Type And Material of Fixed Prosthodontic Appliances in Patients Living in the Region of Metković

The aim of this study was to evaluate the type and the aesthetic material in relation to age, gender, level of education, employment, socio-economic status and frequency of visits to the dentist. The examination was performed on 212 patients who had a fixed prosthodontic appliance for more than a year (55% males and 45% females, age 18-80 yrs.). The following conclusions were made: 1. The older patients and retired patients had significantly more bridges than crowns (p0.05). Patients who visit their dentist regularly have significantly more crowns than bridges than patients who visit their dentist irregularly or when in pain (p0.05). 2. Almost all fixed prosthodontic appliances older than 10 years were made of porcelain (98%), while acrylic veneer crowns were more frequent in appliances older than 10 or 15 years (p0.05). Patients older than 60 years had more acrylic material compared to younger patients. While patients younger than 39 years had almost exclusively ceramic appliances (p<0.01). Less educated patients had more acrylic veneer appliances. Employed patients had significantly more ceramic appliances than retired patients

Screening of Fixed Prosthodontic Dentures after Five Years of Use in Relation to Material and Construction

The aim of this study was to screen patients with fixed prosthodontic appliances that were in oral cavity for a period of 5 years or more and to assess clinically and radiologically root caries, gingival recession, pocket formation, alveolar ridge resorption, as well as gingival (GI) and plaque index (PI). The aim also was to find out the differences between materials and constructions, between abutment and non-abutment teeth, and to find out the need for replacement. A total of 260 patients and their orthopantomograms were examined, with a total of 2,265 teeth, 610 being bridge abutments and 246 being crowns. The most frequent were metal+ acrylic veneer crowns or bridges. Root caries was found under the abutments in 10–20%; however abutments with ceramic crowns had the lowest percentage of caries (p<0.01). Alveolar ridge resorption, pocket formation deeper than 3 mm and gingival recession of various degree was found in 50% of the cases, again with the lowest percentage of ceramic-fused-to-metal appliances (p<0.01). Pocket depth was registered in significantly higher percentage in metal-acrylic veneer appliances compared to natural teeth (p<0.01), while there was no significant difference between metal-ceramic appliances and natural teeth (p>0.05). Although the worst findings were recorded for metal-+acrylic veneer crowns for PI, no significant difference existed between crowns of different material or non-abutment teeth (p>0.05). There was statistically significant difference between abutments with metal + acrylic veneer crowns, full metal crowns, metal ceramic crowns and non-abutments for GI scores. Higher percentage of scores 0 and 1 was recorded for metal ceramic crowns and non-abutments and significantly higher percentage of scores 2 and 3 was recorded for metal + acrylic veneer crowns and full metallic crowns. Almost 50% of metal-ceramic abutments had no pathologic findings. Almost 30% of the patients needed replacement, or even some abutments to be extracted and therefore a new prosthodontic appliance

Consequences of a covariant Description of Heavy Ion Reactions at intermediate Energies

Heavy ion collisions at intermediate energies are studied by using a new RQMD code, which is a covariant generalization of the QMD approach. We show that this new implementation is able to produce the same results in the nonrelativistic limit (i.e. 50MeV/nucl.) as the non-covariant QMD. Such a comparison is not available in the literature. At higher energies (i.e. 1.5 GeV/nucl. and 2 GeV/nucl.) RQMD and QMD give different results in respect to the time evolution of the phase space, for example for the directed transverse flow. These differences show that consequences of a covariant description of heavy ion reactions within the framework of RQMD are existing even at intermediate energies.Comment: LaTex-file, 28 pages, 8 figures (available upon request), accepted for publication in Physical Review

Analysis of Occlusal Contacts in Different Types of Prosthodontic Appliances, Eichner Classifications, Presence RCP-ICP Slide and the Type of Occlusion

The aim of the study was to determine the number and the type of the occlusal contacts (strong, weak) with respect to the type of the prosthodontic appliance (fixed, removable, combined fixed-removable) and with respect to the Eichner classification in patients with their appliances being in a good function for a long time. The aim of the study was also to determine the number and the type of the occlusal contacts (strong, weak) with respect to the type of occlusion (canine guided, group function or balanced) and the presence of the RCP-ICP slide. A total of 440 patients with different types of prosthodontic appliances were examined for the antagonistic occlusal contacts using occlusal strips of 11 m and 50 m. The average number of occlusal contacts was 10.5 for the upper and 10.46 for the lower posterior teeth, approximately 5 on each side of the tooth arch. The results of the study suggest that the biggest number of occlusal contacts were recorded for the small span fixed appliances (2 on average), the greater span fixed and fixed-removable prosthodontic appliances exhibited 1.6 occlusal contacts, and the removable complete denture exhibited 1.2 contact per the tooth in the posterior region. The number of the hard occlusal contacts was significantly greater in fixed and fixedremovable prosthodontic appliances in comparison with the complete dentures (p < 0.05), while there was no significant difference between the prosthodontic appliances for the weak occlusal contacts (p > 0.05). The overall number of the occlusal contacts, as well as the number of the hard occlusal contacts was significantly greater in the Eichner class I cases (p < 0.05) in comparison with the Eichner classes II and III. The number of the weak occlusal contacts showed no significant differences with respect to the Eichner classification (p > 0.05). There was no significant difference in the number of occlusal contacts between the appliances with RCP-ICP slide and where ICP and RCP corresponded (p > 0.05)

METROLOGICAL SUPPORT OF DOSIMETRY GAMMA-RAY WITH ENERGY TO 10 MEV FOR RADIATION PROTECTION DEVICES

The field of high-energy gamma-ray for the calibration of radiation protection devices can be obtained by capturing thermal neutrons from titanium target (to 7 MeV) and nickel target (to 10 MeV). The aim of this work was to determine the metrological characteristics of capture gamma-ray fields from titanium target and nickel target obtained at the AT140 Neutron Calibration Facility to provide dosimetry up to 10 MeV.We have chosen energy intervals in which we can calibrate dosimetry devices taking into account the accompanying generation of gamma-ray neutrons by the fast neutron source 238PuBe, the capture radiation of collimator materials and capture radiation from targets.We measured air kerma rate with the aid of the reference AT5350 dosimeter with the ionization chamber TM32002. Using the Monte-Carlo simulation, we obtained the energy distribution of the air kerma rate for targets. We determined the geometric dimensions of the uniform field and the interval of operating distances of the facility.We investigated the metrological characteristics of capture gamma-ray fields from titanium target and nickel target obtained at the AT140 Neutron Calibration Facility for dosimetric radiation protection devices. We showed that in such fields it is possible to calibrate dosimetry devices in the extended energy range up to 10 MeV

Quasigroups, Asymptotic Symmetries and Conservation Laws in General Relativity

A new quasigroup approach to conservation laws in general relativity is applied to study asymptotically flat at future null infinity spacetime. The infinite-parametric Newman-Unti group of asymptotic symmetries is reduced to the Poincar\'e quasigroup and the Noether charge associated with any element of the Poincar\'e quasialgebra is defined. The integral conserved quantities of energy-momentum and angular momentum are linear on generators of Poincar\'e quasigroup, free of the supertranslation ambiguity, posess the flux and identically equal to zero in Minkowski spacetime.Comment: RevTeX4, 5 page

Energy Distribution of a Stationary Beam of Light

Aguirregabiria et al showed that Einstein, Landau and Lifshitz, Papapetrou, and Weinberg energy-momentum complexes coincide for all Kerr-Schild metric. Bringely used their general expression of the Kerr-Schild class and found energy and momentum densities for the Bonnor metric. We obtain these results without using Aguirregabiria et al results and verify that Bringley's results are correct. This also supports Aguirregabiria et al results as well as Cooperstock hypothesis. Further, we obtain the energy distribution of the space-time under consideration.Comment: Latex, no figures [Admin note: substantial overlap with gr-qc/9910015 and hep-th/0308070

Effects of deposit-feeding bivalve (Macomona liliana) density on intertidal sediment stability

Effects of macrofaunal feeding and bioturbation on intertidal sediment stability (u*crit) were investigated by manipulating density (0-3 x ambient) of the facultative deposit-feeding wedge shell (Macomona liliana) on the Tuapiro sandflat in Tauranga Harbour, New Zealand. Sediment stability increased up to 200% with decreasing M. liliana density and this was correlated with greater sediment microalgal biomass and mucilage content. The change in stability occurred despite homogeneity of grain size amongst experimental treatments, highlighting the importance of macrofaunal-microbial relationships in determining estuarine sediment erodibility