Air abrasion process is used for cleaning casting surface of prosthetic components, and to prepare the surface of these elements for the application of veneering items. Its side effect, however, is that abrasive particles are embedded in the treated surface, which can be up to 30% of the surface and it constitutes the side effect of this procedure. Such a significant participation of foreign material can not be indifferent to the properties of the surface. Embedded particles can be the place of stress concentration causing cracking of ceramics, and may deteriorate corrosion resistance by forming corrosive microlinks. In the latter cases, it would be advisable to remove elements embedded into the surface. The simplest method is chemical etching or electrochemical one. Nevertheless, these procedures should not significantly change the parameters of the surface. Among many possible reagents only a few fulfills all the above conditions. In addition, processing should not impair corrosion resistance of titanium, which is one of the most important factors determining its use as a prosthetic restoration in the mouth. The study presented results of corrosion resistance of titanium used to make prosthetic components by means of casting method, which were subjected to chemical processing designed to remove the embedded abrasive particles. The aim of the study was to investigate whether etching with selected reagents affects the corrosion resistance of titanium castings. For etching the following reagents were used: 30% HNO3 + 3% HF + H2O, HNO3+ HF+ glycerol (1:2:3), 4% HF in H2O2, 4% HF in H2O, with a control sandblasted sample, not subjected to etching. Tests demonstrated that the etching affected corrosion properties of test samples, in each case the reduction of the corrosion potential occurred - possibly due to the removal of particles of Al2O3 from the surface and activation of the surface. None of the samples underwent pitting corrosion as a result of polarization to 9 V. Values of the polarization resistance, and potentiodynamic characteristics indicated that the best corrosion resistance exhibited the samples after etching in a mixture of 4% solution of HF in H2O2. They showed very good passivation of the surface.
Odontogenic keratocyst, until recently known as keratocystic odontogenic tumor, is a developmental, odontogenic cyst originating from a dental follicle. It is characterized by aggressive and quite fast growth, with a high tendency of recurrence (about 62% of cases). The following article presents a full description of interdisciplinary surgical-orthodontic treatment of a patient who, at the age of 12, was diagnosed with a large keratocyst of the medial region of the mandible, including unerupted teeth: 43, 44, and 45. In addition, partial retention of teeth 23 and 35 was found. Surgical treatment was performed using a two-stage method, with a 7-year follow-up period, during which impacted tooth 43 was removed, and teeth 24 and 36 were also removed. During orthodontic treatment, the acrylic plug was placed in the fenestration area, further orthodontically assisted eruption of dislocated by the cyst teeth 44 and 45, with the use of a removable orthodontic appliance and subsequently, the alignment of the upper and lower teeth with fixed appliances. After completion of orthodontic treatment, 7 years after the cyst enucleation, radiological examination was performed, which revealed a circular lesion in the projection of the roots of the lower teeth with a diameter of about 8 mm, suggesting the presence of cyst relapse. The lesion was enucleated, and the result of the histopathological examination confirmed the diagnosis.
Introduction: Hypodontia of the maxillary lateral incisors is a developmental disorder whose genetic basis has been documented scientifically. Coexistence of hypodontia and other dental anomalies may indicate the occur rence of mutations within a given gene, the expression of which may be manifested in various phenotypic com binations. Objectives: The aim of the study was to determine the frequency of cooccurrence of agenesis of the maxillary lateral incisors with other dental anomalies and skeletal disorders, based on a systematic review of the literature. Material and methods: An online database was searched using PubMed and Science Direct by entering the fol lowing keywords: maxillary lateral incisor agenesis and dental anomalies. Results: A total of 1168 results were obtained. Eighteen articles from 19712016 that met the inclusion criteria were qualified for the analysis. Hypodontia of the maxillary lateral incisors is very often accompanied by other dental or skeletal disorders. These are most often: agenesis of another permanent tooth, ectopic maxillary canine eruption, distoangulation of mandibular second premolars, reduction of the overall size of the teeth, the occur rence of a pegshaped or microdontic maxillary lateral incisor, the rectangular shape of crowns of the maxil lary central incisors, taurodontism. Skeletal class III is much more common than in the general population and the vertical relationship is also reduced. The most frequent was distal relation on the molars and canines. Conclusions: Based on information obtained from medical databases and library resources, it can be concluded that hypodontia of the maxillary lateral incisors is a condition predisposing to the cooccurrence of other disor ders: size, structure, position and quantity of remaining permanent teeth. When planning orthodontic treatment, attention should also be paid to the frequent prevalence of skeletal III in these patients and to the reduced vertical relationship.
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