REINDEX or REBUILD the indexes of a table after truncating it and then repopulating it?

Is it necessary to REINDEX or REBUILD the indexes of a table after truncating it and then repopulating it? I have a table with approximately 3.5 million rows in Oracle. Every week new data is recharged, truncating the table and then loading the data. There are 2 or 3 indexes in the table. Should I delete and re-create the indexes or simply rebuild the ones I already have? , some indexed columns are encrypted with TDE. Thank you