Peter Portmann

Learn More
The aim of this study was to analyse the erosive effect of acidic lozenges and to compare it with that of orange juice, known to have the capacity to cause erosion. Two acidic, sugar-free lozenges and orange juice were tested in situ in nine patients. Changes in surface Knoop microhardness and change in the surface texture were assessed. The results(More)
AIM The aim of this in vivo study was to compare the radiographic quality of root fillings performed by the NIT-obturation method versus conventional mechanical obturation. METHODOLOGY Sixty-six patients needing root canal treatment participated in this study. The treatments were performed by three private practitioners. The root canals were instrumented(More)
Optimal cleansing of the root canal system is a prime prerequisite for long-term success in endodontics. Recently, a new method and device were presented providing "automatic" root canal cleansing without the need of endodontic instrumentation. Cleanliness results equivalent to or better than those with conventional methods were achieved in considerably(More)
The purpose of this study was to investigate the condensation pressure during amalgam placement in patients. Forty-four practitioners were asked to fill two class 2 cavities in the lower jaw on their patients in their own practice with the aid of a force-measuring plugger. This device, with semiconductor strain gauges, allowed the dentist to have an(More)
The aim of this in vitro study was to compare the sealing quality of three root canal filling materials after four years of ageing. Obturation with the non-instrumentation technique (NIT) was compared with cold lateral condensation of gutta-percha. Seventy-six canals were endodontically treated with traditional hand instrumentation and cold lateral(More)
In Switzerland, roundabouts enjoy a large and growing popularity. As a self-organizing system, they replace more and more the traditional traffic light systems. This article focuses on the modeling and simulation of a double tracked roundabout near Lucerne (Switzerland). The simulation results were used for decision purposes; in order to find out whether a(More)
A new machine that allows cleaning root canals without conventional instruments has been introduced. Because this noninstrumented technique does not enlarge the root canal system, a new device had to be developed to fill the root canal system. The new machine was able to produce a vacuum that allowed proper drying and filling of a root canal system. This(More)
Simulated segregating barley populations were screened for resistance to scald (Rhynchosporium secalis) in the field at commercial seeding rates. A reduction in infection on the susceptible component occurred with increasing proportions of resistant genotypes. Similar trends were seen in space planted experiments but the use of susceptible buffer rows(More)
A 0–4 scoring system to quantify scald (Rhynchosporium secalis) infection is suggested. Scores 1, 2, 3 and 4 allocated to represent 1/4, 1/2, 3/4 and 4/4 of the crop canopy scalded are easy to comprehend and intermediate scores e.g. 0.5, 1.5, 2.5 and 3.5 give it the breadth of a quantitative scale. Scores on a large number of lines showed a high degree of(More)