Statement of problem

Xerostomia refers to the decrease in the quality and quantity of saliva. In denture wearers, xerostomia affects the retention of the denture because of lack of wettability of the denture base. However, which denture base resin materials are best wetted by artificial salivary substitutes is unclear.

Purpose

The purpose of this in vitro study was to determine the wetting properties of 3 different commercially available denture base resin materials with artificial salivary substitute by using contact angle measurements and to compare these properties before and after thermocycling.

Material and methods

A total 120 specimens were fabricated with 3 different denture base materials (n=40): heat-polymerized polymethylmethacrylate (DenTek), injection-molded nylon polyamide (Valplast), and microwave polymerized (VIPI WAVE). The advancing and receding contact angles were measured with a goniometer by using the WinDrop++ software program. The contact angle hysteresis was calculated from the advancing and receding contact angles values. The same specimens were subjected to thermocycling to measure the advancing and receding contact angles values. The comparative evaluation was carried out before and after thermocycling.

Results

The mean ±standard deviation contact angles of the microwave-polymerized material were (62.40 ±1.21 degrees) advancing contact angle, (32.12 ±0.66 degrees) receding contact angle, and (30.28 ±1.40 degrees) contact angle of hysteresis. It was followed by the injection-molded nylon polyamide material, whose mean ±standard deviation contact angle values were (68.57 ±1.72 degrees) advancing contact angle, (43.02 ±1.39 degrees) receding contact angle, (26.27 ±2.05 degrees) contact angle hysteresis and high impact strength heat-polymerized polymethylmethacrylate material, whose mean ±standard deviation contact angle values were (69.81 ±0.16 degrees) advancing contact angle, (41.90 ±1.02 degrees) receding contact angle, and (27.91 ±0.97 degrees) contact angle hysteresis. The statistical analysis showed significant differences among contact angle values of the microwave-polymerized material as compared with the heat-polymerized polymethylmethacrylate and injection-molded nylon polyamide materials (P<.001).

Conclusions

The microwave-polymerized material showed better wettability with artificial saliva substitute than heat-polymerized polymethylmethacrylate and injection-molded nylon polyamide.

中文翻译：

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热循环前后三种含唾液替代品的义齿基托材料的比较评价：体外研究

问题陈述

口干症是指唾液的质量和数量下降。在义齿佩戴者中，由于义齿基托缺乏润湿性，口干会影响义齿的固位。然而，人工唾液替代品最能润湿哪种义齿基托树脂材料尚不清楚。

目的

这项体外研究的目的是通过使用接触角测量来确定 3 种不同的市售义齿基托树脂材料与人工唾液替代物的润湿特性，并比较热循环前后的这些特性。

材料与方法

总共 120 个样本由 3 种不同的义齿基底材料 (n=40) 制成：热聚合聚甲基丙烯酸甲酯 (DenTek)、注塑尼龙聚酰胺 (Valplast) 和微波聚合 (VIPI WAVE)。前进和后退接触角通过使用WinDrop++软件程序用测角仪测量。接触角滞后由前进和后退接触角值计算。对相同的样品进行热循环以测量前进和后退接触角值。在热循环之前和之后进行对比评价。

结果

微波聚合材料的平均±标准偏差接触角是(62.40±1.21度)前进接触角、(32.12±0.66度)后退接触角和(30.28±1.40度)滞后接触角。其次是注塑尼龙聚酰胺材料，其平均±标准偏差接触角值为（68.57±1.72度）前进接触角，（43.02±1.39度）后退接触角，（26.27±2.05度）接触角滞后高冲击强度热聚合聚甲基丙烯酸甲酯材料，其平均±标准偏差接触角值为（69.81±0.16度）前进接触角，（41.90±1.02度）后退接触角和（27.91±0.97度）接触角滞后。P <.001）。

结论

与热聚合聚甲基丙烯酸甲酯和注塑尼龙聚酰胺相比，微波聚合材料对人工唾液替代品显示出更好的润湿性。