Each sample had to comply with the following requirements: teeth had to be caries-free, present 20 to 22 mm crown to root length, and had to have been extracted due to periodontal problems or orthodontic treatments.
Cada muestra debía cubrir los siguientes requisitos: no presentar caries, tener una longitud entre 20 y 22 mm de la corona a la raíz y haber sido extraídos por problemas periodontales o por tratamientos ortodóncicos.