Camps J, Tardieu C, Déjou J, Franquin J C, Ladaique P, Rieu R
Unité IMEB, Faculté d'Odontologie, Marseille, France.
Dent Mater. 1997 Jan;13(1):34-42. doi: 10.1016/s0109-5641(97)80006-1.
Most of the devices used to evaluate the cytotoxicity of resin-based composites in vitro use a dentin barrier test. However, it is difficult to obtain the number of freshly extracted teeth, all on the same day, that is necessary for powerful statistical analysis. Tooth cryopreservation provides a way to build up a supply of teeth. This in vitro study compared cryopreserved teeth and freshly extracted teeth in an evaluation of the cytotoxicity of resin-based composites. In addition, this study also evaluated the effects of pulsatile pressure and the importance of dentin permeability on the cytotoxic response to bonding resins.
Forty freshly extracted and forty cryopreserved third molars were used. A standardized Class I cavity was prepared within the dentin. The hydraulic conductance of each tooth was recorded. The cavities were filled either with Scotchbond Multi-Purpose Plus and Z 100 (3M Dental Products) or with Optibond and Herculite (Kerr). A plexiglas device was designed to permit 24 h long contact between culture medium and the roof of the pulp chamber while a pulsatile pulpal pressure was simulated. The viability of L 929 cells cultured with a control medium and evaluated by an MTT assay was compared to that of L 929 cells cultured with medium which remained for 24 h in contact with the pulp chamber of restored teeth. A three-way ANOVA was used to compare the cytotoxicity among the different groups. A simple least-squares linear regression was used to seek a relationship between the hydraulic conductance of dentin and the cytotoxicity of composite restorative materials.
No significant differences in cytotoxicity were found between the freshly extracted teeth and the cryopreserved teeth (p = 0.53). The cytotoxicity of the resin adhesives was statistically higher when a pulsatile pulpal pressure was simulated (p = 0.04). A significant relationship was found between the hydraulic conductance of dentin and the cytotoxicity of resin-based composites (p = 0.02).
Cryopreserved teeth can be used for in vitro evaluation of the cytotoxicity of resin adhesives. Pulsatile pulpal pressure simulations increased the in vitro cytotoxicity of the tested materials.
大多数用于体外评估树脂基复合材料细胞毒性的装置采用牙本质屏障试验。然而，很难在同一天获得进行有力统计分析所需的新鲜拔除牙齿数量。牙齿冷冻保存提供了一种积累牙齿供应的方法。这项体外研究在评估树脂基复合材料的细胞毒性时，比较了冷冻保存的牙齿和新鲜拔除的牙齿。此外，本研究还评估了脉动压力的影响以及牙本质通透性对粘结树脂细胞毒性反应的重要性。
使用40颗新鲜拔除的和40颗冷冻保存的第三磨牙。在牙本质内制备标准化的I类洞。记录每颗牙齿的水力传导率。窝洞用Scotchbond Multi-Purpose Plus和Z 100（3M牙科产品）或Optibond和Herculite（ Kerr）充填。设计了一个有机玻璃装置，以允许培养基与髓腔顶部进行24小时的接触，同时模拟脉动牙髓压力。将用对照培养基培养并用MTT法评估的L 929细胞的活力与用与修复后牙齿的髓腔接触24小时的培养基培养的L 929细胞的活力进行比较。采用三因素方差分析比较不同组之间的细胞毒性。采用简单的最小二乘线性回归来寻找牙本质水力传导率与复合修复材料细胞毒性之间的关系。
新鲜拔除的牙齿和冷冻保存的牙齿之间在细胞毒性方面未发现显著差异（p = 0.53）。模拟脉动牙髓压力时，树脂粘结剂的细胞毒性在统计学上更高（p = 0.04）。在牙本质的水力传导率与树脂基复合材料的细胞毒性之间发现了显著关系（p = 0.02）。
冷冻保存的牙齿可用于体外评估树脂粘结剂的细胞毒性。脉动牙髓压力模拟增加了受试材料的体外细胞毒性。
