O objetivo deste experimento foi avaliar as variações da permeabilidade dentinária do sistema endodôntico produzidas pelo protocolo de irrigação intracanal: ácido cítrico a 15%, EDTA-T a 17%, MTAD, Smear Clear e NaCl 0,9% e a influência de diferentes lasers: Diodo, Er:YAG, Nd:YAG, utilizando para isso o radioisótopo Tecnécio-99m (99m Tc) (PARTE a) e o polietilenoglicol 400 (PEG 400) marcado 99m Tc (PARTE b). Foram selecionadas 150 raízes palatinas de molares superiores, divididas em 5 grupos, com 10mL/amostra para realizar a irrigação. Inicialmente analisou-se 10 raízes de cada grupo, introduzindo-se 5?L de 99m Tc no canal radicular, sendo então imersos em NaCl 0,9%, com exceção da superfície da entrada do canal para realizar a contagem da quantidade de radioisótopo dissociado para o meio externo (salina), sendo que se realizou os mesmos procedimentos com a introdução de PEG marcado (5?ci) no canal radicular. Posteriormente, cada um dos grupos experimentais foram subdivididos em outros 3 para irradiação com os diferentes lasers: Diodo (1,5W, modo contínuo, fibra de 300?m de diâmetro); Er:YAG [100mJ (42mJ output),1W, 10Hz, fibra com 0,375?m]; Nd:YAG (100mJ, 1,5Hz, 15W, fibra com 300?m). Repetindo-se os mesmos procedimentos primeiramente com 99m Tc livre e posteriormente o PEG400 marcado com 99m Tc para a realização para a contagem do radioisótopo dissociado na solução salina. Os dados obtidos foram tabulados e a analisados estatisticamente pelo teste Tukey com 95% de confiança. Pôde-se concluir que a irradiação com laser Nd:YAG + irrigação com ácido cítrico, ou com EDTA-T apresentaram os melhores índices de permeabilidade, enquanto que a irrigação com NaCl 0,9% e o MTAD apresentaram os piores índices pe permeabilidade independente da aplicação do laser. O ácido cítrico e o EDTA-T apresentaram os melhores resultados na ausência de irradiação e também no grupo irradiado pelo Er:YAG. E ao irradiar com Diodo a irrigação com EDTA-T apresentou maior permeabilidade. / Assess the variation of root canal dentin permeability produced by intracanal irrigation protocol: 15% citric acid, 17% EDTA-T, MTAD,Smear Clear and 0,9% NaCl and irradiation with different lasers: Diodo, Er:YAG, Nd:YAG using radioisotope technetium-99m (99mTc ) (PART a) and polietileneglycol 400 (PEG) marked with 99mTc (PART b) was the aim of this study. Hundred fifty palatin roots of molar were selected and divided in 5 groups to carry out the irrigation with 10 mL/sample of the solutions. Ten roots of each group were analyzed, introducing 5?L of the 99mTc dissolved in distilled water, with aproximatly 5?L in the root canal and imersed in 0,9% NaCl to carry out the count of amount of 99mTc dissociated to the external enviroment and after introducing 5?L of PEG marked with 99m Tc (5mci). Later, the groups were (PART b) divided to other 3 to irradiate with the folowing parameters: Diodo (1,5W, continuous, 300?m filament); Er:YAG [100mJ (42mJ output),1W, 10Hz, 0,375?m fiber]; Nd:YAG (100mJ, 1,5Hz, 15W, 300?m fiber). The same procedures were repeted to count and the obteined datas were analyzed statistically by the tukey test with 95% reliance. It was concluded that Nd:YAG laser + irrigation with citric acid or EDTA-T have presented the best scores of permeability, while the NaCl and the MTAD presented the worst scores independent of the laser irradiation. The citric acid and the EDTA-T have presented the best results in absence of laser and also, in the group irradiated by Er:YAG laser. Additionaly, if we irradiate with Diode, the EDTA-T group presented higher permeability.

O objetivo deste experimento foi avaliar as variações da permeabilidade dentinária do sistema endodôntico produzidas pelo protocolo de irrigação intracanal: ácido cítrico a 15%, EDTA-T a 17%, MTAD, Smear Clear e NaCl 0,9% e a influência de diferentes lasers: Diodo, Er:YAG, Nd:YAG, utilizando para isso o radioisótopo Tecnécio-99m (99m Tc) (PARTE a) e o polietilenoglicol 400 (PEG 400) marcado 99m Tc (PARTE b). Foram selecionadas 150 raízes palatinas de molares superiores, divididas em 5 grupos, com 10mL/amostra para realizar a irrigação. Inicialmente analisou-se 10 raízes de cada grupo, introduzindo-se 5?L de 99m Tc no canal radicular, sendo então imersos em NaCl 0,9%, com exceção da superfície da entrada do canal para realizar a contagem da quantidade de radioisótopo dissociado para o meio externo (salina), sendo que se realizou os mesmos procedimentos com a introdução de PEG marcado (5?ci) no canal radicular. Posteriormente, cada um dos grupos experimentais foram subdivididos em outros 3 para irradiação com os diferentes lasers: Diodo (1,5W, modo contínuo, fibra de 300?m de diâmetro); Er:YAG [100mJ (42mJ output),1W, 10Hz, fibra com 0,375?m]; Nd:YAG (100mJ, 1,5Hz, 15W, fibra com 300?m). Repetindo-se os mesmos procedimentos primeiramente com 99m Tc livre e posteriormente o PEG400 marcado com 99m Tc para a realização para a contagem do radioisótopo dissociado na solução salina. Os dados obtidos foram tabulados e a analisados estatisticamente pelo teste Tukey com 95% de confiança. Pôde-se concluir que a irradiação com laser Nd:YAG + irrigação com ácido cítrico, ou com EDTA-T apresentaram os melhores índices de permeabilidade, enquanto que a irrigação com NaCl 0,9% e o MTAD apresentaram os piores índices pe permeabilidade independente da aplicação do laser. O ácido cítrico e o EDTA-T apresentaram os melhores resultados na ausência de irradiação e também no grupo irradiado pelo Er:YAG. E ao irradiar com Diodo a irrigação com EDTA-T apresentou maior permeabilidade. / Assess the variation of root canal dentin permeability produced by intracanal irrigation protocol: 15% citric acid, 17% EDTA-T, MTAD,Smear Clear and 0,9% NaCl and irradiation with different lasers: Diodo, Er:YAG, Nd:YAG using radioisotope technetium-99m (99mTc ) (PART a) and polietileneglycol 400 (PEG) marked with 99mTc (PART b) was the aim of this study. Hundred fifty palatin roots of molar were selected and divided in 5 groups to carry out the irrigation with 10 mL/sample of the solutions. Ten roots of each group were analyzed, introducing 5?L of the 99mTc dissolved in distilled water, with aproximatly 5?L in the root canal and imersed in 0,9% NaCl to carry out the count of amount of 99mTc dissociated to the external enviroment and after introducing 5?L of PEG marked with 99m Tc (5mci). Later, the groups were (PART b) divided to other 3 to irradiate with the folowing parameters: Diodo (1,5W, continuous, 300?m filament); Er:YAG [100mJ (42mJ output),1W, 10Hz, 0,375?m fiber]; Nd:YAG (100mJ, 1,5Hz, 15W, 300?m fiber). The same procedures were repeted to count and the obteined datas were analyzed statistically by the tukey test with 95% reliance. It was concluded that Nd:YAG laser + irrigation with citric acid or EDTA-T have presented the best scores of permeability, while the NaCl and the MTAD presented the worst scores independent of the laser irradiation. The citric acid and the EDTA-T have presented the best results in absence of laser and also, in the group irradiated by Er:YAG laser. Additionaly, if we irradiate with Diode, the EDTA-T group presented higher permeability.

Indiana University-Purdue University Indianapolis (IUPUI) / Introduction: During root canal treatment (RCT), an opening is made through the crown of the tooth to access and to disinfect the root canal system (RCS). Traditional endodontic access (TEA) may sacrifice tooth structure and weaken the tooth. Cone beam computed tomography (CBCT) provides information about the exact location of the root canals. This information can be used for the design of a canal-directed endodontic access (CDEA). It may also be used for the 3D printing of an acrylic endodontic stent that could help to create a conservative CDEA. Objective: 1) Evaluate the ability of the Dolphin 3D imaging software to assist in creating a CDEA; 2) Compare tooth structure loss in a CDEA to that in a TEA by measuring the volume of remaining tooth structure, surface area of the access opening at the occlusal, and remaining dentin thickness at the CEJ. Materials and Methods: Thirty extracted human mandibular premolars were used. Teeth with large, wide canals were excluded. CBCT images will be taken for all teeth using Kodak 9000. Fifteen teeth were randomly assigned to the TEA group and 15 teeth were assigned to the CDEA group. The CDEA path was mapped using Dolphin 3D imaging software. Acrylic access stents were designed using Rhino 3D software and printed using a 3D printer. The teeth were accessed through the corresponding stents. The 15 teeth that are part of the traditional access group were accessed without a stent. A CBCT scan was taken post-access for all 30 teeth. Wilcoxon Rank Sum Tests were performed to compare the following outcomes for the two groups: the volume of remaining tooth structure, the surface area of the access opening at the occlusal, and remaining dentin thickness at the CEJ. Results: The remaining dentin thickness (percent loss) was not significantly larger for TEA than for CDEA. The surface area (post-treatment) was significantly larger for TEA than for CDEA, and volume (percent loss) was significantly larger for TEA than for CDEA. Conclusion: The use of the CBCT and Dolphin 3D imaging provided an accurate and more conservative CDEA with the guide of an acrylic stent.