Journal of Oral Science
Online ISSN : 1880-4926
Print ISSN : 1343-4934
ISSN-L : 1343-4934
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Showing 1-25 articles out of 25 articles from the selected issue
Review
  • Shoko Miura, Masanori Fujisawa, Futoshi Komine, Toshio Maseki, Takumi ...
    Type: review-article
    2019 Volume 61 Issue 2 Pages 195-199
    Published: 2019
    Released: June 18, 2019
    [Advance publication] Released: May 21, 2019
    JOURNALS FREE ACCESS

    Interim restoration protects abutment teeth and periodontal tissues until prosthetic treatment ends with the fabrication of a definitive prosthesis, restores and maintains the functions and morphology of the stomatognathic system, and preserves the occlusal contact relationship. Temporary prostheses are used for a short time, to confirm the diagnosis and treatment plan. However, because interim restorations are used only briefly, their importance in ensuring the success of definitive prostheses is often overlooked. This review includes a comprehensive literature review of interim restoration of molars and summarizes the current clinical understanding and status of this functionally important area. Peer-reviewed publications were identified by searching PubMed in November 2018. An interim restoration, even when used briefly, can help dentists evaluate many aspects of the treatment plan and contribute to accurate prognosis of prosthetic treatment.

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Original
  • Xiang Yan, Tiancong Wang, Han Su
    2019 Volume 61 Issue 2 Pages 200-205
    Published: 2019
    Released: June 18, 2019
    JOURNALS FREE ACCESS

    This study was conducted to investigate the short-term effects of a self-ligating appliance for orthodontic treatment of severe adult periodontitis. Thirty patients diagnosed as severe periodontitis were recruited at Nanjing Stomatological Hospital, P. R.China, between January 2012 and January 2016. General clinical and demographic data were collected from the patients, all of whom were treated with a self-ligating appliance. Probing pocket depth (PPD), clinical attachment level (CAL), bleeding on probing (BOP) and plaque index (PI) were measured before appliance placement, and at 1 and 3 months after appliance placement, respectively. Results showed the rate of tooth loss, mean PPD, mean CAL and the BOP ratio were more favorable in healthy subjects than in the patients. Smokers accounted for a significantly higher proportion of the patients in comparison with the healthy subjects. Clinical outcomes revealed that both the mean PPD and mean CAL were significantly decreased compared with the baseline (P < 0.05). Furthermore, the percentage of BOP, PI and bone mineral density were also significantly decreased at 1 month after treatment (P < 0.05). The volume of gingival crevicular fluid, as well as the levels of alkaline phosphatase, aspartate aminotransferase and glutathione peroxidase, were significantly increased in the first month after treatment, being decreased at 2 months, and finally returning to normal in the third month. In summary, orthodontic treatment using a self-ligating appliance can apparently improve the periodontal condition of patients with severe adult periodontitis.

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  • Anqing Du, Yawei Cheng, Sen Zhao, Xiaoxia Wei, Yi Zhou
    Type: research-article
    2019 Volume 61 Issue 2 Pages 206-212
    Published: 2019
    Released: June 18, 2019
    [Advance publication] Released: May 21, 2019
    JOURNALS FREE ACCESS

    Cigarette smoking is a lifestyle-related risk factor involved in the causation and progression of periodontal disease. Nicotine is a key toxic component of tobacco. However, the mechanisms underlying nicotine-induced periodontitis have not yet been fully elucidated. The present study investigated the microRNA (miRNA) expression profile of human periodontal ligament cells (PDLCs) treated with nicotine. Using differential analysis of miRNA array data, several differentially expressed miRNAs were identified in nicotine-treated PDLCs. Quantitative real-time PCR was employed to verify the accuracy of the miRNA array, and the targets of these dysregulated miRNAs were further analyzed. Function and pathway enrichment of differentially expressed miRNAs suggested that several important signaling pathways, such as the Toll-like receptor signaling pathway, nicotine addiction, the transforming growth factor-beta signaling pathway, and the hypoxia inducible factor-1 signaling pathway, are potentially responsible for nicotine-induced periodontitis. This study has helped to clarify the epigenetic mechanisms of nicotine-induced periodontitis, highlighting novel biomarkers and therapeutic targets.

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  • Giulio Rasperini, Gaia Pellegrini, Jim Sugai, Cesare Mauro, Simone Fio ...
    2019 Volume 61 Issue 2 Pages 213-220
    Published: 2019
    Released: June 18, 2019
    [Advance publication] Released: March 30, 2019
    JOURNALS FREE ACCESS

    The present study aimed to assess the effects of a multimicronutrient food supplement on periodontal clinical parameters and systemic/local inflammatory markers. Thirty patients with severe chronic periodontitis who adhered to the Mediterranean diet (MD) underwent non-surgical therapy and daily took either the micronutrient complex (group-A) or olive oil (group-B) from baseline (T0) to 3 months (T2). Supragingival debridement was performed at T0. One month later (T1), one-stage-full-mouth disinfection was performed. Periodontal clinical parameters were monitored and correlated with serum C-reactive protein (CRP) and salivary matrix metalloproteinase-8/9 (MMPs-8/9) quantified at each time point. Longitudinal analysis revealed that in group-A, the MMP-8/-9 levels were decreased at T2 compared with at T0 (P = 0.013 and P = 0.004, respectively) and that the MMP-9 levels were decreased at T1 (P = 0.004). These reductions were not significant in group-B. The CRP levels in both groups did not change over time. No between-group differences were noted for any parameter. The correlation between the full-mouth bleeding score and the MMP-8 level in both groups was significant (P < 0.001). The investigated local and systemic inflammatory parameters were not affected by the tested multimicronutrient supplement in patients who adhered to MD. In conclusion, MMP-8 is useful for assessing the reduction in periodontal inflammation.

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  • Murtaza Saleem, Nobuo Yoshinari, Suguru Nakamura, Yasunori Sumi, Yukik ...
    Type: research-article
    2019 Volume 61 Issue 2 Pages 221-228
    Published: 2019
    Released: June 18, 2019
    [Advance publication] Released: March 30, 2019
    JOURNALS FREE ACCESS

    Dry mouth, caused by decreased salivary gland function and/or weak salivary stimulation, can severely affect oral health in older individuals. Therefore, the aim of this study is to evaluate whether a lip trainer device and sonic toothbrush can improve salivary flow and oral wetness in older patients complaining of dry mouth. Overall, 39 subjects aged ≥60 years who had at least 20 natural teeth were randomly assigned to use a lip trainer device (group P, n = 13) or a sonic toothbrush (group S, n = 13). The subjects who did not experience oral dryness were included as controls (group C; n = 13). The unstimulated and stimulated salivary flow rates and oral wetness were measured at baseline, 1 and 6 months. The unstimulated salivary flow significantly increased in both groups at 1 and 6 months (P < 0.05). The stimulated salivary flow was also significantly increased in group P (P < 0.01) compared with the level at baseline. However, no significant difference was observed over time in group S. Oral wetness of the tongue and buccal mucosa in group P had significantly improved at 1 and 6 months (P < 0.05). Dry mouth in older individuals may be improved by using a lip trainer device or a sonic toothbrush.

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  • Essam A. Alsanawi, Raghib Abusaris, Ashraf A. El-Metwally
    Type: research-article
    2019 Volume 61 Issue 2 Pages 229-237
    Published: 2019
    Released: June 18, 2019
    JOURNALS FREE ACCESS

    This study aimed to investigate cross-cultural adaptation and validation of the Arabic version of the Index of Dental Anxiety and Fear (IDAF-4C). A total of 167 participants completed the questionnaire with a response rate of 72.6%. The participants were asked to complete the adapted Arabic version of the IDAF-4C and the modified dental anxiety scale (MDAS). The participants were asked to complete the second form of the Arabic version of the IDAF-4C over a period of 1 week to determine the reproducibility of the index. The internal consistency of the IDAF-4C was high (Cronbach’s alpha, 0.94). The intraclass correlation coefficients for total score and each item were high (range, 0.98-0.99). In addition, the Kappa statistics for the total score and each item were high (range, 0.83-0.97). The Spearman’s correlation coefficients between the IDAF-4C total and the component scores were high (r = 0.86-0.92, P < 0.001). In addition, the IDAF-4C total and the component scores were significantly associated with the MDAS score (r = 0.67-0.71). The adapted Arabic version of the IDAF-4C demonstrated suitable psychometric properties. The current study indicates that the Arabic version of the IDAF-4C might be a suitable index to measure dental anxiety and fear in Arabic-speaking populations.

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  • Michiko Furuta, Kakuhiro Fukai, Jun Aida, Yoshihiro Shimazaki, Yuichi ...
    Type: research-article
    2019 Volume 61 Issue 2 Pages 238-245
    Published: 2019
    Released: June 18, 2019
    JOURNALS FREE ACCESS

    This nationwide cross-sectional survey investigated the association between periodontal disease and self-reported systemic health in periodontal patients who regularly visited private dental clinics in Japan. Data from 999 patients of 444 dental clinics were analyzed; the patients were aged 40 years or older, regularly visited dentists, and had diagnosed periodontal disease (defined as two or more teeth with a clinical attachment level ≥6 mm). Medical history was collected with a self-reported questionnaire. Number of teeth with a probing pocket depth (PPD) ≥5 mm was used to define periodontal status, and the highest quartile was used as the dependent variable. A Poisson regression model showed that histories of diabetes and hypertension were associated with a larger number of teeth with a PPD ≥5 mm (diabetes: prevalence rate ratio [PRR] 1.36, 95% confidence interval [CI] 1.00-1.85; hypertension: PRR 1.27, 95% CI 1.02-1.58) after adjusting for potential periodontal risk factors. These findings suggest that diabetes and hypertension are associated with worse periodontal disease. Dentists should confirm the diabetes and hypertension status of patients who receive maintenance care, because these conditions could affect periodontal management of patients.

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  • Merve B. Güngör, Seçil K. Nemli, Bilge T. Bal, Evşen Tamam, Handan Yıl ...
    Type: research-article
    2019 Volume 61 Issue 2 Pages 246-254
    Published: 2019
    Released: June 18, 2019
    [Advance publication] Released: April 22, 2019
    JOURNALS FREE ACCESS

    This study compared the fracture resistance of monolithic and veneered all-ceramic four-unit posterior fixed dental prostheses (FDPs) generated by computer-aided design/computer-aided manufacturing (CAD/CAM) after aging in a mastication simulator. Four-unit FDPs were designed from six different all-ceramic systems: 1) monolithic lithium disilicate (M-E), 2) monolithic zirconia (M-TZI), 3) veneered zirconia by conventional layering (V-L), 4) veneered zirconia by lithium disilicate pressing (V-P), 5) veneered zirconia by lithium disilicate fusing (CAD-F-E), and 6) veneered zirconia by feldspathic ceramic cementing (CAD-C-CB). The specimens were divided into control and aging groups (n = 10 per group). The aging process included both thermocycling and mechanical loading and was followed by fracture resistance testing. All specimens in the M-E, M-TZI, and V-L groups survived; however, all specimens in the V-P group were fractured during artificial aging. The highest fracture resistance values were observed in the M-TZI group. According to the fracture resistance test, connector fractures were the most frequent type of failure. M-TZI and M-E FDPs revealed no failures during aging and showed higher fracture resistance than the veneered groups. Among the veneered zirconia framework groups, V-L FDPs showed the highest success rate during aging, while the fracture resistance was similar among all the veneered zirconia groups.

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  • Gang Zhou, Hong Peng, Ying-si Wang, Xiao-mo Huang, Xiao-bao Xie, Qing- ...
    Type: research-article
    2019 Volume 61 Issue 2 Pages 255-263
    Published: 2019
    Released: June 18, 2019
    JOURNALS FREE ACCESS

    Bacterial biofilms, formed on biotic or abiotic surfaces, can lead to serious environmental or medical problems. Therefore, it is necessary to find novel antimicrobial agents to combat biofilms, or more effective combinations of existing biocides. In this study, initial biofilms of Pseudomonas aeruginosa ATCC 9027 and Staphylococcus aureus ATCC 6538 in the presence of xylitol or xylitol and isothiazolones were determined using crystal violet staining in 96-well microplates and confocal laser scanning microscopy. Xylitol and isothiazolones exhibited enhanced synergistic inhibition of initial biofilm formation, and also the structure and production of extracellular polymeric substances by P. aeruginosa ATCC 9027 and S. aureus ATCC 6538 in a dose-dependent manner. In addition, xylitol and isothiazolones inhibited and restored the swimming motility of P. aeruginosa ATCC 9027, respectively. These findings show that a combination of xylitol and isothiazolones exerts pronounced antimicrobial activity against P. aeruginosa and S. aureus biofilms and may be applicable for preventing or reducing bacterial biofilms in vitro.

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  • Tomotaka Kato, Shinsuke Mizutani, Yojiro Umezaki, Seiichi Sugiyama, To ...
    Type: research-article
    2019 Volume 61 Issue 2 Pages 264-269
    Published: 2019
    Released: June 18, 2019
    JOURNALS FREE ACCESS

    Type D personality—the tendency toward combined negative affectivity and social inhibition—is a risk factor for coronary heart disease. Although Type D personality has been linked to low adherence to diabetic care, it is unclear whether it is related to adherence to dental therapy. Thus, study examined the relationship between Type D personality and withdrawal from dental therapy. A web-based questionnaire was used to compare a treatment dropout group (n = 225) and maintenance group

    (n = 236). The questionnaire was designed to assess Type D personality traits, reasons for dropout, and respondent sociodemographic characteristics and attitudes. There were no significant differences in the sociodemographic characteristics of the two groups. However, the proportion of respondents with a Type D personality was significantly larger in the dropout group than in the maintenance group (P = 0.04). The most common reasons for dental therapy dropout were “improvement of symptoms” (46.2%) and “busy with business or study” (30.7%). The most frequent attitude reported in the dropout group was negative feelings toward dental practice. In conclusion, Type D personality might be related to dropout from dental therapy.

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  • Sebastian Hahnel, Stephanie Krifka, Michael Behr, Carola Kolbeck, Rein ...
    Type: research-article
    2019 Volume 61 Issue 2 Pages 270-275
    Published: 2019
    Released: June 18, 2019
    [Advance publication] Released: March 30, 2019
    JOURNALS FREE ACCESS

    This study investigated the handling properties and clinical performance of two commercially available resin materials with slight differences in filler composition for the fabrication of fixed interim restorations. In a dental university setting, patients requiring prosthetic treatment were supplied with fixed interim restorations fabricated from two commercially available resin materials. To clarify the handling properties of the resin materials, dentists and undergraduate students completed a questionnaire. Prior to insertion of the definitive restoration, the interim restorations were analyzed by calibrated examiners using a modification of the United States Public Health Service criteria. Eighty-two fixed interim restorations with a mean clinical service period of 44.5 (±28.3) days were included, including 39 single crowns, 30 fixed denture prostheses, 10 blocked crowns, and 3 partial coverage restorations. No significant differences between the two materials in the rating of their handling properties were identified, with the exception of the parameter “surface”. Failures due to fractures were observed in 13% of the interim restorations. No significant differences between the materials in the rating of the clinical performance were identified. These results indicate that slight changes in the filler composition of commercial formulations account for few differences in handling properties and clinical performance.

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  • Toshiki Takamizawa, Akimasa Tsujimoto, Ryo Ishii, Maho Ujiie, Mami Kaw ...
    Type: research-article
    2019 Volume 61 Issue 2 Pages 276-283
    Published: 2019
    Released: June 18, 2019
    JOURNALS FREE ACCESS

    The purpose of this study was to examine the effect of desensitizing dentifrices containing stannous fluoride (SnF2) on dentinal tubule occlusion. Two experimental dentifrices with the same ingredients but different SnF2 concentrations (Group II, 0.4% w/w; Group III, 0.454% w/w) were used; distilled water was used in the control group (Group I). Third molars were collected from Japanese and American dental patients. The crowns were removed and sectioned to obtain dentin discs, which were further cut into quarters. Thirty-six specimens each from Japanese and American patients were divided into three sets (n = 12 each) and assigned to each of the three treatment groups. The specimens were brushed for 10 s twice per day for 4 days. After treatment, the discs were observed by scanning electron microscopy, and the extent of dentinal tubule occlusion in the images was expressed on a five-point categorical scale. Group II and III specimens from Japanese and American patients showed greater dentinal tube occlusion than those from Group I, but the differences were not statistically significant. The present results suggest that both SnF2 concentrations mitigate dentin hypersensitivity, regardless of patient ethnicity.

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  • Takayuki Mashimo, Yukio Sato, Daisuke Akita, Taku Toriumi, Shunsuke Na ...
    Type: research-article
    2019 Volume 61 Issue 2 Pages 284-293
    Published: 2019
    Released: June 18, 2019
    JOURNALS FREE ACCESS

    Bone marrow-derived mesenchymal stem cells (BMMSCs) remain the most widely used source of osteogenic cells in bone tissue engineering research. A cell-based treatment for alveolar ridge augmentation has received attention as an alternative to bone grafting. In the present study, BMMSC transplantation into tooth extraction sockets of C57BL/6J mice was evaluated for alveolar ridge regeneration. The first right maxillary molars were extracted, and then BMMSCs (PDGFRα+ Sca-1+ CD45 TER119 cells) isolated from femoral and tibial bone marrow were immediately transplanted into the extraction sockets. A control group underwent the same procedure except for BMMSC transplantation. Bone formation in the sockets was evaluated using micro-computed tomography and histological and immunohistochemical analyses. At 3 weeks, bone formation in the sockets was more advanced in the experimental group than in the control group. Histological analysis at 6 weeks after transplantation showed that the sockets in the experimental group also contained a greater quantity of bone marrow. Interestingly, socket bone mineral density was lower in the experimental group than in the control group at 6 weeks. These findings suggest that BMMSC transplantation accelerates bone healing and augments bone marrow formation in tooth extraction sockets.

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  • Hakan Gokturk, Ugur Aydin, Ismail Ozkocak, Mehmet E. Aydemir
    Type: research-article
    2019 Volume 61 Issue 2 Pages 294-299
    Published: 2019
    Released: June 18, 2019
    JOURNALS FREE ACCESS

    The present study aimed to evaluate the degree of crack formation during canal preparation using reciprocating files. A total of 120 incisor teeth were divided into eight groups according to irrigation protocol (n = 15). The irrigation solution and chelating agents included distilled water, sodium hypochlorite (NaOCl), citric acid, maleic acid, peracetic acid, ethylenediaminetetraacetic acid (EDTA) gel, and EDTA liquid. The root canals were prepared using reciprocating instruments while one of the agents was present within the root canals. A control group was subjected to neither preparation nor irrigation. The roots were horizontally sectioned 3, 6, and 9 mm away from the apices. The numbers of cracks were recorded. Statistical analyses were performed using a chi-squared test. The chelating agents resulted in similar numbers of cracked sections. The use of one of the chelating agents during preparation using reciprocating instruments appears to be beneficial in reducing crack formation.

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  • Takahiro Iwasaki, Akiko Hirose, Tetsuji Azuma, Tamie Ohashi, Kazutoshi ...
    Type: research-article
    2019 Volume 61 Issue 2 Pages 300-306
    Published: 2019
    Released: June 18, 2019
    JOURNALS FREE ACCESS

    Dental caries could be a risk factor for metabolic syndrome (MetS); however, there is limited evidence of such a relationship in the literature. This cross-sectional study investigated the relationships among dental caries experience, dietary habits, and MetS in Japanese adults. A total of 937 participants aged 40-74 years underwent a health check, including dental examination. Decayed, missing, and filled teeth (DMFT) were used as an index of caries experience. The mean DMFT score was 14, and 12% of the participants had MetS in this study. Multivariate logistic regression analyses showed that the prevalence of MetS was significantly related to DMFT (first vs. fourth quartile, odds ratio [OR] = 1.80; P < 0.05). In addition, the OR of DMFT for MetS was found to be greater in each successively higher DMFT quartile. The prevalence of MetS was significantly related to daily coffee consumption (OR = 0.51, P < 0.01), and the relationship between DMFT and MetS was noted after adjusting for daily coffee consumption. There appears to be a positive association between caries experience and MetS in Japanese adults. This relationship increased with the increase in DMFT regardless of dietary habits.

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  • Ryota Sone, Nobuhiko Eda, Keisei Kosaki, Momoko Endo, Koichi Watanabe
    Type: research-article
    2019 Volume 61 Issue 2 Pages 307-312
    Published: 2019
    Released: June 18, 2019
    JOURNALS FREE ACCESS

    This study, employing an exercise versus control crossover design, was conducted to investigate the influence of acute high-intensity exercise on salivary nitric oxide (NO) levels. Nine healthy males (aged 23.8 ± 1.4 years) performed ergometer exercise at 80%VO2peak for 60 min, whereas controls sat at rest for 60 min. Saliva samples were collected before (Pre: 0800 h) and after (Post 0-h: 0900 h, Post 1-h: 1000 h, Post 2-h: 1100 h, Post 3-h: 1200 h) the interventions. Salivary NO levels were determined by colorimetric assay. It was found that the salivary NO levels in controls were decreased (P < 0.05) at Post 0-h (−94 ± 15), Post 1-h (−80 ± 20), Post 2-h (−92 ± 34) and Post 3-h (−145 ± 39) relative to the Pre values. Under exercise conditions, salivary NO levels did not change after high-intensity ergometer exercise relative to the Pre values. Thus, the response of salivary NO levels appeared to differ between high-intensity ergometer exercise and inactivity, that exercise-related stress induces the production of salivary NO.

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  • Hideki Takai, Andre J. van Wijnen, Yorimasa Ogata
    Type: research-article
    2019 Volume 61 Issue 2 Pages 313-320
    Published: 2019
    Released: June 18, 2019
    JOURNALS FREE ACCESS

    Periodontitis leads to destruction of periodontal ligament, cementum and alveolar bone. Regeneration of periodontal tissue is dependent on mesenchymal stem cells (MSC) present in the periodontal ligament, and transcription factors determine the direction of MSC differentiation. The present study was conducted to investigate the transcription factors that are crucial for maintaining the characteristics of the periodontal ligament. The mRNA levels of several transcription factors were measured in cultured human periodontal ligament (HPDL) cells, human gingival fibroblasts and osteoblast-like Saos2 cells. HPDL cells were transfected for 72 h with siTwist2, siKlf12, or siMix (siTwist2, siPax9, and siKlf12). The cells were then harvested and subjected to real-time PCR and Western blotting. siTwist2 suppressed the levels of Twist2, Sox2 and Col1a1 mRNAs, and increased those of Sox5 and aggrecan mRNAs. siKlf12 decreased the mRNA levels of Klf12, Runx3, Zfp521, and Stab2, and increased those of Sox2, Klf4, and the MSC markers CD90 and CD105. These results suggest that transfection with siMix and siTwist2 induced chondrogenesis, and that siKlf12 induced the differentiation of MSC in HPDL cells. Thus, inhibition of Twist2 or Klf12 induced the differentiation of chondrogenic or mesenchymal stem cells in this setting, suggesting that the characteristics of HPDL cells may be altered by inhibition of specific transcription factors.

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  • Toshiya Endo, Akira Komatsuzaki, Yukio Miyagawa, Takeshi Kamoda, Sho G ...
    Type: research-article
    2019 Volume 61 Issue 2 Pages 321-326
    Published: 2019
    Released: June 18, 2019
    JOURNALS FREE ACCESS

    This study was conducted to assess the usefulness of thermography for quantifying facial temperature before and after orthognathic surgery and intermaxillary fixation, and the effects of these orthognathic procedures on facial temperature. Facial thermograms of 10 patients who underwent bilateral sagittal split ramus osteotomy (SSRO, one-jaw group) and another 10 patients who underwent Le Fort I osteotomy and bilateral SSRO (two-jaw group) were taken 1 day before orthognathic surgery (T1) and at release of intermaxillary fixation 7 days later (T2). Two thermograms taken 30 s (TG1) and 3 min (TG2) after the start of recording at T1 and T2 were used. A square (26 × 26 pixels) was marked on each thermogram and the mean facial temperature for each square was measured. Three-way analysis of variance was used for statistical comparisons. Facial temperatures were significantly higher at T2 than at T1 on TG1 and TG2, and were significantly higher on TG2 than on TG1 at T1 and T2. The two-jaw group had a significantly higher facial temperature than the one-jaw group. Thermography was useful for quantitative assessment of facial temperature in patients undergoing orthognathic surgery. Changes in facial temperature were due predominantly to inflammation after surgery, rather than to sarcopenia.

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  • Fumiaki Kimura, Futoshi Komine, Kei Kubochi, Shogo Yagawa
    Type: research-article
    2019 Volume 61 Issue 2 Pages 327-334
    Published: 2019
    Released: June 18, 2019
    JOURNALS FREE ACCESS

    This study investigated bond strength of CAD/CAM-manufactured composite resin and ceramic veneers to a zirconia framework and analyzed the effect of treatments of veneer surfaces. A CAD/CAM resin-based (AVE) composite or lithium disilicate ceramic (IEC) block was used as the veneer material. AVE and IEC specimens were assigned to receive one of three surface treatments (n = 22): no surface treatment, acid-etching with 9.5% hydrofluoric acid gel, and airborne-particle abrasion with alumina particles. Zirconia disks and AVE or IEC specimens in each group were bonded with a resin-based luting agent, and shear bond strength of the specimens was measured at 0 and 20,000 thermocycles. Significant differences were assessed by the Steel-Dwass test for multiple comparisons and Mann-Whitney U-test (α = 0.05). As compared with other surface treatments, bond strengths were significantly higher at 0 and 20,000 thermocycles in the airborne-particle abraded AVE and acid-etched IEC specimens. Airborne-particle abrasion of the surface of AVE specimens increased bond strength between AVE veneers and zirconia frameworks, while hydrofluoric acid treatment enhanced bond strength between IEC veneers and zirconia frameworks.

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  • Abir Majbauddin, Chika Tanimura, Haruka Aoto, Shinji Otani, Maria C. E ...
    2019 Volume 61 Issue 2 Pages 335-342
    Published: 2019
    Released: June 18, 2019
    JOURNALS FREE ACCESS

    Diabetes mellitus (DM) with poor glycemic control is often linked to oral manifestations. This study aimed to investigate the association between dental caries (DC) and glycated hemoglobin (HbA1c) among patients with type 2 DM (T2DM). A health center-based cross-sectional study was conducted comprising 91 eligible patients with T2DM (21 males and 70 females) with a mean age (± standard deviation) of 61.49 ± 9.71 years. A structured interview, screening for DM-related factors, and oral examination were performed. Serum HbA1c levels were used as an index for glycemic control. A comparison between patients with controlled T2DM, i.e., HbA1c ≤7.0% (n = 46), and uncontrolled T2DM, i.e., HbA1c >7.0% (n = 45), showed significant differences in mean values of decayed teeth (DT) (P = 0.045); missing teeth (P = 0.002); and decayed, missing, and filled teeth (DMFT) index (P < 0.001). Results of multiple linear regression analysis revealed that the number of DT was significantly correlated with serum HbA1c levels (95% confidence interval [CI] 0.173 to 0.972, P = 0.005). Furthermore, DMFT index values and serum HbA1c levels (95% CI 0.532 to 1.658, P < 0.001) showed a significant association. This study provides substantial evidence on the association between DC indicators and serum HbA1c levels.

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  • Philipp Kanzow, Steffi Baxter, Marta Rizk, Torsten Wassmann, Annette W ...
    Type: research-article
    2019 Volume 61 Issue 2 Pages 343-350
    Published: 2019
    Released: June 18, 2019
    JOURNALS FREE ACCESS

    The study aimed to compare the repair bond strength of aged composite and amalgam repaired with resin composite after various mechanical and adhesive surface treatments. Specimens were aged by thermal cycling (10,000 cycles, 5-55°C) and randomly subjected to one of three surface treatments: diamond bur abrasion, aluminum oxide air abrasion, or silica coating. Conventional bonding or a universal adhesive with incorporated silane was applied afterward (each n = 16) and resin composite was attached. In the control groups (each n = 16), resin composite was attached using one of the above adhesives without prior mechanical surface conditioning. After further thermal cycling, the shear bond strength (SBS) and failure modes were assessed. Statistical analyses were performed using ANOVA, Weibull statistics, two sample t-tests, and Chi2-test (P < 0.05). The SBS of the repaired amalgam was significantly lower than that of the composite and mechanical pretreatment significantly increased SBS. The universal adhesive significantly improved the SBS of the repaired amalgam compared to the conventional bonding agent and mechanical pretreatment increased the number of cohesive/mixed failures. Amalgam restorations may be repaired using resin composites, but the resulting SBS is lower than that obtained with composite.

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  • Pinar Gul, Ozcan Karatas, Hamit H. Alp, Ihsan B. Cam, Nurcan Ozakar-Il ...
    Type: research-article
    2019 Volume 61 Issue 2 Pages 351-357
    Published: 2019
    Released: June 18, 2019
    JOURNALS FREE ACCESS

    The evaluation of the effect of bleaching on monomer release from two composite resins was performed by bleaching two nanohybrid composite resins Filtek Z550 and Tetric N-Ceram using two bleaching products Whiteness HP Maxx and Vivastyle. In total, 20 samples were made from each composite resin from which four groups were fabricated (two for each bleaching product). The samples were stored in a 75% ethanol solution, and the solutions were renewed after 1, 7, and 28 days. The monomer release was analyzed using high performance liquid chromatography. The data were analyzed using repeated measures analysis of variance and least significant difference multiple comparison test (α = 0.05). Monomers were found to be released from both composite resins. The amounts of monomer released were found to decrease over time (P < 0.05); however, the resins were not affected by bleaching, and the released monomers were well below toxic doses.

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  • Kentaro Okamura, Hiroyasu Koizumi, Akihisa Kodaira, Hiroshi Nogawa, Ta ...
    Type: research-article
    2019 Volume 61 Issue 2 Pages 358-363
    Published: 2019
    Released: June 18, 2019
    JOURNALS FREE ACCESS

    The purpose of this study was to evaluate the surface properties and gloss of CAD/CAM composites after toothbrush abrasion testing. Four CAD/CAM composites for molars (Cerasmart 300, Estelite P block, Katana Avencia P block, and KZR-CAD HR3 Gammatheta), one CAD/CAM composite for premolars (Shofu Block HC Hard), and one feldspathic ceramics (Vitablocs Mark II) were assessed. Knoop hardness number, gloss, and surface roughness (Ra, Rz, and Sa) were measured before and after toothbrush abrasion testing. Knoop hardness number values were in the order Vitablocs Mark II > Katana Avencia P block > Estelite P Block > Shofu Block HC Hard > Cerasmart 300 > KZR-CAD HR3 Gammatheta. After testing, the gloss of Estelite P block and KZR-CAD HR3 Gammatheta was greatly decreased and surface roughness was greatly increased. Periodic recall and re-polishing may thus be necessary when these products are used clinically.

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  • Keiko Fujii-Abe, Masahiro Umino, Hiroshi Kawahara, Chika Terada, Kazuh ...
    Type: research-article
    2019 Volume 61 Issue 2 Pages 364-369
    Published: 2019
    Released: June 18, 2019
    JOURNALS FREE ACCESS

    Although in clinical dentistry the major method used for pain relief is oral administration of analgesics, alternative methods are available, such as transcutaneous electrical nerve stimulation (TENS), acupuncture, vibration and conditioned pain modulation (CPM), formerly termed diffuse noxious inhibitory control. The aim of the present study was to investigate the combined effects of non-noxious (TENS) and noxious (CPM) stimuli on postoperative pain after extraction of an impacted wisdom tooth. The study involved 44 patients who were scheduled to undergo impacted wisdom tooth extraction. The patients were randomly allocated into four groups: noxious stimuli, non-noxious stimuli, combined noxious and non-noxious stimuli, and a sham group. On the day after tooth extraction, stimulation procedures for pain relief were performed and changes in the level of perceived pain were scored using a visual analog scale (VAS). The combination of non-noxious and noxious stimuli decreased the VAS scores by 63.7%, indicating a more potent analgesic effect than that in the non-noxious, noxious, and sham groups. This method of analgesia using a combination of non-noxious and noxious stimuli can be applied to patients who are unable to tolerate analgesics, such as those with allergy, hypersensitivity or digestive disorders, and those who are pregnant.

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  • Shinji Okada, Ayano Katagiri, Hiroto Saito, Jun Lee, Kinuyo Ohara, Tos ...
    2019 Volume 61 Issue 2 Pages 370-378
    Published: 2019
    Released: June 18, 2019
    JOURNALS FREE ACCESS

    Peripheral nerve injury can induce neuroplastic changes in the central nervous system and result in neuropathic pain. This study investigated functional involvement in dorsal paratrigeminal nucleus (dPa5) and nucleus tractus solitarii (NTS) neurons projecting to the parabrachial nucleus (PBN) after trigeminal nerve injury. Anatomical quantification was performed based on phosphorylated extracellular signal-regulated kinase (pERK) expression underlying orofacial neuropathic pain associated with infraorbital nerve chronic constriction injury (ION-CCI) in rats. ION-CCI rats exhibited heat and mechanical hypersensitivity in the ipsilateral upper lip. After injection of retrograde tracer fluorogold (FG) into the contralateral PBN, ION-CCI rats received capsaicin or noxious mechanical stimulation to the upper lip. The total number of FG-labeled neurons in dPa5 and NTS did not change after ION-CCI, and pERK expression in dPa5 did not differ between sham and ION-CCI rats. In the NTS contralateral to ION-CCI, the number of pERK-immunoreactive neurons and percentage of pERK-immunoreactive FG-labeled PBN projection neurons were increased after capsaicin stimulation in ION-CCI rats. The present findings suggest that enhanced noxious inputs from the NTS to the PBN after trigeminal nerve injury modulates PBN neuron activity, which accompanies the affective components of orofacial neuropathic pain.

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