Abstract：
OBJECTIVE: To evaluate the effect of the deterioration of computer aided design/computer aided manufacturing (CAD/CAM) burs during zirconia milling, on surface roughness, contact angle, and fibroblast viability.
METHODS: Ceramic blocks were milled and 75 ceramic disks (8 × 1.5 mm) made and allocated into three groups (n = 25): G1-brand new 2L and 1L burs, G2-2L bur at the end of lifetime and brand new 1L bur and G3-both burs at the end of their lifetimes. Roughness (Ra, Rq, and Rz) was evaluated using a 3D optical profilometer, the contact angle by the sessile drop method and the cell viability of the mouse NIH/3T3 fibroblast, using the Alamar Blue assay at intervals of 24, 48, and 72 h (ISO 10993-5). Data were analyzed by one-way ANOVA and Kruskal-Wallis tests (p ≤ 0.05).
RESULTS: Roughness increased as the burs deteriorated and G3 (0.27 ± 0.04) presented a higher value for Ra (p < 0.001). The highest contact angle was observed in G3 (86.2 ± 2.66) when compared with G1 (63.7 ± 12.49) and G2 (75.3 ± 6.36) (p < 0.001). Alamar Blue indicated an increase in cell proliferation, with no significant differences among the groups at 24 and 72 h (p > 0.05).
CONCLUSIONS: The deterioration of the burs increased the surface roughness and decreased the wettability, but did not interfere in cell viability and proliferation.
CONCLUSIONS: The use of custom zirconia abutments represents an effective strategy for single crowns restorations. Our findings suggest that these abutments can be efficiently milled using CAD/CAM burs within their recommended lifetime.
METHODS: Ceramic blocks were milled and 75 ceramic disks (8 × 1.5 mm) made and allocated into three groups (n = 25): G1-brand new 2L and 1L burs, G2-2L bur at the end of lifetime and brand new 1L bur and G3-both burs at the end of their lifetimes. Roughness (Ra, Rq, and Rz) was evaluated using a 3D optical profilometer, the contact angle by the sessile drop method and the cell viability of the mouse NIH/3T3 fibroblast, using the Alamar Blue assay at intervals of 24, 48, and 72 h (ISO 10993-5). Data were analyzed by one-way ANOVA and Kruskal-Wallis tests (p ≤ 0.05).
RESULTS: Roughness increased as the burs deteriorated and G3 (0.27 ± 0.04) presented a higher value for Ra (p < 0.001). The highest contact angle was observed in G3 (86.2 ± 2.66) when compared with G1 (63.7 ± 12.49) and G2 (75.3 ± 6.36) (p < 0.001). Alamar Blue indicated an increase in cell proliferation, with no significant differences among the groups at 24 and 72 h (p > 0.05).
CONCLUSIONS: The deterioration of the burs increased the surface roughness and decreased the wettability, but did not interfere in cell viability and proliferation.
CONCLUSIONS: The use of custom zirconia abutments represents an effective strategy for single crowns restorations. Our findings suggest that these abutments can be efficiently milled using CAD/CAM burs within their recommended lifetime.
摘要：
目的：评估氧化锆铣削过程中计算机辅助设计/计算机辅助制造（CAD/CAM）毛刺劣化的影响，关于表面粗糙度，接触角,和成纤维细胞活力。
方法：研磨陶瓷块，制成75个陶瓷盘（8×1.5mm），并分为三组（n=25）：G1-全新的2L和1L毛刺，G2-2Lbur在寿命结束时，全新的1Lbur和G3-都在寿命结束时。粗糙度(Ra,Rq,和Rz）使用3D光学轮廓仪进行评估，无柄滴法的接触角和小鼠NIH/3T3成纤维细胞的细胞活力，以24、48和72小时的间隔使用AlamarBlue测定法(ISO10993-5)。数据通过单因素方差分析和Kruskal-Wallis检验进行分析(p≤0.05)。
结果：粗糙度随着毛刺的恶化而增加，而G3（0.27±0.04）呈现更高的Ra值（p<0.001）。与G1（63.7±12.49）和G2（75.3±6.36）相比，G3（86.2±2.66）的接触角最高（p<0.001）。AlamarBlue表明细胞增殖增加，24h和72h组间无显著差异(p>0.05)。
结论：毛刺的劣化增加了表面粗糙度，降低了润湿性，但不干扰细胞活力和增殖。
结论：使用定制氧化锆基台代表了单冠修复的有效策略。我们的发现表明，可以在推荐的使用寿命内使用CAD/CAM毛刺有效地铣削这些基台。
方法：研磨陶瓷块，制成75个陶瓷盘（8×1.5mm），并分为三组（n=25）：G1-全新的2L和1L毛刺，G2-2Lbur在寿命结束时，全新的1Lbur和G3-都在寿命结束时。粗糙度(Ra,Rq,和Rz）使用3D光学轮廓仪进行评估，无柄滴法的接触角和小鼠NIH/3T3成纤维细胞的细胞活力，以24、48和72小时的间隔使用AlamarBlue测定法(ISO10993-5)。数据通过单因素方差分析和Kruskal-Wallis检验进行分析(p≤0.05)。
结果：粗糙度随着毛刺的恶化而增加，而G3（0.27±0.04）呈现更高的Ra值（p<0.001）。与G1（63.7±12.49）和G2（75.3±6.36）相比，G3（86.2±2.66）的接触角最高（p<0.001）。AlamarBlue表明细胞增殖增加，24h和72h组间无显著差异(p>0.05)。
结论：毛刺的劣化增加了表面粗糙度，降低了润湿性，但不干扰细胞活力和增殖。
结论：使用定制氧化锆基台代表了单冠修复的有效策略。我们的发现表明，可以在推荐的使用寿命内使用CAD/CAM毛刺有效地铣削这些基台。
