Norevall L I, Marcusson A, Persson M
Department of Orthodontics, Umeå University, Sweden.
Eur J Orthod. 1996 Aug;18(4):373-84. doi: 10.1093/ejo/18.4.373.
Glass ionomer cement (GIC) has been suggested as an alternative to acrylic resin in bracket bonding because of its fluoride release. The aim of this clinical trial was to evaluate further the suitability of GIC as a bonding adhesive compared with an acrylic resin with regard to frequency of bracket failure, fracture modes and clean-up time after debonding. Two commercially available brackets were tested, one with a meshed foil base and the other with an integral base. A total of 60 patients, with a mean age of 13 years 7 months (range 10 years 8 months to 19 years 1 month) were consecutively selected. Brackets were bonded with a GIC (AquaCem, De Trey) and a no-mix diacrylate (Unite, Unitek Corp.) according to random assignment for each jaw. One group of patients (n = 30) was bonded with metal brackets with machine cut grooves in the base (DynaLock, Unitek). In the second group (n = 30) brackets with a meshed foil base (Unitwin, Unitek) were used. Bracket failure location during treatment was recorded as were fracture modes and time required for the clean-up of enamel surfaces at debonding. The frequency of failed brackets was higher with GIC (36 per cent) than with the diacrylate (15 per cent). Bracket failures for the cut groove base type occurred in 50 per cent with GIC and 23 per cent with the acrylic, meshed foil bases failed in 22 per cent GIC and in 7 per cent with the acrylic, respectively. The differences in failure between bracket types were significant at P < 0.001 for both bonding materials. Analysis of the fracture modes showed a small but noticeable difference in the strength of adhesion to the enamel surface, favouring GIC. Time required for the clean-up of enamel surfaces showed a significantly shorter debonding time for GIC. It is concluded that the use of a GIC for orthodontic bonding purposes considerably increases the risk of bond failures during treatment, especially in combination with a cut groove base type. One noticeable advantage with GIC bonding, however, is the shorter clean-up time for the enamel surfaces.
玻璃离子水门汀（GIC）因其能释放氟化物，被提议作为正畸托槽粘结中丙烯酸树脂的替代品。本临床试验的目的是，进一步评估与丙烯酸树脂相比，GIC作为粘结剂在托槽脱落频率、断裂模式以及脱粘后清理时间方面的适用性。测试了两种市售托槽，一种带有网状箔基底，另一种带有一体基底。连续选取了60例患者，平均年龄为13岁7个月（范围为10岁8个月至19岁1个月）。根据随机分配，为每个牙弓用GIC（AquaCem，De Trey）和一种免混合双丙烯酸酯（Unite，Unitek公司）粘结托槽。一组患者（n = 30）用基底带有机械切割槽的金属托槽（DynaLock，Unitek）粘结。第二组（n = 30）使用带有网状箔基底的托槽（Unitwin，Unitek）。记录治疗期间托槽脱落的位置、断裂模式以及脱粘时清理牙釉质表面所需的时间。GIC组托槽脱落的频率（36%）高于双丙烯酸酯组（15%）。对于切割槽基底类型的托槽，GIC组有50%发生脱落，丙烯酸酯组为23%；网状箔基底的托槽，GIC组有22%发生脱落，丙烯酸酯组为7%。两种粘结材料在不同托槽类型之间的脱落差异均具有显著性（P < 0.001）。对断裂模式的分析表明，GIC与牙釉质表面的粘结强度虽有细微但明显的差异，GIC更具优势。清理牙釉质表面所需时间显示，GIC的脱粘时间明显更短。结论是，将GIC用于正畸粘结目的会显著增加治疗期间粘结失败的风险，尤其是与切割槽基底类型的托槽联合使用时。然而，GIC粘结的一个显著优点是牙釉质表面的清理时间更短。
