Geraham itu perlu mahkota gigi.

In Indonesian, demonstratives like ini and itu usually come after the noun.

• geraham itu = that molar / the molar
• mahkota gigi itu = that dental crown

So this is normal Indonesian word order, even though English puts that before the noun.

It can mean either, depending on context.

Itu literally means that, but in real usage it often also works like the when referring to something already known in the conversation. So geraham itu could be understood as:

• that molar
• the molar

The exact translation depends on the situation.

Geraham means molar, the large tooth at the back of the mouth used for chewing.

You may also see gigi geraham, which literally means molar tooth, but geraham by itself is very common and natural.

It is most naturally understood as singular here: that/the molar.

Indonesian nouns usually do not change form for singular vs. plural. Number is often understood from context. If a speaker wanted to make it clearly plural, they might say something like:

• geraham-geraham itu = those molars
• beberapa geraham = several molars

Perlu means to need or to be necessary.

In this sentence, it functions as the predicate:

• Geraham itu perlu mahkota gigi.
• That molar needs a dental crown.

A useful thing to know is that Indonesian often does not need a verb like to be. So you can go straight from the subject to perlu.

Because perlu is a very common and natural way to express need.

Compare:

• Geraham itu perlu mahkota gigi. = natural, concise
• Geraham itu membutuhkan mahkota gigi. = also correct, a bit more explicit/formal

Both are grammatical. Perlu is often simpler and more conversational.

Literally, mahkota gigi means tooth crown:

• mahkota = crown
• gigi = tooth / teeth

Together, in a dental context, it means dental crown.

This is a normal Indonesian noun phrase, where one noun modifies another.

Yes, it could, depending on context.

In dentistry, mahkota gigi can refer to:

• the crown of a tooth anatomically, or
• a dental crown used as treatment

In this sentence, because the tooth needs one, the intended meaning is clearly the dental crown treatment.

Because Indonesian does not have articles like English a, an, and the.

So:

• geraham can mean a molar or the molar
• mahkota gigi can mean a dental crown or the dental crown

Context tells you which English article sounds best in translation.

Yes. In English, a crown is often enough if the dental context is already clear.

But in Indonesian, mahkota by itself usually means a general crown. Adding gigi makes it specifically dental:

• mahkota = crown
• mahkota gigi = dental crown

So mahkota gigi is the clearer and safer expression.

Indonesian often expresses the idea more directly than English.

English might say:

• That molar needs to get a crown
• That molar needs a crown

Indonesian commonly just says:

• Geraham itu perlu mahkota gigi.

That is enough to express the idea. There is no need to add an extra verb unless you want to be more specific.

You would usually add tidak before perlu:

• Geraham itu tidak perlu mahkota gigi.
• That molar does not need a dental crown.

So tidak perlu = does not need / is not necessary.

A common way is to add apakah at the beginning:

• Apakah geraham itu perlu mahkota gigi?
• Does that molar need a dental crown?

In conversation, Indonesians also often just use rising intonation:

• Geraham itu perlu mahkota gigi?

Both are natural, though apakah sounds more explicitly like a question.