PubMed Health⌕ Search

Biomedical subjects

A Rossbach

Publications and source records attributed to A Rossbach.

At least 19 recordsLinked to original sources
PubMed2003

Acidic solubility of luting cements.

OBJECTIVES: Chemical disintegration of luting cements can adversely affect their long term success. The aim of the present study was to assess the susceptibility of zinc phosphate cement, glass ionomer cement and resin cement to erosion at various pH values. METHODS: Zinc phosphate and glass ionomer cement samples were eroded in 0.3% citric acid adjusted to pH 3.0, 4.0, 5.0, 6.0 and 7.0 at a temperature of 35 degrees C. A control group was stored in saline. Profilometric readings were performed after 30 min and 1h erosion time. Resin cement samples were eroded at pH 3.0 with measurements after 30 min, 6h, 24h and 7 days. A saline control group was measured after 7 days. RESULTS: Erosion of zinc phosphate cement was significantly higher at all pH values than erosion of glass ionomer cement with erosion depth increasing with decreasing citric acid pH. No erosion was seen in the control groups. The resin cement did not show any change in surface profile after the 7 day erosion period compared to the control group. Comparison to dental tissues revealed that erosion of glass ionomer cement in vitro was slightly lower than erosion of enamel and dentine. In contrast, erosion of zinc phosphate cement was much higher.

Acids↗
PubMed1998

Computer-assisted milling of dental restorations using a new CAD/CAM data acquisition system.

BACKGROUND: Recent technologic innovations have created possibilities for restorative dentistry, such as computer-aided design and computer-aided manufacturing (CAD/CAM). PURPOSE: This article presents a new CAD/CAM process that has been developed for the fabrication of dental restorations. METHODS: This process uses an improved imaging technique, successfully applied in other industries. Imaging is accomplished with 2-dimensional line grids projected onto an object, which allows for a mathematical reproduction of prepared and unprepared tooth surfaces, including those that are outside the direct line of light. The relative position of the sensor to the surface of the object is controlled automatically. CONCLUSIONS: This system, which is undergoing clinical testing, allows the generation of various types of highly accurate dental restorations (inlays, onlays, crown, and fixed partial dentures) from a number of different materials. Acquired digitized data points are directly translated from the sensor to the electronic controls of the milling machine to provide various manufacturing possibilities, including copy milling and accurate reproduction of occlusal tooth surfaces in various materials.

Computer-Aided Design↗
PubMed1991

[Examinations of the temporal and spatial course of the reciprocal TMJ click].

A new computerized system for jaw movement registration allows a finer diagnosis of TMJ clicks. We recorded jaw movements in patients where we detected reciprocal clicks during clinical examination. We found two different types of derangements: an anterior displacement of the disk (as described by Farrar and a posterior displacement of the disk (similar to description of Klett).

Diagnosis, Computer-Assisted↗
PubMed1991

[The problem of the reproducibility of occlusal contacts].

To perform target orientated therapy simulators of condyle movements (CPS) have been introduced recently. It is believed to improve analysis of jaw by computer aided registration and evaluation systems (i.e. transformation of the true axis and jaw movements for use in articulators). Although the electronic evaluation systems helped to improve our understanding of the movements of the jaw, up to now the reproduction of physiological and pathological movements and their therapeutic changes have not been solved satisfactorily. The reason is sometimes miscorrection of system inherent projection errors. Additionally, numerical analysis and changes of the registered pathological movements are restricted to certain limits within the articulators for therapeutical purpose.

Dental Articulators↗
PubMed1990

[Three-dimensional dynamic imaging of TMJ movements using stereognathography].

Conventional imaging methods showing only one joint side are insufficient diagnostic tools for analyzing pathologic condyle paths. Although they demonstrate the effects of internal joint derangement, they fail to reveal the pathologic causes. Superior results are obtained by means of computer-assisted evaluation programs which allow simultaneous imaging of both joints in perspective.

Adult↗
PubMed1990

[Conservative treatment of perforated disks].

Stereognathographic recordings were taken of the mandibular movements of 11 patients who had undergone conservative treatment for unilateral disk perforation. The results showed a significant decrease in the condylar inclination angle of the affected joints. Based on these values the condylar inclinations were increased in a condyle positioning simulator (CPS). This allowed production of individually correct occlusal splints. In all cases studied this splinting therapy eliminated pain and crepitus.

Adult↗