通过使用简单的型壳涂料技术改善磷酸钙粘结剂包埋铸造的商用纯钛边缘适合性。

Department of Dental of Materials and Prosthodontics, Sao Paulo State University (UNESP), School of Dentistry, Araraquara, Sao Paulo, Brazil.

J Prosthet Dent. 2012 Jul;108(1):51-7. doi: 10.1016/S0022-3913(12)60105-X.

STATEMENT OF PROBLEM

Coatings of zirconite, Y(2)O(3) or ZrO(2) on wax patterns before investing in phosphate-bonded investments have been recommended to reduce the reaction layer in titanium castings, but they are not easily obtainable. Spinel-based investments are relatively stable with molten titanium and could be used as coatings to improve the quality of castings made with those investments.

PURPOSE

The purpose of this study was to evaluate the effect of pattern coating with a commercial spinel-based investment before investing in 1 of 3 phosphate-bonded inves tments on the marginal coping fit and surface roughness of commercially pure titanium castings.

MATERIAL AND METHODS

Ten square acrylic resin patterns (12 × 12 × 2 mm) per group were invested in the phosphate-bonded investments Rematitan Plus (RP), Rema Exakt (RE), and Castorit Super C (CA) with or without a coating of the spinel-based investment, Rematitan Ultra (RU). After casting, the specimens were cleaned and the surface roughness was measured with a profilometer. Copings for dental implants with conical abutment were invested, eliminated, and cast as previously described. The copings were cleaned and misfit was measured with a profile projector (n=10). For both tests, the difference between the mean value of RU only and each value of the phosphate-bonded investment was calculated, and the data were analyzed by 2-way ANOVA and Tukey's HSD test (α=.05). In addition, the investment roughness was measured in bar specimens (30 × 10 × 10 mm), and the data (n=10) were analyzed by 1-way ANOVA and Tukey's HSD post hoc test (α=.05).

RESULTS

Two-way ANOVA for casting surface roughness was significant because of the investment, the coating technique, and the interaction between variables. One-way ANOVA was performed to prove the interaction term, and Tukey's post hoc test showed that RP with coating had the lowest mean, while RP had the highest. CA with coating was not different from RP with coating or CA without coating. RE with coating was similar to CA, while RE was different from all groups. For coping marginal fit, the 2-way ANOVA was significant for the investment, the coating technique, and the interaction between variables. The interaction was analyzed by1-way ANOVA and Tukey's HSD test that showed no significant difference among the coated groups, which had better marginal fit than the groups without coating. Among the groups without coating, CA had significant lower marginal misfit than RP, while RE was not different from CA and RP. For the investment surface roughness, the 1-way ANOVA was significant. CA and RU were smoother than RE and RP (P<.001).

CONCLUSIONS

The coating technique improved the quality of castings fabricated with phosphate-bonded investments.

问题陈述

在磷酸盐结合型包埋料中对蜡型进行氧化锆、Y(2)O(3)或 ZrO(2)涂层处理，以减少钛铸件中的反应层，这已得到推荐，但这些涂层难以获得。尖晶石基包埋料与熔融钛相对稳定，可用作涂层，以改善使用这些包埋料制作铸件的质量。

目的

本研究的目的是评估在 1 种磷酸盐结合型包埋料中进行包埋之前，用商业尖晶石基包埋料对蜡型进行涂层处理，对商业纯钛铸件的边缘覆盖拟合和表面粗糙度的影响。

材料和方法

每组 10 个方形丙烯酸树脂蜡型（12×12×2mm），分别用磷酸盐结合型包埋料 Rematitan Plus（RP）、Rema Exakt（RE）和 Castorit Super C（CA）进行包埋，或在包埋前用商业尖晶石基包埋料 Rematitan Ultra（RU）进行涂层处理。铸造后，用轮廓仪测量试样的表面粗糙度。用锥形接台的牙种植体对冠进行包埋、去除和铸造，方法如前所述。对冠进行清洗，用轮廓投影仪测量失配度（n=10）。对于这两种测试，计算 RU 仅有的平均值与每个磷酸盐结合型包埋料值之间的差值，并通过双因素方差分析和 Tukey 的 HSD 检验（α=.05）对数据进行分析。此外，用 30×10×10mm 的棒状标本测量包埋料的粗糙度，对 10 个数据（n=10）进行单因素方差分析和 Tukey 的 HSD 事后检验（α=.05）。

结果

由于包埋料、涂层技术和变量之间的相互作用，对铸造表面粗糙度的双因素方差分析是显著的。进行了单因素方差分析来证明交互项，Tukey 的事后检验显示，有涂层的 RP 具有最低的平均值，而 RP 具有最高的平均值。有涂层的 CA 与 RP 无涂层或 CA 无涂层的平均值没有差异。有涂层的 RE 与 CA 相似，而 RE 与其他组不同。对于边缘覆盖拟合度，由于包埋料、涂层技术和变量之间的相互作用，双因素方差分析是显著的。对交互作用进行了单因素方差分析和 Tukey 的 HSD 检验，结果显示涂层组之间没有显著差异，涂层组的边缘拟合度优于无涂层组。在无涂层组中，CA 的边缘不匹配显著低于 RP，而 RE 与 CA 和 RP 无差异。对于包埋料表面粗糙度，单因素方差分析是显著的。CA 和 RU 比 RE 和 RP 更光滑（P<.001）。