Если воспаление уже прошло, врач поставит новую пломбу без боли.

Если means if and introduces a conditional clause. In Russian, when an если-clause comes first, it is normally separated from the main clause by a comma:

• Если воспаление уже прошло, = If the inflammation has already gone away,
• врач поставит новую пломбу без боли. = the doctor will put in a new filling without pain.

If you reverse the order, the comma usually remains:

• Врач поставит новую пломбу без боли, если воспаление уже прошло.

The subject is воспаление (inflammation), which is a neuter noun in Russian. Past tense verbs agree in gender/number with their subject, so:

• воспаление (neuter singular) → прошло (neuter singular past)

Compare:

• боль прошла (the pain went away; боль is feminine)
• симптомы прошли (the symptoms went away; plural)

уже means already. уже прошло emphasizes that the inflammation has ended by the relevant time (before the doctor does the filling). It often implies “good, it’s over now” or “it has finally passed.”

Without уже, Если воспаление прошло... is still “If the inflammation has gone away...”, but less explicit about already.

прошло is from the perfective verb пройти and focuses on the result: the inflammation is over. That fits the condition for the next action.

проходило (imperfective past) would mean “was going away/was passing” (process/background), not “has ended,” and would sound wrong for “if it’s already finished.”

Russian typically uses the future to describe what will happen if the condition is met:

• врач поставит = “the doctor will place/put (in)”

Using present tense isn’t standard here. Russian doesn’t usually do the English “If it’s fine, the doctor puts in...” for future meaning in this kind of one-time situation.

поставить literally means to put/place/set, but it’s a very common verb for medical/dental procedures:

• поставить пломбу = “to put in a filling”
• поставить диагноз = “to make/give a diagnosis”

сделает пломбу would sound like “make a filling (as an object),” and установит пломбу is possible but more formal/technical; поставит is the natural everyday choice.

Because пломба is the direct object of the verb поставит (“will put in what?”). For a feminine noun like пломба, accusative singular typically ends in -у:

• nominative: пломба
• accusative: пломбу

So: врач поставит (что?) пломбу.

новую means new and agrees with пломбу (feminine accusative singular). Adjectives match the noun in gender/number/case:

• новая пломба (nom. fem. sg.)
• новую пломбу (acc. fem. sg.)

It literally means without pain and functions like “painlessly / with no pain” in English.

After без (“without”), Russian uses the genitive case, so:

• nominative: боль
• genitive: боли

So: без (чего?) боли.

Both can work:

• без боли = “without pain” (neutral, conversational)
• безболезненно = “painlessly” (more adverb-like and slightly more “clinical”)

The sentence with без боли sounds very natural and reassuring in everyday speech.

Russian often doesn’t need then because the conditional structure already implies the sequence. You can add то for emphasis:

• Если воспаление уже прошло, то врач поставит новую пломбу без боли.

The то is optional and adds a bit of “in that case / then.”

Usually there’s a small pause after the если-clause (matching the comma). Intonation rises slightly through the condition and then resolves in the main clause:

• Если воспаление уже прошло, | врач поставит новую пломбу без боли. This mirrors English “If …, the doctor will …” but Russian relies more on that pause and the comma.