Content area
Full Text
This review of occlusal considerations for implant-supported complete dentures reflects the majority opinion of authors according to clinical observations and research-documented evidence. Occlusal concepts are presented for the implant-supported complete dentures regarding analysis of loads applied to dental implants, location and number of implants, occlusal materials, and occlusal scheme.
KEY WORDS
Complete denture supported by implants
Occlusal materials
Occlusal schemes
Occlusal forces
INTRODUCTION
It is known that natural teeth have periodontal ligament receptors that protect the teeth and periodontium from excessive occlusal forces, which can cause trauma to supporting tissues and bone. Although many factors are involved in the neuromuscular reflex actions in natural teeth, there are no specific defense mechanisms against occlusal forces in implant-supported complete dentures.1 Complications (prosthetic or bony support) reported in follow-up studies underline occlusion as a determining factor for success or failure.2
For implant placement and fabrication of implant-supported complete dentures, several factors are important: the number and position of implants, the available implant surfaces for load transmission on the jaw bone, the relation of the length of the superstructure to the implant body, and the establishment of correct occlusion.3 The choice of an occlusal scheme for implant-supported complete dentures is often controversial. Almost all guidelines are based on those developed with natural teeth, and there are no published clinical studies comparing the occlusal theories.
This study reviews the occlusal concept choices for implantsupported complete dentures regarding analysis of loads applied to dental implants, location and number of implants, occlusal materials, and occlusal scheme.
ANALYSIS OF LOADS APPLIED TO DENTAL IMPLANTS
A dental implant is subjected to mechanical forces because of the loading placed on the prosthesis. Forces are described as compressive, tensile, and shear. Compressive forces tend to maintain the integrity of an implant. In general, the implant-supported complete dentures best accommodate compressive forces, whereas shear and tensile forces tend to distract or disrupt an implant interface.4
The manner in which a force is distributed over a surface is referred to as mechanical stress.5 The magnitude of stress is dependent on 2 variables: force magnitude and cross-sectional area. A dentist can control the force magnitude, which depends on cantilever length and offset loads. The cross-sectional area is defined as the surface that participates significantly in load bearing...