Department of Endodontics, University of Texas Health Science Center at San Antonio, San Antonio, Texas.
Department of Endodontics, University of Texas Health Science Center at San Antonio, San Antonio, Texas.
J Endod. 2019 Sep;45(9):1119-1125. doi: 10.1016/j.joen.2019.05.004. Epub 2019 Jul 2.
Several studies have reported regeneration of the pulp-dentin complex when treating noninfected root canal systems. However, current protocols applied to infected root canal systems are much less predictable for the formation of dentin. Converging lines of evidence implicate residual biofilm as an important factor for these variable histologic outcomes. Here we studied the effect of a residual polymicrobial biofilm on the release of transforming growth factor beta 1 (TGF-β1) from dentin. We hypothesized that the presence of bacterial biofilm attenuates the release of bioactive molecules from dentin.
Using bacteria commonly found in infected immature teeth, we developed a multispecies biofilm in an organotypic root canal model. Root segments were then subjected to various irrigation or intracanal medicament protocols. Subsequently, the release of TGF-β1 from dentin was measured using the enzyme-linked immunosorbent assay.
Our data show that sterile root segments released greater amounts of TGF-β1 when conditioned with 17% EDTA alone (P < .001) or with the combination of 1.5% sodium hypochlorite and 17% EDTA (P < .05) compared with root segments infected with the multispecies biofilm. Similar results were also observed with the intracanal medicament protocol. Sterile root segments medicated with various concentrations of triple antibiotic paste and full-strength calcium hydroxide released greater amounts of TGF-β1 when compared with their infected counterparts.
This is the first study to report the detrimental effects of a residual biofilm on dentin conditioning and, therefore, the release of growth factors critical for regenerative procedures.
几项研究报告称，在治疗非感染性根管系统时，牙髓-牙本质复合体可以再生。然而，目前应用于感染性根管系统的方案对于牙本质的形成预测性要差得多。越来越多的证据表明，残留生物膜是这些可变组织学结果的一个重要因素。在这里，我们研究了残留多微生物生物膜对转化生长因子β 1（TGF-β1）从牙本质中释放的影响。我们假设细菌生物膜的存在会减弱牙本质中生物活性分子的释放。
我们使用常见于感染性未成熟牙齿的细菌，在器官型根管模型中开发了一种多物种生物膜。然后，将根段用各种冲洗或根管内药物方案处理。随后，使用酶联免疫吸附试验测量 TGF-β1 从牙本质中的释放量。
我们的数据表明，与感染了多物种生物膜的根段相比，无菌根段在用 17% EDTA 单独（P<0.001）或 1.5%次氯酸钠和 17% EDTA 组合（P<0.05）处理时，释放出更多的 TGF-β1。在根管内药物方案中也观察到了类似的结果。用不同浓度的三联抗生素糊剂和全强度氢氧化钙处理的无菌根段释放出的 TGF-β1 量明显多于感染根段。
这是第一项报告残留生物膜对牙本质调理和因此对再生程序关键生长因子释放的不利影响的研究。
