Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.
Experimental groups. (a) Group EX (Exacto glass fiber post). (b) Group EXR, (Exacto glass fiber post + two Reforpin accessories). (c) Group DT (D. T. Light quartz fiber post). (d) Group DTF (D. T. Light quartz fiber post + 2 Fibercone accessories)
