The human need for safe and effective dental implants is well-recognized. Although many implant designs have been tested and are in use today, a large number have resulted in clinical failure. These failures appear to be due to biomechanical effects, as well as biocompatibility and surgical factors. A unified approach is proposed using multidisciplinary systems technology, for the study of the biomechanical interactions between dental implants and host tissues. The approach progresses from biomechanical modeling and analysis, supported by experimental investigations, through implant design development, clinical verification, and education of the dental practitioner. The result of the biomechanical modeling, analysis, and experimental phases would be the development of scientific design criteria for implants. Implant designs meeting these criteria would be generated, fabricated, and tested in animals. After design acceptance, these implants would be tested in humans, using efficient and safe surgical and restorative procedures. Finally, educational media and instructional courses would be developed for training dental practitioners in the use of the resulting implants.

AbstractA model describing the elastic behavior of dental amalgam as a composite material has been developed using elastic theory for quasi‐homogeneous, quasi‐isotropic systems. The elastic constants of the composite amalgam can be computed using Voigt‐Reuss and Hashin‐Shtrikman methods if the relative volume fractions and the elastic constants of the constituent phases are known. This model also relates the elastic behavior of the amalgam to manipulation during preparation. The elastic constants of several spherical and cut amalgams, as well as the constituent γ, γ1, and γ2 alloys, have been measured in the 0–50 kilobar range using a solid media pressure apparatus and an ultrasonic interferometer. High pressure studies are necessary so that the effects of porosity can be assessed. Calculations based on this model include the effects of porosity as well as the Hg content.

The pressure variations of the elastic constants of the constituent phases of dental amalgam (γ–Ag 3 Sn, γ 1 –Ag 2 Hg 3 , and γ 2 –HgSn 7–8 ) were investigated in the 0–50 kilobar range. The velocities of propagation of longitudinal and transverse ultrasonic waves were measured using an ultrasonic interferometer and a solid media pressure apparatus. Computer analysis yields the pressure dependence of the bulk modulus, shear modulus, Young's modulus, and Poisson's ratio; atmospheric pressure values are obtained by back extrapolation from the high pressure measurements. The values of these elastic constants are related to the crystallographic structures of the individual alloys. The possibility of high pressure first order polymorphic transitions in γ and γ 2 is also discussed.

AbstractThe pressure dependence of the elastic constants of dental amalgam has been examined in the 0–50 kilobar range using a solid media, pressure apparatus coupled with an ultrasonic interferometer. Computer analysis of the measured longitudinal and shear ultrasonic wave velocities yields the pressure dependence of the bulk, shear and Young's moduli and Poisson's ratio. Samples were prepared with varying compositions from micro‐cut and spherical dental alloys. The elastic behavior of these samples can be directly related to the sample structure and composition as well as to the manipulation during preparation. In addition, an estimate can be made of the volume concentration of porosity.