[Survival and success rate of dental implants treated with high intensity laser]. / Lézerrel felületkezelt dentális implantátumok túlélési és sikerességi rátájának vizsgálata.

Clinical and radiological evaluations were conducted in patients with high energy Nd : glass laser-treated dental implants. These patients underwent dental implantation surgery between 1997 and 2006. Strict success criteria were used for the examination and analysis of implants. Based on clinical and radiological evaluation, success and survival rates of laser surface treated dental implants were similar to those of sandblasted, acid-etched surface implants frequently reported in the literature. Specific surface morphology and high degree of purity of laser surface treated dental implants ensure excellent osseointegration and a good clinical performance also on the long-term.

[Possibilities of clinical testing of osseointegration in oral implants]. / Fogászati implantátumok csontintegrációjának klinikai vizsgálatával szerzett tapasztalataink.

The osseointegration of oral implants is of utmost importance as far as the success of implant prosthetics is concerned. In clinical practice osseointegration can only be tested indirectly. The loading of implants is usually linked to osseointegration as a condition. Under some circumstances implants can be loaded before osseointegration is completed. The present study reviews the various methods of testing osseointegration and the conditions of immediate loading. In the present study the changes in the stability of 59 implants restored with screw-retained superstructures and partly immediately loaded, were observed over a period of several years, with the help of the Periotest method. Based on the statistical evaluation of the results, a significant correlation was found between implant insertion torque and primary stability. A difference was found between the stability of implants in the upper and lower jaws. A typical curve in the temporal changes of implant stability was described.

[A biomechanical study of Uniplant SP temporary dental implants: loading under laboratory conditions]. / Uniplant SP fogászati ideiglenes implantátumok laboratóriumi terheléses vizsgálata.

The mechanical strength parameters of Uniplant SP temporary implants were investigated. In clinical practice temporary implants are used to provide the patient with a fixed temporary restoration. Temporary implants are one-part implants small in diameter, and by design they have excellent primary stability. The temporary fixtures are usually placed simultaneously with the final implants. They positioned between the final implants. Due to their good stability they can immediately be loaded. They are usually expected to function till the final implants are ready for loading and when no longer needed, the temporary implants are removed. The abutment that carries the prosthetic components is manufactured in one piece with the implant, connected to it with a narrower neck portion. This neck part might easily fracture in the first instance when the abutment is bent to make abutments parallel in order to fabricate the temporary prosthetic device and in a second instance when temporary implants are removed. In the present study the mechanical properties of the cervical part were studied in a custom-designed device. Based on the results of the loading studies recommendations were made to modify the current shape of the implant. With minimal modification of the implant design and lengthening the implant neck risk of fracture can be significantly reduced.

[The proximal tibia. A possible donor site in preprosthetic surgery]. / A tibia proximalis epiphysise mint lehetséges autológ csontvételi hely.

With the development of oral implantology the augmentation of the alveolar process and the maxillary sinus has become a more and more frequent procedure. Even though a vast array of bone replacement materials is available commercially, they all just have an osteoconductive effect. By now it has become clear that the 'gold standard' of bone grafts is autologous bone that is both osteoconductive and osteoinductive. Autologous bone is mostly harvested from intraoral sources. If a larger quantity of spongious bone is needed, it is from extraoral sites, mainly from the iliac crest. In some countries the use of the proximal epiphysis of the tibia for bone harvesting is more widespread. In our Department a sinus lift was performed with spongious bone harvested from the tibia in 14 patients within 9 months. A mean 20 cc of bone can be harvested from one site, which is sufficient for the augmentation of both sinus floors in all cases. The patients tolerated surgery well, healing was without complications. Patients were mobilised immediately after surgery. Patients tolerated the postoperative period significantly better than after bone harvesting from the iliac crest.

[Changes in the indications for oral surgical implants based on statistical analysis]. / Az implantációs sebészeti beavatkozások indikációs területének változása a statisztikai vizsgálatok tükrében.

Journals, books and lectures on oral implantology are concerned less and less with the various fields of indication and their changes. The reason for this is in part that from a surgical point of view we consider the lack of contraindication as the indication of dental implant placement, while from a prosthetic point of view implant supported prosthetic work can be done in any prosthetic situation. Despite of this it is an interesting question, how the ratios of the various fields of indication have changed in view of the age groups and genders in Hungary in the past twenty years. In the present study a part of the patients reporting to the outpatient clinic of the Department of Oral and Maxillofacial Surgery and Dentistry of Semmelweis University for dental implant placement in the past 22 years were analyzed using statistical methods. Various age groups, genders and types of implants were compared in view of the indication of placement. The results were compared to data published in international literature.

[A biomechanical study of the mechanical stress transmission of dental implants using finite element analysis. Part II. Experiments]. / Fogászati implantátumok mechanikai feszültség-atadásának biomechanikai vizsgálata végeselemes analízissel. II. Rész vizsgálatok.

In the first part of this two-part study the possible uses of finite element analysis in studying the stress transmission of dental implants were reviewed. In the present second part our own experiments are presented. In the first series the effect of the geometric parameters and load types on mechanical stresses arising around cylindrical implants in bone were studied with 2D and 3D finite element analysis. In the second series the stress transmissions of various implant geometries were compared and an attempt was made to determine the optimal implant shape from the point of view of stress transmission.

[A biomechanical study of the mechanical stress transmission of dental implants using finite element analysis. Review of literature. Part I]. / Fogászati implantátumok mechanikai feszültségátadásának biomechanikai vizsgálata végeselemes analizissel. Irodalmi áttekintés I. rész.

Finite Element Analysis (FEA) is a computerised investigative method that is capable of determining the mechanical stress arising in various objects and their environment as a result of forces effecting the system by using a mathematical model. The method is most often used for purposes of technical, engineering design, but is very useful for medical purposes-the static and functional investigation of the skeletal and motor system of the human body-as well. The transmission of mechanical stress between the implant and bone depends on a number of factors, and its description is quite complicated. A model has to be created to perform a FEA, the geometric data of the implant, the mechanical properties of the bone and the parameters of the bone-implant interface have to be determined, a so-called finite element network has to be created. Valuable data can be obtained by changing the individual elements of the system. The study of dental implants makes it possible to better investigate biomechanical conditions and thus the further perfection of implant methods. In the first part of the present two-part publication authors review the possibilities of use of the finite element analysis in examining the stress transmission of dental implants. In the second part of the publication their own studies will be presented.

[The effect of the surface morphology of Ti-implants on the proliferation activity of fibroblasts and osteoblasts]. / A titán-implantátumok felületi mikromorfológiájának hatása a fibro- es oszteoblaszt sejtek proliferációs aktivitására.

It is known that surface morphology greatly influences the osseointegration of dental implants. The goal of the experiments conducted by the authors was to study in vitro the effect of various surface modifications on the activity of bone and connective tissue cells. In the experiments they introduced NIH3T3 fibroblast and MCH3T3 osteoblast cells were cultured the surface of ten titanium disks with various morphology in 24-multiwell plates. The cells were let grow on the surface of the disks for two days in a culture medium. One group of the disks underwent scanning electronmicroscopy and the changes in the number and form of cells on the surfaces were studied under various magnifications. From the surface of the second group the cells were lysed and were counted in a Bürker's chamber. After counting the cells they were lysed in a lysis buffer and their protein concentrations were measured with the help of a spectrophotometer. The authors found that only a morphological study of the cells is possible under SEM, they could not detect a quantitative difference in the number or activity of the cells. Upon counting the cells and determining their protein concentration the best result were yielded by the surface roughened by aluminium oxide. In growing fibroblasts the titanium oxide treated surfaces provided good results, while in the case of the osteoblasts the laser treated disks were more successful.