Biomedical subjects
Publications and source records attributed to Norbert Velich.
Augmentation of the base of the maxillary sinus is one of the surgical procedures utilized in preparation for artificial root implantation in the maxilla. The authors intended to survey the causes of the lack of success (graft loss and implant failure) of sinus elevations with various graft materials or their combinations.
Numerous possibilities are available for the reconstruction of facial bone defects. The materials utilized to fill such defects must satisfy various requirements. One of the most important being that they must undergo transformation into autologous bone tissue in the process of remodelling. A report is given of the long-term results of augmentations performed with different bone-substitute materials in two patients. In one case, augmentation was carried out with beta-tricalcium phosphate following the removal of a fibromyxoma. In the second case, three large cystic lesions in the mandible of a patient with Gorlin-Goltz syndrome were filled with beta-tricalcium phosphate, with a mixture of beta-tricalcium phosphate and platelet concentrate, or with hydroxyapatite of algal origin respectively. The process of ossification was checked at 6-months intervals by means of clinical and radiological (orthopantomogramms and 2D and 3D computertomogramms) methods. One year after the intervention, the site of the augmentation was in all cases occupied by hard tissue of good quality. With the given imaging procedures, it was difficult to distinguish between the original bone and the region filled with bone-substitute material. The 3D computertomogramm images indicated that the contours and quality of the new bone corresponded to the physiological and anatomical conditions. The bone-substitute materials applied in these cases fully satisfied the demands of transformation into bone (remodelling).
INTRODUCTION: Before any organ transplantation, the patient undergoes a wide range of medical controls and is prepared for the surgical intervention, which lasts for several hours and imposes considerable stress on the organism; the patient is also prepared so as to be able to tolerate the subsequent lifelong need for immunosuppressive treatment. AIMS: A study was made of wether dental foci are eliminated appropriately in practice, and wether the necessary dental follow-up is performed. PATIENTS/METHOD: During a period of 10 months, 55 patients presented at the above Department for the control screening of dental foci an average of 27.5 months after organ transplantation. Physical and X-ray examinations were performed and the numbers of dental focal lesions were determined. RESULTS: The examinations revealed lesions that could be regarded as dental foci in 34.5% of the cases, and in many there were multiple (on average 2.7) focus-suspect lesions. In one case, the possibility arose of a health impairment connected with the inadequacy of the dental treatment. The last dental control examination had been made on average 22.4 months before the current focus screening. CONCLUSIONS: This study suggests the need for the uniformity of the principles of dental focus screening and dental care in patients awaiting organ transplantation and lifelong immunosuppressive treatment, for more systematic care in practice, and for the organization of regular dental controls in these patients.
Transformation of the surface of metallic titanium with titanium oxides prepared in various ways is a modern procedure. For more than 15 years, the authors have been utilizing fixing elements coated with titanium oxide ceramics, prepared by anodic oxidation and thermal treatment, for purposes of jawbone osteosynthesis. The aim of the authors' work was to assess the extent to which the titanium oxide ceramic coating influences the fate of the plates used for osteosynthesis within the human organism, in regard to the possible need for their removal. During a 5-year period, 108 of 1,396 plates coated with anodic titanium oxide had to be removed for various reasons: plate exposure (47), osteomyelitis (25), palpable swelling and tenderness (21), patient request for psychological reasons (13), or fracture of the plate (2). In none of these 108 cases was metallosis observed, which otherwise is reported relatively frequently in the vicinity of traditional titanium fixing elements, nor was any tissue damage connected with the surface of the plates. The results indicate the favorable properties of the titanium oxide ceramic surface.
Transformation of the titanium metal surface with titanium oxides produced in various ways belongs among the most up-to-date procedures. The authors as pioneers in this field (e.g. Nobel Biocare TiUnite surface), have been utilizing for more than 15 years dental root implants and fixing elements (for mandibular osteosynthesis) coated with titanium oxide ceramics, produced by anodic oxidation and thermal treatment. The aim of this work was to assess the extent to which a titanium oxide ceramic coating influences the fate of plates applied for osteosynthesis within the human body. During a 5-year period (1995-1999), 108 of 1396 titanium oxide ceramic plates had to be removed for various reasons: loosening of the plate [47], osteomyelitis [25], a palpable swelling and tenderness [21] at the request of the patient for psychological reasons (13) or breaking of the plate [2]. When these 108 plates were removed, it was not possible to detect metallosis in even a single case; nor was there any tissue damage that could be attributed to the surface of the plates, whereas the literature data indicate that such damage is relatively frequent in the environment of traditional titanium fixing elements. The present investigation confirms the favourable properties of the titanium oxide ceramic surface.
At the Department of Oral Surgery and Dentistry of Semmelweis University different studies have been carried out on the ossification, the use of various bone-substitutes and methods of bone augmentation. The aim of the present paper is to overview the literature background of an autogenous blood preparation (platelet rich plasma) with osteoinductive mechanisms applied in combination with osteoconductive bone substitutes. The role of platelet rich plasma is described in the mechanism of bone substitution, outlining the advantages of its application and the theoretical as well as the practical background of its clinical use. The routine use of platelet rich plasma has became very popular in a relatively short period of time in oral surgery though even today research and development are still very intensive in this field. According to many publications the use of autogenous blood preparations is an effective adjunctive method applied in bone substitutive therapies.
Following tooth loss it may be necessary to increase the amount of bone at the maxillary alveolar ridge into which dental implants are to be inserted. Augmentation of the maxillary sinus is performed for this purpose. It may be considered as a routine intervention, but like all surgical methods, it involves certain risks. The authors intended to assess the frequency of complications among the sinus-floor elevations that they have performed.
Following tooth loss, augmentation of the extensively atrophized alveolar ridge of the maxilla may be necessary, in order to restore the masticatory function by the replacement of teeth anchored on implants. A number of bone augmentation methods are available for the acceptance of implants. The aim of the presented report is to summarize our experience relating to the use of free monocortical bone grafts originating from the hip (spina iliaca anterior superior) for purposes of onlay-plasty.