BackgroundThis study aimed to analyze the influence of concave and cylindrical abutments on peri‐implant soft tissue. Dimensions, collagen fiber orientation, and immunohistochemical data were assessed.MethodsA multicenter, split‐mouth, double‐blind randomized clinical trial was conducted. Two groups were analyzed: cylindrical abutments and concave abutments. After a 12‐week healing period, peri‐implant soft tissue samples were collected, processed, and evaluated for dimensions, collagen fiber orientation, and immunohistochemical data. Inflammatory infiltration and vascularization were assessed, and the abutment surfaces were analyzed using scanning electron microscopy. The statistical analysis was performed using the SPSS version 20.0 statistical package.ResultsA total of 74 samples in 37 patients were evaluated. Histological evaluation of peri‐implant soft tissue dimensions revealed significant differences between concave and cylindrical abutments. Concave abutments exhibited greater total height (concave: 3.57 ± 0.28 – cylindrical: 2.95 ± 0.27) and barrier epithelium extension (concave: 2.46 ± 0.17 – cylindrical: 1.89 ± 0.21) (p < 0.05), while the supracrestal connective tissue extension (concave: 1.11 ± 0.17 – cylindrical: 1.03 ± 0.16) was slightly greater (p > 0.05). Collagen fiber orientation favored concave abutments (23.76 ± 5.86), with significantly more transverse/perpendicular fibers than for cylindrical abutments (15.68 ± 4.57). The immunohistochemical analysis evidenced greater inflammatory and vascular intensity in the lower portion for both abutments, though concave abutments showed lower overall intensity (concave: 1.05 ± 0.78 – cylindrical: 1.97 ± 0.68) (p < 0.05). The abutment surface analysis demonstrated a higher percentage of tissue remnants on concave abutments (42.47 ± 1.32; 45.12 ± 3.03) (p < 0.05).ConclusionsWithin the limitations of this study, concave abutments presented significantly greater peri‐implant tissue height, linked to an extended barrier epithelium, versus cylindrical abutments in thick tissue phenotype. This enhanced soft tissue sealing, favoring a greater percentage of transversely oriented collagen fibers. The concave design reduced chronic inflammatory exudation with T and B cells, thus minimizing the risk of chronic inflammation.Plain Language SummaryThis study looked at how 2 different shapes of dental implant abutments (the parts that connect the implant to the crown), specifically concave and cylindrical, affect the soft tissue around the implants. We wanted to see how these shapes influenced the tissue's size, structure, and health. We conducted a clinical trial with 37 patients, comparing the 2 types of abutments in the same mouth over 12 weeks.Our findings showed that the concave abutments led to a taller and more extensive layer of protective tissue around the implant compared to the cylindrical ones. This protective tissue had more favorable collagen fiber orientation, which is important for the strength and health of the tissue. Additionally, the concave abutments resulted in less inflammation and better tissue integration.In conclusion, concave abutments may provide better support and health for the soft tissue around dental implants, reducing the risk of chronic inflammation and potentially leading to better long‐term outcomes for patients with dental implants

中文翻译：

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对圆柱形和凹形基台的组织学和免疫组织化学软组织反应：多中心随机临床试验


背景本研究旨在分析凹形基台和圆柱形基台对种植体周围软组织的影响。评估尺寸、胶原纤维取向和免疫组织化学数据。方法进行多中心、分口、双盲随机临床试验。分析了两组：圆柱形基台和凹形基台。 12 周愈合期后，收集、处理种植体周围软组织样本，并评估其尺寸、胶原纤维方向和免疫组织化学数据。评估炎症浸润和血管形成，并使用扫描电子显微镜分析基台表面。使用SPSS 20.0版统计软件包进行统计分析。结果共评估37名患者的74个样本。种植体周围软组织尺寸的组织学评估显示凹形基台和圆柱形基台之间存在显着差异。凹形基台表现出更大的总高度（凹形：3.57 ± 0.28 – 圆柱形：2.95 ± 0.27）和屏障上皮延伸（凹形：2.46 ± 0.17 – 圆柱形：1.89 ± 0.21）（p < 0.05），而牙槽嵴上结缔组织延伸（凹面：1.11 ± 0.17 – 圆柱形：1.03 ± 0.16) 稍大 (p > 0.05)。胶原纤维取向有利于凹形基台 (23.76 ± 5.86)，横向/垂直纤维明显多于圆柱形基台 (15.68 ± 4.57)。免疫组织化学分析表明，两个基台下部的炎症和血管强度较高，但凹形基台显示出较低的整体强度（凹形基台：1.05 ± 0.78 – 圆柱形：1.97 ± 0.68）（p < 0.05）。 基台表面分析表明凹基台上的组织残余物百分比较高 (42.47 ± 1.32; 45.12 ± 3.03) (p < 0.05)。 结论 在本研究的限制范围内，凹基台呈现出明显更高的种植体周围组织高度，这与延伸的屏障上皮，与厚组织表型中的圆柱形基台相比。这增强了软组织密封，有利于更大比例的横向胶原纤维。凹面设计减少了 T 细胞和 B 细胞的慢性炎症渗出，从而最大限度地降低了慢性炎症的风险。 通俗易懂的总结这项研究着眼于 2 种不同形状的牙种植体基台（将种植体连接到牙冠的部分），特别是凹面和圆柱形，影响种植体周围的软组织。我们想了解这些形状如何影响组织的大小、结构和健康。我们对 37 名患者进行了一项临床试验，在 12 周内比较了同一口中的两种基台。我们的研究结果表明，与圆柱形基台相比，凹形基台在种植体周围形成了更高、更广泛的保护组织层。这种保护组织具有更有利的胶原纤维取向，这对于组织的强度和健康很重要。此外，凹形基台可减少炎症并改善组织整合。总之，凹形基台可以为牙种植体周围的软组织提供更好的支撑和健康，降低慢性炎症的风险，并可能为牙种植体患者带来更好的长期结果