ABSTRACT
AIM: To investigate in a laboratory setting the influence of (i) post material (ii) preparation design and (iii) luting agent on the survival probability of root filled teeth, restored with all-ceramic restorations. METHODOLOGY: The crowns of 80 extracted single-rooted human teeth were removed, and root canal treatment was performed including canal filling with Gutta-percha without sealer (crown-down-pressureless technique). The root fillings were removed and the root canal enlarged with a reamer up to size 110. Prefabricated zirconia (CeraPost) or glass-fibre-reinforced posts (DentinPost) were luted using either Ketac Cem or Panavia F 2.0. A core build-up was applied (Clearfil Photocore), and the teeth were prepared with or without a 2-mm ferrule design (n=10 per experimental group). The prepared teeth were scanned (Cerec 3D) and crowns fabricated. After luting of the crowns (Ketac Cem), teeth were subjected to thermocycling (×4000, 5-55 °C) and cyclic loading (1.5 million cycles, 90 N). After load cycling, the teeth were immersed in methyleneblue solution for 24 h and subsequently sectioned in three segments for a dye penetration test. Kaplan-Meyer analysis was performed to assess the survival probability followed by a Cox regression analysis (α=5%). RESULTS: Teeth prepared using the ferrule design as well as the teeth with DentinPosts exhibited a significantly higher survival probability (P<0.05). The luting agent was of minor importance (P>0.05). Most common failure was debonding of posts (CeraPost) and post fracture (DentinPost). The majority of the teeth showed dye penetration after cyclic loading. CONCLUSIONS: Post material and ferrule design were of paramount importance regarding the survival probability of the post and core restorations using pre-fabricated posts. DentinPosts showed superior results versus CeraPosts.
