COMPARISON OF SHEAR BOND STRENGTH AND SURFACE-STRUCTURE BETWEEN CONVENTIONAL ACID ETCHING AND AIR-ABRASION OF HUMAN ENAMEL

Citation
Me. Olsen et al., COMPARISON OF SHEAR BOND STRENGTH AND SURFACE-STRUCTURE BETWEEN CONVENTIONAL ACID ETCHING AND AIR-ABRASION OF HUMAN ENAMEL, American journal of orthodontics and dentofacial orthopedics, 112(5), 1997, pp. 502-506
Citations number
28
Categorie Soggetti
Dentistry,Oral Surgery & Medicine
ISSN journal
08895406
Volume
112
Issue
5
Year of publication
1997
Pages
502 - 506
Database
ISI
SICI code
0889-5406(1997)112:5<502:COSBSA>2.0.ZU;2-K
Abstract
Recently, air-abrasion technology has been examined for potential appl ications within dentistry, including the field of orthodontics. The pu rpose of this study was to compare the traditional acid-etch technique with an air-abrasion surface preparation technique, with two differen t sizes of abrading particles. The following parameters were evaluated : (a) shear bond strength, (b) bond failure location, and (c) enamel s urface preparation, as viewed through a scanning electron microscope. Sixty extracted human third molars were pumiced and divided into three groups of 20. The first group was etched with a 37% phosphoric acid g el for 30 seconds, rinsed for 30 seconds, and dried for 20 seconds. Th e second and third groups were air-abraded with (a) a 50 mu m particle and (b) a 90 mu m particle of aluminum oxide, with the Micro-etcher m icroabrasion machine (Danville Engineering Inc.). Ail three groups had molar stainless steel orthodontic brackets bonded to the buccal surfa ce of each tooth with Transbond XT bonding system (3M Unitek). A Zwick Universal Testing Machine (Calitek Corp.) was used to determine shear bond strengths. The analysis of variance was used to compare the thre e groups. The Adhesive Remnant Index (ARI) was used to evaluate the re sidual adhesive on the enamel after bracket removal. The chi square te st was used to evaluate differences in the ARI scores among the groups . The significance for all tests was predetermined at p less than or e qual to 0.05. The results indicated that there was a significant diffe rence in shear bond strength among the three groups (p = 0.0001). The Duncan Multiple Range test showed a significant decrease in shear bond strength in the air-abraded groups. The chi square test revealed sign ificant differences among the ARI scores of the acid-etched group and the air-abraded groups (chi(2) = 0.0001), indicating no adhesive remai ned on the enamel surface after debonding when air-abrasion was used. In conclusion, the current findings indicate that enamel surface prepa ration using air-abrasion results in a significant lower bond strength and should not be advocated for routine clinical use as an enamel con ditioner at this time.