acid-phosphatase and Dentin--Secondary

The aim of this study was to analyze the contribution of nonresident progenitor/stem cells and hematopoietic cells to reparative dentinogenesis.. Parabiosis was established between C57BL/6-TgN(ACTbEGFP)10sb/J transgenic mice (GFP+) and C57BL/6 wild-type mice (GFP-) to ensure blood cross-circulation between animals. Reparative dentinogenesis was stimulated by pulp exposures and capping on the first maxillary molar in the GFP- mice. Histologic sections of injured molars from GFP- mice were analyzed by epifluorescence microscopy to examine the contributions of GFP+ cells (nonresident progenitor cells and hematopoietic cells originating from GFP+ mice) to reparative dentinogenesis.. GFP+ cells were detected in close association with reparative dentin formed at the site of pulp exposure in the maxillary first molars of the GFP- mice.. The present study suggests the participation of the nonresident progenitor cells and hematopoietic cells in reparative dentinogenesis.

Topics: Acid Phosphatase; Aluminum Compounds; Animals; Biomarkers; Calcium Compounds; Composite Resins; Cross Circulation; Dental Materials; Dental Pulp Capping; Dental Pulp Exposure; Dentin, Secondary; Dentinogenesis; Drug Combinations; Flow Cytometry; Fluorescent Dyes; Green Fluorescent Proteins; Hematopoietic Stem Cells; Isoenzymes; Mice; Mice, Inbred C57BL; Mice, Transgenic; Microscopy, Fluorescence; Models, Animal; Molar; Odontoblasts; Oxides; Parabiosis; Pulp Capping and Pulpectomy Agents; Resin Cements; Silicates; Silicon Dioxide; Stem Cells; Tartrate-Resistant Acid Phosphatase; Zirconium

Administration of actinomycin D at a dose level of 0.375 microgram/g resulted in the selective disruption of developing odontoblasts at a critical stage of morphogenesis. A dentin niche was formed which was later repaired by cellular reparative dentin. The cellular changes which resulted in dentin niche formation were studied histologically and ultrastructurally in serial longitudinal and transverse sections from tissues obtained 10 h to 80 h following injection of the drug. Five stages were identified: initial destruction (10-20 h), rapid destruction (30-40 h), debris removal (50-60 h), proliferation (60-80 h) and matrix deposition (post 80 h). The cellular changes found in the dental papilla were considerably different from those found in inflammation, resolution and repair of fibrous connective tissue. These early stages were dominated by apoptosis and heterophagy, and after 80 h by disordered dentin matrix formation. The three-dimensional morphology of the defect was reconstructed from serial sections. The shape of the niche was the result of interference by actinomycin D in the patterns of proliferation and migration of the cells in the apical region of the rat incisor tooth.

Topics: Acid Phosphatase; Animals; Apoptosis; Cell Movement; Dactinomycin; Dental Papilla; Dentin; Dentin, Secondary; Dentinogenesis; Immunoenzyme Techniques; Incisor; Lysosomes; Male; Odontoblasts; Phagosomes; Rats; Rats, Wistar; Time Factors

Topics: Acid Phosphatase; Alkaline Phosphatase; Animals; Dental Pulp Exposure; Dentin, Secondary; Molar; Rats

Topics: Acid Phosphatase; Albumins; Alkaline Phosphatase; Biological Products; Bone Regeneration; Calcium Hydroxide; Chondroitin; Collagen; Dental Pulp Capping; Dental Pulp Exposure; Dentin, Secondary; Humans; In Vitro Techniques; Odontoblasts; Root Canal Therapy; Sulfates