Caria este atât de mare, încât stomatologul extrage măseaua.

Carie is the basic indefinite form of the noun, meaning a cavity or tooth decay.

Caria is the definite singular form, meaning the cavity / the decay.

Romanian usually adds the definite article to the end of the noun instead of using a separate word like the:

• carie = a cavity
• caria = the cavity

Because this is the fixed pattern atât de + adjective, which means so + adjective.

So:

• atât de mare = so big

This is a very common structure in Romanian when you want to express a result:

• atât de... încât... = so... that...

Because atât is used here with an adjective, mare.

A useful contrast is:

• atât de mare = so big
• atâta durere = so much pain

So:

• atât de
  • adjective/adverb
• atâta
  • noun

Even though caria is feminine, that does not change atât here, because atât is modifying mare, not directly modifying the noun.

Încât introduces the result clause. In English, it corresponds to that in the pattern so... that...

So the structure is:

• atât de mare, încât...
• so big, that...

It shows the consequence of the first part of the sentence.

Because încât introduces a subordinate clause of result, and Romanian normally separates that clause with a comma.

So the punctuation in:

• Caria este atât de mare, încât...

is standard and expected.

Stomatolog means dentist in the indefinite form.

Stomatologul means the dentist. Again, Romanian attaches the definite article to the end of the noun:

• stomatolog = a dentist
• stomatologul = the dentist

This -ul ending is a very common masculine singular definite article.

They are very close in meaning.

• stomatolog is a standard Romanian word for dentist
• dentist also exists and is commonly understood

So stomatologul and dentistul can both mean the dentist, although stomatolog can sound a bit more formal or technical.

Extrage is the 3rd person singular present form of the verb a extrage, meaning to extract or to remove.

Its present-tense forms include:

• eu extrag = I extract
• tu extragi = you extract
• el/ea extrage = he/she extracts

Here the subject is stomatologul, which is 3rd person singular, so extrage is the correct form.

Măsea is the indefinite form, meaning a molar.

Măseaua is the definite form, meaning the molar.

So:

• măsea = a molar
• măseaua = the molar

The ending looks a little different because Romanian noun forms can change when the definite article is attached. This is normal.

No. Măsea specifically means a molar.

If you want to say tooth in general, the usual word is dinte:

• dinte = tooth
• măsea = molar

So this sentence is specifically talking about a molar, not just any tooth.

Because măseaua is a direct object, but it is inanimate.

In Romanian, pe is often used before direct objects that are:

• people
• animate beings
• strongly specific or personal objects in certain contexts

But with an ordinary inanimate noun like măseaua, pe is normally not used.

So:

• stomatologul extrage măseaua = correct

Because mare has the same form for masculine and feminine singular.

So you get:

• un dinte mare = a big tooth
• o măsea mare = a big molar
• o carie mare = a big cavity

In the plural, it becomes mari:

• dinți mari
• măsele mari

The subject is stomatologul.

A learner might momentarily wonder whether măseaua could be the subject, but the meaning and structure show that:

• stomatologul = the one performing the action
• extrage = extracts
• măseaua = the thing being extracted

So măseaua is the direct object, not the subject.

Yes, Romanian word order is more flexible than English, but this sentence uses a very normal and neutral order.

The second clause:

• stomatologul extrage măseaua

follows the standard subject + verb + object pattern.

You may sometimes see different word orders in Romanian for emphasis, but the version in your sentence is the most straightforward one for learners.