Do longer implants improve clinical outcome in immediate loading?

It is generally believed that longer implants (length >13 mm) have higher success rates than standard implants (length = 13mm). Few reports focus on long implants and none specifically address the clinical outcome of immediate loading (IL) of longer implants. This retrospective study was performed to compare the clinical outcomes of long and standard length implants. A total of 244 standard and 536 long implants were inserted and immediately loaded. The mean follow-up was 3 years. Only 4 of 780 implants (99.5%) were lost, and these 4 were all 13 mm long. No or reduced marginal bone loss was taken as an additional indicator of success to evaluate the effect of several factors on clinical outcome. Only 4 of the 244 13-mm-long implants were lost (98%), but this was statistically different from the survival rate of longer implants. Poor quality bone was related to increased marginal bone loss and thus a worse outcome in both groups. IL standard length implants have a high survival rate, but it is statistically worse than that of IL longer implants. Standard or longer implants are reliable devices for insertion in poor quality bone, although slightly higher bone resorption is to be expected.