Bacterial Identification and Monitoring Around Two-Piece Dental Implants by Matrix-Assisted Laser Desorption Ionization Time of Flight Mass Spectrometry (MALDI-TOF MS)

Biofouling on titanium implants: a novel formulation of poloxamer and peroxide for in situ removal of pellicle and multi-species oral biofilm

Eradicating biofouling from implant surfaces is essential in treating peri-implant infections, as it directly addresses the microbial source for infection and inflammation around dental implants. This controlled laboratory study examines the effectiveness of the four commercially available debridement solutions '(EDTA (Prefgel®), NaOCl (Perisolv®), H2O2 (Sigma-Aldrich) and Chlorhexidine (GUM® Paroex®))' in removing the acquired pellicle, preventing pellicle re-formation and removing of a multi-species oral biofilm growing on a titanium implant surface, and compare the results with the effect of a novel formulation of a peroxide-activated 'Poloxamer gel (Nubone® Clean)'. Evaluation of pellicle removal and re-formation was conducted using scanning electron microscope (SEM), energy-dispersive X-ray spectroscopy and X-ray photoelectron spectroscopy to assess the surface morphology, elemental composition and chemical surface composition. Hydrophilicity was assessed through contact angle measurements. The multi-species biofilm model included Streptococcus oralis, Fusobacterium nucleatum and Aggregatibacter actinomycetemcomitans, reflecting the natural oral microbiome's complexity. Biofilm biomass was quantified using safranin staining, biofilm viability was evaluated using confocal laser scanning microscopy, and SEM was used for morphological analyses of the biofilm. Results indicated that while no single agent completely eradicated the biofilm, the 'Poloxamer gel' activated with 'H2O2' exhibited promising results. It minimized re-contamination of the pellicle by significantly lowering the contact angle, indicating enhanced hydrophilicity. This combination also showed a notable reduction in carbon contaminants, suggesting the effective removal of organic residues from the titanium surface, in addition to effectively reducing viable bacterial counts. In conclusion, the 'Poloxamer gel + H2O2' combination emerged as a promising chemical decontamination strategy for peri-implant diseases. It underlines the importance of tailoring treatment methods to the unique microbial challenges in peri-implant diseases and the necessity of combining chemical decontaminating strategies with established mechanical cleaning procedures for optimal management of peri-implant diseases.

Matrix-assisted Laser Desorption Ionization–Time of Flight Mass Spectrometry (MALDI-TOF MS) for subgingival bacteriome identification in a group of treated periodontitis patients: a case series

Periodontitis is a chronic multifactorial polymicrobial infection, characterized by profound modifications of the composition and proportion of the subgingival microbiota. Microbiological laboratory tests are sometimes used in periodontal diagnosis and monitoring of treatment, but both conventional cultivation methods and molecular techniques have some major drawbacks. Therefore, other performant bacterial identification methods must be considered. The aim of the current study was to use Matrix-assisted Laser Desorption Ionization–Time of Flight Mass Spectrometry (MALTI-TOF MS) analysis in association with bacterial culture method to evaluate the modifications of the subgingival bacterial composition in periodontitis patients, before and after cause-related subgingival therapy. Subgingival plaque samples were collected from periodontal pockets before and after subgingival mechanical instrumentation and adjunctive local antimicrobial applications and were cultured in aerobic and anaerobic conditions. Microbial colonies were further assessed using MALDI-TOF-MS. A total of 36 bacterial strains were isolated from a group of 16 patients. All species from the orange complex were identified by MALDI-TOF MS. A marked reduction of detection frequency was observed in most bacterial strains, including the orange complex after cause-related periodontal treatment. The results of this study indicate that MALDI-TOF MS could be considered an accurate method for oral microbial identification and the cause-related periodontal treatment is useful for reducing the microbial burden.