Saya menggunakan flos gigi pada gigi sensitif.

Menggunakan is the more formal, fully inflected verb meaning to use.

• guna = use, useful, function, or the short everyday verb use
• menggunakan = to use in a more standard written style

So:

• Saya menggunakan flos gigi... = more formal / textbook-like
• Saya guna flos gigi... = more casual and very common in speech

Both are understandable and natural, but menggunakan sounds more polished.

Flos gigi means dental floss.

It is made up of:

• flos = floss
• gigi = tooth / teeth

So literally it is something like tooth floss, which matches the English idea dental floss.

This is a borrowed modern term. In everyday Malay, flos gigi is common and easy to understand.

Because the two instances of gigi are doing different jobs:

1. flos gigi
   Here gigi is part of the fixed phrase dental floss

2. pada gigi sensitif
   Here gigi means teeth and refers to the teeth being flossed

So even though the same word appears twice, it is not redundant in Malay.

Here pada means something like on, to, or with regard to.

In this sentence:

• pada gigi sensitif = on sensitive teeth

It marks the thing affected by the action.

A useful comparison:

• pada gigi sensitif = the floss is being used on sensitive teeth
• untuk gigi sensitif = for sensitive teeth, often meaning intended for sensitive teeth

So if you are talking about the action itself, pada makes good sense.

Yes, but the meaning shifts a little.

• menggunakan flos gigi pada gigi sensitif = using dental floss on sensitive teeth
• menggunakan flos gigi untuk gigi sensitif = using dental floss for sensitive teeth, possibly implying it is suitable or intended for them

So:

• pada focuses more on where the action is applied
• untuk focuses more on purpose or suitability

Both can appear in related contexts, but pada fits the literal action more directly.

Because in Malay, adjectives usually come after the noun.

So:

• gigi sensitif = sensitive teeth
• rumah besar = big house
• air panas = hot water

This is one of the most important word-order differences from English.

Not necessarily. Both are possible, but they feel slightly different.

• gigi sensitif = sensitive teeth
• gigi yang sensitif = teeth that are sensitive

The version without yang is shorter and very normal with simple adjective phrases.

The version with yang can sound a bit more explicit or descriptive, especially in longer phrases.

So in this sentence, gigi sensitif is perfectly fine.

It can mean either, depending on context.

Malay nouns often do not change form for singular vs. plural:

• gigi = tooth / teeth

In this sentence, English would naturally translate it as teeth, because people usually floss more than one tooth and because sensitive teeth is the natural phrase in English.

If you really needed to make singular clear, context or extra words would help.

Malay often leaves possession unstated when it is obvious from context, especially with body parts.

So:

• Saya menggunakan flos gigi pada gigi sensitif.
  naturally suggests I use dental floss on sensitive teeth, and listeners may infer they are the speaker’s teeth

If you want to make my explicit, you could say:

• Saya menggunakan flos gigi pada gigi saya yang sensitif.

That is clearer if the context requires it.

By itself, it can mean either, depending on context.

Malay verbs do not change form the way English verbs do for tense.

So Saya menggunakan flos gigi pada gigi sensitif could mean:

• I use dental floss on sensitive teeth
• I am using dental floss on sensitive teeth

If you want to be more specific, Malay usually adds time or aspect words:

• Saya sedang menggunakan... = I am using...
• Saya selalu menggunakan... = I usually use...
• Saya telah menggunakan... = I have used...
• Saya menggunakan... semalam = I used... yesterday

It is grammatical and understandable, but many native speakers might choose a slightly more everyday version.

Possible alternatives:

• Saya guna flos gigi pada gigi sensitif.
  more casual
• Saya menggunakan flos gigi pada gigi saya yang sensitif.
  clearer if you mean my sensitive teeth
• Saya guna flos gigi untuk gigi sensitif.
  more like I use dental floss for sensitive teeth

So the original sentence is fine, but real-life speech often prefers guna over menggunakan, and sometimes adds saya after gigi if possession needs to be clear.