Whats the difference between High and Standard Option Dental Insurance?

I have been looking at High and Standard Option Dental Plans. (I work for the federal government). These plans seem to pay about the same for pretty much the dental procedures. Am I missing something? Whats the difference between a high and standard option plan?
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For the MetLife Federal dental plan.. the high option has a $3,000 calendar year benefit, standard is $1,200. There is no deductible when staying in-network, and the percentages are.. For preventive or class A both plans offer 100% coverage. For basic dental work, or class B.. high option you pay 30%, standard is 45%. And for major services or class C.. high you pay 50%, standard is 65%. These are all based on the in-network discounted rates. You also have out-of-network coverage.. but at higher percentages. I'd check with your benefits rep, for any detailed or exact information
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