BACKGROUND:The high esthetic expectations from the prosthodontic restorations have directed the qualitative development of the materials towards the all-ceramic materials that are capable of replacing porcelain-fused-to-metal systems.AIM:This article reviews the literature covering the contemporary all-ceramic materials and systems with a focus on the chemical composition and materials’ properties; also it provides clinical recommendations for their use.RESULTS:The glass-matrix ceramics and polycrystalline ceramics are presented, as well as recently introduced machinable materials, all-zirconia and resin-matrix ceramics. The specific properties of zirconia, such as transformation toughening, stabilisation of the crystallographic structure, low-temperature degradation and factors affecting the zirconia’s ageing, are emphasised.CONCLUSION:The favourable properties of the resin-matrix ceramics, such as modulus of elasticity similar to dentin, shock-absorbing characteristics and high resilience and fracture resistance, are also covered in this article.

BACKGROUND:Hydrofluoric acid is a commonly used chemical in many industrial branches, but it can also be found as an ingredient in household products such as cleaning agents. Possessing high corrosive potential, HF acid causes burns and tissue necrosis, while when absorbed and distributed through the bloodstream, its extremely high toxic potential is expressed. Acute symptoms are often followed by pain, particularly in the case of skin burns, which intensiveness does not often correlate with the expressiveness of the clinical findings. Even exposure to low-concentrated solutions or gasses, or low-doses of high-concentrated acid, may provoke delayed systemic disorder which may eventually have a lethal outcome.AIM:Therefore, having information regarding the possible hazardous effects of hydrofluoric acid usage, a variety of symptoms, as well as a treatment approach, is of great importance in the case of HF exposure.METHODS:Available scientific articles published in literature databases, scientific reports and governmental recommendations from the internet websites, written in English, using the following search terms “Hydrofluoric acid, skin burns, eye injury, ingestion, inhalation, systemic toxicity, decontamination, antidote, medical treatment” have been reviewed.RESULTS:This review is useful not only for physicians but for everyone who may come in contact with a person exposed to HF acid.CONCLUSION:It highlights the mechanism of action, presents the acute and chronic symptoms, personal and general protective measures and devices that should be used, as well as decontamination procedures, immediate, antidote and hospital medical treatment.

Class II major histocompatibility complex (MHC) antigen-presenting cells are associated with the early phase of the immune response. We have studied the distribution of class II-expressing cells in developing, healthy and carious human teeth to clarify, when human pulp acquires an immunologic defense potential and how this reacts to dental caries. Antigen-expressing cells were identified immunohistochemically with the following monoclonal antibodies: HLA-DR - for dendritic cells and CD68 - for macrophages. In the pulp of unerupted developing teeth, HLA-DR-positive cells were distributed mainly in and around the odontoblast layer. A few CD68 positive cells were located more coronary around the blood vessels. In erupted teeth, HLA-DR-positive cells were located, for the most part, just beneath the odontoblast layer. CD68 positive cells were also located coronary, mainly around the blood vessels. Superficial caries lesions caused an aggregation of HLA-DR-positive cells and macrophages in the dental pulp corresponding to the lesion. These findings showed that: (1) human teeth are already equipped with an immunological defense potential prior to eruption; (2) in the initial stage of caries infection, an immuno-response mediated by class-II-expressing cells is initiated in human dental pulp (Fig. 8, Ref. 33).

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BACKGROUND:The success of prosthetic rehabilitation in patients with removable dentures depends on the achievement of the aesthetics, phonetics and most of all, proper use in the mastication process. All the patients that receive removable prostheses need a feeding education program. They must cut the food into smaller pieces, extend the length of time necessary for chewing and place the food upon both the right and left sides of the mouth at once. Bilaterally chewing with dentures will contribute to increased efficiency and denture stability during mastication. Using the anterior teeth for biting, as a result of increased pressure on the anterior ridge may lead to the anterior hyperfunction syndrome.CASE REPORT:The patient requested dental rehabilitation in our clinic for prosthetic dentistry two and a half years ago. We examined him and made therapy plan, for complete removable maxillary denture and partial mandibular denture. Besides our instructions for proper use of dentures and necessity for regular controls, his next visit was after two and a half years. He came with enlarged tuberosity and papillary hyperplasia in the pre-maxillary region. After oral surgery treatment (laser removing of hyperplastic tissue) and a healing period of four weeks, we made indirect relining on the upper denture, re-occlusion and re-articulation achieving weak contacts between the lower natural teeth and upper teeth of the complete denture. The patient was advised not to bite food with his anterior teeth, and avoid chewing very hard food which tends to imprint and displace dentures.CONCLUSION:Anterior hyperfunction syndrome with its high incidence is a disease with the need of interdisciplinary therapy approach. Fast diagnosis, thorough clinical examination using all available diagnostic tools, and choosing the right treatment is very challenging.

Introduction:A complete or partial absence of an X chromosome in the karyotype of phenotypic females has an impact on craniofacial morphology. The aim of this study was to determine the characteristics of the craniofacial complex in patients with Turner syndrome (TS), and to evaluate the influence of various karyotypes on craniofacial morphology. Materials and methods:The study population was comprised of 40 TS female patients, aged 9.2 to 18 years, and 40 healthy females, aged 9.3 to 18 years, as the control group. The TS patients were subdivided according to karyotype. All study participants were evaluated cephalometrically. An analysis of variance (ANOVA) and Tukey's multiple comparison test were used for analysis of the differences between the means in Turner subgroups and the control group.Results: In general, the girls with TS were characterized by smaller dimensions and an altered morphology of the craniofacial complex compared with the unaffected girls. The curvature of the frontal bone was significantly increased, while the diameter of the head was reduced. Both the maxilla and mandible were retrognathic, posteriorly rotated, and reduced in antero-posterior length. The cranial base was shorter and flattened. Among the different karoytypes, no significant differences were determined in the dimensions of the craniofacial complex in girls with TS. Conclusions:Our findings indicate that the karyotype has no effect on craniofacial morphology and we confirmed that a specific model of craniofacial morphology in individuals with TS is present in early childhood. is approximately one in 2,500 girls. 4 Several karyotypes responsible for the syndrome have been identified, the most common being monosomy X, found in about 50-60% of the girls. Less common are the mosaic and isochromosome for the long arm of the X chromosome.5,6 Short stature, gonadal dysgenesis, pterygium colli, cubitus valgus, and low hairline at the back of the neck are the most common features of this disease. 7The smaller size of teeth in individuals with TS 8-12 is caused by reduced enamel thickness. 13,14 Females with TS have a tendency toward distal molar occlusion, lateral crossbite, and open bite. 8,15,16 Skeletal maturity was retarded by an average of 2.2 years

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