Bond Failure Rate of MBT Brackets Bonded with either Self-Etching Primer or Resin Modified Glass Ionomer vs Conventional Method – an in Vivo Study

摘要

Abstract Background . Self-etching primer and resin modified glass ionomer has been introduced to counter phosphoric etching disadvantages. Objectives . Evaluation of the bond failure rate of MBT stainless steel brackets bonded with either self etching primer SEP or resin modified glass ionomer RMGI in comparison with conventional methods CM. Material and Methods . 46 patients with complete permanent dentition were involved in this study. A total of 920 Gemini MBT? brackets (3M Unitek, Monrovia, Calif) were bonded using a split-mouth design. For each patient, four adhesives systems were used: self etching primer SEP (Transbond Plus?, 3M, Unitek, USA), resin-modified glass ionomer RMGI (Fuji Ortho? LC, GC Corp, Japan), light cure LC (Transpond XT?, 3M, Unitek, USA) and chemical cure CC (Unite?, 3M, Unitek, USA). All brackets were bonded by the same clinician. Only first-time bracket failures with tooth number and the remnant adhesive on the enamel were recorded through to 12th month of treatment and observation. Significant differences in bracket failure rate with regard to bonding procedure, patient sex, arch site, and tooth type were determined using the chi-square. The adhesive remnant index was used to determine the bond failure interface. Results . The bond failure rates were 7%, 15.7%, 7% and 6.5% for the SEP, RMGI, LC, CC respectively. Significant differences in failure rates were found between the groups. The maximum bond failure sites were at the enameladhesive interface in SEP and RMGI groups. Conclusion . The clinical study showed that Transbond Plus can be used effectively for bonding brackets, whereas using Fuji Ortho LC is not effective in clinical practice.