Bonding effects of different adhesive materials with no ferrule effect in the dental restoration with CAD/CAM-fabricated one-piece fiber post-and-core after bypass obturation of oval root canals

Qi Lu; Wang Xing; Wu Pei-ling

doi:10.3969/j.issn.2095-4344.0841

Abstract：BACKGROUND:One-piece glass fiber post-and-core achieves a good sealing between cast-post and core and provides a suitable elastic modulus of the glass fiber material. Therefore, selecting a reasonable bonding system for the CAD/CAM-fabricated fiber post-and-core with no ferrule effect has become an important issue in clinical practice. OBJECTIVE:To compare the bonding effects of three kinds of adhesive materials without ferrule effect in the CAD/CAM-fabricated dental restoration after bypass obturation of oval root canals. METHODS:Ninety extracted first mandibular premolars with the working length set to 14 mm were randomized into three groups (n=30 per group). The root canal was prepared with the ProTaper next nickel titanium system under a dental operating microscope. The bypass obturation with oval root canals was achieved using the warm gutta-percha vertical condensation technique. 1-4 # Pesso drills were used to remove the gum in the root canal, with the preparatory depth of 9 mm, but with no shoulder collar. CAD/CAM technology was used to prepare one-piece fiber post-and-cores which were bonded using the KetacTM Cem Easymix glass ion, ONE-STEP PLUS universal UV-curable adhesive and RelyXTM Unicem 2 self-adhesive resin cement in different groups. The bonding effect of three kinds of adhesive materials was analyzed by using a universal mechanical measuring instrument. RESULTS AND CONCLUSION:Compared with the KetacTM Cem Easymix glass ion group, the debonding force and micro-tensile strength were significantly stronger in the other two groups (P<0.05), while compared with the ONE-STEP PLUS universal UV-curable adhesive group, the debonding force and micro-tensile strength were slightly higher in the RelyXTM Unicem 2 self-adhesive resin cement group, but there was no significant difference between the two groups. To conclude, RelyXTM Unicem 2 self-adhesive resin cement in the absence of ferrule effect can achieve better bonding effect on the CAD/CAM-fabricated one-piece fiber post-and-core after bypass obturation of oval root canals.