Selection of the implant transgingival height for optimal biomechanical properties: a three-dimensional finite element analysis

We evaluated the effects of the transgingival height of an implant on the maximum equivalent stress in jaw bones and the maximum displacement in implant-abutment complex by a finite element method. The transgingival height ranged from 1.0–4.0 mm. Under axial load, the maximum equivalent stress in the cortical bone could be reduced by up to 4.7%, and under a buccolingual load, the maximum equivalent stresses in the cortical and the cancellous bones could be reduced by 17.3% and 18.5%, respectively. The maximum displacement of the implant-abutment complex could be reduced by 4.1% and 48.9% under axial and buccolingual loads, respectively. When the transgingival height was in the range of 1.7–2.8 mm, there was minimum stress in the jaw bones and minimum displacement in the implant-abutment complex. Data indicated that transgingival height played a more important part in protecting a dental implant under a buccolingual load than under an axial load; and transgingival heights ranging from 1.7–2.8 mm were biomechanically optimal for a screwed implant.