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BACKGROUND: Basic fibroblast growth factor (bFGF) can promote mitosis and chemotaxis of periodontal ligament fibroblasts (PDLCs), and help the generation of extracellular matrix and new blood capillaries. But it is easy to degrade,has short half-life, and metabolizes rapidly.OBJECTIVE: To evaluate the influence of bFGF/chitosan/polylactic acid scaffolds on PDLCs growth and proliferation.METHODS: Polylactic acid/chitosan composite scaffolds in different proportions (4:1, 3:2, 1:1, 2:3, 1:4) were prepared through freeze-drying method, to study their microstructure, porosity and mechanical strength and then choose the optimal ratio of chitosan/polylactic acid scaffold that was used to prepare the composite scaffolds which contained different concentrations (0, 0.1, 1, 10, 100 μg/L) of bFGF. (1) Cytotoxicity test: PDLCs were cultured with leaching liquid of polylactic acid/chitosan scaffolds which contained different concentrations (0, 0.1, 1, 10, 100 μg/L) of bFGF and DMEM culture medium respectively. The effects on cell proliferation were tested by MTT after 24, 48, 72 hours. Cell cycles were tested using flow cytometry at 5 days of culture. (2) Cytocompatibility test: PDLCs were co-cultured with the polylactic acid/chitosan scaffolds which contained different concentrations (0, 0.1, 1, 10, 100 μg/L) of bFGF. The number of PDLCs was counted at 1, 3, 5 and 7 days. The growing status of PDLCs on the scaffolds was observed by scanning electron microscope at 3 days of culture.RESULTS AND CONCLUSION: (1) The best mass ratio of polylactic acid and chitosan was 2:3 by test of porosity and mechanical strength. (2) The absorbance value of each group was increased over time. The absorbance values of 0.1, 1, 10, 100 μg/L bFGF groups were higher than that of the control group (0 μg/L bGFG), and the A value of 10 μg/L group was highest in all groups at 48 and 72 hours after co-culture (P < 0.05). (3) Cell percentages at G0/G1 phase of 0.1, 1, 10,100 μg/L bFGF groups were higher than that of the control group, and the percentage of 10 μg/L group was lowest in all groups (P < 0.05). Cell percentage at S phase and G2/M+S of 0.1, 1, 10, 100 μg/L bFGF groups were higher than that of the control group, and the percentage of 10 μg/L group was highest in all groups (P < 0.05). (4) The number of cells in each group was increased with time. The cell number in the 10 μg/L was most in all groups at 3 and 5 days of co-culture (P < 0.05). Observation of scanning electron microscopy showed that PDLCs adhered and grew well on the 10 μg/L bFGF/polylactic acid/chitosan composite scaffold when co-cultured for 3 days. Overall, these findings indicate that the bFGF/polylactic acid/chitosan composite scaffold contributes to PDLCs proliferation.
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Objective To investigate the long-term efficacy of calcium phosphate cement combined with bFGF in repairing pulp chamber perforation and to analyze the correlation between the diameter of the perforation and the curative effect.Methods 75 patients with pulp chamber perforation (82 teeth) were enrolled and divided into the observation group and the control group according to the repair material and method.A series of subgroups were also modeled according to the diameter of the perforation,which include the control group A (≤ 1.5 mm),control group B (1.6～3 mm) and control group C (＞3 mm),as well as the observation group A (≤ 1.5 mm),observation group B (1.6～3 rmm) and observation group C (＞3 mm).The observation group was treated with calcium phosphate cement combined with bFGF,and the control group was treated with calcium phosphate cement alone.Results The total effective rate of the observation group was 97.8％,which was significant higher than 80.6％ in the control group (P＜0.05).The cure rate of the observation group A was 100％,which was significant higher than 73.3％ in the observation group B and 41.7％ in the observation group C (all P＜0.05).The total effective rates of the observation group A and B were significantly higher than 91.7％ in the observation group C (all P＜0.05).The cure rate of the control group A was 92.9％,which was significant higher than 60.0％ in the control group B and 25.0％ in the control group C (all P＜0.05).The total effective rates of the control group A (100％) and B (90.0％) were significantly higher than 91.7％ in the control group C (all P＜0.05).Conclusions Calcium phosphate cement combined with bFGF in repairing the pulp chamber perforation was significantly better than calcium phosphate cement alone.The cure rate of perforation repairing is closely related to the perforation size.The perforation with small diameter may achieve a better repairing effect.
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BACKGROUND: The root canal filling materials available have different degrees of noxious stimulation to periapical tissue and cannot induce growth and regeneration of bone at the periapical region. Moreover, the operation of canal filling is not easily controlled.OBJECTIVE: To investigate biocompatibility and osteoconductivity between periapical tissue and compound coral paste after root canal filling.DESIGN: Controlled observation.SETTING: Department of Stomatology in the Renmin Hospital of Wuhan University.MATERIALS: The experiment was carried out in the Key Laboratory for Oral Biomedical Engineering by the State Ministry of Education, School of Stomatology in Wuhan University from September 2002 to January 2006. Eight adult female mongrel dogs, weighed 15 kg, were offered by the Wuhan General Hospital of Guangzhou Military Area Command of Chinese PLA (SYXK-2003-0007). Each dog contained 32 root canals, and totally 256 root canals were utilized in this study.METHODS: Experimental animals underwent general anesthesia by the intravenous injection of sodium pentobarbital (30 mg/kg), then tracheal intubation was utilized for the root canal filling, and the canals were randomly distributed into two groups: experimental group (n=128) with compound coral paste (coral 40 g and iodoform 8 g, offered by the Key Laboratory for Oral Biomedical Engineering by the State Ministry of Education, School of Stomatology in Wuhan University); control group (n=128) with gutta-percha point+zinc oxide-eugenol sealer. One animal was sacrificed by anesthetic overdose at 2, 4, 12 and 24 weeks after root canal filling, dental film by X-ray and light microscope were used for the examination.MAIN OUTCOME MEASURES: ①Periapical inflammation: Cells were counted in a high power field, and three levels were defined as mild (＜100 cells/mm2), moderate (100-200 cells/mm2) and severe (＞200 cells/mm2).②destruction and regeneration of periapical tissues.③bone substitute of compound coral paste in periapical regions.RESULTS: Eight mongrel dogs were all involved in the result analysis.①Periapical shadow by X-ray film: Distinct shadow at root apex area can not be observed in the experimental group at each stage. While two cases appeared the root apex shadow in the control group at 12 and 24 weeks, respectively.②Histopathological observation: At 2 weeks after root filling,inflammatory cell infiltration was observed in each group, which was dominantly neutrocyte. There was a mild inflammation in experimental group and a moderate inflammation in control group. Four weeks after root filling, there were focal inflammatory cells infiltrated around the coral particles in the experimental group, but in the control group there were a great deal of inflammatory cells in periapical tissue. Twelve weeks after root filling, in experimental group, there was no inflammatory cell infiltration was observed, the deposition of bone combined tightly with coral particles was detected, and apical foramen became smaller;, but in the control group, there were still inflammatory cells circumvohiting the gutta-percha point. After 24 weeks, coral particles was not observed at the root filling region in the experimental group, and they were replaced by a great deal deposition of bones, root foramens were sealed completely and grew into root canal wall. Root apex was coated with fibrous tissue in the control group.CONCLUSION: This compound coral paste shows good compatibility after filling, promotes the osteoconductivity, and seals the root foremen, so it can be used as a root canal filling material.
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OBJECTIVE:To investigate osteogenic and chondrogenic differentiation of adipose-derived stem cells following a short time induction with bone morphogenetic protein 2(BMP-2) or BMP-7.METHODS:The subcutaneous adipose tissue was obtained from adult New Zealand rabbits under aseptic condition,and cultured in vitro with collagenase digestion.All cells were divided into 3 groups:in the BMP-2 group,cells were cultured with medium containing 0.1 g/L vitamin C,10 mmol/L?-sodium glycerophosphate and 10?g/L BMP-2 for 10 minutes,followed by 4-14 days inoculation with density of 18?104 cells per pore.In the BMP-7 group,cells were cultured with BMP-7 with the same methods as BMP-2 group.The cells were cultured with simple culture medium in the control group.RESULTS:Compared to the control group,the number of adipose-derived stem cells,protein level and ALalkaline phosphatase(ALP) activity of BMP-2 and BMP-7 groups was up-regulated 1.78-1.79,1.15-1.95,and 32-40 times,respectively.At days 4 after a 15 minutes induction,the runx-2 gene expression,osteopontin gene,and biglycan gene were increased 1.9,2.2 and 1.3-1.7 folds than that of the control group.Meantime,only the biglycan gene expression was increased 1.3-1.7 folds in the BMP-7 group,the runx-2 gene expression,osteopontin gene was not changed.At day 14 after a 15 minutes induction,there was no alter of runx-2,osteopontin,biglycan,as well as aggrecan gene expression in the BMP-2 group;while down-regulated runx-2,osteopontin,biglycan 1.8,5.0 and 1.7 folds,with increased aggrecan gene in the BMP-7 group.CONCLUSION:Following a short time induction,BMP-2 can stimulate runx-2 and osteogenic expression at 4 days after re-culture,whereas BMP-7 down-regulate genes expression at days 14,yet down-regulate aggrecan mRNA expression.
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BACKGROUND: The direct ratio is formed between the size of osseous defect around implant and the required time of complete repair. It is viewed that bone implantation is suggested if osseous defect is larger than 1 mm, which benefits the bone regeneration and early fixation of implant.OBJECTIVE: To compare the effects between coralline granules and hydroxyapatite (HA) during union after immediate implantation.DESIGN: Group observation and controlled experiment was designed.SETTING: Department of Stomatology Renmin Hospital of Wuhan University.MATERIALS: HA coated implant, HA granule, coralline granule and 3adult mongrel dogs.METHODS: The experiment was performed in Department of Stomatology, Renmin Hospital of Wuhan University from August 2002 to April 2003.Under anesthesia, 6 foramens were drilled on femurs of 3 dogs (3 foramens on each side) to result in osseous defect. Coralline granules were embedded in the osseous defect around the implant in all of proximal ends (coralline granule group, CG group), HA granules were embedded in the osseous defect around the implant in all of distal ends (HA group) and nothing was embedded in the defect around the implant in the center (the control). One dog was sacrificed under anesthesia on the 2nd, 3rd and 4th months after operation successively and the samples were collected from the implanted section in each group for X-ray examination and scanning electronic microscopic observation.MAIN OUTCOME MEASURES: X-ray examination on implanted sections and scanning electronic microscopic observation on samples in each the 4th month, it was observed that implants and osseous tissue were closely integrated in CG group and HA group and there was still partial osseous on samples in each group: on the 4th month, it was discovered that the regenerated osseous tissue was matured completely in CG group and few coralline granule residue was left. In HA group, the regenerated osseous tissue was matured completely, but there was still a large amount of HA granules left and the granules had not been absorbed obviously. In the control group, the space appeared partially in the implanted cervical region.CONCLUSION: The implantation of artificial bone is suggested if the osseous defect around immediate implant is larger than 1 mm. As the implanting materials, coralline granules and HA granules act on the most advantageous guide activity. Coralline granules can be degraded and substituted with osseous tissue,but HA granules cannot be absorbed, which affects osseous reconstruction.