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

When oral health affects overall health: biofilms, dental infections, and emerging antimicrobial strategies

Dental health is a crucial component of overall health, yet it is frequently overlooked in discussions about well-being. This article explores the multifaceted aspects of dental infections, primarily focusing on biofilms formed by pathogenic bacteria such as Streptococcus mutans and Porphyromonas gingivalis. These biofilms contribute to dental caries and periodontal disease, conditions that affect oral health and have systemic consequences. Recent advancements in understanding biofilm formation and interactions have led to novel strategies for prevention and treatment, including using nanoparticles and smart hydrogels designed to disrupt biofilm integrity while promoting biocompatibility with human tissues. Furthermore, the article highlights the potential of natural remedies, including herbal extracts, as adjuncts in maintaining oral hygiene and combating microbial infections. A comprehensive overview of biofilm dynamics, including adhesion, maturation, and dispersion, is presented, alongside discussions on innovative therapeutic approaches addressing the limitations of conventional treatments. Ultimately, this article emphasizes the importance of maintaining dental health in preventing a wide spectrum of health issues, reinforcing that the mouth is a gateway to the body.

Effect of mechanical instrumentation on titanium implant surface properties

OBJECTIVE

To assess the impact of mechanical decontamination using rotary brushes on the surface topography, elemental composition, roughness, and wettability of titanium implant surfaces.

METHODS

Four commercially available rotary brushes were used: Labrida BioClean Brush® (LB), i-Brush1 (IB), NiTiBrush Nano (NiTiB), and Peri-implantitis Brush (PIB). Seventy-five titanium discs with sandblasted, large-grit, acid-etched (SLA) surfaces were randomly assigned to five groups (n = 15): LB, IB, NiTiB, PIB, and a control group. Each disc was treated for 60 seconds with the respective rotary brush according to the manufacturer's instructions. Surface morphology was analysed using Scanning Electron Microscopy (SEM), surface elemental composition with Energy Dispersive X-ray (EDX), surface roughness via optical profilometry, and wettability with a droplet shape analyser.

RESULTS

SEI analysis revealed morphological changes, including scratches, flattening, and loose titanium particles in the IB, PIB, and NiTiB groups, whereas the LB group preserved the original surface morphology. SEM-EDX analysis showed that LB, PIB, and NiTiB groups closely match the control elemental composition. However, IB groups showed significantly different composition. Surface roughness values in the IB, PIB, and NiTiB groups differed significantly from the control (p < 0.05), whereas the LB group had comparable roughness values (p > 0.05). Contact angle measurements indicated enhanced wettability in IB, PIB, and NiTiB groups (p < 0.05), while the LB group exhibited values comparable to the control (p > 0.05).

SIGNIFICANCE

Mechanical decontamination of implant surfaces utilising rotary brushes can alter implant surface properties.

Aptamers in dentistry: diagnosis, therapeutics, and future perspectives

Oral health is essential to general health. The diagnosis of dental diseases and treatment planning of dental care need to be straightforward and accurate. Recent studies have reported the use of aptamers in dentistry to achieve a simple diagnosis and facilitate therapy. Aptamers comprise nucleic acid sequences that possess a strong affinity for their target. Synthesized chemically, aptamers have several advantages, including smaller size, higher stability, and lower immunogenicity compared with monoclonal antibodies. They can be used to detect biomarkers in saliva and the presence of various pathogens, or can be used as a targeted drug delivery system for disease treatment. This review highlights current research on aptamers for dental care, especially the recent progress in oral disease diagnosis and therapeutics. The challenges and unresolved problems faced by the clinical use of aptamers are also discussed. In the future, the clinical applications of aptamers will be further extended to include, for example, dental indications and regenerative dentistry.

Ultrasound-mediated nanomaterials for the treatment of inflammatory diseases

Sterile and infection-associated inflammatory diseases are becoming increasingly prevalent worldwide. Conventional drug therapies often entail significant drawbacks, such as the risk of drug overdose, the development of drug resistance in pathogens, and systemic adverse reactions, all of which can undermine the effectiveness of treatments for these conditions. Nanomaterials (NMs) have emerged as a promising tool in the treatment of inflammatory diseases due to their precise targeting capabilities, tunable characteristics, and responsiveness to external stimuli. Ultrasound (US), a non-invasive and effective treatment method, has been explored in combination with NMs to achieve enhanced therapeutic outcomes. This review provides a comprehensive overview of the recent advances in the use of US-mediated NMs for treating inflammatory diseases. A comprehensive introduction to the application and classification of US was first presented, emphasizing the advantages of US-mediated NMs and the mechanisms through which US and NMs interact to enhance anti-inflammatory therapy. Subsequently, specific applications of US-mediated NMs in sterile and infection-associated inflammation were summarized. Finally, the challenges and prospects of US-mediated NMs in clinical translation were discussed, along with an outline of future research directions. This review aims to provide insights to guide the development and improvement of US-mediated NMs for more effective therapeutic interventions in inflammatory diseases.

Engineering soft-hard tissue interfaces in dental and craniofacial system by spatially controlled bioactivities

The interface between soft and hard tissues is constituted by a gradient change of cell types and matrix compositions that are optimally designed for proper load transmission and injury protection. In the musculoskeletal system, the soft-hard tissue interfaces at tendon-bone, ligament-bone, and meniscus-bone have been extensively researched as regenerative targets. Similarly, extensive research efforts have been made to guide the regeneration of multi-tissue complexes in periodontium. However, the other soft-hard tissue interfaces in the dental and craniofacial system have been somewhat neglected. This review discusses the clinical significance of developing regenerative strategies for soft-hard tissue interfaces in the dental and craniofacial system. It also discusses the research progress in the field focused on bioengineering approaches using 3D scaffolds equipped with spatially controlled bioactivities. The remaining challenges, future perspectives, and considerations for the clinical translation of bioactive scaffolds are also discussed.

The Decision Between Tooth Retention or Replacement with Implants: A Continuing Dilemma

The global adoption of dental implants has significantly reshaped modern dental practices, with the market projected to reach USD 16 billion by 2029. However, despite high success rates, dental implants can still be prone to complications, particularly when underlying causes of tooth loss, such as periodontal disease and bone loss, are not addressed. This paper explores the biological and mechanical considerations in the decision-making process between preserving a tooth through periodontal therapy or opting for extraction and implant placement. It also highlights the importance of a holistic approach that includes assessing the patient's oral health, periodontal status, and the biomechanical factors influencing tooth retention. Periodontal therapy has been proven to be highly effective, with both non-surgical and surgical therapies showing long-term efficacy in preserving natural teeth, especially in the presence of furcation involvement. Studies show that proper periodontal management, including regular maintenance therapy after the active therapy, significantly enhances tooth survival, even in cases of severe periodontitis. In contrast, dental implants, while effective, are not free of complications, mainly inflammatory peri-implant diseases, but also mechanical complications, which can compromise long-term outcomes. The paper reviews clinical studies on implant survival, demonstrating that periodontal therapy can sometimes offer a more cost-effective and biologically sound alternative to implant therapy, especially for teeth with severe attachment loss or furcation involvement. In conclusion, treatment decisions should be based on a comprehensive evaluation of clinical, biological, and patient-specific factors. By integrating regenerative therapies even in more compromised teeth and addressing the root causes of tooth loss, implant rehabilitation can be postponed for many years and offer a cost-effective and successful long-term treatment plan. This approach underscores the importance of individualized care in the evolving landscape of restorative dentistry and implantology.

In vitro evaluation of surface roughness of titanium abutments after air polishing with different abrasive powders

OBJECTIVES

The purpose of this study was to evaluate the effects of air polishing with sodium bicarbonate and erythritol powders on surface roughness and morphological changes in titanium abutments.

METHODS

A total of 45 grade V titanium discs were divided in three groups: Group A (Control) air polished with air/water; Group B, air polished with sodium bicarbonate powder; and Group C, air polished with erythritol powder. After air polishing, the samples' roughness (Sa) in micrometres were analysed with an optical profilometer. The samples' surface morphology study was conducted via scanning electronic microscope (SEM). Data were described using mean and standard deviation of roughness values (Sa). Inferential analysis was performed using the ANOVA multiple comparison test followed by Tukey's post hoc test. Both tests used a 5% level of significance.

RESULTS

After air polishing, average roughness of group A, B and C were 0.036, 0.046 and 0.037 μm, respectively, with statistically significant differences between groups A and B (p < 0.05). No statistically significant differences were found between group A and group C, as well as between group B and C (p > 0.05). As for the morphology analysis, damages to the titanium surface were only observed in group B.

CONCLUSIONS

The study indicates that air polishing with erythritol powder maintains titanium abutment integrity better than sodium bicarbonate, which increased surface roughness and caused damage. Erythritol is preferable for minimizing surface alterations and maintaining morphological stability.

Influence of rheumatoid arthritis on peri-implant diseases: A longitudinal retrospective clinical and radiographic evaluation

BACKGROUND

To investigate the effect of rheumatoid arthritis (RA) on the incidence of peri-implantitis (PI) and peri-implant mucositis (PIM).

METHODS

Radiographic and clinical chart reviews were conducted to measure the probing depth (PD), bleeding on probing, and marginal bone loss (MBL) around the implants to diagnose peri-implant diseases based on the 2017 workshop classification. Values were recorded at the baseline (T0) to the last available chart and radiograph (T1). Maintenance compliance was evaluated. Cases were followed longitudinally to detect the incidence of PI and PIM. Various potential confounders were controlled, including the total radiographic follow-up time, chart-based follow-up time, number of maintenance visits, implant dimensions, history of periodontitis, bone graft, restoration angle, emergence, smoking, and diabetes mellitus. Chi-square and Mann-Whitney tests evaluated categorical and continuous differences. Generalized estimating equations with a Tweedie distribution were applied. Binary logistic regression ascertained the odds ratio for binary outcomes.

RESULTS

A total of 101 patients (50 RA and 51 non-RA) with 124 implants were investigated. The mean follow-up period for the implants was 5.38 ± 2.22 years. Implant survival rate was high at 96%. The RA group demonstrated a significantly higher PI (p = 0.024), while the non-RA group showed a significantly higher PIM (p < 0.001). No significant differences were observed between both groups in implant survival and MBL.

CONCLUSION

Compared to the non-RA group, RA patients demonstrated a similar incidence of MBL and implant survival rates and a significantly lower incidence of PIM; however, there was a significantly higher incidence of PI.

PLAIN LANGUAGE SUMMARY

In this study, we investigated the condition of dental implants in 50 patients with rheumatoid arthritis (RA) compared to 51 healthy controls over 5 years. Assessments from initial treatment to the last follow-up visit included reviewing patient records and radiographs for signs of bleeding, probing depth, and bone loss. These measures helped diagnose peri-implantitis (PI) and peri-implant mucositis (PIM) based on the 2017 periodontal disease classification. The findings revealed a high implant survival rate in both groups (96%) with no significant difference in bone loss. However, the RA group showed a significantly higher incidence of PI than the healthy group that demonstrated PIM.

The clinical efficacy of powder air-polishing in the non-surgical treatment of peri-implant diseases: A systematic review and meta-analysis

Peri-implant diseases, characterized by inflammatory conditions affecting peri-implant tissues, encompass peri-implant mucositis and peri-implantitis. Peri-implant mucositis is an inflammatory lesion limited to the mucosa around an implant, while peri-implantitis extends from the mucosa to the supporting bone, causing a loss of osseointegration. For non-surgical treatments, we tested the null hypothesis that the presence or absence of air-polishing made no difference. The study focused on randomized controlled trials (RCTs) comparing air-polishing with mechanical or ultrasonic debridement, evaluating outcomes such as bleeding on probing (BOP), probing depth (PD), plaque index/plaque score (PI/PS), clinical attachment level (CAL), bone loss, and mucosal recession (MR). Two independent reviewers conducted data extraction and quality assessments, considering short-term (<6 months) and long-term (≥6 months) follow-up periods. After screening, ten articles were included in the meta-analysis. In nonsurgical peri-implant disease management, air-polishing moderately mitigated short-term PI/PS for peri-implant mucositis and showed a similar improvement in long-term BOP and bone loss for peri-implantitis compared to the control group. The Egger test found no evidence of publication bias except for the long-term PI/PS of peri-implant mucositis. Leave-one-out analysis confirmed the stability of the results. The findings highlight the need for future research with longer-term follow-up and high-quality, multi-center, large-sample RCTs.

Evaluating the microgap and sealing capability in four implant systems with different interlockings under different tightening torques: an in-vitro study

PURPOSE

This study assessed the microgap width and adhesion of three bacterial species in four dental implants with different interlocks under four screwing torques.

MATERIALS AND METHODS

Ten samples of four implant systems with various interlockings, including full-hexagonal (FHI), cylindrical-conical trilobe-index (TLI), Morse-taper with octagon terminal index (OI), and hexagonal interlock (slip-fit) (HI-SF), were used. The abutments were screwed to the fixtures under torques of 10, 20, 30, and 40 Ncm. The microgap between the abutment and the platform was assessed using a Scanning Electron Microscope (SEM). The leakage of 3 bacteria, including Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa, was evaluated under 30 Ncm torque.

RESULTS

The TLI system showed the widest gap under all torques compared to others. There was no significance among all systems under different screwing torques. Regarding the leakage, there was no adherence to E. coli and S. aureus and 36.4% of Ps. aeruginosa to the HI-SF, followed by the OI system. The FHI and TLI systems showed the highest bacterial adherence.

CONCLUSION

Even with low torque, the studied systems showed gap widths narrower than acceptable width. Implant systems with FHI and OI demonstrated misfits of less than 2 µm upon 10 Ncm and less than 1 µm when the torque increases, giving them priority to be used in areas with poor bone quality. The HI-SF demonstrated a high ability to resist the adherence to E. coli and S. aureus, followed by OI. However, Ps. aeruginosa demonstrated a high ability to adhere to all systems.

Peri-implantitis after 40 years: Evidence, mechanisms, and implications: A mapping review

STATEMENT OF PROBLEM

The high prevalence of peri-implantitis (PI) continues to plague patients and the disease is resistant to present treatment regimens. An analysis of the available research is lacking.

PURPOSE

Given the abundance and diversity of research on the topic of PI, the purpose of this mapping review was to synthesize the literature on the prevention of PI, the histopathology of the disease, the state of present therapeutics, and any emerging treatments.

MATERIAL AND METHODS

An extensive literature search was undertaken by using the electronic databases of PubMed, Web of Science, and Science Direct. The keyword strings were peri-implantitis, dental implant, risk assessment, histopathology, prosthesis design, and treatment. The filters applied were time interval from 2000 to 2002; language, English.

RESULTS

A total of 3635 articles were taken from PubMed, 3686 articles from Web of Science, and 2450 articles from Science Direct. After applying the inclusion and exclusion criteria to the titles and abstracts of selected investigations, 214 studies were retrieved.

CONCLUSIONS

The evidence reflects a concerning incidence of PI, without a predictable treatment protocol. An in-depth patient risk assessment considering risk modification, emphasis on surgical and restorative expertise, and strict recall and maintenance is essential to minimize PI.

Identification of susceptibility modules and genes for peri-implantitis compared to periodontitis within the same host environment using weighted gene co-expression network analysis

PURPOSE

This study aimed to identify new susceptibility modules and genes by analyzing the transcriptional profiles of peri-implantitis and periodontitis within the same host environment, using weighted gene co-expression network analysis (WGCNA).

METHODS

Gingival tissue samples were collected from 10 patients, each presenting with both periodontitis and peri-implantitis sites, and were used for RNA sequencing. We conducted WGCNA to identify key modules that showed distinct transcriptional expression profiles between periodontitis and peri-implantitis. Gene Ontology enrichment and Kyoto Encyclopedia of Genes and Genomes pathway analyses were carried out using R software. Genes with an adjusted P value greater than 0.05 were excluded from gene selection using the Pearson correlation method.

RESULTS

A total of 2,226 regulated genes were identified, and those with similar expression patterns were grouped into 5 color-coded functional modules using WGCNA. Among these, 3 modules showed distinct differences in expression profiles between peri-implantitis and periodontitis. The turquoise and yellow modules were associated with upregulation in peri-implantitis, while the blue module was linked to periodontitis. This finding suggests that peri-implantitis and periodontitis have significantly different transcriptional signatures. Over-representation analysis was conducted to explore the component genes of the established modules. The top-ranked genes, selected based on their network connectivity within the modules, were identified using DESeq2 and were considered hub genes.

CONCLUSIONS

WGCNA revealed distinct modular gene patterns in peri-implantitis and periodontitis, highlighting transcriptional differences between the 2 conditions. Notably, we identified 10 key genes from each of the 3 modules-the blue module associated with periodontitis-dominant pathways, and the turquoise and yellow modules associated with peri-implantitis-dominant pathways. The hub genes and pathways unveiled in this research are likely key contributors to the progression of peri-implantitis and warrant further exploration as promising candidates.

Antimicrobial adhesive self-healing hydrogels for efficient dental biofilm removal from periodontal tissue

OBJECTIVES

Oral biofilms, including pathogens such as Porphyromonas gingivalis, are involved in the initiation and progression of various periodontal diseases. However, the treatment of these diseases is hindered by the limited efficacy of many antimicrobial materials in removing biofilms under the harsh conditions of the oral cavity. Our objective is to develop a gel-type antimicrobial agent with optimal physicochemical properties, strong tissue adhesion, prolonged antimicrobial activity, and biocompatibility to serve as an adjunctive treatment for periodontal diseases.

METHODS

Phenylboronic acid-conjugated alginate (Alg-PBA) was synthesized using a carbodiimide coupling agent. Alg-PBA was then combined with tannic acid (TA) to create an Alg-PBA/TA hydrogel. The composition of the hydrogel was optimized to enhance its mechanical strength and tissue adhesiveness. Additionally, the hydrogel's self-healing ability, erosion and release profile, biocompatibility, and antimicrobial activity against P. gingivalis were thoroughly characterized.

RESULTS

The Alg-PBA/TA hydrogels, with a final concentration of 5 wt% TA, exhibited both mechanical properties comparable to conventional Minocycline gel and strong tissue adhesiveness. In contrast, the Minocycline gel demonstrated negligible tissue adhesion. The Alg-PBA/TA hydrogel also retained its rheological properties under repeated 5 kPa stress owing to its self-healing capability, whereas the Minocycline gel showed irreversible changes in rheology after just one stress cycle. Additionally, Alg-PBA/TA hydrogels displayed a sustained erosion and TA release profile with minimal impact on the surrounding pH. Additionally, the hydrogels exhibited potent antimicrobial activity against P. gingivalis, effectively eliminating its biofilm without compromising the viability of MG-63 cells.

SIGNIFICANCE

The Alg-PBA/TA hydrogel demonstrates an optimal combination of mechanical strength, self-healing ability, tissue adhesiveness, excellent biocompatibility, and sustained antimicrobial activity against P. gingivalis. These attributes make it superior to conventional Minocycline gel. Thus, the Alg-PBA/TA hydrogel is a promising antiseptic candidate for adjunctive treatment of various periodontal diseases.

Oxidative damage biomarkers and antioxidant enzymes in saliva of patients with peri-implant diseases

OBJECTIVES

8-hydroxydeoxyguanosine (8-OHdG) and Malondialdehyde (MDA) are commonly used as markers to evaluate oxidative DNA and Lipid damage in disorders including chronic inflammatory diseases. Superoxide dismutase (SOD) and glutathione peroxidase (GPx) protect tissues against oxidative injury from free oxygen radicals generated by various metabolic processes. The aim of this study was to evaluate 8-OHdG and MDA levels, and SOD and GPx activities in whole saliva of patients with peri-implant diseases.

MATERIALS AND METHODS

A cross-sectional study was conducted on a sum of 60 age gender balanced; peri-implantitis (n = 20), peri-mucositis (n = 20) and healthy (n = 20) individuals. Unstimulated whole saliva samples were collected and to determine the clinical condition of each subject; the plaque index (PI), gingival index (GI), peri-implant probing pocket depth (PIPD), peri-implant presence of bleeding on probing (BOP) (with/without suppuration) and radiographic signs of crestal bone loss (BL) were measured. The salivary 8-OHdG level was measured using the ELISA method. SOD, GPx activities and MDA levels were determined spectrophotometrically.

RESULTS

A total of 60 individuals had evaluations of 318 implants. In comparison to the peri-mucositis and peri-implantitis groups, the healthy group had significantly lower PI and GI scores (p < 0.001). The PIPD value differed amongst the groups, with the peri-implantitis group having the highest value (p < 0.001). Compared to the peri-mucositis and control groups, the peri-implantitis group had a significantly higher BL score (p < 0.001 and p < 0.001, respectively). The peri-implantitis group showed a significantly higher 8-OHdG level (p < 0.001; p < 0.001 respectively) than the peri-mucositis and control groups. Compared to the peri-mucositis and control groups, the peri-implantitis group had a significantly higher MDA level (p < 0.001 and p < 0.001, respectively). The peri-implantitis group had a significantly higher SOD level (p < 0.001 and p < 0.001, respectively) in comparison to the peri-mucositis and control groups. There was no significant difference in GPx levels between the peri-mucositis and control groups (p > 0.05), while the peri-implantitis group had significantly lower GPx levels than the peri-mucositis and control groups (p < 0.001 and p < 0.001, respectively).

CONCLUSIONS

Elevated levels of oxidative stress in saliva may indicate the onset of pathological bone loss surrounding the implant and may be an indication of peri-implantitis.

CLINICAL RELEVANCE

In peri-implant diseases, changes may occur in the levels of 8-OHdG, MDA, SOD and GPx in saliva, which may lead to a deterioration in the oxidant/antioxidant balance.

Interfacial delivery of carbon monoxide via smart titanium implant coating for enhanced soft tissue integration with switchable antibacterial and immunomodulatory properties

Soft tissue integration around titanium (Ti) implants is weaker than that around natural teeth, compromising long-term success of Ti implants. Carbon monoxide (CO) possesses distinctive therapeutic properties, rendering it as a highly promising candidate for enhancing STI. However, achieving controlled CO generation at the STI interface remains challenging. Herein, a controlled CO-releasing dual-function coating was constructed on Ti surfaces. Under near-infrared (NIR) irradiation, the designed surface could actively accelerate CO generation for antibiosis against both aerobic and anaerobic bacteria. More importantly, in the absence of NIR, the slow release of CO induces macrophage polarization from pro-inflammatory phenotype towards pro-regenerative phenotype. In a rat implantation model with induced infection, the designed surface effectively controlled the bacterial infection, alleviates accompanying inflammation and modulated immune microenvironment, leading to enhanced STI. Single-cell sequencing revealed that the coating alters the cytokine profile within the soft tissue, thereby influencing cellular functions. Differentially expressed genes in macrophages are highly enriched in the PIK3-Akt pathway. Furthermore, the cellular communication between fibroblasts and macrophages was significantly enhanced through the CXCL12/CXCL14/CXCR4 and CSF1-CSF1R ligand-receptor pair. These findings indicate that our coating showed an appealing prospect for enhancing STI around Ti implants, which would ultimately contribute to the improved long-term success of Ti implants.

Callistemon citrinus: A plant‐mediated synthesis of sustainable Rhodium nanoparticles and their antimicrobial activity

This work investigates the potential of using Callistemon citrinu flower extract, commonly known as bottlebrush, in the environmentally friendly synthesis of Rhodium nanoparticles (Rh NPs). Callistemon citrinu flower extract contains a high concentration of flavonoids and other phytochemicals. Hence, the extract was used to provide the essential components for an environmentally, sustainable synthesis method of Rh NPs. Different characterization analyses were used to evaluate the different properties of the synthesized particles. UV spectroscopy analysis demonstrated a continuous UV absorption spectrum attributed to the formation of Rh NPs. The XRD data and SAED analysis showed an amorphous nature of the synthesized Rh NPs. The HRTEM imaging provided morphological information about the Rh NPs tested sample, where the efficiency of Callistemon citrinu flower extract as a capping agent was reported. Furthermore, Raman spectra displayed the characteristic vibrational bands of the synthesized Rh NPs. The antimicrobial activity of the synthesized samples was tested against several dental pathogens, that play a role in dental caries, Staphylococcus aureus (SA), Bacillus subtilis (BS), Candida albicans (CA), Escherichia coli (Eco), and Staphylococcus epidermidis (S. Epi). In comparison with the control, Chlorhexidine (CHX), Rh NPs showed a greater impact on C. albicans (20 ≤ Zone of inhibition (ZOI) (mm) ≤ 26). The statistical analysis demonstrated that Rh NPs had a greater mean ZOI than the Callistemon citrinu flower extract. These results reveal the considerable potential and biological capacity Rh NPs have as an antifungal agent for dental applications.

Levels of matrix metalloproteinase-1 (MMP-1), MMP-2, MMP-3, osteopontin, pentraxin-3, and thymic stromal lymphopoietin in crevicular fluid samples from peri-implantitis, periodontitis, and healthy sites

AIM

Periodontitis and peri-implantitis are chronic inflammatory diseases characterized by the destruction of supporting tissues. Despite some similarities, it is essential to understand the differences in how these diseases elicit unique host responses within the oral tissues, including the production of selected matrix metalloproteinases (MMPs) and inflammatory mediators involved in tissue remodelling. The aim of this study was to evaluate the levels of proteolytic enzymes MMP-1, MMP-2, MMP-3, as well as the inflammatory mediators osteopontin (OPN), pentraxin-3 (PTX3), and thymic stromal lymphopoietin (TSLP) in crevicular fluid samples collected from healthy, periodontitis-affected, and peri-implantitis sites.

METHODS

Gingival crevicular fluid (GCF) and peri-implant crevicular fluid (PICF) samples were collected from healthy and diseased teeth and implant sites of 163 patients. The MMP-1, MMP-2, MMP-3, OPN, PTX3, and TSLP levels were determined using commercially available immunoassays. A linear mixed model procedure was adopted for multilevel analyses, using biomarker levels as the outcome variable to compare two types of sites. The diagnostic accuracy of the biomarkers was evaluated by Youden's index to estimate the sensitivity, specificity and the area under curve (AUC).

RESULTS

The levels of MMP-1, MMP-2, MMP-3, OPN, and TSLP were higher at sites with periodontitis and peri-implantitis compared to the levels at sites with healthy teeth and healthy implants. No significant differences were observed in the levels of the measured markers between the sites diagnosed with periodontitis and those diagnosed with peri-implantitis. The highest diagnostic potential at implant sites was found for MMP-2 (AUC = 0.74) and TSLP (AUC = 0.72). The highest AUC (0.82) at tooth sites was found for OPN.

CONCLUSIONS

The findings indicate that the proteolytic enzyme MMP-2 and the cytokine TSLP might be potential biomarkers for both periodontitis and peri-implantitis, whereas the proinflammatory cytokine OPN may serve as a biomarker for periodontitis. Further studies are required to confirm the utility of these biomarkers and explore their potential clinical applications.

Effect of Silicon Nitride Coating on Titanium Surface: Biocompatibility and Antibacterial Properties

In recent years, with the advent of a super-aged society, lifelong dental care has gained increasing emphasis, and implant therapy for patients with an edentulous jaw has become a significant option. However, for implant therapy to be suitable for elderly patients with reduced regenerative and immunological capabilities, higher osteoconductive and antimicrobial properties are required on the implant surfaces. Silicon nitride, a non-oxide ceramic known for its excellent mechanical properties and biocompatibility, has demonstrated high potential for inducing hard tissue differentiation and exhibiting antibacterial properties. In this study, silicon nitride was deposited on pure titanium metal surfaces and evaluated for its biocompatibility and antibacterial properties. The findings indicate that silicon nitride improves the hydrophilicity of the material surface, enhancing the initial adhesion of rat bone marrow cells and promoting hard tissue differentiation. Additionally, the antibacterial properties were assessed using Staphylococcus aureus, revealing that the silicon nitride-coated surfaces exhibited significant antibacterial activity. Importantly, no cytotoxicity was observed, suggesting that silicon nitride-coated titanium could serve as a novel implant material.

Expression of miRNAs (146a and 155) in human peri-implant tissue affected by peri-implantitis: a case control study

BACKGROUND

In literature, the levels of miRNA-146a and miRNA-155 are increased in periodontitis. Limited data are available regarding the expression of miRNA-146a and miR-NA-155 in diseased human peri-implant tissue. Therefore, the objective of this study was to explore the expression of miRNA-146a and miRNA-155 in human gingival peri-implant tissue affected by peri-implantitis.

METHODS

After recording the clinical parameters, human peri-implant pocket tissues were harvested from sites diagnosed with peri-implantitis (n = 15 cases) in addition to healthy peri-implant sulcus tissues (n = 15 controls). The levels of miRNA-146a and miRNA-155 were assessed using real-time qPCR.

RESULTS

Cases exhibited a significantly higher mean expression of miRNA-155 (5.2-fold increase) and miRNA-146a (2.8-fold increase) than controls. MiRNA-155 and miRNA-146a demonstrated an appropriate sensitivity (87.5% and 87.5%, respectively) and specificity (73.3% and 66.7%, respectively) in discriminating cases from controls. A moderate correlation (r = 0.544, p = 0.029) was found between miRNA-155 and miRNA-146a levels in the case group.

CONCLUSIONS

The expressions of miRNA-146a and miR-NA-155 are different between healthy and peri-implantitis affected tissues. Both miRNAs might potentially able to discriminate healthy from peri-implantitis affected tissues.

A Biomimetic Multifunctional Scaffold for Infectious Vertical Bone Augmentation

The regenerative treatment of infectious vertical bone defects remains difficult and challenging today. Current clinical treatments are limited in their ability to control bacteria and infection, which is unfavorable for new bone formation and calls for a new type of material with excellent osteogenic and antibacterial properties. Here a multifunctional scaffold is synthesized that mimics natural bone nanostructures by incorporating silver nanowires into a hierarchical, intrafibrillar mineralized collagen matrix (IMC/AgNWs), to achieve the therapeutic goals of inhibiting bacterial activity and promoting infectious alveolar bone augmentation in rats and beagle dogs. An appropriate concentration of 0.5 mg mL-1 AgNWs is selected to balance biocompatibility and antibacterial properties. The achieved IMC/AgNWs exhibit a broad spectrum of antimicrobial properties against Gram-negative Porphyromonas gingivalis and Gram-positive Streptococcus mutans. When the IMC/AgNWs are cocultured with periodontal ligament stem cells, it possesses excellent osteoinductive activities under both non-inflammatory and inflammatory conditions. By constructing a rat mandibular infected periodontal defect model, the IMC/AgNWs achieve a near-complete healing through the canonical BMP/Smad signaling. Moreover, the IMC/AgNWs enhance vertical bone height and osseointegration in peri-implantitis in beagle dogs, indicating the clinical translational potential of IMC/AgNWs for infectious vertical bone augmentation.

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.

Comparative Study of Callistemon citrinus (Bottlebrush) and Punica granatum (Pomegranate) Extracts for Sustainable Synthesis of Silver Nanoparticles and Their Oral Antimicrobial Efficacy

A comparative study was applied to investigate the potential of Callistemon citrinus (bottlebrush) flower extract (BBE) and Punica granatum (pomegranate) peel extracts (PPE) for the sustainable synthesis of the silver nanoparticles, Ag-BBE and Ag-PPE, respectively. The synthesis process of Ag NPs using the selected extracts was applied under optimized conditions. Hence, the effect of the selected plant's type on the different characteristics of the synthesized green Ag NPs was investigated. The UV-Vis spectroscopy revealed the presence of the characteristic silver peaks at 419 and 433 nm of the Ag-BBE and Ag-PPE, respectively. The XRD spectra reported the fcc phase formation of Ag NPs. The TEM results highlighted the morphological features of the synthesized Ag NPs. with a size range of 20-70 nm, and with 10-30 nm for Ag-BBE and Ag-PPE, correspondingly. The Raman spectra revealed characteristic silver bands in the Ag-PPE and reflected some bands related to the natural extract in the Ag-BBE sample. The antimicrobial activity and statistical analysis investigation were conducted against four selected oral pathogens (Staphylococcus aureus (SA), Candida albicans (CA), Staphylococcus epidermidis (S. epi), and Enterococcus faecalis (EF)). Both tested extracts, BBE, and PPE, revealed potential effectivity as reducing and capping agents for Ag NP green synthesis. However, the synthesized NPs demonstrated different features, depending on the used extract, reflecting the influence of the plant's biomolecules on the nanoparticles' properties.

Bioinformatics investigation of adaptive immune-related genes in peri-implantitis and periodontitis: Characteristics and diagnostic values

BACKGROUND

Peri-implantitis and periodontitis have similar immunological bioprocesses and inflammatory phenotypes. In the inflammatory process, the adaptive immune cells can drive the development of disease. This research investigated the differences and diagnostic significance of peri-implantitis and periodontitis in adaptive immune responses.

METHODS

We acquired four GEO datasets of gene expressions in surrounding tissues in healthy person, healthy implant, periodontitis, and peri-implantitis patients. The structural characteristics and enrichment analyses of differential expression genes were examined. The adaptive immune landscapes in peri-implantitis and periodontitis were then evaluated using single sample gene set enrichment analysis. The STRING database and Cytoscape were used to identify adaptive hub genes, and the ROC curve was used to verify them. Finally, qRT-PCR method was used to verify the expression level of Hub gene in activated T cells on the titanium-containing or titanium-free culture plates.

RESULTS

At the transcriptome level, the data of healthy implant, peri-implantitis and periodontitis were highly dissimilar. The peri-implantitis and periodontitis both exhibited adaptive immune response. Except for the activated CD4+T cells, there was no significant difference in other adaptive immune cells between peri-implantitis and periodontitis. In addition, correlation analysis showed that CD53, CYBB, and PLEK were significantly positively linked with activated CD4+T cells in the immune microenvironment of peri-implantitis, making them effective biomarkers to differentiate it from periodontitis.

CONCLUSIONS

Peri-implantitis has a uniquely immunogenomic landscape that differs from periodontitis. This study provides new insights and ideas into the activated CD4+T cells and hub genes that underpin the immunological bioprocess of peri-implantitis.

Peri-implant mucositis and peri-implantitis: key features and differences

Peri-implant diseases are frequent complications that occur around osseointegrated endosseous implants and are the result of an imbalance between the bacterial challenge and host response. Peri-implant diseases may affect the peri-implant mucosa only (peri-implant mucositis) or also involve the supporting bone (peri-implantitis). Early detection of peri-implant diseases and timely treatment is important for the success of dental implant treatment. Peri-implant probing is essential to assess the peri-implant health status and should be done at each recall visit. Dental practitioners should be familiar with the clinical and radiological features of both conditions in order to make an accurate diagnosis and determine the appropriate treatment required. This article aims to provide clinicians with an understanding of the key differences between peri-implant health, peri-implant mucositis and peri-implantitis.

Evaluation of salivary stress markers and inflammatory cytokine levels in peri-implantitis patients

BACKGROUND AND OBJECTIVE

Psychological stress has been identified in some observational studies as a potential factor that may modify and affect periodontal diseases, but there are no similar data for peri-implantitis. The aim of this study was to determine the relationship between interleukin (IL)-1β, IL-6, IL-10, interferon (IFN)α inflammatory cytokines and the psychological stress-related markers, glucocorticoid receptor-α (GRα), and salivary α-amylase (sAA) gene expression levels in saliva samples obtained from healthy implants and peri-implantitis patients.

MATERIALS AND METHODS

The study included a total of 50 systemically healthy subjects. Peri-implant clinical parameters were recorded and psychological stress level was evaluated with the hospital anxiety and depression scale (HAD) and state-trait anxiety inventory (STAI) questionnaire forms. Following the evaluations, the patients were divided into 4 groups according their stress and clinical status (Ia, Ib, IIa, IIb). IL-1β, IL-6, IL-10, IFNα, GRα, sAA gene expression levels in the saliva samples were quantified by quantitative polymerase chain reaction (qPCR).

RESULTS

In the group of peri-implantitis who had a high score in stress level assessment scales, significantly higher IL-1β, IL-6, sAA expression levels were observed (p < 0.001). The IL-10 gene expression levels were lower in the groups with a high score in the stress level assessment scales (p < 0.001). GRα gene was expressed at lower levels in the group of peri-implantitis who had a high score in stress level assessment scales but the difference was not statistically significant (p = 0.065).

CONCLUSION

The study findings suggest that psychological stress may increase the inflammation associated with peri-implantitis by affecting cytokine expression levels.

CLINICAL RELEVANCE

To prevent peri-implantitis or reduce its prevalence, it could be beneficial to evaluate stress levels and identify individuals experiencing stress.

Quantity and Size of Titanium Particles Released from Different Mechanical Decontamination Procedures on Titanium Discs: An In Vitro Study

Complications such as peri-implantitis could ultimately affect the survival of a dental implant. The prevention and treatment of peri-implant diseases require managing bacterial biofilm and controlling environmental risks, including the presence of pro-inflammatory titanium (Ti) particles in the peri-implant niche. Objectives included the evaluation of the size and quantity of Ti particles released from moderately roughened Ti surfaces during common mechanical surface decontamination methods. One hundred and forty moderately roughened Ti discs were divided into seven groups (n = 20 per group); six groups received mechanical decontamination procedures (ultrasonic scaling (US) with a metal tip and poly-ether-ketone (PEEK) under low and medium power settings, air-polishing with erythritol powder, and Ti brush), and the control group underwent air-water spray using a dental triplex. The rinsing solution was collected for Ti mass analysis using inductively coupled plasma mass spectrometry (ICPMS), as well as for Ti particle size and count analysis under scanning electron microscopy (SEM) with energy-dispersive spectroscopy (EDS). US metal tip instrumentation generated 34.00 ± 12.54 μg and 34.44 ± 6.08 μg of Ti under low and medium power settings, respectively. This amount of Ti generation was significantly higher than other instrumentation methods. The mean Ti particle size of the US groups ranged from 0.89 ± 0.27 μm to 1.25 ± 0.24 μm. No statistically significant difference was found in the particle size among US groups and Ti brush group (1.05 ± 0.11 μm), except for US with the PEEK tip, where a significantly smaller mean particle diameter was found at the low power setting (0.89 ± 0.27 μm). Mechanical instrumentation can produce Ti particulates and modify the implant surfaces. US using a metal tip generated the highest amount of Ti with smaller Ti size particles compared to all other commonly used mechanical surface instrumentations. The EDS analysis confirmed Ti in PEEK US tips. It can be suggested that deterioration from the PEEK US tip and Ti brush, as observed under SEM, is an additional source of Ti release during Ti surface decontamination.

Effect of preoperative chlorhexidine, essential oil, and cetylpyridinium chloride mouthwashes on bacterial contamination during dental implant surgery: A randomized controlled clinical trial

Background

Although the role of chlorhexidine and other mouthwashes in periodontal therapy has been elucidated, little information is available on their use as routine preoperative mouth rinses before surgery, especially in periodontal procedures such as dental implant surgery.

Objective

This study aimed to compare the efficacy of preoperative chlorhexidine, essential oil, and cetylpyridinium chloride mouthwashes in reducing bacterial contamination at the time of implant placement.

Materials and Methods

Eligible patients who underwent dental implant surgery were randomly divided into four groups based on the mouthwash used: (1) 0.12 % chlorhexidine, (2) essential oil, (3) cetylpyridinium chloride, and (4) saline (served as the control group). All the patients of each group rinsed preoperatively with 15 mL of the respective mouthwash for 60 s. Saliva samples before (pre) and immediately after rinsing with the mouthwash (post) and after suturing the flap (end) were collected on the day of the implant placement. Real-time quantitative polymerase chain reaction (qPCR) was performed to analyze the samples and quantify the targeted periodontal pathogens using a propidium monoazide (PMA) dye.

Results

Forty patients were included in the study. Real-time qPCR demonstrated a significant reduction in the number of pathogens in the saliva samples of the mouthwash groups compared to that of the control group. A statistically significant difference was observed between the groups for the pre-post and pre-end samples (p < 0.001) but not for the post-end samples (p = 0.203). A statistically significant difference was observed between the chlorhexidine, essential oil, and cetylpyridinium chloride mouthwash groups and the saline group (P < 0.001). The bacterial counts significantly differed with and without the use of the PMA dye.

Conclusions

Preoperative chlorhexidine, essential oil, and cetylpyridinium chloride mouthwashes can reduce the bacterial load at the time of implant placement, thereby reducing the incidence of implant-related complications.

New insights on collagen structural organization and spatial distribution around dental implants: a comparison between machined and laser-treated surfaces

BACKGROUND

One of the main factors for the osseointegration of dental implants is the development of an adequate soft tissue barrier, mainly composed by collagen, which protects the implant from bacterial development. The structural features of the peri-implant collagen are influenced by the implant components and, in particular, by the type of the surface. In the clinical practice, healing abutments are characterized by smooth surfaces, named machined. Recently, a new laser technique, Synthegra, has been developed to obtain a topography-controlled surface with micrometric regular pores that seems reducing the risk of peri-implantitis. Based on this background, this study aims investigating the structural organization and spatial distribution of collagen surrounding healing abutments characterized by laser-treated and machined surfaces.

METHODS

Gingiva portions surrounding custom-made healing abutments (HA), characterized by alternated laser-treated and machined surfaces, were collected and analyzed by combining Fourier Transform InfraRed Imaging (FTIRI) spectroscopy, a non-invasive and high-resolution bidimensional analytical technique, with histological and multivariate analyses.

RESULTS

Masson's trichrome staining, specific for collagen, highlighted a massive presence of collagen in all the analyzed samples, evidencing a surface-related spatial distribution. The nature of collagen, investigated by the FTIRI spectroscopy, appeared more abundant close to the laser-treated surface, with a perpendicular disposition of the bundles respect to the HA; conversely, a parallel distribution was observed around the machined surface. A different secondary structure was also found, with a higher amount of triple helices and a lower quantity of random coils in collagen close to the laser treated surfaces.

CONCLUSIONS

FTIRI spectroscopy demonstrates that the use of a laser treated transmucosal surface can improve the morphological organization of the peri-implant collagen, which presents a distribution more similar to that of natural teeth.

TRIAL REGISTRATION

This trial is registered with ClinicalTrials.gov Identifier: (Registration Number: NCT05754970). Registered 06/03/2023, retrospectively registered, https://clinicaltrials.gov/show/NCT05754970 .

Reprogramming mitochondrial metabolism of macrophages by miRNA-released microporous coatings to prevent peri-implantitis

Although various new biomaterials have enriched the methods for peri-implant inflammation treatment, their efficacy is still debated, and secondary operations on the implant area have also caused pain for patients. Recently, strategies that regulate macrophage polarization to prevent or even treat peri-implantitis have attracted increasing attention. Here, we prepared a laser-drilled and covered with metal organic framework-miR-27a agomir nanomembrane (L-MOF-agomir) implant, which could load and sustain the release of miR-27a agomir. In vitro, the L-MOF-agomir titanium plate promoted the repolarization of LPS-stimulated macrophages from M1 to M2, and the macrophage culture supernatant promoted BMSCs osteogenesis. In a ligation-induced rat peri-implantitis model, the L-MOF-agomir implants featured strong immunomodulatory activity of macrophage polarization and alleviated ligation-induced bone resorption. The mechanism of repolarization function may be that the L-MOF-agomir implants promote the macrophage mitochondrial function and metabolism reprogramming from glycolysis to oxidative phosphorylation. Our study demonstrates the feasibility of targeting cell metabolism to regulate macrophage immunity for peri-implantitis inhibition and provides a new perspective for the development of novel multifunctional implants.

A retrospective study of the long-term survival of RESTORE® dental implants with resorbable blast media surface

PURPOSE

The aim of this study was to retrospectively evaluate the survival and failure rates of RESTORE® implants over a follow-up period of 10-15 years at a university dental hospital and to investigate the factors affecting the survival rate of these dental implants.

METHODS

A total of 247 RESTORE® dental implants with a resorbable blast media (RBM) surface inserted in 86 patients between March 2006 and April 2011 at the Department of Periodontology of Seoul National University Dental Hospital were included. Patients with follow-up periods of less than 10 years were excluded, and data analysis was conducted based on dental records and radiographs.

RESULTS

Over a 10- to 15-year period, the cumulative survival rate of the implants was 92.5%. Seventeen implants (6.88%) were explanted due to implant fracture (n=10, 4.05%), peri-implantitis (n=6, 2.43%), and screw fracture (n=1, 0.4%). The results of univariate regression analysis using a Cox proportional hazards model demonstrated that implants placed in male patients (hazard ratio [HR], 4.542; 95% confidence interval [CI], 1.305-15.807; P=0.017) and implants that supported removable prostheses (HR, 15.498; 95% CI, 3.105-77.357; P=0.001) showed statistically significant associations with implant failure.

CONCLUSIONS

Within the limitations of this retrospective study, the RESTORE® dental implant with an RBM surface has a favorable survival rate with stable clinical outcomes.

Dental implant material related changes in molecular signatures in peri-implantitis - A systematic review of omics in-vivo studies

OBJECTIVE

Titanium particles have been shown in in-vitro studies to lead to the activation of specific pathways, this work aims to systematically review in- vivo studies examining peri-implant and periodontal tissues at the transcriptome, proteome, epigenome and genome level to reveal implant material-related processes favoring peri-implantitis development investigated in animal and human trials.

METHODS

Inquiring three literature databases (Medline, Embase, Cochrane) a systematic search based on a priori defined PICOs was conducted: '-omics' studies comparing molecular signatures in healthy and infected peri-implant sites and/or healthy and periodontitis-affected teeth in animals/humans. After risk of bias assessments, lists of differentially expressed genes and results of functional enrichment analyses were compiled whenever possible.

RESULTS

Out of 2187 screened articles 9 publications were deemed eligible. Both healthy and inflamed peri-implant tissues showed distinct gene expression patterns compared to healthy/diseased periodontal tissues in animal (n = 4) or human studies (n = 5), with immune response, bone metabolism and oxidative stress being affected the most. Due to the lack of available re-analyzable data and inconsistency in methodology of the eligible studies, integrative analyses on differential gene expression were not applicable CONCLUSION: The differences of transcriptomic signatures in between peri-implant lesions compared to periodontal tissue might be related to titanium particles arising from dental implants and are in line with the in-vitro data recently published by our group. Nevertheless, limitations emerge from small sample sizes of included studies and insufficient publication of re-analyzable data.

Effect of periostin in peri-implant sulcular fluid and gingival crevicular fluid: A comparative study

Background

Various similarities have been observed between gingival crevicular fluid (GCF) and peri-implant sulcular fluid (PISF). This has resulted in research that has evaluated similar biological fluid markers that are similar to those present within the gingival sulcus. These biomarkers have high sensitivity and are a reliable biological tool when compared to clinical and/or radiographic examination and aid in diagnosis as well as monitoring the progression of periodontal disease surrounding teeth as well as the implants.

Aim

The study aimed to compare the effectiveness of periostin in peri-implant sulcular and gingival crevicular fluids.

Materials and Methods

This experimental prospective in vitro analysis was done following clearance by the institutional ethical committee. A total of 100 patients were selected. They were categorized into two groups: (I) Group A patients had peri-implant disease (n = 50), whereas (II) Group B patients had periodontitis (n = 50). Clinical loss of attachment score was noted in six sites around natural teeth and four sites around the implants. Presterilized filter paper strips were inserted within the sulcus/pocket till pressure was felt for 60 s. Periostin concentration levels in GCF and PISF samples were measured by the enzyme-linked immunosorbent assay technique. Statistical analysis of data collected was performed using Shapiro-Wilk statistical tool for normally distributed numerical data.

. Results

Mean ± standard deviation concentration of periostin in gingival crevicular fluid from periodontitis cases was recorded as 20.15 ± 2.76 ng/30sn, whereas in PISF was 19.23 ± 1.89 ng/30sn. On statistical analysis, no statistically significant differences were seen after comparing the concentration of periostin in periodontitis as well as peri-implantitis groups (P > 0.05).

Conclusion

The present study analyzed periostin levels in gingival crevicular fluid obtained from patients diagnosed with periodontitis and sulcular fluid obtained from the sulcus around implants. Early biological markers or indicators of inflammation should be studied to determine the prognosis of treatment apart from the clinical assessment for the patient's benefit.

A novel nonsurgical therapy for peri-implantitis using focused pulsed electromagnetic field: A pilot randomized double-blind controlled clinical trial

Pulsed electromagnetic field (PEMF) therapy modulates the immune response and is successfully used in orthopedics to treat osteoarthritis and improve bone regeneration. This may suggest that this treatment may consequently reduce peri-implant soft tissue inflammation and marginal bone loss. To compare clinical, radiographic, and immunological results following nonsurgical treatment for peri-implantitis with or without PEMF therapy. Patients with peri-implantitis were included: pocket probing depth (PPD) between 6 and 8 mm with bleeding on probing (BOP); crestal bone loss between 3 and 5 mm. A novel healing abutment that contained active (test) or inactive (control) PEMF was connected. PEMF was administered via the abutment at exposure ratio of 1/500-1/5000, intensity: 0.05-0.5 mT, frequency: 10-50 kHz for 30 days. Nonsurgical mechanical implant surface debridement was performed. Patients were examined at baseline, 1 and 3 months. Clinical assessment included: plaque index, BOP, PPD, recession, and bone crest level which was radiography measured. Samples of peri-implant crevicular fluid were taken to analyze interleukin-1β (IL-1β). Twenty-three patients (34 implants; 19 control, 15 test) were included. At the follow-up, mean crestal bone loss was lower in the test group at 1 and 3 months (2.48 mm vs. 3.73 mm, p < 0.05 and 2.39 vs. 3.37, p < 0.01). IL-1β levels were also lower in the test group at 2 weeks (72.86 pg/mL vs. 111.7, p < 0.05). Within all the limitation of this preliminary study, the test group improved clinical parameters after a short-term period compared to the control group.

Effectiveness of two photosensitizer-mediated photodynamic therapy for treating moderate peri-implant infections in type-II diabetes mellitus patients: A randomized clinical trial

PURPOSE

This study evaluated the impact of Fox Green (FG) against methylthioninium chloride (MTC)-facilitated photodynamic therapy (PDT) as an adjunctive to manual scaling (MS) on the peri‑implant clinical and cytokine parameters in type-2 diabetes mellitus (DM) patients with peri‑implantitis.

METHODS

Patients were divided into group-A comprising 13 patients who received adjunctive FG-PDT using a diode laser (wavelength: 810 nm; irradiation power: 300 mW; irradiation time: 30 s; fluence: 56 Jcm-2), group-B comprising 12 patients who received adjunctive MTC-PDT using a diode laser (wavelength: 660 nm; irradiation power: 100 mW; irradiation time: 120 s/site; fluence: 30 Jcm-2), and group-C comprising 13 patients who received MS alone [control group]). After diagnosing the diabetics with peri‑implantitis (established on eligibility criteria), a structured questionnaire was used to gather the information of the participants. Plaque (PS) and bleeding scores (BS), along with peri‑implant probing scores (PPS) and peri‑implant bone loss (PIBL), together with immunological variables (interleukin [IL]-6, tumor necrosis factor-alpha [TNF-α], and advanced glycation end products [AGEs]) were measured in all study group participants at baseline, 3-month, and 6-month follow-ups.

RESULTS

A significant reduction was observed for PS, BS, and PPS within all tested groups at each follow-up visits compared from their baseline values (p<0.05). However, a substantial decrease in PIBL was observed in all study group patients at 6-month follow-up as compared to 3-month follow-up (p<0.05). Regarding the levels of IL-6 and TNF-α, a substantial reduction was observed in all study groups until 6-month from their baseline scores (p<0.05). However, no changes were observed in the levels of AGEs in any group at either visit (p>0.05).

CONCLUSION

In DM patients with periimplantitis, adjunctive FG-PDT and MTC-PDT exhibited comparable outcomes in terms of peri‑implant clinical as well as pro-inflammatory characteristics than MS alone among peri‑implantitis patients with DM.

Clinical, microbiological and osteoimmunological findings in different peri-implant conditions - A cross-sectional study

OBJECTIVES

The aim of this study was to assess the prevalence of certain microbiota and their potential correlation with clinical parameters, expression of proinflammatory cytokines, Notch signalling pathway molecules and bone remodelling mediators among different peri-implant conditions.

MATERIALS AND METHODS

Included participants had at least one dental implant minimally 1 year in function. They were divided into peri-implantitis (PI), peri-implant mucositis (PM) and healthy implants (HIs) groups. Prevalence of P. ginigvalis, Fusobacterium spp., EBV and C. albicans was detected in participants' crevicular fluid (CF) using quantitative real-time polymerase chain reaction, different markers' expression, as well as clinical data, were correlated with the microbial presence.

RESULTS

CF samples taken from one chosen implant from each of the 102 participants were analyzed. Significantly higher levels of P. gingivalis were found in PI compared with HI (p = .012) and PM (p = .026). Fusobacterium spp. was also more prevalent in PI (p = .041) and PM (0.008) than in HI. P. gingivalis was a predictor of PPDi (p = .011, R2  = 0.063) and CALi (p = .049, R2  = 0.038). A positive correlation was found in PI for the level of Fusobacterium spp. and TNFα expression (ρ = 0.419, p = .017) while in PM, P. gingivalis and Notch 2 expression were correlated (ρ = 0.316, p = .047).

CONCLUSIONS

P. gingivalis appears to be involved in the osteolysis in patients with PI, while the positive correlation of its level with Notch 2 expression in patients with PM suggests a potential involvement of P. gingivalis in the progression of PM into PI.

The efficacy of different implant surface decontamination methods using spectrophotometric analysis: an in vitro study

PURPOSE

Various methods have been proposed to achieve the nearly complete decontamination of the surface of implants affected by peri-implantitis. We investigated the in vitro debridement efficiency of multiple decontamination methods (Gracey curettes [GC], glycine air-polishing [G-Air], erythritol air-polishing [E-Air] and titanium brushes [TiB]) using a novel spectrophotometric ink-model in 3 different bone defect settings (30°, 60°, and 90°).

METHODS

Forty-five dental implants were stained with indelible ink and mounted in resin models, which simulated standardised peri-implantitis defects with different bone defect angulations (30°, 60°, and 90°). After each run of instrumentation, the implants were removed from the resin model, and the ink was dissolved in ethanol (97%). A spectrophotometric analysis was performed to detect colour remnants in order to measure the cumulative uncleaned surface area of the implants. Scanning electron microscopy images were taken to assess micromorphological surface changes.

RESULTS

Generally, the 60° bone defects were the easiest to debride, and the 30° defects were the most difficult (ink absorption peak: 0.26±0.04 for 60° defects; 0.32±0.06 for 30° defects; 0.27±0.04 for 90° defects). The most effective debridement method was TiB, independently of the bone defect type (TiB vs. GC: P<0.0001; TiB vs. G-Air: P=0.0017; TiB vs. GE-Air: P=0.0007). GE-Air appeared to be the least efficient method for biofilm debridement.

CONCLUSIONS

T-brushes seem to be a promising decontamination method compared to the other techniques, whereas G-Air was less aggressive on the implant surface. The use of a spectrophotometric model was shown to be a novel but promising assessment method for in vitro ink studies.

Optimized titanium dioxide nanotubes for dental implants: Estimation of mechanical properties and effects on the biological behaviors of human gingival fibroblasts and oral bacteria

The long-term successes of implant restorations rely on both appropriate osseointegration and robust soft tissue integration (STI). Numerous studies have reported that titanium dioxide nanotube (TNT) arrays formed by electrochemical anodization (EA) can promote early osteogenesis, but the mechanical stability of such modifications is often ignored and remains underexplored. In addition, relatively little research has been done on their effects on soft tissues integration. In this study, we developed mechanically robust TNT arrays using an optimized EA system. Subsequently, we immobilized a peptide, specifically D-amino K122-4, onto the anodized TNTs via polydopamine (PDA) films to enhance their mechanical properties. Surface morphology and composition were characterized by scanning electron microscopy (SEM), atomic force microscopy, and X-ray photoelectron spectroscopy. Mechanical properties, including the elastic modulus and hardness of TNTs modified Ti surfaces, were assessed using the nano-indention test. The adhesive strength of TNTs films to the substrate was measured using the nano scratch test. Furthermore, we evaluated the adhesion, spreading, and proliferation of human gingival fibroblasts (HGFs) and periodontal pathogenic bacteria such as Streptococcus mutans (S.m) and F. nucleatum (F.n) on the surface. Results showed that the elastic modulus, hardness, and adhesive strength of anodized TNTs were significantly enhanced by the incorporation of the D-amino K122-4 peptide. Live-dead staining and SEM observation suggested a decreased surface colonization by both bacterial species. The antibacterial rate of S.m and F. n was 81.5% and 71.7%, respectively, evaluated by colony counting method. Additionally, results of CCK8 assay showed that modified TNTs slightly stimulated HGFs attachment and proliferation while producing enhanced fluorescence of integrin β1 and F-actin, confirmed by laser confocal microscopy observation. Thus, D-amino K122-4 biofunctionalized TNTs present significantly improved mechanical properties, and the mechanically robust structures modulate HGFs proliferation and alignment, resulting in decreased bacteria growth. This novel strategy has the potential to create a surface coating for implants that exhibits superior mechanical robustness and enhanced surface-to-implant interactions.

Dental Restorations

Fulfilling a patient's request for a healthy, functional and esthetic smile represents a daily challenge for dental practitioners [...].

Insight Into the Laboratory Diagnosis of Periimplantitis Using Reactive Oxygen Metabolite Levels - A Biochemical Study

Aim The study aims to substantiate the quantitative role of the predominant periodontopathogen (Porphyromonas gingivalis) associated with peri-implantitis and evaluate the reactive oxygen metabolite levels in peri-implantitis patients. Methodology A total of 40 participants were taken from the department of periodontology, Thai Moogambigai Dental College and Hospital, Chennai, and divided into groups I (control) and II (test). Group I included 20 participants with healthy peri-implant tissue, and group II included 20 participants with infected peri-implant tissues. The predominant periodontopathogen was detected by using a quantitative real-time polymerase chain reaction. Samples (gingival crevicular fluid (GCF), saliva, and plasma) were collected, and a biochemical assay was conducted for reactive oxygen metabolites (ROM) analysis in healthy implants (control group) and peri-implantitis conditions (test group). ROM levels of the patients were statistically analyzed. Results The qualitative and quantitative profiles of Porphyromonas gingivalis (P. gingivalis) associated with Peri-implantitis were analyzed, and the levels of ROM in periimplantitis patients were assessed. The study results substantiate the quantitative picture of Porphyromonas gingivalis in the detection of periimplantitis. The saliva and GCF samples showed significant differences in ROM levels between the test and control groups. Conclusion This is one of the few studies to detect the predominant bacterial pathogen associated with peri-implantitis and assess the ROM levels in periimplantitis patients. The study gives a correlation between the periopathogens and ROM levels, thereby facilitating the attainment of the best possible treatment options.

Association of Patient Anthropometric Measurements and Dental Implant Treatment

Background

Dental implants are currently one of the most preferred treatment modalities for replacing missing teeth, as they are the most comparable to natural teeth. Even so, satisfaction with such treatment may differ depending on patient nature. The aim of this article was to examine the relationships between different anthropometric measurements on dental implant patient's satisfaction.

Methods and Material

Self-administered questionnaire (structured questions) were given to patients who had dental implant treatment to evaluate their satisfaction level with dental-implant treatment. Different anthropometric measurements were taken: body height; weight; body mass index (BMI); body composition; waist/hip ratio; and circumferences at the waist, hip, and neck.

Results

The overall BMI was 28.9±4.7 kg/m², there was a highly-significant difference in patient satisfaction among the different BMI groups (P< 0.000). The significant difference in most of those groups was between the obese group and the other groups. For neck circumference and waist/hip ratio, a significance difference between the normal weight and obese groups (P< 0.000) was found, while for percentage of muscle, the differences were between the overweight and obese groups (P< 0.000). According to BMI groups a highly significant difference in many patient satisfaction domains were found (P< 0.000). These significant differences were between the obese group and non-obese groups for most aspects of patient satisfaction. For patient satisfaction with final appearance, the normal BMI group differed significantly from the overweight BMI group (P=0.013). Additionally, for patient satisfaction with dentist performance and communication, the overweight BMI group showed significantly higher satisfaction than the normal BMI group (P=0.019). Body measurements were correlated negatively with overall patient satisfaction, and positively with satisfaction with prosthesis.

Conclusion

The obese group patients had the lowest rate of patient satisfaction. BMI and other body measurements can be used to predict patient satisfaction with the outcome of dental implant treatment.

Non-Surgical Therapy and Oral Microbiota Features in Peri-Implant Complications: A Brief Narrative Review

The therapeutic discretion in cases of peri-implantitis should take into account the limits and advantages of specific therapeutic itineraries tailored according to each clinical case and each individual patient. This type of oral pathology emphasizes the complex classification and diagnostic issues coupled with the need for targeted treatments, in light of the oral peri-implant microbiota changes. This review highlights the current indications for the non-surgical treatment of peri-implantitis, describing the specific therapeutic efficacy of different approaches and discussing the more appropriate application of single non-invasive therapies The non-surgical treatment choice with antiseptics or antibiotics (single or combined, local, or systemic) for short courses should be considered on a case-by-case basis to minimize the incidence of side effects and concomitantly avoid disease progression.

Peri-implant crevicular fluid and serum levels of soluble ST2 in peri-implant diseases: A pilot study

BACKGROUND AND OBJECTIVE

Soluble ST2 (sST2) is a current biomarker of cardiovascular disease. It is used to predict susceptibility to cardiovascular diseases and to analyze their prognosis. Serum sST2 level increases in inflammatory diseases such as periodontitis. However, the level of sST2 in peri-implant diseases and crevicular fluid has not been investigated yet. Thus, the aim of this cross-sectional study is to analyze the level of sST2 in peri-implant health and diseases.

METHODS

Sixty-nine participants were divided into 3 groups as peri-implant health (PH), peri-implant mucositis (PM), and peri-implantitis (P-I). Peri-implant crevicular fluid (PICF) and serum samples were collected from each participant. The levels of sST2 and IL-6 in PICF and sST2, IL-6, and CRP in serum were compared between the groups. Pocket depth (PD), modified bleeding index (mBI), modified plaque index (mPI), keratinized mucosa index (KTW), and gingival/mucosal recession (REC) were recorded as clinical parameters. Biomarkers in the serum and PICF were analyzed by ELISA kit.

RESULTS

Sixty-nine patients were included in the study. The differences in the following parameters were statistically significant between groups: age (p = .009), implant function time (p = .027), PD (p < .001), mBI (p < .001), mPI (p < .001), and KTW (p = .043). The PICF volume of P-I and PM groups were statistically higher than PH (p < .001). The amount of sST2 in P-I and PM groups were higher than PH (p = .043). Serum CRP was higher in the P-I group than in other groups (p = .034). There were no significant differences in serum sST2 (p = .247) and IL-6 (p = .110) levels between groups.

CONCLUSION

The PICF levels of sST2 were significantly higher in PM and P-I groups compared to the healthy group. However, no significant difference was observed between the groups in terms of serum sST2 level.

In-Vitro Biofilm Removal Efficacy Using Water Jet in Combination with Cold Plasma Technology on Dental Titanium Implants

Peri-implantitis-associated inflammation can lead to bone loss and implant failure. Current decontamination measures are ineffective due to the implants' complex geometry and rough surfaces providing niches for microbial biofilms. A modified water jet system (WaterJet) was combined with cold plasma technology (CAP) to achieve superior antimicrobial efficacy compared to cotton gauze treatment. Seven-day-old multi-species-contaminated titanium discs and implants were investigated as model systems. The efficacy of decontamination on implants was determined by rolling the implants over agar and determining colony-forming units supported by scanning electron microscopy image quantification of implant surface features. The inflammatory consequences of mono and combination treatments were investigated with peripheral blood mononuclear cell surface marker expression and chemokine and cytokine release profiles on titanium discs. In addition, titanium discs were assayed using fluorescence microscopy. Cotton gauze was inferior to WaterJet treatment according to all types of analysis. In combination with the antimicrobial effect of CAP, decontamination was improved accordingly. Mono and CAP-combined treatment on titanium surfaces alone did not unleash inflammation. Simultaneously, chemokine and cytokine release was dramatically reduced in samples that had benefited from additional antimicrobial effects through CAP. The combined treatment with WaterJet and CAP potently removed biofilm and disinfected rough titanium implant surfaces. At the same time, non-favorable rendering of the surface structure or its pro-inflammatory potential through CAP was not observed.

Silver Nanoparticles Produced by Laser Ablation and Re-Irradiation Are Effective Preventing Peri-Implantitis Multispecies Biofilm Formation

Implant-associated infection due to biofilm formation is a growing problem. Given that silver nanoparticles (Ag-NPs) have shown antibacterial effects, our goal is to study their effect against multispecies biofilm involved in the development of peri-implantitis. To this purpose, Ag-NPs were synthesized by laser ablation in de-ionized water using two different lasers, leading to the production of colloidal suspensions. Subsequently, part of each suspension was subjected to irradiation one and three times with the same laser source with which it was obtained. Ag-NPs were immobilized on the surface of titanium discs and the resultant materials were compared with unmodified titanium coupons. Nanoparticles were physico-chemically analysed to determine their shape, crystallinity, chemical composition, and mean diameter. The materials were incubated for 90 min or 48 h, to evaluate bacterial adhesion or biofilm formation respectively with Staphylococcus aureus or oral mixed bacterial flora composed of Streptococcus oralis, Actinomyces naeslundii, Veionella dispar, and Porphyromonas gingivalis. Ag-NPs help prevent the formation of biofilms both by S. aureus and by mixed oral bacterial flora. Nanoparticles re-irradiated three times showed the biggest antimicrobial effects. Modifying dental implants in this way could prevent the development of peri-implantitis.

Psychological risk indicators for peri-implantitis: A cross-sectional study

AIM

The aim of this analytical cross-sectional study was to evaluate the association between peri-implantitis and psychological distress, and potentially related/mediating factors such as general health, bruxism, and lifestyle factors.

MATERIALS AND METHODS

Patients who received dental implants at a private practice in the Netherlands between January 2011 and January 2014 were recalled on a 5-year clinical and radiographic follow-up examination. Presence of peri-implantitis was examined, and patients completed questionnaires measuring psychological distress (Symptom Checklist [SCL]-90), bruxism, general health, and lifestyle factors. Associations between the self-reported factors and peri-implantitis were analysed with univariate and multivariate logistic regression models.

RESULTS

A total of 230 patients (with 347 implants) were included in the analysis. Prevalence of (mild to severe) peri-implantitis was 30% (69 patients). Variables that showed a significant univariable association with peri-implantitis (p < .10) were the SCL-90 subdomain depression, smoking, current medical treatment, and lung problems. In the multivariate regression analysis, depression was the only variable that was significantly associated with peri-implantitis (p < .05).

CONCLUSIONS

The presence of depressive symptoms is a risk indicator for peri-implantitis. Recognizing the potential negative impact of depressive symptoms may allow for better identification of high-risk patients.

Comparison of Different Chemical and Mechanical Modalities for Implant Surface Decontamination: Activity against Biofilm and Influence on Cellular Regrowth—An In Vitro Study

Objectives

The aim of this in vitro study was to compare the efficacy of chemical and mechanical methods for decontamination of titanium dental implant surfaces previously infected with polymicrobial biofilms in a model simulating a peri-implant defect. Furthermore, the effect of each decontamination protocol on MG-63 osteoblast-like cells morphology and adhesion to the treated implants was assessed.

Background

Peri-implantitis is a growing issue in dentistry, and evidence about implant surface decontamination procedures is lacking and inconclusive.

Methods

A total of 40 previously biofilm-contaminated implants were placed into a custom-made model simulating a peri-implant defect and randomly assigned to five treatment groups: (C) control (no treatment); (AW) air abrasion without any powder; (ESC) air abrasion with powder of erythritol, amorphous silica, and 0.3% chlorhexidine; (HBX) decontamination with a sulfonic/sulfuric acid solution in gel; and (HBX + ESC) a combination of HBX and ESC. Microbiological analysis was performed on five implants per treatment group, and the residual viable bacterial load measured in log 10 CFU/mL was counted for each bacterial strain and for the total number of colonies. The remaining three implants per group and three noncontaminated (NC) implants were used to assess surface biocompatibility using a scanning electron microscope and a backscattered electron microscope after seeding with MG-63 cells.

Results

A significant decontaminant effect was achieved using HBX or HBX + ESC, while no differences were observed among other groups. The percentage of implant surface covered by adherent MG-63 cells was influenced by the treatment method. Progressive increases in covered surfaces were observed in groups C, AW, ESC, HBX, HBX + ESC, and NC.

Conclusions

A combination of mechanical and chemical decontamination may provide more predictable results than mechanical cleaning alone.

Antibacterial Adhesion Strategy for Dental Titanium Implant Surfaces: From Mechanisms to Application

Dental implants are widely used to restore missing teeth because of their stability and comfort characteristics. Peri-implant infection may lead to implant failure and other profound consequences. It is believed that peri-implantitis is closely related to the formation of biofilms, which are difficult to remove once formed. Therefore, endowing titanium implants with anti-adhesion properties is an effective method to prevent peri-implant infection. Moreover, anti-adhesion strategies for titanium implant surfaces are critical steps for resisting bacterial adherence. This article reviews the process of bacterial adhesion, the material properties that may affect the process, and the anti-adhesion strategies that have been proven effective and promising in practice. This article intends to be a reference for further improvement of the antibacterial adhesion strategy in clinical application and for related research on titanium implant surfaces.

Applications of Biodegradable Magnesium-Based Materials in Reconstructive Oral and Maxillofacial Surgery: A Review

Reconstruction of defects in the maxillofacial region following traumatic injuries, craniofacial deformities, defects from tumor removal, or infections in the maxillofacial area represents a major challenge for surgeons. Various materials have been studied for the reconstruction of defects in the maxillofacial area. Biodegradable metals have been widely researched due to their excellent biological properties. Magnesium (Mg) and Mg-based materials have been extensively studied for tissue regeneration procedures due to biodegradability, mechanical characteristics, osteogenic capacity, biocompatibility, and antibacterial properties. The aim of this review was to analyze and discuss the applications of Mg and Mg-based materials in reconstructive oral and maxillofacial surgery in the fields of guided bone regeneration, dental implantology, fixation of facial bone fractures and soft tissue regeneration.

MicroRNA sequence and function analysis in peri-implantitis and periodontitis: An animal study

OBJECTIVE

To compare miRNA expression levels and predict relevant target genes and signaling pathways in peri-implantitis and periodontitis.

BACKGROUND

There are many differences between periodontitis and peri-implantitis. An understanding of the similarities and differences in the transcriptional patterns of these diseases, as well as the molecular mechanisms, is beneficial for the development of management strategies.

MATERIALS AND METHODS

Rat models of periodontitis (PD, n = 6) and peri-implantitis (PI, n = 5) were established by ligation. Implantation without ligation (PIC, n = 5) and normal rats (PDC, n = 6) were used as controls. Micro-CT was used to confirm the successful establishment of the model. Gingiva was harvested for miRNA transcriptome sequencing, and the results were confirmed by qRT-PCR. miRNA target genes were predicted with miRTarBase. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses were performed.

RESULTS

Sixty-nine miRNAs were differentially expressed in PI vs. PD, 105 were differentially expressed in PI vs. PIC, and 70 were differentially expressed in PD vs. PDC (log₂ FC ≥1 and padj <0.05). The upregulated genes in all three comparisons were mostly involved in the biological process response to stimulus, whereas most of the downregulated genes were involved in nervous system development (p < .01). The upregulated genes in PI vs. PD and PI vs. PIC were involved in Toll-like receptor signaling and RIG-I-like signaling. The upregulated genes in PI vs. PD were involved in T- and B-cell receptor signaling, apoptosis, and osteoclast differentiation. Focal adhesion was downregulated in all three comparisons, and adherens junction was downregulated in PI vs. PD and PD vs. PDC (p < .1).

CONCLUSION

This study showed differences in the miRNA expression profiles between peri-implantitis and periodontitis and annotated the possible target genes and molecular mechanisms; this study could lay a foundation for the development of management strategies.

Transcription Factor AhR, Cytokines IL-6 and IL-22 in Subjects with and without Peri-Implantitis: A Case Control-Study

Peri-implantitis is a plaque-associated condition characterized by mucosal inflammation and subsequent progressive loss of supporting bone; it is caused by bacterial biofilm, but the host response triggered by bacterial stimulation promotes the release of cells and mediators that culminate in tissue destruction. The Aryl-hydrocarbon Receptor (AhR) is associated with IL-22 production by Th22 and Th17 CD4+ Th cells. The presence of IL-6 may promote the Th22 phenotype. The present case-control study evaluated the gene expression of AhR, IL-22, and IL-6 in the peri-implant tissues of healthy and peri-implantitis patients. Tissue biopsies were collected from thirty-five volunteers (15 healthy and 20 with peri-implantitis). A real-time PCR reaction was utilized to assess the AhR, IL-22, and IL-6 gene expression levels relative to the reference gene (GAPDH). The results were analyzed using the Mann-Whitney test with a significance level of 5%. Higher levels of gene expression of AhR and IL-6 were detected in peri-implantitis tissues. The IL-22 gene expression levels did not differ between groups. In conclusion, higher gene expression levels for AhR and IL-6 were detected in the soft tissues of peri-implantitis patients. IL-22 did not vary between conditions, which may indicate the loss of the immunomodulatory role of IL-22 in periimplantitis.