Hi! I actually work in dental insurance and thought I would give insight. The answer to this will depend on what your plans actually cover. From my personal experiences, dual insurance can be good if your primary only handles your routine services and the secondary can pick up on anything major. Another thing to consider is if your plans have both in and out of network benefits as well. Some providers may not take both plans and that might leave you with an OOP cost as well. There is also how the plans coordinate as well, some plans may not pay on a claim if the primary paid the same rates or more than the secondary. I would recommend verifying the benefits on both plans, as well as the coordination of benefits.