Johnny Sexton, the Ireland captain, and centre Garry Ringrose, who both missed the round-three win in Italy, are also back in the side after recovering from injuries.
Furlong's return to fitness following a calf problem is a welcome boost for Ireland coach Andy Farrell after backup prop Finlay Bealham suffered a tournament-ending knee injury in a 34-20 victory in Rome last month.
The 30-year-old Furlong has not played competitively since Leinster's 38-29 victory over Ulster on December 3.
But despite a 99-day gap between appearances, Farrell is confident Furlong will be ready to help tournament leaders Ireland continue their quest for what would just be a fourth Grand Slam.
"Some players can and some players can't and he's across his detail like no other," Farrell said of Furlong.
"Tadhg doesn't have to tear himself apart mentally to try and make sure that he gets up to speed because he's already figured it out."
Farrell, a former England dual-code international, added: "He's one of those that probably when he's driving the car, or sat in his room, or having a bit of food or whatever, he's probably thinking about the game anyway so when it comes to training it's all boxed off.
"He brings confidence to the team by how he prepares and that gives us confidence to know that he's ready to play.
"He's a world-class prop and a great leader and when you look around the changing room there are certain players that give a sense of confidence whether they're playing or not and he's one of them.
"Tadhg's nothing to lose. He just needs to be himself, he just needs to go out there and enjoy it."
Ireland are the only team left in the tournament that can complete a Grand Slam.
A win in Edinburgh would set them up for a March 18th tilt at a clean sweep against England in Dublin.
Ireland (15-1): Hugo Keenan; Mack Hansen, Garry Ringrose, Bundee Aki, James Lowe; Johnny Sexton (capt), Conor Murray; Caelan Doris, Josh van der Flier, Peter O'Mahony; James Ryan, Iain Henderson; Tadhg Furlong, Dan Sheehan, Andrew Porter
Replacements: Ronan Kelleher, Cian Healy, Tom O'Toole, Ryan Baird, Jack Conan, Jamison Gibson-Park, Ross Byrne, Robbie Henshaw
Coach: Andy Farrell (ENG)
