Final answer:
Gutta percha is the most appropriate material to obdurate the root canal system of a primary tooth.
Step-by-step explanation:
The most suitable material for obturating the root canal system of a primary tooth is gutta-percha. Gutta-percha is a biocompatible and inert material widely used in endodontics to fill root canals. It is a natural rubber-based material that is easy to manipulate, making it suitable for the often smaller and more constricted root canals in primary teeth. Gutta-percha provides an effective seal, preventing the entry of microorganisms and helping to maintain the integrity of the tooth structure. Its biocompatibility and ease of use make it the material of choice for root canal obturation in primary teeth, supporting successful endodontic outcomes.