Can advacal help increase bone density?

Maybe. If your intake of calcium is low, any calcium supplement will increase your bone density. The difference in raising bone density between the various calcium supplements is clinically not significant. There is a big difference in price and some supplements have been reported to contain lead. Better products will state that they have been independently tested for heavy metals.
Advacal. is an expensive calcium supplement . Eating calcium rich foods is the preferred. there are other better calcium products on the market.