Basic Research
Histologic Examination of Teeth with Necrotic Pulps and Periapical Lesions Treated with 2 Scaffolds: An Animal Investigation

https://doi.org/10.1016/j.joen.2015.01.026Get rights and content

Highlights

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

  • Using scaffolds of PRP or blood clots resulted in more apical narrowing and hard tissue deposition versus when not using a scaffold.

  • 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.

Abstract

Introduction

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.

Aim

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.

Section snippets

Methods

All animal experiments were performed in accordance with protocols approved by the Loma Linda University Animal Research Committee. Six 70-day-old male ferrets with immature canine teeth were used in this experiment. Two animals provided the positive controls, and the 4 remaining ferrets provided the experimental teeth. A total of 16 experimental and 8 positive control teeth were used in this study. Preoperative radiographs were obtained to confirm the presence of an open apex and the absence

Results

Clinical evaluation revealed that the teeth in all groups had no evidence of swelling, mobility, or sinus tracts, and all restorations were intact.

In all of the positive control teeth, normal development was noted. The canals were filled with normal pulp tissue lined with odontoblasts subjacent to the predentin (Fig. 1A). Normal physiological dentinal thickening of the root and apical closure were observed along with the presence of multiple apical deltas (normal apex anatomy in ferret teeth).

Discussion

The histologic regeneration of pulp-like tissues has been shown in previous studies 4, 5, 19. Ideally, the ultimate goal of regenerative endodontics is observation of true, functional pulp tissue with peripheral odontoblasts, which has been found in a de novo study (19). This study with the ferret animal model resulted in the development of hard tissue similar to the morphology of bone and cementum at an unpredictable rate. The studies mentioned above were on human subjects, and the de novo

Acknowledgments

The authors thank Dr George Saukel from the Department of Surgical Pathology at the LLU Medical Center for assisting with the photography of histologic specimens. They also thank Dr Udochukwu Oyoyo for help with the statistical analysis of this investigation.

The authors thank the AAE Foundation for partial support of this investigation.

The authors deny any conflicts of interest related to this study.

References (39)

Cited by (60)

View all citing articles on Scopus
View full text