The dictionary is not sealed, so if you need the appropriate subtype, do
class DataDictionary<K, V> : Dictionary<K,V>
{
}
And one more option:
class DataDictionary<K, V>
{
private Dictionary<K,V> _data;
}
This gives you more freedom in your own type of design.
And if you meant "How to eliminate type parameters", use something like:
class DataDictionary : Dictionary<string, int>
{
}