title: Novel microinjector for carrying bone substitutes for bone regeneration in periodontal diseases.
abstract: OBJECTIVE
  Traditionally, guide bone regeneration (GBR) was a widely used method for repairing bone lost from periodontal disease. There were some disadvantages associated with the GBR method, such as the need for a stable barrier membrane and a new creative cavity during the surgical process. To address these disadvantages, the purpose of this study was to evaluate a novel microinjector developed for dental applications. The microinjector was designed to carry bone graft substitutes to restore bone defects for bone regeneration in periodontal diseases. The device would be used to replace the GBR method.
  
  
  METHODS
  In this study, the injected force and ejected volume of substitutes (including air, water, and ethanol) were defined by Hooke's law (n = 3). The optimal particle size of bone graft substitutes was determined by measuring the recycle ratio of bone graft substitutes from the microinjector (n = 3). Furthermore, a novel agarose gel model was used to evaluate the feasibility of the microinjector.
  
  
  RESULTS
  The current study found that the injected force was less than 0.4 N for obtaining the ejected volume of approximately 2 mL, and when the particle size of tricalcium phosphate (TCP) was smaller than 0.5 mm, 80% TCP could be ejected from the microinjector. Furthermore, by using an agarose model to simulate the periodontal soft tissue, it was also found that bone graft substitutes could be easily injected into the gel.
  
  
  CONCLUSIONS
  The results confirmed the feasibility of this novel microinjector for dental applications to carry bone graft substitutes for the restoration of bone defects of periodontal disease.
authors.affiliation: Institute of Biomedical Engineering, College of Medicine and College of Engineering, National Taiwan University, Taipei 100, Taiwan, ROC; Postgraduate Institute of Clinical Dentistry, School of Dentistry, National Taiwan University, Taipei 100, Taiwan, ROC.
authors.forename: Hsiao-Cheng
authors.initials: HC
authors.lastname: Tsai
authors.affiliation: Institute of Biomedical Engineering, College of Medicine and College of Engineering, National Taiwan University, Taipei 100, Taiwan, ROC.
authors.forename: Yi-Chen
authors.initials: YC
authors.lastname: Li
authors.affiliation: Institute of Biomedical Engineering, College of Medicine and College of Engineering, National Taiwan University, Taipei 100, Taiwan, ROC. Electronic address: thyoung@ntu.edu.tw.
authors.forename: Tai-Horng
authors.initials: TH
authors.lastname: Young
authors.affiliation: Postgraduate Institute of Clinical Dentistry, School of Dentistry, National Taiwan University, Taipei 100, Taiwan, ROC. Electronic address: minhueychen@ntu.edu.tw.
authors.forename: Min-Huey
authors.initials: MH
authors.lastname: Chen
mesh_terms: D001861:Bone Regeneration; D018786:Bone Substitutes / Q000008:administration & dosage*; D016025:Bone Transplantation / Q000295:instrumentation*; D002130:Calcium Phosphates / Q000008:administration & dosage*; D006801:Humans; D009339:Needles; D010510:Periodontal Diseases / Q000601:surgery
chemical_list: D018786:Bone Substitutes; D002130:Calcium Phosphates; C018392:tricalcium phosphate
keywords: bone defect; microinjector; periodontal disease