sika de sikakensin to rentogen wo ukemasita.

They are doing two different jobs:

• The first 歯科 means the dental department / dental clinic as the place where the action happened.
• The second 歯科 is part of the compound noun 歯科健診, which means dental checkup.

So the structure is basically:

• 歯科で = at the dental clinic
• 歯科健診 = dental checkup

It may look repetitive in English, but in Japanese this is normal.

で marks the place where an action happens.

So:

• 歯科で = at the dental clinic
• 受けました = underwent / had / received

Together, 歯科で tells you where the checkup and X-ray took place.

This is different from に, which often marks a destination, time, or target rather than the location of an action.

と connects nouns and means and.

So:

• 歯科健診とレントゲン = a dental checkup and an X-ray

In this sentence, it gives a straightforward list of the things the speaker had done.

Because 歯科健診とレントゲン works as one combined object.

So the sentence treats dental checkup and X-ray as a single unit:

• [歯科健診とレントゲン] を 受けました

Japanese does this very often. You do not need to put を after each noun in a list like this.

Yes — literally, 受ける often means to receive, but in medical and test-related contexts it commonly means:

• to undergo
• to have
• to take

So here 受けました means something like:

• had a dental checkup and an X-ray
• underwent a dental checkup and an X-ray

This verb is very common with things like:

• 試験を受ける = take an exam
• 診察を受ける = receive a medical examination
• 治療を受ける = receive treatment

Because the speaker is talking about something that already happened.

• 受けました = had / underwent
• 受けます = will have / have in a polite non-past sense

Japanese uses the past form here because the checkup and X-ray were completed.

Yes, レントゲン is very common in everyday Japanese.

It comes from the name Röntgen, the scientist associated with X-rays. In Japanese, レントゲン can refer to:

• an X-ray image
• an X-ray exam
• X-ray photography, depending on context

You may also see:

• X線 = X-rays
• レントゲン撮影 = X-ray imaging

But in casual medical conversation, レントゲン is very natural.

Japanese often leaves out the subject when it is already understood from context.

So even though English usually needs I, Japanese does not have to say:

• 私は歯科で歯科健診とレントゲンを受けました。

The 私は can be omitted if it is obvious who is being talked about. That is extremely common and natural.

It is natural, but the nuance can vary a little.

• 歯科 often means dentistry, dental department, or dental clinic
• 歯医者 often means dentist or dentist’s office in everyday speech

So this sentence is fine, especially in a more formal or medical style. In casual speech, many people might say something like:

• 歯医者で健診とレントゲンを受けました。

That said, 歯科で is completely understandable and natural.

Both can be translated as checkup or medical exam, but there is a small nuance difference:

• 健診 focuses more on a health check
• 検診 often focuses more on screening / examination for problems

In real life, the distinction is not always strict, and both forms appear in medical contexts. For a dental checkup, you may see either:

• 歯科健診
• 歯科検診

Both are common, though the exact choice can depend on the institution or situation.

Those spaces are usually added only for learners.

Normal Japanese writing would be:

歯科で歯科健診とレントゲンを受けました。

Japanese does not normally use spaces between words the way English does. So the spaced version is just a study aid, not standard writing.