Back when I was in middle school, I read Jane Yolen's Pit Dragon Trilogy. I remember writing a report on the first one when I was in sixth grade. I've always loved fantasy and especially dragons and that series is one of the first ones I can remember from that category, if not the first.
When I joined goodreads a few years ago, I was adding the series and found that she had written a fourth book, 22 years after the previous one. I didn't 100% remember the series, but I checked out a few reviews and people said that there was a good recap so you didn't have to reread the first three.
And now I have theoretically finished the Pit Dragon Trilogy Chronicles. Yolen did tie up all the loose ends from the previous book and had a pretty final ending. I think there would be room to visit the planet again, but not with the same characters.
I liked the book overall, but it did seem rather slow at times and more of a means to a new ending for the series. If you have read the books, I would recommend picking this one as well.