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Biomedical subjects

M Grüner

Publications and source records attributed to M Grüner.

At least 19 recordsLinked to original sources
PubMed2004

[Design and testing of a novel measuring system for use in dental biomechanics--principles and examples of measurements with the hexapod measuring system].

A novel measuring set-up based on a hexapod system for use in dental biomechanics is described. It was specially developed to measure force/deflection characteristics of different dental materials and devices. The functionability and suitability of the system for use in experimental biomechanics were investigated in two different studies. In a first study the micro mobility of prosthetic telescopic crowns prior to and after simulated wear was determined to investigate the influence of wear processes on the stability of the anchorage elements and thus of prostheses. This study investigated the ability of the setup to load a specimen with high forces or torques of up to 100 Newton. The second study looked at the force/deflection characteristics of orthodontic anchorage pins used in orthodontics to additionally stabilize the anchorage unit, for example during molar movement. In this study specimens were loaded with small forces of less than 10 Newton, as are typically used in orthodontics. Using the setup, the deflection behaviour of these devices under high and low loading was measured at a resolution of approximately one micrometer or one angular second.

Biomechanical Phenomena↗
PubMed1998

The relevance of extracorporeal septoplasty in cleft nose correction.

The aim of this paper is to delineate the importance of the correction of the nasal septum when attempting to improve the nasal shape and function in patients with cleft lip and palate (CLP) deformity. The particular problems of the nasal shape in CLP patients are assessed. Various approaches for adequate correction are reviewed and discussed. The method of extracorporeal septoplasty is presented in detail. This method was used between 1982 and 1997 in 141 out of 332 CLP patients who required septoplasties and appears particularly suited for this purpose since it offers the possibility of reconstructing an almost normal septum. This is necessary in order to achieve both a functionally and an aesthetically good result. Our experience over the past 16 years confirms the advantages of this approach.

Adult↗
PubMed1993

[The effect of gamma radiation on the methionine and tryptophan content of soy protein products].

Effect of gamma irradiation on the content of methionine and tryptophan in soya protein products were investigated. Irradiation with doses of 1, 3 and 5 kGy caused significant (p = 0.05) decrease of methionine contents. Parallel with the decrease in methionine also the relative quality of proteins is lowered. Tryptophan content were significantly reduced (p = 0.05) at irradiation doses of 3 and 5 kGy. The relative decrease of methionine and tryptophan contents are significantly correlated (p = 0.05) with relative increase in amount of products by the irradiation induced oxidation of lipids; correlation coefficients were 0.576 and 0.715.

Gamma Rays↗
PubMed1991

[Content of available lysine in gamma-irradiated soybean products].

The content in available lysine of soya protein products irradiated in a 60Co-gamma cell were investigated. The results indicate that available lysine content and crude protein content at irradiation doses of 1, 3 and 5 kGy were unaffected at the 95% significance level. During 3-month storage the irradiated samples showed no significant (p = 0,05) changes of available lysine content. In samples with high content of lecithin, which were irradiated at 1 kGy as well as non-irradiated the content of available lysine was significantly (p = 0,05) reduced after 8-month storage; the other products as well as the at 3 and 5 kGy irradiated samples showed no significant decrease. Immediately after irradiation the microflora was significantly (p = 0,05) reduced. Under the effect of radiation treatment at 3 and 5 kGy the microflora was reduced to nearly 100% after 3-month storage.

Bacteria↗
PubMed1991

[Anterior guidance compared with curvatures of sagittal TMJ excursions].

The sagittal condylar paths of 17 healthy persons with class I occlusion were recorded by electronic axiography. Based on the radius values established for the geometry of each condylar path these could be compared with the protrusive facets of the incisors and the first premolar teeth. The results are important for our understanding of the movement profiles of the masticatory system. Correlations between the TMJ and the anterior teeth in terms of functional morphology were observed.

Dental Occlusion↗
PubMed1990

[Adhesive strengths of cast crowns with various types of cements].

In an in vitro study the adhesive strength of sand-blasted castings (gold alloy) was tested on human teeth prepared and finished in different ways. For cementation we used two glass ionomer and one phosphate cement. On the surfaces treated with carbide finishing instruments the force required for separating the crown from the tooth was about 1.9 N/mm2 for Ketac-cem, about 2 N/mm2 for Fuji Ionomer, and about 1.8 N/mm2 for Harvard (a zinc oxide phosphate cement). Compared with this, the values obtained for dentin surfaces pretreated with fine diamonds (red ring) were 1.5 N/mm2 for Ketac-cem, 1.6 N/mm2 for Fuji Ionomer, and 1.9 N/mm2 for Harvard. The measured differences between the various types of cement were statistically not significant.

Crowns↗
PubMed1990

[Pre- and post-eruption effects on the functional morphology of the articulating structures].

Profile traces of latero- and protrusive facets of subjects with class-I-occlusion showed characteristic regular patterns in curvature and angle to the occlusal plane. There was no significant correlation between the laterotrusive surface profiles and the corresponding transversal movement of the condyle which was recorded electronically in 3 dimensions. Curvature morphology was plotted as a function of tooth eruption, development of the dental hard tissues, and tooth wear. In conclusion the results were applied to comprehensive occlusal restorations.

Dental Arch↗
PubMed1989

[Changes in the tryptophan content during the technological manufacturing processes of several wheat flour products].

The change of tryptophan contents in proteins of bread and cookies under technological processing conditions were investigated. Tryptophan contents in all cookie samples were noted to be significantly (p = 0.05) reduced in relation to corresponding dough. The relative decreases are significantly correlated with fat content and the degree of unsaturation of fats in the dough of cookies (r = 0.802 and r = 0.777, p = 0.01), independently of various physical parameters during different cookie samples' processing. Tryptophan decrease in proteins of bread during baking was not significant.

Bread↗
PubMed1989

Relationship between protein nutritive quality and technological property parameters of wheat flour.

The biological value of proteins as well as their importance for the technological quality of wheat flours have been extensively researched. Apart from the other factors, gluten content, structure and functional characteristics are responsible for the flour's technological properties. Functional properties of gluten complex and thus also rheological properties of flour are influenced by the specificity and intensity of interactions among individual protein fractions and likewise of protein interactions with other flour components. Rheological properties of flour and quality parameters of bread are changed to a greater or lesser extent, among other, by addition of free amino acids. The purpose of this work was to explore the relationship between certain essential amino acids of wheat flour and the parameters of flour rheology and bread baking quality.

Absorption↗
PubMed1989

[Comparative studies on the morphology of the curvature of the protrusive paths in anterior and posterior teeth].

The occlusal surfaces of 20 class I probands were recorded during protrusion with an electronic profilograph. Using a circular template, a definite radius could be attributed to each of the recorded curvatures. The radii and angles determined relative to the occlusal plane showed characteristic regularities. Thus, the radii of the anterior teeth are longer than those of the posterior teeth. The longest radius was generally found for the canines. The same tendency, although less pronounced, was observed with the angles. These phenomena can be explained by the fact that the masticatory system involves both "biting" and "grinding". Evolutionary and embryological theories have also been included in the discussion.

Dental Occlusion↗
PubMed1989

[Cervical discrepancies and closeness of marginal fit of full cast crowns in correlation with the luting agent used].

In an in-vitro study 75 extracted teeth were prepared with a chamfer and a 12 degree convergence angle. After corrective impression taking and preparation of the dies accurately fitting caps were made of "Stabilor G" alloy. The marginal defects were measured at 4 points on each tooth under the light-microscope before and after cementing with three different luting agents. Before cementation the mean values and standard deviation of the cervical discrepancies were 105 +/- 43 microns. The crowns fixed by means of zinc oxyphosphate cement (Harvard) exhibited marginal defects of 142 +/- 33 microns, those fixed with Fuji-Ionomer type I glass polyalkenoate cement had 159 +/- 20 microns, and the crowns cemented with Ketac-Cem had 127 +/- 6 microns. After exposing the specimens to thermal cycling, additional data on the sealing capacity of these cements could be obtained which showed zinc oxyphosphate cement to have the most favorable properties.

Cementation↗
PubMed1981

[Changes in the biological protein value of wheat grain caused by manufacture into flour and gluten].

The authors determined the amino-acid composition of the proteins of whole wheat grain, flour and gluten, and calculated the biological protein values of these products from the data obtained. The decrease in the contents of the single amino acids was as follows: flour, 8--13% (as compared to whole grain); and gluten, 2--5% (as compared to flour). The decrease in the biological protein value according to Mitchell was: wheat flour, 5% (as compared to whole grain); and gluten, 8% (as compared to flour). The decrease in the biological protein value according to Oser was: flour, 9% (as compared to whole grain); and gluten, 26% (as compared to flour).

Amino Acids↗