Evaluation of Nickel Release in Blood and Periodontal Tissue with the Use of NiTi Wires, Bands and Brackets in Orthodontics – A Systematic Review

Abstract

BACKGROUND It is of outmost importance to know the effects of nickel on a cellular level. The objective of this systematic review was to analyse the factors affecting nickel release, the amount of nickel being released in commercially available NiTi wires and to also analyse the blood / periodontal evaluation after orthodontic treatment in conventional and nickel free brackets. METHODS For this systematic review, relevant articles were searched in PubMed, MedLine, Cochrane, EMBASE and Google Scholar databases, along with a complimentary manual search of all orthodontic journals from January 1980 till the year 2019 December. The study included in vitro and in vivo studies. 14 articles were included in this systematic review. RESULTS 160 articles were obtained initially. 41 were obtained by a manual search. 186 articles were excluded based on the inclusion criteria and 14 articles were found to be eligible. CONCLUSION This systematic review shows that nickel solution at a minimal concentration could damage human gingival fibroblast. As the carcinogenic effect of nickel has been already confirmed, other alloys that do not contain the heavy metal nickel can be used or standardization of the amount of nickel leach out from the appliance should be considered. KEY WORDS NiTi, Nickel Release, Periodontal Tissue or Periodontium, Cytotoxicity, Orthodontics