Much has been published about implants with a length 10mm or over enjoying greater success than their shorter counterparts. However, Misch et al have published in an evidence based manner to cast some doubt on this. here is the abstract:
Carl E. Misch, Jennifer Steigenga, Eliane Barboza, Francine Misch-Dietsh, Louis J. Cianciola & Christopher Kazor
Implants <10 mm long in the posterior regions of partially edentulous patients have a higher failure rate in many clinical reports. The purpose of this case series study was to evaluate implant survival when a biomechanical approach was used to decrease stress to the bone-implant interface. Methods:
A retrospective evaluation of 273 consecutive posterior partially edentulous patients treated with 745 implants, 7 or 9 mm long, supporting 338 restorations over a 1- to 5-year period was reviewed from four private offices. Implant survival data were collected relative to stage I to stage II healing, stage II to prosthesis delivery, and prosthesis delivery to as long as 6 years follow-up.
A biomechanical approach to decrease stress to the posterior implants included splinting implants together with no cantilever load, restoring the patient with a mutually protected or canine guidance occlusion, and selecting an implant designed to increase bone-implant contact surface area.
Results: Of the 745 implants inserted, there were six surgical failures from stage I to stage II healing. All five failures were with a one-stage surgical approach (240 implants). There were two failures from stage II healing to prosthesis delivery. No implants failed after the 338 final implant prostheses were delivered. A 98.9% survival rate was obtained from stage I surgery to prosthetic follow-up.
Short-length implants may predictably be used to support fixed restorations in the posterior partial edentulism. Methods to decrease biomechanical stress to the bone-implant interface appear appropriate for this treatment.