haisya ha te wo syoudokusimasu.

• 歯医者 is read はいしゃ
• 消毒します is read しょうどくします

A few pronunciation notes:

• In はいしゃ, the しゃ is one sound: sha
• 消毒 is a Sino-Japanese word, so it has an on-yomi reading: しょうどく
• します is the polite form of する, meaning to do

So the full sentence is read:

はいしゃ は て を しょうどくします。

Here, 歯医者 most naturally means dentist.

That word can sometimes refer to:

• the dentist (the person), or
• the dentist’s office / dental clinic

But in this sentence, because it is followed by は and then does an action, it is understood as the dentist:

歯医者は = As for the dentist, ...

A place would not normally disinfect hands in this way, so the person reading is the natural one.

は marks the topic of the sentence.

So:

• 歯医者は = As for the dentist, ...

This does not always mean strong contrast, but it sets up what the sentence is about.

In this sentence:

• 歯医者 is the topic
• 手 is the object
• 消毒します is the action

A natural grammatical breakdown is:

• 歯医者 は = as for the dentist
• 手 を = hands
• 消毒します = disinfects / sanitizes

を marks the direct object of the verb—the thing being acted on.

Here:

• 手を消毒します = disinfects hands

So 手 is what gets disinfected.

This is very standard Japanese sentence structure:

topic + object + verb

So:

• 歯医者は = the dentist
• 手を = hands
• 消毒します = disinfects

Japanese often leaves out possessive words like my, your, his, or their when the meaning is obvious from context.

So 手を消毒します often naturally means:

• disinfects his hands
• disinfects her hands
• disinfects their hands

depending on who the topic is.

Because the topic is 歯医者, the most natural interpretation is:

The dentist disinfects their hands.

This is especially common with body parts in Japanese. For example:

• 手を洗います = wash one’s hands
• 顔を洗います = wash one’s face

Japanese usually does not need 自分の手 or 彼の手 unless there is a special reason to be explicit.

It can mean either hand or hands. Japanese nouns usually do not show singular vs. plural the way English does.

So 手 can be:

• a hand
• hands

In this sentence, English would usually translate it as hands, because that is what makes the most sense:

The dentist disinfects their hands.

Japanese relies on context rather than changing the noun form.

消毒します means disinfects, sanitizes, or sterilizes depending on context.

The base word is:

• 消毒 = disinfection / sterilization / sanitization

Then:

• 消毒する = to disinfect
• 消毒します = polite form of to disinfect

In a sentence about a dentist and hands, sanitizes or disinfects is the most natural English idea.

So this sentence suggests something like:

• the dentist sanitizes their hands
• the dentist disinfects their hands before treatment

Because Japanese normally puts the verb at the end of the clause.

A very common Japanese pattern is:

topic / subject + object + verb

So:

• 歯医者は = the dentist
• 手を = hands
• 消毒します = disinfects

This is different from English, which usually uses:

subject + verb + object

English:

• The dentist disinfects hands.

Japanese:

• Dentist + hands + disinfects

That final verb position is one of the most basic features of Japanese grammar.

It is non-past, which in Japanese can cover both:

• present / habitual
• future

So depending on context, it could mean:

• The dentist disinfects their hands.
• The dentist will disinfect their hands.

Without additional context, English often translates it as a simple present statement:

• The dentist disinfects their hands.

Japanese does not force the same present/future distinction here that English often does.

The verb ends in -ます, which makes it polite:

• 消毒する = plain form
• 消毒します = polite form

This is the standard polite style used in:

• textbooks
• neutral conversation
• formal situations
• descriptions and explanations

So the sentence is in polite Japanese, which is very common for beginner example sentences.

Yes, grammatically it could, because Japanese does not explicitly state whose hands they are.

However, the most natural interpretation is that the dentist disinfects their own hands, because:

• there is no other person mentioned
• body-part possession is often omitted in Japanese
• disinfecting one’s own hands is a normal action for a dentist

If the sentence specifically meant a patient’s hands, Japanese would often make that clearer, for example by mentioning the patient.

So:

• possible grammatically: yes
• most likely in context: the dentist disinfects their own hands

No. Normal Japanese writing usually does not use spaces between words.

So this sentence would normally be written as:

歯医者は手を消毒します。

The spaces are probably there just to help learners see the parts more easily:

• 歯医者
• は
• 手
• を
• 消毒します

That is common in beginner materials, but it is not standard everyday Japanese writing.