One-year bacterial colonization patterns of Staphylococcus aureus and other bacteria at implants and adjacent teeth

Microbiological and Imaging-Based Evaluations of Photodynamic Therapy Combined with Er:YAG Laser Therapy in the In Vitro Decontamination of Titanium and Zirconia Surfaces

The oral cavity's soft and hard tissues create a conducive environment for microbial proliferation and biofilm development, facilitating the colonization of prosthodontic and implant materials such as titanium (Ti) and zirconia (Zr). This study aimed to compare the efficacy of conventional decontamination methodologies (i.e., chemical and mechanical, using 0.12% digluconate chlorhexidine (CHX) solution-treatment and airflow) to adjunctive laser-based interventions on Ti and Zr substrates inoculated with Staphylococcus (S.) aureus ATCC 25923. Additionally, this investigation sought to elucidate the impact of these treatments on temperature variations and surface integrity, analyzing the laser irradiation effects on these prevalent dental materials. Experimental configurations were delineated for both Ti and Zr samples across four groups: (1) a conventional treatment group (CV); (2) a photodynamic therapy group (PDT); (3) an Er:YAG laser treatment group (Er); (4) a combined PDT and Er:YAG treatment group (PDTEr). Also, a negative control group (C) that received no treatment was considered. The decontamination of the inoculated disc samples was evaluated by quantifying the microbial colonies in colony-forming units per milliliter (CFU/mL). Temperature variations on the surface of the samples were determined during laser treatments. Surface modifications were investigated using scanning electron microscopy (SEM) and optical coherence tomography (OCT). For statistical analysis, Fisher 95% confidence intervals, Hsu's MCB method, and the Kruskal-Wallis test were applied. With regard to the 105 CFU/mL of the negative control group, results indicated average values equal for each study group to (1) 2.66 CFU/mL for Ti and 2 CFU/mL for Zr for the CV group; (2) 0.33 CFU/mL for Ti and 1 CFU/mL for Zr for the PDT group; (3) 1.25 CFU/mL for Ti and 0 CFU/mL for Zr for the Er group; (4), and 0 CFU/mL for both Ti and Zr for the PDTEr group. Therefore, the combined PDT and Er:YAG treatment (PDTEr) and the singular PDT modality outperformed conventional decontamination methods in eradicating S. aureus biofilms from both Ti and Zr surfaces. Notably, the PDTEr regime achieved a comprehensive elimination of microbial colonies on treated substrates. Surface examination employing OCT demonstrated discernible alterations in the surface morphology of samples subjected to Er:YAG and combined PDT and Er:YAG treatments. Temperature checks during treatments showed no major changes, suggesting the applied laser methods are safe. In conclusion, PDTEr and PDT eliminated bacteria more effectively, but Zr surfaces were more resilient, making them better for microbe-controlling applications. Also, the study demonstrated that the (less costly but lower resolution) OCT method can replace SEM for such investigations.

Bioactivity and antibacterial effects of zinc-containing bioactive glass on the surface of zirconia abutments

OBJECTIVES

This study aimed to enhance gingival fibroblast function and to achieve antibacterial activity around the implant abutment by using a zinc (Zn)-containing bioactive glass (BG) coating.

METHODS

45S5 BG containing 0, 5, and 10 wt.% Zn were coated on zirconia disks. The release of silica and Zn ions in physiological saline and their antibacterial effects were measured. The effects of BG coatings on human gingival fibroblasts (hGFs) were assessed using cytotoxicity assays and by analyzing the gene expression of various genes related to antioxidant enzymes, wound healing, and fibrosis.

RESULTS

BG coatings are capable of continuous degradation and simultaneous ion release. The antibacterial effect of BG coatings increased with the addition of Zn, while the cytotoxicity remained unchanged compared to the group without coatings. BG coating enhances the expression of angiogenesis genes, while the Zn-containing BG enhances the expression of antioxidant genes at an early time point. BG coating enhances the expression of collagen genes at later time points.

CONCLUSIONS

The antibacterial effect of BG improved with the increase in Zn concentration, without inducing cytotoxicity. BG coating enhances the expression of angiogenesis genes, and Zn-containing BG enhances the expression of antioxidant genes at an early time point. BG coating enhances the expression of collagen genes at later time points.

CLINICAL SIGNIFICANCE

Adding 10 wt% Zn to BG could enhance the environment around implant abutments by providing antibacterial, antioxidant, and anti-fibrotic effects, having potential for clinical use.

The Impact of Peri-Implant Diseases on the General Status of Patients with Cardiovascular Diseases: A Literature Review

BACKGROUND AND OBJECTIVES

The aim of this study is to connect peri-implantitis to cardiovascular diseases, following the association found between periodontitis and cardiovascular conditions in recent years.

MATERIALS AND METHODS

PubMed, Scopus, Web of Science online databases were searched up to June 2023, with the exclusion criteria being research written in a language other than English. The MeSH search items were as follows: ["peri-implant health OR peri-implantitis OR peri-implant mucositis OR peri-implant disease"] AND ["cardiovascular diseases"]. Patient/population (P), intervention (I), comparison (C), outcome (O) framework questions were followed to identify the clinical evidence for the systematic review. Only clinical studies that used a control group to compare the relationship between cardiovascular diseases and peri-implantitis were selected.

RESULTS

A total of 118 studies were identified through electronic search of the keywords. After removing duplicates, there were 76 records to be screened. Upon exclusion of ineligible titles and abstracts, 27 studies remained for evaluation. Finally, 23 studies were excluded for not meeting the inclusion criteria, leaving 4 studies to be included in the qualitative analyses.

CONCLUSIONS

This study found there is a linear association between mucosal/gingival inflammation and carotid intima-media thickness test (c-IMT) values. Peri-implant mucosal inflammation could be a contributor to the vascular disease burden of an individual; further specific clinical studies should be performed in order to demonstrate this connection.

The Microbiome of Peri-Implantitis: A Systematic Review of Next-Generation Sequencing Studies

(1) Introduction: Current evidence shows that mechanical debridement augmented with systemic and topical antibiotics may be beneficial for the treatment of peri-implantitis. The microbial profile of peri-implantitis plays a key role in identifying the most suitable antibiotics to be used for the treatment and prevention of peri-implantitis. This systematic review aimed to summarize and critically analyze the methodology and findings of studies which have utilized sequencing techniques to elucidate the microbial profiles of peri-implantitis. (2) Results: Fusobacterium, Treponema, and Porphyromonas sp. are associated with peri-implantitis. Veillonella sp. are associated with healthy implant sites and exhibit a reduced prevalence in deeper pockets and with greater severity of disease progression. Streptococcus sp. have been identified both in diseased and healthy sites. Neisseria sp. have been associated with healthy implants and negatively correlate with the probing depth. Methanogens and AAGPRs were also detected in peri-implantitis sites. (3) Methods: The study was registered with the International Prospective Register of Systematic Reviews (PROSPERO) (CRD42023459266). The PRISMA criteria were used to select articles retrieved from a systematic search of the Scopus, Cochrane, and Medline databases until 1 August 2023. Title and abstract screening was followed by a full-text review of the included articles. Thirty-two articles were included in the final qualitative analysis. (4) Conclusions: A distinct microbial profile could not be identified from studies employing sequencing techniques to identify the microbiome. Further studies are needed with more standardization to allow a comparison of findings. A universal clinical parameter for the diagnosis of peri-implantitis should be implemented in all future studies to minimize confounding factors. The subject pool should also be more diverse and larger to compensate for individual differences, and perhaps a distinct microbial profile can be seen with a larger sample size.

A pattern of microbiological colonization of orthodontic miniscrew implants

INTRODUCTION

Current orthodontic literature reveals a lack of studies on bacterial colonization of orthodontic miniscrew implants (MSI) and their role in the stability of MSI. This study aimed to determine the pattern of microbiological colonization of miniscrew implants in 2 major age groups, to compare it with the microbial flora of gingival sulci in the same group of patients and to compare microbial flora in successful and failed miniscrews.

METHODS

The study involved 102 MSI placed in 32 orthodontic subjects in 2 age groups: (1) aged ≤14 years and (2) aged >14 years. Gingival and peri-mini implant crevicular fluid samples were collected using sterile paper points (International Organization for Standardization no. 35) >3 months and processed by conventional microbiologic culture and biochemical techniques. A microbiologist characterized and identified the bacteria, and the results were subjected to statistical analysis.

RESULTS

Initial colonization was reported within 24 hours, with Streptococci being the dominant colonizer. The relative proportion of anaerobic bacteria over aerobic bacteria increased over time in peri-mini implant crevicular fluid. Group 1 had greater Citrobacter (P = 0.036) and Parvimonas micra (P = 0.016) colonizing MSI than group 2. Failed MSI showed a significantly higher presence of Parvimonas micra (P = 0.008) in group 1 and Staphylococci (P = 0.008), Enterococci (P = 0.011), and Parvimonas micra (P <0.001) in group 2.

CONCLUSIONS

Microbial colonization around MSI is established within 24 hours. Compared to gingival crevicular fluid, peri-mini implant crevicular fluid is colonized by a higher proportion of Staphylococci, facultative enteric commensals and anaerobic cocci. The failed miniscrews showed a higher proportion of Staphylococci, Enterobacter, and Parvimonas micra, suggesting their possible role in the stability of MSI. The bacterial profile of MSI varies with age.

Antimicrobial photodynamic therapy against oral biofilm: influencing factors, mechanisms, and combined actions with other strategies

Oral biofilms are a prominent cause of a wide variety of oral infectious diseases which are still considered as growing public health problems worldwide. Oral biofilms harbor specific virulence factors that would aggravate the infectious process and present resistance to some traditional therapies. Antimicrobial photodynamic therapy (aPDT) has been proposed as a potential approach to eliminate oral biofilms via in situ-generated reactive oxygen species. Although numerous types of research have investigated the effectiveness of aPDT, few review articles have listed the antimicrobial mechanisms of aPDT on oral biofilms and new methods to improve the efficiency of aPDT. The review aims to summarize the virulence factors of oral biofilms, the progress of aPDT in various oral biofilm elimination, the mechanism mediated by aPDT, and combinatorial approaches of aPDT with other traditional agents.

Hydroxyapatite Thin Films of Marine Origin as Sustainable Candidates for Dental Implants

Novel biomaterials with promising bone regeneration potential, derived from rich, renewable, and cheap sources, are reported. Thus, thin films were synthesized from marine-derived (i.e., from fish bones and seashells) hydroxyapatite (MdHA) by pulsed laser deposition (PLD) technique. Besides the physical-chemical and mechanical investigations, the deposited thin films were also evaluated in vitro using dedicated cytocompatibility and antimicrobial assays. The morphological examination of MdHA films revealed the fabrication of rough surfaces, which were shown to favor good cell adhesion, and furthermore could foster the in-situ anchorage of implants. The strong hydrophilic behavior of the thin films was evidenced by contact angle (CA) measurements, with values in the range of 15-18°. The inferred bonding strength adherence values were superior (i.e., ~49 MPa) to the threshold established by ISO regulation for high-load implant coatings. After immersion in biological fluids, the growth of an apatite-based layer was noted, which indicated the good mineralization capacity of the MdHA films. All PLD films exhibited low cytotoxicity on osteoblast, fibroblast, and epithelial cells. Moreover, a persistent protective effect against bacterial and fungal colonization (i.e., 1- to 3-log reduction of E. coli, E. faecalis, and C. albicans growth) was demonstrated after 48 h of incubation, with respect to the Ti control. The good cytocompatibility and effective antimicrobial activity, along with the reduced fabrication costs from sustainable sources (available in large quantities), should, therefore, recommend the MdHA materials proposed herein as innovative and viable solutions for the development of novel coatings for metallic dental implants.

Evaluation of the Photoactivation Effect of 3% Hydrogen Peroxide in the Disinfection of Dental Implants: In Vitro Study

Photoactivation of 3% hydrogen peroxide with a 445 nm diode laser represents a relatively new, insufficiently researched antimicrobial method in the treatment of peri-implantitis. The purpose of this work is to evaluate the effect of photoactivation of 3% hydrogen peroxide with a 445 nm diode laser, and to compare the obtained results with 0.2% chlorhexidine treatment and 3% hydrogen peroxide treatment without photoactivation, in vitro, on the surface of dental implants contaminated with S. aureus and C. albicans biofilms. Previously, 80 infected titanium implants with S. aureus and C. albicans cultures were divided into four groups: G1-negative control (no treatment), G2-positive control (0.2% chlorhexidine), G3 (3% hydrogen peroxide), and G4 (photoactivated 3% hydrogen peroxide). The number of viable microbes in each sample was determined by the colony forming unit (CFU) count. The results were statistically processed and analyzed, showing a statistically significant difference across all groups compared to the negative control (G1), and the absence of a statistically significant difference between groups G1-G3. The new antimicrobial treatment, according to the results, could be worthy of further analysis and research.

Does the Prosthetic Phase of Dental Implants Justify the Prescription of Preventive Antibiotics in Healthy Patients? A Systematic Review

Recently published surveys data show that the routine prescription of preventive antibiotics (PA) in the prosthetic phase of dental implants is more common than might be expected. The present study aimed to answer the PICO (population, intervention, comparison, and outcome) question "In healthy patients starting the implant prosthetic phase, does the prescription of PA compared with not prescribing PA decrease the incidence of infectious complications?" by a systematic literature review. A search was performed in 5 databases. The criteria employed were those described in the PRISMA Declaration. Studies included were those that provided information on the need to prescribe PA in the prosthetic phase of implants, that is, in second-stage surgeries, impression-taking, and prosthesis placement. The electronic search identified 3 studies that met the established criteria. The prescription of PA in the prosthetic phase of implants does not show a justified benefit/risk ratio. Preventive antibiotic therapy (PAT) may be indicated in the second stages or in peri-implant plastic surgery procedures lasting more than 2 hours and/or where soft tissue grafts are used extensively. In these cases, given the current lack of evidence, it is recommended to prescribe 2 g of amoxicillin 1 hour before surgery and, in allergic patients, to prescribe 500 mg of azithromycin 1 hour preoperatively.

Influence of eight debridement techniques on three different titanium surfaces: A laboratory study

OBJECTIVES

Debridement methods may damage implant surfaces. This in vitro study investigated eight debridement protocols across three implant surfaces to assess both biofilm removal and surface alterations.

MATERIAL AND METHODS

One hundred sixty commercially pure titanium discs were treated to simulate commercially available titanium implant surfaces-smooth, abraded and abraded and etched. Following inoculation with whole human saliva to create a mixed species biofilm, the surfaces were treated with eight debridement methods currently used for clinical peri-implantitis (n = 10). This included air abrasion using powders of glycine, sodium bicarbonate and calcium carbonate; conventional mechanical methods-piezoelectric scaler, carbon and stainless steel scalers; and a chemical protocol using 40% citric acid. Following treatment, remaining biofilm was analysed using scanning electron microscopy and crystal violet assays. For statistical analysis, ANOVA was applied (p < 0.05).

RESULTS

All debridement techniques resulted in greater than 80% reduction in biofilm compared with baseline, irrespective of the surface type. Glycine powder delivered through an air polishing system eliminated the most biofilm. Mechanical instruments were the least effective at eliminating biofilm across all surfaces and caused the greatest surface alterations. Citric acid was comparable with mechanical debridement instruments in terms of biofilm removal efficacy. Titanium surfaces were least affected by air abrasion protocols and most affected by mechanical methods.

CONCLUSIONS

Mechanical protocols for non-surgical debridement should be approached with caution. Glycine powder in an air polisher and 40% citric acid application both gave minimal alterations across all implant surfaces, with glycine the superior method in terms of biofilm removal.

The Effect of Microcosm Biofilm Decontamination on Surface Topography, Chemistry, and Biocompatibility Dynamics of Implant Titanium Surfaces

Since the inception of dental implants, a steadily increasing prevalence of peri-implantitis has been documented. Irrespective of the treatment protocol applied for the management of peri-implantitis, this biofilm-associated pathology, continues to be a clinical challenge yielding unpredictable and variable levels of resolution, and in some cases resulting in implant loss. This paper investigated the effect of microcosm biofilm in vitro decontamination on surface topography, wettability, chemistry, and biocompatibility, following decontamination protocols applied to previously infected implant titanium (Ti) surfaces, both micro-rough -Sandblasted, Large-grit, Acid-etched (SLA)-and smooth surfaces -Machined (M). Microcosm biofilms were grown on SLA and M Ti discs. These were treated with TiBrushes (TiB), combination of TiB and photodynamic therapy (PDT), combination of TiB and 0.2%CHX/1%NaClO, plus or minus Ultraviolet-C (UV-C) radiation. Surface topography was evaluated by Scanning Electron Microscopy (SEM) and Laser Surface Profilometry. Surface function was analysed through wettability analysis. Surface chemistry evaluation of the discs was performed under SEM/Energy-dispersive X-ray spectroscopy (EDX) and X-ray photoelectron spectroscopy (XPS). Biocompatibility was tested with the cytocompatibility assay using human osteoblast-like osteosarcoma cell line (MG-63) cells. Elemental analysis of the discs disclosed chemical surface alterations resulting from the different treatment modalities. Titanium, carbon, oxygen, sodium, aluminium, silver, were identified by EDX as the main components of all the discs. Based on the data drawn from this study, we have shown that following the decontamination of Ti surfaces the biomaterial surface chemistry and topography was altered. The type of treatment and Ti surface had a significant effect on cytocompatibility (p = 0.0001). Although, no treatment modality hindered the titanium surface biocompatibility, parameters such as the use of chemical agents and micro-rough surfaces had a higher cytotoxic effect in MG-63 cells. The use of smooth surfaces, and photofunctionalisation of the TiO₂ layer had a beneficial effect on cytocompatibility following decontamination.

A Novel Technique for Disinfection Treatment of Contaminated Dental Implant Surface Using 0.1% Riboflavin and 445 nm Diode Laser—An In Vitro Study

Background: Antimicrobial photodynamic therapy (PDT) has been introduced as a potential option for peri-implantitis treatment. The aim of this study is to evaluate the antimicrobial effect of a novel technique involving a combination of 445 nm diode laser light with 0.1% riboflavin solution (used as a photosensitizing dye) as applied on a bacterial–fungal biofilm formed on implants and to compare the performance of this technique with that of the commonly used combination of 660 nm diode laser with 0.1% methylene blue dye. Methods: An in vitro study was conducted on 80 titanium dental implants contaminated with Staphylococcus aureus (SA) and Candida albicans (CA) species. The implants were randomly divided into four groups: negative control (NC), without surface treatment; positive control (PC), treated with a 0.2% chlorhexidine (CHX)-based solution; PDT1, 660 nm (EasyTip 320 µm, 200 mW, Q power = 100 mW, 124.34 W/cm2, 1240 J/cm2) with a 0.1% methylene blue dye; and PDT2, 445 nm (EasyTip 320 µm, 200 mW, Q power = 100 mW, 100 Hz, 124.34 W/cm2, 1.24 J/cm2) with a 0.1% riboflavin dye. Results: The PDT1 and PDT2 groups showed greater reduction of SA and CA in comparison to the NC group and no significant differences in comparison to the PC group. No statistically significant differences between the PDT1 and PDT2 groups were observed. Conclusions: A novel antimicrobial treatment involving a combination of 445 nm diode laser light with riboflavin solution showed efficiency in reducing SA and CA biofilm formation on dental implant surfaces comparable to those of the more commonly used PDT treatment consisting of 660 nm diode laser light with methylene blue dye or 0.2% CHX treatment.

Influence of titanium implant macrodesign on peri-implantitis occurrence: a cross-sectional study

OBJECTIVES

To assess whether implant macrodesign parameters interacting with implant time in function (Tf) could influence the peri-implantitis occurrence.

MATERIALS AND METHODS

One hundred and two patients (55.17 ± 11.2 years old) with diagnosed early/moderate peri-implantitis around endosseous implants with implant-supported prosthetics reconstruction (n = 139) were recruited. Implant macrodesign (implant shape, thread number, implant collar), clinical parameters (peri-implant probing depth (PPD), clinical attachment level (CAL), keratinised tissue width (KTW), plaque index, bleeding on probe), implant placement localisation and region, and Tf were assessed and compared.

RESULTS

Peri-implantitis occurred approximately 6.1 ± 3.38 years after implant loading. There was a significant positive correlation between the implant macrodesign and Tf. Peri-implantitis rates were statistically significantly higher in implants with a cylindric shape and triple-thread in the posterior part of the mandible (p = 0.037 and 0.012, respectively). The thread number and implant shape interacting with Tf showed statistically significant influences on CAL and PPD increase (p < 0.05). Results indicated a statistically positive interaction between Tf and KTW decrease around the implants with microthreaded collar (p < 0.001).

CONCLUSION

Peri-implantitis might be presented as a time-dependent disease. Implant-based factors, such as Tf and implant macrodesign, could influence peri-implantitis occurrence, exacerbate clinical parameters, and promote progressive bone loss.

CLINICAL RELEVANCE

Peri-implantitis can be affected by implant macrodesign and Tf. The implant body shape, thread number, and design of the implant collar may be considered peri-implantitis-related risk indicators that should be taken into account in proper implant planning and therapy.

Pilot Study of Use of Nitric Oxide in Monitoring Multiple Dental Foci in Oral Cavity—A Case Report

Background: The most common cause of implant loss and deteriorating restoration aesthetics is infection and chronic inflammation of the tissues around the implants. Inflammation in the oral cavity, confirmed by clinical and histopathological examination and determination of exhaled nitric oxide, is a situation which may cause the complications on the whole human body. Elimination of the patology in the oral cavity in some cases is the only resonable treatment. The aims and objectives of our work is to present a gradual treatment of advanced infalmmation and present huge reduction stamp of inflammation measured with marker nitric oxide (NO) in exhaled air. Materials and Methods: Simple treatment containing elimantion of pathology in the oral cavity was conducted. Patient that came to the dental practice suffered from the inflammation caused by lack of proper hygiene. First aid in this situation was to eliminate the inflammation which may affect negatively for general health. At first visit full hygienization was performed, at the second visit roots of abutment teeth and implants were removed under local anesthesia along with cystic changes. Results: The hygiene precedures and extraction of the unsteady inflammationprosthetic restorations significantly decreased the level of NO in exhaled air. Conclusions: During the examination of the patient coming to the dental practice great attention should be paid to the coexistence of pathologies related to the oral cavity. Omission of a dental examination and possible elimination of odontogenic foci may affect the implication of the results of general diagnostics and subsequent treatment. Measuring the level of NO on exhaled air seems to be useful diagnostic method.

Thermoresponsive sol-gel containing probiotic's cell free supernatant for dental caries prophylaxis

Background

Lactobacillus rhamnosus SD11 is a probiotic derived from the human oral cavity and has potential being used for dental prophylaxis. The cell free supernatant (CFS) of L. rhamnosus SD11 has good antimicrobial and antioxidant effects.

Aim

This study aimed to incorporate CFS of the probiotic into thermoresponsive copolymers to create a sol–gel formulation.

Methods

The sol–gel formulation was developed using Poloxamer 407 as the main polymer, which was mixed with natural polymers such as gellan gum, sodium alginate, and xyloglucan in different proportions. The sol–gel formulations were characterized based on their physicochemical parameters such as appearance, pH, viscosity, flow-ability in low temperature, antioxidant and antibacterial activity. An in vitro release study was performed using Franz’s diffusion cell and the stability was determined under freeze-thaw cycle conditions.

Results

The combination of 15% w/v of poloxamer 407 with 0.5% w/v of sodium alginate was the best sol–gel formulation to deliver the CFS of the probiotic.

Conclusion

This study was successful in creating a sol–gel formulation using a thermoresponsive copolymer, that could efficiently deliver CFS of the probiotic L. rhamnosus SD11.

Is Penicillin Allergy a Risk Factor for Early Dental Implant Failure? A Systematic Review

The prescription of preventive antibiotics in dental implant treatments reduces the incidence of early failures. This study has focused mainly on the influence of amoxicillin, which is contraindicated in penicillin-allergic patients. The present systematic review aimed to determine whether penicillin-allergic patients have a higher risk of implant failure compared to non-allergic patients. An electronic search was performed on Medline and Web of Science using the following MeSH terms: (penicillin allergy OR clindamycin OR erythromycin OR azithromycin OR metronidazole) AND (dental implant OR dental implant failure OR dental implant complications). The criteria employed were those described in the PRISMA^® Declaration. Only five articles were included that analyzed the failure rates of implants placed in penicillin-allergic patients who were prescribed clindamycin compared to non-allergic patients who were prescribed amoxicillin. With the limitations of this study, it is not possible to state that penicillin allergy per se constitutes a risk factor for early dental implant failure as most of the studies included self-reported allergic patients. Clindamycin has been associated with a significantly elevated risk of failure and an up to six times increased risk of infection. Immediate implants also have a 5.7 to 10 times higher risk of failure.

Counter-Acting Candida albicans-Staphylococcus aureus Mixed Biofilm on Titanium Implants Using Microbial Biosurfactants

This study aimed to grow a fungal-bacterial mixed biofilm on medical-grade titanium and assess the ability of the biosurfactant R89 (R89BS) coating to inhibit biofilm formation. Coated titanium discs (TDs) were obtained by physical absorption of R89BS. Candida albicans-Staphylococcus aureus biofilm on TDs was grown in Yeast Nitrogen Base, supplemented with dextrose and fetal bovine serum, renewing growth medium every 24 h and incubating at 37 °C under agitation. The anti-biofilm activity was evaluated by quantifying total biomass, microbial metabolic activity and microbial viability at 24, 48, and 72 h on coated and uncoated TDs. Scanning electron microscopy was used to evaluate biofilm architecture. R89BS cytotoxicity on human primary osteoblasts was assayed on solutions at concentrations from 0 to 200 μg/mL and using eluates from coated TDs. Mixed biofilm was significantly inhibited by R89BS coating, with similar effects on biofilm biomass, cell metabolic activity and cell viability. A biofilm inhibition >90% was observed at 24 h. A lower but significant inhibition was still present at 48 h of incubation. Viability tests on primary osteoblasts showed no cytotoxicity of coated TDs. R89BS coating was effective in reducing C. albicans-S. aureus mixed biofilm on titanium surfaces and is a promising strategy to prevent dental implants microbial colonization.

Metabolites of the Oral Microbiome: Important Mediators of Multi-Kingdom Interactions

The oral cavity hosts over 700 different microbial species that produce a rich reservoir of bioactive metabolites critical to oral health maintenance. Over the last two decades, new insights into the oral microbiome and its importance in health and disease have emerged mainly due to the discovery of new oral microbial species using next-generation sequencing (NGS). This advancement has revolutionized the documentation of unique microbial profiles associated with different niches and health/disease states within the oral cavity and the relation of the oral bacteria to systemic diseases. However, less work has been done to identify and characterize the unique oral microbial metabolites that play critical roles in maintaining equilibrium between the various oral microbial species and their human hosts. This article discusses the most significant microbial metabolites produced by these diverse communities of oral bacteria that can either foster health or contribute to disease. Finally, we shed light on how advances in genomics and genome mining can provide a high throughput platform for discovering novel bioactive metabolites derived from the human oral microbiome to tackle emerging human infections and systemic diseases.

Effectivity of homecare and professional biofilm removal procedures on initial supragingival biofilm on laser-microtextured implant surfaces in an ex vivo model

Background

The aim of the current study was the evaluation of initial biofilm adhesion and development on laser-microtextured implant collar surfaces and the examination of effectivity of different biofilm management methods.

Methods

Initial biofilm formation was investigated on hydrophobic machined and laser-microtextured (Laser-Lok) titanium surfaces and hydrophobic machined and laser-microtextured (Laser-Lok) titanium aluminium vanadium surfaces and compared to hydrophobic smooth pickled titanium surfaces, hydrophilic smooth and acid etched titanium surfaces, hydrophobic sandblasted large grid and acid etched titanium surfaces (titanium Promote) via erythrosine staining and subsequent histomorphometrical analysis and scanning electron microscopic investigations. After decontamination procedures, performed via tooth brushing and glycine powder blasting, clean implant surface was detected via histomorphometrical analysis.

Results

After 24 h mean initial plaque area was detected in the following descending order: smooth pickled titanium > titanium Promote > hydrophilic smooth and acid etched titanium > Laser-Lok titanium > Laser-Lok titanium aluminium vanadium. The same order was determined after 48 h of biofilm formation. After glycine powder blasting all samples depicted almost 100% clean implant surface. After tooth brushing, Laser-Lok titanium (67.19%) and Laser-Lok titanium aluminium vanadium (69.80%) showed significantly more clean implant surface than the other structured surfaces, hydrophilic smooth and acid etched titanium (50.34%) and titanium Promote (33.89%). Smooth pickled titanium showed almost complete clean implant surface (98.84%) after tooth brushing.

Conclusions

Both Laser-Lok surfaces showed less initial biofilm formation after 24 and 48 h than the other implant surfaces. In combination with the significant higher clean implant surfaces after domestic decontamination procedure via tooth brushing, both Laser-Lok surfaces could be a candidate for modified implant and abutment designs, especially in transmucosal areas.

Construction and performance evaluation of a sustained release implant material polyetheretherketone with antibacterial properties

OBJECTIVE

This study aimed to construct a tightly binding antibiotic sustained release system on the polyetheretherketone (PEEK) surface and investigate the cellular activity and antibacterial properties of the new oral implant materials.

METHODS

Low-temperature argon plasma under certain parameters was used to prepare P-PEEK with nano-topology, and chemical deposition technology was adopted to form a polydopamine (PDA) coating on the PEEK surface to build a biological binding platform, PDA/P-PEEK. Subsequently, vancomycin gelatin nanoparticles (Van-GNPs) were prepared by two-step desolvation method. Finally, Van-GNPs were combined with PEEK implant material surface to form a new composite material, Van-GNPs/PEEK. scanning electron microscope (SEM), atomic force microscope (AFM), energy dispersive spectrometer (EDS), and contact angle tester were used to comprehensively characterize the materials. The in vitro release test of Van was performed by dynamic dialysis with ultraviolet spectrophotometer. The cell cytotoxicity and adhesion tests were studied by mouse embryonic osteoblasts. The antibacterial properties were evaluated by bacterial adhesion test, plate colony counting, and antimicrobial ring test with Staphylococcus aureus and Streptococcus mutans.

RESULTS

PEEK was treated with low-temperature argon plasma and attached to PDA to form a biological binding platform. The synthesized Van-GNPs were smooth, round, with uniform particle size distribution, and bound to PEEK to form a new composite material, which can release Van constantly. Cell experiments showed that Van-GNPs/PEEK had no cytotoxicity and had good interaction with osteoblasts. Bacterial experiments showed that surface conjugation with Van-GNPs could significantly improve the antibacterial performance of PEEK against S. aureus and S. mutans.

SIGNIFICANCE

This study demonstrated that Van-GNPs/PEEK have good cellular compatibility and autonomous antibacterial properties, which provide a theoretical basis for the wide application of PEEK in the field of stomatology.

Cocktail of carbohydrases from Aspergillus niger: an economical and eco-friendly option for biofilm clearance from biopolymer surfaces

Biofilm formation on both biotic and abiotic surfaces accounts for a major factor in spread of antimicrobial resistance. Due to their ubiquitous nature, biofilms are of great concern for environment as well as human health. In the present study, an integrated process for the co-production of a cocktail of carbohydrases from a natural variant of Aspergillus niger was designed. The enzyme cocktail was found to have a noteworthy potential to eradicate/disperse the biofilms of selected pathogens. For application of enzymes as an antibiofilm agent, the enzyme productivities were enhanced by statistical modelling using response surface methodology (RSM). The antibiofilm potential of the enzyme cocktail was studied in terms of (i) in vitro cell dispersal assay (ii) release of reducing sugars from the biofilm polysaccharides (iii) the effect of enzyme treatment on biofilm cells and architecture by confocal laser scanning microscopy (CLSM). Potential of the enzyme cocktail to disrupt/disperse the biofilm of selected pathogens from biopolymer surfaces was also assessed by field emission scanning electron microscopy (FESEM) analysis. Further, their usage in conjunction with antibiotics was assessed and it was inferred from the results that the use of enzyme cocktail augmented the efficacy of the antibiotics. The study thus provides promising insights into the prospect of using multiple carbohydrases for management of heterogeneous biofilms formed in natural and clinical settings.

Staphylococcus aureus Interferes with Streptococci Spatial Distribution and with Protein Expression of Species within a Polymicrobial Oral Biofilm

We asked whether transient Staphylococcus aureus in the oral environment synergistically interacts with orally associated bacterial species such as Actinomyces oris, Candida albicans, Fusobacterium nucleatum, Streptococcus oralis, Streptococcus mutans, and Veillonella dispar (six-species control biofilm 6S). For this purpose, four modified biofilms with seven species that contain either the wild type strain of the S. aureus genotype (USA300-MRSA WT), its isogenic mutant with MSCRAMM deficiency (USA300-MRSA ΔMSCRAMM), a methicillin-sensitive S. aureus (ST72-MSSA-) or a methicillin-resistant S. aureus (USA800-MRSA) grown on hydroxyapatite disks were examined. Culture analyses, confocal-laser-scanning microscopy and proteome analyses were performed. S. aureus strains affected the amount of supragingival biofilm-associated species differently. The deletion of MSCRAMM genes disrupted the growth of S. aureus and the distribution of S. mutans and S. oralis within the biofilms. In addition, S. aureus caused shifts in the number of detectable proteins of other species in the 6S biofilm. S. aureus (USA300-MRSA WT), aggregated together with early colonizers such as Actinomyces and streptococci, influenced the number of secondary colonizers such as Fusobacterium nucleatum and was involved in structuring the biofilm architecture that triggered the change from a homeostatic biofilm to a dysbiotic biofilm to the development of oral diseases.

Curcumin Nanocrystals: Production, Physicochemical Assessment, and In Vitro Evaluation of the Antimicrobial Effects against Bacterial Loading of the Implant Fixture

Background: This study aimed to prepare and study physicochemical properties as well as the antibacterial action of curcumin nanocrystals inside the implant fixture against Escherichia coli (E. coli), Staphylococcus aureus (S. aureus), and Enterococcus faecalis (E. faecalis). Methods: Curcumin nanocrystals were prepared via precipitation combined with the spray drying method. The produced curcumin nanocrystals were characterized by dynamic light scattering (DLS), scanning electron microscopy (SEM), powder X-ray diffraction (PXRD), and Fourier transform infrared spectroscopy (FTIR). Moreover, the in vitro antimicrobial effect of curcumin nanocrystals inside the implant fixture was assessed against E. coli, S. aureus, and E. faecalis. All implant-abutment assemblies were immersed in bacterial suspensions and were incubated at 24, 48, and 72 h. The contents of each implant were cultured to count the colony of bacteria at 37 °C for 24 h. Results: The prepared curcumin nanocrystals with a mean particle size of 95 nm and spherical morphology exhibited a removal rate of 99.99% for all bacteria. In addition, the colony-forming unit (CFU) of bacteria in exposure to nanocrystals significantly was reduced (p < 0.010) by increasing the time. Conclusions: Curcumin nanocrystals can be used inside the implant fixture as an antimicrobial agent in order to more stabilization of the implant.

Bioactive Healing Abutment as a Potential Tool for the Treatment of Peri-Implant Disease—In Vitro Study

The common use of dental implants for dental reconstruction poses new treatment challenges for physicians, peri-implantitis being a particularly difficult one. Micro-organisms, including drug-resistant Staphylococcus spp. strains, play a crucial role in the etiology of peri-implantitis. In this paper, the authors assess the efficacy of a bioactive healing abutment (BHA) of their own design for the local release of antibiotics as a potential tool for the treatment of peri-implant disease. BHA filled with a collagen material, combined with the antibiotics clindamycin and tetracycline, was tested in vitro by disk diffusion assay. Antibacterial activity was observed for the chosen Staphylococcus aureus and Staphylococcus epidermidis bacterial strains. In addition, the impact of titanium discs (which were used to make the BHA) was monitored. The results show that the zone diameter breakpoints for BHA are higher than those of standard absorbent paper discs in both tested strains for both tested antibiotics. This work demonstrates that the proposed BHA can serve as an effective and precise drug carrier. The release of antibiotics from the described implant device is easy to control and allows for an effective local antibacterial in vitro treatment. The procedure is inexpensive, easy to perform, and repeatable.

Antibacterial Properties of Nano-Ag Coating on Healing Abutment: An In Vitro and Clinical Study

Peri-implantitis is an inflammatory disease with a relevant focus on the long-term success of dental implants and implant-supported prostheses. The present study focuses on the antibacterial effect of the silver nanoparticle and investigated the suppression of dental plaque adhesion on implant abutment and/or superstructure by micro-wave assistant nanosilver coating in vivo and in vitro. Nanosilver coating on pure titanium was prepared by microwave-assisted synthesis, and characterized by scanning electron microscopy and energy-dispersive X-ray spectroscopy. In vitro studies were conducted to analyze biocompatibility using MTS assay and fluorescence microscopy with human gingival fibroblasts to evaluate antibacterial activity. During the in vivo study, nanosilver coating was applied to the healing abutments, and the prevention of plaque accumulation on nanosilver coating was confirmed by a split-mouth randomized clinical trial. The aggregation of nano-sized particles was found on the titanium surface with an antibacterial effect. The coating had no cytotoxic effect on human gingival fibroblasts. The result of the clinical trial showed that the coating suppressed the dental plaque adhesion on the healing abutments. Nanosilver coating is a promising material with antibacterial properties and can be used for implant abutments and prostheses for preventing peri-implantitis.

The Microbiome of Peri-Implantitis: A Systematic Review and Meta-Analysis

This review aimed to systematically compare microbial profiles of peri-implantitis to those of periodontitis and healthy implants. Therefore, an electronic search in five databases was conducted. For inclusion, studies assessing the microbiome of peri-implantitis in otherwise healthy patients were considered. Literature was assessed for consistent evidence of exclusive or predominant peri-implantitis microbiota. Of 158 potentially eligible articles, data of 64 studies on 3730 samples from peri-implant sites were included in this study. Different assessment methods were described in the studies, namely bacterial culture, PCR-based assessment, hybridization techniques, pyrosequencing, and transcriptomic analyses. After analysis of 13 selected culture-dependent studies, no microbial species were found to be specific for peri-implantitis. After assessment of 28 studies using PCR-based methods and a meta-analysis on 19 studies, a higher prevalence of Aggregatibacter actinomycetemcomitans and Prevotella intermedia (log-odds ratio 4.04 and 2.28, respectively) was detected in peri-implantitis biofilms compared with healthy implants. Actinomyces spp., Porphyromonas spp. and Rothia spp. were found in all five pyrosequencing studies in healthy-, periodontitis-, and peri-implantitis samples. In conclusion, the body of evidence does not show a consistent specific profile. Future studies should focus on the assessment of sites with different diagnosis for the same patient, and investigate the complex host-biofilm interaction.

Experimental mucositis/gingivitis in persons aged 70 or over: microbiological findings and prediction of clinical outcome

OBJECTIVES

To assess in persons aged 70 years or older the microbiological alterations occurring around implants and natural teeth during and after 3 weeks of undisturbed plaque accumulation. Furthermore, to test the predictive value of several markers at baseline for the extent of inflammation around implants and teeth after this period.

MATERIALS AND METHODS

Twenty partially edentulous participants with titanium implants refrained from oral hygiene practices while being clinically monitored in weekly intervals for 21 days. Teeth and implants were then cleaned, oral hygiene resumed, and the participants were further monitored. Levels of six subgingival plaque microorganisms, the plaque index (PI), and the gingival index (GI) were assessed before (baseline), during (days 0, 7, 14, 21), and after plaque accumulation (days 28, 42). Six microorganisms; demographic and clinical variables at day 0 were further evaluated as potential predictors for presence of GI > 1 at days 21 and 28.

RESULTS

The detection frequency of the selected bacteria did not differ between implants and teeth at any time point. Bacteria counts decreased in the preparatory phase and increased in the plaque accumulation phase. Patterns observed at implants and teeth were similar. Only Parvimonas micra at day 21 reached significantly higher counts at implants than teeth. For the prediction of clinical outcome at day 21, in the multivariable model, only implant vs. tooth was significant indicator for the primary outcome (p = 0.01).

CONCLUSIONS

Overall, the analysis of subgingival/submucosal samples revealed only minor differences between implants and teeth during the development and resolution of inflammation.

CLINICAL RELEVANCE

Within the limitations of our study, with plaque accumulation, elders develop more inflammation around implants than around teeth, in spite of similar bacterial profiles.

The Effect of In Vitro Electrolytic Cleaning on Biofilm-Contaminated Implant Surfaces

Purpose: Bacterial biofilms are a major problem in the treatment of infected dental and orthopedic implants. The purpose of this study is to investigate the cleaning effect of an electrolytic approach (EC) compared to a powder-spray system (PSS) on titanium surfaces. Materials and Methods: The tested implants (different surfaces and alloys) were collated into six groups and treated ether with EC or PSS. After a mature biofilm was established, the implants were treated, immersed in a nutritional solution, and streaked on Columbia agar. Colony-forming units (CFUs) were counted after breeding and testing (EC), and control (PSS) groups were compared using a paired sample t-test. Results: No bacterial growth was observed in the EC groups. After thinning to 1:1,000,000, 258.1 ± 19.9 (group 2), 264.4 ± 36.5 (group 4), and 245.3 ± 40.7 (group 6) CFUs could be counted in the PSS groups. The difference between the electrolytic approach (test groups 1, 3, and 5) and PSS (control groups 2, 4, and 6) was statistically extremely significant (p-value < 2.2 × 10⁻¹⁶). Conclusion: Only EC inactivated the bacterial biofilm, and PSS left reproducible bacteria behind. Within the limits of this in vitro test, clinical relevance could be demonstrated.

Microbial Etiology and Antimicrobial Therapy of Peri-implantitis: A Comprehensive Review

Introduction:

Implants have turned out to be a well-established therapy in dental practice for the replacement of missing teeth and restoration of function.

Peri-implant disease denotes the inflammatory condition of surrounding soft and hard tissues.

Two terminologies are covered under the impression of peri-implant pathology; peri-implantitis and mucositis. Peri-implant mucositis is a reversible inflammatory process limited to soft tissues around an implant. Peri-implantitis is an inflammatory condition of hard and soft tissue around the dental implant.

Microbial Etiology:

Bacterial infections are the most common cause of peri-implantitis. It is a variable poly-microbial infection, although generally dominated by Gram-negative anaerobic bacteria Anti-infective therapy should be included in the treatment regime, while treating the peri-implant disease. Antimicrobial therapy includes local debridement, antibiotic therapy and surface decontamination of the implant.

Conclusion:

The current article gives a detailed overview of microbial etiology, antimicrobial therapy and its limitations for the treatment of peri-implant Pathology.

Significant Enrichment and Diversity of the Staphylococcal Arginine Catabolic Mobile Element ACME in Staphylococcus epidermidis Isolates From Subgingival Peri-implantitis Sites and Periodontal Pockets

Staphylococcus aureus and Staphylococcus epidermidis are frequent commensals of the nares and skin and are considered transient oral residents. Reports on their prevalence in the oral cavity, periodontal pockets and subgingivally around infected oral implants are conflicting, largely due to methodological limitations. The prevalence of these species in the oral cavities, periodontal pockets and subgingival sites of orally healthy individuals with/without implants and in patients with periodontal disease or infected implants (peri-implantitis) was investigated using selective chromogenic agar and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. Staphylococcus epidermidis was predominant in all participant groups investigated. Its prevalence was significantly higher (P = 0.0189) in periodontal pockets (30%) than subgingival sites of healthy individuals (7.8%), and in subgingival peri-implantitis sites (51.7%) versus subgingival sites around non-infected implants (16.1%) (P = 0.0057). In contrast, S. aureus was recovered from subgingival sites of 0-12.9% of the participant groups, but not from periodontal pockets. The arginine catabolic mobile element (ACME), thought to enhance colonization and survival of S. aureus, was detected in 100/179 S. epidermidis and 0/83 S. aureus isolates screened using multiplex PCR and DNA microarray profiling. Five distinct ACME types, including the recently described types IV and V (I; 14, II; 60, III; 10, IV; 15, V; 1) were identified. ACME-positive S. epidermidis were significantly (P = 0.0369) more prevalent in subgingival peri-implantitis sites (37.9%) than subgingival sites around non-infected implants (12.9%) and also in periodontal pockets (25%) compared to subgingival sites of healthy individuals (4.7%) (P = 0.0167). To investigate the genetic diversity of ACME, 35 isolates, representative of patient groups, sample sites and ACME types underwent whole genome sequencing from which multilocus sequence types (STs) were identified. Sequencing data permitted ACME types II and IV to be subdivided into subtypes IIa-c and IVa-b, respectively, based on distinct flanking direct repeat sequences. Distinct ACME types were commonly associated with specific STs, rather than health/disease states or recovery sites, suggesting that ACME types/subtypes originated amongst specific S. epidermidis lineages. Ninety of the ACME-positive isolates encoded the ACME-arc operon, which likely contributes to oral S. epidermidis survival in the nutrient poor, semi-anaerobic, acidic and inflammatory conditions present in periodontal disease and peri-implantitis.

Reusing dental implants?: an experimental study for detecting the success rates of re-osseointegration

BACKGROUND

The aim of this study was to histomorphometrically compare the implant-host integration between retrieved implants and new implants.

METHODS

Jaws in 10 male beagle dogs were divided into four groups, and 36 dental implants were inserted into the jaws. In groups 1 and 2, experimental peri-implantitis was induced within 2 months after implant insertion. In group 1, surface decontamination of implants was achieved using air-flow and citric acid. In group 2, implants were sterilized with autoclave after air-flow and citric acid surface decontamination. Subsequently, these implants were inserted in contralateral jaws of the same dogs and a 3-month period was allowed for osseointegration. In group 3, the implants were removed from human jaws due to peri-implantitis and were inserted into dog jaws following surface cleaning protocol and sterilization with autoclave and a 3-month period was allowed for osseointegration. Group 4 was set as the control group. After the osseointegration period, all the animals were sacrificed. The degree of osseointegration in all groups was evaluated by evaluating the ISQ values and by using histomorphometric measurements.

RESULTS

Histological findings showed that bone-implant contact (BIC) percentage (mean ± SD) was 83.39% ± 6.37 in group 1, 79.93% ± 11.83 in group 2, 75.45% ± 9.09 in group 3, and 80.53 ± 5.22 in group 4. Moreover, the resonance frequency analysis (RFA) and ISQ values were similar in all four groups both before and after the implantation.

CONCLUSIONS

The results of this experimental study indicated that there is no significant difference between new dental implants and re-used dental implants with regards to osseointegration around the implant.

In vivo expression of proteases and protease inhibitor, a serpin, by periodontal pathogens at teeth and implants

Porphyromonas gingivalis and Tannerella forsythia secrete proteases, gingipains and KLIKK-proteases. In addition, T. forsythia produces a serpin (miropin) with broad inhibitory spectrum. The aim of this pilot study was to determine the level of expression of miropin and individual proteases in vivo in periodontal and peri-implant health and disease conditions. Biofilm and gingival crevicular fluid (GCF)/ peri-implant sulcular fluid (PISF) samples were taken from healthy tooth and implant sites (n = 10), gingivitis and mucositis sites (n = 12), and periodontitis and peri-implantitis sites (n = 10). Concentration of interleukin-8 (IL-8), IL-1β and IL-10 in GCF was determined by enzyme-linked immunosorbent assay. Loads of P. gingivalis and T. forsythia and the presence of proteases and miropin genes were assessed in biofilm by quantitative PCR, whereas gene expression was estimated by quantitative RT-PCR. The presence of P. gingivalis and T. forsythia, as well as the level of IL-8 and IL-1β, were associated with disease severity in the periodontal and peri-implant tissues. In biofilm samples harboring T. forsythia, genes encoding proteases were found to be present at 72.4% for karilysin and 100% for other KLIKK-protease genes and miropin. At the same time, detectable mRNA expression of individual genes ranged from 20.7% to 58.6% of samples (for forsylisin and miropsin-1, respectively). In comparison with the T. forsythia proteases, miropin and the gingipains were highly expressed. The level of expression of gingipains was associated with those of miropin and certain T. forsythia proteases around teeth but not implants. Cumulatively, KLIKK-proteases and especially miropin, might play a role in pathogenesis of both periodontal and peri-implant diseases.

Controlling Streptococcus mutans and Staphylococcus aureus biofilms with direct current and chlorhexidine

Microbial biofilms formed on biomaterials are major causes of chronic infections. Among them, Gram-positive bacteria Streptococcus mutans and Staphylococcus aureus are important pathogens causing infections associated with dental caries (tooth-decay) and other medical implants. Unfortunately, current antimicrobial approaches are ineffective in disrupting established biofilms and new methods are needed to improve the efficacy. In this study, we report that the biofilm cells of S. mutans and S. aureus can be effectively killed by low-level direct current (DC) and through synergy in concurrent treatment with DC and chlorhexidine (CHX) at low concentrations. For example, after treatment with 28 µA/cm² DC and 50 µg/mL CHX for 1 h, the viability of biofilm cells was reduced by approximately 4 and 5 logs for S. mutans and S. aureus, respectively. These results are useful for developing more effective approaches to control pathogenic biofilms.

Microbiome and Microbial Biofilm Profiles of Peri-Implantitis: A Systematic Review

BACKGROUND

This systematic review assesses microbiologic profiles of peri-implantitis, periodontitis, and healthy implants based on studies that evaluated microbial biofilms and entire microbiomes to establish their similarities and differences.

METHODS

The Medical Literature Analysis and Retrieval System Online via PubMed, Excerpta Medica Database, and Cochrane Central Register of Controlled Trials, were searched without language restrictions through July 30, 2016. Observational studies that evaluated microbial profiles or entire microbiomes of peri-implantitis compared with healthy implants or periodontitis were considered eligible for inclusion. A descriptive summary was created to determine quantity of data and interstudy variations.

RESULTS

Of 126 potentially eligible articles, 26 were included in this study. Twenty-one of these articles evaluated the microbiologic profile of peri-implantitis versus healthy implants or periodontitis using conventional microbiologic techniques. Five articles evaluated the entire microbiome using genomic sequencing. Teeth with periodontitis, healthy implants, or implants with peri-implantitis were colonized by periodontal microorganisms. Porphyromonas gingivalis and especially Prevotella intermedius/nigrescens were often identified at peri-implantitis sites. Peri-implantitis sites were also colonized by uncultivable asaccharolytic anaerobic Gram-positive rods and anaerobic Gram-negative rods, which were not frequently identified in teeth with periodontitis or healthy implants. Opportunistic microorganisms were not found very frequently in peri-implantitis sites.

CONCLUSIONS

Peri-implantitis represents a heterogeneous mixed infection that includes periodontopathic microorganisms, uncultivable asaccharolytic anaerobic Gram-positive rods and other uncultivable Gram-negative rods, and, rarely, opportunistic microorganisms such as enteric rods and Staphylococcus aureus. Sequencing methods that evaluate the entire microbiome improve identification of microorganisms associated with peri-implantitis.

Enhanced antifungal activity by disinfected titanium dioxide nanotubes via reduced nano-adhesion bonds

We have provided evidence that the beneficial effect of super-oxidized water (SOW) disinfected Ti6Al4V-TiO₂ nanotubes (NTs) can reduce bacterial adhesion and biofilm formation. However, the need of antifungal nanostructured surfaces with osteoactive capabilities is an important goal that has been arising for dental implants (DI) applications. Thus, in the present study we isolated and tested the effects of Candida albicans (C. albicans) on disinfected, wetter and nanoroughness NTs compared to a non-modified control. Moreover, we elucidated part of the fungal adhesion mechanism by studying and relating the mycotic adhesion kinetics and the formation of fungal nanoadhesion bonds among the experimental materials, to gain new insight of the fungal-material-interface. Similarly, the initial behavior of human alveolar bone osteoblasts (HAOb) was microscopically evaluated. NTs significantly reduced the yeasts adhesion and viability with non-outcomes of biofilm than the non-modified surface. Cross-sectioning of the fungal cells revealed promoted nano-contact bonds with superior fungal spread on the control alloy interface; meanwhile NTs evidenced decreased tendency along time; suggesting, down-regulation by the nanostructured morphology and the SOW treatment. Importantly, the initial performance of HAOb demonstrated strikingly promoted anchorage with effects of filopodia formation and increased vital cell on NTs with SOW. The present study proposes SOW treatment as an active protocol for synthesis and disinfection of NTs with potent antifungal capability, acting in part by the reduction of nano-adhesion bonds at the surface-fungal interface; opening up a novel route for the investigation of mycotic-adhesion processes at the nanoscale for bone implants applications.

Microbiome of dental implants and its clinical aspect

Although dental implants are most common prosthetic treatment used to replace missing tooth, it gained considerable importance over a decade owing to the availability of advanced imagery techniques that can help in achieving a greater success rate and much better osseointegration. However, the chances that the implanted tooth can be rejected due to inflammation caused by oral microflora still persist. This review gives the viewers an overall idea of the dental implants, role of advanced imaging in implantation and instances of peri-implantitis that occur after implantation process. This review also entails the latest research on the different treatment modalities against peri-implantitis documented in peer-review journals.

Efficacy of Antimicrobial Photodynamic Therapy as an Adjunctive to Mechanical Debridement in the Treatment of Peri-implant Diseases: A Randomized Controlled Clinical Trial

Introduction: The purpose of the present study was to assess the clinical effects of anti-microbial photodynamic therapy (PDT) after closed surface scaling in the treatment of peri-implant diseases. Methods: Ten patients with a total of 15 pairs of dental implants, showing clinical and radiographic signs of peri-implant diseases, were included in this study. In each patient, one implant randomly served as control implant and the other served as test implant. The control implants were treated with closed surface scaling only and the test implants received additionally PDT, using light with a wavelength of 630 nm and intensity of 2000 mw/cm² for 120 seconds after application of photosensitizer in peri-implant sulcus. Clinical parameters were evaluated before and 1.5 and 3 months after treatment. Results: Statistical analysis showed significant differences in probing pocket depth (PPD), clinical attachment loss (CAL), bleeding on probing (BOP), and gingival index (GI) at each time point between the two groups. There were no statistically significant changes with respect to any of the parameters in the control group. Complete resolution of BOP at 3 months was achieved in 100% of test implants. At 1.5 and 3 months, there were significant differences in the mean probing depth and CAL gain measurements at implants in the test group. Conclusion: The present study revealed that adjunctive use of PDT following closed surface scaling could lead to clinical improvement of peri-implant diseases. Further studies are necessary to confirm our results.

Peri-implant disease: what we know and what we need to know

Peri-implant disease is a serious problem that plagues today's dentistry, both in terms of therapy and epidemiology. With the expansion of the practice of implantology and an increasing number of implants placed annually, the frequency of peri-implant disease has greatly expanded. Its clinical manifestations, in the absence of a globally established classification, are peri-implant mucositis and peri-implantitis, the counterparts of gingivitis and periodontitis, respectively.

However, many doubts remain about its features. Official diagnostic criteria, globally recognized by the dental community, have not yet been introduced. The latest studies using metagenomic methods are casting doubt on the assumption of microbial equivalence between periodontal and peri-implant crevices. Research on most of the features of peri-implant disease remains at an early stage; moreover, there is not a commonly accepted treatment for it. In any case, although the evidence so far collected is limited, we need to be aware of the current state of the science regarding this topic to better understand and ultimately prevent this disease.

The predictive value of microbiological findings on teeth, internal and external implant portions in clinical decision making

AIM

The primary aim of this study was to evaluate 23 pathogens associated with peri-implantitis at inner part of implant connections, in peri-implant and periodontal pockets between patients suffering peri-implantitis and participants with healthy peri-implant tissues; the secondary aim was to estimate the predictive value of microbiological profile in patients wearing dental implants using data mining methods.

MATERIAL AND METHODS

Fifty participants included in the present case─control study were scheduled for collection of plaque samples from the peri-implant pockets, internal connection, and periodontal pocket. Real-time polymerase chain reaction was performed to quantify 23 pathogens. Three predictive models were developed using C4.5 decision trees to estimate the predictive value of microbiological profile between three experimental sites.

RESULTS

The final sample included 47 patients (22 healthy controls and 25 diseased cases), 90 implants (43 with healthy peri-implant tissues and 47 affected by peri-implantitis). Total and mean pathogen counts at inner portions of the implant connection, in peri-implant and periodontal pockets were generally increased in peri-implantitis patients when compared to healthy controls. The inner portion of the implant connection, the periodontal pocket and peri-implant pocket, respectively, presented a predictive value of microbiologic profile of 82.78%, 94.31%, and 97.5% of accuracy.

CONCLUSION

This study showed that microbiological profile at all three experimental sites is differently characterized between patients suffering peri-implantitis and healthy controls. Data mining analysis identified Parvimonas micra as a highly accurate predictor of peri-implantitis when present in peri-implant pocket while this method generally seems to be promising for diagnosis of such complex infections.