RESUMEN
El objetivo fue evaluar la eficacia de remoción del material de obturación y el tiempo empleado para la desobturación con tres métodos diferentes, en modelos réplica. Se utilizaron 24 modelos réplica de premolares inferiores instrumentados con sistema Protaper Gold hasta F4, irrigación NaOCl 2,5% y ED-TAC 17%. Obturación termoplastizada sistema Fast Pack Pro. La muestra (n=24) se dividió aleatoriamen-te en tres grupos experimentales (n=8) sometidos a distintos métodos de desobturación. Grupo 1: fresas Gates Glidden II/III y limas Hedstroem. Grupo 2: lima Medium sistema Wave One Gold y punta ultrasóni-ca Ultra X, (Eighteeth). Grupo 3: lima Rotate 35/04 y punta ultrasónica R1 Clearsonic, (Helse). Se midió el tiempo de desobturación. Las piezas se radiogra-fiaron con radiovisiógrafo digital RVG 5200 (Cares-tream), y fueron procesadas con software Image-J. Al analizar cantidad de material de obturación rema-nente, la prueba de Kruskal-Wallis (p<0,05), mostró diferencias estadísticamente significativas entre grupos 2 y 3. Grupo 1 no mostró diferencias signifi-cativas con los otros dos (p>0,05). Al analizar tiempo de desobturación, el test de Kruskal-Wallis no deter-minó diferencias significativas entre grupos 1 y 2 (p>0,05), el grupo 3 tuvo diferencias estadísticamen-te significativas con los grupos 1 y 2 (p<0,05). En con-clusión, ninguno de los sistemas de desobturación evaluados logró eliminar la totalidad del material de obturación. El que combinó limas rotatorias con punta ultrasónica de retratamiento fue el que mos-tró mayor efectividad de remoción y demandó menor tiempo de trabajo (AU)
Objective: to evaluate the effectiveness of obturation material removal and the time that the procedure took, when performing the retreatment with three different methods, in replica models of mandibular premolars. Materials and methods: 24 replica models of lower premolars instrumented with Protaper Gold system up to F4, 2.5% NaOCl irrigation and 17% ED-TAC were used. Thermoplastized sealing with Fast Pack Pro system. The sample (n=24) was randomly divided in three experimental groups (n=8) subjected to different unsealing methods. Group 1: Gates Glid-den burs II and III and Hedstroem files. Group 2: Wave One Gold Medium file system and Ultra X ultra-sonic tip, (Eighteeth). Group 3: Rotate 35/04 file and R1 Clearsonic ultrasonic tip (Helse). Unsealing time was measured. The samples were radiographed with a digital radiovisiograph RVG 5200 (Carestream), and processed with Image-J software. When analyzing the amount of remaining filling material, Kruskal-Wallis test showed statistically significant differences be-tween groups 2 and 3 (p<0,05). Group 1 did not show significant differences with the other two (p>0,05). When analyzing unsealing time, Kruskal-Wallis test determined that there were no significant differ-ences between groups 1 and 2 (p>0,05), but group 3 had statistically significant differences with the other two (p<0.05). None of the unsealing systems evalu-ated managed to eliminate all of the sealing material. The group that combined rotary files with ultrasonic retreatment tip showed the greatest removal effec-tiveness and required less work time (AU)
Asunto(s)
Retratamiento/métodos , Modelos Dentales , Ultrasonido/métodos , Efectividad , Interpretación Estadística de Datos , Instrumentos DentalesRESUMEN
Asian sea bass, Lates calcarifer (Bloch), exhibited strong immune responses against a single injection of the formalin-inactivated red-spotted grouper nervous necrosis virus (RGNNV), a betanodavirus originally isolated in Japan. Fish produced neutralizing antibodies at high titre levels from days 10 (mean titre 1:480) to 116 (1:1280), with the highest titre at day 60 post-vaccination (1:4480). When fish were challenged with the homologous RGNNV at day 54 post-vaccination, there were no mortalities in both the vaccinated and unvaccinated control fish. However, a rapid clearance of the virus was observed in the brains and kidneys of vaccinated fish, followed by a significant increase in neutralizing-antibody titres. Furthermore, the vaccine-induced antibodies potently neutralized Philippine betanodavirus isolates (RGNNV) in a cross-neutralization assay. The present results indicate the potential of the formalin-inactivated RGNNV vaccine against viral nervous necrosis (VNN) of Asian seabass.