Department of Reconstructive Dentistry and Gerodontology, School of Dental Medicine, University of Bern, Bern, Switzerland.
Zahnarztpraxis Landmesser, Spiez, Switzerland.
J Esthet Restor Dent. 2024 Mar;36(3):453-459. doi: 10.1111/jerd.13136. Epub 2023 Sep 14.
To evaluate the effect of coffee thermocycling (CTC) on the surface roughness (R ) and stainability of denture base materials with different chemical compositions fabricated by using additive and subtractive manufacturing.
Disk-shaped specimens were additively (FREEPRINT denture, AM) or subtractively (G-CAM, GSM and M-PM, SM) fabricated from three pink denture base materials in different chemical compositions (n = 10). R was measured before and after polishing, while color coordinates were measured after polishing. Specimens were subjected to CTC (5000 cycles) and measurements were repeated. Color differences (ΔE ) after CTC were calculated. R among different time intervals within materials was evaluated by using repeated measures analysis of variance (ANOVA), while 1-way ANOVA was used to evaluate the R of different materials within each time interval and the ΔE values. Color coordinates within each material were compared by using paired samples t-tests (α = 0.05).
R before polishing was the highest for all materials (p < 0.001), while SM had its lowest R after CTC and AM had its lowest R after polishing (p ≤ 0.008). Before polishing, AM had the highest R among the materials (p < 0.001). After polishing, SM had higher R than AM (p < 0.001). After CTC, GSM had the lowest R (p ≤ 0.048). SM had the lowest (p ≤ 0.031) and AM had the highest (p < 0.001) ΔE . CTC decreased the a* and b* values of SM and AM (p ≤ 0.017), and increased the L* values of AM (p < 0.001).
Polishing significantly reduced the surface roughness of all materials. CTC did not increase the surface roughness of materials above the clinically acceptable threshold. Only AM had perceptible color change when previously reported threshold values for denture base materials were considered.
Tested denture base materials may have similar surface stability after coffee thermocycling. However, subtractively manufactured denture base materials may have improved color stability when subjected to long-term coffee consumption.
评估咖啡热循环（CTC）对使用添加剂和减法制造技术制造的不同化学成分义齿基托材料的表面粗糙度（R ）和染色性的影响。
从三种不同化学成分的粉色义齿基托材料（n=10）中分别采用加法（FREEPRINT 义齿，AM）和减法（G-CAM、GSM 和 M-PM、SM）制造圆盘状试件。抛光前后测量 R，抛光后测量颜色坐标。试件进行 CTC（5000 次循环），重复测量。计算 CTC 后的色差值（ΔE）。使用重复测量方差分析（ANOVA）评估材料内不同时间间隔的 R，使用单因素 ANOVA 评估每个时间间隔内不同材料的 R 和 ΔE 值。使用配对样本 t 检验比较每个材料内的颜色坐标（α=0.05）。
所有材料抛光前的 R 最高（p<0.001），而 SM 经 CTC 后 R 最低，AM 经抛光后 R 最低（p≤0.008）。抛光前，AM 是材料中 R 最高的（p<0.001）。抛光后，SM 的 R 高于 AM（p<0.001）。经 CTC 后，GSM 的 R 最低（p≤0.048）。SM 的 ΔE 最低（p≤0.031），AM 的 ΔE 最高（p<0.001）。CTC 降低了 SM 和 AM 的 a和 b值（p≤0.017），并增加了 AM 的 L*值（p<0.001）。
抛光显著降低了所有材料的表面粗糙度。CTC 未使材料的表面粗糙度超过临床可接受的阈值。只有 AM 在考虑义齿基托材料先前报道的阈值时，颜色才有明显变化。
测试的义齿基托材料在经过咖啡热循环后可能具有相似的表面稳定性。然而，当长期摄入咖啡时，减法制造的义齿基托材料可能具有更好的颜色稳定性。
