The Lakers shared a pic of James -- who's gearing up for his 20th NBA season -- on social media minutes ago ... showing the 4-time NBA champ sporting his new bling.

In the pic, you see James' signature "LJ" logo -- which was created to go on all his shoes and apparel when he signed his deal with Nike -- etched on his tooth.

It's plausible Bron got the idea from his homie Odell Beckham Jr. ... who dropped $1.8 million on 13-carat diamond porcelain veneers in 2021.

The flashy wide receiver didn't stop there, though ... 'cause Odell then spent $5K to get diamonds implanted on his teeth -- which aren't removable!!

No word yet on who hooked LBJ up or how much it cost, but he just signed a 2-year, $97.1 million contract extension with the Lake Show ... so he can definitely afford it.