Bactericidal Efficacy of Cold Plasma at Different Depths of Infected Root Canals In Vitro

Objectives: Cold plasma (CP) has been shown to be effective even against multiresistant microorganisms. As previous investigations on the effect of CP in root canals showed promising results, the aim of the present study was to analyze the bactericidal efficacy of CP in different depths of infected dentin. Methods: 32 standardized root canals of human mandibular premolars were infected with Enterococcus faecalis and incubated for one week. Specimens were randomly selected for one of four disinfection methods: control (5mL NaCl), 5mL chlorhexidine (CHX), CP alone (CP), and a combination of 5mL CHX and cold plasma (CHX+CP). CHX was ultrasonically activated for 30s, while cold plasma was used for 60s in the root canals. Dentin samples at depths of 300, 500 and 800 µm were obtained and diluted serially. Colony forming units (CFUs) were counted on agar plates after 24h of incubation. Results: The highest overall logarithmic reduction factors (RF) were obtained from CHX+CP (log RF 3.56 p<0.01; Mann-Whitney U test), followed by CP (log RF 3.27 p<0.01) and CHX alone (log RF 2.65 p<0.01) related to the control. All disinfection methods showed significantly lower CFU counts compared to the control group in 300 µm and 800 µm (both p<0.01, Kruskal-Wallis test). Discussion: The adjuvant use of CP might be beneficial in highly infected root canals to improved disinfection. However, the disinfection effect against Enterococcus faecalis of CP is comparable to ultrasonically activated CHX

Disease Progression and Age as Factors Underlying Multimorbidity in Patients with COPD:Results from COSYCONET

Background: Multimorbidity plays an important role in chronic obstructive pulmonary disease (COPD) but is also a feature of ageing. We estimated to what extent increases in the prevalence of multimorbidity over time are attributable to COPD progression compared to increasing patient age. Methods: Patients with COPD from the long-term COSYCONET (COPD and Systemic Consequences - Comorbidities Network) cohort with four follow-up visits were included in this analysis. At each visit, symptoms, exacerbation history, quality of life and lung function were assessed, along with the comorbidities heart failure (HF), coronary artery disease (CAD), peripheral arterial disease (PAD), hypertension, sleep apnea, diabetes mellitus, hyperlipidemia, hyperuricemia and osteoporosis. Using longitudinal logistic regression analysis, we determined what proportion of the increase in the prevalence of comorbidities could be attributed to patients' age or to the progression of COPD over visits. Results: Of 2030 patients at baseline, 878 completed four follow-up visits (up to 4.5 years). CAD prevalence increased over time, with similar effects attributable to the 4.5-year follow-up, used as indicator of COPD progression, and to a 5-year increase in patients' age. The prevalence of HF, diabetes, hyperlipidemia, hyperuricemia, osteoporosis and sleep apnea showed stronger contributions of COPD progression than of age; in contrast, age dominated for hypertension and PAD. There were different relationships to patients' characteristics including BMI and sex. The results were not critically dependent on the duration of COPD prior to enrolment, or the inclusion of patients with all four follow-up visits vs those attending only at least one of them. Conclusion: Analyzing the increasing prevalence of multimorbidity in COPD over time, we separated age-independent contributions, probably reflecting intrinsic COPD-related disease progression, from age-dependent contributions. This distinction might be useful for the individual assessment of disease progression in COPD

Reduced decline of lung diffusing capacity in COPD patients with diabetes and metformin treatment

We studied whether in patients with COPD the use of metformin for diabetes treatment was linked to a pattern of lung function decline consistent with the hypothesis of anti-aging effects of metformin. Patients of GOLD grades 1-4 of the COSYCONET cohort with follow-up data of up to 4.5 y were included. The annual decline in lung function (FEV1, FVC) and CO diffusing capacity (KCO, TLCO) in %predicted at baseline was evaluated for associations with age, sex, BMI, pack-years, smoking status, baseline lung function, exacerbation risk, respiratory symptoms, cardiac disease, as well as metformin-containing therapy compared to patients without diabetes and metformin. Among 2741 patients, 1541 (mean age 64.4 y, 601 female) fulfilled the inclusion criteria. In the group with metformin treatment vs. non-diabetes the mean annual decline in KCO and TLCO was significantly lower (0.2 vs 2.3, 0.8 vs. 2.8%predicted, respectively;p < 0.05 each), but not the decline of FEV1 and FVC. These results were confirmed using multiple regression and propensity score analyses. Our findings demonstrate an association between the annual decline of lung diffusing capacity and the intake of metformin in patients with COPD consistent with the hypothesis of anti-aging effects of metformin as reflected in a surrogate marker of emphysema

Bactericidal Efficacy of Cold Plasma at Different Depths of Infected Root Canals In Vitro

OBJECTIVES: Cold plasma (CP) has been shown to be effective even against multiresistant microorganisms. As previous investigations on the effect of CP in root canals showed promising results, the aim of the present study was to analyze the bactericidal efficacy of CP in different depths of infected dentin. METHODS: 32 standardized root canals of human mandibular premolars were infected with Enterococcus faecalis and incubated for one week. Specimens were randomly selected for one of four disinfection methods: control (5mL NaCl), 5mL chlorhexidine (CHX), CP alone (CP), and a combination of 5mL CHX and cold plasma (CHX+CP). CHX was ultrasonically activated for 30s, while cold plasma was used for 60s in the root canals. Dentin samples at depths of 300, 500 and 800 µm were obtained and diluted serially. Colony forming units (CFUs) were counted on agar plates after 24h of incubation. RESULTS: The highest overall logarithmic reduction factors (RF) were obtained from CHX+CP (log RF 3.56 p<0.01; Mann-Whitney U test), followed by CP (log RF 3.27 p<0.01) and CHX alone (log RF 2.65 p<0.01) related to the control. All disinfection methods showed significantly lower CFU counts compared to the control group in 300 µm and 800 µm (both p<0.01, Kruskal-Wallis test). DISCUSSION: The adjuvant use of CP might be beneficial in highly infected root canals to improved disinfection. However, the disinfection effect against Enterococcus faecalis of CP is comparable to ultrasonically activated CHX

Abstracts of the 6th FECS Conference 1998 Lectures

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