The present study was designed to evaluate Propolis collected from five different areas (Shaqulawa, Aski Kalak, Haji Omran, Duhok and Koisinjaque) in Kurdistan region/ Iraq as a new resinous sealer in root canal obturation. The chemical constituents, visual examination and its physical prosperities according to American national standard institute /American Dental Association specification No. 57 for endodontic sealing materials were investigated. Moreover, the new material was implanted in vivo to investigate its effect on soft tissue healing. Dye penetration was also performed to evaluate its effect on apical microleakage.
Outcome of chemical analyses on the ethanolic extract of the Propolis samples revealed the presence of flavonoids and benzophenone in all the samples.
Regarding the physical properties, the melting point was for the Propolis samples measured depending on American Standard for Testing Materials D-87 test of bee wax. Depending on the results of this test and visual examination, it was decided to use Propolis sample that was collected from Shaqulawa area.
The radiopacity test demonstrates that raw Propolis was radiolucent and acceptable radiopacity according to the specification No 57 (not less than 3mm aluminum). Accordingly, it was decided to mix with Propolis 20% barium sulfate, eventually adequate radiopacity was obtained. Concerning the solubility and film thickness of the tested material, the samples were within the desirable limits for acceptable endodontic material proposed by American Dental Association.
The biocompatibility of Propolis was also studied. Eighteen albino rats, of six week old were used to evaluate subcutaneous biocompatibility of the Propolis sample compared with zinc oxide eugenol sealer as a control. The animals were divided into three groups, six rats to be sacrificed at three intervals: three days, seven days and twenty one days after implantation. The histopathological study expressed that Propolis sample was biocompatible with the surrounding tissues.
For detection of the apical dye penetration of the Propolis, sample as endodontic sealer, one hundred and twelve freshly extracted human single-rooted teeth were collected and divided into eight groups of fourteen teeth each. In the first group the teeth were obturated with Thermafil obturators coated with Propolis only without sealer. While obturation of the second group was done with Soft Core obturators coated with Propolis only with out sealer. The third and fourth groups were obturated with Thermafil and Soft Core obturators respectively using Propolis as a sealer after dilution with ethanol. In group five and six, obturation was done with Thermafil and Soft Core obturator using Propolis as a sealer after dilution with eugenol. For the last groups, obturation was performed by using Thermafil and Soft Core obturators respectively with zinc oxide eugenol based sealer, these groups were considered as the control of this study. The obtained results from dye penetration test showed that using Propolis as sealer after dilution with ethanol produce better sealing ability than the other groups.
In conclusion, it is suggested according to the obtained results in this study that the tested Propolis sample had desirable properties as sealer that fit the requirements of American national standard institute /American Dental Association specification No. 57 for endodontic sealing materials.