Push-out Bond Strength of Two Types of Dental Post Luted with Two Types of Cement at Two Different Root Levels

Abstract

Objective Endodontically treated teeth may require posts for retaining the core and replacing the coronal structures that have been lost. The objective of this study was to evaluate and compare the push-out bond strength between different types of post cemented with different types of luting cement at different types of root level. Materials and Methods In this in-vitro study, a total of 48 single-rooted permanent human teeth were decoronated, and the roots were treated endodontically. Following post space preparation, the sample was divided into four groups (n= 12 each) based on the types of post and cement. Two different types of post [GC everStick ® POST (ES) and Parapost ® Fiber Lux TM (PF)], and two different types of cement [G-CEM TM (G), and RelyX TM Unicem (R)] were used according to the manufacturer’s instructions. All roots were sectioned at the coronal and middle thirds with a thickness of 3±0.1mm. The Push-out bond strength (PBS) test was performed using a universal testing machine at a cross-head speed of 0.5mm/ min. The bond strength values were recorded, and the data were analyzed using the SPSS program. Apart from descriptive statistics, three-way ANOVA was used for the interaction of the independent variables (post, cement, and root level). For differences between the groups, the Mann-Whitney U test was used. A P-value of less than 0.05 was considered significant for all analyses. Results Push-out bond strength of samples at the middle level (11.38±10.31 MPa), with PF posts (11.18±9.98 MPa), and of those luted with RelyX TM Unicem cement (13.26±8.73 MPa) was higher than that of their counterparts. The PBS means of RelyX TM Unicem cement at both root levels were much higher than PBS means of G-CEM TM cement. Three-way ANOVA test revealed a significant effect for each variable with a higher effect of cement (Sum of Squares= 1310.690; P< 0.001). No significant difference (P= 0.153) was found between the coronal and middle parts and between ES and PF posts (P= 0.058). However, a highly significant difference (P< 0.001) was found between RelyX TM Unicem and G-CEM TM cements. Conclusion The type of cement had a significant effect on push-out bond strength with RelyX TM Unicem which had higher values than G-CEM TM . However, the type of post and root level had no significant effect on PBS, although Parapost® Fiber Lux TM and middle root level had higher values than their counterparts.

Fitting of Different Intraradicular Composite Posts to Oval Tooth Root Canals: A Preliminary Assessment

“…The organic matrix often involves methacrylate-based monomers (i.e., BisGMA, UDMA, TEGDMA) and photoinitiators, although the self-adhesive resin cement includes 10-MDP or 4-META acidic monomers that evince self-adhesive properties with respect to tooth tissues [ 47 , 48 , 49 ]. Dual-cured resin cements require multi-step adhesive procedures, with prior conditioning with an etch-and-rinse or self-etch (SE) adhesive [ 50 , 51 ]. However, the contacts between root dentin and acidic adhesive monomers can be impaired by the thick amounts of smear layer, therefore decreasing the mechanical interlocking of the resin cement.…”