不同深边缘设计对整体氧化锆全瓷冠修复牙体抗折裂性能的影响。

Different Designs of Deep Marginal Elevation and Its Influence on Fracture Resistance of Teeth with Monolith Zirconia Full-Contour Crowns.

机构信息

Conservative Dental Science Department, College of Dentistry, Prince Sattam bin Abdulaziz University, Al Kharj 11942, Saudi Arabia.

Dental Intern, College of Dentistry, Prince Sattam bin Abdulaziz University, Al Kharj 11942, Saudi Arabia.

出版信息

Medicina (Kaunas). 2023 Mar 27;59(4):661. doi: 10.3390/medicina59040661.

DOI:10.3390/medicina59040661

PMID:37109619

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC10144512/

Abstract

Even with the demand for high esthetics, the strength of the material for esthetic applications continues to be important. In this study, monolith zirconia (MZi) crowns fabricated using CAD/CAM were tested for fracture resistance (FR) in teeth with class II cavity designs with varying proximal depths, restored through a deep marginal elevation technique (DME). : Forty premolars were randomly divided into four groups of ten teeth. In Group A, tooth preparation was conducted and MZi crowns were fabricated. In Group B, mesio-occluso-distal (MOD) cavities were prepared and restored with microhybrid composites before tooth preparation and the fabrication of MZi crowns. In Groups C and D, MOD cavities were prepared, differentiated by the depth of the gingival seat, 2 mm and 4 mm below the cemento-enamel junction (CEJ). Microhybrid composite resin was used for DME on the CEJ and for the restoration of the MOD cavities; beforehand, tooth preparations were conducted and MZi crowns were and cemented using resin cement. The maximum load to fracture (in newtons (N)) and FR (in megapascals (MPa)) were measured using the universal testing machine. The average scores indicate a gradual decrease in the load required to fracture the samples from Groups A to D, with mean values of 3415.61 N, 2494.11 N, 2108.25 N and 1891.95 N, respectively. ANOVA revealed highly significant differences between the groups. Multiple group comparisons using the Tukey HSD post hoc test revealed that Group D had greater DME depths and showed significant differences compared with Group B. FR in teeth decreased when more tooth structure was involved, even with MZi crowns. However, DME up to 2 mm below the CEJ did not negatively influence the FR. Strengthening the DME-treated teeth with MZi crowns could be a reasonable clinical option, as the force required to fracture the samples far exceeded the maximum recorded biting force for posterior teeth.

摘要

即使对美观有很高的要求，用于美学应用的材料强度仍然很重要。在这项研究中，使用 CAD/CAM 制造的单体氧化锆（MZi）牙冠用于测试具有不同近中深度的 II 类洞型设计的牙齿的抗断裂能力（FR），通过深边缘抬高技术（DME）进行修复。将 40 颗前磨牙随机分为四组，每组 10 颗。在 A 组中，进行牙体预备并制作 MZi 牙冠。在 B 组中，制备近中-颊-舌（MOD）窝洞并用微混合复合材料进行修复，然后再进行牙体预备和 MZi 牙冠的制作。在 C 组和 D 组中，制备 MOD 窝洞，通过龈缘下 2 毫米和 4 毫米区分，在牙颈部下方 2 毫米和 4 毫米处使用微混合复合材料进行 DME，用于修复 MOD 窝洞；在此之前，进行牙体预备并使用树脂水门汀黏固 MZi 牙冠。使用万能试验机测量断裂时的最大载荷（以牛顿（N）为单位）和 FR（以兆帕斯卡（MPa）为单位）。平均得分表明，从 A 组到 D 组，断裂样品所需的载荷逐渐降低，平均值分别为 3415.61 N、2494.11 N、2108.25 N 和 1891.95 N。方差分析显示组间存在高度显著差异。使用 Tukey HSD 事后检验进行的多组比较显示，D 组的 DME 深度更大，与 B 组相比有显著差异。即使使用 MZi 牙冠，牙齿的 FR 也会随着更多的牙体结构的参与而降低。然而，DME 至牙颈部下方 2 毫米处不会对 FR 产生负面影响。用 MZi 牙冠加强 DME 处理过的牙齿可能是一种合理的临床选择，因为断裂样品所需的力远远超过后牙记录的最大咬合力。