Is the word dentes the same in Brazilian and European Portuguese?

Yes

The difference between "dentes" in Brazilian Portuguese and Continental Portuguese is strictly phonetic. In Brazil, the unstressed final "e" is typically pronounced as a clear /i/ sound (sounding like "dên-chis"). In Portugal, this unstressed vowel is much more reduced, closed, or nearly silent, making the word sound shorter and more clipped.

Brazilian Portuguese Examples

1. Eu preciso escovar meus dentes antes de dormir. (I need to brush my teeth before sleeping.)
2. Os dentes dele são muito brancos. (His teeth are very white.)
3. O bebê está com os primeiros dentes nascendo. (The baby is getting its first teeth.)
4. Estou com uma dor de dente muito forte. (I have a very strong toothache.)
5. Ele caiu e quebrou um dos dentes. (He fell and broke one of his teeth.)

Continental Portuguese Examples

1. Tenho de escovar os dentes antes de dormir. (I must brush my teeth before sleeping.)
2. Ele tem os dentes muito brancos. (He has very white teeth.)
3. O bebé está a nascer os primeiros dentes. (The baby is growing its first teeth.)
4. Estou com uma dor de dentes terrível. (I have a terrible toothache.)
5. Ele caiu e partiu um dos dentes. (He fell and broke one of his teeth.)