Park So-Min, Kim David-Hyungjin, Pang Eun-Kyoung
Department of Periodontology, School of Medicine (Head: Prof. Dr. K.-H. Kim), Ewha Womans University, Seoul, Republic of Korea.
Division of Biological Science, University of California, San Diego, USA.
J Craniomaxillofac Surg. 2017 Jun;45(6):903-912. doi: 10.1016/j.jcms.2017.03.007. Epub 2017 Mar 21.
To evaluate structural and physicochemical characteristics of demineralized human dentin block with increasing demineralization time and to assess new bone formation when onlay grafted at different demineralization times in rat calvaria.
Extracted human permanent teeth were pretreated and demineralized for 10-90 min. Scanning electron microscopy, X-ray diffraction analysis, inductively coupled plasma spectrometry, and energy dispersive X-ray analysis were performed. Demineralized dentin blocks (DDBs) with the representatives of the different demineralization times (10 and 60 min) were implanted in vivo onto rat calvaria (male Sprague-Dawley, n = 20 for each carrier). For controls, collagen sponge and human freeze-dried corticocancellous bone blocks (FDBB) were implanted onto calvaria (n = 20). The rats were sacrificed 2 or 8 weeks postoperatively and evaluated radiographically, histologically, and histomorphometrically.
With increasing demineralization time, the surface structure of dentin blocks showed increased number and size of dentinal tubules. Moreover, the organic components increased, whereas inorganic components decreased. Crystallinity decreased sharply between 10 and 30 min demineralization time. In our in vivo study, at both time points, animals with DDBs showed significantly better bone formation than controls (p < 0.05). The DDB/60 group showed significantly increased new bone area and bone density than the DDB/10 group at 8 weeks (p < 0.05), but showed higher resorption that significantly decreased total augmented area compared with the DDB/10 group (p < 0.05).
DDB increased new bone formation and bone density. Further studies are needed to determine the optimal demineralization time to maximize space maintenance and bone formation of the graft material.
评估随着脱矿时间增加，脱矿人牙本质块的结构和物理化学特性，并评估在大鼠颅骨不同脱矿时间进行覆盖移植时的新骨形成情况。
提取的人类恒牙经过预处理并脱矿10 - 90分钟。进行扫描电子显微镜、X射线衍射分析、电感耦合等离子体质谱分析和能量色散X射线分析。将代表不同脱矿时间（10分钟和60分钟）的脱矿牙本质块（DDB）植入雄性Sprague-Dawley大鼠颅骨体内（每种载体n = 20）。作为对照，将胶原海绵和人类冻干皮质松质骨块（FDBB）植入颅骨（n = 20）。术后2周或8周处死大鼠，并进行放射学、组织学和组织形态计量学评估。
随着脱矿时间增加，牙本质块的表面结构显示牙本质小管数量和尺寸增加。此外，有机成分增加，而无机成分减少。在脱矿10至30分钟之间，结晶度急剧下降。在我们的体内研究中，在两个时间点，植入DDB的动物显示出比对照组明显更好的骨形成（p < 0.05）。在8周时，DDB/60组的新骨面积和骨密度比DDB/10组显著增加（p < 0.05），但与DDB/10组相比，其吸收更高，显著降低了总增加面积（p < 0.05）。
DDB增加了新骨形成和骨密度。需要进一步研究以确定最佳脱矿时间，以使移植材料的空间维持和骨形成最大化。
