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Biomedical subjects

F Lutz

Publications and source records attributed to F Lutz.

At least 289 records · Page 16Linked to original sources
PubMed1977

[Follow-up studies on 15-month-old adhesive fillings].

Clinically, 450 Adhesive Restorations have been reexamined 15 months after insertion. Several of these restorations were also evaluated by SEM. The principles of cavity preparation for adhesive fillings deviate from those postulated by G.V. Black. They aim at a micromethanical retention of the restorative material to the tooth structure. A considerable amount of sound tooth structure can be saved. The combination of cavity design with enamel conditioning and the use of a low viscosity sealant prior to the insertion of the composite (Caulk Nuva System) resulted in restorations showing no microleakage and a perfect marginal adaptation. Their retentive strength seems to be sufficient as well as the durability of their excellent marginal properties. Pulpal responses to the application of etching agents were avoided by covering the dentin with an acid resistant base. Splinting of teeth using a strictly adhesive method without cavity preparations failed in more than 50%. The high rate of composite discoloration (43%) was probably due to factors inherent in the restorative material itself.

Adhesiveness↗
PubMed1977

[Oral health for everyone--an unattainable goal? Analysis of a questionnaire among 1200 Swiss recruits].

The attitude of 1085 Swiss military recruits towards the dentist and dental care, their knowledge of periodontal disease and its prevention, the incidence of smoking and the frequency of eating sweets as well as interest in their own teeth in general was determined by use of a questionnaire. The results showed a positive attitude on the part of the participants towards their own teeth and a definite motivation for good oral health. The oral hygiene habits of only a minority could be classified as sufficient, the knowledge of periodontal disease and its prevention were limited. Smoking and eating sweets were found to be widespread. It can be stated, therfore, that hygiene instruction for improvement of oral health by the dental profession as well as motivational efforts towards general health education at home and at school were unfortunately unsatisfactory.

Adult↗
PubMed1977

[Surface analysis of 2 composite filling materials after various methods of finishing and sealing].

The surface quality of 2 composite filling materials (Adaptic with coarse hard quartz fillers and Cosmic with fine softer glass fillers) was evaluated using profilometry, scanning electron microscopy and light reflectometry after finishing with experimental diamond discs, 3M discs, corundum discs, polishing paste and also after sealing. Plaque formation on standardized surfaces of both composites was photographically recorded in 20 subjects. The sealed surfaces and the surfaces finished by the matrix alone were approximately 10 times less rough than after finishing procedures. Under in vivo conditions they reflected the most light, for both composites. The sealer failed to cover the whole composite surface. The unfinished and sealed surfaces lost their shine 3-7 days after placement in the mouth. Decrease in reflectance was independent of mechanical oral hygiene procedures. There were no significant differences in the roughness produced by the various discs on Adaptic surfaces. Diamond discs with particle size 1-3 micrometer resulted in least surface roughness and were the only instruments not destroying the filler particles of either composite. 3M discs and the rough corundum discs caused significantly more surface roughness of the Cosmic surface. Reflectometry showed that the finishing methods unfavourably affected composite surface smoothness. Among all finishing methods polishing paste produced the highest reflection value on the Cosmic surface. Adaptic surfaces were always associated with more plaque formation than Cosmic surface after all finishing methods.

Composite Resins↗
PubMed1977

[Adpatation and marginal fit of thixotropic composites and syringe system composites. In vitro findings].

In a dye penetration test and a scanning electron microscopic evaluation MOD-restorations made of a thixotropic material (ZKP-A-5(2)) and of two syringe system composites (Concise-Capsule-Composite3, Compocap-S4) were investigated with respect to microleakage and marginal adaptation. These materials did not reveal better marginal micromorphology than a comparable two-paste composite system (Concise3); Compocap-S showed markedly less microleakage. The quality of marginal adaptation, however, was improved to 52% when a low viscosity sealant (ZKP-A-2(2), Concise Enamel Bond3) was applied before insertion of the restorative. A sealant pretreatment is therefore compulsory in thixotropic and syringe packed composites as well. The perfection reached with these composite brands is equal to that of adhesive restorations made of Concise or Adaptic5 [6,7]. Restorations performed with new, complete composite systems (Nimetic6, GC's Epolite 100/Epobond7) revealed moderate results when compared to standard materials like Concise or Adaptic [6,7].

Composite Resins↗
PubMed1977

[Evaluation of 16 months old variously fashioned incisor fillings].

The influence of the cavity preparation form, enamel conditioning, and application of a low viscosity sealer upon marginal adaptation and microleakage of anterior teeth proximal composite restorations was investigated in vivo. Restorations inserted using the principles of Adhesive Restoration showed the best results. Experimental adhesive fillings placed into minimally prepared saucer-shaped cavities with no macroscopic dentin retention demonstrated likewise satisfactory results because of their small volume. Definitely inferior marginal adaptation and increased microleakage were obtained with other restorative techniques. Trace areas of etched enamel could be observed after 16 months in those cases where enamel conditioning was not followed by a sealer application. The utilization of a sealer, therefore, improves not only the marginal adaptation of the composite material but in addition offers a protective seal to the previously conditioned enamel surface. Once the adhesive restoration is completed, it is recommended that a fluoride solution be applied to all enamel surfaces in the operational field. This fluoride treatment results in the formation of extremely high concentrations of fluorapatite in enamel areas which might have been inadvertently exposed to etching solutions during the procedure and not sealed or covered by composite material.

Dental Restoration, Permanent↗
PubMed1977

[Core build-ups from composites--evaluation of the technics of application].

The advantages and disadvantages of composite materials when used in direct core restoration of endodontically treated teeth is discussed. With the aid of dye penetration tests and scanning electron microscopy, in vitro fabrication of gold and amalgam cores were compared to those of 3 different composite core techniques. A compression technique used in the application of composite to the Radix -anchor post was judged successful. Neither modification of preparation nor application of a sealer before composite insertion improved margin adaptation or reduced microleakage of restoration margins. Acid etching of dentin definitely decreased marginal quality; therefore, for core construction using composites, the acid etch technique is not indicated. The proper use of composites is superior to gold and comparable to amalgam in core fabrication of endodontically treated teeth, when evaluating marginal adaptation and the reduction of microleakage at the composite-dentin interface.

Composite Resins↗
PubMed1977

[Effect of the shape of the cavity and the sealant system on the adaptive quality of the proximal anterior filling margins].

The influence of different cavity preparation and the use of a low viscosity sealant on the marginal adaptation and microleakage of class III composite restorations was investigated in a dye penetration and a SEM-study in vivo. In 9 subjects with 4 restorations each, different forms of dentin cavities and enamel preparations were performed. In 3 out of 4 cavity types a low viscosity sealant was applied prior to the insertion of the composite material. Replicas of the restorations after 30 min, 15 and 120 days were examined by SEM (magnification 400X). Marginal areas 1 h, 15 and 120 days after restoration placement were coated with a fluorescent permeating dye, flushed with water, dried and photographed under UV-light. The micromorphological and in vivo permeation investigations have demonstrated that restorations with no marginal leakage and with perfect marginal adaptation could be achieved when using a sealant composite system with a new cavity design, the "adhesive preparation". Furthermore the retentive strength of the "adhesive restoration" which has no macroscopic dentinal retention was largely sufficient.

Acid Etching, Dental↗
PubMed1977

[In vitro evaluation of the adaptation and quality of the margins in various composite systems].

Microleakage and marginal adaptation of different composite brands (Epoxydent, Restodent, Cosmic) in conventional and adhesive MOD-cavities have been investigated in an in vitro dye-penetration and scanning electron microscope study. The results were compared to those of a standard composite brand (Adaptic). Unrelated to the type of cavity and enamel etching procedures Epoxydent and Restodent revealed moderate results only. When the use of a sealant was omitted prior to bulk placement Cosmic showed the best adaptation. Priming (Cosmic Bond) was found to impede microleakage but not to influence marginal adaptation. The superiority of the adhesive restorations that had been performed with the Adaptic and the Concise system [4] is a result of the combination of these composite materials with a sealant and the new cavity design.

Composite Resins↗
PubMed1977

Endosteal oral implantology: two-year results of mobility and hysteresis measurements; A human study.

Clinical experience with tooth mobility measurements for assessment of periodontal health was employed in evaluating endosteal implant status. Mobility and hysteresis measurements of 14 implants in 11 patients were carried out regularly during a 2-year period. Immediate postsurgical implant post displacement was 5 hundreths of a millimeter (5.10(-2) mm). After 1, 6, and 24 months, mobility had increased to 13, 21, and 54.10(-2) mm respectively. Viscoelastic recoil patterns were recognized as diagnostic indicators of profound changes in the biophysical properties of periimplant environment.

Dental Implantation, Endosseous↗
PubMed1977

[The effect of fluoride application following enamel etching on the adaptation and adhesiveness of adhesive fillings].

The application of fluoride to etched enamel and the subsequent influence upon the marginal adaptation and retention of adhesive restorations was examined in vitro. Results showed that amine fluoride (F- = 1.15%, I.E. 0.01%) and 8% SnF2 (F- = 1.94%) did not affect wetting of the conditioned enamel by sealer and composite material. However, a reduction in retentive potential evidenced by a partial loss of the restoration feather margin during circulation bathing was observed. Consequently, during adhesive restorative procedures, a fluoride treatment of etched enamel prior to sealer application and composite insertion is contraindicated. Upon completion of adhesive restorations a fluoride application, for example Elmex Fluid, to the entire operation field is, however, recommended.

Acid Etching, Dental↗
PubMed1976

[The development of the perfectly adapted MOD composite filling material with tight marginal fitting in vitro findings].

Class II Adhesive Restorations have been realized with composites under laboratory conditions. They show a perfect marginal adaptation and no microleakage at the tooth/restoration interface. These properties were obtained a) with a new cavity preparation, b) by application of a low viscosity sealant prior to the placement of the bulk of the composite material. The Adhesive Restoration compared favorably with conventionally prepared restorations. Nevertheless, enamel conditioning with acid and the use of a low viscosity sealant in conventionally prepared class II cavities resulted also in some improvement of marginal adaptation.

Acid Etching, Dental↗
PubMed1976

[Cracks in the dental enamel caused by sensitivity testing with CO2 snow and dichloro-difluoromethane--a comparative in vivo study].

With the aid of permeating dye and standardized fluorescence UV-photography, the reaction of subjects and enamel to the application of two pulp vitality testing methods (frozen carbon dioxide and Frigen -pellets) was examined. The enamel lamella system, the diffusion of temperature changes through the tooth crown and the thermodynamic pattern of enamel and dentine are described in detail. Structural changes of enamel as well as the subject's reaction times to a cold stimulus during the vitality tests are documented and the data are compared. Frigen caused less enamel changes than did frozen carbon dioxide. The subject's reaction times were similar for both methods. There were no differences between the methods with regard to the number of reopened, extended and newly created enamel fissures. However, the length, width and depth of these fissures proved to be less pronounced for Frigen than for carbon dioxide. Clinical implications of the results are discussed.

Cold Temperature↗
PubMed1975

[Swelling and loss of potassium in perfused livers following the influence of the vapours of carbon tetrachloride, chloroform and halothane on the perfusion medium (author's transl)].

Erythrocyte free perfused rat livers were treated with vaporous carbon tetrachloride, chloroform and halothane by equilibration in the oxygenator system. The potassium loss, the amount of swelling and the alteration of the perfusion rates were measured during the experiments as criteria of acute toxicity. In contrast to the well known behaviour of perfused livers during the intoxication with phalloidin the amount of liver swelling did not marekdly depend on the perfusion rates in acute CCl(4) poisoning. The mechanism of swelling must be different in both intoxications. Exposure of perfused livers to high concentrations of CCl(4) for several minutes only produced a marked K-+-loss within a short time. This injury could not be fully compensated after finishing the exposure. Dose response diagrams are presented for carbon tetrachloride, chloroform and halothane by use of the following criteria: potassium loss, swelling (increase of wet weight) and perfusion rates (ml.min-1.g-1). As total doses the amounts of solutes vaporized during the exposition were listed. In these diagrams chloroform appears to be more toxic than halothane. CCl4 occupies a middle position between chloroform and halothane. The course of dose response diagrams of halothane is different from those of CCl(4) and CHCl(3). The halothane diagrams increase critically at high doses, whereas the courves for CCl(4) and CHCl(3) rise continuously. With respect to effects on the hepatic microcirculation halothane seems to be less toxic than CCl(4). The results are discussed on the basis of the periods of exposition and the maximal concentrations of the solutes in the perfusion medium. With respect to these data CCl(4) is much more toxic than CHCl(3) and halothane. On the other hand there is no marked difference in acute hepatotoxicity between CHCl(3) and halothane.

Acute Disease↗