RESUMEN
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 (n = 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 (DMP1) immunohistochemistry, and real-time PCR for DMP1 mRNA expression. MTA stimulated the early phase differentiation of the IPMSCs into odontoblasts, with positive results for nestin and DMP1 compared with CH. Moreover, MTA + PRP stimulated calcified granule and dentin bridge formation through calcium mineral deposition, following the induction of DMP1 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.
RESUMEN
Although bisphosphonates are widely used to treat conditions such as osteoporosis, they may cause osteonecrosis of the jaw. We treated a patient with no history of tooth extraction or other surgical treatment who developed medication-related osteonecrosis of the jaw (MRONJ) with secondary pulpal disease. A 79-year-old woman presented with purulent discharge from the gum at the incisor region. She had been using bisphosphonates for 9 years. Tooth #6 had undertaken root canal treatment at a general practice. All teeth other than tooth #6 reacted to electric pulp testing. Computed tomographic imaging revealed signs suggestive of necrotic bone, and MRONJ was diagnosed. Teeth #7 and #8, which had initially exhibited vital reactions, also subsequently ceased to react to thermal and electric pulp testing. Root canal treatment was performed on teeth #6-8, and their condition was monitored. Computed tomographic imaging at 9 months after the first presentation revealed that the bone defect had greatly enlarged with separation of the necrotic bone; therefore, excision of the necrotic bone and curettage were performed in the department of oral and maxillofacial surgery. The loss of pulp reaction in teeth that had exhibited a vital reaction at the first presentation was considered to indicate that teeth #6-8 had developed dental pulp pathosis as a result of MRONJ.