Clinical, Radiographic, and Histologic Outcome of Regenerative Endodontic Treatment in Human Teeth Using a Novel Collagen-hydroxyapatite Scaffold

INTRODUCTION

Histologic examination of teeth after regenerative endodontic treatment (RET) shows that the type, quality, and quantity of tissues formed in the root canal space are not predictable. The aim of this study was to examine clinically, radiographically, and histologically the outcome of RET in immature noninfected human teeth using SynOss Putty (Collagen Matrix Inc, Oakland, NJ) as a scaffold.

METHODS

Three pairs of maxillary/mandibular first premolars in 3 patients scheduled for extraction were included. Sensibility tests confirmed the presence of vital pulps. After informed consent, anesthesia, and rubber dam isolation, the pulps were removed. RET was performed using the following scaffolds: SynOss Putty + blood in both teeth in patient #1, SynOss Putty with or without blood in patient #2, and SynOss Putty + blood or blood only in patient #3. After a follow-up period of 2.5-7.5 months, the teeth were clinically and radiographically evaluated, extracted, and examined histologically.

RESULTS

Patients remained asymptomatic after treatment. Radiographic examination of the teeth showed signs of root development after treatment. In teeth treated with SynOss Putty + blood, histologic examination showed formation of intracanal mineralized tissue around the scaffold particles solidifying with newly formed cementumlike tissue on the dentinal walls. The tooth treated with SynOss Putty without blood showed the formation of a periapical lesion. The tooth treated with a blood clot only showed tissues of periodontal origin growing into the root canal space.

CONCLUSIONS

SynOss Putty + blood showed a predictable pattern of tissue formation and mineralization when used as a scaffold for RET in human immature noninfected teeth. The newly formed mineralized tissue solidifies with newly formed cementum on the dentinal walls.

Indications and case series of intentional replantation of teeth

This case series aims to comprehensively introduce intentional replantation with a focus on its indications and case selection in endodontics. In all represented cases, calcium enriched mixture (CEM) cement is used for root-end filling. This case series demonstrates twenty cases of IR and extraoral root-end resection and filling with CEM cement. All the selected teeth had a failed endodontic treatment and required surgical/nonsurgical endodontic (re)treatment or extraction. Subsequent to gentle tooth extraction, an appropriate root-end cavity was prepared and filled with CEM cement. Then the tooth was replanted; maximun procedure time was 15 min. A total of 18 cases (90%) were successful over a mean follow-up period of 15.5 months. It can be concluded that intentional replantation with careful case selection can have a high success rate over 2 years. Intentional replantation may be a suitable treatment option for both trained general practitioners and specialists provided that the extraction is simple and straightforward.

Subcutaneous tissue responses to three endodontic irrigants: a comparative study

INTRODUCTION

This study aimed to compare the subcutaneous tissue responses to MTAD (mixture of a tetracycline isomer, an acid, and a detergent), 17% EDTA, and 2.6% NaOCl.

MATERIALS AND METHODS

Thirty-six Wistar albino rats were used for this study. Test solutions were injected subcutaneously into predetermined areas on the animal dorsum. The rats were then randomly divided into three groups of twelve each and sacrificed at 2 hours, 2 days, and 2 weeks. The severity of inflammation induced by each irrigant at different time intervals was assessed histologically. The data were analyzed using Kruskal-Wallis and Friedman tests.

RESULTS

The difference in severity of inflammatory reactions induced by tested irrigants at the different time intervals was statically significant (P<0.05). There was no significant difference between the severity of inflammation induced by MTAD and 2.6% NaOCl at the various time intervals (P>0.05). Subcutaneous tissue responses to MTAD were not different from those observed in 17% EDTA specimens at 2-hour and 2-day intervals (P>0.05).

CONCLUSION

Under the conditions of this study, MTAD has the same toxicity as 2.6% NaOCl.