ABSTRACT

This study aimed to determine the effect of the testing method configuration on the bi-axial flexural strength (BFS) of three resin-based dental composites (RDCs). A total of 180 disc-shaped samples (12 mm diameter x 1 mm thickness) for each RDC were fabricated using split back nylon mould. The BFS was determined for specimens made in three commercial RDCs; microhybrid (MH), nanofilled paste (NFP) and nanofilled flowable (NFF) using the ring-on-ring (RoR; n = 90 for each RDC specimens) and ball-on-ring (BoR; n = 90 for each RDC specimens) configurations at a cross-head speed of 1 mm/min. RDC specimens of MH and NFP tested in the BoR configuration showed higher mean BFS values compared to those tested in the RoR configuration. (p < 0.001). The effect of test configuration on BFS values was insignificant for the specimens belonging to the NFF group (p = 0.207). Moreover, the Weibull modulus of NFF in the RoR configuration was statistically lower compared to those for NFF in the BoR configuration as the 95% confidence interval of Weibull modulus did not overlap.

The specimen support and testing configuration significantly impacted the BFS value of the RDCs. The Weibull statistics appeared to be inappropriate for all kinds of RDCs.

摘要

本研究旨在确定测试方法配置对三种树脂基牙科复合材料 (RDC) 的双轴弯曲强度 (BFS) 的影响。每个 RDC 总共有 180 个圆盘形样品（直径 12 毫米 x 厚度 1 毫米）使用分背尼龙模具制造。BFS 是针对在三个商业 RDC 中制造的样本确定的；使用环对环（RoR；每个 RDC 样品 n = 90）和球环（BoR；每个 RDC 样品 n = 90）的微混合 (MH)、纳米填充糊剂 (NFP) 和纳米填充流动性 (NFF) ) 以 1 毫米/分钟的十字头速度配置。与在 RoR 配置中测试的那些相比，在 BoR 配置中测试的 MH 和 NFP 的 RDC 样本显示出更高的平均 BFS 值。( p< 0.001)。对于属于 NFF 组的样本，测试配置对 BFS 值的影响不显着（p = 0.207）。此外，与 BoR 配置中的 NFF 相比，RoR 配置中 NFF 的 Weibull 模量在统计学上较低，因为 Weibull 模量的 95% 置信区间没有重叠。

样本支持和测试配置显着影响了 RDC 的 BFS 值。Weibull 统计数据似乎不适用于所有类型的 RDC。