Stand-alone dental plans are not affected by changing or losing other forms of insurance.
Some dental insurance plans provide coverage for major services (like root canals, braces) only after you have paid premiums for a certain length of time (ex: 12 or 18 months), so it may be wise to sign up sooner rather than later for your own dental insurance. If you happen to lose or drop your health insurance coverage, it will not affect the time you have invested in your stand-alone individual dental insurance plan.