sikakensin ha asita desu.

A natural everyday reading is:

しかけんしん は あした です。

So the whole sentence is:

しかけんしんはあしたです。

A few notes:

• 歯科健診 = しかけんしん
• は is written ha but pronounced wa when it is a particle
• 明日 is most commonly あした in everyday speech, though あす is also possible in more formal contexts

Because here は is a particle, not part of a regular word.

As a topic particle, は is pronounced wa. This is a standard feature of modern Japanese spelling and pronunciation.

So:

• はな = hana if it is part of a word
• わたしは = watashi wa when は is the topic particle

In 歯科健診は明日です, は marks the topic, so it is read wa.

は marks the topic of the sentence.

So 歯科健診は means something like:

As for the dental checkup, ...

The sentence is setting up 歯科健診 as the thing being talked about, and then the rest of the sentence tells you something about it:

• 歯科健診は = as for the dental checkup
• 明日です = it is tomorrow

A very literal way to feel the structure is:

As for the dental checkup, it is tomorrow.

Because 明日 is a time expression, and in this kind of sentence Japanese often uses it without a particle.

This is very common with words like:

• 今日
• 明日
• 昨日
• 来週
• 去年

So:

• 歯科健診は明日です。 is natural
• 歯科健診は明日にです。 is incorrect

Japanese often allows bare time expressions like this, especially with common words such as tomorrow, today, and yesterday.

です is the polite copula. In simple terms, it is the polite form that corresponds to is / am / are in many beginner-level translations.

Here, です makes the sentence polite and complete:

• 歯科健診は明日です。 = polite
• 歯科健診は明日。 = casual/incomplete-sounding but possible in conversation
• 歯科健診は明日だ。 = casual plain style

In English, we may translate this as The dental checkup is tomorrow, but in Japanese the structure is simply:

[topic] + [time expression] + です

Yes, you can think of that idea as being understood from context.

Japanese often states things more simply than English does. In English, we might naturally say:

• The dental checkup is tomorrow
• The dental checkup takes place tomorrow
• The dental checkup is scheduled for tomorrow

Japanese does not need to spell that out every time. 歯科健診は明日です is enough.

So the sentence is short, but the listener naturally understands the intended meaning from context.

Yes. That is also natural, but the nuance shifts a little.

• 歯科健診は明日です。
  = As for the dental checkup, it is tomorrow.
  Focus feels like when the dental checkup is.

• 明日は歯科健診です。
  = As for tomorrow, it is the dental checkup.
  Focus feels more like what tomorrow is / what is happening tomorrow.

So both are grammatical and natural, but they organize the information differently.

Sometimes, but は is the more neutral choice here.

• 歯科健診は明日です。 = neutral topic statement
• 歯科健診が明日です。 = more focused or contrastive, depending on context

Using が can sound like you are identifying which thing is tomorrow, as if answering a question such as:

Which event is tomorrow?

So for a simple statement, は is usually the better choice.

歯科健診 means a dental checkup or dental examination.

It is a formal compound:

• 歯科 = dentistry / dental
• 健診 = health checkup

So together, it means a dental health check.

This is different from 歯医者, which means dentist or dentist’s office.
So:

• 歯科健診 = the checkup itself
• 歯医者 = the dentist / dental clinic

That is a very good question because both are read けんしん.

In practice:

• 健診 often refers to a routine health checkup
• 検診 often refers more specifically to a screening or examination for possible disease

However, in real life the distinction is not always strict, and organizations may choose one spelling or the other by convention.

So you may also see:

歯科検診

It means essentially the same thing in many everyday contexts.

No. Normally, Japanese is written without spaces.

So the standard written form is:

歯科健診は明日です。

Beginner materials sometimes insert spaces to make the parts easier to see:

歯科健診　は　明日　です。

That is just a learning aid.

Yes, in casual conversation you often can.

Examples:

• 歯科健診は明日。
• 歯科健診、明日だよ。

But for polite, safe Japanese, です is the best choice:

歯科健診は明日です。

So if you are speaking to a teacher, coworker, or someone you do not know well, keep です.