Effects of plastic bracket primer on the shear bond strengths of orthodontic brackets.

BACKGROUND/PURPOSE: To assess the usefulness of plastic bracket primer (PBP) for improving the bond strength of plastic brackets (PBs) using three types of orthodontic brackets, including PBs, metal brackets (MBs), and ceramic brackets (CBs). MATERIALS AND METHODS: A total of 162 premolars were gathered and divided equally into six groups of 27. Three groups were tested with the application of PBP (PB+, MB+, and CB+), and three groups were tested without primer (groups PB-, MB-, and CB-). All the groups were bonded using BeautiOrtho Bond II self-etching adhesive. The shear bond strength (SBS) was measured and the bond failure mode was evaluated using the adhesive remnant index after debonding. RESULTS: There were significant differences in the mean SBS between groups PB-, MB and CB-, between PB+ and CB+, and between MB+ and CB+. Group PB + had a significantly higher mean SBS than group PB-. The occurrence of bond failure at the enamel and adhesive interface was more frequent in groups PB+ and CB- than in group PB-; and in groups PB+ and CB + than in group MB+. CONCLUSION: Plastic bracket primer can increase the bond strength of PBs to the level of metal brackets, but not to the level of ceramic brackets.

Bond strength of indirect bonded brackets in orthodontic adhesives with different viscosities.

The aim of this study was to assess the effects of three adhesives with different viscosities and an adhesion promoter on the shear bond strength (SBS) of orthodontic brackets bonded to human premolars with an indirect bonding system (IDBS). High, medium and low viscosity IDBSs with and without application of the adhesion promoter were used. The mean SBSs of the high and low viscosity IDBSs were significantly higher than that of the medium viscosity IDBS. Application of the adhesion promoter significantly increased the SBSs. The adhesion promoter significantly increased the surface roughness and free-energy of enamel. Irrespective of application or nonapplication of the adhesion promoter, the high and low viscosity IDBSs are effective for bracket bonding. Use of the medium viscosity IDBS in combination with the adhesion promoter is recommended for obtaining a clinically acceptable SBS.

[Case of anesthesia for laparoscopic cholecystectomy in a patient with a history of frequent anaphylaxis].

Idiopathic anaphylaxis is a rare disease that induces anaphylactic shock without extrinsic incentive. We had a patient with such frequent episodes undergoing laparoscopic cholecystectomy. Steroid was administered both at preoperative and intraoperative periods. Epidural anesthesia and general anesthesia by inhalation anesthesia, which are low risk for anaphylaxis, were used to reduce perioperative stress and restricted usage of drugs even in postoperative period. Consequently, we can safety manage anesthesia without episode of anaphylactic shock. To prepare for anaphylaxis we prepared usual therapeutic drugs for shock and measured serum tryptase, which has longer half-life than that of histamine.