Effects of Air Abrasive Polishing on Iron Ion Release from Different Metal Self-Ligating Orthodontic Brackets

Treatment with fixed orthodontic appliances compromises the oral hygiene and increases the risk of plaque-related disorders and dental staining in addition to corrosion and corrosion byproduct: ions. The aim of this study was the assessment of the effects of air polishing on Iron ion (Fe) release from stainless steel self ligating brackets.

A total of 160 self-ligating stainless-steel brackets of 4 brands Damon^® Q™ (Damon^® Q™, Ormco, Orange, CA, USA), Discovery^® SL 2.0 (Dentaraum, Ispringen, Germany), Leone^® F1000 (SLB; F1000, Leone SpA, Sesto Florentino, Florentino, Italy) and Lotus Plus^® (Lotus plus, Orthotechnology co., Brazil) were exposed to different time of air abrasion polishing (0, 5, 10, 20 seconds) and then immersed in artificial saliva with pH value 6.75 and was incubated at 37°C for 28 days. Fe ion release was assessed using atomic absorption spectrophotometer at 7 days, 14 days and 28 days and the accumulative effect were calculated. Scanning electron microscope (SEM) was used to assess the surface changes and microtopography after polishing for the randomly selected sample. Analysis of variance test (ANOVA) and Tukey's (HSD) test was used to identify the significant difference among the studied groups where the level of significance was set at p ≤ 0.05.

The results revealed that all brands showed a significant increase in Fe ion release concomitant with an increase in the polishing time. Damon^® Q™ show the least amount of Fe ion release.

The air polishing procedure enhanced the amount of Fe ion release to a subtoxic level and could be used in adult patients using 5 sec recommended time of polishing with prolonged intervals between the visits.