Evaluations of Saliva for Nickel release from Conventional Stainless Steel and Nickel free Orthodontic brackets- An Atomic Absorption Spectrophotometric (AAS) study

Introduction: Nickel, which is a potent allergen, is used as a key metallurgical ingredient for manufacturing orthodontic brackets. The study aims at extracting nickel levels in patient's saliva at different time interval. Methods: A total of twenty patients, ten bonded with conventional 3M Stainless steel brackets (group A) and another ten with nickel free brackets(group B). Group B was further divided into two groups of five each, based on different manufacturing companies viz Classic orthodontic and d-tech orthodontics. Three samples of stimulated saliva were collected from each patient at the following intervals: before placement of appliance, one hour after placement and a week after the appliance is being placed. The sample were then analysed with an atomic absorption spectrophotometer for amount of nickel release. Results: Study revealed that the nickel release in 3M stainless brackets in first hour of the bracket placement was very high compared to pre- treatment nickel level. Gradually the release was found to decrease when it was measured after one week. In the second group comprising nickel free brackets by Classic orthodontics the release of nickel gradually increased from the time the appliance was placed in the oral cavity over a period of one week. Third group having d- tech nickel free orthodontic brackets the release in nickel was found to be significantly on higher side after one hour of the appliance placement which eventually decreased over a period of one week. Conclusions: The final outcome of the present study revealed that manufacturing companies and extended time interval has a profound effect on nickel release from simulated fixed orthodontic appliance. Nickel free brackets used in the study though claim to be absolutely nickel free but some amount of nickel was found in them also.