Estimation of Functional Load Direction to an Implant Using Normal Lines on the Superstructure Occlusal Surface

This study was designed to test the hypothesis that normal lines on the occlusal surface of a superstructure allow estimation of the functional load direction to an implant. Micro-occlusal surface data were obtained using a 3-dimensional laser scanner to identify the normal lines, and strains on the abutment surface were measured with strain gauges under static load using an in vitro model. Measurements were repeated following alterations of the occlusal surface cusp angle. Statistically significant correlations were found between the 2 measurements (P .05), suggesting that normal lines on the occlusal surface can be used to estimate the load direction to an implant.