An Assessment of the Impact of Erbium Laser and Conventional Etching Techniques on Microleakage, Shear, and Microtensile Bond Strength of Hydrophobic and Hydrophilic Pit and Fissure Sealant – An In vitro Study

Abstract Purpose: In recent years, laser etching has emerged as an alternative to conventional acid etching for enamel surface pretreatment due to its drawbacks. This method can be used as a substitute for preparing pits and fissures before sealing. The study aims to compare the impact of laser etching and conventional etching on microleakage, shear, and microtensile bond strength of hydrophobic and hydrophilic pit and fissure sealants. Methodology: The present in vitro study was performed on 60 healthy premolars which were extracted for orthodontic purposes which was cleaned and disinfected. The teeth were randomly divided into 6 groups, with each group consisting of 10 molars: Group 1 (hydrophobic sealant – acid etched using 35% orthophosphoric acid), Group 2 (hydrophobic sealant – laser etched), Group 3 (hydrophobic sealant – acid etched using 35% orthophosphoric acid + laser etched), Group 4 (hydrophilic sealant – acid etched using 35% orthophosphoric acid), Group 5 (hydrophilic sealant – laser etched), and Group 6 (hydrophilic sealant – acid etched using 35% orthophosphoric acid + laser etched). The etching and sealant placement was done according to the manufacturer’s instructions and analysis protocol. The pit- and fissure-sealed premolars were subjected to thermocycling. For microleakage analysis, dye penetration method was employed and assessed with the help of stereomicroscope. Universal testing machine was used for shear bond and microtensile bond strength analysis. Mode of failure was noted. Results: Among the hydrophobic (Clinpro) and hydrophilic (Wetbond) sealants, the microleakage was highest in conventional etching and the lowest microleakage was observed in the conventional + laser etching group. On comparison, in both the hydrophobic sealant and hydrophilic sealant groups, the mean microtensile bond strength and shear bond strength was highest in the conventional + laser etching group and lowest in the only conventional etching group. Conclusion: Based on the results of this study, it has been concluded that hydrophilic sealant exhibited better efficacy. The combination of laser etching with conventional etching outperformed other subgroups, demonstrating reduced microleakage along with superior shear bond strength and microtensile strength.