Effects of four kinds of ceramic casting alloys on P70S6k expression of human gingival fibroblasts

Chenggong HE; Keqiang HUANG; Zhigang LI; Rongjian SU

ABSTRACT

BACKGROUND:

It has been confirmed that some casting alloy can inhibit the activity of human gingival fibroblasts in vitro, which can be used for inducing apoptosis of human gingival fibroblasts (HGFs). However, the mechanism of this effect is poorly understood.

OBJECTIVE:

To investigate the effect of Ni-Cr, Co-Cr, Au and pure Ti ceramic alloys on the expression of P70S6k by HGFs in vitro.DESIGN, TIME AND

SETTING:

Grouping controlled experiments with the expression of P70s6k by HGFs in each group as observation objects. Experiments were performed at the Institute of Immunohistochemistry and Western blotting, Technology Building of Liaoning Medical University from July to October 2009.MATERIALS Ni-Cr, Co-Cr, Au and pure Ti ceramic alloys were processed by Shenzhen Mecodent Dental Laboratory Co., Ltd. The gingival from gingival neck of the first premolar (which goes to be extracted due to the need of orthodontic treatment) of teenager who was15 years old without any clinical disease was obtained, followed by the primary culture of HGFs. The fifth passage of cells in logarithmic phase were used to measure indexes.

METHODS:

Ni-Cr, Co-Cr, Au and pure Ti ceramic alloys were incubated in DMEM to prepare alloy leaching liquor, which were then added in HGF medium at 10% concentration. DMEM containing 10% fetal bovine serum was used in negative controls. MAIN OUTCOME

MEASURES:

The expression of P70S6k in each group was measured by Western Blotting following 72 hours of intervention with alloy leaching liquor.

RESULTS:

Western-blot results showed that there was no significant difference in the average gray value of P70S6k expression in Au, pure Ti ceramic alloys and control groups (P > 0.05). There was also no significant difference between Au ceramic alloys and pure Ti ceramic alloys groups or between Ni-Cr ceramic alloys and Co-Cr ceramic alloys groups. (P > 0.05), but Ni-Cr ceramic alloys group or Co-Cr ceramic alloys group showed significant difference compared with the Au, pure Ti ceramic alloys and control groups (P < 0.01).

CONCLUSION:

Au ceramic alloys and pure Ti ceramic alloys show that they have no obvious effect on the proliferation activity of HGFs. Ni-Cr and Co-Cr ceramic alloys showed an inhibitory effect on the proliferation activity of HGFs.