When I took Diane Townsend's workshop on abstract pastel work, she was "all about" PVA. I, for one, am happy that she turned us on to Poly Vinyl Acetate sizing.
When diluted somewhat with water, one can paint it right over that otherwise irreparable Boo Boo on your expensive pastel paper. Viola! New paper to work your pastel magic on!
Let's say you filled the tooth with two too many layers of extra soft pastel, and "she won't take anymore, Captain"...
Whip out your little bottle of archival sizing, and go to town on the repaired surface. DT likes the stuff so well, that she even states "pastel and PVA" as the medium on some of her works.
Alternative: Get out your .22, find a rabbit and shoot it. Skin the hide, and scrape the... (you get the idea)