Dental plaque is a biofilm in which bacteria (streptococci and other species), food debris, and saliva components form a sticky layer on the enamel. If not removed for 1–3 days, the plaque mineralizes with calcium salts from saliva and turns into tartar (calculus), which provokes caries and gingivitis. At home, only soft plaque can be removed — with a toothbrush, floss, and water flosser; hard tartar is removed by a dentist using AirFlow or ultrasound. In Spain, a basic professional cleaning (limpieza dental / profilaxis) costs approximately 40–80 €, while deeper treatment of gum pockets (curetaje) costs 60–250 € depending on the number of zones. It is recommended to have a cleaning every 6–12 months; at the AP-Denta clinic in Torrevieja, this can be done in one visit.

Aphthous stomatitis is an inflammatory lesion of the oral mucosa in which painful ulcers (aphthae) 2–10 mm in diameter, with a white coating and a red border, appear on the inside of the cheeks, tongue, or palate. According to observations by pediatric dentists at the AP-Denta clinic in Torrevieja, aphthae most commonly occur in children aged 1 to 6 years and, with proper care, resolve on their own within 7–14 days.