Permeability of the root canal wall and occlusion of dentinal tubules by Ag(NH3)(2)F: A comparison of combined use with pulsed Nd : YAG laser or iontophoresis

Objective: We used SEM-EDX and the Vickers hardness test to compare the pen etration and hardness of silver resulting from use of either (i) pulsed Nd: YAG laser or (ii) iontophoresis, after root canal wall shaping using the st andard method of coating with 38% Ag(NH3)(2)F solution, Summary Background Data: There have not been any reports of penetration and hardness following the application of Ag(NH3)(2)F solution together with laser or iontophores is. Methods: We used 21 extracted human single-rooted teeth randomly divide d into three groups. Group 1 was coated with Ag(NH3)(2)F, Group 2 was irrad iated with a Nd:YAG laser after coating with Ag(NH3)(2)F solution, and Grou p 3 was iontophoresised after coating. Then we observed the permeability of silver through the root canal wall using SEM-EDX, Results: The results sho w that iontophoresis after coating with Ag(NH3)(2)F solution (Group 3) resu lted in the greatest and deepest penetration of silver into the root canal wall. There was no significant difference between teeth in Groups 1 and 2, For the hardness test, the 21 teeth were tested using SEM-EDX test, 7 untre ated teeth were used as a control. The results show that Group 2 (laser tre atment) teeth were the hardest, Conclusion: We therefore propose that root canals should be treated using irradiation with an Nd:YAG laser that has be en coated with Ag(NH3)(2)F solution and that this method provides better re sults than either iontophoresis after coating, or coating alone.