Biomedical subjects

P Diedrich

Publications and source records attributed to P Diedrich.

At least 91 records · Page 5Linked to original sources

PubMed1990

[Limits of orthodontic treatment of periodontally affected dentitions].

Basically there are no exact metric limits in terms of probing depth or loss of periodontal attachment, up to which orthodontic tooth movement is possible. Each individual treatment plan depends on a great variety of factors and is limited particularly by biomechanical considerations (uncontrolled force systems, limited anchorage quality) and the risks associated with specific periodontal conditions (tooth/alveolar bone topography, sinus recessus, activity and prognosis of periodontitis).

Alveolar Bone Loss↗

PubMed1990

[Bodily movement of teeth in atrophic jaw segments].

This experimental animal study was conducted to evaluate the extent of bone restructuring after bodily movement of teeth into an area of atrophied alveolar bone. The measured values as well as the radiographic and histologic data indicate that partial or total bone restructuring occurs depending on the rate of tooth movement. In our experiment we observed marked bone formation at an average tooth movement rate of 15 microns/day, whereas no noteworthy bone formation occurred at higher rates of tooth movement (26-40 microns/day). Basically, an improvement in attachment is possible with bodily movement in atrophic alveolar bone. However, it is important to remember the delayed periosteal reaction when planning the mechanics to be applied.

Alveolar Bone Loss↗

PubMed1990

[Intrusion of periodontally affected teeth using a polyglactin-910-membrane (Vicryl)].

The present study was to determine, if the use of a Vicryl membrane following a full flap procedure and combined with subsequent orthodontic intrusion renders the formation of new attachment more predictable. In an animal experiment eight premolars with reduced periodontia were intruded. The findings were analyzed histologically, histometrically and radiologically. The results provided the basis for a new general classification of the formation of new cementum and bone substance. This classification may serve as a reference system for future studies. The combined orthodontic/periodontologic approach resulted in complete repair and functional restructuring of the destructed interradicular bone and may be a promising alternative in the treatment of furcation invasion. The proximal root surfaces showed less increase in attachment or even further bone loss. Histometric comparison revealed no significant differences between interradicular and proximal root surfaces.

Alveolar Bone Loss↗

PubMed1990

[Rates of root resorption in orthodontically moved, periodontally affected and healthy teeth].

The aim of this SEM-study was to obtain a quantitative analysis for comparing the extent of root resorption in orthodontically treated teeth, in teeth with reduced periodontium and in healthy teeth. By using a statistically valid method the highest amount of root resorption was established in orthodontically moved teeth. The teeth with loss of attachment showed a significantly higher amount of root resorption than healthy teeth. This finding complicates orthodontic treatment in teeth with reduced periodontal attachment.

Adolescent↗

PubMed1989

[Materials science studies on the soldering of different orthodontic wires].

In orthodontic technique both soldering and welding are standard methods for the application of auxiliaries and for the modification of force systems by joining wires of different cross-sections. Two cobalt-chromium alloys (Blue Elgiloy, Crozat) and an austenitic stainless steel alloy (Remanium) were soldered by an electrochemically generated hydrogen-oxygen flame forming an overlapped joint design. For characterization of the soldered joint testing procedures included microhardness tests, metallographic examination, tension-shear tests and surface analysis of the fractured joints by scanning electron microscopy. For any given soldering technique with an overlapped joint design the correct joint length is determined by the ratio t/s = 3 (t = overlapped length; s = diameter of the smaller wire).

Dental Alloys↗

PubMed1989

[Correlations of orthodontics and periodontics].

Periodontics and orthodontics are correlated with one other in many ways. For instance, periodontal conditions have to be considered in the orthodontic treatment of adults, special orthodontic measures are taken to enhance a periodontal treatment, and when periodontal surgery is performed for the prevention of relapse or the disimpaction of teeth. Dental practitioners working in the field of orthodontics should have a sound understanding of the biology and pathology of the periodontium in order to avoid causing periodontal lesions, or when lesions are present, how best to determine prognosis and differential treatment.

Adult↗

PubMed1989

[Microbial colonization and various cleaning procedures for orthodontic appliances].

The cleaning of removable appliances was analysed in three groups: 1. cleaning with tooth-brush/toothpaste, 2. self-acting cleansing agent, 3. ultrasonic treatment. In the same patient group identical plates were fitted each for one month and cleaned by the different procedures. The microbial population and the cleansing effects were analysed by scanning electron microscopy. The findings shows clearly, that the toothbrush alone is unsatisfactory for achieving effective decontamination in the hygiene-critical areas of the plates. In contrast to this cleansing tablets and ultrasonic treatment were more effective in plaque-accumulating areas. None of the cleansing procedures effected complete decontamination of the removable appliances.

Adolescent↗

PubMed1989

[Interaction between orthodontic tooth movement and hydroxyapatite ceramics].

A pilot study examined the clinical and histological effects of orthodontic tooth movement in hydroxyapatite-augmented ridges in animal models. Responses observed at the interface between the clinical root and the ceramo-osseous regeneration were negative: impairment of periodontal function had led to immobility and root resorption. On the basis of this experience one must advice against using this approach in humans at the present time. Further studies will be conducted to elucidate the relevant clinical questions.

Alveolar Ridge Augmentation↗

PubMed1988