Evaluation of machining accuracy and consistency of selected implants, standard abutments, and laboratory analogs.

Thirteen implants having external hexagonal extensions were evaluated for machining accuracy and consistency. A composite score was derived to evaluate overall manufacturing accuracy and consistency of the implants evaluated in this study. A technique to determine the rotational freedom between implant and abutment is described, and the coronal hexagonal matings of selected implants and abutments is evaluated and reported. Crossover use and combinations of products from different manufacturers was also evaluated for rotational freedom. Two nonexternal hexagonal extension implant configurations were measured for rotational movement as contrasting and comparative values.