayashi, Hiroyasu Yasuda, Taka ...
    Type: research-article
    2020 Volume 62 Issue 4 Pages 377-381
    Published: 2020
    Released: September 26, 2020
    [Advance publication] Released: August 01, 2020
    JOURNALS FREE ACCESS

    In this study, analytic models were used to simulate marginal resection in the area of the second premolar to the second molar region, and the mechanical effects on the mandible of residual bone mass, a maxillofacial prosthesis, and a reconstruction plate were evaluated by three-dimensional finite element analysis. As residual bone mass decreased, maximum principal stress increased near the anterior ramus of the mandible, and maximum shear stress increased at the anterior buccal region of the resected area. In the mandible with a maxillofacial prosthesis, the maximum principal stress distribution at the anterior ramus was lower, and the distribution of maximum shear stress at the anterior buccal region of the resected area was higher. When a reconstruction plate was used, maximum principal stress and maximum shear stress were lower. Thus, lower residual bone mass was associated with increased mandible deflection and torsion. In addition, presence of a maxillofacial prosthesis decreased deflection but increased torsion, and presence of a reconstruction plate decreased deflection and greatly decreased torsion. These findings suggest that decreased residual bone mass and maxillofacial prostheses increase fracture risk; however, presence of a reconstruction plate was effective in decreasing torsional stress, thereby reducing fracture risk in the mandible.

    Download PDF (2232K)
  • Shumpei Unno, Masamichi Shinoda, Kumi Soma, Asako Kubo, Barry J Sessle ...
    Type: research-article
    2020 Volume 62 Issue 4 Pages 382-386
    Published: 2020
    Released: September 26, 2020
    [Advance publication] Released: August 01, 2020
    JOURNALS FREE ACCESS

    To investigate neuronal activity involved in responses to noxious stimuli in conscious monkeys, the animals were subjected to a task that required them to detect a small change in facial skin temperature or light (second temperature: T2, second light: V2) relative to an initial condition (T1 or V1), and to detect changes in V2 along with a heat task. Recordings were obtained from 57 neurons in the ventral premotor cortex (PMv) during the heat or light detection task. T1 neurons and T2 neurons showed increased activity only during T1 or T2, and T1/T2 neurons were activated by both T1 and T2 stimuli. T1/T2 neurons showed an increase in firing at higher T1 temperatures, whereas T1 neurons did not. About half of the non-light/heat-sensitive T1/T2 neurons showed increased firing at higher T2 temperatures, whereas T2 neurons showed no such increase. The heat responses of heat-sensitive PMv neurons were significantly suppressed when monkeys shifted their attention from heat to light. The present findings suggest that heat-sensitive PMv neurons may be involved in motor responses to noxious heat, whereas light/heat-PMv neurons may be involved in emotional and motivational aspects of pain and inappropriate motor responses to allow escape from noxious stimuli.

    Download PDF (2663K)
  • Naohiko Sekine, Akiko Okada-Ogawa, Sayaka Asano, Daiki Takanezawa, Chi ...
    Type: research-article
    2020 Volume 62 Issue 4 Pages 387-392
    Published: 2020
    Released: September 26, 2020
    [Advance publication] Released: September 04, 2020
    JOURNALS FREE ACCESS

    The cause of burning mouth syndrome (BMS) is unknown. Although no effective treatment has been established, BMS patients frequently chew gum to alleviate pain. To identify the cause and new treatments for BMS, this study investigated the psychophysical and pharmacological properties of gum chewing to better understand its pain-relieving effects. In this prospective, blinded study, plasma catecholamine and serotonin levels and Profile of Mood States (POMS) scores were assessed after gum chewing or simulated chewing in 40 women (20 BMS patients and 20 age-matched controls). Visual analogue scale (VAS) scores for pain decreased significantly in BMS patients after gum chewing and simulated chewing. Moreover, resting VAS scores of BMS patients were significantly positively correlated with plasma adrenaline level. Furthermore, gum chewing was significantly correlated with lower plasma adrenaline level, VAS score, and tension-anxiety score. These results suggest that adrenaline is important in the pathogenesis of BMS pain and that the analgesic effect of gum chewing is induced through the potential effects of anxiety reduction, although this effect might not be specific to BMS. In addition, the analgesic effect of gum chewing was not induced solely by chewing motion.

    Download PDF (1233K)
  • Kazunori Hamamura, Hiroshi Hotta, Yoshiki Murakumo, Hidenobu Shibuya, ...
    Type: research-article
    2020 Volume 62 Issue 4 Pages 393-396
    Published: 2020
    Released: September 26, 2020
    [Advance publication] Released: July 17, 2020
    JOURNALS FREE ACCESS

    Stage-specific embryonic antigens (SSEA-1, 3, and 4) are carbohydrate antigens that have been used as markers of embryonic stem (ES) cells. However, the roles of these antigens in the establishment and maintenance of stemness of ES and induced pluripotent stem (iPS) cells are still poorly understood. This study investigated the biological and functional significance of globo-series glycolipids such as SSEA-3 and 4 in mouse iPS cells induced from tail-tip fibroblasts (TTFs) of α1,4Gal-T-knockout mice (lacking SSEA-3 and 4). These iPS cells were induced by retroviral transduction of four factors (Oct3/4, Sox2, Klf4, and c-Myc) into TTFs, and colonies were picked up. Morphologically, the colonies resembled ES cells and were positive for alkaline phosphatase and ES cell markers. Furthermore, in vitro-differentiated induction experiments after embryoid body formation revealed that some colonies derived from α1, 4Gal-T knockout mice were able to differentiate into three germ layers. Three germ layers were also observed in teratomas from iPS cells derived from α1,4Gal-T-knockout mice. These results suggest that SSEA-3 and 4 are not essential, at least for the establishment and maintenance of stemness of mouse iPS cells.

    Download PDF (3183K)
  • Bruno R. Chrcanovic, Peyman Ghiasi, Jenö Kisch, Liselott Lindh, Christ ...
    Type: research-article
    2020 Volume 62 Issue 4 Pages 397-401
    Published: 2020
    Released: September 26, 2020
    [Advance publication] Released: August 26, 2020
    JOURNALS FREE ACCESS

    The aim of this study was to compare the clinical outcomes of implant-supported overdentures (ODs) with either bar-clip or ball attachments. The implant, prosthesis failure, and technical complications were the outcomes analyzed in this retrospective clinical study conducted in a specialty clinic. Seventy-five patients with 242 implants supported by 76 ODs (36 maxillary, 40 mandibular) were included in the study and followed up for 88.8 ± 82.9 months (mean ± standard deviation). Bar-clip and ball attachments were used in 78.9% and 21.1% of the cases, respectively. Forty-three implant failures (17.8%) in 17 prostheses (17/76; 22.4%) were observed in this study. The average period of implant failure was 43.3 ± 41.0 months, and most of them were maxillary turned implants. The bar-clip system demonstrated more complications in the attachment parts compared to the ball attachment system. Poor retention of the prosthesis was similar between the two systems. Loss of implants resulted in the failure of 10 ODs in this study. ODs opposed by natural dentition or fixed prostheses presented with more complications. The Cox proportional hazards model did not show a significant effect on prosthesis failure for any of the factors. These findings indicated that patients with ODs need constant maintenance follow-ups to address the technical complications and perform prosthodontic maintenance regardless of the attachment system used.

    Download PDF (822K)
  • Tatsuaki Ito, Taku Toriumi, Keita Otake, Yuta Okuwa, Sho Tanaka, Yoshi ...
    Type: research-article
    2020 Volume 62 Issue 4 Pages 402-409
    Published: 2020
    Released: September 26, 2020
    [Advance publication] Released: August 31, 2020
    JOURNALS FREE ACCESS

    An inferior alveolar nerve (IAN) injury is a common clinical problem that can affect a patients’ quality of life. Cellular therapy has been proposed as a promising treatment for this injury. However, the current experimental models for IAN injury require surgery to create bone windows that expose the nerve, and these models do not accurately mimic human IAN injuries. Therefore, in this study, a novel experimental model for IAN injury has been established in rats. Using this model, the effects of Schwann cells and their role in the recovery from IAN injuries were investigated. Schwann cells were isolated from rat sciatic nerves and cultured. The first molar in the mandible was extracted and the IAN was immediately injured for 30 min by inserting an insect pin. Then, the Schwann cells or culture medium were transplanted into the extracted sockets of the cell and injury groups, respectively. After the surgery, the cell group displayed significantly increased sensory reflexes in response to mechanical stimulation, regenerated IAN width, and myelin basic protein-positive myelin sheaths when compared with the injury group. In conclusion, a novel animal experimental model for IAN injury has been developed that does not require the creation of a bone window to evaluate the impacts of cell transplantation and demonstrates that Schwann cell transplantation facilitates the regeneration of injured IANs.

    Download PDF (5683K)
  • Chiaki Matsubara, Junichi Furuya, Yutaka Watanabe, Michiyo Obana, Maki ...
    Type: research-article
    2020 Volume 62 Issue 4 Pages 410-414
    Published: 2020
    Released: September 26, 2020
    [Advance publication] Released: August 26, 2020
    JOURNALS FREE ACCESS

    This study aimed to identify factors associated with poor oral health status, as indicated by salivary occult blood (SOB) level, in community-dwelling older adults. A total of 592 community-dwelling participants aged 70 to 84 years with 20 to 28 teeth participated in the survey and SOB evaluation. Survey items included behaviors during dental visits, systemic diseases, smoking habit, cognitive function, and findings of intraoral examination. To identify factors associated with high SOB levels, binomial logistic regression analysis was performed after classifying participants as having high and low SOB on the basis of 75th-percentile SOB measurements. Presence of dental plaque (odds ratio [OR]: 2.26), poor subjective oral health (OR: 2.99) (for the age group 70 to 74 years), fewer remaining teeth (OR: 0.80), no dental visits during the previous year (OR: 2.80) (for the age group 75 to 79 years), and no dental visits during the previous year (OR: 3.93) (for the age group 80 to 84 years) were significantly associated with high SOB levels. The factors associated with high SOB, which indicates poor oral health status, differed by age group in community-dwelling older adults. Therefore, oral health management may improve oral health by providing different age groups with care that accounts for their physical and social functional abilities.

    Download PDF (838K)
  • Jennifer Galván-Pacheco, Marlen Vitales-Noyola, Ana M. González-Amaro, ...
    Type: research-article
    2020 Volume 62 Issue 4 Pages 415-419
    Published: 2020
    Released: September 26, 2020
    [Advance publication] Released: September 02, 2020
    JOURNALS FREE ACCESS

    This study sought to evaluate biofilm elimination using the HBW Ultrasonic Ring based on continuous ultrasonic irrigation. Forty-five premolars and molars with complex curvatures were included. An Enterococcus faecalis biofilm was established for 30 days on the extracted teeth. The teeth were then stratified into three experimental groups for instrumentation and irrigation (i.e. HBW Ultrasonic Ring, conventional irrigation, and passive ultrasonic irrigation). Pre- and post-instrumentation samples were collected, and reductions of bacterial load were evaluated by McFarland’s scale, counting of colony-forming units, and scanning electronic microscopy. The HBW Ultrasonic Ring promoted a higher reduction in bacterial load relative to conventional irrigation (P < 0.05) and a similar reduction compared with passive ultrasonic irrigation (P > 0.05). These results suggest the HBW Ultrasonic Ring is a promising alternative modality for simultaneous instrumentation and irrigation during root canal treatment, achieving an appropriate level of bacterial reduction and allowing the passage of the irrigating solution throughout the entire working length.

    Download PDF (2092K)
  • Maiko Iwaki, Manabu Kanazawa, Toshio Arakida, Shunsuke Minakuchi
    Type: research-article
    2020 Volume 62 Issue 4 Pages 420-422
    Published: 2020
    Released: September 26, 2020
    [Advance publication] Released: September 09, 2020
    JOURNALS FREE ACCESS

    This study compared the mechanical properties and molecular distribution of a polymethyl methacrylate (PMMA) block (Dry) with specimens that were fabricated by a conventional method and cured in a wet environment (Control). Two specimen types were fabricated with heat-curing denture base resin. Dry specimens were polymerized at high pressure and in a dry system, while Control specimens were polymerized with a heat-curing method, in accordance with the manufacturer’s recommended procedures. Specimens from each group were evaluated for three-point bending, water sorption and solubility, and color change, and by gel permeation chromatography (GPC). Mean values for the flexural strengths and moduli of the Dry specimens were significantly higher than those of the Control specimens (P > 0.05). Water sorption and discoloration values of the Dry group were significantly lower than those of the Control group. Mean weight-average molecular weights of the Dry group were higher than those of the Control group. As compared with the conventional method, the present method of fabricating PMMA blocks under high pressure yields superior mechanical properties for the denture base.

    Download PDF (861K)
  • Shunichiro Kato, Natsuko Tanabe, Mayu Nagao, Jumpei Sekino, Keiko Tomi ...
    Type: research-article
    2020 Volume 62 Issue 4 Pages 423-426
    Published: 2020
    Released: September 26, 2020
    [Advance publication] Released: August 31, 2020
    JOURNALS FREE ACCESS

    Purpose: Diabetes causes hyperglycemic disorders due to insufficient activity of insulin, and it also increases blood glucose level. Recent studies have reported the relationship between diabetes and periodontal disease. Periodontitis is advanced by inflammatory cytokines stimulated with LPS. The purpose of this study was to investigate the effects of hyperglycemia on the expression of inflammatory cytokines induced by LPS in osteoblasts.

    Methods: Cells were cultured for 7 and 14 days in the presence or absence of LPS and glucose. The expression mRNA level of IL-6, RANKL and OCN was determined using real-time PCR. The protein expression of IL-6 and RANKL was also measured using ELISA.

    Results: LPS and glucose increased the mRNA expression of IL-6, coupled with a decrease in the mRNA expression of OCN, which is associated with IL-6 and glucose. It also increased the protein expression of IL-6 compared to LPS. However, LPS+Glucose did not affect the mRNA and protein expression of RANKL. Furthermore, GLUT4 inhibitor, WZB117, blocked the stimulatory effect of glucose on LPS-induced IL-6 mRNA expression. WZB117 did not affect LPS-reduced OCN mRNA expression.

    Conclusion: These results suggest that high glucose levels increase LPS-induced IL-6 expression mediated by GLUT4.

    Download PDF (969K)
  • Awiruth Klaisiri, Suksantiphop Janchum, Kunyakorn Wongsomtakoon, Panuk ...
    Type: research-article
    2020 Volume 62 Issue 4 Pages 427-429
    Published: 2020
    Released: September 26, 2020
    [Advance publication] Released: August 24, 2020
    JOURNALS FREE ACCESS

    This study examined the effectiveness of resin infiltration in inhibiting microleakage from artificial white-spot lesions (AWL) in enamel. Fifty sound extracted premolars were selected and randomly divided into five groups (n = 10 each). Group 1 included sound teeth. In contrast, an AWL was created in all specimens in groups 2 to 5, as follows—Group 2: AWL with no treatment; Group 3: AWL treated with resin infiltration; Group 4: AWL treated with resin infiltration and 5,000 cycles of thermocycling; Group 5: AWL treated with resin infiltration and 10,000 cycles of thermocycling. All specimens were then coated with nail varnish, except for a 4 × 4 mm2 area on the buccal surface (the measurement area), immersed in 2% methylene blue solution, and sectioned buccolingually. Microleakage was evaluated with a stereomicroscope. Data were analyzed by using the Kruskal-Wallis test and Bonferroni post-hoc correction. Application of resin infiltrant reduced microleakage in AWL. No microleakage was seen in Group 3, and differences between Groups 3, 4, and 5 were not significant (P > 0.05). The resin infiltration technique appears to aid in sealing enamel AWL and may help provide long-term protection against microleakage in enamel AWL.

    Download PDF (1005K)
  • Dominic Gold, Sebastian F. Hahnel, Oliver Schierz, Angelika Rauch
    Type: research-article
    2020 Volume 62 Issue 4 Pages 430-434
    Published: 2020
    Released: September 26, 2020
    [Advance publication] Released: August 31, 2020
    JOURNALS FREE ACCESS

    Perception of tooth shades is subjective and not rated exactly the same by different individuals. In terms of dental esthetics, chairside individualization of dental restorations might help to improve patient satisfaction. This investigation aimed to validate the practicability of a chairside approach for staining resin-based composite restorations. Thirteen inexperienced and 13 experienced participants were recruited to first individualize two CAD/CAM resin-based composite crowns in randomized order with light-curing characterization material using two reference crowns as templates. They then evaluated the characterization procedure. The processing times were recorded, and the clinical quality of the individualized crowns was evaluated by two blinded master dental technicians. Of the 52 crowns examined, 90.4% were assessed as suitable for insertion; there was no difference in quality attributable to the different degrees of experience of the operators. The average time required for characterization of the second crown was significantly shorter than for the first crown (30.9/43.0 min), indicating that the procedure can be implemented using a chairside approach. Among the operators, 80.8% said they would use the individualization technique and staining material again. Chairside staining of CAD/CAM resin-based composite restorations with light-curing characterization materials is practicable and can be recommended for both experienced and inexperienced users.

    Download PDF (2035K)
  • Taichi Ishikawa, Jun Terashima, Yu Shimoyama, Yu Ohashi, Toshinari Mik ...
    Type: research-article
    2020 Volume 62 Issue 4 Pages 435-438
    Published: 2020
    Released: September 26, 2020
    [Advance publication] Released: September 02, 2020
    JOURNALS FREE ACCESS

    Ameloblastoma is a benign tumor that develops in the jawbone. Occasionally, however, it may become malignant and metastasize to other tissues. Although it has been suggested that various cytokines and several adhesion factors may play a role in its malignant transformation, the details have not been elucidated. In this context, it has been reported that butyric acid produced by periodontopathic bacteria causes progression of malignant tumors occurring in the mouth via podoplanin. However, the influence of butyric acid on ameloblastoma has not been clarified. In the present study, therefore, the expression of various cytokines and adhesion factors in ameloblastoma upon stimulation with butyric acid or cytokines was investigated using real-time reverse-transcription polymerase chain reaction. Three cell lines (HAM1, HAM2 and HAM3) established from the same ameloblastoma were used in the experiments. It was found that the expression of mRNAs for epidermal growth factor (EGF) and transforming growth factor beta 1 (TGFβ1) was increased in HAM2 and HAM3, respectively, upon stimulation with butyric acid. In addition, stimulation with EGF and TGFβ1 led to an increase in the expression of laminin β-3 mRNA in the respective cell lines. These results suggest that butyric acid may be involved in ameloblastoma exacerbation through the expression of laminin 332 (LM332) via EGF and TGFβ1 produced by ameloblastoma itself.

    Download PDF (1195K)
  • Liem Dang, Matthew Woliansky, Joseph Palamara, Jaafar Abduo
    Type: research-article
    2020 Volume 62 Issue 4 Pages 439-443
    Published: 2020
    Released: September 26, 2020
    [Advance publication] Released: September 09, 2020
    JOURNALS FREE ACCESS

    This study evaluated the effect of a modified tray design on the accuracy of implant impressions in comparison with the non-splinted and splinted impression techniques. Two titanium frameworks were produced to fit two parallel implants and two divergent implants with a 15o angle. According to the frameworks employed, two acrylic resin master models were fabricated. For each model, 10 impressions were taken with every technique. The maximum framework principal strain was calculated for every generated cast. For the parallel implant model, the strains of the non-splinted (118.4 με), splinted (89.0 με), and modified tray design impression (49.4 με) techniques were statistically similar (P = 0.16). For the divergent implant model, all the impression techniques showed a considerably higher strain than the parallel implant model. The splinted (287.0 με) and the modified (262.9 με) tray design impression techniques showed similar strains for the divergent implant model, which were significantly less than the strains for the non-splinted impression (518.0 με) technique (P < 0.05). Therefore, for two parallel implants, all the impression techniques exhibited similar accuracy. When angulation existed between the implants, the splinted and the modified tray design impression techniques were more accurate than the non-splinted impression technique.

    Download PDF (2179K)
  • Philippe François, Joseph Greenwall-Cohen, Stéphane Le Goff, Nathalie ...
    Type: research-article
    2020 Volume 62 Issue 4 Pages 444-448
    Published: 2020
    Released: September 26, 2020
    [Advance publication] Released: September 02, 2020
    JOURNALS FREE ACCESS

    Purpose: High-viscosity glass ionomer cements (HV-GICs) are reinforced with ultrafine, highly reactive glass particles, as well as a higher-molecular-weight polyalkenoic acid component. Silver diammine fluoride (SDF) is an agent with promising activity against active caries. The present study aimed to evaluate the shear bond strength (SBS) and interfacial morphology of a new HV-GIC bonded to dentin after treatment with various adhesive protocols including SDF.

    Methods: HV-GIC cylinders were bonded to dentin after various surface treatments (6 groups, n = 22): water; polyalkenoic acid; SDF; SDF + potassium iodide (KI); SDF + KI + polyalkenoic acid; SDF + KI + two weeks of storage in water + polyalkenoic acid. For each group, 20 samples were tested for SBS after 48 h, and 2 samples were cut and subjected to environmental scanning electron microscopy (E-SEM) and energy-dispersive X-ray (EDX) analysis.

    Results: No significant differences in SBS were found between any of the protocols tested. However, E-SEM and EDX images showed different interfaces when SDF was applied.

    Conclusion: SDF has no influence on the adhesion of HV-GIC to sound dentin and could potentially improve the cario-resistance of the dentin/HV-GIC interface.

    Download PDF (1475K)
Short Communication
  • Yukiko Takahashi, Hisako Hikiji, Tatsuji Nishihara
    Type: Short Communication
    2020 Volume 62 Issue 4 Pages 449-451
    Published: 2020
    Released: September 26, 2020
    [Advance publication] Released: September 04, 2020
    JOURNALS FREE ACCESS

    The aim of the present study was to gather information to clarify the scope of oral health services in Asia, focusing particularly on the role of dental hygienists, anticipating that international exchange of data on oral health would benefit the establishment of such systems in other countries. Data on oral health providers were obtained from reliable sources, cited reports and professional websites, or from embassies of Asian countries located in Japan. The embassies were contacted by email, telephone, post, or interview. The survey was conducted from February 1, 2015, until June 18, 2019. Twenty-eight countries in Asia were selected according to their classification by the United Nations. Among them, 14 countries were found to recognize the professional status of dental hygienists. Nine of the 28 countries had no working dental hygienists, and their role was taken by other oral hygiene providers. It was unclear whether oral hygiene providers were operating in 5 of those countries. Many countries were found to lack formal oral health systems, and some had limited systems in rural areas. Dental hygienists work to prevent oral diseases in order to protect teeth and gums, as is the case in Japan. However, other oral health providers offer other dental services in other Asian countries, probably depending on individual national circumstances.

    Download PDF (920K)
  • Mattia Di Bartolomeo, Arrigo Pellacani, Sara Negrello, Luigi Chiarini, ...
    Type: Short Communication
    2020 Volume 62 Issue 4 Pages 452-454
    Published: 2020
    Released: September 26, 2020
    [Advance publication] Released: August 24, 2020
    JOURNALS FREE ACCESS

    The Coronavirus disease 2019 (COVID-19) pandemic suddenly took the world by storm and Italy was one of the hardest hit countries. Maxillo-facial surgery and dentistry procedures had to be significantly reorganized, since they are considered high-risk procedures. Protocols had to be changed and interdepartmental cooperation was put in place to plan surgical interventions and maintain high standards. Various improvements have been made to prevent and reduce the risks of spreading the infection. Even if the situation seems to have improved, being unprepared is not an option. In this paper the experience gained during these months has been shared and possible future challenges has been highlighted, suggesting practical adjustments based also on new guidelines and recommendations.

    Download PDF (768K)
Case Report
  • Mythili Kalladka, Hussein Alhasan, Nagaraju Morubagal, Noboru Noma, Ju ...
    Type: case-report
    2020 Volume 62 Issue 4 Pages 455-457
    Published: 2020
    Released: September 26, 2020
    [Advance publication] Released: September 09, 2020
    JOURNALS FREE ACCESS

    Complex regional pain syndrome (CRPS)—an extremely painful primary pain disorder related to trauma—is rare in the orofacial region. The authors describe a case of orofacial CRPS with a clinical phenotype that fits the Budapest diagnostic criteria. A 39-year-old female patient presented with left-side facial pain that had been untreated for 10 months. Symptoms included burning pain and allodynia accompanied by swelling and redness on exposure to cold or stress. The diagnosis was confirmed after stellate ganglion anesthetic block resulted in substantial improvement.

    Download PDF (997K)
  • Carlos A. Jurado, Akimasa Tsujimoto, Jose Villalobos-Tinoco, Hidehiko ...
    Type: case-report
    2020 Volume 62 Issue 4 Pages 458-460
    Published: 2020
    Released: September 26, 2020
    [Advance publication] Released: August 31, 2020
    JOURNALS FREE ACCESS

    The purpose of this case report is to describe a minimally invasive technique for non-vital tooth bleaching using traditional Japanese paper, known as washi. Non-vital tooth bleaching with a mixture of sodium perborate and 30% hydrogen peroxide rolled in Japanese paper for a traumatically injured tooth, and in-office vital-tooth bleaching for the upper front six teeth and first premolars, were performed. Five-year follow-up showed satisfactory stability in the bleaching effects and did not show any problems in the traumatically injured tooth. The use of Japanese paper for non-vital tooth bleaching may minimize damage to discolored non-vital teeth.

    Download PDF (2284K)
feedback
Top