현재 시판되고 있는 ProRoot white MTA(Dentsply Tulsa, U.S.A)는 portland cement와 비슷한 성분으로 수분의 첨가로 인하여 경화 팽창하는 성질이 있고, 긴 경화 시간을 갖는다. 본 연구는 최근 개발된 OrthoMTA(BioMTA, Korea), 기존의 ProRoot white MTA(Dentsply Tulsa, U.S.A) 그리고 White portland cement(Union, Korea)를 대상으로 2008년에 개정된 치근관 충전재(KS P ISO 6876)의 요구 사항 중에서 경화 팽창과 경화 시간에 대한 연구를 하였다. 연구 결과, OrthoMTA의 경화 팽창률은 $0.08{pm}0.02%$이었고, ProRoot white MTA, White portland cement는 각각 $0.28{pm}0.06$, $0.80{pm}0.25%$였다(p<0.05). 경화 시간은 각각 $307.78{pm}3.83$분, $150.44{pm}2.35$분, $235.33{pm}9.07$분으로, ProRoot white MTA가 가장 짧았고, OrthoMTA가 가장 길었다(p<0.05).
ProRoot MTA(Dentsply Tulsa, U.S.A) which has similar component with Portland cement has setting expansion character and long setting time. Excessive expansion can cause fracture at the apical portion of the root and decreasing of volume stability. And the long setting time makes additional visits for crown restoration and slow setting process of this material can change physical properties itself. In this study, among requirements of root canal filling material(KS P ISO 6876) which is revised at 2008, we investigated the setting time and setting expansion. Objects are recently developed OrthoMTA(BioMTA, Korea), conventional ProRoot white MTA(Dentsply Tulsa, U.S.A) and White portland cement(Union, Korea). The results in setting expansion, OrthoMTA was $0.08{pm}0.02%$, ProRoot white MTA and White portland cement were each $0.28{pm}0.06$, $0.80{pm}0.25%$(p<0.05). The results in setting time, OrthoMTA, ProRoot white MTA, White portland cement were each $307.78{pm}3.83$ min, $150.44{pm}2.35$ min, $235.33{pm}9.07$ min(p<0.05).
