Radiosensitizers, radioprotectors, and radiation mitigators.

Radiotherapy is regarded as one of the most important therapeutic modality for the treatment of malignant lesions. This field is undergoing rapid advancements in the recent times. With the use of radiosensitizers and radioprotective agents, the course of radiotherapy has improved the sensitization of tumor cells and protection of normal cells, respectively. The aim of this paper was to critically review and analyze the available compounds used as radiosensitizers, radioprotectors, and radiation mitigators. For reviewing, the author used the electronic search for the keywords 'Radiosensitizers', 'Radioprotectors', 'Radiation mitigators' on PubMed for inclusion of previously published articles and further search of reference papers on individual radiosensitizing and radioprotecting agents was done. Radiosensitizers are agents that sensitize the tumor cells to radiation. These compounds apparently promote fixation of the free radicals produced by radiation damage at the molecular level. The mechanism of action is similar to the oxygen effect, in which biochemical reactions in the damaged molecules prevent repair of the cellular radiation damage. Free radicals such as OH + are captured by the electron affinity of the radiosensitizers, rendering the molecules incapable of repair. Radioprotectors are compounds that are designed to reduce the damage in normal tissues caused by radiation. These compounds are often antioxidants and must be present before or at the time of radiation for effectiveness. Other agents, termed mitigators, may be used to minimize toxicity even after radiation has been delivered. This article tries to discuss the various aspects of radiosensitizers, radioprotectors, and radiation mitigators including the newer agents.

Central mucoepidermoid carcinoma of the maxilla with unusual ground glass appearance and calcifications: A case report

Mucoepidermoid carcinomas (MECs) arising within the jaws as primary central bony lesions are termed central MECs. Central MECs are extremely rare, comprising 2-3% of all mucoepidermoid carcinomas. We herein report a rare case of central MEC of the maxilla in a 52-year-old male whose plain radiographs showed a "ground glass" pattern and computed tomographic images, a hypodense mass with numerous calcifications. To the best of our knowledge, this is the first report of central MEC showing a "ground glass" appearance.

Adenoid cystic carcinoma of sublingual salivary gland obstructing the submandibular salivary gland duct.

Sublingual salivary gland malignancies are extremely rare and account for only 0.3-1% of all epithelial salivary gland tumors. Here, we report a case of adenoid cystic carcinoma (ACC) of the sublingual salivary gland that presented as a swelling in the right anterior floor of the mouth obstructing the submandibular duct. Sublingual salivary gland ACC obstructing the submandibular duct is rare and only three cases have been reported in the literature until date. We discuss the different patterns of ACC seen during the pathologic investigations and its radiologic features.

An Assessment of Antibacterial Activity of Four Endodontic Sealers on Enterococcus faecalis by a Direct Contact Test: An In Vitro Study.

Aim. To evaluate the antibacterial activity of four endodontic sealers on Enterococcus faecalis by a direct contact test. Material and Methods. Enterococcus faecalis was used as a test organism. Direct contact test which is based on measuring the effect of close contact between test bacteria and tested material on the kinetics of bacterial growth was performed to overcome the disadvantages of agar diffusion test. The sealers tested were zinc oxide eugenol-based sealer, glass-ionomer-based sealer, polydimethyl-siloxane-based sealer, and urethane dimethacrylate resin-based sealer. Data was collected by recording the optical density with the help of a spectrophotometer. Results. The sealers exhibited different inhibitory effects. The results obtained were subjected to statistical analysis by Kruskal Wallis analysis of variance and Dunn's multiple comparison test. Group comparison showed very highly significant difference between the groups. Conclusion. Zinc oxide eugenol-based sealer was the most effective and urethane dimethacrylate resin-based sealer was the least effective against Enterococcus faecalis, whereas glass-ionomer-based and polydimethyl-siloxane-based sealers were effective only for a short period. Inhibition of the bacterial growth is related to the direct contact of the microorganism with the sealer.

Odontogenic myxoma of the mandible.

Odontogenic myxomas are benign but locally aggressive neoplasms found almost exclusively in the jaws and arise only occasionally in other bones. We present a rare case of odontogenic myxoma occurring in the mandible of a 19-year-old male patient with a brief review of clinical and radiological features, and diagnostic and operative dilemmas in managing the same.