Orthodontic therapy with fixed appliances bears a high risk of plaque accumulation, resulting in demineralization and new carious lesions. Rather than treat incipient lesions in orthodontic patients, most general dental practitioners decide to await future developments. A new concept for comprehensive restorative and endodontic treatment is presented, and its orthodontic implications are discussed.
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August 1992
Discoloring and layers on bands and restorations during fixed orthodontic therapy are well known clinical phenomenon. Because of the complexity of etiological factors an in-vitro model was used in this study. Aim of the study was to examine the amounts and sort of metals which are dissolved.
View Article and Find Full Text PDFA number of clinical and experimental studies were performed to assess the quality of the enamel-adhesive-bracket bond. The aim was to present a combined method that enables the investigator both to examine the surface of metal brackets quantitative-morphometrically and to detect the presence of enamel particles. To this end, 38 metal brackets were examined in the scanning electron microscope.
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April 1992
The aim of the present in-vitro study was to evaluate the changes in pulp temperature associated with thermal debonding of ceramic brackets using the Ceramic Debonding Unit (Dentaurum). In addition, several forms of false usage were simulated. Instead of thermoelements, the non-contact infrared thermography device SST/THETA 1000 (Heimann) was employed for the dynamic measurement of pulp temperature.
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February 1992
Thanks to their capability for post-processing of image data, the digital radiological techniques introduced from 1970 onwards permit dose reduction with no loss of clinical information. The aim of this study was to establish the extent of possible dose reduction in orthodontic lateral cephalography. For this purpose, lateral cephalograms of a head phantom taken with varying radiation doses (5 to 150 mAs, constant 70 kV) were evaluated.
View Article and Find Full Text PDFInt J Adult Orthodon Orthognath Surg
January 1993
Questionnaires and psychological tests were used to assess the psychosocial impact of mandibular prognathism. Patients with mandibular prognathism were asked to assess the impediments caused by their dentofacial deformity. In addition, they were asked to rate their appearance and to report the effect that it had on their social contacts.
View Article and Find Full Text PDFDtsch Zahn Mund Kieferheilkd Zentralbl
January 1993
The purpose of this study was the evaluation of digital luminescence radiography (PCR; Philips Computed Radiography) used in routine radiological analysis of the facial skull. Besides the standard radiographs additional PCR shots were taken in 16 cases. The subjective evaluation was carried out by three different people using clinical criteria.
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December 1991
Although there have been many advances in the field of acid etching, major problems still present. For the most part, these are the unpredictability of the effects of etching, the lack of control of the depth of etching over the long term, and the development of enamel fractures occurring on debonding. The aim of this study was to investigate the morphological effects of enamel conditioning using a pulsed krypton fluoride excimer laser (wavelength 248 nm).
View Article and Find Full Text PDFThe purpose of this study was to present possible advantages of digital luminescence radiography for cephalometry. Conventional and digitalized lateral headfilms were compared and evaluated. The first impression of an improved simultaneous presentation of bony structures and soft tissue profile in digital x-rays was statistically verified.
View Article and Find Full Text PDFIf (secondary) caries or amalgam fractures occur during fixed orthodontic treatment, the general dentist usually faces difficulties. Often temporary fillings are inadequate. Due to marginal leakage or break down they may jeopardize an orthodontic result.
View Article and Find Full Text PDFBy introduction of rare earth film-screen combinations instead of classical screens dose reduction has already been possible. By this study the extent of dose reduction without loss of clinical information was to be examined by comparing conventional radiographic rare earth film-screen combinations to digital radiography. Statistical analysis proves for conventional lateral cephalograms that soft tissue reference points can better be localized if small radiation doses are used.
View Article and Find Full Text PDFThermal debonding of ceramic brackets is now used for some time. In this context the possibility of a thermal damage of the pulp is one of the main questions. With the aid of a touchless infrared thermography device (SST/Theta 1,000; Heimann, FRG-Wiesbaden) the consequences of thermal debonding with the "Ceramic Debonding Unit" (Dentaurum, Pforzheim) have been studied.
View Article and Find Full Text PDFBrook trout (Salvelinus fontinalis) were immunized with bacterins containing either Serotype 1 or 2 isolates of Yersinia ruckeri to determine the relative degree of cross-protection afforded when the fish were challenged with the homologous or heterologous serotype. While fish immunized with pH-lysed bacterins produced highly specific agglutinins that did not cross-react with antigens derived from a heterologous serotype of Y. ruckeri all fish were protected against experimental challenge, regardless of which serotype was used for bacterin production and experimental challenge.
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