Objective

To evaluate the edge chip resistance ($R_{\mathit{eA}}$) of two CAD/CAM monolithic ceramics (GC- IPS e.max CAD and YZ- Zenostar Zr Translucent) bonded to a dentine analogue substrate (G10- NEMA G10).

Methods

Plate-shaped specimens were prepared from GC and YZ ceramics and were either bonded (B) to G10 or attached (NB) to a universal testing machine for edge chipping test. Samples from all groups (GC-B, GC-NB, YZ-B and YZ-NB) were indented (n = 25) at different edge distances (d = 0.1, 0.2, 0.3, 0.4, 0.5 and 0.6 mm) to produce chips. Force (F, in N) and d values were recorded and $R_{\mathit{eA}}$ (in N/mm) were calculated. Data were statistically analyzed using Pearson´s correlation, Student t, ANOVA and Tukey tests (α = 0.05).

Results

A strong correlation (R ≥ 0.98) was found between F and d values for all groups. $R_{\mathit{eA}}$ values increased with increasing d, irrespective of ceramic type (GC and YZ) or fixation method (B and NB). Significant differences (p < 0.05) in mean $R_{\mathit{eA}}$ values were found between B and NB ceramics at lower d (0.1–0.3 mm) that did not persist (p > 0.05) at greater d (0.5 and 0.6 mm), meaning, bonding (B) to G10 protected both materials against chipping close to the edge.

Conclusions

The larger the distance from the occlusal contact to the restoration edge, the greater the chance to avoid ceramic chipping in monolithic restorations. For d ≤ 0.3 mm, such F vs d relation is less critical for edge resistance of YZ and for resin bonded monolithic ceramics.

中文翻译：

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粘结到牙本质类似物上的陶瓷的抗边缘崩裂性。

客观的

评估边缘芯片电阻（${\mathrm{[R}}_{\mathit{A}}$）粘合在牙本质类似物基质（G10-NEMA G10）上的两个CAD / CAM整体陶瓷（GC-IPS e.max CAD和YZ- Zenostar Zr Translucent）。

方法

用GC和YZ陶瓷制备板状样品，然后将其粘结（B）到G10上，或者将其附着（NB）到通用测试机上进行边缘碎裂测试。将所有组（GC-B，GC-NB，YZ-B和YZ-NB）的样品在不同的边缘距离（d = 0.1、0.2、0.3、0.4、0.5和0.6 mm）处压痕（n = 25）以产生筹码。记录力（F，以N为单位）和d值，${\mathrm{[R}}_{\mathit{A}}$（以N / mm计）。使用Pearson相关系数，Student t，ANOVA和Tukey检验（α= 0.05）对数据进行统计分析。

结果

在所有组的F和d值之间都发现了很强的相关性（R≥0.98）。 ${\mathrm{[R}}_{\mathit{A}}$值随d的增加而增加，而与陶瓷类型（GC和YZ）或固定方法（B和NB）无关。均值差异显着（p <0.05）${\mathrm{[R}}_{\mathit{A}}$ 在较低的d（0.1-0.3 mm）处发现B和NB陶瓷之间的值，在较大的d（0.5和0.6 mm）处不持久（p> 0.05），这意味着（B）与G10的结合可保护两种材料免于碎裂到边缘。

结论

从咬合接触到修复体边缘的距离越大，在整体修复体中避免陶瓷碎裂的机会就越大。对于d≤0.3 mm，这样的F vs d关系对于YZ的边缘电阻和树脂粘结的整体陶瓷而言并不那么关键。