Abstract
Background and Objectives
This study compared the surface morphology as well as the biocompatibility of dental root cementum treated with Er:YAG laser irradiation alone and with the laser irradiation followed by chemical and/or mechanical conditioning.
Study Design/Materials and Methods
Healthy cementum plates were randomly assigned to the following control and treatment groups: (1) untreated control (C), (2) Er:YAG laser irradiation (L), (3) laser plus tetracycline HCl (TC) placement (L+TP), (4) laser plus TC burnishing (L+TB), (5) laser plus EDTA gel placement (L+EP), (6) laser plus EDTA gel burnishing (L+EB), (7) laser plus saline solution burnishing (L+SB), and (8) laser plus minocycline–HCl paste placement (L+MP). Specimens were subjected to scanning electron microscopy (SEM), histological observation and attachment assay using periodontal ligament (PDL) fibroblasts.
Results
The laser irradiation produced a thin affected layer (5.7 µm thickness) with a superficial microstructure on the cementum surface. The characteristic microstructures of the lased surface were fragile and could be removed by chemical and/or mechanical conditioning treatments. The L+TB group exhibited marked exposure of collagen fibers after removal of the microstructures on the lased surface. The L+EP group presented a peculiar, smooth surface without exposure of collagen fibers and a uniform arrangement of spherical microparticles on the ultra‐high magnification of SEM. In cell attachment assay, the L+TB group exhibited the greatest number of attached cells among all the groups, followed by the L+EP, L+SB and control group. The laser alone group exhibited the lowest number of cells.
Conclusions
The characteristic microstructure of the root cementum surface after Er:YAG laser irradiation has a tendency to hinder the early attachment of PDL cells. However, chemical and/or mechanical root conditioning treatment may improve and increase the biocompatibility of the Er:YAG laser‐treated root cementum by removing the microstructures of the surface and/or further exposing the collagen fibers. Laser Surg. Med. 40:211–222, 2008. © 2008 Wiley‐Liss, Inc.