Department of Endodontology, School of Dentistry, Oregon Health and Science University, Portland, Oregon 97239, USA.
J Endod. 2012 May;38(5):700-3. doi: 10.1016/j.joen.2012.02.019. Epub 2012 Mar 28.
Large through-and-through lesions have been reported to heal faster and better when filled with bone graft material at the time of an apicoectomy. It is unknown what effect these have on retrograde filling materials such as white mineral trioxide aggregate (WMTA). In this study, the null hypothesis was tested that the presence of bone graft materials does not affect the microhardness of WMTA.
Freshly mixed WMTA was condensed into acrylic cylinders and preincubated aerobically at 37°C for 1 hour. Cylinders were immersed in simulated body fluid in close proximity to graft materials: xenograft (Bio-Oss, n = 60), freeze-dried bone allograft (MinerOss, n = 60), demineralized freeze-dried bone allograft (OraGraft, n = 40), and allograft (Puros, n = 60). Knoop microhardness of half the samples in each group was evaluated after 2 weeks of incubation and the remainder at 4 weeks. The values for each group were then compared with 2-way analysis of variance and Bonferroni post hoc tests.
WMTA microhardness values for Bio-Oss, MinerOss, and Puros groups were lower than those for OraGraft and control groups regardless of incubation period (P < .001); values for the OraGraft group were higher than those for the control group at 2 weeks (P < .001), with no difference at 4 weeks. Microhardness values were higher at 4 weeks compared with 2 weeks for MinerOss (P < .05), OraGraft (P < .01), and control (P < .001), with no differences for Bio-Oss and Puros groups. The null hypothesis was rejected.
Demineralized and mineralized graft materials appear to have a differential effect on the microhardness of WMTA.
当根尖切除术中同时使用骨移植材料填充贯穿性大缺损时，报告称其愈合更快、更好。目前尚不清楚这些材料对逆行充填材料（如白色矿物三氧化物聚合体（WMTA））有何影响。本研究旨在验证骨移植材料的存在不影响 WMTA 显微硬度的假设。
将新鲜混合的 WMTA 压缩到丙烯酸圆柱体中，并在 37°C 下预孵育 1 小时。圆柱体浸泡在模拟体液中，与移植材料紧密接触：异种骨（Bio-Oss，n=60）、冻干骨同种异体移植物（MinerOss，n=60）、脱矿冻干骨同种异体移植物（OraGraft，n=40）和同种异体移植物（Puros，n=60）。每组的一半样本在孵育 2 周后评估其 Knoop 显微硬度，其余样本在 4 周后评估。然后用双因素方差分析和 Bonferroni 事后检验比较各组的数值。
无论孵育期如何，Bio-Oss、MinerOss 和 Puros 组的 WMTA 显微硬度值均低于 OraGraft 和对照组（P<0.001）；OraGraft 组在 2 周时的数值高于对照组（P<0.001），而在 4 周时则无差异。与 2 周时相比，MinerOss（P<0.05）、OraGraft（P<0.01）和对照组（P<0.001）在 4 周时的显微硬度值更高，而 Bio-Oss 和 Puros 组则无差异。原假设被拒绝。
脱矿和矿化的移植材料似乎对 WMTA 的显微硬度有不同的影响。
