Scripta Scientifica Medicinae Dentalis

4

Authors: Radosveta Andreeva, Ani Beltcheva

In spite of all the methods of prevention, there still are untreated or improperly treated caries and it’s followed by complications. This often leads to premature loss of teeth. The premature loss of the deciduous teeth depends on different factors such as oral hygiene, traumas, complicated caries. The aim of this study is to compare the OHI-S between children with premature loss and those without premature loss of deciduous teeth. Subject of the monitoring of the clinical research were 140 children between ages 6 and 9. The clinical group consisted of 90 children with prematurely extracted teeth, divided into three groups. The control group consisted of 50 children with intact denture. The oral hygiene status was examined and registered by the Greene-Vermillion index-simplified. There was a statistically significant difference in the OHI-S between the control group (1.86±0.05) and the clinical groups (1.90±0.08 and 2.01±0.05). The children with premature extraction of the primary teeth had higher OHI-S compared to the control group (children without premature extraction of teeth). The third group of children, with prematurely extracted temporary teeth and severe orthodontic deformation, have the highest OHI-S. These results demonstrate the connection between OHI, the orthodontic deformations and the need for prevention.

4

Authors: Tihomir Georgiev, Radosveta Andreeva

The premature extraction of primary teeth of children could be done both under local or under general anesthesia. Тhe method of choice depends on different factors. Dental treatment under GA is an effective way to provide necessary dental care to children with special needs, medically-compromised, cognitively immature, highly anxious. The aim of this study is to compare the average age and the average DMFT index of the children with premature extraction of primary teeth treated under local and under general anesthesia. Subject of monitoring of the research were 60 children. The clinical group consists of 30 children with teeth for premature extraction under general anesthesia and the control group consists of 30 children for premature extraction under local anesthesia. The dental status was examined and registered by the DMFT index. The age of the children was filled out in special registration cards. There was a statistically significant difference in the age and the DMFT index between the first group (4.67±0.26 average age) and second group(4.67±0.26 average age ). The DMFT index for the first (clinical) group is 7.18±0.66 and – 5.17±0.33 for the second (control) group. The results show the connection between the carious activity and the need of prevention in younger children.

6

Authors: Elitsa Djongova, Tihomir Georgiev, Karen Dzhabalyan, Radosveta Andreeva, Mariana Dimova-Gabrovska

INTRODUCTION: Bony projections on the inner surface of the maxillary sinus are divided into two main groups: exostoses, which are rounded bone structures, and septa, defined as having a pointed end. Bony septa are common anatomical structures and can lead to complications during sinus augmentation procedures. MATERIALS AND METHODS: The study reports a clinical case of a vertical partial basal bony septum, where upon elevation of the sinus membrane, its perforation was observed (size >5 mm). RESULTS: The present study proposes a method of treatment of perforated sinus membranes.The post-surgical period was uneventful. The bone grafting material remained compact in the sinus augmentation site. CONCLUSIONS: The proposed method for the management of perforated sinus membranes can be applied in surgical procedures for perforations > 5 mm in size.

7

Authors: Tsanka Dikova, Dzhendo Dzhendov, Iveta Katreva, Diana Pavlova, Maksim Simov, Svetlana Angelova, Metodi Abadzhiev,Tsvetan Tonchev

The purpose of the present paper is to establish experimentally the possibilities of the 3D printer Rapidshape D30 for the manufacturing of standard cubic samples from different types of monomers and to evaluate their geometrical accuracy and roughness. Standard cubic samples with dimensions 5mm х 5mm х 5mm were printed from all the materials, given by the producer, in two ways of dimensional orientation according to the base – horizontally and inclined at 45о. They were manufactured with 3D printer Rapidshape D30, working on a stereolithography principle with LED light. It was established that: ❖ The samples, made of NextDent Surgical Guide, have the highest dimensional accuracy and the lowest deviation interval in both ways of placement. This polymer is characterized with the highest thickness of the polymerization layer – 0.100 mm, but it is transparent, thus ensuring the entire polymerization throughout the depth of the whole layer. NextDent C+B, intended for manufacturing of temporary crowns and bridges, occupies a middle position in comparison to the other 6 materials. ❖ Nearly in all the materials the surface roughness of the cube with horizontal placement is lower than that of the cube printed inclined (average values of Ra 0.46-2.69µm and Ra 1.74-2.77, respectively). ❖ In 3D printing the surface roughness depends on the thickness of the polymerization layer and the inclination to the printing direction. The thicker the polymerization layer and the larger the slope, the higher the surface roughness.

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Authors: Tihomir Georgiev, Karen Dzhabalyan, Radosveta Andreeva, Krasimira Prodanova

INTRODUCTION: Pneumatization of the maxillary sinus can be triggered throughout a patient‘s life. Prior to any sinus floor augmentation procedure, it is imperative to conduct a linear and volumetric assessment of the maxillary sinus. MATERIALS AND METHODS: The CBCT scans in this randomized retrospective study were selected from 120 patients (50 men and 70 women) to analyze the maxillary sinus dimensions both linearly and volumetrically. RESULTS: The volume of the maxillary sinus was significantly increased in the male patients. Statistically significant differences in the volume of the maxillary sinuses were not observed in dentate or edentulous patients. CONCLUSIONS: CBCT imaging for surgical interventions of the maxillary sinus to assess its volume and size has proven to be an indispensable diagnostic tool.

11

Authors: Roussi Minev, Ekaterin Minev

The paper describes the basics of the 3D printing technologies for rapid prototyping (RP). It shows the benefits of their utilization in product design and manufacturing of conventional parts and items with medical and other application. The most mature RP principles are presented and compared. Some trends in developing new 3D printers and corresponding materials for micro/nano and biological applications are described. Some modern budget platforms are suggested for technology users. The paper also provides a summary of the main quality issues in the layering technologies as well as methodologies for studying the process capabilities, accuracy and maturity.