text: Pins and posts--why, when and how.
  Pins and posts retain restorations and protect remaining tooth structure; they are indispensable to conservative operative dentistry. Effective utilization of these pin-post systems requires application of proper biomechanical principles for each clinical situation. No one design will suffice in every case. A parallel, serrated, cemented device in a precise matched channel is the ideal combination of characteristics. When tooth morphology or heavy function require increased retention, it may be achieved by increasing pin-post length, diameter, and number or by utilizing the resilience of dentin. However, the dentist must be aware that the price for more retention is the increasing risk of damaged tooth structure. Optimal long range results will be obtained by utilizing pins and posts in conjunction with veneer types of restorations. When used in this manner, they will save many teeth each year and simultaneously reduce the rate of failures.