Development and characterization of biological bovine dentin posts

Abstract This study aimed at evaluating the use of biological dentin post (BDP), achieved by milling bovine root, through the analyses of mechanical and optical properties. BDPs were compared to a glass fiber post (GFP) in the following tests (n = 10): a) elastic modulus (E) and flexural resistance (σ) by three point bending test; b) fracture resistance (FR) by compressive load at 45° and failure pattern; c) light transmitting (LT) ability and their influence on the resin cement's degree of conversion (DC%); d) bond strength (BS) by push-out test and failure pattern. Bovine teeth were decoronated and root length was standardized at 14 mm. The canals were prepared and irrigated with 2.5% NaOCl. GFP's surface was conditioned by 1 min immersion in 24% H 2 O 2 solution before silanization. After root embedment, the root canal walls and the BDP's surface were hybridized (H 3 PO 4 37% + self-cured adhesive) for FR and DC% analyses. Posts were fixed into the root canals using a conventional dual resin cement. For BS test, both posts were luted using the conventional and the self-adhesive cementation. A universal testing machine (EMIC DL2000; 1 mm/min) was employed for the mechanical tests (E, σ, FR and BS). For the LT analysis, opaque polyethylene discs were transfixed by the posts, leaving 10 mm of the posts’ apical section for measurements. Posts’ cervical portion was irradiated (800 mW/cm 2 ) and a spectrometer recorded the number of photons transmitted to previously chosen lateral post regions and at the apical tip. The resin cement DC% was evaluated in several sites of the cement film. After normal distribution were checked (Shapiro-Wilk test), data were submitted to ANOVA (5%) and Scheffe post-hoc test (5%). Results showed that: a) E: BDP > GFP; b) σ: BDP