Holographic Measurement of Dental Tissue Contraction and Stress, due to Postpolymerization Reaction

Polymerization contraction of dental photo-polymer composites induces internal stress, in a tooth cavity. This stress is measured indirectly by, first, holographic determination of tooth deformation, with consequent calculation of stress using finite element method. Real time holographic technique enabled observation of dental deformation in all stages of polymerization. Specially constructed blue-LED light source was used to polymerize photopolymer composite. We have found that polymerization continues even after illumination is over. Consequently, stress is increased, too.