Keshmiri Nazanin, Alaghehmand Homayoon, Mokhtarpour Faraneh
Dental Materials Research Center, Babol University of Medical Sciences, Babol, Iran.
Department of Esthetic and Restorative Dentistry, Babol University of Medical Sciences, Babol, Iran.
Front Dent. 2020 Sep;17(22):1-7. doi: 10.18502/fid.v17i22.4316. Epub 2020 Sep 10.
This study aimed to evaluate the effects of hydrofluoric acid (HF) concentration and etching time on the surface roughness (SR) and three-point flexural strength of Suprinity and to analyze the surface elements before and after etching.
To measure the SR, 70 specimens of Suprinity (2×4×5mm) were assigned to seven groups (n=10). Six groups were etched for 20, 60, and 120 seconds with 5% and 10% HF and 7th group was the control group. Specimens were evaluated using atomic force microscopy (AFM). One specimen from each group was used to analyze the surface elements using scanning electron microscopy (SEM). For measuring the three-point flexural strength, 60 specimens were divided into six groups (n=10) and etched as previously described. The flexural strength was measured using a universal testing machine. T-test, one-way analysis of variance (ANOVA), and two-way ANOVA were used for statistical analyses (P<0.05).
The 10% concentration of HF caused higher SR compared to the 5% HF. The effect of HF concentration on the flexural strength was significantly different in the 20- and 60-second etching groups. Different etching times had no significantly different effect on the SR. With 5% HF, the flexural strength was significantly higher for 20-second etching time than for the etching times of 60 and 120 seconds. With 10% HF, there was a significant difference in flexural strength between etching times of 20 and 120 seconds. The atomic percentage (at%) of silica was enhanced by increasing the etching time.
The best surface etching protocol comprises 10% HF used for 20 seconds.
本研究旨在评估氢氟酸（HF）浓度和蚀刻时间对Suprinity表面粗糙度（SR）和三点弯曲强度的影响，并分析蚀刻前后的表面元素。
为测量SR，将70个Suprinity样本（2×4×5mm）分为七组（n = 10）。六组分别用5%和10%的HF蚀刻20、60和120秒，第七组为对照组。使用原子力显微镜（AFM）对样本进行评估。每组取一个样本，用扫描电子显微镜（SEM）分析表面元素。为测量三点弯曲强度，将60个样本分为六组（n = 10），并按上述方法蚀刻。使用万能试验机测量弯曲强度。采用t检验、单向方差分析（ANOVA）和双向ANOVA进行统计分析（P<0.05）。
与5%的HF相比，10%浓度的HF导致更高的SR。在20秒和60秒蚀刻组中，HF浓度对弯曲强度的影响有显著差异。不同的蚀刻时间对SR没有显著差异。使用5%的HF时，20秒蚀刻时间的弯曲强度明显高于60秒和120秒的蚀刻时间。使用10%的HF时，20秒和120秒蚀刻时间的弯曲强度有显著差异。通过增加蚀刻时间，二氧化硅的原子百分比（at%）增加。
最佳的表面蚀刻方案是使用10%的HF蚀刻20秒。
