Length of the Implant Used
The length of the implant to be used is dictated by the available bone height. The success rate is proportional to the implant length and the quality and the quantity of the available bone. The rate of implant failure can be expected to rise proportionately as the depth of the bone diminishes to less than 10 mm. However, certain implant designs which claim higher surface area (either due to sintered Ti particles) are known to work in shorter lengths. It is a thumb rule to use the longest length possible within anatomical limits as the use of a shorter implant when a longer could be used results in less bone implant surface area, higher stress concentration and thus the associated failures. The crown-implant body ratio affects the appearance of the final prosthesis along with the moment of force on the implant and the crestal surrounding bone. The greater the crown-implant ratio, the greater will be the amount of force with any lateral force. Therefore, the maximum implant length possible should be used for the greatest stability of the overlyingprosthesis.