Does anybody know how a "spenddown" for DSS work?

I live in Connecticut, am on Social Security Disability, qualify for medicaid istance, but am always on what they call a "spenddown" where I have to pay a certain amount (or have accrued a certain amount) of medical bills before I can receive any aid. I need a lot of dental work very badly and wonder if I make arrangements with a dentist for the "spenddown" amount, if they'll cover the rest. I got an estimate for $18,000.00 for all the dental work I need, and wonder if they'll really pay the remainder. Does anyone know anything about how this works with DSS? I am in a real quandry, and can't get my worker on the phone and I have another appointment for a free consultation tomorrow with Aspen Dental and wish I had more information to bring with me. ANY istance will be extremely appreciated!