LOADS IN DENTAL IMPLANTS

Short Communication

Abstract

Dental implants undergo occlusal loads when placed in occlusion; such loads may vary dramatically in magnitude, frequency, and duration depending on the patient’s parafunctional habits. A force was described by Sir Isaac Newton in 1687 in what is now referred to as Newton’s laws of motion. In his second law, Newton stated that the acceleration of a body is inversely proportional to its mass and directly proportional to the force that caused the acceleration. This law is expressed as F = ma.A force applied to a dental implant is directed clinically along loading axes that exist in implant dentistry: mesiodistal, faciolingual, and occlusal apical. Forces may be described as compressive, tensile, or shear. The implant body design transmits the occlusal load to the bone. Threaded or finned dental implants impart a combination of all three force types at the interface under the action of a single occlusal load.Cylinder implants in particular are at highest risk for harmful shear loads at the implant-to- tissue interface under an occlusal load directed along the long axis of the implant body.Hence, cylinder implants require a coating to manage the shear stress.A load applied to a dental implant may induce deformation of the implant and surrounding tissues. Biological tissues may be able to interpret deformation or a manifestation thereof and respond with the initiation of remodelling activity.The greater the magnitude of stress applied to a dental implant system, the greater the difference in strain between the implant material and bone. In such cases, the implant is less likely to stay attached to the bone, and the probability of fibrous tissue ingrowth into the interfacial region to accommodate the range of difference becomes greater. Moment of force or torque is the rotational equivalent of linear force. Torque can act on the tooth/dental implant in three different planes i.e Mesio-distal plane, Facio-lingual plane, Occluso-apical plane. These are called moment arms. These moment arms can also be clinically correlated as occlusal height, cantilever length, and occlusal width.