A Biofilm Pocket Model to Evaluate Different Non-Surgical Periodontal Treatment Modalities in Terms of Biofilm Removal and Reformation, Surface Alterations and Attachment of Periodontal Ligament Fibroblasts

• Published in: PloS one 2015-06, Vol.10 (6), p.e0131056-e0131056
• Main Authors: Hägi, Tobias T, Klemensberger, Sabrina, Bereiter, Riccarda, Nietzsche, Sandor, Cosgarea, Raluca, Flury, Simon, Lussi, Adrian, Sculean, Anton, Eick, Sigrun
• Format: Article
• Language: English
• Subjects: Alterations; Analysis; Antimicrobial agents; Attachment; Bacteria; Bacteria - growth & development; Biofilms; Cell Adhesion; Chlorhexidine; Colony Count, Microbial; Computer simulation; Cyclohexane; Dentin; Dentin - pathology; Dentistry; Disease; Erythritol; Fibroblasts; Fibroblasts - pathology; Humans; Instrumentation; Instruments; Lasers; Life assessment; Ligaments; Lysergide; Medicine; Microorganisms; Models, Biological; Pediatrics; Periodontal ligament; Periodontal Ligament - microbiology; Periodontal Ligament - pathology; Periodontal Ligament - surgery; Periodontal Pocket - microbiology; Periodontal Pocket - pathology; Periodontal Pocket - surgery; Polishing; Prevention; Recolonization; Reduction; Surface Properties; Surface roughness; Surgery; Teeth; Therapeutics; Tooth - pathology; Variance analysis
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0131056

There is a lack of suitable in vitro models to evaluate various treatment modalities intending to remove subgingival bacterial biofilm. Consequently, the aims of this in vitro-study were: a) to establish a pocket model enabling mechanical removal of biofilm and b) to evaluate repeated non-surgical periodontal treatment with respect to biofilm removal and reformation, surface alterations, tooth hard-substance-loss, and attachment of periodontal ligament (PDL) fibroblasts. Standardized human dentin specimens were colonized by multi-species biofilms for 3.5 days and subsequently placed into artificially created pockets. Non-surgical periodontal treatment was performed as follows: a) hand-instrumentation with curettes (CUR), b) ultrasonication (US), c) subgingival air-polishing using erythritol (EAP) and d) subgingival air-polishing using erythritol combined with chlorhexidine digluconate (EAP-CHX). The reduction and recolonization of bacterial counts, surface roughness (Ra and Rz), the caused tooth substance-loss (thickness) as well as the attachment of PDL fibroblasts were evaluated and statistically analyzed by means of ANOVA with Post-Hoc LSD. After 5 treatments, bacterial reduction in biofilms was highest when applying EAP-CHX (4 log10). The lowest reduction was found after CUR (2 log10). Additionally, substance-loss was the highest when using CUR (128±40 µm) in comparison with US (14±12 µm), EAP (6±7 µm) and EAP-CHX (11±10) µm). Surface was roughened when using CUR and US. Surfaces exposed to US and to EAP attracted the highest numbers of PDL fibroblasts. The established biofilm model simulating a periodontal pocket combined with interchangeable placements of test specimens with multi-species biofilms enables the evaluation of different non-surgical treatment modalities on biofilm removal and surface alterations. Compared to hand instrumentation the application of ultrasonication and of air-polishing with erythritol prevents from substance-loss and results in a smooth surface with nearly no residual biofilm that promotes the reattachment of PDL fibroblasts.