Corrosion resistance of three orthodontic brackets: a comparative study of three fluoride mouthwashes

Abstract

In the present study, three types of orthodontic brackets were investigated: cobalt-chromium (CoCr), iron-chromium-nickel (FeCrNi) and titanium (Ti) based. Their corrosion resistance was compared with that of platinum (Pt), which was chosen as the reference material because of its excellent electrochemical properties. The test solutions were Elmex, Meridol and Acorea fluoride mouthwashes. Fusayama Meyer artificial saliva was used as the reference solution. The corrosion resistance of the different brackets in the three mouthwashes was assessed electrochemically to determine the corrosion potential and corrosion current density, and polarization resistance values were then calculated. A scanning electron microscopic (SEM) study and an analysis of released metal ions confirmed the electrochemical studies. The results showed that the bracket materials could be divided into two groups: Ti and FeCrNi in one, and CoCr, which has properties close to those of Pt, in the other. Similarly, two groups of electrolytes were identified: Elmex and Acorea mouthwashes in one group, and Meridol mouthwash in the second group. The results indicate that because of the risk of corrosion Meridol mouthwash should not be prescribed for patients wearing Ti or FeCrNi-based orthodontic brackets.

Assessment of Ions released from Three Types of Orthodontic Brackets immersed in Different Mouthwashes: An in vitro Study

“…In an acidic environment, corrosion could easily occur even with low fluoride concentrations; 32 pitting type of corrosion is caused by anions, such as chloride and fluoride ions which attack the protective oxide layer. 33 Manganese and copper were the highest in ALO mouthwash, although these results disagreed with Singh 34 who found that ALO has inhibition efficiency of corrosion lying between 22 and 73% at different concentrations; however, there are several possible explanations for these results. It seems possible due to Cu ion percentage in the stainless steel alloy of bracket and the chemical composition of mouthwash.…”

Metal ion release from silver soldering and laser welding caused by different types of mouthwash

“…This is considered a consequence of the release of the trace amounts of silver and copper present in some commonly used solutions, tubes, bottles, bottle caps, and clips. Although there are several studies that have investigated corrosion on orthodontic appliances caused by mouthwashes, 19,[28][29][30] there are not many studies that have investigated the effects of mouthwashes on different soldering applications. Our finding is that the greatest amount of metal ion release occurs in NaF + alcohol containing mouthwashes and may contribute to both the literature and to clinical practice.…”

“…25,26 It has been reported that mouthwashes increase the risk of corrosion and cause the release of some metals from the surface of orthodontic appliances. [27][28][29][30] There are no prior studies in the literature that investigate the relationships between various mouthwashes, metal ion release, and various soldering methods. The aim of the present study was to compare the release of nickel, chromium, iron, silver, and copper ions; the corrosion rate; and the amount of corrosion for two different soldering methods used in the preparation of orthodontic appliances-laser welding and silver soldering-in three different mouthwash solutions.…”

Corrosion behavior of pure titanium in artificial saliva solution

“…Moreover, different techniques are currently being used to obtain coatings of biotolerable materials with mechanical strength and with a bioactive layer [11,12]. Coatings can be produced, for example, by ion sputtering, plasma spraying, sol-gel, electrolysis, and biomimetic methods [6].…”