International Journal of Computerized Dentistry, 02/2008

On the basis of well-founded clinical evaluations and taking into account special methodological recommendations, surface electromyography (EMG) enables the acquisition of valid and reliable quantitative data on the functional condition of the masticatory muscles as a "neuromuscular functional analysis". On the basis of a current review of the literature, surface EMG appears to be able to deliver additional diagnostic and therapy-relevant information. Meaningful EMG data can be gained regarding resting activity, maximum muscle activation, frequency spectrum under various loading conditions, as well as bilateral symmetry of the contraction behavior of the jaw muscles. With these parameters - completed by kinematic information on movements of the mandible - it appears to be possible under clinical conditions to assess a) the neuromuscular chewing performance after prosthetic reconstructions, b) to record the influence of pain on the neuromuscular system, and c) to document the individual efffect of therapeutic interventions on temporomandibular disorders. Keywords: electromyography, chewing, masticatory muscles, fatigue, orofacial pain, pain adaptation model, maximum voluntary contraction, symmetry, reliability, resting activity

This article discusses basic concepts of noise suppression for digital radiographs, and shows how false application of algorithms available can lead to a loss of information. Noise suppression realized with low pass convolution filters are designed to decrease strong grey level changes of neighboring pixels. Sixty-two extracted fully intact premolars were selected and treated using the crown-down technique to prepare them for experimental fractures. A total of 358 radiographs were taken, of which 312 images were selected with clearly visible root fractures. The selected radiographs were stored as uncompressed images and manipulated with 8 different convolution filters. A total of 2496 raw and filtered images were inspected for visible root fractures. Only the arithmetic mean filter with 5 x 5 kernel size led to a deletion of the visible fracture line in 33.3% of the inspected cases. The other filters proved to be useful for noise reduction without loss of any necessary diagnostic information. None of the filters improved the diagnostic outcome in the 46 remaining radiographs which did not show clearly visible root fractures before application of the filters. Keywords: digital noise filters, root fractures, direct digital radiographs

The provision of patients with removable partial dentures on all-ceramic primary crowns with electroplated gold secondary parts is described as an alternative worthy of consideration in dental journals, lectures and in further training courses. The mode of operation is based on a precise, frictionless, passive fit between female and male components. To guarantee this even over large spans, intraoral joining of the individual components is necessary. However, this requires a different sequence of the treatment steps. The different procedures (conventional, procedure by Weigl, modified concept) are described in the following article. Clinical considerations, design principles, and special characteristics involved in producing the partial denture are explained. Keywords: all-ceramic primary parts, sequence of procedures, intraoral cementing, telescopic prosthetics, double crowns

This paper describes a special case in which Cerec 3 chair-side could successfully replace a congenitally missing lat-eral incisor using a cantilever approach. The patient wasin her mid-thirties and well motivated towards the fullceramic treatment. The waxed-up model along with thesoftware yielded a creative Cerec-produced cantileverbridge across tooth 12 and attached to tooth 13. Sur-prisingly, the veneer on the canine could support a can-tilever (on the lateral incisor) with very good performanceto date (over 1 year). Keywords: CAD/CAM, Cerec, cantilever, veneers, anterior teeth, correlation