I followed the 1 year old recommendation with my son. He totally freaked out and we even went to a pediatric dentist who was nice and prepared for it. I should have listened to my gut instinct and waited another year or two. He just wasn't ready yet. And my son has never been shy or afraid, he's always been very outgoing. But having someone put strange tools in your mouth is still very scarey for a small kid.
At age 2, he still freaked out. At age 3, he was scared, but didn't totally freak out. At age 4, he was totally fine with it. He did get a little freaked out when they told him that they would have to give him a shot in the mouth because they had to take out two cavities. They explained it more child friendly than that, but the smart kid he is, figured it out pretty fast anyways. But once they wrapped him in the velcro blanket that strapped him down from shoulder to knees, he was fine. Weird huh? But my kids have always loved being super swaddled. The more squished and uncomfortable it looked, the quicker they fell asleep, so I guess being "swaddled" at the dentist makes sense.
With my DD, she is more shy than her brother and more clingy. We've been taking her with us to the dentist when her brother goes, so she knows the whole office. She will go for her first official appointment this year in February (just a few months shy of her 3rd birthday) when her brother goes in for his 5 yo appointment.