Toshiki Yoneda

Involvement of toll-like receptor 2 and 4 in association between dyslipidemia and osteoclast differentiation in apolipoprotein E deficient rat periodontium

BackgroundDyslipidemia increases circulating levels of oxidized low-density lipoprotein (OxLDL) and this may induce alveolar bone loss through toll-like receptor (TLR) 2 and 4. The purpose of this study was to investigate the effects of dyslipidemia on osteoclast differentiation associated with TLR2 and TLR4 in periodontal tissues using a rat dyslipidemia (apolipoprotein E deficient) model.MethodsLevels of plasma OxLDL, and the cholesterol and phospholipid profiles in plasma lipoproteins were compared between apolipoprotein E-deficient rats (16-week-old males) and wild-type (control) rats. In the periodontal tissue, we evaluated the changes in TLR2, TLR4, receptor activator of nuclear factor kappa B ligand (RANKL) and tartrate resistant acid phosphatase (TRAP) expression.ResultsApolipoprotein E-deficient rats showed higher plasma levels of OxLDL than control rats (p<0.05), with higher plasma levels of total cholesterol (p<0.05) and LDL-cholesterol (p<0.05) and lower plasma levels of high-density lipoprotein cholesterol (p<0.05). Their periodontal tissue also exhibited a higher ratio of RANKL-positive cells and a higher number of TRAP-positive osteoclasts than control rats (p<0.05). Furthermore, periodontal gene expression of TLR2, TLR4 and RANKL was higher in apolipoprotein E-deficient rats than in control rats (p<0.05).ConclusionThese findings underscore the important role for TLR2 and TLR4 in mediating the osteoclast differentiation on alveolar bone response to dyslipidemia.

MicroRNAs in Salivary Exosome as Potential Biomarkers of Aging

The aim of this study was to examine whether salivary exosomal miRNAs could be identified as aging biomarkers. Fifteen young healthy volunteers (median age, 21.0 years) and 13 old individuals (median age, 66.0 years) were recruited. Unstimulated whole saliva was collected, salivary exosomes were isolated, and total RNA was extracted. In a microarray, 242 miRNAs were commonly detected in these two mixed samples. Based on the cut-off values of 2- or 0.5-fold changes (FC) and regulatory power for aging process, six candidate miRNAs (miR-24-3p, miR-371a-5p, miR-3175, miR-3162-5p, miR-671-5p, and miR-4667-5p) were selected. After comparing each total RNA obtained by the 15 young and 13 old individuals to validate the FC values using quantitative real-time PCR, miR-24-3p was identified as a novel candidate aging biomarker. This pilot study suggested that salivary exosomal miRNAs could be identified as candidate aging biomarkers. To confirm whether miR-24-3p in salivary exosomes are suitable biomarkers of aging, further validation research is required.

Relationship between increases in BMI and changes in periodontal status: a prospective cohort study

AIM The purpose of this prospective cohort study was to investigate whether body mass index (BMI) and oral health behaviour are related to changes in periodontal status in Japanese university students. MATERIALS AND METHODS Students (n = 224) who were interested in receiving oral health examinations before entering university and before graduation were included in the analysis. Subjects were investigated regarding the correlations of oral health behaviours and increases in BMI with the percentage of bleeding on probing (%BOP) and Community Periodontal Index (CPI) scores as indicators of changes in periodontal status. RESULTS The risk of increased %BOP was associated with the non-use of dental floss (adjusted odds ratio [OR]: 3.11; 95% confidence interval [CI]: 1.31-7.37; p < 0.05), whereas the risk of increased CPI score was associated with increases in BMI (OR: 1.95; 95% CI: 1.05-3.65; p < 0.05) and simplified oral hygiene index score (OR: 2.28; 95% CI: 1.23-4.22; p < 0.01). CONCLUSION Increases in BMI were associated with worsening of periodontal status, defined as increased CPI score in Japanese university students, whereas lack of inter-dental cleaning was associated with exacerbated gingival bleeding.

Anti-aging Effects of Co-enzyme Q10 on Periodontal Tissues

Oxidative stress is associated with age-related reactions. The anti-oxidative effects of a reduced form of co-enzyme Q10 (rCoQ10) suppress oxidative stress, which may contribute to the prevention of age-related inflammatory reactions. We examined the effects of topically applied rCoQ10 on periodontal inflammatory reactions in a rat aging model. Male Fischer 344 rats, 2 (n = 6) and 4 mos (n = 18) of age, were used. All of the two-month-old rats and 6 of the four-month-old rats were sacrificed and 12 remaining four-month-old rats received topically applied ointment with or without 1% rCoQ10 on the gingival surface until they reached 6 mos of age. The rats showed an age-dependent increase in circulating oxidative stress. RCoQ10 decreased oxidative DNA damage and tartrate-resistant acid-phosphatase-positive osteoclasts in the periodontal tissue at 6 mos of age as compared with the control. The same conditions lowered gene expression of caspase-1 and interleukin-1β in the periodontal tissue. Furthermore, Nod-like receptor protein 3 inflammasomes were less activated in periodontal tissues from rCoQ10-treated rats as compared with the control rats. Our results suggest that rCoQ10 suppresses age-related inflammatory reactions and osteoclast differentiation by inhibiting oxidative stress.

Effects of hydrogen-rich water on aging periodontal tissues in rats

Oxidative damage is involved in age-related inflammatory reactions. The anti-oxidative effects of hydrogen-rich water suppress oxidative damage, which may aid in inhibiting age-related inflammatory reactions. We investigated the effects of drinking hydrogen-rich water on aging periodontal tissues in healthy rats. Four-month-old male Fischer 344 rats (n = 12) were divided into two groups: the experimental group (hydrogen-rich water treatment) and the control group (distilled water treatment). The rats consumed hydrogen-rich water or distilled water until 16 months of age. The experimental group exhibited lower periodontal oxidative damage at 16 months of age than the control group. Although protein expression of interleukin-1β did not differ, gene expression of Nod-like receptor protein 3 inflammasomes was activated in periodontal tissues from the experimental group as compared with the control group. Drinking hydrogen-rich water is proposed to have anti-aging effects on periodontal oxidative damage, but not on inflammatory reactions in healthy rats.

Application of Coenzyme Q10 for Accelerating Soft Tissue Wound Healing after Tooth Extraction in Rats

Accelerating wound healing after tooth extraction is beneficial in dental treatment. Application of antioxidants, such as reduced coenzyme Q10 (rCoQ10), may promote wound healing after tooth extraction. In this study, we examined the effects of topical application of rCoQ10 on wound healing after tooth extraction in rats. After maxillary first molars were extracted, male Fischer 344 rats (8 weeks old) (n = 27) received topical application of ointment containing 5% rCoQ10 (experimental group) or control ointment (control group) to the sockets for 3 or 8 days (n = 6–7/group). At 3 days after extraction, the experimental group showed higher collagen density and lower numbers of polymorphonuclear leukocytes in the upper part of socket, as compared to the control group (p < 0.05). Gene expression of interleukin-1β, tumor necrosis factor-α and nuclear factor-κB were also lower in the experimental group than in the control group (p < 0.05). At 8 days after tooth extraction, there were no significant differences in collagen density, number of polymorphonuclear leukocytes and bone fill between the groups. Our results suggest that topical application of rCoQ10 promotes wound healing in the soft tissue of the alveolar socket, but that rCoQ10 has a limited effect on bone remodeling in rats.

The effects of non-surgical periodontal treatment on glycemic control, oxidative stress balance and quality of life in patients with type 2 diabetes: A randomized clinical trial

Aim The purpose of this study was to investigate the effects of non-surgical periodontal treatment on hemoglobinA1c (HbA1c) levels, oxidative stress balance and quality of life (QOL) in patients with type 2 diabetes mellitus (T2DM) compared to no periodontal treatment (simple oral hygiene instructions only). Methods The design was a 6-month, single-masked, single center, randomized clinical trial. Patients had both T2DM and chronic periodontitis. Forty participants were enrolled between April 2014 and March 2016 at the Nephrology, Diabetology and Endocrinology Department of Okayama University Hospital. The periodontal treatment group (n = 20) received non-surgical periodontal therapy, including scaling and root planing plus oral hygiene instructions, and consecutive supportive periodontal therapy at 3 and 6 months. The control group (n = 17) received only oral hygiene instructions without treatment during the experimental period. The primary study outcome was the change in HbA1c levels from baseline to 3 months. Secondary outcomes included changes in oxidative stress balance (Oxidative-INDEX), the Diabetes Therapy-Related QOL and clinical periodontal parameters from baseline to 3 months and baseline to 6 months. Results Changes in HbA1c in the periodontal treatment group were not significantly different with those in the control group at 3 and 6 months. Systemic oxidative stress balance and QOL significantly improved in the periodontal treatment group compared to the control group at 3 months. In the subgroup analysis (moderately poor control of diabetes), the decrease in HbA1c levels in the periodontal treatment group was greater than that in the control group at 3 months but not significant. Conclusions In T2DM patients, non-surgical periodontal treatment improved systemic oxidative stress balance and QOL, but did not decrease HbA1c levels at 3 months follow-up. Trial registration Current Controlled Trials UMIN-ICDR UMIN 000013278 (Registered April 1, 2014).

Longitudinal relationship between plasma reactive oxygen metabolites and periodontal condition in the maintenance phase of periodontal treatment.

Aim. The present cohort study describes the longitudinal relationship between plasma oxidative status and periodontitis progression during the maintenance phase of treatment. Materials and Methods. Forty-five patients (mean age 58.8 years) were monitored from 2008 to 2013. Periodontal conditions, including probing pocket depth (PPD) and clinical attachment level (CAL), were recorded. Measurements of plasma reactive oxygen metabolites (ROM) and biologic antioxidant potential (BAP) were performed to evaluate plasma oxidative status. The patients were assigned into 2 groups as low and high plasma ROM level using a cut-off value which was median of plasma ROM level at baseline. Results. In the subjects with low plasma ROM level at baseline, changes in mean CAL were positively correlated with changes in plasma ROM levels, bleeding on probing, and plaque control record, but not with PPD. In the subjects with high plasma ROM at baseline, changes in CAL were significantly associated with only PPD at baseline. On the other hands there were no significant associations between changes in CAL and those in plasma BAP levels. Conclusions. When plasma ROM level in periodontitis patients was low, increases in plasma ROM level were associated with those in CAL during the maintenance phase of treatment.

Factors related to the formation of buccal mucosa ridging in university students

Abstract Objective. Buccal mucosa ridging (BMR) is known as a clinical sign of clenching, which is one of the major manifestations of bruxism. However, there are few reports about the formation of BMR and no data regarding the association between BMR and factors such as malocclusion. The purpose of the current study was to investigate the relationship between BMR and factors such as the number of teeth present, gender, body mass index (BMI), occlusion and clenching habit in university students. Materials and methods. A total of 2101 students (1164 males, 937 females), aged 18–29 years old, were included in the study. BMR and the number of teeth present were recorded and malocclusion was defined using a modified version of the Index of Orthodontic Treatment Need. Additional information regarding gender, clenching habit and BMI was collected via a questionnaire. Results. Forty-six per cent of the subjects had BMR and the prevalence of BMR in females was significantly higher than that of males (chi square test, p < 0.001). According to logistic regression analysis, the probability of BMR was significantly associated with female gender (OR = 1.501, 95% CI = 1.259–1.790, p < 0.001), crowding (OR = 2.102, 95% CI = 1.706–2.590, p < 0.001) and overjet (OR = 0.585, 95% CI = 0.418–0.818, p = 0.002). On the other hand, BMR was not associated with awareness of clenching habit and BMI. Conclusions. Gender, crowding and overjet were related to the formation of BMR in university students. When evaluating BMR as a clinical sign of clenching, one might have to take factors such as gender and crowding into consideration.

Association between periodontitis and prognosis of pancreatobiliary tract cancer: A pilot study

Several studies have indicated that periodontitis is a risk factor for cancer. However, the association between periodontitis and the prognosis of pancreatobiliary tract cancer remains unclear. The aim of this pilot study was to investigate the association between periodontitis and prognosis of pancreatobiliary tract cancer. A total of 22 patients diagnosed with pancreatobiliary tract cancer were analyzed. Oral health status, including severity of periodontitis, general health status and biochemical serum markers were evaluated. The Kaplan-Meier method and Cox proportional hazards model were used to assess factors affecting the prognosis of pancreatobiliary tract cancer. The Kaplan-Meier analysis demonstrated that low body mass index, high concentration of serum C-reactive protein (CRP) and severe periodontitis were significant prognostic factors for survival rate. The Cox proportional hazards model revealed that serum carbohydrate antigen 19-9 concentration [hazard ratio (HR)=1.002; 95% confidence interval (CI): 1.000–1.004] and serum CRP concentration (HR=2.57; 95% CI: 1.15–5.74) were significantly associated with the prognosis of pancreatobiliary tract cancer. In addition, cancer patients with severe periodontitis had higher serum CRP concentrations compared with those without severe periodontitis. Therefore, severe periodontitis indirectly affected the prognosis of pancreatobiliary tract cancer through promoting systemic inflammation.