Mucosa characteristics effect on complete dentures and overdentures stress distribution

Objectives: Evaluate the effect of different mucosa thickness and resilience on stress distribution of complete dentures and implant-retained overdentures using a two-dimensional finite element analysis. Methods: Representative models of edentulous mandible were constructed on AutoCAD software according to groups characteristics. In group PT a model of edentulous mandible supporting a complete denture was obtained while in group IO, a model of edentulous mandible supporting an overdenture over two unsplinted implants with o'ring system was constructed. In each group, mucosa was characterized as hard, resilient and soft according to three different thickness (1, 3 and 5mm), respectively. Evaluation was performed on Ansys software, with 100N vertical load applied on central incisive teeth. The principal stress was used as analysis criteria. Results: Group IO showed higher stress values than group PT regardless thickness and resilience of mucosa. Stress decreased at supporting tissues in both groups as the thickness and resilience of mucosa increased. In relation to supporting tissues, cortical bone showed the highest stress values. Conclusion: The use of an attachment system increases stress values and the thickness and resilience of mucosa are great influence on stress values.

Financial Support: FAPESP (grant numbers: 06/52230-6 and 06/59770-6)