Detection of thermal deformation on artificial tooth using holographic interferometry single exposure technique

Abstract

Holographic interferometry technique with a single transmission exposure was used to detect thermal deformation on an artificial tooth. This is a non-invasive testing and produce very high accuracy in temporal deformation detection. Two artificial tooth: the second incisive anterior and the first upper molar tooth, from acrylic and ceramic materials, were employed as objects in the holography system. He-Ne gas laser was utilized as a source of illumination. A soldering iron was conducted as a source of heat. The hologram was first recorded on the holographic film. The exposed film was then developed manually in the dark room. The hologram film was later used as an object for reconstruction process. The real part of the hologram was permanently recorded using digital camera. The hologram was captured before and after heating with soldering iron. The difference of fringes distance was analyzed using a Matrox Inspector 2.1 software. The observation result show that the fringe pattern before and after heated are entirely difference due to the volume expansion. In general both fringes patterns after heating tend to be linear and the fringe spacing become narrow and close to each other. The distance change on incisive tooth is found to be 40 micron and on the upper molar tooth is 17.5 micron.