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Objective: To evaluate the effect of titanium (Ti) particles and ions on oral biofilm growth and composition., Background: Particles and ions of Ti released from dental implants can trigger unfavorable biological responses in human cells. However, their effect on oral biofilms composition has not been tested., Methods: In this blind in situ study, volunteers wore a palatal appliance containing Ti disks for 7 days to allow biofilm formation. Disks were then collected and biofilms were treated, in vitro, with Ti particles (0.75% and 1%), ions (10 and 20 ppm), or a combination of both (1% particles + 20 ppm ions). Biofilms exposed only to medium was used as control group. After 24 hours, biofilms were collected and analyzed by checkerboard DNA-DNA hybridization. Direct effects of Ti particles and ions on biofilm/cellular morphology were evaluated by transmission electron microscopy (TEM)., Results: Ti particles affected biofilm composition, increasing population of four bacterial species (P < .05), while Ti ions showed higher levels of putative pathogens from the orange complex with reduction in species from the yellow complex (P < .05), compared with control. The combination of particles + ions increased green complex and reduced yellow complex proportions (P < .05). TEM showed clusters of particles agglomerated in extracellular environment, while Ti ions were precipitated in both extracellular and intracellular sites., Conclusions: Ti products, especially Ti ions, have the potential to change the microbiological composition of biofilms formed on Ti surfaces. Therefore, the presence of Ti products around dental implants may contribute to microbial dysbiosis and peri-implantitis., (© 2019 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

The starting point for defining effective treatment protocols is a clear understanding of the etiology and pathogenesis of a condition. In periodontal diseases, this understanding has been hindered by a number of factors, such as the difficulty in differentiating primary pathogens from nonpathogens in complex biofilm structures. The introduction of DNA sequencing technologies, including taxonomic and functional analyses, has allowed the oral microbiome to be investigated in much greater breadth and depth. This article aims to compile the results of studies, using next-generation sequencing techniques to evaluate the periodontal microbiome, in an attempt to determine how far the knowledge provided by these studies has brought us in terms of influencing the way we treat periodontitis. The taxonomic data provided, to date, by published association and elimination studies using next-generation sequencing confirm previous knowledge on the role of classic periodontal pathogens in the pathobiology of disease and include new species/genera. Conversely, species and genera already considered as host-compatible and others less explored were associated with periodontal health as their levels were elevated in healthy individuals and increased after therapy. Functional and transcriptomic analyses also demonstrated that periodontal biofilms are taxonomically diverse, functionally congruent, and highly cooperative. Very few interventional studies to date have examined the effects of treatment on the periodontal microbiome, and such studies are heterogeneous in terms of design, sample size, sampling method, treatment provided, and duration of follow-up. Hence, it is still difficult to draw meaningful conclusions from them. Thus, although OMICS knowledge has not yet changed the way we treat patients in daily practice, the information provided by these studies opens new avenues for future research in this field. As new pathogens and beneficial species become identified, future randomized clinical trials could monitor these species/genera more comprehensively. In addition, the metatranscriptomic data, although still embryonic, suggest that the interplay between the host and the oral microbiome may be our best opportunity to implement personalized periodontal treatments. Therapeutic schemes targeting particular bacterial protein products in subjects with specific genetic profiles, for example, may be the futuristic view of enhanced periodontal therapy. [ABSTRACT FROM AUTHOR]

Background: The triclosan-containing dentifrices are effective in controlling biofilm formation and maintaining gingival health; however, there is limited information on their effects during the periodontal maintenance phase. Therefore, the aim of this study was to evaluate the clinical effects of a toothpaste containing 0.3% triclosan on the periodontal parameters of subjects that have been treated for peri-implantitis and were enrolled in a regular maintenance program.Methods: Subjects presenting at least one implant with peri-implantitis and received surgical anti-infective therapy were selected. Sixty days post-surgery (baseline), subjects were randomized into two groups: (1) toothpaste containing 0.3% triclosan + 2.0% PVM/MA copolymer + 1450 ppm fluoride (test) or (2) toothpaste containing 1450 ppm fluoride (control), and were instructed to brush with the assigned toothpaste twice/day for 2 years. They received clinical monitoring at baseline, 3, 6, 12, 18, and 24 months, and professional maintenance every 3 months.Results: Eighty-eight subjects with natural teeth were enrolled in the study (Test, n = 39; Control, n = 49). The test group showed a greater reduction in the percentage of sites exhibiting bleeding on probing (primary outcome) and lower levels of plaque in comparison with the control group after 24 months (P < 0.05). The mean percentage of sites with probing depth ≥5 mm was reduced over the course of the study only in the test group (P < 0.05).Conclusion: A toothpaste containing 0.3% triclosan was more effective than a regular fluoride toothpaste in improving the periodontal clinical condition around natural teeth of periodontally healthy subjects enrolled in a regular maintenance program for 2 years. [ABSTRACT FROM AUTHOR]

Objectives: To test the role of exopolysaccharide (EPS) polymers matrix to modulate the composition/virulence of biofilms growing on titanium (Ti) surfaces, the effect on antibiotic susceptibility, and whether a dual-targeting therapy approach for disrupted EPS matrix could improve the antimicrobial effect. Materials and Methods: A microcosm biofilm model using human saliva as inoculum was used, and the microbial composition was assessed by checkerboard DNA--DNA hybridization. EPS-enriched biofilms virulence was tested using fibroblast monolayer. Povidone-iodine (PI) was used as EPS-targeting agent followed by amoxicillin + metronidazole antibiotic to reduce bacterial biomass using an in situ model. Results: An EPS-enriched environment, obtained by sucrose exposure, promoted bacterial accumulation and led to a dysbiosis on biofilms, favoring the growth of Streptococcus, Fusobacterium, and Campylobacter s pecies a nd e ven s trict a naerobic species related to peri-implant infections, such as Porphyromonas gingivalis and Tannerella forsythia (~3-fold increase). EPS-enriched biofilm transitioned from a commensal aerobic to a pathogenic anaerobic profile. EPS increased biofilm virulence promoting higher host cell damage and reduced antimicrobial susceptibility, but the use of a dual-targeting approach with PI pre-treatment disrupted EPS matrix scaffold, increasing antibiotic effect on in situ biofilms. Conclusion: Altogether, our data provide new insights of how EPS matrix creates an environment that favors putative pathogens growth and shed light to a promising approach that uses matrix disruption as initial step to potentially improve implantrelated infections treatment. [ABSTRACT FROM AUTHOR]

• PEO treatment is a new approach for bioglass-based coating synthesis on Ti surface. • PEO-BG coating enhanced mechanical properties with higher corrosion resistance. • PEO-BG coating is bioactive, biocompatible, and reduces oral biofilm pathogenicity. Although bioactive glass (BG) particle coatings were previously developed by different methods, poor particle adhesion to surfaces and reduced biological effects because of glass crystallization have limited their biomedical applications. To overcome this problem, we have untangled, for the first time, plasma electrolytic oxidation (PEO) as a new pathway for the synthesis of bioactive glass-based coating (PEO-BG) on titanium (Ti) materials. Electrolyte solution with bioactive elements (Na 2 SiO 3 -5H 2 O, C 4 H 6 O 4 Ca, NaNO 3 , and C 3 H 7 Na 2 O 6 P) was used as a precursor source to obtain a 45S5 bioglass- like composition on a Ti surface by PEO. Subsequently, the PEO-BG coating was investigated with respect to its surface, mechanical, tribological, electrochemical, microbiological, and biological properties, compared with those of machined and sandblasted/acid-etched control surfaces. PEO treatment produced a coating with complex surface topography, Ti crystalline phases, superhydrophilic status, chemical composition, and oxide layer similar to that of 45S5-BG (~45.0Si, 24.5 Ca, 24.5Na, 6.0P w/v%). PEO-BG enhanced Ti mechanical and tribological properties with higher corrosion resistance. Furthermore, PEO-BG had a positive influence in polymicrobial biofilms, by reducing pathogenic bacterial associated with biofilm-related infections. PEO-BG also showed higher adsorption of blood plasma proteins without cytotoxic effects on human cells, and thus may be considered a promising biocompatible approach for biomedical implants. [ABSTRACT FROM AUTHOR]

Polymicrobial infection is the main cause of dental implant failure. Although numerous studies have reported the ability of titanium (Ti) surface modifications to inhibit microbial adhesion and biofilm accumulation, the majority of solutions for the utilization of Ti antibacterial surfaces have been testedin in vitro and animal models, with only a few developed surfaces progressing into clinical research. Motivated by this huge gap, we critically reviewed the scientific literature on the existing antibacterial Ti surfaces to help understand these surfaces' impact on the "puzzle" of undesirable dental implant-related infections. This manuscript comprises three main sections: (i) a narrative review on topics related to oral biofilm formation, bacterial-implant surface interactions, and on how implant-surface modifications can influence microbial accumulation; (ii) a critical evidence-based review to summarize pre-clinical and clinical studies in an attempt to "fit pieces into the puzzle" to unveil the best way to reduce microbial loads and control polymicrobial infection around dental implants showed by the current in vivo evidence; and (iii) discussion and recommendations for future research testing emerging antibacterial implant surfaces, connecting basic science and the requirements for future clinical translation. The findings of the present review suggest no consensus regarding the best available Ti surface to reduce bacterial colonization on dental implants. Smart release or on-demand activation surface coatings are a "new piece of the puzzle" , which may be the most effective alternative for reducing microbial colonization on Ti surfaces, and future studies should focus on these technologies. [Display omitted] • The role of titanium surface modifications on bacterial accumulation was critically reviewed. • No consensus was revealed on the best available surface to prevent dental implant contamination. • Pre-clinical and clinical research on clinically relevant oral bacteria is scarce. • Smart release or on-demand activation coatings may provide solutions for the "puzzle" issues. [ABSTRACT FROM AUTHOR]