Surface, Microstructural, and Mechanical Characterization of Abutment Screws With Modified Surface Characteristics

This study aimed to characterize the microstructural, mechanical, and surface properties of abutment screws with modified surface characteristics.

Five anodized abutment screws of different coloration (green, purple, yellow, blue, brown), one Diamond-like carbon (DLC)-coated screw, one gold-alloy screw, one gold-coated screw, and one uncoated screw were used. Surface roughness parameters (S_a, S_q, S_sk, S_ku, S_pk, S_k, and S_vk) were assessed by an optical profiler. Microstructural observations and elemental analysis were conducted with a scanning electron microscope (SEM) equipped with energy dispersive X-ray detector (EDX). Martens Hardness (HM) and Indentation Elastic Modulus (E_IT) were evaluated using Ιnstrumented Ιndentation Testing (IIT) employing a nanoindentation testing device. One-way ANOVA and Tukey post hoc tests were performed for statistical analyses (a = 0.05).

SEM-EDX analysis demonstrated differences in microstructure and elemental composition on the bulk and the surface of abutment screws tested. Statistically significant differences were found for all surface roughness parameters and mechanical properties tested. The green anodized screw demonstrated significantly higher S_a, S_q, S_pk, and S_{v k} values, while the gold-coated screw had significantly higher HM and E_IT.

The examined abutment screws displayed significant variations in the properties assessed, indicating that these differences may lead to variations in their clinical performance.