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


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.


CONCLUSIONS
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.
Assunção
Wirley Gonçalves
WG
UNESP-São Paulo State University, Araçatuba Dental School, Department of Dental materials and Prosthodontics, São Paulo, Brazil. wirley@foa.unesp.br
Barão
Valentim Adelino Ricardo
VA
Tabata
Lucas Fernando
LF
de Sousa
Edson Antonio Capello
EA
Gomes
Erica Alves
EA
Delben
Juliana Aparecida
JA
D000539:Alveolar Process / Q000502:physiology; D003198:Computer Simulation; D017267:Dental Prosthesis Design; D019094:Dental Prosthesis, Implant-Supported; D003799:Dental Stress Analysis / Q000379:methods; D003781:Denture Retention; D003824:Denture, Complete; D003828:Denture, Overlay; D055119:Elastic Modulus; D020342:Finite Element Analysis; D006801:Humans; D008334:Mandible; D003765:Models, Dental; D009061:Mouth Mucosa / Q000033:anatomy & histology*