<div><img onLoad='miniSelfResize(contents_4,this); if(this.parentNode.tagName=="A"){this.onclick = "";}' src="download.php?id=enews&no=4&div=0&mode=1" border="0" /></div><br>Bacteria can invade into dentinal tubules that are wider than 2.5 micron.<BR>The size of OrthoMTA is smaller than 2 micron and can be infiltrated into dentinal tubles.<BR>After Orthograde canal filling, Interfacial layer is formed between OrthoMTA and canal wall. The composition of the interfacial layer is closed to hydroxy appatite.<BR>This layer was found to be bioactive and induce bioactive effect to around tissue.<BR>Bonding of this interfacial layer is mechanical and chemical bonding. As a result, perfect apical sealing is possible in orthograde canal filling with OrthoMTA.<BR>