Stomatologul folosește ața dentară.

In Romanian, the definite article is usually attached to the end of the noun, not written as a separate word.

So here:

• stomatologul = stomatolog
  • -ul = the dentist
• ața = ață
  • definite ending = the floss

This is one of the first big differences from English. Romanian says, in effect, dentist-the uses floss-the dental.

Stomatolog means dentist or more literally stomatologist. It is fully understandable and correct.

A few notes:

• stomatolog is a standard Romanian word
• in everyday speech, you may also hear dentist or medic dentist
• stomatologul is masculine singular definite: the dentist

So in this sentence, stomatologul is the subject.

Because -ul is a common masculine singular definite article in Romanian.

Examples:

• băiat → băiatul = the boy
• profesor → profesorul = the teacher
• stomatolog → stomatologul = the dentist

So the ending -ul is doing the job that the does in English.

Folosește is the 3rd person singular present tense of the verb a folosi = to use.

So:

• eu folosesc = I use
• tu folosești = you use
• el/ea folosește = he/she uses

Since stomatologul is singular, the verb is also singular: folosește.

It can mean either one, depending on context.

Romanian often uses the simple present where English might use either:

• uses
• is using

So Stomatologul folosește ața dentară could mean:

• The dentist uses dental floss
• The dentist is using dental floss

Context tells you which meaning is intended.

Because ața is the definite form of ață.

• ață = floss / thread
• ața = the floss / the thread

For many feminine nouns ending in -ă, the definite form changes the ending:

• casă → casa
• masă → masa
• ață → ața

So ața is the correct definite form here.

Because dentară is an adjective, and it must agree with ață, which is feminine singular.

The basic adjective is:

• dentar = dental

But it changes to match the noun:

• masculine singular: dentar
• feminine singular: dentară
• masculine plural: dentari
• feminine plural: dentare

Since ață is feminine singular, you get:

• ață dentară

Also, in Romanian, adjectives often come after the noun, so ață dentară is the normal order.

Yes, you can also say ață dentară.

The difference is roughly this:

• ață dentară = dental floss, floss in general, some dental floss
• ața dentară = the dental floss, or dental floss viewed as a specific/identified item

In practice, Romanian sometimes uses the definite form where English would use a more general expression. So this sentence is natural, especially as a simple teaching example.

Because ața dentară is a direct object, and Romanian normally does not use pe with inanimate direct objects.

The marker pe is mainly used with specific animate direct objects, especially people.

For example:

• Văd casa. = I see the house.
• Îl văd pe doctor. = I see the doctor.

Since ața dentară is a thing, not a person, there is no pe.

A rough pronunciation guide is:

sto-ma-to-LO-gul fo-lo-SESH-te A-tsa den-TA-rə

Useful sound notes:

• ș = sh as in shoe
• ț = ts as in cats
• ă = a schwa sound, like the a in about

So:

• folosește sounds like fo-lo-SESH-te
• ața sounds like A-tsa
• dentară ends with that short ă sound: den-TA-rə