Influence of thickness and area of reline on the stress distribution in peri-implant bone during the healing period: a three-dimensional finite element analysis.

The current study used finite element analysis to evaluate how the thickness of reline material and the area of its placement in conventional complete dentures affected the stress distribution in peri-implant bone during function in the healing period. For this study, three-dimensional models were created to simulate a severely resorbed mandible with two implants placed recently in the anterior region. Two of these models received a layer of soft liner material that covered the entire length of the denture base (1.5 mm or 3.0 mm); for the other sample models, soft liner material was placed (in thicknesses of 1.5 mm or 3.0 mm) in the implant region only. The models were exported to mechanical simulation software; two simulations were performed by placing a load in the mandibular right canine (35 N) and the mandibular right first molar (50 N). Data were quantitatively and qualitatively evaluated by means of maximum principal stress. In all cases, models that received 3.0 mm of soft liner material showed lower values of stress concentration than those receiving 1.5 mm of soft liner material. Likewise, localized application of soft liner in the implant region showed lower stress concentration compared with models in which the entire denture base was relined. These results indicate that the thickness and area of reline in conventional complete dentures has a direct effect on stress distribution in the peri-implant bone tissue during the healing period.