Root completion of the mandibular first molar takes place by the age________?

Which of these teeth are highly sturdy and usually the last ones to be lost?

The pulp of first primary molar contains________?

Beginning of eruption of permanent tooth starts________?

Among the difference between teeth in the decidous and the permanent dentition is that________?

Rounded protuberances on the incisal edges of newly erupted permanent incisors are________?