Force Degradation Of Elastomeric Chains By Instantaneous Prestretching In Vitro

Object: The study aims at exploring the initial force of elastomeric chains by instantaneous prestretching and its force degradation to guide clinical practice in order to facilitate.Method: With the mechanical measuring instrument, we meassure the initial force by different connector types (short-range, medium range, the length range), various circles (1,2,3). Rest them in the 37℃artificial saliva, and meassure the force in different time pots. And analyzed the data by statistical computer programs.Conclusion:1. In the case of stretching the same distance, the elastomeric chains by prestretching have lower initial foce comparing to the normal ones (controlled group).2. In the case of stretching the same distance,the elastomeric chains by prestretching have smaller deegradation rate,and larger percentage of the remaining force comparing to the normal ones(controlled group).3. There is no significant differences between the prestretched elastomeric chains from different types of the connectors or the numbers of the cycles.4. Facing the various needs of anchorage from various patients, we, the orthodontist, can take the Table 3.1 to select the most appropriate group of the intramaxillary elastic chains as a reference.