Search

This work constitutes a new trial to enhance the properties of palladium supported on alumina modified with zirconium used as catalysts for methane combustion. The effect of the support drying mode is studied. For this aim, Al2O3-ZrO2 binary oxides with zirconium loading of 2 and 5% in weight were prepared using sol–gel process then dried under ordinary or supercritical conditions. Palladium with a loading of 0.5% was deposited on the support by wet impregnation. Several techniques have been used to investigate differences between the two types of the derived catalysts. [ABSTRACT FROM AUTHOR]

A series of Pd/Al2O3–ZrO2 materials have been prepared via sol gel method as an attractive route to obtain more homogeneous binary oxides Al2O3–ZrO2. A Zr loading between 2 and 15 wt% was used to investigate the Zr promotion of Pd/Al2O3 materials. The prepared catalysts were calcined at two different temperatures. Very interesting results have been obtained at low zirconium content. A small amount of Zr is seen to be sufficient to stabilize the activity and to obtain good catalytic performances with developed textural properties compared to conventional catalysts used to oxidize methane. The increase of the zirconium loading is seen to decrease the catalytic activity may be due to the development of tetragonal zirconia phase detected by XRD. Similar effect has been observed after heating catalysts at high temperatures. A loss in BET surface area and in metal dispersion has been also observed for zirconium rich catalysts. A contradictory effect on textural and structural properties is seen after their calcination at 700 °C. [ABSTRACT FROM AUTHOR]

Background and Objectives : Periodontal therapy aims to arrest the progression of periodontal diseases and possibly to regenerate the periodontal apparatus. To shift healing from repair to regeneration, the blood clot that fills the periodontal defect and remains in contact with structures such as tooth root, mucosa and bone needs to be stable, which is a reason why the treatment of non-containing periodontal bone defects, in which the clot may undergo displacement, is challenging. The gingival soft tissue, properly sutured, may act as a wall for blood clot stabilization. Knowledge on the response of the blood clot to stress and how it might vary according to the characteristics of the tissues it gets in contact with might be deepened. The aim of this study was to investigate in vitro, by means of a micro-loading device, the response of the complex formed by a blood clot and diverse tissues, simulating those involved in periodontal regeneration, to a displacing tensile test. Materials and Methods : Experimental samples made of two layers of either hard dental tissues, cancellous bone or oral mucosa, between which fresh blood was interposed, underwent a debonding experiment by means of a micro-loading device that measured their response to uniaxial tensile stress. Results : The peak of tensile stress and the overall work needed for the complete rupture of the clot's fibrin filaments were significantly higher for hard dental tissues than for other tissues. However, mucosa sustained the highest maximal strain in terms of relative displacement between the plates of the micro-loading device to accomplish the complete rupture of the fibrin filaments compared to the other tissues, suggesting that the mucosa might act as a stable interface with the clot and be able to sustain tensile stresses. Conclusions : This in vitro study seems to support the use of mucosa to act as a wall for regenerative procedures of suprabony periodontal defects given its capability to form a stable interface with the clot.

Objective: An association between periodontitis and arterial hypertension has been suggested recently. This study aimed at investigating the hypothesis that periodontal health is linked to incident arterial hypertension., Methods: We analyzed data from the French population-based e-cohort NutriNet-Santé, selecting participants who had completed two oral health questionnaires in 2011-2012. Pregnant women, participants with diabetes, cancer, arterial hypertension and cardiovascular diseases at inclusion were excluded. Incident cases of arterial hypertension were self-reported and/or based on the use of antihypertensive therapy. Periodontal health was evaluated by estimating the modified and validated PEriodontal Screening Score (mPESS), with mPESS at least 5 corresponding to a high probability of severe periodontitis. Descriptive statistics and Cox proportional hazards regression models, taking into account sociodemographic and lifestyle confounders, were used., Results: The study population consisted of 32 285 participants (mean age: 45.79 ± 13.87 years); 78.5% were women. Two thousand one hundred and sixteen incident cases of arterial hypertension were identified during a median follow-up of 8 years (April 2012--December 2019). In the fully adjusted model, an mPESS at least 5 [hazard ratio: 1.84; 95% confidence interval (CI): 1.66-2.03] and the presence of nonreplaced missing teeth (hazard ratio: 1.13; 95% CI: 1.03-1.23) were significantly associated with a greater risk of incident arterial hypertension, whereas a regular annual visit to the dentist was associated with a lower risk (hazard ratio: 0.88; 95% CI: 0.80-0.97)., Conclusion: Self-reported assessed periodontitis was associated with incident arterial hypertension over an 8-year period. The present results highlight the importance of considering periodontal health when assessing an individual's risk of arterial hypertension., Trial Registration: # NCT03335644., (Copyright © 2021 The Author(s). Published by Wolters Kluwer Health, Inc.)

Background: Recent evidence suggests that dietary habits influence the development and severity of periodontitis. The present cross-sectional study evaluated the association between different types and quantity of alcoholic beverage consumption (alone and interacting with smoking) and the probability to suffer from severe periodontitis in the French e-cohort NutriNet-Santé., Methods: The study population consisted of 35,390 adults (mean age: 49.04 ± 13.94 years), who filled oral health questionnaires and completed at least three non-consecutive 24-hour dietary records. Data on type and frequency of alcoholic beverage consumption were obtained from a semi-quantitative self-reported alcohol frequency questionnaire; the daily quantity (g/day) was estimated from the 24-hour dietary records. The probability of severe periodontitis (main dependent variable) was assessed by calculating the modified periodontal screening score (mPESS) from selected questions., Results: A total of 7263 individuals (20.5%) presented a high probability of suffering from severe periodontitis (high-mPESS). After adjusting for confounding factors, the frequency of alcoholic beverage consumption was significantly higher among high-mPESS group than their low-mPESS counterparts, especially for hard liquor/spirits (1.9 ± 1.4 days/week for high-PESS versus 1.6 ± 1.1 days/week the low-PESS [P < 0.0001]). The mean daily quantity of ethanol was also higher in high-mPESS versus low-mPESS individuals (11.2 ± 15.6 versus 7.9 ± 12.3 g/day; P = 0.011). A stronger association with self-report severe periodontitis was noted when alcohol consumption exceeding > 20 g/day for women and > 30 g/day for men was combined with smoking habit (OR = 7.30 [95% CI: 6.1-8.73])., Conclusion: The present results support an association between alcoholic beverage consumption and self-report severe periodontitis, particularly when it is associated with current smoking., (© 2020 American Academy of Periodontology.)

Aim: The aim of the present prospective study was to evaluate the impact of a computer-controlled anesthesia on patients' comfort and to investigate, through the willingness-to-pay (WTP) index, and patients' acceptance of this new technology., Methods: Fifty patients undergoing a class I or II restorative procedure were enrolled. A computer-controlled device for anesthetic delivery was utilized, and a questionnaire on the level of discomfort and WTP was given to all patients., Results: A total of 86% of participants declared less discomfort than that perceived during their last traditional procedure for pain control; 58% of patients were willing to pay an additional fee for a modern anesthesia technique, with a median WTP value of 20$., Conclusions: Computer-controlled systems for local anesthesia represent a relevant tool for reducing patients' discomfort during dental treatment. The WTP index helps to quantify its relevance., (© 2017 John Wiley & Sons Australia, Ltd.)

Aim: There have been no modifications made to the original double papillae flap surgical technique introduced by Cohen and Ross in 1968. The aim of the present case series is to evaluate the effectiveness of a modified surgical approach to the double papillae flap design in the treatment of isolated gingival recession., Materials and Methods: A total of 12 healthy, young patients (age range 20 to 28 years) with isolated gingival recession were enrolled in this study. The gingival recession had the following characteristics: isolated defect, Miller Class I or II defect, visible cementoenamel junction (CEJ), and well represented interdental papillae. The following clinical measurements were taken before the surgery and at the 1-year follow-up examination: probing depth (PD) at the treated tooth, clinical attachment level (CAL), amount of keratinized tissue (KT) at the treated site, and recession depth (RD). All measurements were taken at baseline and after 12 months by means of a manual probe and were rounded up to the nearest millimeter., Results: At the 1-year follow-up examination, the same clinical parameters taken at baseline were rerecorded. No statistical differences were noted for the PD (P=0.54). The mean increase for the CAL was statistically significant (P=0.04). Furthermore, the mean amount of KT increased by 2.5±0.4 mm (P<0.001). Finally, the mean RD decreased to 0.5±0.6 mm, corresponding to a root coverage of 3.8±0.8 mm (P<0.001). In terms of mean root coverage (MRC), 88.4% of exposed root surface was covered with soft tissue, and 9 of the 12 treated teeth (75%) showed complete coverage of the root surface., Conclusion: The results of the present case series show that the modified double papillae flap technique is effective in obtaining root coverage of isolated gingival recession defects. These rootcoverage outcomes were associated with clinically and statistically highly significant clinical attachment gain, with no noticeable change in either the PD values or the height of KT on the buccal aspect of the treated teeth.