Evaluation of Nanobubble Water Irrigation For Removing Biofilm-Mimicking Hydrogel in Premolars With Type II Canal Systems

Objective: The purpose of this in vitro study was to evaluate the efficacy of nanobubble water (NBW) irrigation for removal of a biofilm-mimicking hydrogel from premolars with Vertucci Type II canal systems and to compare its performance across different irrigant activation techniques. Materials and Methods: Extracted human premolars (n = 70) with confirmed Vertucci Type II canal configurations were instrumented using a standardized rotary protocol. A fluorescently labeled biofilm-mimicking hydrogel was introduced into the root canal system and allowed to stabilize prior to irrigation activation techniques. Specimens were randomly assigned to experimental groups based on irrigant type, nanobubble water or deionized water, and activation method, including sonic activation, passive ultrasonic irrigation, and laser-activated irrigation. A non-irrigated control group was also included. Following completion of the assigned irrigation or control protocol, each specimen was placed into a black 5 mL vial containing 2 mL of deionized water. Each specimen was then instrumented with an XP Shaper file for 30 seconds to help dislodge residual hydrogel from the canal walls, followed by vortexing to disperse the released fluorescent hydrogel into solution. A 200µL aliquot was then pipetted from each vial and analyzed using fluorescence spectroscopy to measure relative fluorescence units (RFUs). Lower RFU values indicated less residual hydrogel and therefore greater hydrogel removal. Duplicate fluorescence readings were averaged for each specimen prior to statistical analysis. Data were analyzed at α = 0.05. Normality was assessed using the Shapiro–Wilk test, and group differences were evaluated using Welch’s one-way ANOVA with Welch-compatible post hoc comparisons. Results: Residual hydrogel fluorescence differed significantly among the seven irrigation protocols. Shapiro–Wilk testing demonstrated that all groups satisfied the assumption of normality except DIW + SA, which showed a significant deviation from normality (W = 0.7702, p = 0.0063). Therefore, fluorescence values were compared using Welch’s one-way ANOVA, which demonstrated a statistically significant difference in mean fluorescence across groups (p < 0.0001). Post hoc Welch-compatible pairwise comparisons showed that NBW + Laser exhibited significantly lower fluorescence values than Control, NBW + PUI, NBW + SA, DIW + PUI, DIW + SA, and DIW + Laser (p < 0.05 to p < 0.0001). Additionally, DIW + Laser demonstrated significantly lower fluorescence than DIW + SA (p < 0.01). Conclusions: Within the limitations of this in vitro study, irrigation protocol significantly influenced removal of biofilm-mimicking hydrogel from premolars with Vertucci Type II canal systems. The NBW + Laser group demonstrated the lowest residual fluorescence values, indicating the greatest hydrogel removal among the tested protocols. The finding that DIW + Laser also produced significantly lower fluorescence than DIW + SA suggests that laser activation enhanced hydrogel removal even when deionized water was used as the irrigant. Overall, these findings support continued investigation of nanobubble water, particularly when combined with laser activation, as a potential strategy for improving physical debridement within anatomically complex root canal systems.

Author dc:creator

• Johnson, Cole

Advisor dc:contributor.advisor

• Govindool, Sharaschandra

• Nanobubble water
• Endodontic irrigation
• Biofilm-mimicking hydrogel

Language dc:language.iso

en_US

Handle dc:identifier.uri

https://hdl.handle.net/1805/56847

OAI identifier oai:identifier

oai:scholarworks.indianapolis.iu.edu:1805/56847