Efficacy of enzymatic mouth rinses for immobilisation of protective enzymes in the in situ pellicle

Aim: Mouth rinses containing enzymes are designed for patients suffering from xerostomia. The objective of the present in situ study was to investigate the efficacy of these rinses for targeted accumulation and immobilisation of protective enzymes in the acquired pellicle. Methods: A number of six healthy subjects carried bovine enamel slabs fixed on individual upper jaw splints for pellicle formation in situ. After 1 min, they rinsed with biotene or BioXtra for 10 min, respectively. Enzyme activities of lysozyme, peroxidase and glucoseoxidase in the in situ pellicle and in the saliva were assayed before as well as 0, 20 and 40 min after the rinses. The assays for the respective enzyme activities were based on fluorogenic substrates. Separate experiments were performed for the different enzymes and mouth rinses, respectively. Statistical evaluation was carried out with the Kruskal-Wallis test. Results: None of the investigated rinses had any significant impact on the activities of lysozyme, peroxidase and glucoseoxidase detectable in the in situ pellicle or in the saliva (Kruskal-Wallis test, p > 0.05). Despite the fact that both products should contain lactoperoxidase activity according to manufacturers' instructions, no peroxidase activity was measurable in the pure mouth rinses. Conclusion: With the tested enzymatic mouth rinses targeted accumulation and immobilisation of protective enzymes in the in situ pellicle did not seem possible. (C) 2009 Elsevier Ltd. All rights reserved.