Effect of beta-blockers on number of osteoblasts and osteoclasts in alveolar socket following tooth extraction in wistar rats

Statement of the Problem: Various researchers have suggested the use of beta 2-adrenergic receptor antagonists in prevention or treatment of bone resorption

Purpose: This study aimed to evaluate the effect of beta 2-adrenergic receptor antagonists on number of osteoclasts and osteoblasts involved in the healing of extraction socket of maxillary first molar in rats

Materials and Method: Maxillary first molars of 40 rats were extracted and divided into two groups. The test group received 0.1 mg/kg propranolol intraperitoneally daily. The controls received normal saline. At days 7, 14, 21 and 28 post-extraction, 5 rats were euthanized from each group. Maxillary bone was resected and the mean number of osteoblasts and osteoclasts in tooth socket was measured

Results: After 1 week, the number of osteoclasts in the controls was significantly higher than the test group. A significant increase in the number of osteoclasts in both groups at week 1 was observed compared to the following weeks [p< 0.05]. The number of osteoblasts in the controls at second week reached its maximum rate but stayed constant in the 3[rd] and 4[th] weeks. Osteoblasts in the test group increased similar to the controls but reached its maximum at 3[rd] week and showed a significant increase compared to the controls [p< 0.05]

Conclusion: Beta 2 adrenergic receptor antagonists decrease the number of osteoclasts and increase the number of osteoblasts during extraction socket healing

Using a silicone core to reduce the weight of maxillary obturator prosthesis

In prosthetic reconstruction of maxillectomy defects, the weight of prosthesis is usually high due to the extension of prosthesis base into the surgical defect. In order to reduce the weight, this area should be formed hollow. This study describes a modified technique for hollowing out the obturator bulb to reduce its weight. Our patient was a 56 year-old man with a completely edentulous maxilla. Due to an anaplastic carcinoma involving the palate and right alveolar ridge, a large segment of hard and soft palate and the whole right alveolar ridge were resected. After the surgery, the patient was unable to masticate or swallow and was not satisfied with the speech. The suggested treatment plan included fabrication of a complete denture along with a palatal obturator for the maxilla and a removable partial denture for the mandible. Silicone core method was used on the master cast for fabrication of the hallow bulb obturator. Maxillary hollow bulb obturator prosthesis can greatly help in restoring functional capabilities of mastication, deglutition, and speech. Silicone core method on the master cast is a simplified approach for fabrication of the hallow bulb. This method helps to achieve a smooth surface in inner aspects of the bulb

Evaluation of microleakage in pulpotomized primary molars restored with core max II: an in vitro study

Routine materials used for restoration and reconstruction of primary teeth are composite resins, glass ionomers, amalgam and stainless steel crowns. The purpose of this study was to determine the amount of microleakage in pulpotomized primary molars restored with core max II [one kind of adhesive restorative materials]. Thirty extracted primary molars were selected. After being cleaned, the teeth were pulpotomized and then covered with Zinc Phosphate as liner. The MOD cavity outline was performed with buccolingual width of 2/3 of the distance between cusp tips, and the gingival floor finished at CEJ level. Then, the teeth were divided into two equal groups of 15. Teeth in group A were restored with amalgam, whereas the others in group B were restored with Core max II. Both groups were carried to artificial mouth staying for 2 days, followed by a one-week period resting in incubator. Apices of the teeth were sealed with wax and the entire tooth surface, except for the restored zone and 1 mm beyond it, were covered with two layers of varnish and then they were floated in a special liquid paint, called Basic Fuchsin 20%. Next, roots of the teeth were cut three mm below the CEJ. After that, the teeth were mounted in epoxy resin up to 1 mm below the CEJ level. After 24 hours, all of the specimens were sectioned mesiodistally. Finally the specimens were examined with a steriomicroscope in order to determine the amount of microleakage. Using the SPSS software version 11.5 at 5% significance level, the results were analysed with Mann-Whitney U test. Paint penetration intensity in restored teeth with no microleakage was equal in group A and B. There were minor differences between these two restorative materials when microleakage penetrated to either half of gingival wall or to all of gingival wall. Paint penetration intensity in group A was equal with that of group B when microleakage penetrated in axial wall. The difference in the amount of microleakage between amalgam and Core max II was not significant [P>0.05]. According to the results of this study, since the amount of microleakage in Core max II was as low as amalgam, it can be used as an suitable alternative restorative material in pulpotomized primary molars