Surface roughness of different contraceptive vaginal rings: evaluation by scanning electron microscope (SEM)

Abstract

Objective: The aim of the study was to evaluate whether the compositions of the ethylene vinyl acetate (EVA) membrane of two different contraceptive vaginal rings could influence the surface roughness, which is associated with the possible accumulation of vaginal biomass on the rings during use.

Methods: We measured and compared the surface roughness of unused vaginal rings, NuvaRing and Ornibel, using a scanning electron microscope (SEM) and dedicated software that can convert SEM images into 3D models. Average roughness (Ra), average quadratic roughness (Rq) and mean height of the irregularities at 10 points (Rz) were calculated.

Results: Different thicknesses of the EVA membranes between the two rings were noted. No significant differences were found between the two rings in the three evaluated values of surface roughness (NuvaRing vs Ornibel, respectively: Ra, 1.53 ± 0.14 vs 1.61 ± 0.14 µm, p = 0.141; Rq, 2.03 ± 0.25 vs 2.07 ± 0.16 µm, p = 0.688; Rz, 11.4 ± 3.1 vs 11.4 ± 2.4 µm, p = 0.987).

Conclusion: The different composition of the vaginal rings’ EVA membrane is not associated with different surface roughness. Ornibel is equivalent to NuvaRing in terms of surface roughness, despite the different composition of the membrane polymers.

摘要：

目的：本研究的目的是评估两种不同避孕环的乙烯-醋酸乙烯酯(EVA)膜的组成是否会影响避孕环的表面粗糙度, 这与使用过程中避孕环上可能积累的阴道生物量有关。

方法：我们使用扫描电子显微镜(SEM)和可以将SEM图像转换为3D模型的专用软件, 测量并比较未使用的避孕环、NuvaRing 及 Ornibel的表面粗糙度。计算平均粗糙度(Ra)、平均二次粗糙度(Rq)和10个点的平均高度(Rz)。

结果：值得注意的是：这两种避孕环之间的EVA膜厚度不同, 而两种环表面粗糙度的3个评估值差异无统计学意义(分别为：Ra, 1.53±0.14vs1.61±0.14 mm, p=0.141；Rq, 2.03±0.25vs2.07±0.16 mm, p=0.688；Rz, 11.4±3.1vs11.4±2.4 mm, p=0.987)。

结论：避孕环EVA膜成分的不同与其表面粗糙度无关。尽管Ornibel和NuvaRing的膜聚合物组成不同, 但它们在表面粗糙度方面相差不多。

Keywords:

• Contraception
• NuvaRing
• Ornibel
• roughness
• surface
• vaginal health
• vaginal ring

Disclosure statement

Giovanni Grandi has been a lecturer, consultant and member of advisory boards for Bayer AG, Teva/Theramex, Sandoz/Novartis, MSD, Effik Italia, Exeltis Italia and Sanofi-Aventis. All other authors declare that there is no duality of interest associated with their contribution to this manuscript.

Additional information

Funding

The measurement costs were paid by Exeltis Italia (Milan, Italy) to JDentalCare (Modena, Italy), which owns the SEM instruments. JDentalCare is an independent company, operating in another business (implant dentistry).