Pellicle (dental), the thin layer of salivary glycoproteins deposited on the teeth of many species through normal biologic processes

Activity and distribution pattern of enzymes in the in-situ pellicle of children Publication date: August 2019 Source: Archives of Oral Biology, Volume 104 Author(s): Susann Hertel, Annika Schulz, Roman Lang, Thomas Hofmann, Belinda König, Matthias Hannig, Christian Hannig Abstract Objective This study investigated, for the first time, pellicle enzymes with respect to their activity, distribution and fluorescence pattern in children with different caries experience. Design In-situ pellicles were collected from 41 children (aged 4–6 years) with different caries status; 17 of them were caries-free (dmf = 0), 12 had dental restorations but no current caries (dmf ≥ 2) and 12 had at least two carious lesions (dmf ≥ 2). Bovine enamel samples were fixed on individual upper jaw braces for pellicle formation. After 30 min of intraoral exposure, the pellicle and saliva samples were analysed for the activities of amylase, lysozyme, peroxidase and glucosyltransferase (GTF). The distribution of these enzymes, including GTF-isoforms B, C and D, and the pellicle ultrastructure were examined by gold-immunolabelling and transmission electron microscopy (TEM). Furthermore, interactions between pellicle enzymes and adherent bacteria were visualised using combined fluorescence and immunofluorescence labelling. Results There were no significant differences in the pellicle enzyme activities between the study groups. TEM analysis revealed the absence of GTF C and D in the pellicle of caries-active children. Amylase, peroxidase and GTF-isoforms showed a random distribution within the pellicle layer; lysozyme was found in the form of clusters. A similar ultrastructural pattern was observed for all subjects. Fluorescence labelling technique enabled visualisation of all enzymes, except for GTF B. Conclusion Pellicle enzyme activities and ultrastructure are not associated with children’s caries status. Further investigation is needed to assess the influence of individual GTF-isoforms on caries susceptibility in children.