[Allergies to dental materials and effectiveness of treatment in the north-eastern region of Hungary]. / Fogászati anyagokkal szemben kialakuló allergiás megbetegedések és ellátásuk hatékonyságának vizsgálata az észak-alföldi régióban.

The recognition and treatment of allergy is a great challenge for all fields of medicine. The high prevalence of allergic reactions to dental materials and the related financial burden of their treatment make investigation of this disease very important. Our investigation was carried out on patients assigned to our outpatient department for dental allergy test between 1996 and 1998. We determined the distribution of gender and age among the allergic patients in the examined population. We also studied the prevalence of allergic reactions to different dental allergens and the distribution of dental allergens. In a follow-up study we determined the proportion of those patients, who were retreated in conformity with the results of epicutan tests and we followed up the positive effects of these treatments. We have found that dental allergy occurred five times more frequently in women (84%) than in men (16%) and the most affected age group was between 20 to 39 and 40-49 years (31%). Seventy-five percent of the patients suffered from a combination of metal and polymer allergy. The most frequent metal allergen was TEGDMA (triethylene glycol dimethacrylate) (49.7%). The suggested treatment plan was carried out in 63% of the allergic patients. The applied treatment was successful in 48% of these cases. We experienced that 48% of these patients got rid of their earlier signs and symptoms.

[Synthesis of nanoparticles for dental drug delivery systems]. / Fogászatban alkalmazható hatóanyagok leadására alkalmas nanorészecskék szintézise.

Modern drug delivery systems are designed for targeted controlled slow drug release. Up to now polymer based hydrogels have been applied in dentistry, which systems can affect the rate of the release due to their structure. Recently, intensive research for other methods is performed all over the world in order to improve the effectiveness of delivery systems. Nanotechnology is one of the most dynamically developing disciplines and is a powerful tool to increase the bioavailability of drugs. The aim of this work is to synthesise biocompatible nanoparticles by free radical initiated copolymerization of the monomers, 2-hydroxyethyl methacrylate (HEMA) and polyethyleneglycol dimethacrylate (PEGDMA) in aqueous solution, which can support the formation of nanoparticles that can be used as a drug delivery system for dental applications. The polymer-based nanoparticles were prepared via micellar polymerisation, which resulted a well dispersible white powder material. The size of particles was determined by Dynamic Laser Light Scattering (DLS) and Scanning Electron Microscopy (SEM). The size of particles is in range of 50-180 nm, measured by SEM. These values are commensurable with the results obtained by DLS experiments, where two size ranges were observed, as 40 +/- 15 nm and 180 +/- 30 nm. The nanoparticles are suitable for incorporation into a hydrogel matrix and to design new drug delivery devices for dental applications.

[Orthodontic treatment possibilities of allergic patients]. / Allergiás betegek fogszabályozó kezelésének lehetoségei. Esetismertetés.

During the past two decades the incidence of allergies against dental materials has been rising. The most common allergens are nickel, mercury, benzoxyl-peroxide, formaldehyde, MMA, HEMA, EGDMA and TEGDMA. Contact allergy develops in predisposed individuals as a consequence of environmental exposures to allergens. Although the relatively high frequency of contact allergies in children is well documented, its importance during orthodontic treatments is still often underestimated. The most common metal to cause dental allergic reactions is nickel. Nickel-containing metal alloys, such as nickel-titanium, are widely used in orthodontics because of their favorable physical properties. Coated wires (epoxi coating, teflon, etc.) are not only more aesthetic, but can play a role in the orthodontic treatment of patients with nickel allergy. In our case report we present two patients with nickel allergy, and their treatment with alternative orthodontic appliances. During the orthodontic treatment our patients did not have any objective or subjective allergy-related symptoms.

[Synthesis and compression strength of hydrogels]. / Hidrogélek szintézise és nyomási szilárdságuk vizsgálata.

The purpose of the present investigation was the synthesis of crosslinked polymers and the assay of the effect of the monomer ratio to the compression values. Hydrogels were made by free radical photoinitiation from 2-hydroxyethyl metachrylate (HEMA) monomer, poly(ethylene glycol) dimethacrylate (PEG-DMA) crosslinker and sodium anthraquinone-2-sulphonate initiatior. The concentration of HEMA and PEG-DMA was 30 %, and their ratio was varied to obtain gels with different crosslinking density. It was found, that increasing the amount of the crosslinker in the gels, the force of the deformation increased, however the elasticity decreased. The lowest difference was found between the molar ratio of 50% HEMA: 50% PEG-DMA and the 75% HEMA: 25% PEG-DMA gels. Compression strength was strongly influenced on the ratio of the crosslinking agent. The smallest compression strength was found at the lowest amount of PEG-DMA (90% HEMA: 10% PEG-DMA) (0.0475 MPa +/- 0.0117) and the highest value was found at the highest amount of the PEG-DMA (10% HEMA: 90% PEG-DMA) (0.1366 MPa +/- 0.0546). The values of the compression strength at gels with similar composition was not significantly different. On the base of the present investigations the elasticity of the materials could be calculated from the ratio of monomers. It could be an important parameter in the further applications of the gels as a local delivery system in the parodontology.

[Prevalence of hypodontia in 4-18-year-old children in Department of Paediatric Dentistry, Faculty of Dentistry, University of Debrecen from 1999 to 2003]. / A csírahiányok elofordulási gyakoriságának vizsgalata a DEOEC FOK Gyermekfogászatán 1999 és 2003 között.

Hypodontia is one of the most common human dental anomalies. Its management is often complicated. This survey was carried out to study the prevalence, localisation and combination of congenital aplasia in Department of Paediatric Dentistry, Faculty of Dentistry, University of Debrecen. The study group consisted of 669 children, 283 boys and 386 girls, aged 4-18 years. Orthopantomograms and clinical examinations were used for the retrospective study. The prevalence of hypodontia was found to be 7.76 percent, excluding the third molars. Most of the congenitally absent teeth were the upper lateral incisors and the lower second premolars. The most frequent combinations were the 12-22 and the 35-45 ones. We found that our data were very similar to the different international results.