Nd:YAG laser ablation of enamel for orthodontic use: tensile bond strength and surface modification.
To test the feasibility of Nd:YAG laser ablation for orthodontic use, bovine enamels were ablated at 2.5 and 3.5 W/pulse conditions. Orthodontic brackets were attached on the ablated enamel surface using a self-curing resin. For comparison, a 37% phosphoric acid solution was used to etch the enamel surface. The strength to detach the brackets was estimated for both surface treatments. Modifications of the enamel surfaces were also compared using a scanning electron microscope for both treatments. The tensile bond strengths from the laser-ablated enamels were significantly lower than that from the phosphoric acid-etched enamels. The higher laser power treatment gave a significantly higher bond strength average than with the lower laser power. The laser-ablated surfaces showed the formation of craters. The formation involved melting and solidification of enamel. Each crater had numerous micropores. Microscopically, the ablated surface was smooth, while much of the acid-etched surface contained numerous microspaces.
Kwon
Yong Hoon
YH
Department of Dental Biomaterials, College of Dentistry, Kyungpook National University, 2-188-1 Samduk-dong Jung-gu, Daegu 700-422, Korea.
Kwon
Oh-Won
OW
Kim
Hyung-Il
HI
Kim
Kyo-Han
KH
D000134:Acid Etching, Dental; D000538:Aluminum Silicates; D000818:Animals; D002417:Cattle; D001840:Dental Bonding; D003743:Dental Enamel / Q000187:drug effects / Q000528:radiation effects / Q000648:ultrastructure*; D045662:Dental Etching; D005240:Feasibility Studies; D007834:Lasers; D008855:Microscopy, Electron, Scanning; D009354:Neodymium; D016910:Orthodontic Brackets; D010756:Phosphoric Acids; D016062:Porosity; D019279:Resin Cements / Q000737:chemistry; D013718:Tensile Strength; D015019:Yttrium
D000538:Aluminum Silicates; D010756:Phosphoric Acids; D019279:Resin Cements; D009354:Neodymium; D015019:Yttrium