title: Histologic comparison between platelet-rich plasma and blood clot in regenerative endodontic treatment: an animal study.
abstract: BACKGROUND
  In regenerative endodontic treatment (RET) for immature permanent tooth, better treatment results could be obtained by applying platelet-rich plasma (PRP) as the scaffold rather than the blood clot. The goal of this study was to compare the histologic differences between using PRP and blood clot in RET.
  
  
  METHODS
  Three 6-month-old beagles each carrying 9 premolars with double root canals were randomly assigned to the PRP group, blood clot group, or negative control group. All experimental teeth suffered apical periodontitis, and RET was performed. In the blood clot group, bleeding was induced from the periapical tissues to fill the canal space. In the PRP group, autologous PRP was injected into each root canal. The animals were sacrificed 3 months later. Histologic sections were stained with hematoxylin-eosin. Statistical analysis was performed by the Fisher exact test, with the significance set at 0.05.
  
  
  RESULTS
  With the ingrowth of cellular cementumlike tissues, the canal wall was thickened, and the apical apex was closed in both the PRP and blood clot groups. Cementocytelike cells were present in the newly formed tissues. Meanwhile, no statistical difference was found in both experimental groups for the average percentage of apical closure, new tissue formation, and pulplike tissue formation. Noticeably, a large number of inflammatory cells were present in some root canals in both groups although the postoperative radiograph revealed the disappearance of periapical radiolucency.
  
  
  CONCLUSIONS
  PRP application could be an option for clinical cases in which little or no bleeding were found when irritating the apical tissue during RET.
authors.affiliation: Department of Pediatric Dentistry, School of Stomatology, China Medical University, Shenyang, China.
authors.forename: Dan-Dan
authors.initials: DD
authors.lastname: Zhang
authors.affiliation: Department of Pediatric Dentistry, School of Stomatology, China Medical University, Shenyang, China; Laboratory of Pediatric Dentistry, Liaoning Stomatology Research Institute, Shenyang, China. Electronic address: chenxu_cmu@sina.com.
authors.forename: Xu
authors.initials: X
authors.lastname: Chen
authors.affiliation: Department of Pediatric Dentistry, School of Stomatology, China Medical University, Shenyang, China; Laboratory of Pediatric Dentistry, Liaoning Stomatology Research Institute, Shenyang, China.
authors.forename: Zhi-Fan
authors.initials: ZF
authors.lastname: Bao
authors.affiliation: Department of Pediatric Dentistry, School of Stomatology, China Medical University, Shenyang, China.
authors.forename: Min
authors.initials: M
authors.lastname: Chen
authors.affiliation: Department of Pediatric Dentistry, School of Stomatology, China Medical University, Shenyang, China; Laboratory of Pediatric Dentistry, Liaoning Stomatology Research Institute, Shenyang, China.
authors.forename: Zhen-Jiang
authors.initials: ZJ
authors.lastname: Ding
authors.affiliation: Department of Oral Pathology, School of Stomatology, China Medical University, Shenyang, China.
authors.forename: Ming
authors.initials: M
authors.lastname: Zhong
mesh_terms: D017607:Aluminum Compounds / Q000627:therapeutic use; D000818:Animals; D056624:Apexification / Q000379:methods*; D001777:Blood Coagulation / Q000502:physiology*; D017610:Calcium Compounds / Q000627:therapeutic use; D025021:Cementogenesis / Q000502:physiology; D002939:Ciprofloxacin / Q000627:therapeutic use; D003739:Dental Cementum / Q000033:anatomy & histology / Q000166:cytology; D003782:Dental Pulp / Q000033:anatomy & histology / Q000502:physiology; D003786:Dental Pulp Cavity / Q000033:anatomy & histology*; D004285:Dogs; D004338:Drug Combinations; D008795:Metronidazole / Q000627:therapeutic use; D008911:Minocycline / Q000627:therapeutic use; D010087:Oxides / Q000627:therapeutic use; D010485:Periapical Periodontitis / Q000628:therapy; D053657:Platelet-Rich Plasma / Q000502:physiology*; D016300:Radiography, Bitewing; D011897:Random Allocation; D012038:Regeneration / Q000502:physiology; D012387:Root Canal Filling Materials / Q000627:therapeutic use; D012388:Root Canal Irrigants / Q000627:therapeutic use; D018915:Root Canal Preparation / Q000379:methods; D017640:Silicates / Q000627:therapeutic use; D019227:Tooth Apex / Q000033:anatomy & histology*; D014945:Wound Healing / Q000502:physiology
chemical_list: D017607:Aluminum Compounds; D017610:Calcium Compounds; D004338:Drug Combinations; D010087:Oxides; D012387:Root Canal Filling Materials; D012388:Root Canal Irrigants; D017640:Silicates; C086631:mineral trioxide aggregate; D008795:Metronidazole; D002939:Ciprofloxacin; D008911:Minocycline
keywords: Animal study; blood clot; immature permanent tooth; platelet-rich plasma; regenerative endodontic treatment