Effects of dentin surface modifications treated with Er:YAG and Nd:YAG laser irradiation on fibroblast cell adhesion

The purpose of this in vitro study was to evaluate the effect of surface modifications induced by erbium (Er):YAG and neodymium (Nd):YAG laser irradiation on cell adhesion by comparing it to that of conventional methods for surface preparation after root-end resection.

Many studies have been seeking a favorable method to produce a resected root end with optimal conditions for cell response. However, little improvement has been achieved. This study evaluated the biocompatibilities of resected root surfaces after Er:YAG or Nd:YAG laser irradiation on initial cell adhesion.

Dentin disks were divided into three groups. Group A was left untreated, Group B was treated with Er:YAG laser irradiation (60 mJ/pulse, 10 pps, 60 sec), and Group C with Nd:YAG laser irradiation (60 mJ/pulse, 10 pps, 60 sec). After laser irradiation, the dentin disks were incubated with NIH/3T3 fibroblasts cultured in Dulbecco's modified Eagle's medium. A morphological analysis of the dentin surface and cell adhesion was observed under a scanning electron microscope. Surface roughness was measured using a confocal laser scanning microscope. The statistical analysis was undertaken using ANOVA at a level of significance of 5% (p<0.05).

Morphological analysis and roughness measurement showed that dentin surfaces treated with Er:YAG laser irradiation were rougher than those in Groups A and C. Group B (Er:YAG) exhibited the greatest number of attached cells among all groups after 12 and 24 h.

Morphological alteration induced by Er:YAG laser irradiation showed a favorable effect on the attachment of fibroblasts to dentin surfaces.