González, Jorge EduardoJorge EduardoGonzálezPatiño Márquez, MarianelaMarianelaPatiño MárquezYepes Peña, Leonardo JulioLeonardo JulioYepes PeñaAvellaneda Dueñas, PatriciaHurtado Arango, ClaudiaPachón Rodríguez, Mónica Alejandra2026-04-132026-04-132004-01-01https://repositorio.unicoc.edu.co/handle/SII-Unicoc/1970Purpose: To compare the cemento-dentin thickness of the mesial and distal walls of the cervical, middle, and apical thirds of the mesial root of the first and second mandibular molars before and after instrumentation with K3 and ProTaper files, and the time required for biomechanical preparation. Materials and Methods: An in vitro experimental study was conducted using 32 mandibular first and second molars, whose crowns were resected, leaving mesial roots 15 millimeters long. The specimens were embedded in epoxy resin and horizontally sectioned at thirds. Pre-instrumentation stereomicrographs were taken at 65X magnification. The sections were reassembled, and the canals were instrumented with K3 and ProTaper files randomly assigned to each canal using the Crown Down technique. Post-instrumentation stereomicrographs of the canal thirds were taken. Analysis of variance was used. Results: There were significant differences in wall wear, compared by file and by third. In the buccal and lingual canals, distal wall wear was significantly greater than mesial wall wear. The apical third had significantly less average wear than the middle and cervical thirds. There was no significant difference in the time spent with the two instruments. Conclusion: Greater distal wall wear was observed in the buccal and lingual canals. There was greater mesial wall wear in the middle third with the ProTaper files. The wear achieved with the ProTaper file was significantly greater than that achieved with the K3 file. The time spent with the ProTaper and K3 files did not differ significantly.Materiales y Métodos: Estudio experimental in Vitro, utilizando 32 dientes entre primeros y segundos molares inferiores, cuyas coronas fueron respectadas, dejando raíces mesiales de una longitud de 15 milímetros. Los especímenes fueron embebidos en resina epóxica y seccionados horizontalmente en tercios. Se tomaron fotografías con estereomicroscopio a 65X preinstrumentación, se reensamblaron las secciones y se instrumentaron los conductos con limas K3 y ProTaper asignadas aleatoriamente a cada uno con técnica Crown Down, se tomaron fotografías de los tercios con el estereomicroscopio postinstrumentación. Se utilizó análisis de Varianza. Resultados: Hubo diferencias significativas entre el desgaste de las paredes, comparado por lima y por tercio. En el conducto vestibular y lingual el desgaste de la pared distal fue significativamente mayor que en la pared mesial. El tercio apical tuvo un promedio de desgaste significativamente menor que los tercios medio y cervical. No hubo diferencia significativa en el tiempo empleado con los 2 instrumentos. Conclusión: Se observó mayor desgaste de la pared distal en los conductos vestibular y lingual. Hubo mayor desgaste en la pared mesial en el tercio medio con las limas ProTaper El desgaste realizado con la lima ProTaper fue significativamente mayor que el realizado con la lima K3. El tiempo utilizado con la lima ProTaper y K3 no tuvo diferencias significativas.71 pp.application/pdfesEspesorParedesPreparaciónK39ProTaperInvestigación de campotext::thesis::bachelor thesisTEN 056ThicknessWallsPreparationK39ProTaperopenAccess