Fogorvosi szemle, 2006 (99. évfolyam, 1-6. szám)

2006-04-01 / 2. szám

FOGORVOSI SZEMLE ■ 99. évf. 2. sz. 2006. DR. Z. BARÁTH, DR. M. RADNAI University of Szeged, Department of Dentistry and Oral Surgery ASSESSING THE SOLUBILITY OF DENTAL CEMENTS Beside the exact medical and dental technical work it is also essential to choose good quality cement for fixing the crowns. As the materials are being developed explosively it is difficult for the practicing doctor to select the right cement. With our research we have set in vitro tests to determine the basic pro­perties of the every day used cements such as the dissolving and the degree of degradation within a month from setting. Materials and methods: Materials used in the test were the following: Fuji Cem, Fuji Plus, Ketac Cem, Harward Phosphate Cement, and Pan­­avia 21. The different type of cements was mixed according to the instructions of the producer and then we have made cylin­drical specimens which were 3 mm thick and high. After set­ting, the test bodies were dried under infrared light and their weight was measured. After measurements the samples were put into different solutions and covered. These solutions were: distilled water, artificial saliva, mild acid (pH 6) and mild alkaline (pH 8) so­lutions, which were buffered with disodium hydrogen phos­phate and citric acid. After the 1st, 2nd, 3rd, 4th week 3-3 specimens were re­moved from the liquid, they were dried and weighed. From the change of the samples’ mass we have deter­mined whether dissolution has occurred, or not. DR. B. BENKE, DR. GY. SZABÓ, DR. GY. MARADA University of Pécs, Faculty of Medicine, Dental School THE EFFECT OF REINFORCEMENT OF COMPLETE DENTURES WITH GLASS FIBERS Purpose: The fracture of the acrylic complete dentures occurs frequently during service. The purpose of this in vitro study were to measure the impact strength of complete dentures fabricated with high-impact acrylic resin and evaluate the effect of E-glass fiber reinforcement on the impact strength. Material and methods: Preimpregnated E-glass fibers (Stick, Stick Tech LTD) were used to reinforce 10 maxillary and 10 mandibular complete denture bases with a high-impact acrylic resin (Vertex Regular, Vertex-Dental BV). 10 maxillary and 10 mandibular dentures served as a control group. All specimens were stored in water at 37 °C for 1 month before testing. The impact strengths of the dentures were measured with a falling-weight impact test. The impact strengths of both groups were compared by a repeated measures analysis. Results: The mean impact strength of reinforced dentures were higher than the mean impact strength of the control dentures. The fiber reinforcement can be easily used in both maxillary and mandibular dentures, but its high price make the dentures expensive. DR. J. BORBÉLY,1 DR. P. FEJÉRDY,1 DR. G. ACKERMANN,1 DR. I. SZILVÁSI,2 DR. CS. DOBÓ-NAGY1 1 Semmelweis University, Faculty of Dentistry, Department of Prosthodontics, Budapest;2 Semmelweis University, III Department of Internal Medicine, Department of Nuclear Medicine, Budapest VALUE OF BONE SCINTIGRAPHY IN EARLY DETECTABILITY OF ROOT CANAL TREATMENT FAILURES Introduction: Bone scintigraphy has a significant physio­logic relevance in diagnosing altered bone functions. This tool is more sensitive than radiography for the detection of osteo­blastic activity of the skeleton. While conventional radiologic techniques demonstrate bony changes when there has been an alteration of 30 to 50 percent of the bone mineral content, bone scintigraphy may be positive if there is, approximately, a 10 percent increase in the osteoblastic activity above nor­mal. The aim of this study was to compare different diagnostic modalities in root canal treatment follow up. Methodology: After formal consent 84 patients applying for detailed dental examination were enrolled into this study. These patients originally referred to perform whole body scintigraphy in order to search for bone metastasis of malignant disease. Detailed dental examination including panoramic and selected periapical radiographs were taken on the same day of radionuclid imaging. Anterior whole body bone scintigraphy was performed after intravenous injection of 700 MBq 99 tech­netium (99Tc) methylendiphosphonate (MDP) using Nucline AP gamma camera including anterior planar images of the head. Two independent dental radiologist recorded abnormal areas with focal increased tracer uptake. Results of detailed dental examination and bone scintigraphy were compared. Results: Detailed dental examination showed a total of 150 root canal filled teeth of fifty-three patients. There were 29 root canal filled teeth with no associated periapical pa­thology or marginal bone loss. In 27 root canal filled teeth periapical pathosis was seen. In 94 root canal filled teeth marginal bone loss with pocket formation was present. Focal increased activity was seen in association with 93% of pa­thological sites on anterior bone scans. Six of 29 healthy root canal filled teeth were associated with abnormal increased activity on bone scan. One year follow up resulted in the loss of two of six cases through extraction, another two showed dissolution of root canal filling material and a further two showed newly developed periapical pathosis.

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