We examined the adhesion of resin composite restorations with the one-step self-etch bonding system to dentin irradiated by Er:YAG laser. We used two one-step self-etch bonding systems and one two-step self-etch bonding system. Flat bovine dentin surfaces were prepared using a model trimmer and water-resistant paper （#600）, and were irradiated with Er:YAG laser （100mJ, 10pps）. Non-irradiated specimens were used as a control. After bonding procedures, the specimens were stored in 37℃ distilled water for 24h. Thereafter, a tensile bond strength test was performed in each group （n＝5）. In the two-step bonding system, a significant difference was found in the tensile bond strength between the non-irradiated dentin and the dentin irradiated by Er:YAG laser, but was not found in the one-step bonding system. It is suggested that with the one-step bonding system, the laser irradiation has a small influence on the adhesion of resin composite restorations to dentin irradiated by Er:YAG laser.
Numerous patients report having problems such as gingival malformation, melanin pigmentation, and frenulum abnormalities in relation to periodontal esthetic dissatisfaction. During clinical treatment, these problems are often solved using periodontal surgery. Recently, the increasing use of treatment using dental lasers has been reported. This article describes esthetic restoration with gingivoplasty using an Er:YAG laser for a patient with irregular marginal gingiva present in the upper left incisor. On inspection, the cement-enamel junction was found to be placed coronally and the clinical crown length was found to be shorter because of occlusal adjustment. Due to enamel caries on the labial side, the patient found this situation to be esthetically dissatisfying. Based on the results of a reevaluation following the initial therapy, gingivoplasty was performed using an Er:YAG laser. After gingival healing, the incisor was restored using a laminate veneer and porcelain fused to a metal restoration. Gingivoplasty using the Er:YAG laser resulted in less bleeding compared with a scalpel, which is an advantage for adjusting a crown temporarily. In addition, wound healing after using the Er:YAG laser was faster than that after using a scalpel. These findings indicate the substantial advantages of using an Er:YAG laser in gingivoplasty. At present, at 5 years after the operation, no gingival regression has been observed in this case.