COMPARING THE STABILITY OF CAST METAL POST AND CORE WITH GLASS FIBER POST MANUFACTURED BY CAD/CAM (IN VITRO STUDY)

The dentist often resorts to post and cores for restoration of damaged teeth due to endodontic treatments and previous restorations in order to prepare them to receive the final restoration. A large number of different systems have appeared for this purpose including cast metal post, cores, and glass fiber post; however, the stability of post and cores is one of the problems that faces the dentist when use them. This controlled in vitro experimental study aimed to compare the stability of conventional cast metal post and cores with glass fiber post and cores manufactured using TRILOR fiber discs milled by CAD/CAM. Thirty extracted single-rooted lower first premolars, endodontically treated and prepared to receive the posts, were randomly divided into two groups. Each group included 15 premolars, the post and cores of both groups were waxed, the samples of first group were scanned (CAD star scanner, Austria) and milled by CAD/CAM (ROLAND/DWX-52, Japan) using glass fiber discs (TRILOR, BIOLOREN, Italy) samples of second group were manufactured by lost wax technique using NiCr alloy (4all, ivoclar vivadent). All the posts were cemented using self-adhesive resin cement. Removal strength tests were carried out using the general mechanical tests device (testometric) which located in the Research and Industrial Testing Center in Damascus. After conducting the statistical test (T Student), we found that the mean of milled fiber glass posts group was (132.13N) while the mean of cast metal posts was (70.60N), so removal strength was significantly higher (p<0.05) in the CAD/CAM post groups than in the groups with cast metal posts. The fiber glass post and cores made using CAD/CAM was more resistant and therefore more stable "than the cast metal post and cores.