Assessment of bone defect morphology for the adjunctive use of bone grafting combined with enamel matrix derivative: A 3-year cohort study.

BACKGROUND: There have been limited studies with statistically sufficient sample sizes for assessment of suitable bone defect morphology for combination therapy with enamel matrix derivative (EMD) and bone grafting. The aim of this study was to investigate the appropriate feature of intrabony defects, such as bone defect angle (DA) and the containment by bony wall, for yielding the additional benefit of bone grafting in combination with periodontal regenerative therapy using EMD. METHODS: Following periodontal regenerative therapy using EMD with or without autologous bone grafting, 282 intrabony defects of 177 participants were maintained for 3 years. Multilevel linear regression analysis was performed to evaluate the radiographic bony defect depth (RBD) reduction after adjusting for confounders. RESULTS: The baseline parameters, except for the proportion of contained bony defects and tooth mobility, did not differ significantly between the groups with and without bone grafts. There was no significant difference in the improvement of clinical parameters between the groups. The 1- and 3-year reduction of RBD showed significant inverse correlations with preoperative DA only in the group without bone graft. Furthermore, multivariate analysis showed a significant interaction between DA at baseline ≥40° and adjunctive bone grafting in the reduction of RBD, regardless of the number of bony walls. CONCLUSION: Adjunctive autologous bone grafting with enamel matrix derivative might be significantly beneficial for defect depth improvement in the case of DA at baseline ≥40°.

Income-related inequalities in the association of smoking with periodontitis: a cross-sectional analysis in Tokyo Metropolitan Districts.

OBJECTIVE: Socio-economic status (SES) and smoking are risk factors for periodontitis; however, their interaction has not been determined. We investigated the effect of modification of SES and smoking with periodontal conditions. MATERIALS AND METHODS: Data on the social background, smoking status, and dental examination of 1033 individuals residing in the Tokyo Metropolitan District were analyzed. The outcomes were the number of remaining teeth and the proportion of teeth with probing pocket depth (PPD) ≥ 4 mm and ≥ 6 mm. Multilevel linear and Poisson regression analyses were performed after adjusting for possible confounding factors, including SES, assessed by the average income of the residential area. RESULTS: The mean number of remaining teeth was 24.6 ± 4.8, and the proportion of teeth with PPD ≥ 4 mm and ≥ 6 mm was 31.2 ± 28.5% and 12.2 ± 18.1%, respectively. After adjusting for confounding factors, the lowest-income population had significantly lesser teeth (coefficient: - 0.46, 95% CI - 0.89, 0.02, p = 0.039) and a higher proportion of teeth with PPD ≥ 4 mm than the highest-income population (ratio of means: 1.22, 95% CI 1.03-1.44, p = 0.013). Significant interactions were observed; income inequalities in periodontitis were significant only among current smokers. CONCLUSION: Inequality in socio-economic status is associated with oral health inequalities. The adverse effects of smoking on periodontitis might be greater in the low-income population. CLINICAL RELEVANCE: The low-income population, especially current smokers, had significantly more compromised oral health than the high-income population. In addition to the emphasis on smoking cessation, the promotion of universal health coverage for dental care is necessary to reduce oral health inequalities.

Influence of aging on periodontal regenerative therapy using enamel matrix derivative: A 3-year prospective cohort study.

AIM: To investigate the influence of chronological aging on periodontal regenerative therapy (PRT) outcomes with enamel matrix derivative (EMD). MATERIALS AND METHODS: In total, 253 intra-bony defects (151 patients) including 44 furcation involvement were prospectively investigated for 3 years after regenerative therapy with EMD by evaluating probing pocket depth (PPD), clinical attachment level (CAL), and radiographic bone defect depth (RBD). The influence of age on these outcomes was assessed using multilevel regression analyses adjusting for confounders. RESULTS: Participants' mean age was 55.9 ± 12.3 years (range: 22-85). Baseline PPD, CAL, and RBD were 6.14 ± 1.82, 7.22 ± 2.14, and 5.08 ± 2.04 mm, respectively. Significant improvement was observed with PPD reductions of 2.84 ± 1.73 and 2.87 ± 1.87 mm, CAL gains of 2.40 ± 1.87 and 2.47 ± 1.89 mm, and RBD gains of 1.76 ± 1.98 and 2.39 ± 2.41 mm at 1- and 3-year examinations, respectively. At the 1-year examination, multivariate analysis revealed a significant negative association between age and improvement in PPD and CAL (coefficients: -0.13, -0.23 mm per 10 years). However, by the 3-year examination, no significant association was noted between age and improvement in PPD, CAL, or RBD. CONCLUSION: Although the statistical difference was detected with age at 1-year examination, PRT with EMD significantly improved clinical outcomes on long-term observation, irrespective of the patient's age. CLINICAL TRIAL REGISTRATION NUMBER: UMIN000039846.

Association between periodontal inflammation and serum lipid profile in a healthy population: A cross-sectional study.

AIMS: The impact of periodontal inflammation on lipid metabolism is controversial. This study aimed to investigate the association between full-mouth periodontal inflammation and serum lipid levels. MATERIALS AND METHODS: In this cross-sectional study, we performed periodontal and bacteriological examinations during medical checkup on 131 subjects. The association between the periodontal inflamed surface area (PISA) and the lipid markers was analyzed by multiple linear regression, adjusting for age, sex, smoking, and body mass index. RESULTS: Overall, 118 medically healthy participants were analyzed. The proportions of none, mild, moderate, and severe periodontitis were 37.3%, 32.2%, 25.4%, and 5.1%, respectively. Multivariate analysis showed that high-density lipoprotein cholesterol was significantly higher in participants with the lowest tertile of PISA values (PISA low, coefficient: 7.94; 95% confidence interval [CI]: 1.63, 14.26, p = .01) compared to those in other tertiles (PISA high). Low-density/high-density lipoprotein cholesterol and total/high-density lipoprotein cholesterol ratios were significantly lower in the PISA-low group than the PISA-high group (coefficient: -0.26 and -0.30; 95% CI: -0.50, -0.02, and -0.59, -0.0002; p = .04 and .0498). Serum high-sensitivity C-reactive protein level, but not serum Porphyromonas gingivalis antibody titer, partly explained the association between PISA and high-density lipoprotein cholesterol. A significant interaction between female sex and PISA values toward high-density lipoprotein cholesterol level was detected. CONCLUSION: Periodontal inflammation was inversely associated with higher high-density lipoprotein cholesterol, especially in females. Elevated serum C-reactive protein partly explained this association.

Biological effects of Er:YAG laser irradiation on the proliferation of primary human gingival fibroblasts.

We investigated the biological effects of Er:YAG laser (2940-nm; DELight, HOYA ConBio, Fremont, California) irradiation at fluences of 3.6, 4.2, 4.9, 6.3, 8.1 or 9.7 J cm-2 at 20 or 30 Hz for 20 or 30 seconds on primary human gingival fibroblasts (HGFs). Irradiation at 6.3 J cm-2 promoted maximal cell proliferation, determined by WST-8 assay and crystal violet staining, but was accompanied by lactate dehydrogenase release, on day 3 post-irradiation. Elevation of ATP level, Ki67 staining, and cyclin-A2 mRNA expression confirmed that Er:YAG affected the cell cycle and increased the number of proliferating cells. Transmission electron microscopy showed alterations of mitochondria and ribosomal endoplasmic reticulum (ER) at 3 hours post-irradiation at 6.3 J cm-2 , and the changes subsided after 24 hours, suggesting transient cellular injury. Microarray analysis revealed up-regulation of 21 genes involved in heat-related biological responses and ER-associated degradation. The mRNA expression of heat shock protein 70 family was increased, as validated by Real-time PCR. Surface temperature measurement confirmed that 6.3 J cm-2 generated heat (40.9°C post-irradiation). Treatment with 40°C-warmed medium increased proliferation. Laser-induced proliferation was suppressed by inhibition of thermosensory transient receptor potential channels. Thus, despite causing transient cellular damage, Er:YAG laser irradiation at 6.3 J cm-2 strongly potentiated HGF proliferation via photo-thermal stress, suggesting potential wound-healing benefit.

Desensitizing Agent Reduces Dentin Hypersensitivity During Ultrasonic Scaling: A Pilot Study.

BACKGROUND: Dentin hypersensitivity can interfere with optimal periodontal care by dentists and patients. The pain associated with dentin hypersensitivity during ultrasonic scaling is intolerable for patient and interferes with the procedure, particularly during supportive periodontal therapy (SPT) for patients with gingival recession. AIM: This study proposed to evaluate the desensitizing effect of the oxalic acid agent on pain caused by dentin hypersensitivity during ultrasonic scaling. MATERIALS AND METHODS: This study involved 12 patients who were incorporated in SPT program and complained of dentin hypersensitivity during ultrasonic scaling. We examined the availability of the oxalic acid agent to compare the degree of pain during ultrasonic scaling with or without the application of the dentin hypersensitivity agent. Evaluation of effects on dentin hypersensitivity was determined by a questionnaire and visual analog scale (VAS) pain scores after ultrasonic scaling. The statistical analysis was performed using the paired Student t-test and Spearman rank correlation coefficient. RESULTS: The desensitizing agent reduced the mean VAS pain score from 69.33 ± 16.02 at baseline to 26.08 ± 27.99 after application. The questionnaire revealed that >80% patients were satisfied and requested the application of the desensitizing agent for future ultrasonic scaling sessions. CONCLUSION: This study shows that the application of the oxalic acid agent considerably reduces pain associated with dentin hypersensitivity experienced during ultrasonic scaling. This pain control treatment may improve patient participation and treatment efficiency.

Thrombospondin-1 production is enhanced by Porphyromonas gingivalis lipopolysaccharide in THP-1 cells.

Periodontitis is a chronic inflammatory disease caused by gram-negative anaerobic bacteria. Monocytes and macrophages stimulated by periodontopathic bacteria induce inflammatory mediators that cause tooth-supporting structure destruction and alveolar bone resorption. In this study, using a DNA microarray, we identified the enhanced gene expression of thrombospondin-1 (TSP-1) in human monocytic cells stimulated by Porphyromonas gingivalis lipopolysaccharide (LPS). TSP-1 is a multifunctional extracellular matrix protein that is upregulated during the inflammatory process. Recent studies have suggested that TSP-1 is associated with rheumatoid arthritis, diabetes mellitus, and osteoclastogenesis. TSP-1 is secreted from neutrophils, monocytes, and macrophages, which mediate immune responses at inflammatory regions. However, TSP-1 expression in periodontitis and the mechanisms underlying TSP-1 expression in human monocytic cells remain unknown. Here using real-time RT-PCR, we demonstrated that TSP-1 mRNA expression level was significantly upregulated in inflamed periodontitis gingival tissues and in P. gingivalis LPS-stimulated human monocytic cell line THP-1 cells. TSP-1 was expressed via Toll-like receptor (TLR) 2 and TLR4 pathways. In P. gingivalis LPS stimulation, TSP-1 expression was dependent upon TLR2 through the activation of NF-κB signaling. Furthermore, IL-17F synergistically enhanced P. gingivalis LPS-induced TSP-1 production. These results suggest that modulation of TSP-1 expression by P. gingivalis plays an important role in the progression and chronicity of periodontitis. It may also contribute a new target molecule for periodontal therapy.