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

Abstract

Background and AimThere 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.Material and MethodsStandardized 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.ResultsAfter 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.ConclusionThe 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.

Influence of different instrumentation modalities on the surface characteristics and biofilm formation on dental implant neck, in vitro

“…() and Hägi et al. (), and were often observed in our SEM photographs. It should be kept in mind that the present study did not use sodium bicarbonate, which has been shown in many other studies to be more abrasive on tooth and titanium implant surfaces (Jost‐Brinkmann ; Petersilka et al.…”

“…; Hägi et al. ), and prevent bacterial adhesion due to the surface changes created or deposits left on the surface (Duarte et al. ).…”

Deep sequencing of biofilm microbiomes on dental composite materials

“…Nevertheless, our model has advantages over those in current use due to its intrinsic complexity. In contrast, most current models are based on a single species (usually S. mutans, Porphyromonas gingivalis or Aggregatibacter actinomycetemcomitans) or communities of up to 12 species, allowing the investigation of primary or secondary caries [32][33][34] or the efficiency of antimicrobials and disinfectants [35][36][37].…”

Osteoblast growth, after cleaning of biofilm‐covered titanium discs with air‐polishing and cold plasma

“…An unpublished small-scale trial in our laboratory corroborates a decreased contact angle after rinsing with CHX solution (0.2% in aqua distillate) compared to a pure water drop (aqua distillate) on hydrophobic titanium disc. The ion of CHX salt (digluconate) used in powder (Hägi et al, 2015) may bind onto the titanium surface (Barbour, O'Sullivan, & Jagger, 2007). This unexpected hydrophilic surface may support cell attachment (Lang et al, 2011).…”