Comparative biology of chronic and aggressive periodontitis vs. peri-implantitis

Peri-Implantitis Diagnosis and Prognosis Using Biomarkers in Peri-Implant Crevicular Fluid: A Narrative Review

Dental implant diseases, peri-implantitis (PI) and peri-implant mucositis (PIM), have shown wide prevalence in recent studies. Despite the prevalence, diagnosing peri-implant disease (PID) remains challenging as common diagnostic methods of periodontal probing and radiographs may be inaccurate. These methods only document pre-existing destruction rather than current disease activity. Furthermore, there is no current model to predict the progression of PID. Though a predictive model is lacking, biomarkers may offer some potential. Biomarkers are commonly used in medicine to objectively determine disease state, or responses to a therapeutic intervention. Gingival crevicular fluid (GCF) biomarkers have moderate diagnostic validity in periodontitis. Biomarkers in peri-implant crevicular fluid (PICF) also show promising results in regard to their diagnostic and prognostic value. The aim of this review is to summarize the current knowledge of PICF biomarkers in the diagnosis of PID and evaluate their validity to predict disease progression. This review found that PICF studies utilize different methods of sampling and interpretation with varying validity (sensitivity and specificity). A number of promising diagnostic techniques were identified. Commercially available chair-side tests for MMP-8 to diagnose periodontal disease and PID activity are now available. Future directions include proteomics and metabolomics for accurate, site-specific diagnosis and prediction of PID progression. Although more research is needed, this review concludes that the assessment of proinflammatory cytokines (IL-1β, TNFα, MMP-8) in the PICF may be of value to diagnose PI and PIM but current research remains insufficient to indicate whether biomarkers predict peri-implant disease progression.

The influence of nanoporous anodic aluminum oxide on the initial adhesion of Streptococcus mitis and mutans

The use of nanoscale surface modifications offers a possibility to regulate the bacterial adherence behavior. The aim of this study was to evaluate the influence of nanoporous anodic aluminum oxide of different pore diameters on the bacterial species Streptococcus mitis and Streptococcus mutans. Nanoporous anodic aluminum oxide (AAO) surfaces with an average pore diameter of 15 and 40 nm, polished pure titanium and compact aluminum oxide (alumina) samples as reference material were investigated. S. mitis and mutans were evaluated for initial adhesion and viability after an incubation period of 30 and 120 min. After 30 min a significantly reduced growth of S. mitis and mutans on 15 nm samples compared to specimens with 40 nm pore diameter, alumina and titanium surfaces could be observed (p < .001). Even after 120 min incubation there was a significant difference between the surfaces with 15 nm pore diameter and the remaining samples (p < .001). AAO surfaces with a small pore diameter have an inhibitory effect on the initial adhesion of S. mitis and mutans. The use of such pore dimensions in the area of the implant shoulder represents a possibility to reduce the adhesion behavior of these bacterial species.

Biofilm as a risk factor in implant treatment

This article summarizes the microbiological findings at dental implants, drawing distinctions between the peri-implant microbiome and the periodontal microbiome, and summarizes what is known regarding biofilm as a risk factor for specific stages of implant treatment. Targeted microbial analysis is reviewed as well as the latest results from open-ended sequencing of the peri-implant flora. At this time there remains a lack of consensus for a specific microbial profile that is associated with peri-implantitis, suggesting that there may be other factors which influence the microbiome such as titanium surface dissolution. Therapeutic interventions to address the biofilm are presented at the preoperative, perioperative, and postoperative stages. Evidence supports that perioperative chlorhexidine reduces biofilm-related implant complications and failure. Regular maintenance for dental implants is also shown to reduce peri-implant mucositis and implant failure. Maintenance procedures should aim to disrupt the biofilm without damaging the titanium dioxide surface layer in an effort to prevent further oxidation. Evidence supports the use of glycine powder air polishing as a valuable adjunct to conventional therapies for use at implant maintenance visits. For the treatment of peri-implantitis, nonsurgical therapy has not been shown to be effective, and while surgical intervention is not always predictable, it has been shown to be superior to nonsurgical treatment for decontamination of the implant surface that is not covered by bone.

Implant Treatment with 12-Year Follow-Up in a Patient with Severe Chronic Periodontitis: A Case Report and Literature Review

Tooth loss among adults is associated with progressive periodontitis. Implant prosthetic treatment has long been utilized in periodontal patients. Even when the implants are applied, ongoing management of periodontal disease and control of inflammation is necessary to maintain a healthy oral cavity. Lack of appropriate periodontal treatment can result in recurrence of periodontal disease during a maintenance period; loss of the supportive capacity of the periodontal tissues will increase the susceptibility of residual teeth to traumatic force. For this reason, it is worthwhile to improve oral function by applying implants as a fixed device. Here, we report that implant treatment in a patient with generalized severe chronic periodontitis helped maintain the periodontal and peri-implant tissue for a long term. We propose that initial periodontal treatment and ongoing supportive therapy can help maintain implants in patients with severe periodontitis. In addition, we reviewed case reports in the English literature so far.

Achievements in the Topographic Design of Commercial Titanium Dental Implants: Towards Anti-Peri-Implantitis Surfaces

Titanium and its alloys constitute the gold standard materials for oral implantology in which their performance is mainly conditioned by their osseointegration capacity in the host's bone. We aim to provide an overview of the advances in surface modification of commercial dental implants analyzing and comparing the osseointegration capacity and the clinical outcome exhibited by different surfaces. Besides, the development of peri-implantitis constitutes one of the most common causes of implant loss due to bacteria colonization. Thus, a synergic response from industry and materials scientists is needed to provide reliable technical and commercial solutions to this issue. The second part of the review focuses on an update of the recent findings toward the development of new materials with osteogenic and antibacterial capacity that are most likely to be marketed, and their correlation with implant geometry, biomechanical behavior, biomaterials features, and clinical outcomes.

The responses of human gingival fibroblasts to magnesium-doped titanium

The titanium (Ti) implant is widely used in implant dentistry; yet peri-implantitis has always been one of the most common and serious complications. Here, we demonstrated that magnesium-doping would be an effective way of enhancing the integration between implant surfaces and gingival tissues, which is critical to peri-implant health. The magnesium (2.76-6.35 at %) was immobilized onto the titanium substrate by a magnesium plasma immersion ion implantation (Mg-PIII) technique. Mg-PIII treatments did not alter surface topographies of the original titanium substrate but improved its hydrophilicity. The in vitro study including cell viability, adhesion, proliferation, migration, and real-time polymerase chain reaction assays disclosed improved adhesion, proliferation, migration, and extracellular matrix remodeling abilities of human gingival fibroblasts (HGFs) on the magnesium-doped titanium. The results of western blot suggested that the Mg-modified titanium induced the phosphorylation of AKT through the activation of PI3K. Our results revealed that magnesium-doping would potentially enhance soft tissue sealings by promoting cellular functions of HGFs in a dose-dependent manner, boding well for its applications on surfaces of implant necks in early peri-implant soft tissue integrations.

Evaluation of peri-implant condition in periodontally compromised patients

Aims:

The aim of the study is to evaluate the profile of peri-implant tissues in periodontally compromised patients.

Settings and Design:

In vivo – cross sectional study design.

Materials and Methods:

Fifty-eight implants were evaluated, clinically and radiographically, installed in seven individuals treated by the same team of professionals, during the years 1997 and 2005 in a private dental clinic in Vitória, ES, Brazil; that time of data collection, all implants were at least 10 years of functional loading. The variables related to the dental implants evaluated were: visible Plaque Index, Gingival Bleeding Index (GBI), probing pocket depth, bleeding on probing, and bone level, to relate them to the classification of dental implants.

Statistical Analysis Used:

The Chi-square and Kruskal–Wallis test were adopted.

Results:

The total of 58 implants were classified: 11 (18.9%) as healthy and 12 (20.7%) as clinically stable. The other 35 implants (60.4%) had some type of peri-implant inflammation, 20 of them (34.5%) were diagnosed with peri-implant mucositis and 15 (25.9%) with peri-implantitis. Among the variables studied, the results showed statistically significant differences for implant location (P = 0.001) and GBI (P = 0.03). Most of the maxillary implants (85.7%) were classified for some type of peri-implant disease. For the implants which resulted in Score 1 for GBI, most of them (75.0%) were also classified for some type of peri-implant disease.

Conclusions:

Dental implants placed in periodontally compromised patients may have high long-term survival rates. However, most implants were classified with some type of peri-implant inflammation.

A wear-resistant TiO2 nanoceramic coating on titanium implants for visible-light photocatalytic removal of organic residues

An effective treatment for peri-implantitis is to completely remove all the bacterial deposits from the contaminated implants, especially the organic residues, to regain biocompatibility and re-osseointegration, but none of the conventional decontamination treatments has achieve this goal. The photocatalytic activity of TiO₂ coating on titanium implants to degrade organic contaminants has attracted researchers' attention recently. But a pure TiO₂ coating only responses to harmful ultraviolet light. Additionally, the poor coating mechanical properties are unable to protect the coating integrity versus initial mechanical decontamination. To address these issues, a unique TiO₂ nanoceramic coating was fabricated on titanium substrates through an innovative plasma electrolytic oxidation (PEO) based procedure, which showed a disordered layer with oxygen vacancies on the outmost part. As a result, the coating could decompose methylene blue, rhodamine B, and pre-adsorbed lipopolysaccharide (LPS) under visible light. Additionally, the coating showed two-fold higher hardness than untreated titanium and excellent wear resistance against steel decontamination instruments, which could be attributed to the specific micro-structure, including the densely packed nanocrystals and good metallurgical combination. Moreover, the in vitro response of MG63 cells confirmed that the coating had comparable biocompatibility and osteoconductivity to untreated titanium substrates. This study provides a unique coating technique as well as a photocatalytic cleaning strategy to enhance decontamination of titanium dental implants, which will favour the development of peri-implantitis treatments. STATEMENT OF SIGNIFICANCE: The treatment of peri-implantitis is based on the complete removal of bacterial deposits, especially the organic residues, but conventional decontamination treatments are hard to achieve it. The photocatalytic activity of TiO₂ coating on titanium implants to degrade organic contaminants provides a promising strategy for deeper decontamination, but its nonactivation to visible light and poor mechanical properties have limited its application. To address these issues, a unique TiO₂ nanoceramic coating was fabricated on titanium substrates based on plasma electrolytic oxidation. The coating showed enhanced visible-light photocatalytic activity, excellent wear resistance and satisfied biocompatibility. Based on this functional coating, it is promising to develop a more efficient strategy for deep decontamination of implant surface, which will favour the development of peri-implantitis treatments.

Does subgingival bacterial colonization differ between implants and teeth? A systematic review

The aim was of this study was to determine the current weight of evidence for the existence of specific differences between the microbiota of healthy teeth and healthy implants, or of teeth with periodontitis and implants with peri-implantitis. A systematic review was conducted according to the PRISMA statement. The MEDLINE, EMBASE and Cochrane databases were searched up to February 2018 for studies comparing microbiological data of biofilm samples collected from healthy teeth and implants or from teeth with periodontitis and implants with peri-implantitis. The weight of evidence was defined in three categories (strong, moderate and mild/some), according to the difference in number of studies showing statistically significantly higher counts and/or proportions and/or abundance and/or prevalence of microorganisms in health or in disease. Of the 132 articles identified, 8 were included. A wide range of microorganisms were present in different conditions but no microorganisms showed strong, moderate or mild/some evidence for a specific association with either teeth or implants. The results of this systematic review indicated that there is insufficient evidence in the literature to support specific differences between microorganisms colonizing teeth and implants, either in health or in disease.

The modulation of the TREM-1/PGLYRP1/MMP-8 axis in peri-implant diseases

OBJECTIVES

The aim of this study is to investigate the expression of sTREM-1 and its ligand PGLYRP1, as well as the expression of MMP-8 and its inhibitor TIMP-1, in peri-implant diseases. As a secondary aim, we analyzed the influence of the concomitant existence of periodontitis in the expression of these biomarkers.

MATERIALS AND METHODS

This study included 77 patients (29 males and 48 females; mean age 55.0 ± 11.5), 18 having gingivitis, 16 having periodontitis, 20 having mucositis, and 23 having peri-implantitis. Patients were clinically examined, and unstimulated whole saliva was collected. sTREM-1, PGLYRP1, MMP-8, TIMP-1, and MMP-8/TIMP1 ratio were determined by ELISA.

RESULTS

The periodontitis group presented higher probing depth (PD) mean, and higher clinical attachment loss, compared with the other groups. The peri-implantitis group presented higher PD mean in implants compared to the mucositis group. Patients with PD ≥ 6 mm showed significantly higher levels of PGLYRP1, MMP-8, and MMP-8/TIMP-1 ratio than patients with PD < 6 mm. When all four markers were assessed, there were no significant differences between mucositis and peri-implantitis groups. Concomitant periodontitis resulted in higher significant levels of MMP-8 in patients with peri-implant disease.

CONCLUSION

We did not observe significant differences in the levels of the sTREM-1/PGLYRP1/MMP-8 axis between patients with periodontal and peri-implant diseases, suggesting that these markers are also involved in the inflammatory process around implants. Besides, the presence of periodontitis may affect the levels of MMP-8 in patients with peri-implant disease.

CLINICAL RELEVANCE

The sTREM-1/PGLYRP1/MMP-8 axis could be useful as potent markers in periodontal and peri-implant diseases.

Antibacterial Effect of Carbosilane Metallodendrimers in Planktonic Cells of Gram-Positive and Gram-Negative Bacteria and Staphylococcus aureus Biofilm

Antibiotic resistance is currently one of the main threats to public health security. Biofilm formation is a resistance mechanism that is responsible for most human bacterial infections and requires new and effective therapeutic approaches, such as those provided by nanotechnology. In this work, the antibacterial effect of carbosilane metallodendrimers with different metals (copper(II) and ruthenium(II)), ligands (chloride and nitrate) and generations (generation 0, 1 and 2) has been studied using planktonic Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli) bacteria. Furthermore, the ability of the metallodendrimers to avoid the formation of S. aureus biofilms was also evaluated. The results showed a promising biocide activity in both types of planktonic bacteria, especially for first-generation dendrimers, which arises from the metal complexation to the dendrimer. Cu(II) metallodendrimers require lower concentration than Ru(II) counterpart to inhibit the production of S. aureus biofilms, but none produce hemolysis at the inhibitory concentrations and can be safely used as antibacterial agents. In particular, the first-generation Cu(II) metallodendrimer with nitrate ligands displayed the most promising properties to continue with further studies in both planktonic cells and biofilms.

Peri-Implant Disease, a Consensus for Treatment: A Case Study

The aim of this case report was to find common treatment with the use of laser energy to treat failing implants. This article discusses definition of peri-implantitis and how-to diagnosis peri-implantitis. The article shows a case report of treatment with the use of two different lasers.

BMP-2 Gene Delivery-Based Bone Regeneration in Dentistry

Bone morphogenetic protein-2 (BMP-2) is a potent growth factor affecting bone formation. While recombinant human BMP-2 (rhBMP-2) has been commercially available in cases of non-union fracture and spinal fusion in orthopaedics, it has also been applied to improve bone regeneration in challenging cases requiring dental implant treatment. However, complications related to an initially high dosage for maintaining an effective physiological concentration at the defect site have been reported, although an effective and safe rhBMP-2 dosage for bone regeneration has not yet been determined. In contrast to protein delivery, BMP-2 gene transfer into the defect site induces BMP-2 synthesis in vivo and leads to secretion for weeks to months, depending on the vector, at a concentration of nanograms per milliliter. BMP-2 gene delivery is advantageous for bone wound healing process in terms of dosage and duration. However, safety concerns related to viral vectors are one of the hurdles that need to be overcome for gene delivery to be used in clinical practice. Recently, commercially available gene therapy has been introduced in orthopedics, and clinical trials in dentistry have been ongoing. This review examines the application of BMP-2 gene therapy for bone regeneration in the oral and maxillofacial regions and discusses future perspectives of BMP-2 gene therapy in dentistry.

Clinical Evaluation of Three Surgical Modalities in the Treatment of Peri-Implantitis: A Randomized Controlled Clinical Trial

OBJECTIVES

To compare the efficacy of three mechanical procedures for surgically treating peri-implantitis.

MATERIALS AND METHODS

In a randomized, prospective, parallel-group study, 47 patients with peri-implantitis were treated with (a) plastic curettes (n = 15 patients, 25 implants), (b) an air-abrasive device (Perio-Flow^®, n = 16 patients,22 implants), or (c) a titanium brush (Ti-Brush^®, n = 16 patients, 23 implants). Patients were assessed for the following measures at three timepoints (baseline, and three and six months after surgery): plaque index, bleeding on probing, gingival index, probing pocket depth (PPD), relative attachment level, and bone loss. Treatment outcome was considered successful when the implant was still present with PPD ≤ 5 mm, no bleeding on probing, and no further mean bone loss ≥ 0.5 mm.

RESULTS

A greater reduction of gingival index and PPD was observed in the titanium brush group than in the other groups at six months (P < 0.001). Relative attachment level decreased from baseline in each group at three months but was more marked in the titanium brush group (P < 0.001). At six months, there was less bone loss in the titanium brush group than in the plastic curette group (P < 0.001; linear mixed model and Kruskal-Wallis). A successful outcome was observed in 22% of implants in the plastic curette group, 27% in the Perio-Flow^® group, and 33% in the Ti-Brush^® group.

CONCLUSIONS

The titanium brush and glycine air-polishing device were more effective than the other methods, but treatment success remained low. Combining mechanical procedures with antimicrobials and/or antibiotics might be a more effective strategy and warrants careful investigation.

Inhibition of the receptor for advanced glycation inhibits lipopolysaccharide-mediated High mobility group protein B1 and Interleukin-6 synthesis in human gingival fibroblasts through the NF-κB signaling pathway

AIMS

We investigated the effect of a specific inhibitor of the receptor for advanced glycation (FPS-ZM1) against lipopolysaccharide (LPS)-induced increase in expressions of high mobility group protein B1 (HMGB1) and interleukin-6 (IL-6) in human gingival fibroblasts (HGFs). Furthermore, we explored the potential molecular mechanisms and assessed the involvement of the NF-κB pathway in mediating the changes in the expressions of HMGB1 and IL-6 expression in response to LPS and FPS-ZM1.

METHODS

HGFs were cultured with enzymatic digestion-tissue explants method. The proliferation of LPS-stimulated HGFs pretreated with FPS-ZM1 at 24, 48, and 72 h was determined by cell counting kit 8 assay. The expressions of HMGB1 and IL-6 were measured using quantitative polymerase chain reaction and enzyme-linked immunosorbent assay. Western blot analysis was used to assess the expressions of receptor for advanced glycation end products (RAGE) and NF-κB.

RESULTS

LPS enhanced the protein expression of RAGE in HGFs. At the same time, LPS stimulated mRNA and protein expressions of HMGB1 and IL-6 in HGFs. However, pretreatment with FPS-ZM1 attenuated these effects. Pretreatment with FPS-ZM1 (250, 500 nM) significantly inhibited the LPS-induced NF-κB activity.

CONCLUSION

FPS-ZM1 down-regulated the LPS-induced HMGB1 and IL-6 expression in HGFs through blocking NF-κB activation. FPS-ZM1 is a promising therapeutic agent for inflammatory diseases caused by oral bacteria.

Inflammatory Periimplant Diseases and the Periodontal Connection Question

Implant therapy has become a widespread reality in modern dentistry. Nevertheless, dental implants can fail due to different causes, among which inflammatory peri-implant diseases (IPDs) are a major challenge, with prevalences that are much higher than previously believed.Specific searches were undertaken for each question raised between October and November 2017, in the PubMed website database (US National Library of Medicine, National Institutes of Health; Bethesda, Maryland, United States). Only articles written in English and published from 2007 onward were considered initially. The following keywords were used in the searches "periimplantitis (PI)," "periimplant mucositis (PM)," "dental implant failure," "periimplant microbiota," "periodontal microbiota," "implant failure" (no temporal limit), and "foreign body reaction" (no temporal limit). The selection process resulted in the selection of 239 articles that were analyzed in detail in elaborating this review. The reference list was limited to the 47 most relevant articles due to editorial limits of this Journal.Intrinsic differences between natural teeth and dental implants are able to give rise to inflammatory diseases that share only minor and scarcely relevant characters, and would consequently deserve different and specifically designed instruments and strategies, for both diagnosis and therapy.

Intra-oral single-site comparisons of periodontal and peri-implant microbiota in health and disease

OBJECTIVE

Periodontitis and peri-implantitis are oral infectious-inflammatory diseases that share similarities in their pathology and etiology. Our objective was to characterize the single-site subgingival and submucosal microbiomes of implant-rehabilitated, partially dentate Chinese subjects (n = 18) presenting with both periodontitis and peri-implantitis.

MATERIALS AND METHODS

Subgingival/submucosal plaque samples were collected from four clinically distinct sites in each subject: peri-implantitis submucosa (DI), periodontal pocket (DT), clinically healthy (unaffected) peri-implant submucosa (HI), and clinically healthy (unaffected) subgingival sulcus (HT). The bacterial microbiota present was analyzed using Illumina MiSeq sequencing.

RESULTS

Twenty-six phyla and 5,726 operational taxonomic units (OTUs, 97% sequence similarity cutoff) were identified. Firmicutes, Proteobacteria, Fusobacteria, Bacteroidetes, Actinobacteria, Synergistetes, TM7, and Spirochaetes comprised 99.6% of the total reads detected. Bacterial communities within the DI, DT, HI, and HT sites shared high levels of taxonomic similarity. Thirty-one "core species" were present in >90% sites, with Streptococcus infantis/mitis/oralis (HMT-070/HMT-071/HMT-638/HMT-677) and Fusobacterium sp. HMT-203/HMT-698 being particularly prevalent and abundant. Beta-diversity analyses (PERMANOVA test, weighted UniFrac) revealed the largest variance in the microbiota was at the subject level (46%), followed by periodontal health status (4%). Differing sets of OTUs were associated with periodontitis and peri-implantitis sites, respectively. This included putative "periodontopathogens," such as Prevotella, Porphyromonas, Tannerella, Bacteroidetes [G-5], and Treponema spp. Interaction network analysis identified several putative patterns underlying dysbiosis in periodontitis/peri-implantitis sites.

CONCLUSIONS

Species (OTU) composition of the periodontal and peri-implant microbiota varied widely between subjects. The inter-subject variations in subgingival/submucosal microbiome composition outweighed differences observed between implant vs. tooth sites, or between diseased vs. healthy (unaffected) peri-implant/periodontal sites.

Neurogenic inflammation in periimplant and periodontal disease: A case-control split-mouth study

OBJECTIVE

Although the regulatory effects of substance-P (SP), neurokinin-A (NKA), calcitonin gene-linked peptide (CGRP) and neuropeptide-Y (NPY) on periodontal inflammatory responses have been described, the effects of these neuropeptides on healthy and diseased periimplant tissues are not clearly defined.

MATERIALS AND METHODS

Thirty-nine implants loaded at least for 12 months with their symmetrically matching teeth were evaluated and compared by a split-mouth study design. Six study groups were created in this regard as follows: group 1 (healthy periodontal tissues), group 2 (healthy periimplant tissues), group 3 (gingivitis), group 4 (periimplant mucositis), group 5 (periodontitis) and group 6 (periimplantitis). Clinical examinations included Silness-Löe plaque index, Löe-Silness gingival index, bleeding on probing, probing pocket depth and clinical attachment level measurements. Gingival crevicular fluid and periimplant sulcular fluid samples were collected, and the concentrations of neuropeptides were determined by enzyme-linked immunosorbent assay. Their levels and correlations were investigated together with the clinical parameters.

RESULTS

Neuropeptide levels were different in the teeth and implant groups according to the periodontal status (p < 0.001). SP and NKA levels were increased, whereas CGRP and NPY levels were decreased in the diseased states. There were no differences between the neuropeptide levels of matching teeth and implants (groups 1-2, groups 3-4 and groups 5-6; p > 0.05).

CONCLUSION

Our study demonstrated the presence of local neuropeptides in healthy and diseased periimplant tissues. The neurogenic inflammatory responses were also found to be similar in both periimplant and periodontal tissues.

Evaluation of Biological Response of STRO-1/c-Kit Enriched Human Dental Pulp Stem Cells to Titanium Surfaces Treated with Two Different Cleaning Systems

Peri-implantitis-an infection caused by bacterial deposition of biofilm-is a common complication in dentistry which may lead to implant loss. Several decontamination procedures have been investigated to identify the optimal approach being capable to remove the bacterial biofilm without modifying the implant surface properties. Our study evaluated whether two different systems-Ni-Ti Brushes (Brush) and Air-Polishing with 40 µm bicarbonate powder (Bic40)-might alter the physical/chemical features of two different titanium surfaces-machined (MCH) and Ca⁺⁺ nanostructured (NCA)-and whether these decontamination systems may affect the biological properties of human STRO-1⁺/c-Kit⁺ dental pulp stem cells (hDPSCs) as well as the bacterial ability to produce biofilm. Cell morphology, proliferation and stemness markers were analysed in hDPSCs grown on both surfaces, before and after the decontamination treatments. Our findings highlighted that Bic40 treatment either maintained the surface characteristics of both implants and allowed hDPSCs to proliferate and preserve their stemness properties. Moreover, Bic40 treatment proved effective in removing bacterial biofilm from both titanium surfaces and consistently limited the biofilm re-growth. In conclusion, our data suggest that Bic40 treatment may operatively clean smooth and rough surfaces without altering their properties and, consequently, offer favourable conditions for reparative cells to hold their biological properties.

Are There Contraindications for Placing Dental Implants?

There are few absolute contraindications to dental implant placement. Relative contraindications include cognitive decline, American Society of Anesthesiology patient status IV or higher categories, or medical conditions that may jeopardize the life or lifespan of the patient. Precautions for placing dental implants should be viewed with respect to the evidence-based exposures that can contribute to risk of failure, including but not limited to local, behavioral, and medical factors. Risk for dental implant failure increases in association with (1) past history of periodontal disease, (2) bruxism, (3) smoking, and (4) radiation therapy.

Nonsurgical therapy for teeth and implants-When and why?

As periodontal and peri-implant diseases represent opportunistic infections, antiinfective therapy is the method of choice. Correctly performed, the treatment outcomes will include resolution of the inflammation concomitant with shrinkage of the tissues, reflected in reduced probing depths. Depending on the patient data obtained after initial antiinfective therapy, further - mostly surgical - treatment may be rendered to reach the goals of a healthy periodontium and peri-implant tissues. Patient compliance is as important as operator skills for optimal treatment outcomes. Regenerative therapy may be applied in compliant patients and for appropriate defects. This article depicts the historical development of periodontal therapy during the 20th century and addresses the various outcome parameters to be used in daily decision making. Obviously, nonsurgical therapy has gained clinical relevance, resulting in highly satisfactory treatment outcomes in many cases. The critical probing depth above which positive attachment gain is registered varies from one treatment modality to another. It is a concept that helps facilitate decision making for additional therapeutic measures after initial therapy. Treatment of peri-implant mucositis prevents development of peri-implantitis. Hence, nonsurgical treatment of mucositis is frequently performed during the continuous monitoring of oral implants. This chapter of Periodontology 2000 presents evidence for the prevention and therapy of peri-implant diseases.

Surgical Therapy of Peri-Implantitis with Local Minocycline: A 6-Month Randomized Controlled Clinical Trial

The purpose of this study was to determine the clinical, microbial, and radiographic effects of local minocycline combined with surgical treatment of peri-implantitis. Fifty patients with peri-implantitis were recruited, and surgical treatment with the local application of either minocycline or placebo ointment was performed. The application of minocycline was repeated with supragingival debridement at 1, 3, and 6 mo postoperatively. Plaque index, gingival index (GI), probing pocket depth (PPD), and bleeding/suppuration on probing were measured at baseline and 1-, 3-, and 6-mo evaluations. The change in supporting bone level (SBL) measured with cone beam computed tomography was analyzed between baseline and 6 mo. Microbial analysis was performed with real-time polymerase chain reaction. Both groups exhibited improvements in clinical and radiographic measurements after surgical treatment. There was a significant difference in the changes of mean PPD between the test and control groups (2.68 ± 1.73 and 1.55 ± 1.86 mm, respectively, P = 0.039). The changes of mean GI and SBL differed significantly between the groups (ΔGI: 0.83 ± 0.60 and 0.40 ± 0.68; ΔSBL: 0.72 ± 0.56 and 0.31 ± 0.49 mm, respectively, P = 0.026 and 0.014). Treatment success rates (defined as PPD <5 mm, absence of bleeding/suppuration on probing, and no further bone loss) were 66.7% and 36.3% in the test and control groups, respectively. The count of red complex bacteria tended to decrease in both groups until 6 mo; however, no significant intergroup difference was found. None of the patients in the test group carried Porphyromonas gingivalis or Tannerella forsythia at 6 mo. These findings indicate that the repeated local delivery of minocycline combined with surgical treatment provides significant benefits in terms of clinical parameters and radiographic bone fill, with a higher treatment success rate in the short healing period (cris.nih.go.kr KCT0002844).

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.

Investigation of the antibacterial effect of laser irradiation and chemical agent on human oral biofilms contaminated titanium discs

INTRODUCTION

A main challenge in treatment of peri-implant disease is the effective decontamination of the implant surface. This challenge has always been a problem, associated with the treatment of these diseases with regard to the difficulty in removing and eliminating bacterial biofilm from the surface of dental implants, especially rough surfaces. The aim of this in-vivo study was to evaluate the effect of five different antimicrobial methods in reducing bacteria adhering to titanium surfaces.

MATERIALS AND METHODS

In the present in-vivo study, the contaminated discs, except for the negative control group, randomly underwent one of five treatments: Erbium: Yattrium Aluminum Garnet (Er-YAG) laser, plastic curette, 0.12% chlorhexidine, aPDT, and 810 nm diode laser. A pectrophotometer was used to measure Optical Density (OD) in case of aerobic microorganisms. Colony-Forming Units (CFUs) were used for anaerobic bacteria. Then, all the analyses were carried out at a significance level of α = 0.05 through SPSS software.

FINDINGS

One-way analysis of variance (ANOVA) of aerobic bacteria showed a significant difference among 6 groups in terms of OD variations during a 0-24 h time interval (P < 0.001). The results of Kruskal-Wallis test were used to investigate the effect of study methods on anaerobic bacteria after 48 h, and the results showed a significant difference among 6 groups in terms of CFUs (P < 0.001).

CONCLUSION

The results of the present study showed that all five mechanicals (plastic curette), chemical (CHX), laser (810 nm diode and Er: YAG), and aPDT methods could reduce oral biofilms from roughed surfaces of titanium discs. Er: YAG laser and plastic curette had the highest and the lowest effects respectively.

In Vitro Comparison of the Efficacy of Peri-Implantitis Treatments on the Removal and Recolonization of Streptococcus gordonii Biofilm on Titanium Disks

Objective: To compare the efficacy of four commonly used clinical procedures in removing Streptococcus gordonii biofilms from titanium disks, and the recolonization of the treated surfaces. Background: Successful peri-implantitis treatment depends on the removal of the dental biofilm. Biofilm that forms after implant debridement may threaten the success of the treatment and the long-term stability of the implants. Methods:S. gordonii biofilms were grown on titanium disks for 48 h and removed using a plastic curette, air-abrasive device (Perio-Flow®), titanium brush (TiBrush®), or implantoplasty. The remaining biofilm and the recolonization of the treated disks were observed using scanning electron microscopy and quantified after staining with crystal violet. Surface roughness (Ra and Rz) was measured using a profilometer. Results:S. gordonii biofilm biomass was reduced after treatment with Perio-Flow®, TiBrush®, and implantoplasty (all p < 0.05), but not plastic curette (p > 0.05), compared to the control group. Recolonization of S. gordonii after treatment was lowest after Perio-Flow®, TiBrush®, and implantoplasty (all p < 0.05 vs. control), but there was no difference between the plastic curette and the control group (p > 0.05). Ra and Rz values ranged from 1–6 µm to 1–2 µm and did not differ statistically between the control, plastic curette, Perio-Flow, and TiBrush groups. However, the implantoplasty group showed a Ra value below 1 µm (p < 0.01, ANOVA, Tukey). Conclusions: Perio-Flow^®, TiBrush^®, and implantoplasty were more effective than the plastic curette at removing the S. gordonii biofilm and preventing recolonization. These results should influence the surgical management of peri-implantitis.

A doxycycline-treated hydroxyapatite implant surface attenuates the progression of peri-implantitis: A radiographic and histological study in mice

BACKGROUND

Oral rehabilitation with dental implants has become increasingly common; however, the increase of peri-implantitis is a great concern. Doxycycline (DOX) is a widely used antibiotic that inhibits bacteria growth, inflammation, and bone resorption.

OBJECTIVES

To evaluate the progression of peri-implantitis of hydroxyapatite (HA)-coated implants with (5 mg/mL, DOX group) or without (HA group) DOX treatment on the surface.

MATERIALS AND METHODS

The maxillary first molars of 20 male mice were extracted. Eight weeks later, small titanium screw implants coated with thin HA and treated with or without DOX were placed at the extracted sites. Four weeks after implant placement, half of the animals in both groups were sacrificed, and ligatures were placed around the implant necks in the other half. These mice were sacrificed 4 weeks later. The bone around the implants was examined radiologically and histologically.

RESULTS

Four weeks after the ligature placement, the radiographic measurements revealed that peri-implant bone levels of palatal and mesial sites, and histological measurements showed that bone levels of mesial and distal sites in the DOX group were significantly higher than those in the HA group.

CONCLUSIONS

The present results indicating that the DOX-treated HA implant surface attenuates the progression of peri-implantitis.

In vitro evaluation of a multispecies oral biofilm over antibacterial coated titanium surfaces

Peri-implantitis is an infectious disease that affects the supporting soft and hard tissues around dental implants and its prevalence is increasing considerably. The development of antibacterial strategies, such as titanium antibacterial-coated surfaces, may be a promising strategy to prevent the onset and progression of peri-implantitis. The aim of this study was to quantify the biofilm adhesion and bacterial cell viability over titanium disc with or without antibacterial surface treatment. Five bacterial strains were used to develop a multispecies oral biofilm. The selected species represent initial (Streptococcus oralis and Actinomyces viscosus), early (Veillonella parvula), secondary (Fusobacterium nucleatum) and late (Porphyromonas gingivalis) colonizers. Bacteria were sequentially inoculated over seven different types of titanium surfaces, combining different roughness level and antibacterial coatings: silver nanoparticles and TESPSA silanization. Biofilm formation, cellular viability and bacterial quantification over each surface were analyzed using scanning electron microscopy, confocal microscopy and real time PCR. Biofilm formation over titanium surfaces with different bacterial morphologies could be observed. TESPSA was able to significantly reduce the cellular viability when compared to all the surfaces (p < 0.05). Silver deposition on titanium surface did not show improved results in terms of biofilm adhesion and cellular viability when compared to its corresponding non-coated surface. The total amount of bacterial biofilm did not significantly differ between groups (p > 0.05). TESPSA was able to reduce biofilm adhesion and cellular viability. However, silver deposition on titanium surface seemed not to confer these antibacterial properties.

Simplified nonsurgical treatment of peri-implantitis using chlorhexidine and minocycline hydrochloride

Purpose

The present study investigated the outcomes of a newly-developed, simple, and practical nonsurgical treatment modality suitable for most forms of intrabony defects around failing dental implants using intrasulcular delivery of chlorhexidine solution and minocycline hydrochloride (HCl).

Methods

Forty-five dental implants in 20 patients diagnosed with peri-implantitis were included. At baseline and the study endpoint, the probing pocket depth (PPD), clinical attachment level (CAL), and the presence of bleeding on probing (BOP) at 6 sites around each implant were recorded. The radiographic osseous defect morphology at the mesial or distal proximal aspect of each implant was classified as 1) narrow or wide and 2) shallow or deep. For a comparative analysis of bone changes according to the defect morphology, the distance from the implant shoulder to the most coronal bone-to-implant contact point (DIB) at the mesial and distal aspects of each implant was measured at baseline and the endpoint. Patients were scheduled to visit the clinic every 2–4 weeks for intrasulcular irrigation of chlorhexidine and delivery of minocycline HCl.

Results

We observed statistically significant decreases in PPD, CAL, and BOP after treatment. At the endpoint, bone levels increased in all defects, regardless of the osseous morphology of the intrabony defect. The mean DIB change in deep defects was significantly greater than that in shallow defects. Although the mean bone gain in narrow defects was greater than in wide defects, the difference was not statistically significant.

Conclusions

We propose that significant and sustainable improvements in both clinical and radiographic parameters can be expected when intrabony defects around dental implants are managed through a simple nonsurgical approach involving combined intrasulcular chlorhexidine irrigation and local delivery of minocycline HCl.

Titanium as a modifier of the peri-implant microbiome structure

BACKGROUND

Recent data support the implication of accelerated titanium dissolution products in peri-implantitis. It is unknown whether these dissolution products have an effect on the peri-implant microbiome, the target of existing peri-implantitis therapies.

PURPOSE

This study assessed the relationship between the peri-implant microbiome, dissolved titanium levels, and peri-implantitis.

MATERIALS AND METHODS

Clinical, microbiome, and titanium data were collected from a periodontal population having implants in function for 10 years. Clinical examinations were performed, and submucosal plaque samples were collected from the deepest site per implant. An aliquot of the sample was used for 16S rRNA gene sequencing, with the remainder analyzed for titanium quantity using mass spectrometry. Sequences were clustered into taxonomic units at 97% minimum sequence similarity using the QIIME pipeline approach.

RESULTS

Fifteen implants were assessed. According to established case definitions, six had a diagnosis of peri-implantitis; nine were healthy. The genera Streptococcus, Prevotella and Haemophilus characterized peri-implant health. Peri-implantitis was associated with a marked increase in Veillonella. Quantities of dissolved titanium were identified in 40% of sites. Titanium presence was associated with peri-implant disease status (P = .02) and correlated to the first principal component of the microbiome (rho = 0.552) and its alpha-diversity (rho = -0.496). Canonical correlation analyses found that titanium levels, but not health or disease status of the implant, were significantly associated with the microbiota composition (P = .045).

CONCLUSIONS

These findings suggest an association between titanium dissolution products and peri-implantitis and support a role for these products in modifying the peri-implant microbiome structure and diversity.

Early intervention of peri-implantitis and periodontitis using a mouse model

BACKGROUND

Peri-implantitis is an inflammatory response to bacterial biofilm resulting in bone loss and can ultimately lead to implant failure. Because of the lack of predictable treatments available, a thorough understanding of peri-implantitis's pathogenesis is essential. The objective of this study is to evaluate and compare the response of acute induced peri-implantitis and periodontitis lesions after insult removal.

METHODS

Implants were placed in one-month-old C57BL/6J male mice eight weeks post extraction of their left maxillary molars. Once osseointegrated, ligatures were placed around the implants and contralateral second molars of the experimental groups. Controls did not receive ligatures. After one week, half of the ligatures were removed, creating the ligature-retained and ligature-removed groups. Mice were sacrificed at two time points, 5 and 14 days, from ligature removal. The specimens were analyzed via micro-computed tomography and histology.

RESULTS

By 5 and 14 days after ligature removal, the periodontitis group experienced significant bone gain, whereas the peri-implantitis group did not. Histologically, all implant groups exhibited higher levels of cellular infiltrate than any of the tooth groups. Osteoclast numbers increased in peri-implantitis and periodontitis ligature-retained groups and decreased following insult removal. Collagen was overall more disorganized in peri-implantitis than periodontitis for all groups. Peri-implantitis experimental groups revealed greater matrix metalloproteinase-8 and NF-kB levels than periodontitis.

CONCLUSIONS

Implants respond slower and less favorably to insult removal than teeth. Future research is needed to characterize detailed peri-implantitis disease pathophysiology.

Elevated levels of 8-OHdG and PARK7/DJ-1 in peri-implantitis mucosa

BACKGROUND

Reactive oxygen species contribute to periodontal tissue homeostasis under control of anti-oxidative responses. Disruption in this balance induces severe inflammation and extended tissue degradation.

PURPOSE

Aim of this study was to identify the expression levels of nuclear factor, erythroid 2 like 2 (NFE2L2/NRF2), Parkinsonism associated deglycase (PARK7/DJ-1), kelch-like ECH associated protein 1 (KEAP1), and 8-hydroxy-deoxyguanosine (8-OHdG) in peri-implant mucosal tissues affected by peri-implantitis, and to compare the levels to those of periodontally diseased and healthy tissue samples.

METHODS

Tissue biopsies were collected from systemically healthy, non-smoking 12 peri-implantitis patients, 13 periodontitis patients, and 13 periodontally healthy controls. Expression levels of NFE2L2/NRF2, PARK7/DJ-1, KEAP1, and 8-OHdG in tissue samples were analyzed immunohistochemically. Statistical analysis was performed by one-way ANOVA with Tukey's HSD test.

RESULTS

Inflammatory cell infiltration in the connective tissue and loss of architecture in the spinous layer of the epithelium were prominent in peri-implantitis. Proportions of 8-OHdG and PARK7/DJ-1 expressing cells were elevated in both peri-implantitis (P = .025 for 8-OHdG and P = .014 for PARK7/DJ-1) and periodontitis (P = .038 for 8-OHdG and P = .012 for PARK7/DJ-1) groups in comparison with controls. Staining intensities of 8-OHdG and PARK7/DJ-1 were higher in the periodontitis and peri-implantitis groups than in the control (P < .01) groups. There was no difference in the expression levels of NFE2L2/NRF2 between the groups. KEAP1 was not observed in any tissue sample.

CONCLUSIONS

Peri-implantitis is characterized by severe inflammation and architectural changes in the epithelium and connective tissue. The expressions of 8-OHdG and PARK7/DJ-1 are elevated in both peri-implantitis and periodontitis.

Air-Abrasive Disinfection of Implant Surfaces in a Simulated Model of Periimplantitis

INTRODUCTION

This in vitro study aimed to evaluate the ability of air-powder abrasion to decontaminate dental implants.

MATERIALS AND METHODS

Twenty-six implants were inoculated with a Streptococcus sanguinis biofilm media in a novel periimplantitis defect model. Six implants served as controls, and 20 implants were disinfected with either the Cavitron JET Plus or the AIR-FLOW PERIO air-powder abrasion units. Residual bacteria were cultured, and colony forming units (CFUs) were totaled at 24 hours.

RESULTS

As expected, negative control implant cultures showed no evidence of viable bacteria. Bacterial growth was observed on all positive control cultures, whereas only 15% of the experimental cultures displayed evidence of viable bacteria. The average CFU per streak for the positive control was 104 compared with a maximum of 10 and 4 CFUs for the Cavitron JET Plus and AIR-FLOW PERIO, respectively. There was a 99.9% reduction in bacteria for both air-powder abrasion instruments.

CONCLUSION

Air-powder abrasion is an effective technique for the decontamination of dental implants, and the Cavitron JET Plus and AIR-FLOW PERIO are equally successful at eliminating viable bacteria from implant surfaces.

Quantitative measurement of peri-implant bone defects using optical coherence tomography

Purpose

The purpose of this study was to visualize and identify peri-implant bone defects in optical coherence tomography (OCT) images and to obtain quantitative measurements of the defect depth.

Methods

Dehiscence defects were intentionally formed in porcine mandibles and implants were simultaneously placed without flap elevation. Only the threads of the fixture could be seen at the bone defect site in the OCT images, so the depth of the peri-implant bone defect could be measured through the length of the visible threads. To analyze the reliability of the OCT measurements, the flaps were elevated and the depth of the dehiscence defects was measured with a digital caliper.

Results

The average defect depth measured by a digital caliper was 4.88±1.28 mm, and the corresponding OCT measurement was 5.11±1.33 mm. Very thin bone areas that were sufficiently transparent in the coronal portion were penetrated by the optical beam in OCT imaging and regarded as bone loss. The intraclass correlation coefficient between the 2 methods was high, with a 95% confidence interval (CI) close to 1. In the Bland-Altman analysis, most measured values were within the threshold of the 95% CI, suggesting close agreement of the OCT measurements with the caliper measurements.

Conclusions

OCT images can be used to visualize the peri-implant bone level and to identify bone defects. The potential of quantitative non-invasive measurements of the amount of bone loss was also confirmed.

Should implants be considered for patients with periodontal disease?

Dental implants are seen as a good option for replacing missing teeth. The success and survival rates for implants are very high. Concerns are developing about the problem of peri-implantitis. The reports of its prevalence vary but it is noted that the presence of periodontal disease is a risk factor. The issue of peri-implantitis was raised in the House of Lords in 2014. Complaints relating to implants is on the rise with the General Dental Council. Placement of implants in patients with periodontal disease is not a treatment that should be done without a full periodontal assessment and stabilisation of periodontal disease first. This review considers the risk of placing implants in patients with aggressive and chronic periodontitis.