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Biomedical subjects

H F Kappert

Publications and source records attributed to H F Kappert.

At least 37 records · Page 2Linked to original sources
PubMed1989

[Effects of the mode of ceramization on the compressive strength of Dicor crowns. A laboratory study].

The critical compressive strength of cast glass-ceramic samples with a standardised shape was evaluated as a function of the ceramization temperature. The maximum critical compressive stress was obtained under conditions prescribed by the manufacturer. After under- and overceramization by only 6 degrees C, as well as after repeated ceramization, the critical compressive strength was decreased significantly (p less than or equal to 0.05) by about 13-24%.

Ceramics↗
PubMed1989

[Frequency spectrum and integral value of electromyographic recordings of the masseter and temporal muscles in correlation with muscle length].

In 15 children and 15 adults the influence of muscle length on the EMG-recordings of the anterior temporal and superficial masseter muscles was investigated. Myoelectric activity was measured by surface electromyography during maximal clenching in habitual occlusion. The quantitative EMG analysis was performed by means of a computer program which allowed calculation of a) the integrated value and b) the mean frequency of the power spectrum (MPF) from the raw signal after Fourier transformation. Muscle length was determined with the aid of lateral cephalometric films. Using a correlation analysis this investigation revealed the following results: Under standardized functional conditions short muscles work with a higher activity and a higher MPF than long muscles. In children as well as in adults muscle activity and MPF show close negative correlations with the parameter "muscle length". These relations are directly proportional.

Adult↗
PubMed1989

[Testing metal/acrylic bonds for shear strength, axial tensile strength and maximum bending stress].

The effects of thermocycling and water penetration on the bond strength of resin-metal-systems and improvements using bonding agents have been tested by shear, bending and tensile tests. After 10,000 cycles within 10 days in different water-baths with 5-37-55 degrees C, there is a decrease in bond strength by 40 to 60%. The use of bonding agents increases the adhesion of the resin to the metal by more than 100%. No significant differences were found between the three bonding agents Silicoater, Sebond MKV and OVS.

Acrylic Resins↗