Mineral Trioxide Aggregate (MTA) Upregulates the Expression of <i>DMP1</i> in Direct Pulp Capping in the Rat Molar

• Main Authors: Maiko Yamada, Motohiko Nagayama, Yuka Miyamoto, Satoshi Kawano, Yoshiaki Takitani, Masashi Tanaka, Michiko Ehara, Juna Nakao, Takanaga Ochiai, Yoshihiro Shibukawa, Takakazu Yoshida
• Format: Article
• Language: English
• Published: MDPI AG 2021-08-01
• Series: Materials
• Subjects: mineral trioxide aggregate; direct pulp capping; mineral density; nestin; dentin matrix acidic phosphoprotein 1 (<i>DMP1</i>); dentin bridge
• Online Access: https://www.mdpi.com/1996-1944/14/16/4640

Mineral trioxide aggregate (MTA) is an alternative endodontic material that predicts conductive or inductive calcified tissue formation from immature pulp mesenchymal stem cells (IPMSCs). The purpose of this study was to investigate whether MTA could promote reparative odontoblast differentiation via IPMSCs in the early phase of regeneration and compare with calcium hydroxide (CH). Direct pulp capping using calcium hydroxide (CH), MTA, and MTA with platelet-rich plasma (MTA + PRP) was performed on maxillary first molars of 8-week-old male Wistar rats (<i>n</i> = 36). After 3, 7, or 14 days, the teeth were analyzed for mineral density (MD) and volume of MD (VMD) via micro-focusing computed tomography (µCT), nestin, dentin matrix acidic phosphoprotein 1 (<i>DMP1</i>) immunohistochemistry, and real-time PCR for <i>DMP1</i> mRNA expression. MTA stimulated the early phase differentiation of the IPMSCs into odontoblasts, with positive results for nestin and <i>DMP1</i> compared with CH. Moreover, MTA + PRP stimulated calcified granule and dentin bridge formation through calcium mineral deposition, following the induction of <i>DMP1</i> mRNA expression in IPMSCs. Our results suggested that the combination of MTA and PRP is an effective and clinically applicable method for activating endogenous dental pulp stem cells into odontoblasts in the early stages of pulp regeneration.