Hiroyuki Karibe

Evaluation of the ion-releasing and recharging abilities of a resin-based fissure sealant containing S-PRG filler.

We evaluated the concentration of fluoride release at the initial stage and after recharging the fluoride from a resin-based sealant containing surface reaction-type pre-reacted glass-ionomer (S-PRG) filler and conventional resin-based sealants. The concentration of other ions released from the sealants in the surrounding distilled water was also examined. At the initial stage, fluoride was released from all sealants. For the sealant containing S-PRG filler, a significantly higher amount of Sr and B ions was detected relative to those from other sealants. After sealant samples were soaked in a sodium fluoride solution, a significant amount of fluoride and other ions was released from the sealant containing S-PRG filler. These findings suggest that sealants containing S-PRG filler enhance the enamel demineralization-inhibiting effect and the remineralization-promoting effect for long-term dental care.

Career choice and attitudes towards dental education amongst dental students in Japan and Sweden

The purpose of this study was to identify and compare the perspectives of dental students towards their career choice and dental education in Japan and Sweden. One hundred and fourteen dental students from the Nippon Dental University, Japan and 43 dental students from the Karolinska Institutet, Sweden participated in this study. Information was derived from a self-answered questionnaire consisting of five items for career choice and six items for dental education. Chi-square test and Wilcoxon signed-rank test were used for comparison. Significant differences were detected for 10 questionnaire items between the two countries. Regarding motivation towards the career choice, 44% of Swedish students indicated interpersonal motives related to helping other people, whereas 32% of Japanese students indicated expectations of their family in the dental profession. As future career options, 64% of Japanese and 47% of Swedish students planned to work as general dentists. More Swedish students (37%) preferred specialisation than Japanese students (17%). Nearly three-quarters of the Swedish students were satisfied with the teaching faculty of their school, whilst only 32% of the Japanese students indicated content. The perspectives of dental students were different in Japan and Sweden. This study provides a description of the perspectives of Japanese and Swedish dental students and enables better understanding of career decision and dental curriculum issues.

Prevalence and association of self-reported anxiety, pain, and oral parafunctional habits with temporomandibular disorders in Japanese children and adolescents: a cross-sectional survey

BackgroundAssociations between temporomandibular disorder (TMD) and psychological variables, pain conditions, and daily activities have been reported more commonly in middle-aged individuals than in children. However, to determine factor-specific preventive programs for TMD, it is important to evaluate the associations between multiple factors and TMD symptoms during childhood. The aim of this study was to assess the relationship between TMD symptoms and other orofacial pain conditions, daily activities, and trait anxiety in a population-based cross-sectional survey of Japanese children and adolescents.MethodsA total of 1,415 subjects (11–15 years old) self-reported their TMD symptoms, headache, neck pain, and toothache, and completed questionnaire scales that assessed 15 daily activities. Trait anxiety was assessed using the State Trait Anxiety Inventory for Children-Trait (STAIC-T) scale. Subjects were dichotomized into a TMD group or control group, based on whether they reported at least 1 TMD symptom: the TMD group (≥1 TMD symptom, nu2009=u2009182) and the control group (no TMD symptoms, nu2009=u20091,233). Data were analyzed using the chi-square test and multivariate logistic regression analysis.ResultsThe prevalence rates for headache and neck pain were significantly higher in the TMD group than in the control group (44.0% vs. 24.7% and 54.4% vs. 30.0%, respectively; both Pu2009<u20090.001). The odds ratios for TMD symptoms in subjects with neck pain and frequent diurnal clenching were 2.08 (Pu2009<u20090.001) and 3.69 (Pu2009=u20090.011), respectively. Moreover, high STAIC-T scores were weakly associated with TMD symptoms.ConclusionsIn this young Japanese population, TMD symptoms were associated with other orofacial pain conditions, particularly neck pain, although they were only weakly associated with trait anxiety. Diurnal clenching was strongly associated with TMD symptoms. Health professionals should carefully consider these factors when developing appropriate management strategies for TMD in children and adolescents.

Reproducibility of Visual Analog Scale (VAS) Pain Scores to Mechanical Pressure

Abstract This study tested the reproducibility of visual analog scale (VAS) pain scores to measure changes in masseter muscle pain evoked by maximally tolerable mechanical stimulation over a short time period in healthy subjects. This study also evaluated gender differences in reproducibility of VAS scores to mechanical stimulation. Ten healthy female and eight healthy male individuals participated in this study. The recordings of VAS pain scores to an identical mechanical pressure on the masseter muscle were performed at three different sessions (T1, T2, and T3). The subjects rated their pain on a VAS to a maximally tolerable stimulus that was recorded on an algometer at the first session. The algometer pressure reading was recorded for each subject and then used to duplicate the same identical mechanical stimulus at each of the three sessions. This identical pressure was repeated in the same marked spot at six minutes and after 30 minutes. The subjects rated the pain on a VAS to this identical stimulus at each session. There was no significant difference in VAS pain scores of all subjects at T1, T2, and T3. There was no significant difference in reproducibility of VAS pain scores in females compared to males. Intraclass correlation coefficients were 0.811 on the right masseter and 0.844 on the left masseter. VAS pain scores to mechanical stimulation were reproducible over a short time period. Gender did not affect the reproducibility. This previously unreported method of measuring pain to repeated identical mechanical stimulation appears to have potential for both clinical and research application.

TMD prevalence in rural and urban Native American populations.

ABSTRACT The purpose of this study was to assess the prevalence of TMD in a consecutive sample of 102 subjects from the Native American population living in an urban setting and 90 subjects living in a rural setting. The study utilized a clinical examination and standardized questionnaires. The sample age ranged from five to 84 years of age. The subjects were asked to estimate pain frequency, severity and daily pattern of jaw pain, difficulty in opening, joint clicking, and sleeping problems. Examination was performed on joint, masticatory, and cervical muscles, as well as occlusion. Data was collected and statistically analyzed. Statistically significant differences were found; however, the only statistically significant difference that might have clinical significance was more facial pain in the urban population.

Comparison of Subjective Symptoms of Temporomandibular Disorders in Young Patients by Age and Gender

Abstract The authors assessed the subjective symptoms of temporomandibular disorders (TMDs) in 167 young patients using self-reported forms, with five ratings for pain intensity and six ratings for difficulty in activities of daily living (ADL), to compare TMD symptoms according to gender and three age groups: group 1: 6- to 12-year-olds (juvenile); group 2: 13- to 15-year-olds (early adolescent); group 3: 16- to 18-year-olds (late adolescent). No significant gender differences were found in the symptoms among the groups, except for headache and neck pain in group 3. Pain intensity and tightness in the jaw/face, headache, and neck pain, as well as the ADL-related difficulty in prolonged jaw opening, eating soft/hard foods, and sleeping significantly differed among the groups (p<0.01, Kruskal–Wallis test). Therefore, late adolescent patients with TMDs have higher pain intensity in the orofacial region and greater difficulty in ADL than do early adolescent and juvenile patients with TMDs.

Contribution of phosphoglucosamine mutase to the resistance of Streptococcus gordonii DL1 to polymorphonuclear leukocyte killing

Phosphoglucosamine mutase (GlmM; EC 5.4.2.10) catalyzes the interconversion of glucosamine-6-phosphate to glucosamine-1-phosphate, an essential step in the biosynthetic pathway leading to the formation of the peptidoglycan precursor uridine 5-diphospho-N-acetylglucosamine. We have recently identified the gene (glmM) encoding the enzyme of Streptococcus gordonii, an early colonizer on the human tooth and an important cause of infective endocarditis, and indicated that the glmM mutation in S. gordonii appears to influence bacterial cell growth, morphology, and sensitivity to penicillins. In the present study, we assessed whether the glmM mutation also affects escape from polymorphonuclear leukocyte (PMN)-dependent killing. Although no differences in attachment to human PMNs were observed between the glmM mutant and the wild-type S. gordonii, the glmM mutation resulted in increased sensitivity to PMN-dependent killing. Compared with the wild type, the glmM mutant induced increased superoxide anion production and lysozyme release by PMNs. Moreover, the glmM mutant is more sensitive to lysozyme, indicating that the GlmM may be required for synthesis of firm peptidoglycans for resistance to bacterial cell lysis. These findings suggest that the GlmM contributes to the resistance of S. gordonii to PMN-dependent killing. Enzymes such as GlmM could be novel drug targets for this organism.

Comparison of patients with orofacial pain of different diagnostic categories.

Abstract The authors compared the pain intensity and difficulty experienced in performing activities of daily living (ADL) among 237 patients with orofacial pain. The patients underwent comprehensive examinations and recorded their subjective symptoms on a form (five items for pain intensity and six for ADL-related difficulty). On the basis of the primary diagnosis, the patients were divided into the temporomandibular joint dysfunction (TMJ), myofascial pain (MP), neuropathic pain (NP), and fibromyalgia (FM) groups. The intensity of pain in the jaw/face, tightness in the jaw/face, pain in the neck, and toothache significantly differed among the groups (p<0.01, Kruskal-Wallis test). Compared to other patients, the FM and NP groups reported greater pain intensity, whereas those in the TMJ group reported lesser pain intensity. The ADL-related difficulty was not significantly different among the groups. Thus, compared to pain due to joint-related disorders, myalgic and neuropathic pain seem to be of higher intensity.

Local administration of resveratrol inhibits excitability of nociceptive wide-dynamic range neurons in rat trigeminal spinal nucleus caudalis

Although we recently reported that intravenous administration of resveratrol suppresses trigeminal nociception, the precise peripheral effect of resveratrol on nociceptive and non-nociceptive mechanical stimulation-induced trigeminal neuron activity in vivo remains to be determined. The aim of the present study was to investigate whether local subcutaneous administration of resveratrol attenuates mechanical stimulation-induced excitability of trigeminal spinal nucleus caudalis (SpVc) neuron activity in rats, in vivo. Extracellular single-unit recordings were made of SpVc wide-dynamic range (WDR) neuron activity in response to orofacial mechanical stimulation in pentobarbital-anesthetized rats. Neurons responded to non-noxious and noxious mechanical stimulation applied to the orofacial skin. Local subcutaneous administration of resveratrol (1-10mM) into the orofacial skin dose dependently and significantly reduced the mean number of SpVc WDR neurons firing in response to both non-noxious and noxious mechanical stimuli, with the maximal inhibition of discharge frequency in response to both stimuli being seen within 5min. These inhibitory effects were no longer evident after approximately 20min. The mean magnitude of inhibition by resveratrol (10mM) of SpVc neuron discharge frequency was almost equal to that of the local anesthetic 1% lidocaine (37mM). These results suggest that local injection of resveratrol into the peripheral receptive field suppresses the excitability of SpVc neurons, possibly via inhibition of Na(+) channels in the nociceptive nerve terminals of trigeminal ganglion neurons. Therefore, local subcutaneous administration of resveratrol may provide relief of trigeminal nociceptive pain, without side effects, thus contributing to the suite of complementary and alternative medicines used as local anesthetic agents.

Regional cerebral blood flow in patients with orally localized somatoform pain disorder: a single photon emission computed tomography study

Aim:u2002 Somatoform pain disorder is characterized by persistent and chronic pain at one or more sites without an associated general medical condition and in which psychological factors are thought to play a role. This study aimed to investigate the pathological features of somatoform pain disorder localized to the oral region by single photon emission computed tomography (SPECT).