Endodontic Irrigation Protocols: Effects on Bonding of Adhesive Systems to Coronal Enamel and Dentin

To evaluate the influence of endodontic irrigation protocols on bond strength of total-etch and self-etch adhesive systems to coronal enamel and dentin.

A total of 66 coronal slices from 11 permanent molars were assigned to six groups (n = 11): endodontic irrigation protocols (5% sodium hypochlorite + 17% EDTA; 2% chlorhexidine gel + saline solution + 17% EDTA or no solution - control) and adhesive systems (Adper Single Bond 2 or Clearfil SE Bond). Dental slices were exposed to endodontic irrigation protocols for 30-minute prior to the application of the adhesive systems. Starch tubes were placed over the enamel and the dentin surfaces of each slice (2-4 tubes in each substrate) and filled with Filtek Z350 XT (3M ESPE) to build the microshear bond strength (µSBS) specimens (0.72 mm² sectional area). After 24 hours of water storage (37°C), µSBS test was performed. Bond strength data (MPa) were analyzed by two-way ANOVA, separately for enamel and dentin (α = 0.05).

µSBS means were not influenced by endodontic irrigation protocols in enamel (p = 0.12) nor dentin (p = 0.49). Clearfil SE Bond system presented higher µSBS values than Adper Single Bond 2 both on enamel (p = 0.024) and dentin (p = 0.005).

Endodontic irrigation protocols (5% sodium hypochlorite or 2% chlorhexidine gel + saline solution combined with 17% EDTA) do not jeopardize the bond strength of adhesive systems to coronal enamel and dentin.

The results of this in vitro study suggest that endodontic irrigation protocols do not impair on bonding effectiveness of adhesive systems to coronal enamel and dentin. (J Esthet Restor Dent 29:222-228, 2017).