Extension and dentin differentiation potential of dental pulp stem cells from human deciduous teeth on the stiff matrix surface / 中国组织工程研究

BACKGROUND: Dental pulp stem cells can differentiate into dentin under appropriate induction conditions, which are important seed cells i n dental tissue engineering. However, the commonly used inducers are chemical agents, which are not available for in vivo application. Mesenchymal stem cells can differentiate with the material hardness, and the physical property-induced cell differentiation is little reported. OBJECTIVE: To observe the extension characteristics and dentin differentiation potential of dental pulp stem cells from human deciduous teeth on the stiff matrix surface. METHODS: Dental pulp stem cells from naturally shed deciduous teeth were isolated, cultured and identified. Four solid gel matrixes with elasticity modulus of (9.12±0.94), (27.18±3.55), (59.37±4.05) and (86.45±5.33) kPa were made using low melting point agarose. The extension ability of passage 4 dental pulp stem cells on the surface of the above solid matrixes was detected by two-dimensional clone formation and cell scratch tests. The protein expression levels of dentin matrix protein-1, dentin phosphoprotein and dentin sialoprotein were detected by western blot assay. RESULTS AND CONCLUSION: Dental pulp stem cells from human deciduous teeth seeded on the gel matrix with extremely low and low hardness almost existed as cell clones with neat edges, and cell spreading and extension were rare. When seeded on the gel matrix with moderate and high hardness, the cloned edge of deciduous dental pulp stem cells spread and extended obviously. The cell body became large and the cell edge extended significantly. The cell scratch test revealed the similar phenomenon. When seeded on the gel matrix with moderate and high hardness, dental pulp stem cells from human deciduous teeth exhibited high expression levels of of dentin matrix protein-1, dentin phosphoprotein and dentin sialoprotein. In summary, with the increase of matrix hardness, the abilities of extension and differentiation into dentin of dental pulp stem cells from human deciduous teeth are increased gradually, which provides a method for dental tissue engineering.

Evaluation of reparative dentin formation of ProRoot MTA, Biodentine and BioAggregate using micro-CT and immunohistochemistry

OBJECTIVES: The purpose of this study was to assess the ability of two new calcium silicate-based pulp-capping materials (Biodentine and BioAggregate) to induce healing in a rat pulp injury model and to compare them with mineral trioxide aggregate (MTA). MATERIALS AND METHODS: Eighteen rats were anesthetized, cavities were prepared and the pulp was capped with either of ProRoot MTA, Biodentine, or BioAggregate. The specimens were scanned using a high-resolution micro-computed tomography (micro-CT) system and were prepared and evaluated histologically and immunohistochemically using dentin sialoprotein (DSP). RESULTS: On micro-CT analysis, the ProRoot MTA and Biodentine groups showed significantly thicker hard tissue formation (p < 0.05). On H&E staining, ProRoot MTA showed complete dentin bridge formation with normal pulpal histology. In the Biodentine and BioAggregate groups, a thick, homogeneous hard tissue barrier was observed. The ProRoot MTA specimens showed strong immunopositive reaction for DSP. CONCLUSIONS: Our results suggest that calcium silicate-based pulp-capping materials induce favorable effects on reparative processes during vital pulp therapy and that both Biodentine and BioAggregate could be considered as alternatives to ProRoot MTA.

Evaluation of reparative dentin formation of ProRoot MTA, Biodentine and BioAggregate using micro-CT and immunohistochemistry

OBJECTIVES: The purpose of this study was to assess the ability of two new calcium silicate-based pulp-capping materials (Biodentine and BioAggregate) to induce healing in a rat pulp injury model and to compare them with mineral trioxide aggregate (MTA). MATERIALS AND METHODS: Eighteen rats were anesthetized, cavities were prepared and the pulp was capped with either of ProRoot MTA, Biodentine, or BioAggregate. The specimens were scanned using a high-resolution micro-computed tomography (micro-CT) system and were prepared and evaluated histologically and immunohistochemically using dentin sialoprotein (DSP). RESULTS: On micro-CT analysis, the ProRoot MTA and Biodentine groups showed significantly thicker hard tissue formation (p < 0.05). On H&E staining, ProRoot MTA showed complete dentin bridge formation with normal pulpal histology. In the Biodentine and BioAggregate groups, a thick, homogeneous hard tissue barrier was observed. The ProRoot MTA specimens showed strong immunopositive reaction for DSP. CONCLUSIONS: Our results suggest that calcium silicate-based pulp-capping materials induce favorable effects on reparative processes during vital pulp therapy and that both Biodentine and BioAggregate could be considered as alternatives to ProRoot MTA.

Influence of Root resorption caused by orthodontic tooth movement on GCF DSPP, DSP expression / 中国基层医药

ObjectiveTo investigate the influence of root resorption caused by orthodontic tooth movement,on gingival crevicular fluid (GCF) dentin sialophosphoprotein,DSPP,dentin sialoprotein,DSP expression.Methods67 patients admitted to hospital orthodontic patients as the clinical study,and according to different power values were divided into experimental group and control group,which had great value for the experimental group(300g) group and control group value for the normal force(30g) group,the two groups one week 12 weeks of its GCF DSPP,DSP expression were detected.ResultsIn the observation group DSPP,DSP expression was significantly higher than that in the control group,two groups of patients were in 7～9 weeks demonstrated increased,the observation group were(232 315 ±5437) gray,(487 876 ± 4374),(287 673 ± 5642),(212 147±2346) control group of gray scale,( 176 565 ±5327),(134 323 ± 2315 );and in 10 weeks after the reduction,the observation group 10 weeks and 11 weeks,(394 532 ± 4326),(287 674 ± 3235 ) ;the control group were( 87 876 ± 4323 ),(76 534 ± 3564),10 week 11 weeks were significantly reduced.ConclusionIn the process of root resorption in GCF DSPP,DSP changes in expression levels may be earlier than the X-ray results and the clinical manifestations,as it may cause root resorption of orthodontic tooth movement in the early detection of a target.

Histological evaluation of direct pulp capping with DSP-derived synthetic peptide in beagle dog / 대한치과보존학회지

The purpose of this study was to investigate the pulpal response to direct pulp capping with dentin sialoprotein (DSP)-derived synthetic peptide in teeth of dogs, and to compare its efficacy to capping substances Ca(OH)2 and white mineral trioxide aggregate (WMTA). A total of 72 teeth of 6 healthy male beagle dogs were used. The mechanically exposed pulps were capped with one of the following: (1) DSP-derived synthetic peptide (PEP group); (2) Ca(OH)2 (CH group); (3) a mixture paste of peptide and Ca(OH)2 (PEP+CH group); or (4) white MTA (WMTA group). The access cavity was restored with a reinforced glass ionomer cement. Two dogs were sacrificed at each pre-determined intervals (2 weeks, 1 month, and 3 months). After the specimens were prepared for standard histological processing, sections were stained with hematoxylin and eosin. Under a light microscope, inflammatory response and hard tissue formation were evaluated in a blind manner by 2 observers. In the PEP group, only 3 of 17 specimens showed hard tissue formation, indication that the DSP-derived synthetic peptide did not induce proper healing of the pulp. Compared with the CH group, the PEP group demonstrated an increased inflammatory response and poor hard tissue formation. The CH and WMTA groups showed similar results for direct pulp capping in mechanically exposed teeth of dogs.

Expression of DSP,DMP1,CBFA1,BMP2 in rat dental pulp stem cells / 实用口腔医学杂志

Objective:To examine the expression pattern of DSP,DMP1,CBFA1,BMP2 in rat dental pulp stem cells(RDPSCs).Methods:Immunohistochemical staining was carried out using antibodies against DSP,DMP1, CBFA1 ,BMP2 in rat dental pulp stem cells. Mineralization was induced in the RDPSCs and expression of DSP and DMP1 was measured after induction.Results:CBFA1 and BMP2 were positive in RDPSCs. Only a few RDPSCs were stained positive for DMP1. DSP expression was observed in the minority of these cells. However, the majority of the RDPSCs were found strongly positive for DSP and DMP1 after mineralization induction.Conclusion:Positive expression of CBFA1 and BMP2 indicates the premature nature of RDPSCs. The dentin-specific expression of DSP demonstrates that the RDPSCs can differentiate along odontoblastic lineage.

Nucleotide polymorphisms analysis of dentin sialoprotein / 实用口腔医学杂志

Objective:To analyse the nucleotide polymorphism of dentin sialoprotein(DSP) coden region in Chinese people. Methods:The DSP segments were amplified by PCR;single-stranded conformation polymorphism(SSCP) and DNA sequencing were employed to detect the nucleotide polymorphisms in DSP coden region. Results:Three single nucleotide polymorphisms(SNP) were found in DSP coden region,two were same sense SNPs resulting in no change of amino acid product,and one was missense SNP resulting in change of asparagine and aspartic acid. Conclusion:There are some SNPs existing in DSP coden region in Chinese people.