The Gunners boss saw bids for both Gonzalo Higuain and Luis Suarez fail during the summer, when France under-21 forward Sanogo arrived on a free transfer from Auxerre.
A deadline day loan move for Demba Ba from Chelsea never materialised, which meant Wenger decided against letting Bendtner leave as he needed cover for Olivier Giroud, who has scored in each of the four Barclays Premier League games so far.
Denmark international Bendtner subsequently issued a public statement in which he vowed to "give everything" to Arsenal this season.
With the 25-year-old - who was farmed out to Sunderland and then Juventus - close to full match fitness, the 6ft 3ins forward could be selected for the Capital One Cup tie at West Brom next week.
Wenger believes a fully-focused Bendtner, who was a prolific goalscorer in the Arsenal youth and reserve sides, can prove a useful addition to his first-team options.
"I will wait now until December to see what we need in the squad. We spoke about Bendtner, Sanogo, Giroud - if the three do well, I am in no need to buy any striker," the Arsenal manager said.
"Bendtner is a good striker. It is a fantastic opportunity for him.
"Honestly, he was supposed to go, but he stayed and once he stays you have to consider him as a full player of the squad. If he deserves to play in front of Giroud, he plays in front of Giroud. It is as simple as that.
"He lost his way a little bit, but he is not a bad boy. Bendtner is a good guy.
"He took the easy way a little bit, but now he realises there are some (signals) in your career when players think that is the moment for them. He has got the message (now) and has good self-esteem."
I don't think "good self-esteem" has ever been a problem for Bendtner.- drspaceman7