Microleakage under metal and ceramic brackets after acid etch or laser surface treatment before bonding: An in vitro study.

Abstract

Aim: To compare microleakage beneath ceramic and metal brackets prepared with either acid etching or laser conditioning.

Design: An in vitro study.

Setting: Department of Orthodontics, Faculty of Dentistry, Suez Canal University, Ismailia, Egypt.

Methods: A total of 40 intact human premolars were selected and divided into four equal groups. The groups received the same adhesive-application procedures with different surface treatments and type of brackets: groups 1 (AM) and 3 (AC) underwent phosphoric acid etching; groups 2 (LM) and 4 (LC) underwent laser enamel conditioning using a Er,Cr:YSGG laser. Metal brackets were then bonded to the teeth in groups 1 (AM) and 2 (LM) and ceramic brackets in groups 3 (AC) and 4 (LC). Subsequently, they were placed in fuchsin dye solution. Each premolar was sectioned longitudinally in the occluso-gingival direction at right angles to the brackets. The dye penetration depth was calculated using a stereomicroscope. Microleakage was measured along the enamel-adhesive interface at each section's gingival and occlusal levels. For group comparisons, the Tukey test was utilised as a post hoc test to determine statistical significance between groups. The independent sample t-test was utilised for comparing both subgroups.

Results: The results demonstrated significantly more microleakage under metal and ceramic brackets bonded to enamel prepared with laser conditioning than with acid etching at both the gingival and occlusal surfaces and in total. The AC group exhibited the lowest amount of microleakage, but the LC group demonstrated the highest amount of microleakage.

Conclusion: The ceramic bracket group treated with acid etching exhibited the lowest level of microleakage. Microleakage values on the gingival and occlusal surfaces were higher in both bracket types for the laser etched groups.