Bioengineering Center, University of Oklahoma, Norman, OK 73019, USA.
Dent Mater. 2013 Jun;29(6):656-65. doi: 10.1016/j.dental.2013.03.014. Epub 2013 Apr 17.
Dental implants provide support for dental crowns and bridges by serving as abutments for the replacement of missing teeth. To prevent bacterial accumulation and growth at the site of implantation, solutions such as systemic antibiotics and localized delivery of bactericidal agents are often employed. The objective of this study was to demonstrate a novel method of controlled localized delivery of antibacterial agents to an implant site using a biodegradable custom fabricated ring.
The study involved incorporating a model antibacterial agent (metronidazole) into custom designed poly-ε-caprolactone/alginate (PCL/alginate) composite rings to produce the intended controlled release profile. The rings can be designed to fit around the body of any root form dental implants of various diameters, shapes and sizes.
In vitro release studies indicate that pure (100%) alginate rings exhibited an expected burst release of metronidazole in the first few hours, whereas Alginate/PCL composite rings produced a medium burst release followed by a sustained release for a period greater than 4 weeks. By varying the PCL/alginate weight ratios, we have shown that we can control the amount of antibacterial agents released to provide the minimal inhibitory concentration (MIC) needed for adequate protection. The fabricated composite rings have achieved a 50% antibacterial agent release profile over the first 48 h and the remaining amount slowly released over the remainder of the study period. The PCL/alginate agent release characteristic fits the Ritger-Peppas model indicating a diffusion-based mechanism during the 30-day study period.
The developed system demonstrates a controllable drug release profile and the potential for the ring to inhibit bacterial biofilm growth for the prevention of diseases such as peri-implantitis resulting from bacterial infection at the implant site.
种植牙通过作为缺失牙齿的基台为牙冠和牙桥提供支撑。为了防止植入部位细菌的积聚和生长，通常会使用全身抗生素和局部递送杀菌剂等解决方案。本研究的目的是展示一种使用可生物降解定制环控制局部递抗菌剂到植入部位的新方法。
本研究将模型抗菌剂（甲硝唑）纳入定制设计的聚己内酯/藻酸盐（PCL/藻酸盐）复合环中，以产生预期的控制释放曲线。这些环可以设计为适合各种直径、形状和尺寸的任何根形式种植牙的体部。
体外释放研究表明，纯（100%）藻酸盐环在最初的几个小时内表现出甲硝唑的预期突释，而藻酸盐/PCL 复合环产生中突释，随后持续释放超过 4 周。通过改变 PCL/藻酸盐的重量比，我们已经表明我们可以控制释放的抗菌剂的量，以提供足够保护所需的最小抑菌浓度（MIC）。所制造的复合环在最初的 48 小时内实现了 50%的抗菌剂释放曲线，其余的则在研究期间的剩余时间内缓慢释放。PCL/藻酸盐的药物释放特性符合 Ritger-Peppas 模型，表明在 30 天的研究期间存在基于扩散的机制。
所开发的系统展示了可控的药物释放曲线，并且该环有可能抑制细菌生物膜的生长，从而预防因植入部位细菌感染引起的疾病，如种植体周围炎。
