Background: Local delivery agents (LDA) have the advantage of delivering the antibiotics at high concentrations to the targeted sites. However, the constant flow of gingival crevicular fluids and saliva may restrict their efficacy. Therefore, the drug sustainability and pharmacodynamic properties of any proposed LDA should be evaluated. Methods: Four dental implants were placed unilaterally in the edentulous mandible of six beagle dogs. Peri-implantitis were experimentally induced using silk-ligatures. Each implant was randomly allocated to receive one of the following four treatments: (i) MC (Chitosan-alginate (CA) minocycline), (ii) MP (CA-without minocycline), (iii) PG (Polyacrylate-glycerin minocycline), and (iv) Control (mechanical debridement only). Mechanical therapies and LDAs were administered into the gingival sulcus two times at a 4-week interval. Drug sustainability as well as clinical, radiographical, and immunohistochemical (IHC) analyses were conducted to evaluate the efficacies of treatments. Results: Reduced mean probing depth was observed in all of the test groups after the second delivery. A minimal marginal bone level change was observed during the treatment period (MP (−0.06 ± 0.53 mm) to PG (−0.25 ± 0.42 mm)). The distribution of IHC cell marker analysis of all targeted antibodies ranged from 6.34% to 11.33%. All treatment outcomes between the test groups were comparable. A prolonged retention of LDA was observed from CA microspheres (MC and MP) at both administrations (p < 0.017) and prolonged sustainability of bacteriostatic effect was observed from MC compared to PG after the second administration (p < 0.05). Conclusions: Prolonged retention of CA microspheres was observed and the longer bacteriostatic effect was observed from the MC group. Mechanical debridement with adjunct LDA therapy may impede peri-implantitis progression, however, prolonged drug action did not lead to improved treatment outcome.

中文翻译：

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局部米诺环素药物治疗围植入物炎的功效：比格犬体内的实验研究。

背景：局部递送剂（LDA）具有将高浓度抗生素递送到目标部位的优势。但是，龈沟液和唾液的不断流动可能会限制其功效。因此，应评估任何提议的LDA的药物可持续性和药效学性质。方法：将四颗牙种植体单侧放置在六只比格犬的无牙颌中。实验中使用丝结扎法诱发了种植体周围炎。每个植入物均被随机分配以接受以下四种治疗方法之一：（i）MC（壳聚糖-海藻酸酯（CA）米诺环素），（ii）MP（无米诺环素的CA），（iii）PG（聚丙烯酸酯-甘油米诺环素）， （iv）控制（仅机械清创术）。机械疗法和LDA每4周间隔两次进入牙龈沟。进行了药物可持续性以及临床，放射照相和免疫组化（IHC）分析，以评估治疗效果。结果：第二次分娩后，所有测试组的平均探测深度均降低。在治疗期间观察到最小的边缘骨水平变化（MP（-0.06±0.53 mm）至PG（-0.25±0.42 mm））。IHC细胞标记物分析的所有靶向抗体的分布范围为6.34％至11.33％。测试组之间的所有治疗结果均具有可比性。两种给药方式均从CA微球（MC和MP）观察到LDA的保留时间延长（并进行了免疫组化（IHC）分析以评估治疗效果。结果：第二次分娩后，所有测试组的平均探测深度均降低。在治疗期间观察到最小的边缘骨水平变化（MP（-0.06±0.53 mm）至PG（-0.25±0.42 mm））。IHC细胞标记物分析的所有靶向抗体的分布范围为6.34％至11.33％。测试组之间的所有治疗结果均具有可比性。两种给药方式均从CA微球（MC和MP）观察到LDA的保留时间延长（并进行了免疫组化（IHC）分析以评估治疗效果。结果：第二次分娩后，所有测试组的平均探测深度均降低。在治疗期间观察到最小的边缘骨水平变化（MP（-0.06±0.53 mm）至PG（-0.25±0.42 mm））。IHC细胞标记物分析的所有靶向抗体的分布范围为6.34％至11.33％。测试组之间的所有治疗结果均具有可比性。两种给药方式均从CA微球（MC和MP）观察到LDA的保留时间延长（25±0.42毫米））。IHC细胞标记物分析的所有靶向抗体的分布范围为6.34％至11.33％。测试组之间的所有治疗结果均具有可比性。两种给药方式均从CA微球（MC和MP）观察到LDA的保留时间延长（25±0.42毫米））。IHC细胞标记物分析的所有靶向抗体的分布范围为6.34％至11.33％。测试组之间的所有治疗结果均具有可比性。两种给药方式均从CA微球（MC和MP）观察到LDA的保留时间延长（p <0.017），并且与第二次给药后的PG相比，从MC观察到抑菌作用的持续性延长（p <0.05）。结论：MC组观察到CA微球的保留时间延长，抑菌作用更长。辅助LDA治疗的机械性清创术可能会阻碍种植体周围炎的进展，但是，长时间的药物作用并不能改善治疗效果。