Bond Strength of Different Adhesive Materials to Root Canal Dentin

Objectives: The aim of the present study was to evaluate regional microtensile bond strengths (mTBS) to root canal dentin using different adhesive systems- two dentin adhesives, one resin cement and one adhesive root canal sealer. Methods: 120 human single rooted teeth were used. Crowns were removed at the CEJ. The roots were bisected along their long axis and sectioned into three thirds: apical (a), middle (m) and coronal (c). Flat root dentin specimens were prepared. The specimens were randomly assigned to four experimental groups of ten samples each: Group S: Syntac; group F: Futurabond NR; group P: Panavia F 2.0; group R: Resilon. The different adhesive materials were applied as recommended by the manufacturer. A composite build up (Ø 1mm) was created over each root canal section to allow mTBS tests. Bond strength was measured using a special device in an universal testing machine. Results: For the four test series following mTBS were evaluated (mean value and standard deviation in MPa):

 

Group S			Group F			Group P			Group R
a	m	c	a	m	c	a	m	c	a	m	c
6.37	10.65	15.62	8.38	10.03	11.49	4.82	8.18	12.63	4.66	8.20	10.22
+/-2.24	+/-2.74	+/-3.55	+/-2.27	+/-3.23	+/-2.98	+/-1.67	+/-3.03	+/-2.71	+/-1.56	+/-3.09	+/-2.17

Statistical analysis showed a significant influence of the used materials and the different regions on mTBS (p< 0.001, ANOVA). In each group significantly increased mTBS were observed in the coronal third of the root (p<0.05, Tukeys test). Conclusions: It can be concluded that all adhesive materials - bonding agents, the resin cement and the adhesive root canal sealer - used in this study were able to establish bond strength on root canal dentin. Regional variations of dentin modified mTBS in all groups.