good line? flopped trips and make sucker boat on river

[bleu329]

Full Tilt 10/20 NL - 8 handed

Hero is in BB with 7 [img]/images/graemlins/diamond.gif[/img] 6 [img]/images/graemlins/diamond.gif[/img]

Its folded to weak/tight guy in MP who makes it $70
The guy after him is pretty loose preflop and very aggressive postflop. He calls
The SB also calls, whom just joined the table and I've never played before also calls.

I call, lets see a flop! Pot: $280

Flop: A [img]/images/graemlins/spade.gif[/img] 6 [img]/images/graemlins/spade.gif[/img] 6 [img]/images/graemlins/heart.gif[/img]

I bet $225. The original raiser quickly calls and the others fold. Pot: $730

Turn: 8 [img]/images/graemlins/diamond.gif[/img]

I bet $500. He calls in .4 seconds again. Hmmm.. Pot: $1730

River: A [img]/images/graemlins/diamond.gif[/img] F*CK!

I check. He now thinks for 5 seconds and bets $780. I fold.

Is there any way I can justify a call?