Influence of Pregnancy on the Inflammatory Process Following Direct Pulp Capping: a Preliminary Study in Rats

Abstract The purpose of this study was to evaluate the inflammatory process following direct pulp capping during pregnancy. This experimental study involved 48 maxillary first molars of female Wistar rats. The procedures were performed in pregnant and non-pregnant animals (n =20 each). Direct pulp capping with mineral trioxide aggregate (MTA) and restoration with a light-cured resin composite was performed in half of exposed pulp specimens. In the other half of specimens, light-cured composite was placed directly on the exposed pulp. In the control groups (n=4 each), no intervention was performed. Animals were euthanized at 3 and 7 days. All sections (three per slide) were viewed under an optical microscope. One previously calibrated pathologist performed descriptive analysis and assigned scores for inflammatory response and tissue organization adjacent to the pulp exposure. The Kappa value for intra-examiner variability was 0.91. At 3 days, in animals treated with MTA, inflammatory infiltrate was absent in non-pregnant animals while mild inflammatory infiltrate was observed in some pregnant animals. The inflammatory response ranged from mild to severe in both groups treated with composite alone. At 7 days, the inflammatory response was more intense in pregnant than in non-pregnant animals treated with MTA; while this difference were not evident in animals treated with composite alone. In conclusion, pregnancy may not influence the inflammatory process following direct pulp capping with light-cured resin composite, which was always harmful to the pulp; while the tissue response after the direct pulp with MTA were more favorable in non-pregnant animals.

摘要
本研究旨在评估妊娠期直接盖髓术（direct pulp capping）后的炎症反应进程。本实验性研究纳入48颗雌性Wistar大鼠的上颌第一磨牙，将实验动物分为妊娠组与非妊娠组，每组各20只。针对暴露的牙髓样本，半数采用三氧化矿物盐聚合物（mineral trioxide aggregate, MTA）行直接盖髓术，随后以光固化复合树脂（light-cured resin composite）进行充填修复；剩余半数样本仅将光固化复合树脂直接覆盖于暴露牙髓表面。对照组（每组各4只）未施加任何干预措施。分别于术后3天和7天对动物实施安乐处死。所有切片（每张载玻片含3个切片）均在光学显微镜下进行观察。由1名经过统一校准的病理医师完成描述性分析，并对牙髓暴露区域邻近的炎症反应与组织结构进行评分。检验者内部一致性检验的Kappa值为0.91。
术后3天时，MTA治疗组的非妊娠动物未出现炎症浸润，而部分妊娠动物可见轻度炎症浸润；仅采用复合树脂治疗的两组（妊娠与非妊娠）炎症反应均表现为轻度至重度。术后7天时，MTA治疗组的妊娠动物炎症反应较非妊娠动物更为显著；而仅采用复合树脂治疗的两组间未观察到明显差异。
综上，妊娠期对光固化复合树脂直接盖髓术后的炎症过程无显著影响，此类治疗始终对牙髓具有损伤性；而采用MTA行直接盖髓术后，非妊娠动物的组织应答效果更优。