Co-author: Dental Irrigator. Health insurance plans seldom cover one’s dental needs; although some policies may also extend to dental procedures too, their number is pretty reduced. Therefore, the necessity of supplemental dental insurance is more than obvious. In the absence o a dental plan, one may have to pay a huge amount of money for dental services, which may be far beyond the limits of one’s normal budget. Even if the costs don’t get covered completely, yet, your financial participation in the various dental plans will count significantly in the eventuality of a treatment. Supplementary dental insurance does not represent an alternative or a substitute for primary insurance.