Florida study evaluates acidity levels in oral lozenges

May 2, 2018
Researchers at the University of Florida recently tested 11 brands of oral lozenges for harmful acidity levels.

Researchers at the University of Florida recently tested 11 brands of lozenge-type oral moisturizers for harmful acidity levels. The study stated that nine of the 11 tested products are acidic (pH < 7) and could cause tooth erosion.

The two lozenge-type dry mouth remedies that were non-acidic were Nuvora’s Salese and OraCoat’s XyliMelts. The study was conducted by the department of restorative dental sciences at the University of Florida in Gainesville.

The objective of the study was to measure pH levels, titratable acidity, and erosive effect of commercially distributed dry mouth lozenges and adhering discs on teeth, mainly the dentin which is exposed at the gumline. Each product was crushed into five grams of powder and dissolved in 10 mL of water. Acidity was measured with a calibrated pH meter, and titratable acidity was measured by adding sodium hydroxide until the solution reached neutrality. Erosion of tooth structure was measured by placing human teeth in the solution and measuring loss of mass.

The most acidic dry mouth lozenges and adhering discs were reported to be, in order:

  • DenTek OraMoist, pH 2.9
  • Cotton Mouth Lozenges, pH 3.1
  • MedActive Oral Relief Lozenges, pH 3.2
  • Hager Pharma Dry Mouth Drops, pH 4.44
  • Rite Aid Dry Mouth Discs, pH 5.1
  • CVS Dry Mouth Discs, pH 5.3
  • ACT Dry Mouth Lozenges, pH 5.7
  • TheraBreath Dry Mouth Lozenges, pH 5.82

The oral moisturizers that caused the most tooth erosion were, in order:

  • Cotton Mouth Lozenges, 3.1% loss
  • DenTek OraMoist, 2.3% loss
  • MedActive Oral Relief Lozenges, 1.1% loss
  • Rite Aid Dry Mouth Discs, 1.1% loss
  • CVS Dry Mouth Discs, 1.0% loss
  • TheraBreath Dry Mouth Lozenges, 1.0% loss

The study found a high statistical correlation between high acidity and tooth loss. Both remedies that passed the acidity test, Salese and XyliMelts, contain a pH level of 8.0, which is considered not harmful to teeth. Previous studies reported that pH < 6.7 can be erosive to dentin.

The complete study results are available by clicking here.