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Biomedical subjects

L Huck

Publications and source records attributed to L Huck.

13 recordsLinked to original sources
PubMed2006

Evaluation of an antimicrobial and fluoride-releasing self-etching primer on the shear bond strength of orthodontic brackets.

The enhanced risk of dental caries is one negative side-effect of fixed appliances. A new antimicrobial and fluoride-releasing self-etching bonding system (Clearfil Protect Bond) has been introduced in restorative dentistry and clinical studies have already shown the potential for this primer to be used clinically with effective antiplaque properties. Therefore, this in vitro study was conducted in order to evaluate the new primer in comparison with a conventional bonding preparation. One hundred and twenty extracted human teeth were randomly divided into three groups of 40 specimens each (20 incisors, 20 premolars). In group 1 a conventional bonding procedure was used (etching, Transbond XT), in group 2 the new primer was used according to the manufacturer's recommendations when bonding to intact enamel, while in group 3 the new primer was used without prior etching. Shear bond strength (SBS) was measured with a universal testing machine and the adhesive remaining after debonding was determined using an optical microscope at x10 magnification. The adhesive remnant index was used in order to assess the mode of failure. No enamel fractures were detected in any of the specimens. In all groups acceptable bond strengths were observed. The only statistically significant difference (P = 0.004) was found for the incisors in group 2, which showed the highest mean SBS (17.46 MPa). Considering the acceptable bond strength and the mode of failure, use of the new primer without prior etching is recommended in patients with fixed appliances. Further in vivo studies will be carried out in order to evaluate clinical performance.

Anti-Infective Agents↗
PubMed2000

Postretention changes in canine position. Results of a long-term follow-up.

The aim of the present study was to evaluate sagittal, vertical and transverse changes in canine position and a possible correlation with relapse of lower anterior crowding. From a sample with a long-term follow-up of 15.7 +/- 4.4 years after treatment, patients with a full dentition were enrolled in the study. Post-treatment and long-term follow-up casts of 117 patients were measured and statistically analyzed. A decrease in intercanine width was found between post-treatment and long-term follow-up records, with more lingual inclination of the mandibular canine axis in the transverse plane. There was a significant correlation between maxillary and mandibular canine inclination. Concomitant changes were an increase in lower anterior crowding and a decrease in mandibular intercanine width. Relapse of anterior crowding has a multifactorial etiology. The results of this study suggest a possible influence of the canines. Functional causes in particular might have a profound influence and should be considered during treatment planning.

Adolescent↗
PubMed1999

Bond strength of a fluoride-releasing bracket adhesive. Experimental study.

The aim of the study was to examine a new fluoride-releasing light-cured filling composite for its bonding and debonding qualities when used as a bracket adhesive. The material investigated was a hybrid composite containing a chemically modified fluoride apatite, which is claimed to provide the enamel with phosphate, calcium, and fluoride ions in the presence of an acid pH, recharging its resources of these ions through fluoride-containing toothpastes used in daily oral hygiene. Concurrently suitability as an enamel conditioner was tested in a new self-etching primer, which does not require water rinsing but is gently air dried instead. For comparison a conventional light-cure single-component adhesive was used together with 37% orthophosphoric acid. After application of the respective conditioners, mesh-backed metal brackets were bonded to 20 human premolars in each of the 2 adhesive groups and subjected to a shear test. Bond failure location was evaluated using the Adhesive Remnant Index (ARI). Average bond strength of the experimental bracket adhesive and the conventional etchant was 8.96 MPa. Conditioning with the self-etching primer led to a decrease of mean shear bond strength values to 6.55 MPa. Highest bond strength was determined in the control group (12.19 MPa). The bond strength results obtained in the shear test recommend the new material as a bracket adhesive to be used with orthophosphoric acid for etching.

Analysis of Variance↗
PubMed1983

[Whipple's disease with severe gastrointestinal hemorrhage].

A case report is given of a 54 year old male patient, who had acute, relapsing, life threatening episodes of gastro-intestinal bleeding caused by hemorrhagic gastroduodenitis associated with Whipple's disease. The diagnosis was established by histological examination of duodenum biopsies, which contained the pathognomonic PAS-positive macrophages. The gastroduodenitis healed after treatment with tetracyclines und bleeding stopped consequently. Clinical, pathological, radiological and clinical chemistry findings of patients with Whipple's disease are discussed on the basis of literature.

Duodenum↗
PubMed1983

[Clinical relevance of the "cockade phenomenon" in abdominal ultrasonic diagnosis].

The ultrasonic diagnosis "cockade sign" in patients with unexplained abdominal complaints was investigated by means of endoscopy and X-ray studies of the gastrointestinal tract. The following final diagnoses were established: gastric cancer in 24 patients (16,2%), colonic carcinoma in 31 patients (21%), intraabdominal tumor without infiltration of the GI-tract in 19 patients (12,8%), inflammatory bowel disease in 35 patients (23,6%). In 39 patients (26,4%) no inflammatory or neoplastic process of the GI-tract could be found. Most of these patients were suffering of a spastic colon. If a tumor of the gastrointestinal tract can be made visible by ultrasonography, this may shorten the diagnostic procedure. However, ultrasonic investigation of the abdomen cannot exclude an abdominal inflammatory or neoplastic process. Therefore, it is only useful as a screening procedure.

Abdomen↗
PubMed1981

[Sonographic diagnosis in cholestasis (author's transl)].

In a prospective study, sonographic diagnosis was compared in 156 patients having jaundice or showing clinico-chemical signs of cholestasis, with the final diagnosis obtained via endoscopic-retrograde cholangiography, percutaneous transhepatic cholangiography, surgery or autopsy. The results show that in almost 90 per cent of the cases it is possible to differentiate between intrahepatic and extrahepatic cholestasis via sonography. The limitations of sonography concern the identification of prepapillary bile duct concrements which were present in 30 per cent of the patients. Hence, in most cases it was not possible to supply aetiological pointers towards determining the cause of the bile flow disturbance.

Autopsy↗
PubMed1980

[Extraintestinal manifestations of Crohn's disease].

Specific extraintestinal manifestations of Crohn's disease are rare except the involvement of the anal region. Only few case reports have been published concerning Crohn's disease of the lips, the mouth, the hypopharynx, the skin, urogenital tract, bone and joints. However, Crohn's disease of the anal region is of great significance. About 30 % of the patients develope fistulae, fissures, abscesses and perianal edema. The anal disease is often a first important and often missed sign of intestinal M. Crohn. Biopsy and histological investigations of the diseased tissue reveals typical histological changes in up to 60-70 % of the patients with anal disease.

Bone Diseases↗
PubMedDate not supplied

Oncology applications of flow cytometry.

The application of flow cytometry in evaluation of neoplasms is reviewed, with emphasis on DNA content analysis and surface-membrane antigen analysis. By measuring total nuclear DNA content one can determine the ploidy status and S-phase fraction of tumor cells. Aneuploidy, an abnormal DNA content, is a marker of malignancy and often a predictor of poor prognosis in a number of tumor categories. S-phase fraction reflects the proliferative activity of the tumor and is therefore related to the aggressiveness of the tumor. Surface-membrane antigen analysis of hematologic malignancies using monoclonal antibodies is useful in determining lineage and differentiation of tumor cells. This information is helpful in diagnosis and monitoring of patients and also has prognostic values. The flow cytometry is a new tool for the management of cancer patients because of its role in diagnosis, monitoring, and prognosis of tumors.

DNA, Neoplasm↗