Attachment of cultured fibroblasts and ultrastructural analysis of simulated cervical resorptions treated with high-power lasers and MTA.

Objective: The present study evaluated the fibroblast attachment and the morphologic changes of simulated cervical root resorptions after irradiation with high-power lasers and the use of mineral trioxide aggregate (MTA).

Study Design: Standardized cavities were done on the coronal third of 40 single-rooted teeth and assigned into 4 groups according to the treatment applied: (1) untreated control, (2) use of MTA, (3) irradiation with Er:YAG laser (42 mJ, 10 Hz, 10 s), and (4) irradiation with high-power diode laser (1 W, 10 s). Fragments were prepared for SEM analysis: 6 samples of each group were plated with human gingival fibroblasts and 4 samples were used for ultrastructural analysis.

Results: The cells' attachment was in decreasing order: G3 > G4 > G1> G2, with statistical differences among all groups (P < .05). The samples irradiated with Er:YAG exhibited roughness on the dentinal surface, no smear layer, and open dentinal tubules; those irradiated with diode laser exhibited a smooth surface, more smear layer, and closed dentinal tubules; and the control group showed high amount of smear layer and closed dentin tubules.

Conclusions: Irradiation with Er:YAG and diode lasers caused morphologic changes on the dentinal surfaces of simulated resorptions that favored cells' adhesion. MTA showed lower biocompatibility than irradiated groups but allowed cells' adhesion.