Histologic examination of teeth with necrotic pulps and periapical lesions treated with 2 scaffolds: an animal investigation.
BACKGROUND
Traditional pulp regeneration procedures that use a blood clot as a scaffold have produced histologic evidence of bone, cementum, and connective tissue growth within the root. Platelet-rich plasma (PRP) is a bioactive scaffold containing growth factors that enhance wound healing.


OBJECTIVE
The aim of this study was to histologically compare the tissues generated when PRP or a blood clot is placed into teeth with preexisting necrotic pulps and periapical lesions.


METHODS
Twenty-four canine teeth from 6 immature ferrets were used. Two ferrets served as positive controls. Sixteen experimental canine teeth from 4 ferrets were infected, debrided, treated with a triple antibiotic paste, and randomly distributed to the following groups: group 1 (blood clot/Gelfoam), group 2 (PRP), and group 3 (no scaffold). At 3 months, the ferrets were sacrificed, and the tissues were evaluated histologically. Data were analyzed by using the Fisher exact test (P < .05).


RESULTS
In 3 of 6 teeth in the PRP group, 2 of 6 teeth in the blood clot group, and 1 of 4 teeth in the no scaffold group, an ingrowth of hard tissues was observed in the apical third of the roots. When using PRP or a blood clot as a scaffold, we found significantly more apical narrowing and hard tissue deposition in comparison to not using a scaffold (P < .05).


CONCLUSIONS
The use of PRP or blood clots as scaffolds results in the ingrowth of bone-like, cementum-like, and connective tissue in the apical third of the roots at inconsistent rates.
Loma Linda University School of Dentistry, Loma Linda, California. Electronic address: mtorabinejad@llu.edu.
Mahmoud
M
Torabinejad
Loma Linda University School of Dentistry, Loma Linda, California.
Marites
M
Milan
Loma Linda University School of Dentistry, Loma Linda, California.
Shahrokh
S
Shabahang
Division of Anatomy, Loma Linda University School of Medicine, Loma Linda, California.
Kenneth R
KR
Wright
Loma Linda University School of Dentistry, Loma Linda, California.
Hadi
H
Faras
D000818:Animals; D000900:Anti-Bacterial Agents / Q000627:therapeutic use; D003782:Dental Pulp / Q000473:pathology; D003790:Dental Pulp Necrosis / Q000473:pathology* / Q000628:therapy*; D005289:Ferrets; D005781:Gelatin Sponge, Absorbable / Q000627:therapeutic use*; D006490:Hemostatics / Q000627:therapeutic use*; D010485:Periapical Periodontitis / Q000473:pathology* / Q000628:therapy*; D053657:Platelet-Rich Plasma; D012038:Regeneration; D054457:Tissue Scaffolds
D000900:Anti-Bacterial Agents; D006490:Hemostatics
Bone; cementum; dentin; ferret; regeneration; revascularization; revitalization