A 4-year-old child was diagnosed with exacerbation of chronic periodontitis of tooth 85. X-ray shows destruction of the lamina dura of the dental follicle of tooth 45, a shadow in the bifurcation area of tooth 85, and pathologic resorption of 2/3 of the medial root. What treatment tactics would you choose?

Answer options

1. To extract tooth 85
2. To stop pain and inflammation, conduct impregnation treatment of root canals, and keep the tooth open until the natural replacement of the primary dentition occurs
3. To conduct endodontic and pharmacological treatment of the root canals of tooth 85 and apply occlusive dressing
4. To fill the root canals in one visit and perform periostotomy
5. To perform periostotomy and hemisection of the resorbed root