The effects of BMP and TGF-beta on the wound healing of the pulp

本研究的目的是探讨骨形态发生蛋白（BMPs）和转化生长因子- β (tgf - β)对牙髓伤口愈合的影响。首先，从大鼠胫骨中提取含有BMP和tgf - β的水不溶性部分与生理盐水混合。这种混合物被放置在牙髓室的近中部分，覆盖上颌第一磨牙近中根的根状牙髓。在放置上述混合物后的第一周，在髓根组织的不同区域，如近尖端、截肢部位和中央区域，可见炎症和纤维组织的形成。第2周，在髓核组织中可见类似骨组织的钙化组织，如在截肢部位形成屏障，沿根内表面分布，髓核组织中也有一些随机分布。在第三周，骨组织普遍钙化。在某些情况下，由于骨样组织的沉积，根管变窄。我们研究的病例显示了不同数量的骨样组织的形成及其分布。这种可变性可能归因于我们研究中使用的BMP和tgf - β的数量，这可能因病例而异。tgf - β超家族包括许多亚型，rhBMP-2被认为是该家族中与牙髓组织骨形成有关的最重要的组成部分。我使用rhBMP-2与胶原蛋白混合，而不是使用从胫骨提取的不溶性部分，得到了与上述相同的结果。因此，这一结果证实了rhBMP-2是牙髓组织中骨样组织形成的最重要的成分。

The objective of this study is to investigate the effects of both Bone morphogenic proteins (BMPs) and transforming growth factor-beta (TGF-beta) on the wound healing of the pulp.First, the water insoluble fraction extracted from Tibia of rat which contained both BMP and TGF-beta was mixed with saline. This mixture was placed on the mesial portion of the pulp chamber, overlying the radicular pulp of the mesial root of maxillary 1st molar.In the first week after placement of the above mentioned mixture, inflammation and formation of fibrous tissues was seen in different areas such as near the apex, at the site of amputation and the central region of the radicular pulpal tissue.In the 2nd week, calcified tissue which closely resembled bone tissue was seen scatterred in the readicular pulpal tissue, such as at the site of amputation where it formed a barrier, along the inner surface of the root and some randomly in the pulpal tissue.In the 3rd week, bone tissue generally became more calcified. In some cases root canal became narrower due to deposition of bone like tissue.The cases we studied showed varied amount of bone like tissue formation and its distribution. This variability may be attributed to the amount of BMP and TGF-beta used in our study which may have been different from case to case.TGF-beta super family includes many subtypes and rhBMP-2 is supposed to be the most important component of this family in relation to bone formation in the pulpal tissue. I obtained the same results as above by using rhBMP-2 mixed with collagen rather than using insoluble fraction extracted from Tibia. Therefore, this result confirms rhBMP-2 is the most important component in the formation of bone like tissue in the pulpal tissue.