In vitro evaluation of a novel biofilm remover.

Objective: To evaluate a novel device for its efficacy in removing experimental biofilm from root surfaces and its potential for concomitantly removing/roughening the surface substance.

Methods And Materials: A novel acrylic rotary device (biofilm remover, BR) was tested in vitro in three experiments: surface loss, surface roughness [positive controls: Perioset (PS) and Proxoshape (PR)] and biofilm removal [positive controls: ultrasonic (US) and PS]. Surface loss/surface roughness was evaluated for dentin samples instrumented for three 20 s periods.

Mechanical and hydrodynamic homecare devices to clean rough implant surfaces - an in vitro polyspecies biofilm study.

Objectives: To investigate the cleaning efficacy of a mechanical and a hydrodynamic homecare device on biofilm-coated titanium surfaces with and without chlorhexidine.

Material And Methods: Six-species biofilms were grown on 108 SLA-titanium discs, which were cleaned as follows: sonic toothbrush alone (i) or in combination with either a 0.2% chlorhexidine (ii) or a placebo gel (iii) and oral irrigator (hydrodynamic action) with water (iv) or combined with 0.

Polyspecies biofilm formation on implant surfaces with different surface characteristics.

Objective: To investigate the microbial adherence and colonization of a polyspecies biofilm on 7 differently processed titanium surfaces.

Material And Methods: Six-species biofilms were formed anaerobically on 5-mm-diameter sterilized, saliva-preconditioned titanium discs. Material surfaces used were either machined, stained, acid-etched or sandblasted/acid-etched (SLA).

Down-regulation of NLRP3 inflammasome in gingival fibroblasts by subgingival biofilms: involvement of Porphyromonas gingivalis.

Recognition of pathogen-associated molecular patterns that activate IL-1β is regulated by inflammasomes, predominantly of the nucleotide-binding oligomerization domain-like receptor (NLR) family. NLRP3 inflammasome is involved in the innate immune responses in periodontal disease. This is an inflammatory condition that destroys the tooth-supporting (periodontal) tissues, initiated by the subgingival formation of multi-species biofilms, frequently including the Gram-negative species Porphyromonas gingivalis.

Induction of prostaglandin E(2) and interleukin-6 in gingival fibroblasts by oral biofilms.

Polymicrobial oral biofilms attaching on tooth surfaces can trigger inflammatory responses by the neighbouring tooth-supporting periodontal tissues. An excessive inflammatory response can cause destruction of the periodontal tissues, including the alveolar bone, thus resulting in periodontitis. Mediators of inflammation, such as prostaglandin E(2) (PGE(2) ) and interleukin-6, are primary regulators of alveolar bone destruction in periodontitis.

Validation of the Zürich burn-biofilm model.

Background: Despite advances in the use of topical and parenteral antimicrobial therapy and the practice of early tangential burn-wound excision, bacterial infection remains a major problem in the management of burn victims today. The purpose of this study was to design and evaluate a polyspecies biofilm model with bacteria known to cause severe infections in burn patients. The model is simple to prepare, maintain and analyse, and allows for short-term exposure to antimicrobials.

In vitro effect of chlorhexidine mouth rinses on polyspecies biofilms.

The aim of this study was to use the Zurich polyspecies biofilm model to compare the antimicrobial effects of chlorhexidine mouth rinses available on the Swiss market. As positive and negative controls, aqueous 0.15% CHX solution and water were used, respectively.

Regulation of NLRP3 and AIM2 inflammasome gene expression levels in gingival fibroblasts by oral biofilms.

Periodontal disease is an inflammatory condition that destroys the tooth-supporting tissues. The inflammation is initiated by oral bacteria in the form of multi-species biofilms, and is dominated by cytokines of the IL-1 family. IL-1 activation and processing is regulated by Caspase-1, within intracellular protein complexes, known as "inflammasomes".

The RANKL-OPG system is differentially regulated by supragingival and subgingival biofilm supernatants.

Periodontitis is an inflammatory condition that destroys the tooth supporting tissues, including the alveolar bone. It is triggered by polymicrobial biofilms attaching on tooth surfaces, which can be supragingival or subgingival. Bone resorption is triggered by receptor activator of NF-κB ligand (RANKL) and blocked by its soluble decoy receptor osteoprotegerin (OPG), which are cytokines of the tumor necrosis factor ligand and receptor families, respectively.

Dental caries in rats associated with Candida albicans.

In addition to occasional opportunistic colonization of the oral mucosa, Candida albicans is frequently found in carious dentin. The yeast's potential to induce dental caries as a consequence of its pronounced ability to produce and tolerate acids was investigated. Eighty caries-active Osborne-Mendel rats were raised on an ampicillin-supplemented diet and exposed to C.

Phylogenetic group- and species-specific oligonucleotide probes for single-cell detection of lactic acid bacteria in oral biofilms.

Background: The purpose of this study was to design and evaluate fluorescent in situ hybridization (FISH) probes for the single-cell detection and enumeration of lactic acid bacteria, in particular organisms belonging to the major phylogenetic groups and species of oral lactobacilli and to Abiotrophia/Granulicatella.

Results: As lactobacilli are known for notorious resistance to probe penetration, probe-specific assay protocols were experimentally developed to provide maximum cell wall permeability, probe accessibility, hybridization stringency, and fluorescence intensity. The new assays were then applied in a pilot study to three biofilm samples harvested from variably demineralized bovine enamel discs that had been carried in situ for 10 days by different volunteers.

Biofilm reduction and staining potential of a 0.05% chlorhexidine rinse containing essential oils.

Objectives: To assess the biofilm reduction and discolouration potential of a new 0.05% chlorhexidine (CHX) digluconate solution, containing additional essential oil and alcohol components, compared with that of standard control CHX solutions (0.05% and 0.

Effects of xylitol on survival of mutans streptococci in mixed-six-species in vitro biofilms modelling supragingival plaque.

Xylitol has been claimed to reduce mutans streptococci (MS) in dental plaque by energy-consuming futile metabolic cycles. This study aimed to investigate the effects of xylitol on MS in an in vitro 6-species oral biofilm model. Each multispecies biofilm contained either a laboratory reference strain, a fresh isolate, a xylitol-sensitive or a xylitol-resistant strain of Streptococcus mutans or Streptococcus sobrinus.

Oral biofilm challenge regulates the RANKL-OPG system in periodontal ligament and dental pulp cells.

Inflammatory bone destruction triggered by oral bacteria is a hallmark of chronic and apical periodontitis. Receptor activator of NF-κB ligand (RANKL) activates bone resorption, whereas osteoprotegerin (OPG) blocks its action. These are members of the tumor necrosis factor ligand and receptor families, respectively.

Potential of shock waves to remove calculus and biofilm.

Effective calculus and biofilm removal is essential to treat periodontitis. Sonic and ultrasonic technologies are used in several scaler applications. This was the first feasibility study to assess the potential of a shock wave device to remove calculus and biofilms and to kill bacteria.

In vitro modeling of host-parasite interactions: the 'subgingival' biofilm challenge of primary human epithelial cells.

Background: Microbial biofilms are known to cause an increasing number of chronic inflammatory and infectious conditions. A classical example is chronic periodontal disease, a condition initiated by the subgingival dental plaque biofilm on gingival epithelial tissues. We describe here a new model that permits the examination of interactions between the bacterial biofilm and host cells in general.

Multi-species biofilm formation on dental materials and an adhesive patch.

Purpose: This laboratory study assessed the influence of surface roughness and contact time on the formation of a multi-species biofilm on dental materials (adhesive patch, composite, amalgam and enamel).

Materials And Methods: Rough and smooth specimens of each material were prepared and the mean surface roughness was assessed profilometrically. The biofilms were then allowed to grow either for 15 min or 15 h respectively on saliva-preconditioned specimens of each material, and colony-forming units on blood agar were counted (N = 9/group) Surface morphology was assessed using a scanning electron microscope.

The mysterious appearance of enterococci in filled root canals.

In this narrative review, the potential reasons for the high occurrence of enterococci in filled root canals are explored. The pulpless root canal appears to be a habitat for these bacteria, particularly for Enterococcus faecalis. However, re-surveying the literature in caries research, it can be concluded that, contrary to earlier belief, enterococci are rare if ever found at the advancing front of dentinal lesions.

Cariogenicity of soluble starch in oral in vitro biofilm and experimental rat caries studies: a comparison.

Aims: Common belief suggests that starch is less cariogenic than sugar; however, the related literature is quite controversial. We aimed to compare cariogenic and microbiological effects of soluble starch in both a standard animal model and an oral biofilm system, and to assess the possible substitution of the animal model.

Methods And Results: Six-species biofilms were grown anaerobically on enamel discs in saliva and medium with glucose/sucrose, starch (average molecular weight of 5000, average polymerization grade of 31), or mixtures thereof.

Effect of chlorhexidine/thymol and fluoride varnishes on dental biofilm formation in vitro.

This study evaluated the effect of chlorhexidine/thymol (CHX/T) and fluoride (F) varnishes on biofilm formation in vitro. Hydroxyapatite discs coated with varnish were first immersed in saline for 0, 3, 7 or 14 d, then immersed in pasteurized saliva. The discs were incubated for 20 h with a bacterial suspension containing Actinomyces naeslundii, Fusobacterium nucleatum, Streptococcus oralis, and Veillonella dispar.

A novel TEM contrasting technique for extracellular polysaccharides in in vitro biofilms.

In the past, the visualization of the extracellular matrix of biofilms on an ultrastructural level was hampered by shrinkage artifacts. In addition, the reproducible contrasting of extracellular polysaccharides (EPS) has not satisfactorily been solved. Here we describe a method overcoming these difficulties, which produces artifact-free transmission electron microscopic (TEM) images using multispecies biofilms grown in vitro.

Efficacy of gasiform ozone and photodynamic therapy on a multispecies oral biofilm in vitro.

Ozone gas and photodynamic therapy (PDT) have been claimed to be antimicrobially effective. This study assessed their antimicrobial potential in vitro. Mature six-species oral biofilms were treated as follows (n = 9 per group): (i) a 60-s application of gasiform vacuum-ozone or vacuum alone (on wet or air-dried biofilm samples); (ii) PDT (i.

In vitro quantitative light-induced fluorescence to measure changes in enamel mineralization.

A sensitive, quantitative method for investigating changes in enamel mineralization of specimens subjected to in vitro or in situ experimentation is presented. The fluorescence-detecting instrument integrates a Xenon arc light source and an object positioning stage, which makes it particularly suitable for the nondestructive assessment of demineralized or remineralized enamel. We demonstrate the ability of in vitro quantitative light-induced fluorescence (QLF) to quantify changes in mineralization of bovine enamel discs that had been exposed in vitro to a demineralizing gel (n=36) or biofilm-mediated demineralization challenges (n=10), or were carried in situ by three volunteers during a 10-day experiment (n=12).

Effects of Streptococcus mutans gtfC deficiency on mixed oral biofilms in vitro.

The aim of this study was to examine the influence of glucosyltransferase-gene-negative (gtf-) Streptococcus mutans strains unable to synthesize water-insoluble or soluble glucan on the structure and macromolecular diffusion properties of in vitro grown mixed oral biofilms. Biofilms modeling supragingival plaque consisted of Actinomyces naeslundii OMZ 745, Candida albicans OMZ 110, Fusobacterium nucleatum KP-F2, Streptococcus oralis SK 248, Veillonella dispar ATCC 17748T and one of the S. mutans strains UA159, OMZ 966, OMZ 937 or OMZ 977.

A comprehensive system for washing, pre-disinfecting and sterilizing of dental and surgical instruments.

Purpose: The purpose of this study was to test and describe in detail a newly developed comprehensive system for washing, pre-disinfecting and sterilizing of dental and surgical instruments.

Materials And Methods: The system consists of a combined washing and steam-operated pre-disinfection apparatus and newly developed trays, in which assorted instruments can be washed and disinfected without handling individual instruments. The system was subjected to a large number of tests.