Final answer:
The most conservative restoration after endodontic therapy on a maxillary molar with an MOD alloy is an MOD onlay, which is less invasive than a full crown but offers more support than an inlay or composite resin.
Step-by-step explanation:
After endodontic therapy is completed on a maxillary molar with an MOD alloy, the most conservative final restoration indicated would likely be an MOD onlay. An MOD onlay covers the occlusal and proximal surfaces of the tooth but conserves more tooth structure than a full crown because it does not cover the entire surface of the tooth. This option allows for preservation of tooth tissue while still providing the necessary support and stability after root canal treatment. An MOD inlay could also be considered somewhat conservative but does not provide as much cuspal protection as the onlay. A composite resin could also be a conservative choice, but it may not offer the same level of durability as an onlay, especially on a tooth that has undergone significant reconstruction like one requiring endodontic therapy.