Biomedical subjects

G Schmalz

Publications and source records attributed to G Schmalz.

At least 19 recordsLinked to original sources

PubMed1990

[Determination of caries risk in federal soldiers].

Using Dentocult/Dentobuff the "caries risk" was determined in 102 adult test persons three times within a period of 44 weeks and correlated with clinical and radiological study results (Spearman rank correlation, multiple calculation of correlation and regression). The patients were given dental treatment as required during the study period. A close correlation was seen between the individual Dentocult measurements taken at different times, which speaks for relative constancy in these measured values in individual test persons. No significant correlation with the overall increase in caries was found and did not become apparent until cases of caries were categorised as primary, secondary and smooth-surface types. The correlation coefficient was, however, low at R = 0.2-0.4. The prognostic value of the Dentocult/Dentobuff system was at best about 50%. A connection between the caries risk test and clinical parameters became evident in the presence of localised retention. On the whole, however, it must be said that our studies do not show that this method makes it possible to prognosticate the caries risk in individual patients.

Adult↗

PubMed1990

[Marginal fit of ceramic and composite inlays in vitro].

Direct and indirect composite and ceramic inlays exhibit a space between inlay and tooth, which is filled with a luting composite resin. The aim of the present study was to evaluate the influence of the width of this space upon the quality of the marginal seal of the inlay system. The marginal quality of class II-inlays with small (0.2 mm) and large (0.4 mm) spaces was examined using quantitative SEM analysis and dye penetration. Regular class-II composite fillings served as controls. After thermal and mechanical loading the composite inlays with the wider composite layer showed more marginal gaps than both groups of ceramic inlays. The ceramic inlays did not show a significant deterioration of the margins. The least amount of dye penetration was observed in ceramic inlays with a wider composite layer at the interproximal cavity wall. Composite fillings showed more dye penetration than inlays.

Ceramics↗

PubMed1990

[Root canal therapy--clinical results].

Clinical and radiographic evaluations of root canal therapy indicated, that after correct patient selection endodontic therapy is technically feasible in most cases (even in posterior teeth). Only in few cases (3%) did symptoms of flare ups (5.4-13.4%) last for more than one week. This rate could be further reduced by additional measures, such as the local application of antibiotics and steroids. Long-term success rates for root canal therapy have been reported to range between 71 and 96%. The patient's age and the type of tooth affected had no effect on prognosis. Teeth with periapical resorptions displayed slightly lower success rates. Failures were primarily attributable to overfilling or inadequate instrumentation and/or filling. Root canal therapy should be part of an overall treatment plan including considerations of primary and secondary prevention as well as each patient's individual needs.

Humans↗

PubMed1990

[Clinical comparison of different cervical fillings after one year].

Cervical lesions in 38 patients were restored using composite resins (n = 57), the "sandwich-technique" (n = 64) or glassionomercement (n = 66). Immediately following insertion and 4, 8, and 12 months later, the restorations were examined clinically and in the SEM. Two composite fillings and one filling each of the two other types of restoration were lost. After one year the quality of the dentinal margins of the composite restorations was statistically (p less than 0.05) inferior to the two other methods. Margin quality in enamel was rated superior (p less than 0.05) with glassionomercement as against the other materials. Clinically, the composite filling yielded poorer results regarding marginal integrity and discoloration, although in general they showed superior esthetics. In restoring cervical lesions the use of glassionomercements or the "sandwich-technique" has definite advantages over composite fillings. For the evaluation of new restorative materials and techniques, SEM should be used in addition to clinical examinations.

Adolescent↗

PubMed1990

[In vitro growth of periodontal ligament fibroblasts between bone and root slices].

In a first experiment the proliferation and growth kinetics of periodontal ligament fibroblast monolayers generated from human healthy (HPDL) and diseased (DPDL) periodontia were compared. In a second experimental series a periodontal ligament-like space was developed by laying a root slice inside a bony ring slice on the bottom of a tissue culture petri dish and leaving a space of about 0.5 mm between both structures. HPDL cells showed a higher proliferation rate than DPDL cells. Growing into the space between the slices, the PDL cells built up a matrix which was composed of cells and fibrils. HPDL cells built up the matrix more rapidly than DPDL cells.

Adolescent↗

PubMed1989

The role of proteoglycans in collagen gel contraction by human gingival fibroblasts.

Fibroblasts generated from biopsies of normal gingiva contract collagen gels to a significantly greater extent than do fibroblasts generated from chronically inflamed gingiva. The present study demonstrates that proteoglycans play a major role in gel contraction, and that cells from the two sources differ greatly in their ultrastructural features and their capacity to synthesize proteoglycans. Fibroblasts from normal gingiva contained more rough endoplasmic reticulum and mitochondria, and they were more well-spread than cells from chronically inflamed gingiva. We observed a fine granular electron-dense lamina of material especially prominent around the cell processes and on the surface of the collagen fibrils. This material appears to be rich in proteoglycans since it stained with ruthenium red, a dye that binds to proteoglycans, and labeled in cultures incubated for 1 or 4 hr in medium containing 35S-sodium sulfate. Proteoglycans have the capacity to bind matrix components to one another and to cells, and thereby play a major role in gel contraction. Normal fibroblasts have a significantly greater capacity to synthesize proteoglycans, as manifested by label incorporation, that do cells from inflamed tissue, and this may account for their greater capacity to contract collagen gels in vitro.

Collagen↗

PubMed1988