PubMed Health⌕ Search

Biomedical subjects

H W Kersten

Publications and source records attributed to H W Kersten.

At least 19 recordsLinked to original sources
PubMed2007

Development and implementation of new educational concepts in a dental curriculum.

The Academic Centre for Dentistry Amsterdam introduced a fully renewed 5-year dental curriculum in September 2003. In this article, the educational principles and didactic choices that form the basis of the curriculum development are presented and attention is given to the process of development and the implementation strategy that constitute such an important part of the success of introducing a new curriculum. Special characteristics of the new curriculum are the clinical training practice, professional conduct, the elective profiles and academic education. In clinical practice, groups of students from different levels run a group practice in which they learn to work together, delegate tasks, solve clinical problems and apply evidence-based dentistry. In the new curriculum students learn to conduct themselves as professionals. In the third and in the fifth year, students choose an elective profile oriented, respectively, on research and on clinical knowledge and skills. Academic education is an important spearhead in this curriculum in which students not only learn why research is important to dentistry but also how dentists can use research to their own benefit. In development and implementation, a stepwise approach was used in which as many people as logistically possible were involved.

Competency-Based Education↗
PubMed2001

[Dental curriculum and team treatment concept].

The changing oral situation in the Netherlands, the upgrading of the dental hygienist training and the introduction of the bachelor and master degree in the Dutch higher education system asks for a new dental professional: the oral physician. To prepare the oral physician for his role as leader of a dental team several changes and new developments are necessary in the existing dental curriculum.

Curriculum↗
PubMed1997

[Dentist and title. The importance of science for dentistry].

Dentistry as a science is relatively new. In the Netherlands dental research has developed progressively during the last decades. This however, has only slightly influenced the training of dental students. In this article the interest of science to dentistry and dental training is explained from the point of view of dentistry as a developing science, from the point of view of the problem solving clinician and from the learning student.

Clinical Competence↗
PubMed1994

[Dental education: a new approach].

A new curriculum will be introduced in the Academic Centre for Dentistry Amsterdam (ACTA) in September 1994. Besides adaption of the contents of the curriculum, a new philosophy in teaching will be adopted. In this article the educational principles and conditions are discussed which have to result in modern student centered teaching. In addition, a concrete illustration is given of the effects this will have on the ACTA curriculum.

Curriculum↗
PubMed1990

Quantitative microleakage study on a new retrograde filling technique.

An in vitro endodontic leakage model was used to compare the sealing ability of conventional retrograde amalgam fillings with a new retrograde filling technique by measuring dye leakage quantitatively. The new technique consisted of retrograde preparation of the root canal using the Endocursor, an endodontic handpiece. The canal was then filled with sealer and injection-moulded gutta-percha, using either the Hygenic Ultrafil system or the Unitek Obtura method. In both cases the gutta-percha was vertically condensed and subsequently cold-burnished. The two experimental groups and the amalgam group each consisted of 20 extracted human canine teeth and lower premolars. The results were analysed statistically by ANOVA and a Student-Newman-Keuls multiple comparison test. After 1 week at 37 degrees C, very little leakage was observed in the amalgam and gutta-percha groups. After a second week, during which leakage was enhanced by gas pressure, leakage in the amalgam group was significantly greater than that in the gutta-percha groups (P less than 0.01). There were no significant differences between the two experimental gutta-percha groups. It is concluded that the new retrograde filling technique causes less leakage than the conventional amalgam retrograde filling technique in an in vitro model.

Analysis of Variance↗
PubMed1989

Particles and molecules in endodontic leakage.

It is assumed that above a critical level, microleakage causes periapical disease and jeopardizes periapical tissue repair. The purpose of this investigation was first to find out to what degree obturation prevents leakage of bacteria-sized particles or large protein molecules, and second if leakage of the commonly used dye methylene blue is comparable with that of a small bacterial metabolic product of similar molecular size. Sections, 9 mm long, obtained from 46 extracted human incisor roots had their root canals prepared in a standardized manner and obturated in four experimental ways using gutta-percha. The root sections were mounted in the middle of tubes that were closed at both ends with rubber membrane stoppers, which permitted sampling from the apical reservoir. The coronal reservoir was filled with a solution of 1 mg/ml latex beads, 4 micrograms/ml endotoxin, 0.5 per cent butyric acid, 0.1 per cent valeric acid and 0.1 per cent methylene blue water. After 1 and 2 weeks, samples were taken from the apical reservoir and tested for the presence of latex beads by phase-contrast microscopy, for endotoxin with a limulus lysate test, for butyric acid with gas-chromatography and for methylene blue with spectrophotometric analysis. Leakage of bacteria-sized particles and large-sized protein molecules could be prevented only when both sealer and pressure were used in obturating root canals with gutta-percha. Leakage of butyric acid proved to be comparable with leakage of methylene blue; microleakage of these small molecules could not be prevented in this study whatever method of filling was used.

Dental Leakage↗
PubMed1989

[Root canal filling].

Making an adequate root canal filling, a biocompatible and hermetically sealing filling just to the apical constriction, is a relatively difficult and time-consuming task. A variety of materials and techniques are available. In this article an overview is given of some well-known materials and techniques. It is concluded that those techniques have to be selected on which the dentist can rely and with which he gets consistently radiographically adequate root fillings and clinically favourable results. The choice of root filling in practice will depend on the nature and shape of the canal to be treated. For this reason it is advised that the dentist masters several techniques.

Humans↗
PubMed1981

Thiocyanate as a cofactor in myeloperoxidase activity against Streptococcus mutans.

Inhibition of glycolysis of some oral bacteria was established in vitro by an antibacterial system, consisting of myeloperoxidase, H2O2, and a cofactor. When thiocyanate was used in physiological concentration as a cofactor, the system acted (at low pH) bactericidally on Streptococcus mutans, as indicated by the determination of viable counts. However, at neutral pH, the glycolysis of Streptococcus mutans was inhibited, while its viability remained unaffected. The possible role of such a pH-dependent antibacterial system in the oral cavity is discussed.

Androstenedione↗