[Stress distribution in alveolar bone around implants under implant supported overdenture with linear occlusion at lateral occlusion].
OBJECTIVE
To analyze stress distribution in alveolar bone around implants of implant supported overdentures (ISO) with linear occlusion and with anatomic occlusion at lateral mandibular position, and to justify the possibility of decreased injurious force around implants in ISO with linear occlusion.


METHODS
Computerized tomography scan and finite element analysis (FEA) were used to set up two 3-D FEA models of maxillae and mandible with severe residual ridge resorption. The mucosa, linear and anatomic occlusal ISO with bar attachments, and two implants inserted between mandibular foramina were also established in the models. With the condition of imitating the loading of masseter muscles, these models were loaded to simulate the stress distributions in alveolar bone around implants under ISO at lateral occlusion position.


RESULTS
At lateral occlusion, the stress distributions in alveolar bone around implants under ISO with anatomic occlusion were mainly on the lingual and distal sides of the working side implants. However, stress distributions under ISO with linear occlusion were on the distal sides of bilateral implants. Both the stress peaks of ISOs with linear occlusion and with the anatomic one appeared in the working side. In anatomic occlusion model, sigma(z): -6.47 MPa and 6.81 MPa, sigma(1): -4.20 MPa and 7.20 MPa (negative value: compressive stress, positive value: tensile stress); in linear occlusion model, sigma(z): -4.86 MPa and 3.04 MPa, sigma(1): -3.48 MPa and 5.33 MPa.


CONCLUSIONS
At lateral occlusion, when comparing the ISO with two different occlusion schemes, stress peak in alveolar bone around implants in the linear occlusion model was lower than that in the anatomic occlusion model at equal loading situation. Stress in the alveolar bone under ISO with linear occlusion distributed more evenly than that under ISO with anatomic occlusion.
Lü
Ya-Lin
YL
Department of Prosthodontics, Peking University School and Hospital of Stomatology, Beijing, China.
Rong
Qi-Guo
QG
Lou
Hang-Di
HD
Dong
Jian
J
Xu
Jun
J
D003757:Dental Implantation; D003766:Dental Occlusion; D003826:Denture, Complete, Lower; D020342:Finite Element Analysis; D006801:Humans; D008334:Mandible / Q000502:physiology*; D008953:Models, Anatomic; D008954:Models, Biological; D013314:Stress, Mechanical