The prevalence of approximal caries in patients after fixed orthodontic treatment and in untreated subjects: A retrospective, cross-sectional study on bitewing radiographs

Objective: The aim of this retrospective, cross-sectional study was to investigate the prevalence of approximal carious lesions in patients after fixed multibracket therapy and in subjects without orthodontics on bitewing radiographs. Material and methods: Bitewing radiographs of 104orthodontically treated patients with fixed multibracket appliances were compared to those of 111untreated subjects. The individuals in both groups were between 15 and 16.25years of age when radiographs were taken. The test group with orthodontics was recruited from the archive of the Department of Orthodontics at the University of Zürich. The untreated control group was selected randomly from 16communities in the Canton of Zürich. The approximal surfaces of the permanent premolars and molars of all subjects were assessed by two calibrated investigators. Results: The average number of enamel lesions in the test group after fixed orthodontic treatment was lower than in the control group (0.57 vs. 1.85, p < 0.001). The same was found for dentin lesions (0.06 vs. 0.49, p < 0.001). The distribution of lesions was similar in both groups. Conclusion: Fewer approximal carious lesions were detected in the test group after fixed multibracket appliances than in the age-matched control group without orthodontic treatmen

Electrical tomography and TDEM prospection in the Chianciano thermal basin (Siena, Italy)

Chianciano thermal basin in Tuscany belongs to a great structure that extends, from San Casciano Bagni to Rapolano, orientated SSE-NNW. Several springs are located in this thermal field: Acqua Santa, Macerina, Casuccini and Sillene well. They are located close to the contact between the lower complex of the «Tuscan series» (Triassic limestones and dolomites) and Pliocene formations (sands and clayey sands, clays and silty clays). According to the groundwater flow scheme, the former formations represent the geothermal reservoir and, where they outcrop, the recharge areas. Thermalized fluids rise through direct faults, having an apennine orientation. In order to locate a new production well, electrical tomography and TDEM prospection were performed. Geophysical interpretation led to the construction of 1D imaged and 2D sections showing the main tectonic features. The different electrical behaviour of the hydrogeological units disclosed a fault located near the old Sillene well; this tectonic feature caused the uplifting of Triassic formations towards the north-east. A new production well was located close to the fault in the uplifted sector with excellent results as it captured the thermal aquifer at a depth of 30 m with a discharge up to 70 l/s

Direct visualization of magnetic vortex pinning in superconductors

We study the vortex structure in a Pb film deposited on top of a periodic array of ferromagnetic square microrings by combining two high resolution imaging techniques: Bitter decoration and scanning Hall probe microscopy (SHPM). The periodicity and strength of the magnetic pinning potential generated by the square microrings are controlled by the magnetic history of the template. When the square rings are in the magnetized dipolar state, known as the onion state, the strong stray field generated at the domain walls prevents the decoration of vortices. SHPM images show that the stray field generated by the dipoles is much stronger than the vortex field in agreement with the results of simulations. Real space vortex imaging has revealed that, in the onion state, the corners of the square rings act as effective pinning centers for vortices.Comment: To be published in Phys. Rev.

Weiterer Kariesrückgang bei Schweizer Rekruten von 1996 bis 2006

Rekruten der Rekrutenschule Thun (N = 606) wurden im Jahr 2006 mit einer standardisierten Methode zahnmedizinisch untersucht. Die Resultate wurden mit denjenigen aus früheren Erhebungen (1985 und 1996) verglichen. Der DM6FT-Wert betrug im Jahr 2006 im Durchschnitt 3,11; im Jahr 1996 lag er noch deutlich höher (4,95). Dies entspricht einem Kariesrückgang von 37%. Der beobachtete Kariesrückgang konnte nur zum Teil erklärt werden. Rekruten, die rauchten, zeigten einen erhöhten Kariesbefall. Rekruten aus der Deutschschweiz, die in Kindergarten und Primarschule von Schulzahnpflege- Instruktorinnen betreut worden waren, unterschieden sich im Kariesbefall nicht von den Rekruten aus der Romandie

Further caries decline in Swiss recruits from 1996 to 2006

Swiss army recruits (N = 606) from the army base at Thun were dentally examined with a standardized method in the year 2006. The results were compared with those of previous surveys (1985 and 1996). The mean DM6FT-value in the year 2006 was 3.11, whereas in 1996 it had been clearly higher (4.95). This corresponds to a caries decline of 37%. The observed caries decline can only partly be explained. Recruits, who were smokers, showed an increased caries experience. Recruits of the German-speaking part of Switzerland who had profited from oral health lessons by oral health instructors in Kindergarten and primary schools did not differ in caries experience from recruits of the French-speaking part of Switzerland

Collagen Fiber Arrangement in Temporo-Mandibular Joint (TMJ) Disks from Human Subjects with Functional Diseases. Scanning Electron Microscopy Investigations

Twelve articular disks from patients with temporo-mandibular joint (TMJ) arthropathy were studied and compared with two normal disks. Scanning electron microscopy (SEM) examination of the surfaces and of longitudinal and cross-sections of the disks allowed the observation of the arrangement of the collagen fiber component in different parts of the disk. The superficial part of the articular disks appears to be formed by rather compact fibers. The internal portion is usually formed by bundles of collagen fibers in sheets, alternating with isolated fibers arranged in a parallel or irregular way. In some samples, blood vessels were observed. Our investigations suggested that the appearance of vascularization is the first remarkable histological change that can be observed in functionally abnormal articular disks