{HEAD ~ Treatment} with the mild etching compound may be carried out for {TAIL ~ about 15 seconds} to about 5 minutes, and is usually followed by a water rinse 
carried out for
{ HEAD ~ Treatment } with the mild etching compound may be carried out for { TAIL ~ about 15 seconds } to about 5 minutes , and is usually followed by a water rinse
HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH