Quick answer
“My tooth hurts” is У меня́ боли́т зуб — the tooth is the subject. Plural: боля́т зу́бы.
The basics
What is wrong
The treatment
Getting seen
Private is the norm
Most Russians use private dental clinics, which are plentiful, quick to get an appointment at and inexpensive by Western European standards. You will be given a price before treatment — ask Ско́лько бу́дет сто́ить? and expect a straight answer.
Describing the pain
Но́ет — a dull ache. Стреля́ет — shooting pain. Реаги́рует на холо́дное — reacts to cold. Бо́льно куса́ть — it hurts to bite. These four will cover most of what a dentist needs to know.
Typical mistakes
Я боли́т зуб.
У меня́ боли́т зуб.
The tooth is the subject of боли́т.
У меня́ боли́т зу́бы.
У меня́ боля́т зу́бы.
Plural subject, plural verb.
Check yourself
Which is correct?