Final answer:
To answer the question, the first statement is false and the second is true, meaning external resorption is more common than internal resorption, and internal resorption can occur with a vital pulp (d).
Step-by-step explanation:
The question posed pertains to the phenomena of internal and external resorption in teeth. Specifically, it addresses whether internal resorption is more common than external resorption and if internal resorption occurs in the presence of a vital pulp. To clarify, the correct answer is that the first statement is false; the second is true (d).
External resorption is more commonly encountered than internal resorption. Internal resorption does indeed occur when the pulp of the tooth is vital and has the capacity to initiate an inflammatory response, usually as a reaction to injury or trauma.
Exploring further, teeth are structurally composed of a crown and a root, with the crown being protected by enamel, and the root containing the pulp canal. Inside the pulp canal lies the pulp tissue, rich in nerves and blood vessels, along with connective tissues.
When the tooth is compromised, such as with dental caries, and the decay extends to the pulp, a root canal procedure may be necessary to remove the infected tissue and prevent the spread of infection leading to abscesses.
The concepts of bone resorption and formation, mentioned within the context of osteoblast and osteoclast functions, relate to the maintenance and turnover of bone tissue, but are important to understand as they provide a backdrop to the biological processes of tooth resorption.
In the context of the question, understanding the roles of osteoclasts (bone resorbing cells) facilitates comprehension of the resorption process within the teeth.