Comparative study of the retentive strengths of dowels of three different diameters in combination with one or two different-sized threaded pins

Vented parallel-sided, serrated posts cemented into matching precision channels provide excellent retentive strength; however, they do not offer significant resistance to rotational forces. This article explores the effectiveness of using supplementary pins to compensate for this deficiency. A standardized method was used to place combinations of parallel-sided posts and screw-type pins in prepared root canals of extracted human teeth. Standardized composite resin cores were made for the posts. Results indicate that the dentist must take note of the amount of dentin available for pin placement and, with reference to the provided graphs, determine the ideal size and number of pin(s) to be inserted.