This really is the first question to ask.  Let's walk through the three different types of dental insurances first.

HMO means that you choose a primary dentist or dental group up front and your services are handled solely by this provider or through referral to select specialists in a defined group.  Essentially, you have less choice of which dentist you can use and the providers tend to be more dental hygiene groups when you get your basis services done.  The trade off is that the premium is very inexpensive and there can be no cap on the amount the carrier will pay in a year's time.  HMO plans run about $10-30 per person on a monthly basis in the California individual market.

PPO means that you have larger list of dentist which you can use for lower out-of-pocket expense to you.  You can go off the list but you will pay more if you do so.  PPO plans offer more flexibility and a wider choice of dentists but they are also more expensive in terms of monthly premium.  You will also share more of the expense (usually coinsurance percentage or copay) than with an HMO and there is typically a cap of $1000-2,000 dollars per year after which, the carrier will no longer pay benefits.  This cap is a significant difference between PPO and HMO plans especially if you have larger dental bills in a year.  PPO plans run about $25-50 per person on a monthly basis.

Indemnity means that you have no network and the plan will pay out benefits (similar to PPO benefits) the same for all providers.  Indemnity plans tend to be more expensive but they work well if your dentist does not participate in any networks (which is more common these days).  The major health carriers have moved away from Indemnity dental plans just as they have medical.  There are some smaller carriers that still offer Indemnity dental benefits.  Indemnity plans run about $40-60 per person on a monthly basis.

What do dental insurance plans cover?

The dental benefits typically break down into three main areas. 

1) Preventative.  This typically includes cleanings and x-rays.  The dental plans will usually cover these services at 100% when in-network.  Sometimes there may be a small copay.  You can expect to pay more for out of network providers with a PPO.  With HMO dental plans, you will have to stay in the network in order to have any coverage. 

2) Minor Dental services.  This typically includes fillings and extractions etc.  As a rule of thumb, dental plans on the individual market will pay about 60-70% of these services (in-network).  There may be smaller waiting periods for such services of 3-6 months depending on the plan.  This means that you need to be on a dental plan for a period of time before they will cover such services.

3.  Major Dental services.  This typically includes services such as root canals and root planing etc.  Generally speaking, dental plans will pay around 50% of these services (in-network).  There are typically waiting periods (especially for PPO and Indemnity plans) of 12 months on average.

Between the network differences (HMO, PPO, or Indemnity) and the three general categories of services provided by California dental insurance plans, you have a good understanding of the various options on the market.

Other important concepts to help you understand your California dental insurance quote are:

Individual health insurance underwriting
The concept of health insurance
Understanding health insurance costs