Innate immunity is the first line of host defense and represents inherited resistance to infection. Innate immunity works through toll-like receptors (TLRs), which recognize the conserved molecular patterns on pathogenic bacteria known as pathogen-associated molecular patterns. The periodontium is a unique environment in which oral microorganisms are in constant contact with the host immune system. The TLRs present on gingival epithelial cells are continuously stimulated, resulting in production of cytokines and defensins that help to maintain oral health. If the epithelial barrier is breached, allowing invasion of bacteria into the underlying connective tissue, the TLRs on other resident and non-resident cells of the periodontium become activated. This leads to an exaggerated release of pro-inflammatory cytokines and other biological mediators, which may cause host tissue destruction. The present review examines the role of TLRs and their signaling in periodontal health and disease. (J Oral Sci 53, 263-271, 2011)
The aim of this paper was to review in vitro and in situ studies that directly compared the use of bovine teeth as a substitute for human teeth in dental experiments. A PubMed search was conducted for papers published from 1953 to December 30, 2010 using the following keywords: “human bovine enamel” or “human bovine dentin” or “human bovine teeth”. The abstracts of the studies resulting from the keyword search were read, and all papers that compared human and bovine teeth were fully read. Only original articles written in English and directly comparing human and bovine substrates were included in the review. The search was supplemented by manual searches of the reference lists from each identified paper. Out of 76 studies initially selected, 68 fulfilled the selection criteria for inclusion. The studies covered seven categories: dental morphology, chemical composition, physical properties, dental caries, dental erosion/abrasion, bonding/adhesive strength, and marginal microleakage. Inconsistent data exist regarding whether bovine teeth can be considered an appropriate substitute for human teeth in dental research. Morphological, chemical compostion and physical property differences between the two substrates must be considered when interpreting results obtained from any experiment using bovine tooth substrate. (J Oral Sci 53, 273-282, 2011)
This study evaluated the effects of polishing on surface roughness, gloss, and color of regular, opaque, and enamel shades for each of three resin composites. Two-mm-thick resin disks made with Estelite Σ Quick, Clearfil Majesty, and Beautifil II were final polished with 180-, 1000-, and 3000-grit silicon carbide paper. Surface roughness, gloss, and color were measured one week after curing. Estelite Σ Quick had significantly lower roughness values and significantly higher gloss values as compared with Clearfil Majesty and Beautifil II. The effects of surface roughness and gloss on color (L*a*b*) differed among resin composites and by shade. Correlation coefficients between surface roughness and L*a*b* color factors were generally high for Clearfil Majesty, partially high (i.e., between roughness and L*) for Beautifil II, and low for Estelite Σ Quick. Correlation coefficients between gloss and L*a*b* color parameters were generally high for Beautifil II and low for Estelite Σ Quick and Clearfil Majesty. However, for all resin composites, the values of the color differences between 3000-grit and 180-grit polishing groups for all shades were imperceptible by the naked eye. (J Oral Sci 53, 283-291, 2011)
Periodontal infections, which serve as a reservoir of inflammatory mediators such as prostaglandin E2 (PGE2), may pose a threat to the fetal-placental unit and cause preterm delivery. This study was conducted to estimate the levels of PGE2 in gingival crevicular fluid (GCF) and serum to explore the possible use of the GCF-PGE2 level as a risk predictor of preterm low birth weight (PLBW). Twenty-two pregnant female patients were selected for the study. Samples of GCF and serum were collected from each patient, and sampling was repeated at one month after parturition. The level of PGE2 in GCF and serum was estimated using a commercially available ELISA kit (NeogenTM). The mean serum PGE2 level was 4.4 ng/ml and 1.64 ng/ml before and after parturition, respectively, and the difference was statistically significant (P < 0.001). The mean GCF-PGE2 level was 5.8 ng/ml and 5.5 ng/ml before and after parturition, respectively, but the difference was not significant. There was positive correlation between the serumPGE2 and GCF-PGE2 levels, and there was a negative correlation between PGE2 level and gestational age. The present findings suggest that there is a weak correlation between maternal GCF-PGE2 level and birth outcome. Further clinical trials with a larger sample size are warranted for further investigation of the association between GCF-PGE2 level and PLBW. (J Oral Sci 53, 293-300, 2011)
Using tensile tests, this study investigated differences in the welding strength of casts of cobalt-chromium and gold alloys resulting from changes in the voltage and pulse duration in order to clarify the optimum conditions of laser irradiation for achieving favorable welding strength. Laser irradiation was performed at voltages of 150 V and 170 V with pulse durations of 4, 8, and 12 ms. For cobalt-chromium and gold alloys, it was found that a good welding strength could be achieved using a voltage of 170 V, a pulse duration of 8 ms, and a spot diameter of 0.5 mm. However, when the power density was set higher than this, defects tended to occur, suggesting the need for care when establishing welding conditions. (J Oral Sci 53, 301305, 2011)
Brazilian immigrants comprise the third largest ethnic group within the Japanese population. The aim of this cross-sectional study was to determine the factors associated with the prevalence of dental caries in Brazilian schoolchildren living in Japan. A total of 378 schoolchildren, aged between 6 and 14 years, attending Brazilian schools in Japan were included. Clinical data were collected according to World Health Organization criteria. Socioeconomic data, oral health behavior and diet information were collected through questionnaires. The correlation between associated factors and dental caries prevalence was analyzed using chi-square test and multiple logistic regression analysis. The percentage of caries-free schoolchildren was 61.90% and the mean DMFT was 1.28 ± 2.22 (mean ± SD). The mother’s educational level and previous access to dental care services in Brazil were strongly associated with caries experience (P < 0.05). This study indicated that these variables are risk factors associated with caries experience in a community of Brazilian schoolchildren residing in Japan. (J Oral Sci 53, 307-312, 2011)
Since 1972, community water fluoridation programs have not been practiced in Japan. Risk perception among the population plays an important role in the implementation of water fluoridation programs. The oral health behavior of Japanese children has changed, especially due to recent increases among children in the use of fluoridated products and fluoride applications by dentists. The purpose of this study was to examine the associations between oral health behavior, risk perception, and the desire to implement water fluoridation among Japanese residents. We distributed a questionnaire survey (response rate: 92.8%) to mothers with children aged two or three years (n = 573). There was a correlation between anxiety and level of motivation to implement water fluoridation (Spearman coefficient: 0.355, P < 0.001). Exposure to various fluoride experiences was higher in the “not anxious” group. The motivation level was significantly higher in subjects who had a better understanding of the effectiveness of fluoride, those who used fluoride tooth paste, and those whose children received fluoride applications from dentists. We conclude that increased knowledge of and experience with fluoride might help decrease the perception of risk and increase motivation for implementing water fluoridation among the general public. (J Oral Sci 53, 313-319, 2011)
It is unclear whether temporomandibular joint (TMJ) injections with local anesthetic and corticosteroid are an effective first-line management modality for patients with limited mouth opening. The purpose of this study was to determine the effectiveness of TMJ injections in patients with disc displacement without reduction (DDWOR), i.e. closed lock, at the University of Southern California Orofacial Pain and Oral Medicine Center. A retrospective chart review was conducted using a database of over 4000 patient records from 2003-2010. We identified 17 patients (16 female; 1 male) between the ages of 16 and 70 years who had been diagnosed with DDWOR and received a TMJ injection. Active mouth opening before injection ranged between 15 and 40 mm (average 29 mm), and active mouth opening after injection and manual mobilization ranged between 25 and 50 mm (average 39 mm). The average increase in mouth opening after injection and manual mobilization was 10 mm (P = 0.0004). TMJ injection with corticosteroid and local anesthetic is suitable as an alternative first-line management modality for DDWOR. (J Oral Sci 53, 321-325, 2011)
Differential expression of members of the connexin (Cx) gap junction multigene family permits formation of gap junctions with the varied physiological properties required by different tissues. The aim of this study was to characterize connexin expression and the influence of all-trans-retinoic acid (RA) in mouse gingival epithelial cells (GE1). The cells were treated with RA, and expression of Cxs was analyzed by immunofluorescence, reverse transcriptase-polymerase chain reaction (RT-PCR), and real-time PCR. RT-PCR revealed that GE1 cells expressed mRNA for Cx26, Cx30.3, Cx31.1, Cx32, and Cx43. In addition, real-time PCR revealed that RA significantly decreased expression of Cx31.1 as compared with control. These results indicate that GE1 cells are useful in analyzing the expression of connexin molecules in oral keratinocytes from oral mucosal lesions. (J Oral Sci 53, 327-332, 2011)
A study was conducted to compare the mean testosterone and bone mineral density (BMD) levels in men with and without tooth loss. Two hundred three male subjects aged 30-65 years satisfying the study criteria were selected and then examined for bone mineral density, testosterone level, clinical attachment loss, probing pocket depth, tooth mobility and tooth loss due to periodontal disease. Statistical analysis was performed using the Statistical Package for Social Sciences (version 15.0) (SPSS Inc., Chicago, Ill, USA), and differences were considered to be significant at P < 0.05. Independent sample “t” test was used to compare the results, and receiver-operator curve (ROC) analysis was performed to obtain the cut-off. The mean testosterone level in subjects without tooth loss was 4.41 ± 2.57, whereas that in subjects with tooth loss was 2.79 ± 1.15 (P = 0.001). The mean BMD in subjects without tooth loss was 0.99 ± 0.13, whereas that in subjects with tooth loss was 0.96 ± 0.12 (P = 0.046). The testosterone level and BMD in subjects with tooth loss were significantly lower than those in subjects without tooth loss. Testosterone is a good predictor of tooth loss, but its efficiency decreases with increasing tooth loss. BMD is not a good predictor of tooth loss. (J Oral Sci 53, 333-339, 2011)
Dental pain, anxiety and fear are important factors that prevent patients from seeking dental care. In this study, we aimed to evaluate the pain perception of patients during scaling and its relationship with dental anxiety. One hundred dental patients participated in the study. Pain levels after scaling were assessed with a Visual Analog Scale (VAS) and an Anxiety Questionnaire consisting of seven questions. The mean VAS score for the entire study group was 17.3 ± 13.8 with no statistically significant differences between gender and different age groups. The mean anxiety score was 11.66 ± 4.17. This was significantly higher in women (P = 0.005), but there were no statistically significant differences between different age groups. There was a statistically significant correlation between VAS and total anxiety score (P < 0.001) as well as each question, except for questions number 3 and 4 in men. Patients were found to experience only limited pain during scaling. They were anxious because they expected pain, women being more anxious than men. Hence, dentists should seek to alleviate or reduce pain and anxiety related to treatment not only to successfully complete the treatment, but also to sustain and carry the patients into successful maintenance and patient recall. (J Oral Sci 53, 341-348, 2011)
A randomized clinical trial was performed to evaluate the efficacy of three treatment options, including anterior positioning splint therapy, physical therapy, and physical therapy in addition to splint therapy, in terms of treatment outcome, in patients with painful temporomandibular joint clicking. Sixty patients suffering from acute pain and dysfunction were divided randomly into three treatment groups. Twenty patients underwent anterior positioning splint therapy (group I), 20 patients received solely physical therapy (group II), and 20 subjects received physical treatment in addition to splinting (group III). All patients were examined before and after the treatment using a visual analogue scale (VAS) and digital palpation of joint sounds. The data were analyzed using the Kruskal-Wallis, one-way ANOVA and Tukey tests at a significance level of P < 0.05. In comparison with the baseline, subjective pain was decreased significantly (P < 0.05) in all three groups. A significant difference was observed between groups I and II (P <0.05), whereas no significant difference was detected between groups II and III. Six patients in group III did not continue the treatment after physical therapy. The numbers of pain-free patients were 12 in group I, 5 in group II and 9 in group III. We observed a reduction in the frequency of joint sounds across the entire sample (P < 0.05). Anterior positioning splint therapy appears to be the best treatment method for reduction of pain and joint sounds in patients with TMD, compared with the other two methods studied. (J Oral Sci 53, 349-354, 2011)
This in vitro study was performed to evaluate the effect of a diode laser and common disinfectants used in combination on mono-infected dental canals. One hundred and six single-rooted human premolars were prepared and contaminated with Enterococcus faecalis. After two weeks of incubation, samples were divided into two experimental groups (n = 48) and two control groups (n = 5). In the first group, the teeth were rinsed for 5 min with either sterile saline, 2.5% NaOCl, or MTAD, or for 1 min with 2% chlorhexidine gluconate (CHX). In the other group, samples were additionally irradiated with a 810-nm diode laser at 2 W output for 5 × 5 s. Intracanal bacterial sampling was done, and the samples were plated to determine the CFU count. In the first group, 2.5% NaOCl was as effective as 2% CHX and significantly more effective than MTAD (P < 0.008). In the second group, either MTAD, 2% CHX or 2.5% NaOCl in combination with laser treatment had a similar effect. Absence of growth was seen only for MTAD plus laser treatment. Complete elimination of E. faecalis was seen only for the combination of MTAD with diode laser irradiation. Combination therapy with MTAD irrigation and diode laser irradiation, within the parameters used in this study, can be recommended as an effective treatment option for complete elimination of E. faecalis from the root canal system. (J Oral Sci 53, 355-360, 2011)
Odontogenic cysts constitute a major part of oral pathological lesions, but little is known about their distribution patterns in various populations. In this retrospective study, patient records from the archive of the Department of Oral and Maxillofacial Pathology at the Faculty of Dentistry affiliated to the Tehran University of Medical Sciences were reviewed. Cases diagnosed as odontogenic cyst from 1987 to 2007 were selected and histopathologically re-evaluated to confirm the diagnosis. Patients’ demographic information (age and sex) and location of the lesion were recorded and analyzed using descriptive statistics. From a total of 8529 files reviewed, the diagnosis of odontogenic cyst was confirmed in 1227 cases (14.4%). The overall male to female ratio was 1.33:1. The patients’ age ranged from 3 to 84 years with a mean of 28 years. 49% of cysts were found in maxilla and 50.4% in mandible. Radicular cyst was the most common type followed by dentigerous cyst, odontogenic keratocyst, residual cyst and paradental cyst. Lateral periodontal cyst, eruption cyst, glandular odontogenic cyst and gingival cyst of adults were also reported. The distribution pattern of odontogenic cysts in Iran is relatively similar to that in other parts of the world. The importance of complete clinical reports for final diagnosis of these lesions and routine follow-up examinations is emphasized. (J Oral Sci 53, 361-367, 2011)
The aim of this study was to test the efficiency of an extended model of the theory of planned behavior (TPB) in predicting intention to improve oral health behaviors. The participants in this cross-sectional study were 153 first-year medical students (mean age 20.16, 50 males and 103 females) who completed a questionnaire assessing intentions, attitudes, subjective norms, perceived behavioral control, oral health knowledge, and current oral hygiene behaviors. Attitudes toward oral health behaviors and perceived behavioral control contributed to the model for predicting intention, whereas subjective norms did not. Attitudes toward oral health behaviors were slightly more important than perceived behavioral control in predicting intention. Oral health knowledge significantly affected affective and cognitive attitudes, while current behavior was not a significant predictor of intention to improve oral health behavior. The model had a slightly better fit among females than among males, but was similar for home and professional dental health care. Our findings revealed that attitude, perceived behavioral control, and oral health knowledge are predictors of intention to improve oral health behaviors. These findings may help both dentists and dental hygienists in educating patients in oral health and changing patients’ oral hygiene habits. (J Oral Sci 53, 369-377, 2011)
We estimated the prevalence of oral lesions associated with human immunodeficiency virus (HIV-OLs) before and during the antiretroviral therapy (ART) era. The first period was 1997, when many patients received two types of antiretroviral (ARV) drugs. The second study period was 2004 through 2008, when all patients were treated with ART (a combination of two or three classes of drugs, including protease inhibitors). A total of 148 and 388 seropositive participants were examined in 1997 and 2004-2008, respectively. The evaluation consisted of anamnesis and physical examination. The prevalence of HIV-OLs decreased between 1997 (60.1%) and 2004-2008 (29.9%). The HIV-OL responsible for the greatest reduction in prevalence between the two periods was oral candidiasis, of which erythematous candidiasis was the clinical form that decreased most, followed by pseudomembranous candidiasis. In conclusion, we observed a significant reduction in HIV-OLs, which was closely associated with the use of ART. In addition, among patients with a clinical diagnosis of AIDS, we confirmed a significant reduction in HIV-OL prevalence between 1997 and 2004-2008. (J Oral Sci 53, 379-385, 2011)
The aim of this research was to evaluate the effect of individual metallic elements within experimental Au-Pt-based metal-ceramic alloys on in vitro biocompatibility. A binary Au-10 at.% Pt alloy (AP10) was designed as a parent alloy. Six ternary AP10-X (X = In/Fe/Sn/Zn) alloys and four quaternary (AP10-In2)-Y (Y = Fe/Sn/Zn) with different compositions were cast into square plates with size 10X10X0.5 mm3 and subjected to porcelain-firing thermal cycling. A commercial alloy was used as a control. In vitro biocompatibility was investigated using L929 murine aneuploid fibrosarcoma cell line. The test samples and cells were incubated at 37°C in a 5% CO2 atmosphere for 72 h. Alamar™ Blue Assay was carried out to determine the respiratory viability of cultures maintained in the presence of the different materials. The cell only control showed significantly higher levels of cell viability than all six of the ternary alloys and two of the four quaternary alloys, (AP10-In2)-Zn2.1 and (AP10-In2)-Sn1.0 (P < 0.05). The quaternary alloys showed slightly higher levels of cell viability than the ternary alloys, with the exception of AP10-Sn0.9. No statistical differences were seen between the ternary and quaternary alloy groups. Acceptable cell viability was observed on the surfaces of all the alloys. (J Oral Sci 53, 387-391, 2011)
This study investigated the quality of root-end filling in cases of periapical lesions persisting after endodontic surgery. Ten patients requiring extraction of an endodontically treated tooth were included. The root-ends of extracted teeth were examined by scanning electron microscopy. Defects at the interface between the root-end filling and cavity margin were classified as ideal, imperfect (some marginal disruption) or inadequate (continuous marginal disruption involving >30% of the interface). Four cases were scored as imperfect, and six were scored as inadequate. A defective apical seal could favour continuous leakage of surviving bacteria and their by-products from the infected root canal system to periapical tissues, thereby sustaining inflammation. (J Oral Sci 53, 393-396, 2011)
External invasive resorption is an uncommon but aggressive type of external resorption. This report outlines the management of an advanced case of external invasive resorption with mineral trioxide aggregate (MTA). The clinical and radiographic follow-up after 60 months revealed a functional tooth with a stable periodontal condition and no evidence of any further resorption. (J Oral Sci 53, 397-401, 2011)
Hyperdontia is a developmental anomaly that is hypothesized to arise from multiple causes. Supernumerary teeth may remain embedded in the alveolar bone or can erupt into the oral cavity. When such teeth remain embedded, they may cause disturbances to developing teeth. Erupted supernumerary teeth can cause aesthetic or functional problems, especially when situated in the maxillary anterior region. Before a definitive diagnosis and treatment plan can be developed, it is essential to clinically and radiographically enumerate and identify supernumerary teeth. Supplemental central incisors are rare and bilateral cases are even rarer: only five cases have been reported in the literature to date. We describe a case of bilateral supplemental maxillary central incisors and discuss the management of supernumerary teeth. (J Oral Sci 53, 403-405, 2011)
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