Journal of Oral Science
Online ISSN : 1880-4926
Print ISSN : 1343-4934
ISSN-L : 1343-4934
Current issue
January
Showing 1-27 articles out of 27 articles from the selected issue
Review
  • Bodil Lund, Mattias Ulmner, Tore Bjørnland, Trond Berge, Heming Olsen- ...
    Type: review-article
    2020 Volume 62 Issue 1 Pages 1-8
    Published: 2020
    Released: January 29, 2020
    JOURNALS FREE ACCESS

    Temporomandibular joint (TMJ) disease classification and subsequent treatment selection are highly debated subjects within dentistry and medicine. Several suggestions for diagnostic classification and treatment algorithms have been proposed thus far without achieving a clear gold standard. A universally accepted diagnostic classification is essential for therapeutic decision-making as well as a prerequisite for prognostic evaluation and is necessary for achieving research results that are reproducible, comparable, relevant, and applicable in the clinical setting. Often, problems of the TMJ are viewed as mere symptoms or as a syndrome-like group of conditions, without clear demarcation, impeding individualized treatment planning. A Scandinavian group of experienced TMJ surgeons participated in an iterative, structured group discussion process in accordance with the Delphi method, aiming to produce recommendations for a standardized patient clinical evaluation in relation to TMJ dysfunction. Guided by this standardized evaluation, a disease-focused and simplified diagnostic classification scheme is herein suggested.

    Download PDF (992K)
  • Cornelia Frese, Andreas Zenthöfer, Kerstin Aurin, Kyrill Schoilew, The ...
    Type: review-article
    2020 Volume 62 Issue 1 Pages 9-12
    Published: 2020
    Released: January 29, 2020
    JOURNALS FREE ACCESS

    There are many studies on the homebound and institutionalized elderly; however, few studies focus on centenarians and supercentenarians, i.e., people aged 100 and 110 years, respectively. Due to the demographic changes, the population of centenarians is set to increase more than that of other age groups. Therefore, this article aims to review the available literature regarding how oral health might display in this age group and highlight aspects necessitating further research. Oral health, oral health-related quality of life, saliva, and the oral microbiome were emphasized in this study. Most papers relevant to the research questions were excluded because the mean age of participants was <100 years. Only two papers were found on centenarians’ oral health status and saliva and no studies were found focusing on the oral health-related quality of life or oral microbiome. The reviewed studies demonstrate that centenarians presented with good oral mucosal conditions, dental conditions, and general health. The present literature is insufficient to come to a definite conclusion regarding how aging affects the oral health of centenarians and supercentenarians. The limited available research indicates that centenarians display better oral health than other individuals in their respective birth cohorts.

    Download PDF (892K)
Original article
  • Jui Yen Chen, Asako Kubo, Masamichi Shinoda, Akiko Okada-Ogawa, Yoshik ...
    Type: research-article
    2020 Volume 62 Issue 1 Pages 13-17
    Published: 2020
    Released: January 29, 2020
    JOURNALS FREE ACCESS

    Although xerostomia can cause persistent oral pain, the mechanisms underlying such pain are not well understood. To evaluate whether a phosphorylated p38 (pp38)-TRPV4 mechanism in trigeminal ganglion (TG) neurons has a role in mechanical hyperalgesia of dry tongue, a rat model of dry tongue was used to study the nocifensive reflex and pp38 and TRPV4 expression in TG neurons. The head-withdrawal reflex threshold for mechanical stimulation of the tongue was significantly lower in dry-tongue rats than in sham rats. The numbers of TRPV4- and pp38-immunoreactive cells in the TG were significantly higher in dry-tongue rats than in sham rats. Many TRPV4-IR cells were also pp38-immunoreactive. The number of TRPV1-IR cells was unchanged in the TG after induction of tongue dryness. Local injection of a TRPV4 blocker attenuated tongue mechanical hypersensitivity in dry-tongue rats. Intraganglionic injection of a selective p38 MAP kinase inhibitor eliminated tongue hypersensitivity in dry-tongue rats and suppressed TRPV4 expression in TG neurons. The present findings suggest that TRPV4 activation via p38 phosphorylation in TG neurons is involved in mechanical hypersensitivity associated with dry tongue. These mechanisms may have a role in pain associated with xerostomia.

    Download PDF (1519K)
  • Hidetaka Tsuzuki, Yoko Inamoto, Eiichi Saitoh, Keiko Aihara, Seiko Shi ...
    Type: research-article
    2020 Volume 62 Issue 1 Pages 18-22
    Published: 2020
    Released: January 29, 2020
    JOURNALS FREE ACCESS

    This study used 320-row area detector computed tomography (320-ADCT) to determine whether kinematic swallowing events and bolus movement through the oropharynx are affected by bolus consistency and angle of recline. Fourteen healthy adults (4 men, 10 women; age, 22-90 years) underwent 320-ADCT assessment during three 10-mL barium swallow tests, with honey-thick liquid at 60° recline (60°thick), thin liquid at 60° recline (60°thin), and thin liquid at 45° recline (45°thin). The times of swallowing events were measured and compared among the different tests. Bolus propulsion, onset time of true vocal cord (TVC) closure, and upper esophageal sphincter opening were significantly earlier for 60°thin than for 60°thick. Onset time did not significantly differ between 60°thin and 45°thin; however, greater variability was noted for onset of TVC closure with 45°thin, as the TVC started to close before onset of swallowing in 30% of participants. Modulation of TVC closure depends on bolus transport in different reclining positions. The 45° reclining position elicited pre-swallow TVC closure in some participants, which suggests that excessive recline can increase perceived risk of airway invasion during swallowing.

    Download PDF (2127K)
  • Gen Tanabe, Hiroshi Churei, Takahiro Wada, Hidekazu Takahashi, Motohir ...
    Type: research-article
    2020 Volume 62 Issue 1 Pages 23-27
    Published: 2020
    Released: January 29, 2020
    JOURNALS FREE ACCESS

    Laminated custom-made mouthguards tend to delaminate with use; this is a problem in clinical use. Insufficient bonding strength causes delamination, and bonding strength is strongly affected by heating temperature during lamination. The present study aimed to evaluate the influence of heating temperature on the sheet lamination process. Seven mouthguard sheet products were laminated together at different heating temperatures. To evaluate the bonding strength, a delamination test (n = 6) was performed, and the fracture patterns were inspected visually. To evaluate the shock absorption capability, a falling impact test (n = 5) was performed, and the specimen thicknesses were measured. All recorded values were analyzed using two-way analysis of variance and Tukey’s Honest Significant Difference Test (P < 0.05). The present study confirmed that bonding strength was dependent on heating temperature: In ethylene-vinyl acetate copolymer products, the bonding strength was almost constant at 130°C and above, and it was constant at 110°C and above in polyolefin products. The thickness of every specimen decreased and, in some specimens, the shock absorption capability decreased with increasing heating temperature. The present study concludes that the heating temperature during the sheet lamination process when laminated custom-made mouthguards are fabricated may not be less than 120°C in ethylene-vinyl acetate copolymer products and 110°C in polyolefin products.

    Download PDF (1366K)
  • Sayaka Maruyama, Hirofumi Tsutsumi, Hikaru Izawa, Toshinobu Komuro
    Type: research-article
    2020 Volume 62 Issue 1 Pages 28-31
    Published: 2020
    Released: January 29, 2020
    JOURNALS FREE ACCESS

    This study attempted to determine the minimum number of cells required to conduct DNA analyses effectively. Oral mucosal cells obtained from eight persons were suspended and individually collected by using micromanipulation technique. DNA was extracted and amplified by whole-genome amplification (WGA). Nuclear DNA was extracted to evaluate the feasibility of autosomal short tandem repeat (STR) polymorphism and Y-chromosomal STR polymorphism analyses. Tests were conducted with 20 and 30 cells, to determine the minimum number of cells required for each DNA analysis. Tests with 20 cells were repeated 5 times, to examine reproducibility. When five or 10 cells were used, loci could not be identified for most alleles. Furthermore, DNA polymorphism analyses of a single cell transferred directly to a polymerase chain reaction solution were unsuccessful. The present findings suggest that, in forensic identification, 20 or more cells are required in order to obtain clear results from autosomal and Y-chromosomal STR polymorphism analyses. Furthermore, the feasibility of sample preservation and reexamination was also confirmed by DNA amplification with WGA.

    Download PDF (995K)
  • Kenji Takeuchi, Yuki Noguchi, Yukie Nakai, Toshiyuki Ojima, Yoshihisa ...
    Type: research-article
    2020 Volume 62 Issue 1 Pages 32-35
    Published: 2020
    Released: January 29, 2020
    JOURNALS FREE ACCESS

    This study aimed at determining whether oral health behavior differs between patients regularly checked by male and female dentists. The analysis was based on a cross-sectional survey of 354 Japanese community residents (median age = 54 years; 145 men and 209 women) conducted in a municipality from January to February 2017. Data on demographic characteristics and factors associated with oral health behavior were obtained through self-administered questionnaires. The association between regular dentist gender and patients’ regular dental care check-up and interdental cleaning performance was examined after adjusting for potential confounders. Among respondents, 88.7% and 11.3% reported having male and female regular dentists, respectively. In a multivariate logistic regression model, patients regularly checked by female dentists had an increased likelihood of visiting their dentist for dental care check-up at least once every year (odds ratio [OR] = 2.23, 95% confidence interval [CI] = 1.09-4.55)and using an interdental cleaner (OR = 2.62, 95% CI = 1.03-6.71) compared to those regularly checked by male dentists. Patients regularly checked by female dentists tended to have more preventive oral health behaviors than those regularly checked by male dentists. These findings suggest that dentist gender has important clinical implications for patients’ oral health behavior.

    Download PDF (828K)
  • Minoru Sasaki, Yu Shimoyama, Taichi Ishikawa, Yoshitoyo Kodama, Shihok ...
    Type: research-article
    2020 Volume 62 Issue 1 Pages 36-39
    Published: 2020
    Released: January 29, 2020
    [Advance publication] Released: November 09, 2019
    JOURNALS FREE ACCESS

    Granulicatella adiacens (G. adiacens) and Abiotrophia defectiva (A. defectiva) colonize the oral cavity and form part of the normal flora in the intestinal and genitourinary tracts. As reported previously, the frequency of isolation of G. adiacens from the oral cavity was much higher than that of A. defectiva. However, it has been reported that compared with G. adiacens, A. defectiva was isolated at considerably higher frequencies from the blood of patients with infective endocarditis (IE). Hence, in this study, the in vitro interaction of G. adiacens and A. defectiva strains with host surfaces and biofilm formation was examined to assess whether their different adhesive properties contribute to their associations with oral colonization and IE, respectively. G. adiacens exhibited an increased binding ability to saliva-coated hydroxyapatite beads than A. defectiva following the addition of CaCl2. Furthermore, biofilm formation was observed only for G. adiacens with the use of a polystyrene tube and scanning electron microscopy analysis. Conversely, A. defectiva displayed significantly greater adherence to human umbilical vein endothelial cells and immobilized fibronectin than G. adiacens. These findings suggest that differences in binding properties to host components imply specific binding mechanisms in G. adiacens and A. defectiva, which might mediate selective colonization in the oral cavity or are associated with the pathogenicity of endocarditis.

    Download PDF (1771K)
  • Kosuke Kurahashi, Takashi Matsuda, Yuichi Ishida, Tetsuo Ichikawa
    2020 Volume 62 Issue 1 Pages 40-42
    Published: 2020
    Released: January 29, 2020
    JOURNALS FREE ACCESS

    The purpose of this study was to evaluate the influence of various polishing protocols on the surface roughness of polyetheretherketone (PEEK) and identify an effective polishing method of dental prostheses at the chairside. The PEEK specimens were assigned to seven groups with different protocols: no additional polishing (NT); polishing using a rubber point (C); polishing using “silky shine” (S); polishing using “aqua blue paste” (A); protocol C followed by protocol S (CS); protocol C followed by protocol A (CA); and protocol C followed by protocols S and A (CSA). The surface roughness (Sa and Ra) of the polished surfaces was measured. The surface roughness decreased in the following order of groups: NT, C, S, CS, CSA, CA, and A. In Groups C and S, wide deep pits formed by abrasive grains of SiC paper were observed, whereas only fine linear structures were observed on the surface in other groups. With respect to the polishing protocol of PEEK, clinically acceptable surface roughness was obtained using a soft polishing brush and agent for more than 3 min.

    Download PDF (1681K)
  • Zekeriya Taşdemir, Meryem Etöz, Özge Köy, Damla Soydan, Arzu Alkan
    Type: research-article
    2020 Volume 62 Issue 1 Pages 43-47
    Published: 2020
    Released: January 29, 2020
    [Advance publication] Released: November 09, 2019
    JOURNALS FREE ACCESS

    This study aimed to compare the thickness and elasticity of the masseter muscle between patients with gingivitis and patients with periodontitis. A total of 124 patients (63 gingivitis, 61 chronic periodontitis) were recruited at the start of the study, but only 84 patients were declared as final participants. Patients were divided into two groups: (1) patients suffering from gingivitis and (2) those with generalized chronic periodontitis. Clinical (PI, plaque index; GI, gingival index; PD, probing depth; CAL, clinical attachment loss; and BOP, bleeding on probing scores) and ultrasonographic (thickness and elasticity of the masseter muscle) measurements of periodontitis were performed. There were no significant differences in gender, age, body mass index, education status, income level, or marital status between the two groups (P > 0.05). The mean age ± SD for the gingivitis and periodontitis groups was 39.5 ± 10.8 years and 44.8 ± 8.8 years, respectively. There were significant differences between the two groups in the number of PI, GI, PD, CAL, and BOP scores. There were significant differences between the two groups when thickness of masseter during contraction and at rest was taken into account. The gingivitis group had significantly thicker masseter during both contraction and rest. On the other hand, when the elasticity of the masseter was evaluated, there were no significant differences found between the two groups and two sides for each group. Masseter muscle thickness in the periodontitis group was found to be decreased compared with that in the gingivitis group. Furthermore, loss of periodontal tissues due to periodontitis reduces the masticatory ability.

    Download PDF (1486K)
  • Yasuhiro Namura, Toshiki Takamizawa, Yasuki Uchida, Mizuki Inaba, Daic ...
    Type: research-article
    2020 Volume 62 Issue 1 Pages 48-51
    Published: 2020
    Released: January 29, 2020
    JOURNALS FREE ACCESS

    Although there have been improvements in bracket systems precoated with adhesive, removal of adhesive remnants continues to be problematic. This study compared the hardness and maintainability of precoated adhesive with other commercial adhesives. Knoop hardness values were measured after light- or chemical-induced initial curing, immersion in distilled water at 37°C for 24 h and 1,000 and 10,000 thermal cycles after 24 h. Additionally, the forces required to move brackets by 0.5 mm were measured during bracket positioning, and brackets bonded to bovine enamel were examined by field-emission scanning electron microscopy. The Knoop hardness values of the precoated adhesives were lower than those of commercial resin composite adhesives, and hardness was dependent on the amount of filler in the resin matrix. The ability to maintain the device position may depend on the resin matrix composition. Precoated adhesives with less filler and more matrix material are light curable, and remnant resin may be easily removed.

    Download PDF (2011K)
  • Naoko Adachi, Yasuki Kobayashi
    Type: research-article
    2020 Volume 62 Issue 1 Pages 52-56
    Published: 2020
    Released: January 29, 2020
    JOURNALS FREE ACCESS

    There have been few prospective studies on the relationship between oral health conditions and the development of metabolic syndrome (MetS). This prospective cohort study was performed at a Japanese company over one year. Routine medical health examinations, oral health examinations, and a questionnaire pertaining to education, job type, and health behaviors was administered. Participants aged ≥35 years who had no MetS components at baseline were re-examined after one year. Modified Poisson regression analyses were performed to calculate the relative risks (RRs) associated with oral health variables, including periodontitis, decayed and missing teeth, and decayed, missing, and filled teeth (DMFT) in relation to the development of MetS. Of 152 eligible participants, 136 were re-examined after one year; 30 exhibited one or more newly developed MetS components upon re-examination. Decayed teeth at baseline were significantly associated with development of at least one MetS component (adjusted RR 3.25, 95% confidence interval 1.59-6.63). There were no associations between periodontitis, missing teeth, or DMFT and the development of MetS. The association between decayed teeth and MetS was independent of other risk factors, including age and body mass index; therefore, decayed teeth may be associated with the development of MetS.

    Download PDF (878K)
  • Yu-Yang Li, Bao-Sheng Li, Wei-Wei Liu, Qing Cai, Hao-Yang Wang, Yan-Qu ...
    Type: research-article
    2020 Volume 62 Issue 1 Pages 57-61
    Published: 2020
    Released: January 29, 2020
    JOURNALS FREE ACCESS

    Porphyromonas gingivalis (P. gingivalis) is one of the major pathogenic bacteria of periodontitis or peri-implantitis. P. gingivalis tends to attach to the implant’s neck with the formation of biofilm, leading to peri-implantitis. d-arginine has been shown to have a potential antimicrobial role. In this study, P. gingivalis was cultured in Brain Heart Infusion broth together with d-arginine. After 3 days (inhibition) or 6 days (dissociation), these were characterized using crystal violet (CV) staining for the biofilm, extracellular polysaccharide (EPS) production from the biofilm, and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay for biofilm activation. Furthermore, the P. gingivalis biofilm was observed by scanning electron microscopy (SEM). d-arginine effectively reduced biomass accumulation and promoted dissociation at concentrations of ≥50 mM and 100 mM, respectively. Through CV staining, d-arginine concentrations of EPS production from the biofilm for inhibition and dissociation effects was ≥50 mM and 100 mM, respectively. In addition, d-arginine affected biofilm activation for the corresponding concentrations: ≥60 mM for inhibition and ≥90 mM for dispersal. Under SEM observation, d-arginine changed the P. gingivalis biofilm structure in relatively high concentrations for inhibition or dissociation, respectively. The authors concluded that d-arginine could inhibit the formation of P. gingivalis biofilm and promote the dissociation of P. gingivalis biofilm.

    Download PDF (2576K)
  • Kunihito Matsumoto, Toshihiko Amemiya, Motohiro Ito, Yusuke Hayashi, K ...
    Type: research-article
    2020 Volume 62 Issue 1 Pages 62-66
    Published: 2020
    Released: January 29, 2020
    JOURNALS FREE ACCESS

    This study was performed to develop a new rat model of reduced masticatory activity in order to assess the effect of this reduction on the morphology of the temporomandibular joint (TMJ) over time. Female rats were used, and ovariectomy was performed to simulate aged/postmenopausal status. Twenty-four SD rats aged 6 weeks were divided into four groups: ovariectomy/sham procedure (Ov/S); ovariectomy/reduced masticatory activity (Ov/RMA); non-Ov/S (NO/S); and non-Ov/RMA (NO/RMA). The RMA procedure involved grinding down the edges of the upper and mandibular incisors by about 3 mm and supplying the rats with a powdered diet. The bilateral TMJ was examined by micro-computed tomography at 0, 1, 2, 4, 6, and 8 weeks after the start of RMA. Condylar width was greater in the NO/S group than in the Ov/S group after the 2nd week, showing that ovariectomy reduced the width of the condyle. After the 2nd week, significant differences in condylar width were apparent between the NO/S and NO/RMA groups, and between the Ov/S and Ov/RMA groups. This RMA procedure appeared to provide a good model of reduced masticatory activity. The present findings in female rats suggest that reduction of appropriate mastication activity in the growth period results in poor growth of the mandibular condyle and immediately induces atrophy of the mandibular condyle under conditions simulating aged/postmenopausal status.

    Download PDF (1795K)
  • Reiko Furugen, Koji Kawasaki, Masayasu Kitamura, Takahiro Maeda, Toshi ...
    Type: research-article
    2020 Volume 62 Issue 1 Pages 67-69
    Published: 2020
    Released: January 29, 2020
    JOURNALS FREE ACCESS

    Fetuin-A is a liver-secreted glycoprotein isolated from fetal bovine serum. Recent reports of its several pathological functions suggest an association between fetuin-A and systemic diseases. This study therefore examined the correlation between serum fetuin-A level and periodontal status. Data from 356 middle-aged and elderly adults who underwent health examinations in Goto, Japan, during the period from 2008 through 2010 were analyzed. Systemic and periodontal measurements were recorded, and serum fetuin-A level was determined by using an enzyme-linked immunosorbent assay. Fetuin-A levels for participants with moderate to severe periodontitis were significantly lower than those for participants with no or mild periodontitis. Additionally, fetuin-A level negatively correlated with periodontal clinical attachment loss. Moderate to severe periodontitis was significantly correlated with low serum fetuin-A levels (odds ratio, 1.69; 95% confidence interval, 1.01-2.69) in logistic regression analysis. Low serum fetuin-A level was correlated with worse periodontal status and could thus potentially serve as a marker of periodontitis.

    Download PDF (806K)
  • Ngan G. K. Nguyen, Akira Nishiyama, Masahiko Shimada
    Type: research-article
    2020 Volume 62 Issue 1 Pages 70-74
    Published: 2020
    Released: January 29, 2020
    JOURNALS FREE ACCESS

    The aim of this study was to establish an experimental rat model of temporomandibular joint (TMJ) anterior disc displacement (ADD). A pilot study was conducted to determine the most appropriate surgical protocol. In the main experiment, 40 rats were used. Twenty-four rats were subjected to ADD in the right TMJ, and subsequently thereafter six, nine, and nine rats were sacrificed at 1, 4, and 8 weeks, respectively, for gross evaluation. Twelve rats that underwent a sham operation were equally divided and sacrificed at each of the above time points. Four non-treated control rats were sacrificed at the beginning of the study. TMJ blocks were harvested for radiological and histological assessment. Gross examination showed that 14 rats in the ADD group (58.3%) had anterior displacement of the TMJ disc. In the ADD joints, posterior condylar cartilage thickness decreased during the follow-up period; however, there was no significant difference between the sham-treated and ADD joints, or among the follow-up time points (P > 0.05). The anterior condylar cartilage exhibited obvious qualitative alterations. Radiologic signs of osteoarthrosis appeared after ADD surgery, but this became attenuated with time. The model investigated in this study successfully induced ADD in rats, and should be useful for assessment of progressive changes in the TMJ following ADD.

    Download PDF (2915K)
  • Akiko Ohshima, Rena Nomura, Yurina Nagaya, Eriko Kuze, Saori Kojima, R ...
    Type: research-article
    2020 Volume 62 Issue 1 Pages 75-78
    Published: 2020
    Released: January 29, 2020
    JOURNALS FREE ACCESS

    This cross-sectional study investigated the relationship between Oral Assessment Guide (OAG) scores and malnutrition in newly hospitalized patients. A total of 880 hospitalized adults were enrolled. Hypoalbuminemia was defined as serum albumin less than 3.5 g/dL. Patients with hypoalbuminemia were older (P < 0.001), had a higher prevalence of respiratory diseases (P < 0.01), a higher prevalence of digestive diseases (P < 0.01), a lower prevalence of oral feeding (P < 0.001), a lower body mass index (P < 0.001), and higher OAG scores (P < 0.001) than those without hypoalbuminemia. Multivariate logistic regression analyses showed that the prevalence of hypoalbuminemia was significantly related to age (odds ratio [OR] = 1.05, P < 0.001), absence of oral feeding (OR = 2.72, P < 0.001), presence of respiratory diseases (OR = 2.53, P < 0.01), presence of digestive diseases (OR = 1.64, P < 0.01), and OAG scores (OR = 1.14, P < 0.01). Regarding OAG scores, the OR of hypoalbuminemia was greater in patients with disorders (scores 2 or 3) of swallowing (vs. score 1, OR = 1.83, P < 0.05) and saliva (vs. score 1, OR = 1.51, P < 0.05). There appears to be a positive association between OAG scores and hypoalbuminemia in hospitalized patients.

    Download PDF (810K)
  • Sobia Zafar, Mary P. Cullinan, Bernadette K. Drummond, Gregory J. Seym ...
    Type: research-article
    2020 Volume 62 Issue 1 Pages 79-83
    Published: 2020
    Released: January 29, 2020
    JOURNALS FREE ACCESS

    Bisphosphonate-related osteonecrosis of the jaw (BRONJ) is a serious complication associated with bisphosphonate treatment. Zoledronic acid (ZA) is a commonly used bisphosphonate due to its effectiveness in increasing bone density and reducing skeletal events, with evidence that it alters angiogenesis. Replacement of the mevalonate pathway using geranylgeraniol (GGOH) was studied to determine the effects of ZA on angiogenic gene expression in primary human osteoclasts. Osteoclast cultures were generated from peripheral blood mononuclear cells of three patients using the peripheral blood mononuclear cell isolation. These cells were phenotyped by phase-contrast microscopy, tartrate-resistant acid phosphatase staining, and pit assays. Primary osteoclasts were found to express a number of key angiogenic molecules at very high levels. Gene expression levels for 84 human angiogenic factors were determined using PCR arrays. Three genes with significant fold regulation (FR) in response to ZA were as follows: tumor necrosis factor (FR = +2.57, P = 0.050), CXCL9 (FR = +39.48, P = 0.028), and CXCL10 (FR = +18.52, P = 0.0009). The co-addition of geranylgeraniol with ZA resulted in the significant down-regulation of these three genes along with CCL2, TGFBR1, ENG, and CXCL1. GGOH reversed the gene changes induced by ZA and may offer a promising treatment for BRONJ.

    Download PDF (4077K)
  • Xiuju Liu, Xue Jiang, Tong Xu, Qi Zhao, Song Zhu
    Type: research-article
    2020 Volume 62 Issue 1 Pages 84-88
    Published: 2020
    Released: January 29, 2020
    JOURNALS FREE ACCESS

    The present study investigated the bond strength and aging resistance performance of five resin-based luting agents to zirconia. A total of 100 large blocks (10.0 mm × 10.0 mm × 2.5 mm) and 100 small blocks (4.0 mm × 4.0 mm × 2.5 mm) of zirconia were airborne-particle abraded and randomly divided into five groups: (RelyX Ultimate [RUl]; Panavia F [PF]; Clearfil SA Luting [SAC]; Multilink Speed [MS]; and RelyX Unicem [RUn]). The small blocks were bonded to the large blocks using the resin-based luting agents. Shear bond strengths (SBS) and failure mode were determined before and after 5,000 thermocycles. After being stored in water for 24 h, the SBS were MS > PF > RUl > SAC > RUn (P < 0.05). After 5,000 thermocycles, the SBS were MS > SAC ≈ RUl > PF ≈ RUn (P < 0.05); the SBS of the PF, MS, and RUn groups were lower than that before 5,000 thermocycles (P < 0.01). Adhesive failure, cohesive failure, or mixed failure occurred in the specimens. In general, Clearfil SA Luting, a self-adhesive resin-based luting agent containing 10-methacryloxy decyl diphosphate, had good initial and durable SBS to zirconia and was a better adhesive.

    Download PDF (1435K)
  • Daisuke Nasu, Ayako Uematsu, Satoshi Nakamura, Misa Ishiyama, Tetsuo S ...
    Type: research-article
    2020 Volume 62 Issue 1 Pages 89-92
    Published: 2020
    Released: January 29, 2020
    JOURNALS FREE ACCESS

    The oral hygiene and oral status of children with severe disabilities with both nutritional and respiratory complications who were institutionalized at Karugamonoie (KNI), a facility for children with disabilities, were investigated in this study. Their oral hygiene management was solely dependent on caregivers and nurses at the institution. Thirty children (13 females, 17 males; average age, 7.6 years) who had a tracheotomy and feeding tube (gastrostomy, nasogastric, or jejunostomy feeding tube) were included in the study. As for oral characteristics, poor control of tongue movement, anterior open-bite, abnormal strain of facial muscles, dry mouth, and swallowing dysfunction were found in 63.3%, 63.3%, 13.3%, 20.0%, and 100.0%, of the children, respectively. The mean ± standard deviation Decayed, Missing, Filled Teeth score was 0.13 ± 0.57. The Gingival Index (GI) showed that the children had mild (53.3%) to moderate (46.7%) gingivitis. The Simplified Oral Hygiene Index was excellent in 50.0% of the children, good in 23.3%, fair in 20.0%, and poor in 6.7% of the children. These indices were satisfactory in general except for GI management, which may have been hampered by abnormal oral functions and anterior open-bite. In conclusion, oral hygiene management of children with nutritional and respiratory complications at KNI was shown to be of high quality even without on-site intervention by dental specialists.

    Download PDF (853K)
  • Glynn D. Buchanan, Mohamed Y. Gamieldien, Sheree Tredoux, Zunaid I. Va ...
    Type: research-article
    2020 Volume 62 Issue 1 Pages 93-97
    Published: 2020
    Released: January 29, 2020
    JOURNALS FREE ACCESS

    This cone beam computed tomography (CBCT) study aimed to describe the maxillary premolar anatomy of a South African subpopulation using two classification systems. A total of 601 premolars were evaluated. For each tooth, the root number and canal configurations were described using the classification systems devised by Vertucci (1984) and Ahmed et al. (2017). Correlations between root number and sex were determined using the chi-squared test (P = 0.05). Two roots were present in approximately half of all maxillary first premolars (54.1%, n = 171/316). The majority of maxillary second premolars displayed one root (78.2%, n = 223/285). Single-rooted maxillary second premolars were more common in females (P < 0.05). The Vertucci type IV configuration was most prevalent in the maxillary first premolars. In contrast, maxillary second premolars showed a greater tendency toward Vertucci’s type I configuration. The classification proposed by Ahmed et al. indicated the most prevalent maxillary first premolar configuration to be 2MP B1P1. The most common configuration among the maxillary second premolars was 1 MP1. Diverse root and canal anatomical presentations were found in this subpopulation. Both classification systems adequately describe maxillary premolar anatomy; however, the system proposed by Ahmed et al. may more accurately describe complex teeth.

    Download PDF (1488K)
  • Mari Asami, Manabu Kanazawa, Thuy V. Lam, Khaing M. Thu, Daisuke Sato, ...
    Type: research-article
    2020 Volume 62 Issue 1 Pages 98-102
    Published: 2020
    Released: January 29, 2020
    JOURNALS FREE ACCESS

    This study evaluated marginal bone loss and prosthetic complications associated with single implant-retained mandibular overdentures (1-IODs) with locator attachments. The 1-IOD was placed in the mandibular midline by using a conventional loading protocol in 22 patients with an edentulous mandible. Marginal bone loss at the start of loading and 12 months postoperatively was assessed by radiographic and crestal bone evaluation. The crestal bone was defined as the distance between the customized abutment shoulder and the top of the bone, as indicated by probing. In addition, implant stability quotient and prosthetic complications were recorded. The cumulative implant survival rate was 95.5%. Median implant stability quotient remained greater than 80, and median radiographic bone loss was 0.56 mm. Crestal measurement showed a median crestal bone loss of 0.16, 0.43, 0.39, and 0.52 mm on the buccal, right, lingual, and left sides, respectively. Both radiographic and crestal bone loss values significantly differed between the start of implant loading and 12 months postoperatively (except on the buccal and lingual sides; P < 0.05). The need to replace the nylon insert was the most common complication. Conventional loading of a 1-IOD with a locator attachment resulted in a high survival rate, good implant stability, and acceptable marginal bone loss.

    Download PDF (2632K)
  • Jaqueline C. Favaro, Edgar Ribeiro, Ricardo D. Guiraldo, Murilo B. Lop ...
    Type: research-article
    2020 Volume 62 Issue 1 Pages 103-106
    Published: 2020
    Released: January 29, 2020
    JOURNALS FREE ACCESS

    This study aims to evaluate the effect of mouth rinses on the color, microhardness, and surface roughness of tooth enamel. Sixty dental blocks were collected from human third molars and divided in five groups (n = 12): the control group (CG) without immersion in mouth rinse, Listerine Zero, Colgate Plax Fresh Mint, Listerine Whitening, and Colgate Luminous White. The groups were subjected to initial color analysis; the microhardness and roughness of the enamel surfaces were evaluated. Next, the samples were subjected to immersion in mouth rinses or brushing with conventional fluoride toothpaste (CG) according to the manufacturer’s instructions; after a 12-week treatment, the color, microhardness, and roughness were once again assessed and compared with the initial analysis. Data were tabulated and analyzed through a two-way analysis of variance (ANOVA) (color and roughness) followed by Tukey’s test. Microhardness was analyzed through the Kruskal-Wallis test followed by Dunn’s test; the level of significance was 5%. All groups immersed in mouth rinses had a higher level of microhardness loss than CG; additionally, all groups showed changes in the enamel surface. Enamel surface loss was observed using a roughness test, and the mouth rinses promoted a higher level of color changes than CG. Given the results, it can be concluded that the mouth rinses led to significant changes in tooth enamel.

    Download PDF (811K)
  • Helen Baranto, Carina K. Weiner, Idil A. Burt, Annika Rosén
    Type: research-article
    2020 Volume 62 Issue 1 Pages 107-111
    Published: 2020
    Released: January 29, 2020
    JOURNALS FREE ACCESS

    The self-reported functional outcomes, clinical findings, and results of dental cast analysis before and after orthognathic surgery with surgically assisted rapid maxillary expansion (SARME) using a hybrid rapid maxillary expander (RME) were evaluated. Data were collected from 43 patients who underwent orthognathic surgery with SARME using a hybrid RME between 2001 and 2013. The patients were recruited during a follow-up clinical examination and were required to complete a questionnaire about their opinions and self-reported functional outcomes. Dental casts were used to analyze posttreatment palatal expansion. The mean follow-up time was 68 months (range: 25-135 months). The most common indication for SARME was the presence of a crossbite. Of the 30 patients who underwent a follow-up clinical examination (69.8% answer rate), 4 (13.3%) had symptoms of temporomandibular disorder (TMD), 1 (3.3%) experienced myalgia, and 3 (10.0%) experienced arthralgia on clinical palpation. Cast analysis revealed significant palatal expansion. The intercanine distance, intermolar distance, and palatal height were increased by 3, 5, and 2 mm, respectively. Overall, the patients were satisfied with the preoperative information, improved functions, and aesthetic results. The prevalence of TMD symptoms and other side effects following orthognathic surgery with SARME using a hybrid RME was low, and significant palatal expansions were achieved.

    Download PDF (1440K)
  • Dulguun Batbold, Akiko Kobayashi, Junya Kumagai, Satoshi Yamaguchi, Te ...
    2020 Volume 62 Issue 1 Pages 112-118
    Published: 2020
    Released: January 29, 2020
    JOURNALS FREE ACCESS

    Fifty-four patients diagnosed with paresthesia on one side of the lower lip or skin in the chin area, were examined by multiple sensory tests and assessed self-reported subjective symptoms and the psychological state through questionnaires. Additionally, they were followed over time. Each sensory test threshold was evaluated and classified according to the individual way of scoring system, and the average sensory score (ASS) was used to analyze the correlation between self-reported symptoms and psychological state. On the second visit, all sensory test results had improved. The ASS was positively correlated with the pain questionnaire on the first visit; however, it did not correlate with psychological state or personality. There was a positive correlation between neuroticism and anxiety scores. The index of change (IC) of the ASS over time did not correlate with the IC of patients’ self-reported symptoms or mental state. The IC of ASS data improved in all patients, but self-reported subjective symptoms did not show signs of improvement in all patients. When patients were divided into two groups according to age or sex, older females showed significantly more improvement than younger males on the psychological test.

    Download PDF (1354K)
Short Communication
  • Ignacio Aliaga, Maria Pedrera-Canal, Vicente Vera, Sergio Rico Martín, ...
    Type: Short communication
    2020 Volume 62 Issue 1 Pages 119-121
    Published: 2020
    Released: January 29, 2020
    JOURNALS FREE ACCESS

    The aim of the present study was to analyze the parameters recorded by the Simodont dental trainer and methacrylate block grades during preclinical practicums to validate whether manual skills can be assessed by both methodologies, over a period of two years and to obtain a preclinical evaluation methodology for all the parameters that measure Simodont performance in each of the prepared figures. To this end, the methacrylate block practice’s criteria and evaluation scale were used as predictors. A total of 82 students who completed the first year of dentistry were followed for 2 years. Their performance on the same task (i.e., cavity preparation of three figures in the Simodont and methacrylate blocks) was then reevaluated in the third year. Manual skill improvement was detected in all the students. The parameters measured by the Simodont were used as predictors of the methacrylate block evaluation’s results, performed by a professor. Multiple linear regression models for each of the figures and years evaluated in the study were proposed. The present study demonstrates that both methodologies can detect manual skill improvement in dental students. Additionally, the Simodont practice can be reliably evaluated.

    Download PDF (775K)
Case Report
  • Mamoru Murakami, Yasuhiro Nishi, Takaharu Shimizu, Masahiro Nishimura
    Type: case-report
    2020 Volume 62 Issue 1 Pages 122-124
    Published: 2020
    Released: January 29, 2020
    JOURNALS FREE ACCESS

    Retainers are the most important component in the success of an obturator prosthesis. However, the optimal retainer design for a fully dentulous patient with palatal defect needs four widely separated retainers—resulting in unsatisfactory esthetics—and regulates engagement of deep undercuts of the defect cavity, which leads to an inadequate palatal seal. A new retainer-free obturator prosthesis that closes only the defect cavity and is retained by undercuts within the defect was designed and proved useful for problems caused by a clasp-retained obturator prosthesis for a fully dentulous patient with palatal defects.

    Download PDF (3050K)
feedback
Top