Immediate and early non-occlusal loading of Straumann implants with a chemically modified surface (SLActive) in the posterior mandible and maxilla: interim results from a prospective multicenter randomized-controlled study

OBJECTIVE: Immediate and early loading of dental implants can simplify treatment and increase overall patient satisfaction. The purpose of this 3-year prospective randomized-controlled multicenter study was to assess the differences in survival rates and bone level changes between immediately and early-loaded implants with a new chemically modified surface (SLActive). This investigation shows interim results obtained after 5 months. MATERIAL AND METHODS: Patients > or =18 years of age missing at least one tooth in the posterior maxilla or mandible were enrolled in the study. Following implant placement, patients received a temporary restoration either on the day of surgery (immediate loading) or 28-34 days after surgery (early loading); restorations consisted of single crowns or two to four unit fixed dental prostheses. Permanent restorations were placed 20-23 weeks following surgery. The primary efficacy variable was change in bone level (assessed by standardized radiographs) from baseline to 5 months; secondary variables included implant survival and success rates. RESULTS: A total of 266 patients were enrolled (118 males and 148 females), and a total of 383 implants were placed (197 and 186 in the immediate and early loading groups, respectively). Mean patient age was 46.3+/-12.8 years. After 5 months, implant survival rates were 98% in the immediate group and 97% in the early group. Mean bone level change from baseline was 0.81+/-0.89 mm in the immediate group and 0.56+/-0.73 mm in the early group (P<0.05). Statistical analysis revealed a significant center effect (P<0.0001) and a significant treatment x center interaction (P=0.008). CONCLUSIONS: The results suggested that Straumann implants with an SLActive can be used predictably in time-critical (early or immediate) loading treatment protocols when appropriate patient selection criteria are observed. The mean bone level changes observed from baseline to 5 months (0.56 and 0.81 mm) corresponded to physiological observations from other studies, i.e., were not clinically significant. The presence of a significant center effect and treatment x center interaction indicated that the differences in bone level changes between the two groups were center dependent.

Significantly shorter telomeres in T-cells of patients with ZAP-70+/CD38+ chronic lymphocytic leukaemia

In contrast to other B-cell neoplasias, chronic lymphocytic leukaemia (CLL) is characterized by increased non-leukaemic T-cells. In order to assess their replicative history, telomere length was analyzed in subsets of leucocytes from CLL patients. Naive and memory T-cells from ZAP-70(+)/CD38(+) patients exhibited significantly shorter average telomere lengths than ZAP-70(-)/CD38(-) patients. Compared to the age-related percentiles of telomere length values from healthy individuals practically all values of the naive and memory T-cells from the ZAP-70(+)/CD38(+) CLL patients fell below the 50th percentile. This indicated an extensive expansion and a role for T-cells in ZAP-70(+)/CD38(+) CLL patients.

Vibro-acoustical analysis and design of a multiple-layer constrained viscoelastic damping structure

The goal of this research is to provide a framework for vibro-acoustical analysis and design of a multiple-layer constrained damping structure. The existing research on damping and viscoelastic damping mechanism is limited to the following four mainstream approaches: modeling techniques of damping treatments/materials; control through the electrical-mechanical effect using the piezoelectric layer; optimization by adjusting the parameters of the structure to meet the design requirements; and identification of the damping material’s properties through the response of the structure. This research proposes a systematic design methodology for the multiple-layer constrained damping beam giving consideration to vibro-acoustics. A modeling technique to study the vibro-acoustics of multiple-layered viscoelastic laminated beams using the Biot damping model is presented using a hybrid numerical model. The boundary element method (BEM) is used to model the acoustical cavity whereas the Finite Element Method (FEM) is the basis for vibration analysis of the multiple-layered beam structure. Through the proposed procedure, the analysis can easily be extended to other complex geometry with arbitrary boundary conditions. The nonlinear behavior of viscoelastic damping materials is represented by the Biot damping model taking into account the effects of frequency, temperature and different damping materials for individual layers. A curve-fitting procedure used to obtain the Biot constants for different damping materials for each temperature is explained. The results from structural vibration analysis for selected beams agree with published closed-form results and results for the radiated noise for a sample beam structure obtained using a commercial BEM software is compared with the acoustical results of the same beam with using the Biot damping model. The extension of the Biot damping model is demonstrated to study MDOF (Multiple Degrees of Freedom) dynamics equations of a discrete system in order to introduce different types of viscoelastic damping materials. The mechanical properties of viscoelastic damping materials such as shear modulus and loss factor change with respect to different ambient temperatures and frequencies. The application of multiple-layer treatment increases the damping characteristic of the structure significantly and thus helps to attenuate the vibration and noise for a broad range of frequency and temperature. The main contributions of this dissertation include the following three major tasks: 1) Study of the viscoelastic damping mechanism and the dynamics equation of a multilayer damped system incorporating the Biot damping model. 2) Building the Finite Element Method (FEM) model of the multiple-layer constrained viscoelastic damping beam and conducting the vibration analysis. 3) Extending the vibration problem to the Boundary Element Method (BEM) based acoustical problem and comparing the results with commercial simulation software.

Intrarenal resistance index for the assessment of early renal function impairment in patients with liver cirrhosis

BACKGROUND: Renovascular vasoconstriction in patients with hepatorenal syndrome can be quantified by the renal arterial resistance index (RI). We investigated the value of RI measurement in detection of renal function impairment in patients with different stages of chronic liver disease. METHODS: Subjects were divided into 4 groups containing 21 patients with liver cirrhosis and ascites, 25 patients with liver cirrhosis without ascites, 35 patients with fatty liver disease and 78 control subjects. All patients underwent abdominal ultrasound examination with renal RI measurement and correlation with laboratory results for renal function. RESULTS: RI was significantly higher in ascitic patients compared to non-ascitic patients (0.74 vs. 0.67, p<0.01) and in non-ascitic patients with liver cirrhosis than in control subjects (0.67 vs. 0.62, p<0.01). 48% (19/40) of patients with liver cirrhosis and normal serum creatinine concentration showed elevated RI levels. There were no significant differences in RI levels between patients with fatty liver disease and controls (0.63 vs. 0.62). CONCLUSIONS: Intrarenal RI measurement is a predictor of renal vasoconstriction and serves to detect early renal function impairment in cirrhotic patients. The diagnosis of elevated RI may be taken into account in the clinical management of these patients.

BNP-guided vs symptom-guided heart failure therapy: the Trial of Intensified vs Standard Medical Therapy in Elderly Patients With Congestive Heart Failure (TIME-CHF) randomized trial

CONTEXT: It is uncertain whether intensified heart failure therapy guided by N-terminal brain natriuretic peptide (BNP) is superior to symptom-guided therapy. OBJECTIVE: To compare 18-month outcomes of N-terminal BNP-guided vs symptom-guided heart failure therapy. DESIGN, SETTING, AND PATIENTS: Randomized controlled multicenter Trial of Intensified vs Standard Medical Therapy in Elderly Patients With Congestive Heart Failure (TIME-CHF) of 499 patients aged 60 years or older with systolic heart failure (ejection fraction < or = 45%), New York Heart Association (NYHA) class of II or greater, prior hospitalization for heart failure within 1 year, and N-terminal BNP level of 2 or more times the upper limit of normal. The study had an 18-month follow-up and it was conducted at 15 outpatient centers in Switzerland and Germany between January 2003 and June 2008. INTERVENTION: Uptitration of guideline-based treatments to reduce symptoms to NYHA class of II or less (symptom-guided therapy) and BNP level of 2 times or less the upper limit of normal and symptoms to NYHA class of II or less (BNP-guided therapy). MAIN OUTCOME MEASURES: Primary outcomes were 18-month survival free of all-cause hospitalizations and quality of life as assessed by structured validated questionnaires. RESULTS: Heart failure therapy guided by N-terminal BNP and symptom-guided therapy resulted in similar rates of survival free of all-cause hospitalizations (41% vs 40%, respectively; hazard ratio [HR], 0.91 [95% CI, 0.72-1.14]; P = .39). Patients' quality-of-life metrics improved over 18 months of follow-up but these improvements were similar in both the N-terminal BNP-guided and symptom-guided strategies. Compared with the symptom-guided group, survival free of hospitalization for heart failure, a secondary end point, was higher among those in the N-terminal BNP-guided group (72% vs 62%, respectively; HR, 0.68 [95% CI, 0.50-0.92]; P = .01). Heart failure therapy guided by N-terminal BNP improved outcomes in patients aged 60 to 75 years but not in those aged 75 years or older (P < .02 for interaction) CONCLUSION: Heart failure therapy guided by N-terminal BNP did not improve overall clinical outcomes or quality of life compared with symptom-guided treatment. TRIAL REGISTRATION: isrctn.org Identifier: ISRCTN43596477.

Clinical effects of interdental cleansing on supragingival biofilm formation and development of experimental gingivitis

PURPOSE: The aim of the present study was to test the effects of interdental cleansing with dental floss on supragingival biofilm removal in natural dentition during a 3-week period of experimental biofilm accumulation. MATERIALS AND METHODS: The present study was performed as a single-blind, parallel, randomised, controlled clinical trial using the experimental gingivitis model (Löe et al, 1965). Thirty-two students were recruited and assigned to one of the following experimental or control groups: Group A used a fluoride-containing dentifrice (NaF dentifrice) on a toothbrush for 60 s twice a day, Group B used an unwaxed dental floss twice a day, Group C used a waxed dental floss twice a day in every interproximal space and Group D rinsed twice a day for 60 s with drinking water (control). RESULTS: During 21 days of abolished oral hygiene, the groups developed various amounts of plaque and gingivitis. Neither of the cleansing protocols alone allowed the prevention of gingivitis development. Toothbrushing alone yielded better outcomes than did any of the flossing protocols. Interdental cleansing with a waxed floss had better biofilm removal effects than with unwaxed floss. CONCLUSIONS: Toothbrushing without interdental cleansing using dental floss and interdental cleansing alone cannot prevent the development of gingivitis.