Two ideas for you my friend. (Edit: Three ideas)
1. Nightmare Zone
Super smart Telepathic Dragon in a sensory deprivation tank? Of course that dragon's psychic power goes into overdrive.
When one sense is removed the other five rise to compensate. When five physical senses are removed the sixth psychic sense rises to compensate.
If the dragon was conscious it would turn all lesser life in a mile radius into willing thralls. Slave, open the restraints. And then they leave and fly away.
Unfortunately the dragon is doped up to its eyeballs. The psychic emanations come not from the Dragon's conscious mind but from its drug-induced nightmares.
The research lab becomes a Lovecraftian hellscape. No human in a mile radius can sleep. Then the walls start melting. Then they scratch out their own eyeballs. It's very scary. No one knows it's the dragon.
This perplexes people who monitor the lab remotely. Nothing strange appears on sensors. You have to be physically in the lab to be effected.
Eventually, by sheer accident, one of the demented people releases a dragon. That dragon releases the others. Problem solved.
2. Traitor
No matter what the restraints are, they can be overcome by simply asking nicely. And also offering a sizeable reward. Dragons are known for their hoards. If you help me escape you can choose one item from my hoard. And I will pretend I didn't see you take it.
Maybe the Dragon has gold and jewels in its hoard. They love that stuff.
Maybe the dragon has Maidens? Dragons love maidens. Maybe some of the maidens look like Geena Davis from The Fly?
In case you are worried, the dragon does not eat the maidens. The dragon simply collects the maidens like you would collect songbirds.
Maybe you don't like maidens? Well good news -- the Dragon is very bad at telling one human from another. So you might get lucky and find a maiden who looks exactly like Jeff Goldblum (also from The Fly).
3. Numerous Breath Weapons
Some dragons breath fire. Some breath clouds of steam. Some breath wasps. The dragon was observed to breath first and fitted with a fireproof muzzle. But the muzzle was not wasps-proof. The dragon excaped by breathing wasps instead of fire.