الحشوة في خطة العلاج.

Arabic often leaves out the present-tense to be.

So الحشوة في خطة العلاج literally looks like the filling in the treatment plan, but it means The filling is in the treatment plan.

This is a very common Arabic pattern called a nominal sentence:

• الحشوة = the subject
• في خطة العلاج = the predicate / information about the subject

If you wanted past or future, Arabic would use an actual verb:

• كانت الحشوة في خطة العلاج = The filling was in the treatment plan

It can be understood as a full sentence in Arabic: The filling is in the treatment plan.

Because Arabic allows sentences without a present-tense is, this is complete in context.

That said, without context, it could also appear as a note, heading, or short medical record entry. Arabic often uses short verbless statements in lists and charts.

في usually means in.

Here it introduces the prepositional phrase في خطة العلاج = in the treatment plan.

So the structure is:

• الحشوة = the filling
• في خطة العلاج = in the treatment plan

الـ is the Arabic definite article, equivalent to the.

So:

• حشوة = a filling / filling
• الحشوة = the filling

In this sentence, the noun is definite because it refers to a specific filling.

This is an iḍāfa construction, often called a genitive construction or noun-noun construction.

خطة العلاج literally means:

• plan of the treatment
• more naturally in English: the treatment plan

In an iḍāfa:

• the first noun usually does not take الـ
• the second noun can be definite
• the whole phrase becomes definite because of the second noun

So:

• خطة علاج = a treatment plan / plan of treatment
• خطة العلاج = the treatment plan / plan of the treatment

Because it is the second part of the iḍāfa: خطة العلاج.

The second noun in an iḍāfa often carries the definiteness. Since العلاج is definite, the whole phrase خطة العلاج is definite.

So even though خطة does not have الـ, the full phrase still means the treatment plan.

Yes, الحشوة is grammatically feminine.

A major clue is the ending ة called tāʾ marbūṭa. Many Arabic nouns ending in ة are feminine.

So الحشوة is treated as a feminine noun in grammar. If you referred back to it with an adjective or pronoun, those would usually be feminine too.

In normal pause, الحشوة is pronounced roughly al-ḥashwa.

The final ة usually sounds like -a when you stop on the word.

In full formal pronunciation with case endings, it would be الحشوةُ = al-ḥashwatu, because it is the subject of the sentence.

So you may see or hear:

• pausal form: al-ḥashwa
• fully inflected formal form: al-ḥashwatu

In fully vocalized formal Arabic, it would be:

الحَشْوَةُ في خُطَّةِ العِلاجِ

Why?

• الحشوةُ is the subject, so it is nominative
• في makes the following noun genitive
• خطةِ is after في, so it is genitive
• العلاجِ is the second part of the iḍāfa, so it is also genitive

In everyday writing, these endings are usually not written.

Not always. حشوة can mean filling, stuffing, or something that fills another thing, depending on context.

But with خطة العلاج, the medical or dental context strongly suggests filling in the dental sense.

So context is what narrows the meaning here.

Yes, Arabic word order is flexible, but the original order is the most neutral here:

الحشوة في خطة العلاج

This presents:

1. the topic: الحشوة
2. the information about it: في خطة العلاج

You could front the prepositional phrase for emphasis in some contexts, but the given version is the most straightforward for a learner.