Tooth enamel is the hardest and most highly mineralized tissue in the human body. While there have been a number of studies aimed at understanding the hardness and crack growth resistance behavior of this tissue, no study has evaluated if cracks in this tissue undergo repair. In this investigation the crack repair characteristics of young human enamel were evaluated as a function of patient gender and as a function of the distance from the Dentin Enamel Junction (DEJ). Cracks were introduced via microindentation along the prism direction and evaluated as a function of time after the indentation. Microscopic observations indicated that the repair of cracks began immediately after crack initiation and reaches saturation after approximately 48 h. During this process he crack length decreased up to 10% of the initial length, and the largest degree of reduction occurred in the deep enamel, nearest the DEJ. In addition, it was found that the degree of repair was significantly greater in the enamel of female patients.

El esmalte dental es el tejido duro mas mineralizado del cuerpo humano. En este trabajo se estudiaron las propiedades mecanicas fundamentales de este tejido para terceros molares de pacientes jovenes colombianos. Se establecieron la dureza, la tenacidad a la fractura aparente y la fragilidad del esmalte dental en funcion de la profundidad a partir de la superficie oclusal mediante tecnicas de medicion de microindentacion. Se encontro que las mediciones de dureza son altamente dependientes de la carga utilizada, hallandose que para valores de carga pequenos las huellas alcanzan a representar la dureza de un solo prisma de hidroxiapatita, mientras que para valores altos de carga las huellas abarcan un numero de prismas suficientes para estimar la dureza general del esmalte. En terminos generales los valores de las propiedades medidas son semejantes a los encontrados en estudios realizados en pacientes jovenes norteamericanos, evidenciando que estas propiedades del esmalte son independientes de las caracteristicas raciales o etnicas para pacientes jovenes, lo cual no es necesariamente extensible al comportamiento de estos tejidos en pacientes mayores.