Odontostomatologike proodos最新文献

The purpose of this in vitro investigation was to examine the degree of microleakage in class II, MOD, posterior composite resin restorations, in the distal wall of which a layer of 1,5 mm of ceramometallic cement was condensed. Conventional MOD cavities were prepared using 330 and 56 tungsten carbide burs in 20 premolars extracted for orthodontic reasons. In the first group (10 specimens) the gingival floor was located in the enamel, above the cementoenamel junction and in the second group the gingival floor was located below the CEJ. In the mesial box, cervically, a layer of 1,5 mm of ceramometallic cement (Ketac Silver) was condensed and etched with orthophosphoric acid 37%, the cavity was filled with posterior composite resin (Heliomolar, Vivadent) and 24 hours later the specimens were polished using Sof-Lex discs and thermocycled between 4 degrees C and 60 degrees C for 50 cycles of 2 minutes each. The specimens were immersed for 2 hours in 2% basic fuchsin solution, washed, cleaned with acetate solution and split in two halves longitudinally in a mesiodistal direction, using a hard tissue microtome. From the detection of the degree of dye penetration we conclude that: a) In the cervical walls located in cementum, where cermet cement was condensed, minimal dye penetration was detected b) In the opposite side, where the composite resin existed on dentin-cementum, the dye penetration is more severe c) Dye penetration in cavities located in the enamel, is moderate in the areas where cermet cement existed d) No dye was detected in the interface between cermet cement and posterior composite, in most specimens.

This study refers to the part that is played by the musculature system, the nervous system, the saliva and the mucosa to the retention and support of the complete denture. At the same time, it also refers to these systems from anatomic, histological and physiological point of view, in relation however, to the requirements of the removable dentures.

This paper is a review of the cements of the poly-acrylic acid. The composition and the mechanism of setting of these cements are examined as well as their clinical application.

In order to examine the relationship existing between soft tissue configuration and the underlying skeletodental framework, patients presenting severe and representative syndromes of the head and neck were studied. Grouping of these patients in three groups according to the similarities of the skeletal pattern and/or the etiology of the syndrome, provided a basis for evaluation, comparison and contradistinction of the configuration of the hard and soft tissues, in a material where genetic predetermination is dominant. By cephalometric analysis, superimposition and plotting of the soft tissues on an abstraction and relative magnification basis, the following conclusions could be formulated: a) There is a specificity in the soft tissue configuration of the face of patients with specific syndromes and, this specificity, seems to be independent of the underlying skeletodental elements in the area of the nose and the upper lip. b) A genetic predetermination of the soft tissue morphology can be deduced because, in patients with specific syndromes, the same characteristics accompany constantly the same chromosomal or gene mutations. c) Further studies along these lines might throw more light on the role of genetics in soft tissue configuration and function.

In this paper we present a typical case of GARRE's chronic osteomyelitis. The patient was a 11 years old boy who has been examined for an asymptomatic hard swelling of the mandible on the right side. The X-ray examination with panoramic film revealed radiolucency apically of No 46 and 85 molars and in the occlusal film it was evident the "onion-peel" appearance of newly formed bone. A diagnosis of GARRE's chronic osteomyelitis was made and the teeth were extracted. Two months later after the extraction there wasn't swelling on the mandible.

Ultrasonography is one of the newest diagnostic methods for the visualization of pathologic conditions of the soft tissues of the human body. This method has an indication also for the localization and diagnosis of benign and malignant lesions in the head and neck area. This study was done in order to inform the dentist about this new and completely safe diagnostic method and also, to present the sonographic image of the physiologic structures in the head and neck area. Ultrasonography was performed in 20 persons who had a free past medical history and no sign of disease in the head and neck area. Attention was made in order to include in the study persons of all ages, of different weight and of both sexes in order to include any possible variation of the anatomic order. The examination was done with Aloka S.S.D.-280 L.S. ultrasound camera and the probe applied was the US - 5 MHz and connected with the Echo-Coupler ECM-1, which was used for the first time in Greece. Ultrasonographic examination was made in the submandibular, sublingual, parotid and neck region and the physiologic structures, which were studied, included the thyroid, the sternocleidomastoid muscle, the carotid artery and jugular vein, muscles of the submandibular area, the sublingual, submandibular and parotid salivary glands and the masseter muscle.

In this review the biology of granulocytes (PMNL, eosinophils, basophils) is analyzed, with reference to the differentiation and maturation stages, and their function. The phenomenon of phagocytosis and the secretory function are described in detail as well as the different chemical systems which participate in the microbiocidal activity of these cells. Finally, emphasis tis given to the biochemistry of the synthesized and secreted enzymes contained in their granules.

A totally new product, by the name Scotchbond 2 (3M Co) appeared recently in the field of bonding agents. Grace to its improved formula, the manufacturers claim that both the bond strength and the sealing ability of the material, render it trustful for use in both anterior and posterior composite resin restorations. The purpose of this in vitro investigation was to determine the microleakage pattern around slot type cavities, restored with posterior composite resin (P-50, 3M Co) using two different generations of bonding agents. Two types of cavities were prepared in sound premolars extracted for orthodontic reasons. In the first group (10 teeth) the cervical wall was located in the enamel, above the cementoenamel junction and in the second group (10 teeth) the cervical wall was located below the CEJ. The enamel surrounding the cavity margins was etched using 37% orthophosphoric acid gel, rinsed and dried and the bonding agents were applied and cured according to the manufacturer s instructions. The posterior composite was condensed and light-cured incrementally, in three horizontal layers. The samples were thermocycled for 200 cycles of 4 minutes each between 4.37 and 60 degrees centigrade, covered with fingernail varnish and sticky wax and immersed in 0.5% basic fuchsin dye for 12 hours. The specimens were split in two halves longitudinally in a mesiodistal direction in a hard tissues microtome and the degree of dye penetration was evaluated using an optical microscope. According to the results obtained we come to the conclusions that: 1. The use of Scotchbond 2 minimized but did not eliminate the microleakage around posterior composite resin restorations, in both types of cavities.(ABSTRACT TRUNCATED AT 250 WORDS)

The creep and recovery of microspecimens of glass-ionomer cements was studied using a tortional creep apparatus. The purpose was to investigate viscoelastic behavior in a low stress that might result from normal chewing forces. Small stress (2,048 MPa), below the composite resin's proportional limit, was maintained for 3 h and after the stress was released. Recovery was followed for 50 h. The measurements were made on specimens: aged 24 h stored dry at 21 degrees C, aged 24 h stored in distilled water at 21 degrees C, aged 24 h stored in distilled water at 37 degrees C, aged 1 week stored in distilled water at 37 degrees C. The glass-ionomer cements exhibited linear viscoelastic behavior at low deformations. The materials did not recover their original shape after 50 h after the stress was removed. The least amount of creep and permanent deformation exhibited the specimens aged for 1 week in distilled water at 37 degrees C. The influence of dehydration was apparent on specimens measured dry at 21 degrees C. They exhibited the greatest amount of creep and permanent deformation.

This paper is a review of the current literature concerning osteoradionecrosis. The pathogenetic mechanism, etiology, predisposing factors and frequency of the disease are discussed, and the relation between extractions before or after irradiation and the onset of the disease are stated. Diagnosis of the disease is analysed, together with the various methods of treatment and prevention. Finally, emphasis is given to the role of the dentist in the management and prevention of the disease.