J Korean Acad Conserv Dent.  2002 Jul;27(4):355-362. 10.5395/JKACD.2002.27.4.355.

Pulpal and periapical reaction to formocresol and depulpin(R) in the rat teeth

• Moon HI
• Kim SH
• Hwang YC
• Oh BJ
• Hwang IN
• Kim SH
• Jeong SW
• Youn C
• Oh WM

• KMID: 1987290
• DOI: http://doi.org/10.5395/JKACD.2002.27.4.355

Abstract

One fifth dilution of formocresol is usually used for pulpotomy of the primary teeth and emergency pulpotomy of the permanent teeth. However, the use of formaldehyde has been subjected to criticism because it may be absorbed into the blood stream and become distributed systemically, it may also alter the pulp tissue rendering it immunologically active, and have carcinogenic potential. Recently Depulpin(R)(VoCo., Germany) gains popularity as a devitalizing agent during root canal therapy in spite of high concentration of 49% paraformaldehyde because it facilitate devitalization of pulp and make root canal therapy easier. But there have been not enough publications about the reaction of pulp and periapical tissue caused by Depulpin. This study was performed to evaluate the histological changes in pulp and periapical tissue of rats after pulpotomy using formocresol and Depulpin and to elucidate the toxic effects of these agents. Thirty six Sprague-Dawley rats were anesthetized by intraperitoneal injection of ketamine. Maxillary first molar teeth were used for pulpotomy with formocresol and Depulpin. Rats were sacrificed after 2 days, 4 days, 1 week, 2 weeks, 3 weeks and 4 weeks respectively. Specimens were histologically observed by light microscope changes in pulp and periapical tissue. The obtained results were as follows. 1. Formocresol group A zone of fixed tissue, in which odontoblasts could clearly be defined, was present directly underneath the pulpotomy dressing in almost all teeth of this group. This was followed by an area of necrotic tissue which resembled dried out fibrous tissue with no cellular detail except some pyknotic nuclei. In the specimens of after 2 days, 4 days, 1 week, 2 weeks in which vital tissue was present, it was separated from the fibrous area by a zone of inflammation. In the specimens of after 3 weeks and after 4 weeks, inflammatory infiltrate was in the periodontal ligament adjacent to the apical foramina of the teeth. 2. Depulpin(R) group The area of necrotic tissue which had no cells and fibers, was present adjacent to the dressing. This was followed by dried out fibrous tissue with no cellular details except some pyknotic nuclei. A short stump of vital pulp with odontoblasts was present at the end of the canal after 2 days. Inflammatory infiltrate was in the periodontal ligament after 4 days and after 1week. Severe root resorption and necrosis of periapical tissue opposite the root resorption site were defined after 2 weeks and after 3 weeks. Periapical lesion which consist of necrotic tissue surrounded by a fibrous connective wall, was found after 4 weeks. The results indicated that Depulpin can cause more adverse reaction to the dental pulp and periapical tissue than formocresol, and further studies are needed for its clinical use with safety.

MeSH Terms

Animals
Bandages
Computer Communication Networks
Dental Pulp
Emergencies
Formaldehyde
Formocresols
Inflammation
Injections, Intraperitoneal
Ketamine
Light
Molar
Necrosis
Odontoblasts
Periapical Tissue
Periodontal Ligament
Polymers
Pulpotomy
Rats
Rats, Sprague-Dawley
Rivers
Root Canal Therapy
Root Resorption
Tooth
Tooth, Deciduous
Formaldehyde
Formocresols
Ketamine
Polymers

Figure

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  Fig. 1 Coronal pulp tissue of control group. Odontoblasts are columnar in shape. H & E stain, ×400.

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  Fig. 2 Apical pulp tissue and periapical tissue of control group. H & E stain, ×40.

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  Fig. 3 Coronal pulp tissue after 2 days of application of formocresol. H & E stain, ×100.

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  Fig. 4 Apical pulp tissue and periapical tissue after 2 days of application of Depulpin®. H & E stain, ×100.

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  Fig. 5 Apical pulp tissue and periapical tissue after 4 days of application of formocresol. No histologic change was observed in periodontal ligament. H & E stain, ×100.

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  Fig. 6 Pulp tissue after 4 days of application of formocresol. Dilatation of vessel was observed. H & E stain, ×400.

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  Fig. 7 Pulp tissue and periapical tissue after 4 days of application of Depulpin®. Periodontal ligament opposite the apical foramen was altered. H & E stain, ×100.

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  Fig. 8 Pulp tissue after 1 week of application of formocresol. Vital pulp tissue was observed in the apical area. H & E stain, ×40.

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  Fig. 9 Pulp tissue after 1 week of application of formocresol. No histologic change was observed in periodontal ligament. H & E stain, ×200.

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  Fig. 10 Pulp tissue and periapical tissue after 1 week of application of Depulpin®. H & E stain, ×100.

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  Fig. 11 Pulp tissue and periapical tissue after 2 weeks of application of formocresol. H & E stain, ×40.

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  Fig. 12 Apical pulp tissue and periapical tissue after 2 weeks of application of Depulpin®. Complete necrosis of pulp and resorption of alveolar socket bone was observed. H & E stain, ×100.

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  Fig. 13 Apical pulp tissue and periapical tissue after 3 weeks of application of formocresol. Inflammatory infiltrates were observed in periodontal ligament opposite the apical foramen. H & E stain, ×200.

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  Fig. 14 Pulp tissue and periapical tissue after 3 weeks of application of Depulpin®. Complete pulpal necrosis, root resorption and bone resorption were observed. H & E stain, ×40.

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  Fig. 15 Pulp tissue and periapical tissue after 3 weeks of application of Depulpin®. Complete pulpal necrosis, root resorption and bone resorption were observed. H & E stain, ×100.

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  Fig. 16 Pulp tissue and periapical tissue after 4 weeks of application of formocresol. Coronal pulp was fixed. Severe inflammatory infiltrations in the periapical area were shown. H & E stain, ×40.

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  Fig. 17 Pulp tissue and periapical tissue after 4 weeks of application of formocresol. H & E stain, ×100

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  Fig. 18 Pulp tissue and periapical tissue after fourth week application of Depulpin®. Complete pulpal necrosis, root resorption and bone resorption were observed. H & E stain, ×40.

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