Weinberg L A
Department of Graduate Prosthodontics, College of Dentistry, New York University, New York, USA.
Int J Prosthodont. 1998 Jan-Feb;11(1):55-69.
This paper focuses on the derivation of implant loading forces as influenced by occlusal anatomy. Vertical occlusal forces on cusp inclines produce resultant lines of force that result in lateral rather than vertical forces to the supporting bone.
An analysis of resultant lines of force with different impacting occlusal surfaces was illustrated. Methods were suggested to decrease implant loading by reducing cusp inclines, utilization of cross occlusion, and the modification of occlusal anatomy to provide a continuous 1.5-mm flat fossae, rather than the line angles of the usual cuspal anatomy. The relationship of incisal guidance to the cusp inclines on the adjustable articulator were reviewed. Modification of the incisal pin and articulator settings were suggested to produced a 1.5-mm fossae throughout the prosthesis. Practical laboratory and intraoral occlusal adjustment techniques were suggested to provide a modified centric occlusal anatomy to help decrease implant loading.
Clinical examples were shown to verify the accuracy of the modified settings on the semi-adjustable articulator and the resultant modified occlusal anatomy.
Implant loading can be reduced by modifying the location of the impact area and the occlusal anatomy. Simple modification of the incisal pin and articulator settings can be used to produce a 1.5-mm flat fossae, which results in more vertical forces to the supporting bone. The same procedures are used to reduce cusp inclinations, which effectively lessens the torque exerted on the prosthesis, implant, and bone. A combination of all these factors can prevent implant overload.
