Corrosion current and pH rise around titanium coupled to dental alloys

Abstract

Ra%'nholt G: Corrosion current and pH rise around titanium coupled to dental alloys. Scand J Dent Res 1988: 96: 466-72. Abstract -Corrosion reactions around titanium, usually considered biologically inert, might be provoked by coupling it galvanically with more eorrodible dental alloys. Experiments in vitro simulating tbe conditions of a titanium dental implant or root canal post coupled to an amalgam filling, demonstrated corrosion current densities up to 31 nA/cm', anodic pH values around the amalgam down to 2, and cathodic pH values around the titanium up to 10. The amounts of tin released by the enhanced corrosion of amalgam might contribute measurably to the daily intake of tbis element; tbe corrosion current generated reached values known to cause taste sensations. If the buffer systems of adjacent tissues in vivo are not able to cope with the high pH generated around the titanium, local tissue damage may ensue; this relationship is liable to be overlooked, as it leaves no evidence in the form of corrosion products.

Dental Implant Materials, Implant Design, and Role of Fea- A Brief Review

“…But some of the dental implant components like abutment, abutment screws, and various attachments are made of gold alloys, Co-Cr alloys and stainless steels. [14] Titanium is the material of choice for intraosseous applications because it has typical properties like high passivity, resistance to chemical dose. Also, it has ability to repair itself if damaged.…”

Galvanic Corrosion of Dental Amalgams in Contact with Titanium in Terms of Released Ions

“…Generally, the γ 2 phase dissolves following eq. (11): 11) 8Sn 7 Hg + 21O 2 + 42H 2 O + 28Cl − → 14Sn 4 (OH) 6 Cl 2 + 8Hg (11) This reaction indicates that the tin ions released from the γ 2 phase formed a complex salt with oxygen and chlorine and that mercury contained in the γ 2 phase formed mercury metal. Though part of the mercury metal changes to oxides and chlorides, the rest evaporates.…”

“…6) Ravnholt 7) measured galvanic current densities between amalgams and titanium in 1 mass% sodium chloride solution and showed that the conventional and the high-copper amalgams preferentially corroded as anodes compared to titanium as a cathode. Johansson and Bergmanet 8) measured the galvanic current densities of amalgams in contact with titanium in 0.9 mass% sodium chloride solution and reported that the galvanic current was always anodic on the conventional amalgam.…”

Full Issue PDF

“…A post and core assembly with unlike metals poses a potential for corrosion due to generation of a galvanic current (Pameijer, Glantz & Mobasherat, 1983;Ravnholt, 1988;Fernandes & Dessai, 2001). Non-noble metals, such as stainless steel, can promote corrosion or be subject to corrosion in non-biologic (Pickering, Beck & Fontana, 1962;McNally, 2004) and in biologic environments such as in the mouth (Silness, Gustavsen & Hunsbeth, 1979;Pameijer & others, 1983;Beague, 1992;Luu & Walker, 1992;Angell, 1999;Beech & Gaylarde, 1999;Kusy & others, 2002).…”

“…The research by Pickering and others (1962) and Hoke and others (1983) demonstrated stress forces and/or the wedging effect of metal corrosion in confined spaces. To avoid encouraging corrosion, it has been recommended that metals of differing electrochemical potential not be mixed, and that noble metal posts and cores made of the same metal be used (AngmarMånsson & others, 1969;Arvidson & Wróblewski, 1978;Ravnholt, 1988;Luu & Walker, 1992).…”