Comparative Evaluation of Wettability and Contact Angle Between Endodontic Sealers and Root Canal Lumen After Using Different Irrigants: A Goniometric Study

Introduction The success of root canal treatment depends on effective chemomechanical preparation and the ability of the obturation materials to establish a durable seal with the root canal dentin. The physicochemical interaction between root canal irrigants and endodontic sealers influences sealer wettability, which plays an important role in dentinal adaptation and sealing ability. Contact angle measurement is a reliable method for evaluating wettability, with lower contact angle values indicating greater spreading ability and surface affinity. The present study evaluated the influence of two commonly used irrigants on the wettability of different endodontic sealers. Aim The aim of the study is to comparatively evaluate the wettability and contact angle of zinc oxide eugenol, calcium hydroxide-based, and epoxy resin-based (AH Plus) endodontic sealers on root canal dentin following irrigation with normal saline and 3.25% sodium hypochlorite using an optical goniometer. Materials and methods Thirty extracted human single-rooted permanent teeth were selected according to predefined inclusion and exclusion criteria. Following access cavity preparation and working length determination, biomechanical preparation was performed using 30 K hand files followed by Pro taper files up to F2 with either normal saline or 3.25% sodium hypochlorite as the irrigant. The specimens were divided into two main groups based on the irrigant used: Group A (Normal Saline) and Group B (3.25% Sodium Hypochlorite) (n = 30 each). Each group was further subdivided into three subgroups (n = 10): A1/B1 (Zinc Oxide-Eugenol Sealer), A2/B2 (Calcium Hydroxide-Based Sealer), and A3/B3 (AH Plus Sealer). A standardized 9-µL droplet of each freshly mixed sealer was dispensed onto the root canal lumen, and the contact angle was measured using an optical goniometer. Statistical analysis was performed using one-way analysis of variance, Tukey's post hoc test, and Student's unpaired t-test, with statistical significance set at p < 0.05. Results Significant differences in contact angle and wettability were observed among all experimental groups. Group A3 (AH Plus Sealer) demonstrated superior wettability following normal saline irrigation, whereas Group A2 (Calcium Hydroxide-Based Sealer) showed the poorest wettability. Following sodium hypochlorite irrigation, Group B3 (AH Plus Sealer) exhibited the highest wettability, followed by Group B1 (Zinc Oxide Eugenol Sealer), while Group B2 (Calcium Hydroxide-Based Sealer) showed minimal improvement. Sodium hypochlorite significantly enhanced the wettability of AH Plus and zinc oxide eugenol sealers compared with saline irrigation. Conclusion Group B3 (AH Plus Sealer) demonstrated the most favorable wettability among all evaluated groups. AH Plus showed superior surface characteristics, zinc oxide eugenol exhibited moderate wettability, and calcium hydroxide-based sealer demonstrated poor wettability. The combination of sodium hypochlorite irrigation and AH Plus sealer may improve sealer adaptation and obturation quality.