Poster 28, Language: English
Chemical analysis of the quality of the In-Ceram-system presumes a complete understanding and knowledge about its microstructure and its chemical and macroscopic composition. As far as science is concerned, the knowledge about ionic exchange in the borderline of compound materials (such as glass - infiltered aluminium oxide and ceramics) is mandatory. This knowledge could be the base for further results in the research about the persistency, the process of erosion and the wearing-out, as well as the mechanisms of fracture of the In-Ceram-system in the oral cavity.
Keywords: In-Ceram, ceramic
Poster 29, Language: German
30% of all children show a class II occlusion. This occlusion anomaly is normally treated with activator. The remodeling operations in the muscles of mastication are still insufficiently solved. Pigs show a chewing pattern similar to human. 10-weeks old pigs were used for the present treatment. Animals were divided into 2 groups of 6 each. Treatment (with build-ups) was realized during a period of 4 weeks. Genetic changes in the musculature were registered by Northern blotting and the polymerase chain reaction (PCR). Two isoforms of the Myosin Heavy Chain of the different muscle fiber types I and II (slow twitch and fast twitch) were examined in order to demonstrate stress of muscles. Differences in mRNA- content were proved in all muscles of mastication. Treatment conditional adaptation of one fiber type into the other was realized by PCR. By this the adaptation of the muscles of mastication after sagittal advancement of the lower jaw was genetically proved in the animal experiment for the first time.
Keywords: training effects, Myosin, muscle fiber types
Poster 30, Language: German
Salivary antibacterial components in the salivary sediment of children. This investigation was aimed to determine antibacterial salivary factors in the salivary sediment; those factors were to be compared to the same factors of the saliva. - Unstimulated and stimulated whole saliva was collected by 59 children (24 girls / 35 boys; age: 10-11 years). After centrifugation the salivary sediment was resuspended in 0,5 M NaCl and incubated at 4°C for 2 hours. Thereafter, it was centrifuged again. Both supernatants were examined for their contents of lysozyme, peroxidase, thiocyanate, secretory immunoglobulin A (S-IgA), µ-amylase, and total protein. For the eluted portions, the quantities per gram sediment as well as their hypothetical concentrations in the starting volume of saliva were calculated. Both were then compared to the salivary concentrations or activities, respectively, by means of the paired t-test, with p£0.05 as the level of significance. - In each case, all examined salivary components could be eluted from the sediment. The quantities per gram sediment were much higher than the quantities per ml of saliva. Thus, an enrichment must have taken place on the surfaces of the corpuscular components of the saliva. The eluted quantities correspond to 30-50% of the salivary concentration concerning peroxidase, 75-90% concerning lysozyme, 5-15% concerning thiocyanate, 27-40% concerning s-IgA and 9-15% concerning total protein. Therefore, the adsorbed antibacterial sali-vary factors of the salivary sediment should be taken into account, when the salivary composition is discussed in connection to oral diseases.
Keywords: saliva, salivary sediment, peroxidase, lysozyme, secretory immunoglobulin A, protein, Thiocyanate, alpha-amylase
Poster 31, Language: English
In urethra reconstruction, the forming of a new urethra from an free oral mucosa graft is an established surgical technique. The oral mucosa is taken simultaneously during the urethra reconstruction procedure. Depending on the size of graft required, the intraoral wound is closed primarily or left to secondary healing. The latter limits this technique leading to scars strictures which have a negative impact on the intraoral soft tissue condition. Therefore, in a pilot study with 12 patients tissue engineered mucosa was tested for covering intraoral defects in order to avoid drawbacks mentioned above. To tissue engineer mucosa grafts a biopsy from the hard palate, diameter size 2 to 4 mm, was taken approximately 4 weeks before the operation. In addition, 30 ml autogenous serum was produced out of a venous whole blood sample. The primary cultures were incubated in Dulbecco's modified Eagles Medium, Nutrient Factor F 12 containing the usual additives as well as autogenous serum. After a period of 3 weeks subcultivation was performed to engineer mucosa transplants consisting of several layers of keratinocytes on a support foil. After thorough intraoperative blood coagulation, the cultured mucosa graft on the carrier foil was applied on the wound surface and fixed by single sutures. Additionally, the cultured mucosa graft was covered by an intraoral dressing for 8-10 days which was also fixed onto the wound surface by single suture loops. Primary intraoral wound closure with tissue engineered mucosa is possible to cover defect sizes up to 11.0 x 4.0 cm. This new method provides better perspectives for both urethra reconstruction and reconstruction of intraoral tissue defects. Intraoral scars strictures are diminished. This is of special interest for the reconstruction of the functional unit oral cavity including soft tissue and cosmetic conditions (e.g. in case of prosthetic rehabilitation). In comparison to primary wound closure with local tissue this technique reduces postoperative pain and allows faster rehabilitation of the patients basing on a better wound healing process. Furthermore, better mobility of intraoral soft tissue structures is achieved.
Keywords: tissue engineering, oral reconstruction, hypospadia
Poster 32, Language: English
Computer assisted surgery (CAS) has not been integrated yet in the surgical routine of reconstructive cranio-maxillofacial surgery. Modified software makes navigation systems applicable for the requirements in reconstructive surgery i.e. preoperative planning, virtual reconstruction, intraoperative navigation and postoperative control including restaging procedures in oncology cases. We report on 25 cases of orbital reconstruction among a total of 54 cases that were planned and operated using the STN-navigation system (Stryker-Leibinger). Using CAS the surgeon has the chance to virtually design the important reconstructive surgical steps prior to the operation; stereolithographic models can be completely replaced. During surgery the planned contours can be as well navigated as the position of the eye-bulb. In unilateral deformities mirroring of the unaffected side allows for ideal virtual reconstruction. Meanwhile the indications for using CAS on a routine base are extended from primary and secondary orbital corrections to skullbase tumors, in which the pretherapeutically definded safety margins are navigated during the operation, corrections of craniostenoses, complex bimaxillary orthognathic cases, minimal invasive biopsies at the skullbase, transethmoidal optic nerve decompression and insertion of zygomatic implants.
Keywords: computer assisted surgery, frameless stereotaxy, maxillofacial surgery, reconstructive surgery
Poster 33, Language: English
In industrial technology surface treatment by micro-blasting and micro-peening are increasingly used as they reach a high degree of surface refinement and strengthening. These methods are of interest in dental technology, especially for the treatment of Titanium castings. The aim of the present investigation is the experimental evaluation of a micro-dry-blasting-method (Gruber and Stübinger, Linz/Austria), using an abrasive and a spherical blasting medium, separate and in combination. Cast samples (20x10x2 mm) of Titanium (grade 1) were used for the experiments. Their initial surface conditions were
- casted and cleaned in an ultrasonic bath
- wett grinded on SiC-paper, grit size 220, 600, 1200.
The finished surfaces were characterised by light- and scanning electron microscopy (SEM) and analysed profile-graphically (RZD, Sm). Surface near parts of the finished samples were light microscopically investigated on metallographic transverse sections. From the results the following conclusions can be drawn:
1. The abrasive micro-blasting of Titanium castings removes surface near layers and shows an levelling effect. Microstructural defects are extensively diminished.
2. Abrasive micro-blasting of surface ground before (SiC220) shows the same result, but in lower degree. Abrasive micro-blasting of fine-ground samples is of no use.
3. The micro-peening technique in combination with the foregoing abrasive microblasting or grinding effects a further levelling and compaction of the surface. The average distances of the peaks are increased.
The investigated methods enable a rationalisation of surface finishing and an improvement of surface quality of Titanium castings. Their combination with usual milling and polishing methods of dental laboratories was tested and can be recommended.
Keywords: finishing of Titanium, shoot peening, abrasive micro-blasting, surface levelling and compaction, metallographic structure, roughness
Poster 34, Language: English
Sjögren's syndrome, the unknown etiologic factors, is an autoimmune process that results in rheumatoid arthritis and causes dry eyes (keratoconjunctivitis sicca) and dry mouth (xerostomia) because of the destruction of lacrimal and salivary gland. It is divided clinically two type which one is called primary Sjögren's syndrome (SS-1) represented by xerostomia and keratoconjunctivitis sicca, and seconder Sjögren's syndrome (SS-2) represented systemic connective tissue disease in addition to dry eyes and mouth. The peak age of onse is 50 years, and 90% of cases occur in women. The chief oral complaint is xerostomia, causes the eating, speaking lubrication, taste difficulties. Also there are a greater risk for dental caries, periodantal disease, and oral candidiasis. In this poster, we present a 23-year-old women had diagnosed Sjögren's syndrome,unknown type of syndrome. As a result of the biochemical and radyologic investigaments seconder Sjögren's syndrome, xerostomia, keratoconjunctivitis sicca and rheumatoid arthritis was diagnosed in ours clinic. The restoration of all caries teeth which were involved the endodontic treatment of lower santral teeth, the composit restoration with screw following the filling root canals and prothetic rehabilitation, the elevation of vertical dimention and fixed prothetic restoration were made and gave a flour tablets and oral hygein. Patient has been followed-up.
Keywords: sjögren's syndrome, prothetic rehabilitation, autoimmune disease
Poster 35, Language: German
The risk of caries and periodontal disease in case of crowding and overjet has been analysed in an epidemiologic cross sectional study based on clinical findings and cast analysis.
125 patients were devided into different groups: the first group aged between 18 and 34 years, 31 male and 32 female; the second group aged 35 years and older, 31 male and 31 female.
The clinical examination was based on the WHO-OHS methods. The modified analyses of segmented arch systems by LUNDSTRÖM was used to acquire the amout of crowding, the registration of the amout of overjet based on an analysis by KLINK-HECKMANN.
The study figured out the correlations between age, the amount of crowding and overjet and caries, dental fractures, abrasion, gingivitis and periodontal disease. A high risk for dental destruction was found by patients with crowding of more than 5 mm and overjet of more than 5 mm.
Keywords: crowding in the lower labial segment, overjet, caries, dental fracture, periodontal disease, bleeding, pocketing, recession, abrasion