Uribe-Hernández Loraine, Latorre-Correa Federico, Perea-Lowery Leila, Ardila Carlos M
Prosthodontics Postgraduate Program, School of Dentistry, University of Antioquia, Medellín, Colombia.
Titular Professor, Prosthodontics Postgraduate Program, School of Dentistry, University of Antioquia, Medellín, Colombia.
J Clin Exp Dent. 2024 Aug 1;16(8):e975-e983. doi: 10.4317/jced.61769. eCollection 2024 Aug.
Inadequate polymerization of resins is a major cause of failure in dental restorations. This study aimed to evaluate the hypothesis that both polymerization distance and preheating of four nanohybrid resins significantly affect their degree of conversion (DC).
Four A2-colored nanohybrid resins were selected: Filtek Z250 XT (3M), Tetric N-Ceram (Ivoclar), Zafira (New Stetic), and Spectra Smart (Dentsply). These resins were chosen due to their varied compositions. Forty-eight discs (6 mm diameter, 2 mm thickness) were manufactured, with 24 discs preheated to 39°C. All discs were polymerized for 40 seconds at distances of 1 mm and 6 mm using the Bluephase N lamp (Ivoclar Vivadent), operating at 385-515 nm and 1200 mW/cm². The polymerized discs were stored in distilled water at 37°C for 24 hours, and the DC was measured using Fourier-transform infrared spectroscopy (FTIR). Statistical analysis was performed using one-way ANOVA and independent samples t-tests.
No statistically significant differences in DC were observed between samples preheated to 39°C and those at room temperature (> 0.05). Zafira exhibited the highest DC, significantly higher than Z250 XT in all groups (< 0.005) and higher than Tetric N-Ceram on the surface (< 0.05). Significant differences were also found between Zafira and Spectra Smart in specific conditions (< 0.05). No significant differences in DC were found between polymerization distances of 1 mm and 6 mm. Uniform polymerization was achieved throughout the resin discs.
Preheating nanohybrid resins to 39°C had no statistically significant impact on their degree of conversion. Acceptable DC values were achieved using a high-intensity lamp for 40 seconds, even at a curing distance of 6 mm. Among the tested resins, Zafira demonstrated the highest DC under various conditions, significantly outperforming Z250 XT, Tetric N-Ceram, and Spectra Smart in specific comparisons. Nanohybrid composite, polymerization, degree of conversion.
树脂聚合不完全是牙科修复失败的主要原因。本研究旨在评估以下假设：四种纳米混合树脂的聚合距离和预热均会显著影响其转化率（DC）。
选择四种A2色纳米混合树脂：Filtek Z250 XT（3M公司）、Tetric N-Ceram（义获嘉公司）、Zafira（新美学公司）和Spectra Smart（登士柏公司）。选择这些树脂是因其成分各异。制作了48个圆盘（直径6毫米，厚度2毫米），其中24个圆盘预热至39°C。使用Bluephase N灯（义获嘉伟瓦登特公司）在1毫米和6毫米的距离下对所有圆盘进行40秒的聚合，该灯的工作波长为385 - 515纳米，光强为1200毫瓦/平方厘米。将聚合后的圆盘在37°C的蒸馏水中储存24小时，然后使用傅里叶变换红外光谱（FTIR）测量转化率。采用单因素方差分析和独立样本t检验进行统计分析。
预热至39°C的样品与室温下的样品在转化率方面未观察到统计学显著差异（> 0.05）。Zafira表现出最高的转化率，在所有组中均显著高于Z250 XT（< 0.005），且在表面上高于Tetric N-Ceram（< 0.05）。在特定条件下，Zafira和Spectra Smart之间也发现了显著差异（< 0.05）。1毫米和6毫米的聚合距离在转化率上未发现显著差异。整个树脂圆盘实现了均匀聚合。
将纳米混合树脂预热至39°C对其转化率没有统计学显著影响。即使在6毫米的固化距离下，使用高强度灯照射40秒也能获得可接受的转化率值。在测试的树脂中，Zafira在各种条件下表现出最高的转化率，在特定比较中显著优于Z250 XT、Tetric N-Ceram和Spectra Smart。纳米混合复合材料、聚合、转化率。
