Odontostomatologike proodos最新文献

The cause, the frequency, the complications and the surgical operation of impacted teeth is always an interesting subject of study and research. The purpose of this investigation was to determine the frequency and the kind of the teeth in the multiple impaction to Greek population. The material of this study was 1740 Greek (870 men and 870 women) over 20 years old. The results were: The percentage of patients with three or more impacted teeth was 11.37%. The 45.96% of these patients had 4 impacted teeth (P less than 0.0001), the 33.84%) had only 4 impacted wisdom teeth and 40 patients (20.20%) three. In the 53.03% of the cases presented only 3 or 4 impacted wisdom teeth and in the 30.81% of the cases 2 impacted wisdom teeth and other impacted teeth. The greatest percentage (82.83%) of the cases of multiple impactions comes from different impacted teeth. The greatest percentage (71.21%) of cases of multiple impactions was found in the posterior region of the jaws.

Animal models have been used extensively in biomedical research. The choice of the most appropriate model for a given research project is fundamental and depends upon specific characteristics of the animal. In the field of Preventive Dentistry the rodent species possess certain advantages which make them extremely useful in caries research and in dental plague pathogenicity. In caries research, rats have been used successfully to study anticaries efficacy of chemical agents, immunization, cariogenicity of diet, maturation of enamel and bacterial involvement in caries process. In this paper the dental characteristics of the rats are discussed emphasizing on the structure of their teeth, oral flora and composition of the saliva. Some of the experimental methods and procedures commonly used for microbial sampling, caries scoring and preparing diet are also described. In addition, an emphasis in given to certain experimental variables, which if not identified and strictly controlled, can attribute to a great variability and inaccuracy of the results. Finally, a basic experimental design for animal caries tests is suggested. In the last few decades, progress in caries research has substantially resulted from the utilization of the animal model system which have enabled examination of various facets of this disease under controlled laboratory conditions. The knowledge gained so far has been successfully applied on man with regard to diagnosis, treatment and prevention on dental caries.

The development of internal stresses in denture bases, during the procedures of curing, finishing and polishing is a very important factor and the power of these stresses is often of a remarkable level. In this article there are described the cases in which stresses are possible to develop inside the denture bases during the various processes of curing, finishing and polishing of the dentures as well the methods which are used to reduce their results on the finished dentures.

In this article, there are described within the limitations of the given space, the problems arising during the procedure of curing of complete dentures as well as the methods available for overcoming these problems is a satisfactory way. Overcoming these problems would have a positive result on delivering from the flasks dentures which will dispose bases which such mechanical abilities sufficiently capable to resist in the mechanical stresses, during the function of chewing.

Interparticle spacing has been long recognized as a very important parameter in the design of composite resins, especially for those placed in the posterior region. The purpose of this study was to assess the interparticle spacing in seven posterior composite resins (Ful-Fil, P-10, P-30, Herculite, HSCUF-experimental, Estilux Posterior, Estilux Posterior XR1). Interparticle spacing was varying from 0.28-2.99 microns (Underwood method) to 0.34-3.40 microns (Fullman method). Laser diffraction particle size analysis was found inefficient for application in dental composite filler technology. In the tested materials the following types or reinforcing fillers were identified: SiO2, BaO, ZnO and AlSiO4.

The margin's location of full coverage crowns is one of the most important factor susceptible to failure both biologically and mechanically. Most of the investigative proof shows that supragingival margins are kinder to gingivae than are subgingival margins. However clinical practice teaches and shows that supragingival margins are not always possible. For this reason in this study authors suggested intrasulcular margins. Of course all the factors of successful preparation is taken into under serious consideration. The related literature is also reviewed and the concept of "biological width" is presented.

Growth is a complex phenomenon that is affected not only by growth hormone but also by thyroid hormone, androgens, glycocorticoids and insulin. It is also affected by extrinsic and genetic factors. In humans there are two periods of rapid growth, the first in infancy and the second in late puberty just before growth stops. The first period of accelerated growth is partly a continuation of the fetal growth period which is not influenced by the presence of growth hormone. The second is a period in which hormones from the gonads and the adrenal glands combine with growth hormone to produce the adolescent growth spurt. As growth is one of the major factors influencing the plan and results of orthodontic treatment, the authors of this paper attempt a vast review of the factors influencing human growth classifying them into 3 main categories i.e. endocrine glands, heredity and environment, but also evaluating, as well, the combined implications of both genetic and environmental factors.

In this paper we presented the different theories and opinions regarding the development of pain. After a very brief historical review including the ideas of Homer, Hippocrates, Aristoteles, St. Thomas Aquinas, we reviewed the 19th century's theories including Whytt, Brodie, Inman and Austie. From the modern period we emphasized the "gate theory" introduced originally by Melzack and Well. The psychological aspects has been also examined and the patient as "a dental patient" also described.

The objective of this in vitro study was to evaluate the microleakage in extensive class II preparations in extracted human third molar teeth restored with a visible light-cured composite resin (Visio-Molar) used in conjunction with a low viscosity bonding resin (Visio-Bond) and three cement linings (Ca(OH)2, polycarboxylate cement and glass ionomer cement). Half of the restored teeth were subjected to temperature cycles in water between 5 degrees C and 55 degrees C for 24 h and half were left in distilled water at 37 degrees C for 24 h respectively. The restored teeth were immersed in a fluorescein dye solution and after sectioning the restorations, dye penetration at the restoration tooth interface was assessed and quantified using an optical incident fluorescein microscope. The results showed: 1. Microleakage was observed at the cervical wall of all the restorations. 2. No significant difference in marginal microleakage was found when the restored teeth were subjected to thermal cycling treatment (p greater than 0.05). 3. The use of a glass ionomer cement lining significantly (p less than 0.001) reduced the extent of cervical marginal leakage.

The demand for an acceptable appearance, including a natural and attractive smile, has nowadays a great effect on clinical practice. More patients than ever are requesting various types of cosmetic dentistry in order to improve their smile. The clinical practitioner has to deal with discolorations, particularly in the anterior region of the mouth. The most severe of these problems are caused by administration of tetracycline or other medicine during the period of mineralization. The usual treatment of these cases includes full crown restorations and more recently, direct or indirect veneers (porcelain or composite-resin veneers). As an alternative, the various techniques of bleaching consist the most conservative of all above treatments. For many year, their application gives effective solutions in many cases. This article describes both clinical and laboratory procedures of a new technique for bleaching discolored vital teeth. This technique uses a warming device to apply controlled heat to the bleaching solution which is placed on both labial and lingual surfaces of the teeth to be bleached. Special thermotrays are used for the placement of the solution according to the specifications of the manufacturer. This paper presents a preliminary study of the advantages and disadvantages of this bleaching method and gives an evaluation of the results from several clinical cases.