Effect of Saliva and Mucin-Based Saliva Substitutes on Fretting Processes of 316 Austenitic Stainless Steel

Joanna Mystkowska,Dawid Łysik,Marcin Klekotka

doi:10.3390/met9020178

Abstract

The paper presents the results of research of the fretting process of 316 austenitic stainless steel in the environment of natural saliva and mucin-based saliva preparations. The aim of the work was the evaluation of synthetic saliva preparations on biomaterial wear during fretting and fretting-corrosion. The fretting process, in the oscillatory micro-movements conditions, occurs in the joints of removable dentures, especially during the chewing phase. Fretting usually leads to the intensification of fatigue damage processes of materials. Experimental research, through rheological, fretting, fretting-corrosion, and microscopic analysis were performed. Tests indicate that natural saliva and saliva preparations are similar in terms of viscoelastic properties. The statistically significant proposed saliva solutions reduced the material wear in comparison to dry sliding, which is important in the case of people with saliva secretion problem. The addition of xanthan gum to the artificial saliva composition improved rheological characteristics, but on the other hand, led to an increase of secondary wear. It was confirmed by the volumetric wear of the samples and evaluation of energy dissipated during friction. Fretting-corrosion processes were explained by a mechanism related to crevice corrosion supported by friction.

Highlights

The loss of natural teeth impairs the functions of the tooth system, and disturbs chewing and speech
Mucins withthe each other at saliva, thisintermolecular property is determined by the presence of mucins[17,27]
The elastic moduli Gvalues observed for natural saliva (~3.5 Pa) were higher than for mucin‐based saliva preparations (~1 Pa for MX and ~0.2–0.3 for M)

Summary

Introduction

The loss of natural teeth impairs the functions of the tooth system, and disturbs chewing and speech. There is the need to use implants and prosthetic restorations. In the group of materials used in dentistry, they are austenitic steels, which as one of the first materials were used for implantation in the human body. The Association of British Society of Pediatric Dentistry (BSPD) recommends this steel for use on prosthetic constructions, elements of orthodontic appliances, and dental implants [1]. The main alloying elements of austenitic steels are chromium, nickel, and molybdenum. The amount of silicon and manganese is increased, and in some cases, nitrogen and niobium. Molybdenum in the amount of 3.3% mas Chromium content above 26% mas. and molybdenum in the amount of 3.3% mas

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