HOLOGRAPHIC INTERFEROMETRY AS A METHOD FOR MEASURING STRAIN CAUSED BY POLYMERIZATION SHRINKAGE OF DENTAL COMPOSITE

Polyme-ri-za-tion shrin-ka-ge is one of the most cri-ti-cal pro-per-ti-es of est-he-tic resin-ba-sed den-tal re-sto-ra-ti-ve ma-te-ri-als and may ha-ve a ne-ga-ti-ve im-pact on the-ir cli-ni-cal per-for-man-ce. As the com-po-si-te is ad-he-si-vely bon-ded, con-trac-tion of com-po-si-te ma-te-rial that oc-curs du-ring the polyme-ri-za-tion ca-u-ses stress and strain of hard den-tal tis-su-es. Polyme-ri-za-tion shrin-ka-ge al-so af-fects the ma-in-te-nan-ce of the bon-ded in-ter-fa-ce bet-we-en the com-po-si-te re-sin and den-tal hard tis-su-es. The aim of this study is to pre-sent holographic in-ter-fe-ro-me-try as a met-hod for de-tec-ting and me-a-su-ring strain of den-tal hard tis-sue ca-u-sed by the polyme-ri-za-tion shrin-ka-ge of the den-tal com-po-si-te. Ma-te-ri-als and met-hods: Strain was me-a-su-red ex-pe-ri-men-tally, by real ti-me ho-lo-grap-hic in-ter-fe-ro-me-try, on the ma-xil-lary te-eth. Strain of den-tal tis-sue was de-ter-mi-ned by co-un-ting the interferomen-tic frin-ges that ap-pe-a-red du-ring the polyme-ri-za-tion pro-cess. Re-sults: The defor-ma-tion was re-cor-ded on the co-ro-nal den-tal tis-sue from 2.25 μm to 5.8 μm. The conclu-sion is that ho-lo-grap-hic in-ter-fe-ro-me-try is a non-con-tact, non-de-struc-ti-ve, very preci-se met-hod for me-a-su-ring de-for-ma-tion of hard den-tal tis-su-es that is ca-u-sed by the polyme-ri-za-tion shrin-ka-ge of den-tal com-po-si-te.