氮化碳与氮化钛及二氧化钛薄膜对正畸不锈钢弓丝表面摩擦性能的影响

Influences of carbon nitride (CN), titanium nitride (TiN) and titanium dioxide (TiO2) thin film on the frictional property of stainless steel used in orthodontic treatment

目的 通过在正畸不锈钢弓丝表面制备合金薄膜,探究不同种类合金镀膜对弓丝表面摩擦性能的影响.方法 将正畸不锈钢弓丝原料制成直径20 mm厚度1 mm的薄圆片,采用离子束辅助沉积法在其表面制备氮化碳薄膜、氮化钛薄膜,采用化学旋转涂覆法制备二氧化钛薄膜.使用多功能摩擦磨损试验机进行表面摩擦系数测定.使用三维白光干涉表面形貌仪进行表面粗糙度测定.将各组材料在不同氟浓度的人工唾液中浸泡3天,分别测定摩擦系数和表面粗糙度.将所得数据进行统计学分析和t检验.结果 不锈钢材料基底的摩擦系数为0.431±0.109,表面粗糙度(Surface roughness,Sa)为(0.175±0.008)μm;表面制备氮化碳(Carbon nitride,CN)膜后的摩擦系数显著降低,表面粗糙度没有明显变化;表面制备氮化钛(Titanium nitride,TiN)膜后的摩擦系数略有升高,表面粗糙度没有明显变化.与不锈钢基底相比,摩擦系数的差异均具有统计学意义(P<0.001).在不同浓度含氟人工唾液中浸泡后,TiN镀膜材料的表面摩擦系数增大;在无氟人工唾液中浸泡3天后,三种材料的表面粗糙度均无明显变化.二氧化钛(Titanium dioxide,TiO2)薄膜与基底结合强度较差,表面结构疏松,未测试出摩擦系数.结论 CN膜能够有效降低不锈钢弓丝的摩擦系数.其摩擦系数在含氟唾液中浸泡一段时间后仍能保持稳定,是一种用于改进不锈钢弓丝表面性能潜力较大的薄膜材料.

Objective To explore the frictional properties of stainless steel used in orthodontic treatment with surface modification of different alloy thin films.Methods CN Stainless steel which are used to made orthodontic wire are shaped to pieces with a diameter of 20mm and a 1mm thickness.Carbon nitride(CN) and Titanium nitride (TiN) film were deposited on these pieces by ion beam and Titanium dioxide (TiO2) film was deposited by sol-gel method.Frictional coefficients were measured by Universal Micro-Tribotester.Surface roughness(Sa) was measured by 3D white-light interfering profilometer.Each material was immersed in artificial saliva with Fluoride concentration of 0%,0.05% and 0.1% for 3 days,and was measured for Frictional coefficient and Sa.The results were calculated and compared by t-test.Results The friction coefficient of as-received stainless-steel samples is:stainless steel 0.431±0.109,and the surface roughness (Sa) is 0.175±0.008 μm.The friction coefficient declined significantly after deposition of CN film and increased slightly after deposition of TiN film,but the roughness after both processes remained stable.The differences of frictional coefficient between the coatings and original stainless steel pieces were significant (P<0.001).The differences of frictional coefficient between the coatings and substrate were significant (P<0.001).After immersion in different concentrations of artificial fluoride saliva,the friction coefficient of TiN film increased.After 3-day immersion in artificial non-fluoride saliva,no significance was found in Sa in all three materials.TiO2,with weak adhesive strength and porous surface,was not applicable for friction coefficient test.Conclusions CN thin film would decrease the friction coefficient of stainless steel wire and could maintain a relative stable friction coefficient after immersion in fluoride saliva,and it can be a potential material used in future improvement of archwire propertie.