Magno Amanda Fahning Ferreira, Enoki Carla, Ito Izabel Yoko, Matsumoto Mirian Aiko Nakane, Faria Gisele, Nelson-Filho Paulo
Department of Pediatric Clinics, Preventive and Social Dentistry, Faculty of Dentistry, University of São Paulo, Ribeirão Preto, Brazil.
Am J Orthod Dentofacial Orthop. 2008 Apr;133(4 Suppl):S104-9. doi: 10.1016/j.ajodo.2006.04.054.
We investigated in vivo the contamination by Streptococcus mutans of Super Slick elastomeric rings (TP Orthodontics, LaPorte, Ind), manufactured with Metafasix technology (TP Orthodontics), using microbial culture and scanning electron microscopy (SEM).
Twenty patients undergoing fixed orthodontic appliance therapy were selected. Super Slick elastomeric rings (n = 160) were tied to brackets on the right maxillary premolars or molars and left mandibular premolars or molars. Conventional elastomeric rings (n = 160) were tied to brackets on the contralateral premolars or molars with the same split-mouth design. After a 15-day intraoral period, 75 elastomeric rings of each type were retrieved, submitted to microbiologic processing, and cultured in bacitracin sucrose broth-selective enrichment broth culture media. The number of S mutans colonies or biofilms on the surface of the electrometric rings was counted by using a stereomicroscope. Data were analyzed statistically with the Wilcoxon nonparametric test at the 5% significance level. Four representative rings of each type were chosen for SEM analysis.
Statistical analysis by the Wilcoxon nonparametric test showed that the Super Slick elastomeric rings had statistically significant greater S mutans contamination than the conventional elastomeric rings (P <.0001). No formation of S mutans colonies or biofilms was observed in the elastomeric rings removed directly from their original packages. SEM micrographs showed fissures on the surface of Super Slick elastomeric rings. No fissures were found on conventional elastomeric rings. When the microbiologic culture was positive, S mutans bacterial biofilm was observed on both types of ligatures.
There was no clinical evidence that Super Slick elastomeric rings are effective in reducing bacterial biofilm formation on their surfaces, and a recommendation for their use in orthodontic therapy for that purpose is not justifiable.
我们采用微生物培养和扫描电子显微镜（SEM）技术，在体内研究了采用Metafasix技术（TP Orthodontics公司）制造的Super Slick弹性环（TP Orthodontics公司，印第安纳州拉波特）被变形链球菌污染的情况。
选取20例接受固定正畸矫治器治疗的患者。将Super Slick弹性环（n = 160）系于右上颌前磨牙或磨牙以及左下颌前磨牙或磨牙的托槽上。采用相同的分口设计，将传统弹性环（n = 160）系于对侧前磨牙或磨牙的托槽上。经过15天的口内佩戴期后，每种类型的弹性环各取出75个，进行微生物处理，并在杆菌肽蔗糖肉汤选择性富集肉汤培养基中培养。使用体视显微镜计数电测环表面变形链球菌菌落或生物膜的数量。采用Wilcoxon非参数检验在5%显著性水平对数据进行统计学分析。每种类型选取4个代表性的环进行SEM分析。
Wilcoxon非参数检验的统计分析表明，Super Slick弹性环比传统弹性环的变形链球菌污染在统计学上显著更严重（P <.0001）。在直接从原始包装中取出的弹性环中未观察到变形链球菌菌落或生物膜的形成。SEM显微照片显示Super Slick弹性环表面有裂缝。在传统弹性环上未发现裂缝。当微生物培养呈阳性时，在两种类型的结扎丝上均观察到变形链球菌细菌生物膜。
没有临床证据表明Super Slick弹性环在减少其表面细菌生物膜形成方面有效，因此不适合推荐将其用于正畸治疗的这一目的。
