Comparison between complete denture and implant-retained overdenture: effect of different mucosa thickness and resiliency on stress distribution

Comparison between complete denture and implant-retained overdenture: effect of different mucosa thickness and resiliency on stress distributionBackground:The effect of different mucosa characteristics on stress distribution of complete dentures and overdentures remains unknown.Objective:The aim of this study was to evaluate the effect of different mucosa thickness and resiliency on the stress distribution of complete dentures and implant-retained overdentures using a two-dimensional finite element analysis.Material and methods:Representative models of the edentulous mandible were constructed on AutoCAD software according to the groups' characteristics. In group CD, a model of the 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 an o' ring system was constructed. In each group, mucosa assumed three characteristics of thickness (1, 3 and 5 mm) corresponding to the resiliencies hard, resilient and soft respectively. Evaluation was performed on Ansys software with 100N vertical load applied on central incisor teeth. The principal stress was used as analysis criteria.Results:Group IO showed higher stress values than group CD regardless of mucosal thickness and resiliency. Stress decreased at the supporting tissues in both groups as the thickness and resiliency of mucosa increased. In relation to the supporting tissues, cortical bone showed the highest stress values.Conclusion:It was concluded that the use of an attachment system increases stress values and the thickness and resiliency of mucosa influence more on these values.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP