Microleakage of endodontically treated teeth restored with fiber posts andcomposite cores after cyclic loading: A confocal microscopic study

Statement of problem. The effectiveness of the seal obtained with carbon fi ber posts and composite cores is still unclear. Both 3-step dental adhesive s and self-etching adhesive: primers have been suggested as adhesive system s. Purpose. This confocal microscopic study evaluated the microleakage of teet h endodontically treated and restored with fiber posts and composites with 3 adhesive stems. Material and methods. A total of 72 human mandibular premolars were endodon tically treated and divided into 6 groups of 12 teeth each. The first 3 gro ups were treated with an endodontic sealer containing zinc oxide-eugenol (Z OE) and restored with temporary filling materials containing ZOE. The last 3 groups were treated with ZOE-free materials. Post spaces were prepared in the root canals. The first group treated with ZOE-based materials was rest ored with fiber posts cemented with zinc phosphate cement and composite: co res without adhesive. The other 2 groups of ZOE-treated teeth were restored with fiber poses cemented with All Bond 2 and Panavia 21 dental adhesives, respectively. The last 3 groups were restored with fiber posts cemented wi th All Bond 2, Panavia 21, and Panavia Fluoro cement, respectively. The tee th were loaded intermittently at 2 cycles per second in a moist environment and, after 300,000 cycles, immersed in a solution of Rhodamine B dye for 4 8 hours. A confocal microscope was used to observe the teeth. The ratio bet ween the length of the interfaces observed and the length of the dye penetr ation was evaluated. Two teeth from each group acted as controls and were n ot subjected to dynamic loads. Results. All resin cement groups leaked significantly less than the group c emented with zinc phosphate cement. No statistically significant difference was found between the microleakage of teeth treated with ZOE-based and non -ZOE-based materials. Teeth restored with All Bond 2 dental adhesive leaked significantly less than those restored with Panavia cement. Conclusion. The 3-step dental adhesive (All Bond 2) resulted in a letter ma rginal seal than that obtained with the self-etching primers (Panavia 21 an d Panavia F). The use of endodontic sealers and temporary filling materials containing ZOE had no detrimental effect on the marginal seal of carbon fi ber post/composite resin core restorations.