title: Influences of 4-meta/MMA-TBB adhesive resin on osteodentinogenesis of transplanted rabbit dental pulp in vivo: immunohistochemical and electronmicroscopic studies.
abstract: The purpose of this study was to investigate the influence of 4-META/MMA-TBB adhesive resin (4-META resin) on osteodentinogenesis of transplanted pulp in vivo. Dental pulp was obtained from the incisors of adult rabbits. 4-META resin was applied to the pulp tissue, and the pulp tissue with 4-META resin was autotransplanted beneath the renal capsule with the pulp side touching the kidney. Pulp tissue alone was also transplanted as a control. The animals were sacrificed at 3, 7, and 14 days after the experiment, and the specimens were examined morphologically. At 3 days, proliferation of mesenchymal cells was observed, and alkaline phosphatase activity (ALP) and osteocalcin were detected throughout the entire transplanted pulp area. In the experimental case, a thin, highly electron dense zone and a granular layer were observed. Under this layer, only a cell-membrane-like structure, a cell with an unclear nucleus, a nucleus alone, and an organelle-like structure could be seen. Furthermore, an exudative layer with many neutrophils was observed, and apoptotic-body-like structures were also found in some areas. On days 7 and 14 in the control group, osteoblast-like cells had proliferated, and osteodentin formation was initiated throughout the entire transplanted pulp area. In the experimental cases at 7 and 14 days, the entire transplanted area had become osteodentin except for a thin fibrous layer under the 4-META resin. These results suggested that the components of 4-META resin such as MMA and 4-MET (A), which guide the polymerization, might cause degeneration of, but not disturb, the wound healing of the pulp tissue.
authors.affiliation: Department of Pathology, Tokyo Dental College, Chiba, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Morohoshi
authors.forename: T
authors.initials: T
authors.lastname: Inoue
authors.forename: M
authors.initials: M
authors.lastname: Shimono
mesh_terms: D000180:Acrylic Resins / Q000494:pharmacology*; D000818:Animals; D003782:Dental Pulp / Q000187:drug effects* / Q000637:transplantation; D003809:Dentin, Secondary / Q000187:drug effects* / Q000254:growth & development*; D003810:Dentinogenesis / Q000187:drug effects; D008297:Male; D010012:Osteogenesis / Q000187:drug effects; D011817:Rabbits; D019279:Resin Cements / Q000494:pharmacology*
chemical_list: D000180:Acrylic Resins; D019279:Resin Cements; C031172:4-META resin