First, you can prepare a mouthwash with ghassoul (clay) and clove oil, which contains eugenol, a substance used by dentists to soothe cavities. There is also an anti-inflammatory plant called "almurra." You can also use toothpaste made with siwak, or grind "oud al-arak" and place it in the cavity.
What the science says: mouth and teeth
What published research says about the remedies mentioned above, for context only — these studies concern material causes, while healing belongs to Allah.
Mouth and teeth
Siwak reduces plaque and gum inflammation (Saudi Med J, 2015) (J Ethnopharmacol, 2022); propolis is studied for oral health (J Funct Biomater, 2024) and honey for mouth sores. Saltwater rinses, clove for dental pain, less sugar: the basics. Precaution: a cavity, an abscess, or a gum that bleeds persistently should be treated by a dentist — natural remedies bring relief in the meantime, they do not repair the damage.