Finite element analysis of deflections in major connectors for maxillary RPDs.
OBJECTIVE
The effect of major connector design on deflection in maxillary removable partial denture (RPD) frameworks under simulated occlusal loading was analyzed by means of three-dimensional finite element models.


METHODS
Thirteen maxillary major connectors were produced for a Kennedy Class II case. Eleven frameworks consisted of posterior palatal straps with different anteroposterior widths at the midline. Anteroposterior and horseshoe bars were also constructed for comparison. In each framework, the occlusal rest on the abutment adjacent to the edentulous ridge was fixed in a vertical direction, and the rest on the contralateral side was fixed in all directions. A biting force of 20 N was vertically distributed simultaneously on each of the three missing posterior teeth locations.


RESULTS
For the posterior palatal straps, the maximum vertical displacement at the saddle and the buccal displacement at both the saddle and the rest adjacent to the saddle decreased as their connector width increased from 6 to 29 mm, whereas maximum distal displacements were insensitive to the connector width. The posterior straps with anteroposterior widths of more than 18 mm revealed comparable rigidity to the anteroposterior bar. The horseshoe bar and the posterior straps with smaller widths demonstrated greater displacements than the other frameworks.


CONCLUSIONS
The rigid connectors proved to be the most effective in transmitting applied occlusal forces to the contralateral side of the framework.
Eto
Miho
M
Department of Masticatory Function Rehabilitation, Division of Oral Health Sciences, Tokyo Medical and Dental University, Japan.
Wakabayashi
Noriyuki
N
Ohyama
Takashi
T
D001732:Bite Force; D019245:Compressive Strength; D003198:Computer Simulation; D003799:Dental Stress Analysis / Q000379:methods*; D003779:Denture Design; D003781:Denture Retention / Q000295:instrumentation*; D003832:Denture, Partial, Removable; D008437:Maxilla; D013718:Tensile Strength