Westphalen G H, Menezes L M, Prá D, Garcia G G, Schmitt V M, Henriques J A P, Medina-Silva R
Departamento de Odontologia Preventiva, Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre, RS, Brasil.
Genet Mol Res. 2008;7(4):1259-66. doi: 10.4238/vol7-4gmr508.
Orthodontic appliances are usually made of stainless steel, which contains metals such as nickel, chromium and iron that have been associated with DNA damage. The aim of the present study was to determine the genetic toxicity associated with orthodontic fixed appliances in twenty healthy patients (16 +/- 2.5 years) undergoing orthodontic treatment (fixed appliances - basic composition: stainless steel alloy), using the micronucleus (MN) and comet (CA) assays in buccal cells. Primary DNA damage level, as assessed by the CA, was low either before the beginning (1.5 +/- 1.05 damage index - DI) or 10 days after the placement of the orthodontic appliance (2.5 +/- 3.08 DI) and did not change significantly between these time points (p= 0.0913). Conversely, there was a significant increase in MN frequency 30 days after the beginning of the treatment (p= 0.0236). In this study, the MN assay was shown to be more sensitive than the CA. Other investigations are necessary in order to assess the genotoxic potential of orthodontic fixed appliances associated with long-term studies concerning these effects in orthodontic patients.
正畸矫治器通常由不锈钢制成，其中含有镍、铬和铁等金属，这些金属与DNA损伤有关。本研究的目的是，通过对20名接受正畸治疗（固定矫治器——基本成分：不锈钢合金）的健康患者（16±2.5岁）颊细胞进行微核（MN）和彗星（CA）试验，来确定与正畸固定矫治器相关的遗传毒性。通过彗星试验评估的原发性DNA损伤水平，在正畸矫治器放置前（损伤指数——DI为1.5±1.05）或放置后10天（DI为2.5±3.08）均较低，且在这些时间点之间无显著变化（p = 0.0913）。相反，治疗开始30天后微核频率显著增加（p = 0.0236）。在本研究中，微核试验显示比彗星试验更敏感。为了评估正畸固定矫治器的遗传毒性潜力，有必要进行其他调查，这些调查涉及对正畸患者这些影响的长期研究。
