Portugal, who meet the Danes on Wednesday after an opening 1-0 loss to Germany, have only won one of their last four competitive games against the Scandinavians.
In Euro 2012 qualifiers, Denmark and Portugal beat each other at home and Bento was coach for both matches.
"Each team has won one game. Our conviction is that if we have won one time already we can win another time, that's what we're confident of," Bento told reporters.
"To do that we'll have to become more efficient. The ball just has to go into the goal."
Portugal have scored just once in the last four games and showed little real sign of breaking that sorry record against Germany when their best chance fell to a defender.
"Tomorrow we will face a very strong opponent... Denmark is in a more comfortable position with less pressure. They have very strong counter-attacks," said Bento.
"We have even more pressure than we had before the game against Germany but it's not the first time that we are in such a situation," he added, noting that Portugal lost the first game at Euro 2004 and went on to reach the final.
Bento, who said he continued to think his team could reach the quarter-finals, dismissed media reports of a rift with winger Cristiano Ronaldo, who tore off his armband as he left the pitch after the German game.
"Every player has his own reaction in such situations in a game with such stress... from a certain point of view I understand such reactions," the coach said.
The German defence shackled Ronaldo well.
"We created good chances but we will have to work on just taking these chances and to score. I hope the team will finally succeed in scoring," said striker Helder Postiga, who has hit the net 19 times in 50 internationals.
"If we create opportunities of course we will score sooner or later, I'm absolutely convinced of that."
Postiga's place is under threat from both Hugo Almeida and promising youngster Nelson Oliveira.
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