The evaluation of bond strengths of different post systems in horizontally oval shaped root canals shaped with different preparation techniques

Restoration need posts for retention in teeth which is endodontically treated and has heavy loss of dentin. Retention of post to root canal, is a crucial factor on long-term prognosis for the restoration. It is well known that, post retention is less oval-shaped canals. For overcome this difficulty, different preparation instruments and materials, cavity shape and post meterials heve been proposed. The aim of this study was to compare different preparation techniques, post materials and post shapes in oval-shaped root canals for gaining better results for retention. In this study, ninety extracted single rooted human teeth which have horrizontally oval-shaped root canals were used. The root surfaces were cleaned and then crowns were cut out from the cementoenamel junction. The specimens were arranged in 3 main groups and root canal preparation were applied either with hand preparation, ProTaper or SAF, then were obturated with gutta-percha. Post preparation was applied to 3 main groups and these groups were divided into 3 subgroups, and then traditional fiber posts, ovoid fiber posts (Ellipson), and light transmitting posts (Luminex) were cemented with self adhesive resin cement to these subgroups. After 24 hours, specimens were sectioned for conducting `push out? test. Push out test was applied to the sectioned samples. The recordings for each group and subgroup were compared with one way (ANOVA) analysis of variance and Post Hoc Tukey test statistically. Highest bonding strength of preperation techniques were observed in SAF prepared group compared to hand or ProTaper prepared group. However statistically no significant difference were detected among the groups. Highest bonding strength of each post system and preparation technique were detected in the coronal part of the roots, the least strength were observed in the apical level. Significant differences were obtained between the groups for different root levels. Highest bond strength were obtained in Luminex light transmitted post group. It can be concluded that use of Luminex light transmitted posts has had more increased bond strength to root canal dentin compared to traditional circular shaped posts (Snowpost) and oval shaped posts (Ellipson) in oval shaped canals. The preparation technique has no effect on the bond strength of the posts to the root canal dentin in oval shaped canals. Key Words: SAF, oval shaped root canals, fiber post, Ellipson post, Luminex post.