Reactions in the oral mucous membrane after exposure to CarisolvTM ‐ combined results from a clinical screening test in humans and an experimental study in rats

Objective: To evaluate reactions in the oral mucosa after direct contact with Carisolv^TM Setting: The Faculty of Odontology in Göteborg, Sweden. Subjects: 34 healthy persons for a clinical screening test and 35 Sprague Dawley rats for a histological study. Desing: Mixed Carisolv^TM or 0.5 % NaOCl were soaked in paper and applied to either side of the medial frenula of the lower lip of 34 persons. The solutions were left on the oral mucosa for three minutes. Inspection was made and photographs were taken immediately after exposure and also after 1 hour, 24 hours, and 72 hours. Mixed Carisolv^TM was applied in a similar manner as described above to 35 adult Sprague Dawley rats. The animals were killed and biopsies were taken immediately after Carisolv^TM exposure and also after 1 hour, 24 hours, and 48 hours. The biopsies were sectioned and prepared for histomorphometrical evaluation in light microscopy where cells were counted on regions from the epithelium layer deeper into the mucous membrane. Results: Some adverse reactions were detected on the oral mucosa of humans up to 24 hours after Carisolv^TM exposure for 3 minutes. The detected inflammatory reactions were slight and no patient felt any discomfort. The results of the histological study on rat did not show any statistically significant increase of the number of cells at any time after Carisolv^TM exposure. Conclusions: If the oral mucosa gets in direct contact with Carisolv^TM for 3 minutes no or only a weak inflammatory response may be expected.