Load-Deflection Determinations of Specific Wire Configurations

Abstract

A method was devised for the measurement and tabulation of load-deflection values for various wire spring configurations that are commonly used for orthodontic procedures. 1. The deflection of a simple cantilever varies as the third power of the length. 2. The incorporation of a helix into a cantilever at the area of maximum stress markedly increased the deflection. 3. The addition of a helix into a short lever produced a proportionately greater amount of deflection than did the addition of a helix into a long lever. 4. Under continued loading, the rate increased on all springs tested. 5. The load-deflection characteristic of a base arch is approximately the same as that of a simple cantilever. 6. Alteration of the spring height greatly affects the load-deflection values of the retraction springs. Reducing the spring height from 10 mm. to 8 mm., resulted in an increase of approximately 1.5 times as much force being delivered.