Changes of serum nickel and chromium content at 6 months and 1 year after porcelain-fused-to-nichrome crown restoration: A comparison with healthy controls

Chunxiu LIU; Ruiping LI; Feng AN

ABSTRACT

BACKGROUND:

Although nickel and chromium are essential elements of human body, over high concentration of them will produce many adverse effects to human body, therefore biological safety of nichrome material for dental restoration deserves attention.

OBJECTIVE:

To observe the changes of nickel and chromium content at 6 months and 1 year after porcelain-fused-to-nichrome crown restoration, and compare to healthy controls to investigate the long-term safety of nichorme in oral cavity.DESIGN, TIME AND

SETTING:

A case-control observation was performed between January 2006 and December 2007 at the First Affiliated Hospital of Hebei North University, Zhangjiakou, Hebei Province, China.

PARTICIPANTS:

Sixty patients who visited Department of Stomatology, the First Affiliated Hospital of Hebei North University, between January and December 2006 were included in test group, including 28 male, 32 female, the mean age was 40 years. Each of them had 3 anterior maxillary teeth restored by porcelain-fused-to-nichrome crowns, without other metal fillings or protheses. Sixty healthy cases visited the hospital at the same time were used as control, including 30 male, 30 female, the mean ages was 39 years.

METHODS:

Fasting venous blood of participants in two groups was harvested sterilely at 6 months and 1 year after test group restoration, serum nickel and chromium content were determined using graphite furnace atomic absorption spectrometry.MAIN OUTCOME

MEASURES:

① Serum nickel content changes in test and control group. ②Serum chromium content changes in test and control group

RESULTS:

All cases were involved in result analysis. ① Serum nickel content changes in test and control group At 6 months postrestoration, there was no significant difference in serum nickel content between test group and control group (P>0.05). At 1 year after restoration, serum nickel content of test group was significantly higher than that of control group (P<0.05). ② Serum chromium content changes in test and control group There was no significant difference in chromium content between test and control group at 6 months and 1 year after test group restoration (P>0.05).

CONCLUSION:

Nickel and chromium released from porcelain-fused-to-nichrome crowns after restoration under oral environment, serum nickel content had an increasing tendency with the prolongation of restoration time, but in small quantity and within biosafety range, to identify whether the increasing tendency will increased continuously with the prolongation of restoration time needs long-term follow-up.