Introduction: The family of erbium laser which has two different wavelengths including
Er:YAG laser (2940 nm) and Er,Cr:YSGG laser (2780 nm) is an effective device for cutting dental
hard tissue due to their high absorption in water and hydroxyapatite that makes them suitable for
cavity preparation. Cavity preparation using laser has some advantages such as reduced pain and
vibration during the procedure and providing patient's comfort which is the key factor in pediatric
dentistry.
Materials and methods: The purpose of the present study is to compare and evaluate the effect
bond prep mode and cutting mode of Er,Cr:YSGG Laser on shear bond strength of glass ionomer
(GI) cement and resin modified glass ionomer (RMGI) filling materials applied on flattened buccal
and lingual surface on forty-eight freshly extracted caries-free human primary molars divided into
2 groups and each group is subdivided into 2 subgroups each according to the mode of preparation:
group 1: bond prep mode Er,Cr:YSGG laser; group 2: Er,Cr:YSGG cutting mode. The samples will
be subjected to universal testing machine.
Results: The mean (SD) values for shear bond strength of Bond prep and cutting modes
regardless of restorative material were 22.9 (5.3) and 20.7 (5.2), respectively. There was no
statistically significant difference between the two preparation modes. There was no statistically
significant difference between Bond prep and cutting modes whether using GI (P-value = 0.433,
Effect size = 0.014) or with RMGI (P-value = 0.051, Effect size = 0.085). Comparison between the
two restorative materials revealed that GI showed statistically significantly lower mean shear bond
strength than RMGI whether using Bond prep mode (P-value <0.001, Effect size = 0.345) or cutting
mode (P-value = 0.001, Effect size = 0.226).
Conclusion: Er,Cr:YSGG laser have adverse effect on the adhesion of RMGI and GI, bond
prep mode is better than cutting mode and RMGI is preferred than GI clinically.