Shear bond strength of orthodontic bonding resins to porcelain; an in vitro study.
- Author:
Jin Hwan KO
1
;
Ki Soo LEE
Author Information
1. Department of Orthodontics, College of Dentistry, Kyung Hee University, Korea.
- Publication Type:In Vitro ; Original Article
- MeSH:
Dental Cements;
Dental Enamel;
Dental Porcelain*;
Humans;
Hydrofluoric Acid;
Orthodontic Brackets;
Shear Strength
- From:Korean Journal of Orthodontics
1992;22(1):43-65
- CountryRepublic of Korea
- Language:Korean
-
Abstract:
Bonding orthodontic adhesive resins to glazed porcelain surface is not attainable. The aim of this investigation was to examine, in vitro, the effect of three methods of porcelain surface pretreatment on the shear bond strength of orthodontic adhesives, and to compare the shear strength of orthodontic bracket bonding to porcelain surface by the best results that to human enamel. Porcelain disks (Ceramco((TM)) and Vita((TM))) baked in the laboratory were roughened by sandpapers, #320, #600, #800, #1000 and #1200, and were pretreated with silane and dried at the various temperatures, room temperature, 50degreesC, 70degreesC and 90degreesC, and were etched by 3% hydrofluoric acid solution for 1, 3, 5, 7, and 9 minutes, orthodontic adhesives (System 1 +((TM)) and Unite((TM))) were applied on them, and shear bond strengths were measured by Instron. The best results of pretreatment of each method were determined by the shear bond strengths. Again, porcelain disks were pretreated by the determined best results and human enamel were etched by 37% hydrofluoric acid solution, orthodontic brackets were bonded on them by the orthodontic adhesives, and the shear bond strengths were measured and compared between them. 1. Roughening porcelain surfaces with coarse sandpaper (#300) showed higher shear bond strength than that with finer sandpapers, but it (22.44 Kgf/cm2) was distinguishably low compared to that from etched human enamel (144.11 Kgf/cm2). 2. There were disparities in shear bond strengths upon the orthodontic resins, which was presumably related to the contents of fillers in orthodontic adhesive resins. Also there were disparities in shear bond strength upon the porcelains which had different composition. 3. Silane enhanced the shear bond strength of orthodontic resins to porcelain surfaces (25.20 Kgf/cm2 at 50degreesC), which was markedly low compared to that from etched human enamel. 4. Etched porcelain surface with 3% hydrofluoric acid solution for 1 to 9 minutes showed no difference in shear bonding strength of orthodontic adhesive resins. Shear bond strength from etched porcelain (97.43-120.72 Kgf/cm2) were as high as clinically available, but low compared to that from etched human enamel. 5. Roughening with #300 sandpaper and etching by 3% hydrofluoric acid followed silane application on porcelain surface showed lower shear bond strength than etched human enamel, but were as high as clinically useful. 6. The results suggest that etching porcelain surface by 3% hydrofluoric acid solution might provide comparatively high shear bond strength as much as clinically favorable.
