The Effect of Locally Delivered Doxycycline in the Treatment of Chronic Periodontitis. A Clinical and Microbiological Cohort Study

Objectives: To evaluate the efficacy of locally delivered doxycycline as an adjunct to non-surgical treatment with the use of an ultrasonic device compared to scaling and root planing using hand instruments, by means of clinical and microbiological criteria.Material and Methods: Thirty three patients with chronic periodontitis participated in this cohort study and were divided into two groups. Patients in control group received scaling and root planing using hand instruments, whereas patients in control group received ultrasonic debridement and 8.8% doxycycline gel was applied after initial therapy and at 3 months at preselected sites. Clinical recordings concerning probing pocket depth, clinical attachment level, plaque index and gingival bleeding index were performed at baseline, 3 and 6 months after baseline. Subgingival samples were analysed using the “checkerboard” DNA-DNA hybridisation technique for Porphyromonas gingivalis, Tannerella forsythia and Treponema denticola.Results: Both treatments resulted in significant improvement in all clinical recordings. Six months after the treatment a statistically significant decrease was observed for Porphyromonas gingivalis in both of groups and Treponema denticola in the control group (P < 0.05). No inter-group differences were observed (P < 0.05).Conclusions: Both treatment modalities provided comparable clinical and microbiological results in the treatment of chronic periodontitis

Gains in cognition through combined cognitive and physical training: the role of training dosage and severity of neurocognitive disorder

Physical as well as cognitive training interventions improve specific cognitive functions but effects barely generalize on global cognition. Combined physical and cognitive training may overcome this shortcoming as physical training may facilitate the neuroplastic potential which, in turn, may be guided by cognitive training. This study aimed at investigating the benefits of combined training on global cognition while assessing the effect of training dosage and exploring the role of several potential effect modifiers. In this multi-center study, 322 older adults with or without neurocognitive disorders (NCDs) were allocated to a computerized, game-based, combined physical and cognitive training group (n = 237) or a passive control group (n = 85). Training group participants were allocated to different training dosages ranging from 24 to 110 potential sessions. In a pre-post-test design, global cognition was assessed by averaging standardized performance in working memory, episodic memory and executive function tests. The intervention group increased in global cognition compared to the control group, p = 0.002, Cohen's d = 0.31. Exploratory analysis revealed a trend for less benefits in participants with more severe NCD, p = 0.08 (cognitively healthy: d = 0.54; mild cognitive impairment: d = 0.19; dementia: d = 0.04). In participants without dementia, we found a dose-response effect of the potential number and of the completed number of training sessions on global cognition, p = 0.008 and p = 0.04, respectively. The results indicate that combined physical and cognitive training improves global cognition in a dose-responsive manner but these benefits may be less pronounced in older adults with more severe NCD. The long-lasting impact of combined training on the incidence and trajectory of NCDs in relation to its severity should be assessed in future long-term trials

Salicide-Like Process for the Formation of Gate and Source Contacts in 4H-SiC TSI-VJFETs

International audienceThe self-aligned approach allowed to fabricate 4H-SiC VJFETs with contact lithography with only 4 lithography steps. The main problem of this approch was the gate-source leakage current. In order to address this issue, a salicide process has been adopted resulting in a substantial reduction of the gate-source leakage current. The success of this approch paved the way for fabricating high power 4H-SiC devices with extremely low fabrication cost

A Continuous Semi-Empirical VJFET Capacitance Model from Sub to above Threshold Regime

International audienceThis paper presents and discusses the depletion mechanisms that dominate in a TSI-VJFET under different bias conditions as expressed by the gate-source (CGS) and gate-drain (CGD) capacitances. It is shown that at pinch off the dominant capacitance is the drift capacitance and that in conduction the drain source voltage plays a significant role in channel’s formation. Furthermore a semi empirical capacitance model is introduced. CGS and CGD are modeled below and above threshold voltage by considering parallel plate capacitors with different plate configuration in te two cases. Then, the derived expressions are unified using a transition function that preserves the continuity of the model. The model was adjusted and fitted adequately to measured CV data from fabricated TSI-VJFET

On the Optimum Determination and Use of SiC VJFET Threshold Voltage

International audienceThe threshold voltage of SiC JFETs has been determined from transfer characteristics by employing methods commonly used in the case of MOSFETs. The extracted values have been compared with the value determined from the fitting of experimental transfer characteristics with the Schockley model equation. Moreover, the variation of the extracted threshold voltage values with respect to channel width has been employed to determine the channel concentration without taking into account the Vbi value

Microbiome of peri-implantitis affected and healthy dental sites in patients with a history of chronic periodontitis.

To determine the composition of the microbiome of peri-implantitis sites and corresponding dental sites in subjects with a history of chronic periodontitis. Clinical and radiographic examination assessed the periodontal/peri-implant disease status. Plaque samples were collected from one diseased implant with peri-implantitis, functional for at least two years and healthy sites in ten non-smokers who had received periodontal treatment prior to implant placement. Following DNA extraction, the bacteria present in each sample were determined by high-throughput sequencing of V3-V4 region of the 16S rRNA gene using the Illumina MiSeq platform. OTUs were picked using QIIME. Differences between dental and implant sites were determined using linear discriminant analysis, effect size and diversity analyses were conducted using PAST v3.02. The microbiomes of healthy samples were more diverse than those found in disease, although disease was associated with a higher abundance of taxa relative to health. The genera Actinobacillus and Streptococcus were most closely associated with health, whereas Prevotella and Porphyromonas were most discriminative for disease. Synergistetes were highly associated with peri-implantitis. In patients with a history of periodontitis, putative periodontal pathogens prevailed in the microbiome of diseased implants. Diseased implants and corresponding healthy sites appear to have distinct microbiological ecosystems

Microbiome associated with peri-implantitis versus periodontal health in individuals with a history of periodontal disease

The microbiome of peri-implantitis sites and healthy dental sites was determined in subjects with a history of periodontitis. Ten systemically healthy non-smokers received periodontal treatment before implant placement. Plaque samples were collected from four sites of one implant with peri-implantitis (bone loss ≥2mm; PPD ≥6mm; BOP/suppuration; >1year loading) and from one dental site per quadrant with periodontal health (PPD ≤3mm, CAL <4mm, absence of BOP and bone loss). Following DNA extraction, the bacteria present in each sample were determined by high-throughput sequencing of the V3-V4 region of the 16S-rRNA gene using the Illumina-MiSeq platform. OTUs were picked using QIIME. Differences between dental and implant sites were determined using linear discriminant analysis, effect size and diversity analyses were conducted using PAST v3.02. The microbiomes of diseased samples were less diverse than those found in health, although disease was associated with a higher abundance of taxa relative to health. The genera Actinobacillus and Streptococcus were most closely associated with health, whereas Prevotella and Porphyromonas were most discriminative for disease. Other disease associated genera were Peptostreptococcus, Tannerella, Treponema, TG5 and Atopobium. Diseased peri-implant and healthy periodontal tissues in the same individual appear to harbour distinct microbiological ecosystems with putative periodontal pathogens predominating in the peri-implantitis-associated microbiome