›› 2017, Vol. 8 ›› Issue (4): 177-181.

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The recharge methods of the novel calcium phosphate nanoparticle-containing orthodontic cement

  

  1. 1. Biomaterials & Tissue Engineering Division, Department of Endodontics, Periodontics and Prosthodontics, University of Maryland Dental School, Baltimore, MD 21201, USA
    2. Department of Dentistry, China Rehabilitation Research Center, Beijing, China
    3. Beijing Stomatological Hospital Capital Medical University
  • Received:2017-08-07 Revised:2017-12-07 Online:2017-12-25 Published:2017-12-26

Abstract: Objective: The objectives of this study were to develop the first NACP rechargeable orthodontic cement, and investigate the effects of recharge duration and frequency on ion re-release efficacy. Methods: The rechargeable cement consisted of pyromellitic glycerol dimethacrylate (PMGDM) and ethoxylated bisphenol-A dimethacrylate (EBPADMA). NACP were mixed into the resin at 40% by mass. Specimens were tested for orthodontic bracket shear bond strength (SBS) to enamel, Ca and P ion initial release was tested in pH 4 solution. After the ions were exhausted, the specimens were recharged in pH 7 solution and re-release in pH 4 solution again. The re-release of the ions were recorded. Results: The new orthodontic cement had SBS similar to commercial orthodontic cement without CaP release (p > 0.1). Specimens after one recharge treatment (e.g., 1 minute immersion in recharge solution repeating 3 times in one day, referred to as 1 min 3 times) had substantial release of Ca and P ions continuously for 14 d without further recharge. The ion re-release did not decrease with increasing the number of recharge/re-release cycles (p > 0.1). The ion re-release concentrations at 14 d versus various recharge treatments were: 1 min 3 times > 3 min 2 times > 1 min 2 times > 6 min 1 time > 3 min 1 time > 1 min 1 time. Conclusions: The present study developed the first orthodontic cement with Ca and P ion recharge and long-term release capability. This NACP rechargeable orthodontic cement is promising to inhibit enamel demineralization and WSL around orthodontic brackets.