Periodontal infections: understanding the complexity--consensus of the Seventh European Workshop on Periodontology

Addressing Antimicrobial Properties in Guided Tissue/Bone Regeneration Membrane: Enhancing Effectiveness in Periodontitis Treatment

Guided tissue regeneration (GTR) and guided bone regeneration (GBR) are the two surgical techniques generally used for periodontitis disease treatment. These techniques are based on a barrier membrane to direct the growth of new bone and gingival tissue at sites with insufficient volumes or dimensions of bone or gingiva for proper function, esthetics, or prosthetic restoration. Numerous studies have highlighted biocompatibility, space-creation, cell-blocking, bioactivity, and proper handling as essential characteristics of a membrane's performance. Given that bacterial infection is the primary cause of periodontitis, we strongly believe that addressing the antimicrobial properties of these membranes is of utmost importance. Indeed, the absence of effective inhibition of periodontal pathogens has been recognized as a primary factor contributing to the failure of GTR/GBR membranes. Therefore, we suggest considering antimicrobial properties as one of the key factors in the design of GTR/GBR membranes. Antibiotics are potent medications frequently administered systemically to combat microbes and mitigate bacterial infections. Nevertheless, the excessive use of antibiotics has resulted in a surge in bacterial resistance. To overcome this challenge, alternative antibacterial substances have been developed. In this review, we explore the utilization of alternative substances with antimicrobial properties for topical application in membranes. The use of antibacterial nanoparticles, phytochemical compounds, and antimicrobial peptides in this context was investigated. By carefully selecting and integrating antimicrobial agents into GTR/GBR membranes, we can significantly enhance their effectiveness in combating periodontitis. These antibacterial substances not only act as barriers against pathogenic bacteria but also promote the process of periodontal healing.

Effect of functionalized titanium particles with dexamethasone-loaded nanospheres on macrophage polarization and activity

OBJECTIVE

The aim of this study was to determine the effect of titanium micro particles (TiP) previously functionalized with nanoparticles doped with dexamethasone (Dex) and doxycycline (Dox), on macrophage polarization and activity.

METHODS

Macrophages RAW264.7 were cultured in the presence TiP loaded with dexamethasone -NPs (Dex)- and doxycycline -NPs (Dox)-, and as control, TiP with or without doped NPs. Cells were tested with and without previous bacterial lipopolysaccharide endotoxin (LPS) stimulation. Their morphology, proliferation, cytotoxicity, phenotypic change, and cytokines release were assessed by LIVE/DEAD, DNA release, metabolic activity, brightfield and scanning electron microscopy. The test Kruskall-Wallis was used for comparisons, while the cytokine expression profiles were examined by hierarchical clustering (p < 0.05).

RESULTS

Upon exposure with TiP macrophages were activated and polarized to M1, but without depicting cytotoxic effects. The particles were phagocytised, and vacuolized. When exposed to functionalised TiP with NPs(Dex) and NPs(Dox), the ratio M1/M2 was up to forty times lower compared to TiP alone. When exposed to LPS, TiP reduced cell viability in half. Functionalised TiP with NPs(Dex) inhibited the cytokine release exerted by TiP on macrophages. When macrophages were exposed to functionalised TiPs with NPs(Dex) with and without LPS, the effect of TiP on cytokine secretion was inhibited.

SIGNIFICANCE

Functionalised TiPs with NPs(Dex) and NPs(Dox) may potentially have beneficial effects on modulating titanium and LPS-related inflammatory reactions.

Chronological analysis of periodontal bone loss in experimental periodontitis in mice

OBJECTIVES

Periodontal disease is understood to be a result of dysbiotic interactions between the host and the biofilm, causing a unique reaction for each individual, which in turn characterizes their susceptibility. The objective of this study was to chronologically evaluate periodontal tissue destruction induced by systemic bacterial challenge in known susceptible (BALB/c) and resistant (C57BL/6) mouse lineages.

MATERIAL AND METHODS

Animals, 6-8 weeks old, were allocated into three experimental groups: Negative control (C), Gavage with sterile carboxymethyl cellulose 2%-without bacteria (Sham), and Gavage with carboxymethyl cellulose 2% + Porphyromonas gingivalis (Pg-W83). Before infection, all animals received antibiotic treatment (sulfamethoxazole/trimethoprim, 400/80 mg/5 mL) for 7 days, followed by 3 days of rest. Microbial challenge was performed 3 times per week for 1, 2, or 3 weeks. After that, the animals were kept until the completion of 42 days of experiments, when they were euthanized. The alveolar bone microarchitecture was assessed by computed microtomography.

RESULTS

Both C57BL/6 and BALB/c mice exhibited significant bone volume loss and lower trabecular thickness as well as greater bone porosity compared to the (C) and (Sham) groups after 1 week of microbial challenge (p < .001). When comparing only the gavage groups regarding disease implantation, time and lineage, it was possible to observe that within 1 week of induction the disease was more established in BALB/c than in C57BL/6 (p < .05).

CONCLUSIONS

Our results reflected that after 1 week of microbial challenge, there was evidence of alveolar bone loss for both lineages, with the loss observed in BALB/c mice being more pronounced.

Porphyromonas gingivalis enhances the senescence-induced increase of 5-alpha reductase in gingival fibroblasts

OBJECTIVES

Aging is characterized by chronic inflammatory activity. Senescent cells increase with chronic inflammation and age-related pathologies, including periodontal disease. As a critical regulator of tissue inflammaging, we hypothesized that 5α reductase (5αR) is associated with periodontal disease and bacteria-induced senescence in gingival fibroblasts.

MATERIALS AND METHODS

We recruited 36 patients with periodontitis, measured 5αR immunohistochemically before and after periodontal treatment, and compared the expression of 5αR in gingival biopsies from 12 healthy individuals. We then tested the impact of Porphyromonas gingivalis on gingival fibroblasts treated with or without D-galactose-induced cell senescence. We treated primary gingival fibroblasts with D-galactose-supplemented media (0 µM, 50 µM, 100 µM, 1 mM, 10 mM, 50 mM) to induce senescence. The expression of type 1 and type 2 5αR was analyzed with real-time PCR and immunocytochemistry. The levels of IL-6, IL-8, TNF-α, and MCP-1 in fibroblast cultures were evaluated by multiplex immunoassay.

RESULTS

In gingival biopsies from patients with periodontal disease, the expression of 5αR was significantly higher than in samples from individuals without periodontal disease (p < 0.001). Periodontal treatment significantly reduced the expression of 5αR in gingival tissues (p < 0.001) to levels comparable in healthy individuals. Gingival fibroblasts exposed to D-galactose-supplemented media had a dose-dependent and significant increase in 5αR expression (p < 0.001). P. gingivalis caused statistically higher type 1 and type 2 5αR expression in gingival fibroblast cells. This effect was exacerbated by the lower doses of D-galactose (p = 0.037). Cells infected with P. gingivalis produced significantly higher levels of IL-6, IL-8, TNF-α, and MCP-1 (p < 0.05) regardless of the D-galactose exposure.

CONCLUSION

The results suggested that 5αR plays a role in periodontal disease and mediates the senescence-induced response to P. gingivalis in gingival fibroblasts.

CLINICAL RELEVANCE

Periodontal diseases and aging can increase the production of 5-alpha reductase in the gingival tissue.

Effect of doxycycline doped nanoparticles on osteogenic/cementogenic and anti-inflammatory responses of human cells derived from the periodontal ligament

OBJECTIVES

This work aimed to evaluate if doxycycline-doped polymeric nanoparticles possessed any anti-inflammatory effect and promote osteogenic/cementogenic differentiation of stem cells from human periodontal ligament (PDLSCs).

METHODS

The polymeric nanoparticles (NPs) were produced by a polymerization/precipitation process and doped with doxycycline (Dox-NPs). PDLSCs were cultured in the presence or absence of the NPs under osteogenic medium or IL-1β treatment. Cells' differentiation was assessed by gene expression analysis of osteogenic/cementogenic markers alkaline phosphatase (ALP) and Runt-related transcription factor 2 (RUNX2). An anti-inflammatory effect was also ascertained by analyzing IL-1β gene expression. Adipogenic and chondrogenic differentiation was used to confirm the multipotency of PDLSCs.

RESULTS

Gene expression of ALP and RUNX2 in PDLSCs was significantly upregulated by the osteogenic medium (ALP: p<0.001; RUNX2: p = 0.005) while Dox-NPs further enhanced ALP gene expression of PDLSCs treated with the osteogenic medium. Furthermore, Dox-NPs suppressed the up-regulation of IL-1β when cells were subjected to an inflammatory challenge.

CONCLUSIONS

Dox-NPs enhanced PDLSCs differentiation into osteoblasts/cementoblasts lineages while providing an anti-inflammatory effect.

CLINICAL SIGNIFICANCE

Due to their biocompatibility as well as anti-inflammatory and osteogenic/cementogenic effects, Dox-NPs are potential candidates for being used in periodontal regeneration.

Comparative analysis of antigen-presenting cells in gingival tissues in healthy and periodontitis patients

AIMS

Microbial flora of dental plaque trigger innate and adaptive immune responses. The function of antigen-presenting cells (APCs) is to bridge the innate and adaptive immune systems. The human immune system contains three main types of APCs: dendritic cells (DC) (Langerhans cells (LCs) and interstitial DCs, IDCs), macrophages and B lymphocytes. In this study, the distribution and density of all APCs in healthy and inflamed human gingival tissue were comparatively analysed.

METHODS

Research was conducted on gingival biopsy specimens obtained from 55 patients and classified in three groups: healthy gingiva (control group, n=10), moderate periodontal disease (PD) (n=21) and severe PD (n=24). For APCs' identification antibodies raised against CD_1a (for LCs), S₁₀₀ protein (for iDCs), CD₆₈ (for macrophages) and CD₂₀ (for B lymphocytes) were used.

RESULTS

Increased density of IDCs, macrophages and B lymphocytes in lamina propria and reduced density of LCs in the gingival epithelium were found in patients with periodontitis. Simultaneously, it was noticed an increased concentration of macrophages and B cells in the gingival epithelium in patients with PD. No statistically significant difference in the distribution and density of APC was found among patients with moderate and advanced periodontitis.

CONCLUSIONS

It was hypothesised that in the periodontitis the role of antigen presentation was largely taken from LCs by the DCs, macrophages and B cells. These APCs are thought to have less protective and tolerogenic potential than LCs and this is a significant reason for alveolar bone destruction in periodontitis.

Association of anxiety, age and oral health-related quality of life with periodontitis: A case-control study

OBJECTIVE

This case-control study evaluated the association of sociodemographic profile, mental health disorders and oral health-related quality of life (OHRQoL) with periodontitis.

METHODS

Patients with periodontitis (PP, n = 50) and control patients (CP, n = 50) were allocated into 2 groups after a complete periodontal examination. Data collection included age, sex, marital status, education and application of 2 questionnaires: Hospital Anxiety and Depression Scale for the diagnosis of anxiety/depression and Impact Profile on Oral Health (OHIP-14) for classification of well-being. An adjusted multiple binary logistic regression analysis was performed to assess the effect of all studied covariates on periodontitis.

RESULTS

The results show that mean clinical attachment loss and periodontal probing depth were 5.92 (SD = 0.42) and 5.46 (SD = 0.78) in PP and 0.00 (SD = 0.00) and 2.85 (SD = 0.23) in CP, respectively (p < 0.001). The regression analysis demonstrated a significant effect on periodontitis for age (OR = 1.13; p < 0.0001; 95% CI: 1.07-1.20), with the PP having more people aged 50 years or older than CP, anxiety (OR = 1.25; p = 0.020; 95% CI: 1.04-1.50) and OHIP-14 (OR = 1.17; p < 0.0001; 95% CI: 1.08-1.226).

CONCLUSIONS

The findings showed a positive association between anxiety, OHRQoL and age with periodontitis.

Illegal drugs and periodontal conditions

In recent years, the practice of dentistry and periodontology has become complicated by several risk factors, including the treatment of an increasing number of patients with substance use disorder. This review presents an update in the current literature of the impact of illegal drug use on periodontal conditions and their possible effect as risk factors or indicators. The main illegal drugs that may have an impact on periodontal health and conditions are described, including their effect, medical manifestations, risks, and the overall effect on oral health and on the periodontium. Where available, data from epidemiologic studies are analyzed and summarized. The clinical management of periodontal patients using illegal drugs is reported in a comprehensive approach inclusive of the detection of illicit drug users, screening, interviewing and counseling, the referral to treatment, and the dental and periodontal management. With regard to the impact of illegal substance use on periodontal conditions, there is moderate evidence that regular long-term use of cannabis is a risk factor for periodontal disease, manifesting as a loss of periodontal attachment, deep pockets, recessions, and gingival enlargements. Limited evidence also shows that the use of cocaine can cause a series of gingival conditions that mostly presents as chemical induced-traumatic lesions (application of cocaine on the gingiva) or necrotizing ulcerative lesions. There is a scarcity of data regarding the impact of other drug use on periodontal health. There is evidence to suggest that regular long-term use of cannabis is a risk factor for periodontal disease and that the use of cocaine can cause a series of periodontal conditions. The dental treatment of subjects that use illegal substances is becoming more common in the daily clinical practice of periodontists and other dental clinicians. When the clinicians encounter such patients, it is essential to manage their addiction properly taking into consideration the impact of it on comprehensive dental treatment. Further studies and clinical observations are required to obtain sound and definitive information.

Correlation Analysis of Gut Microbiota and Serum Metabolome With Porphyromonas gingivalis-Induced Metabolic Disorders

Periodontitis has been demonstrated to increase the risk of metabolic syndrome (MetS), but the underlying mechanism remains unclear. Recent studies have indicated periodontopathic bacteria such as Porphyromonas gingivalis could induce gut microbiota (GM) dysbiosis and aggravate metabolic disorders. However, the effects of microbial metabolites have barely been evaluated. Here, we investigated the alteration of serum metabolome with P. gingivalis-induced metabolic disorders, and explored the correlations of GM and serum metabolites. In this study, we orally administered P. gingivalis ATCC33277 to C57BL/6 mice and performed metagenomic sequencing and untargeted metabolomics with fecal samples and serum collection. In vivo experiments showed a higher proportion of fat mass and worse glucose tolerance in P. gingivalis-administered mice, accompanied with an increase of adipose inflammation and gut permeability, which was similar to HFD-induced obese mice. Metagenomic sequencing indicated a compositional and functional alteration of GM. Untargeted metabolomics revealed an alteration of metabolites in P. gingivalis-administered mice, and most of them were engaged in metabolic pathways, such as tryptophan metabolism and choline metabolism. Correlation analysis between GM and serum metabolome indicated strong relativity with P. gingivalis administration. These results demonstrated some specific microbiota-derived metabolites in the pathogenesis of P. gingivalis-induced metabolic disorders, providing promising targets for the development of novel treatment strategies for MetS.

Sarcopenic Dysphagia, Malnutrition, and Oral Frailty in Elderly: A Comprehensive Review

Frailty is a highly prevalent condition in the elderly that has been increasingly considered as a crucial public health issue, due to the strict correlation with a higher risk of fragility fractures, hospitalization, and mortality. Among the age-related diseases, sarcopenia and dysphagia are two common pathological conditions in frail older people and could coexist leading to dehydration and malnutrition in these subjects. “Sarcopenic dysphagia” is a complex condition characterized by deglutition impairment due to the loss of mass and strength of swallowing muscles and might be also related to poor oral health status. Moreover, the aging process is strictly related to poor oral health status due to direct impairment of the immune system and wound healing and physical and cognitive impairment might indirectly influence older people’s ability to carry out adequate oral hygiene. Therefore, poor oral health might affect nutrient intake, leading to malnutrition and, consequently, to frailty. In this scenario, sarcopenia, dysphagia, and oral health are closely linked sharing common pathophysiological pathways, disabling sequelae, and frailty. Thus, the aim of the present comprehensive review is to describe the correlation among sarcopenic dysphagia, malnutrition, and oral frailty, characterizing their phenotypically overlapping features, to propose a comprehensive and effective management of elderly frail subjects.

A lingering mouthwash with sustained antibiotic release and biofilm eradication for periodontitis

Dental plaque biofilms are believed to be one of the principal virulence factors in periodontitis resulting in tooth loss. Traditional mouthwashes are limited due to the continuous flow of saliva and poor drug penetration ability in the biofilm. Herein, we fabricated an antibiotic delivery platform based on natural polysaccharides (chitosan and cyclodextrin) as a novel mouthwash for the topical cavity delivery of minocycline. The penetration and residence mechanisms demonstrate that the platform can prolong the residence time up to 12 h on biofilms. Furthermore, sustained release can enhance the penetration of drugs into biofilms. In vitro antibiofilm experimental results indicated that the mouthwash effectively kills bacteria and eradicate biofilms. Effective treatment in vivo was confirmed by the significantly reduced dental plaque and alleviated inflammation observed in a rat periodontitis model. In summary, this novel platform can improve antibiofilm efficiency and prevent drugs from being washed away by saliva, which may provide benefits for many oral infectious diseases.

Investigation of Salivary RANKL and OPG Levels in Periodontitis Patients at Hospital Universiti Sains Malaysia

Objective  This study was aimed to determine the levels of salivary receptor activator of NF-κB ligand (RANKL) and osteoprotegerin (OPG) and its association with periodontal status among periodontitis patients.

Materials and Methods  A cross-sectional study was designed and performed at the Dental Clinic, Hospital Universiti Sains Malaysia (HUSM). Random sampling was employed to identify 88 participants into three groups: 30 mild periodontitis, 30 moderate to severe periodontitis, and 28 healthy (nonperiodontitis) patients. Periodontal parameters: periodontal pocket depth (PPD), clinical attachment level (CAL), plaque score (PS), and gingival bleeding index (GBI) were recorded. In total, 4 mL of unstimulated whole saliva was collected to determine the levels of salivary RANKL and OPG proteins by using ELISA technique. Data were analyzed by using SPSS software version 24.0.

Results  Mean values for PPD (5.3 ± 0.5) and CAL (5.6 ± 0.5) were observed higher for moderate to severe periodontitis as compared with values (4.4 ± 0.2) (4.5 ± 0.2) in mild periodontitis patients. The mean salivary RANKL and OPG was 0.23 ± 0.07 ng/mL and 1.78 ± 0.70 ng/mL respectively in moderate to severe periodontitis. Only salivary RANKL levels were significantly and positively correlated with all the clinical periodontal parameters.

Conclusion  The levels of salivary RANKL were higher as opposed to lower OPG levels in periodontitis patients in contrast to healthy (nonperiodontitis) patients. RANKL levels were significantly associated with the periodontal parameters. Therefore, we can conclude that RANKL can potentially aid as an adjunctive diagnostic protein in evaluating periodontal disease.

Reduction of hsCRP levels following an Oral Health Education Program combined with routine dental treatment

OBJECTIVES

The present study aimed to determine the effect of a personalised oral health education program, in combination with routine dental treatment, on serum biomarkers of systemic disease compared to dental treatment alone in a population from a low-socioeconomic community with poor oral health.

METHODS

This secondary analysis of a randomised clinical trial involved 295 participants (mean age, 45.4 ± 11 years) assigned to two groups. One group received dental treatment combined with the Oral Health Education Program (OHEPDT), while the second group (DT) received dental care without the Education Program. Serum levels of high-sensitivity C-reactive protein (hsCRP), lipid profile (total cholesterol, triglycerides, and high- and low-density lipoprotein cholesterol), and HbA1c levels were analysed at baseline and after 12 months. Changes in diet, smoking and alcohol consumption were also determined.

RESULTS

No intergroup differences were observed for the lipid profile and HbA1c levels. A reduction in the hsCRP levels at the 12-month follow-up was observed in the OHEPDT group, which was significantly different from the DT group (p = 0.01). Multivariate modelling indicated that baseline hsCRP levels (p = 0.000), baseline body mass index (p = 0.000), and higher consumption of vegetables (p = 0.021) predicted a reduction in hsCRP levels.

CONCLUSIONS

This study demonstrated that personalised oral health education combined with routine dental treatment was associated with a significant reduction in hsCRP levels subsequent to dietary behavioural changes. These findings suggest that personalised oral health education in combined with routine dental treatment may have beneficial effects on general health.

CLINICAL SIGNIFICANCE

The strategy for developing an oral health program that involves education of the modifiable common risk factors for general health has beneficial effects and should be one of the priority components of these programs to improve oral and general health, particularly for at-risk communities.

Polymeric zinc-doped nanoparticles for high performance in restorative dentistry

OBJECTIVES

The aim was to state the different applications and the effectiveness of polymeric zinc-doped nanoparticles to achieve dentin remineralization.

DATA, SOURCES AND STUDY SELECTION

Literature search was conducted using electronic databases, such as PubMed, MEDLINE, DIMDI, Embase, Scopus and Web of Science. A narrative exploratory review was undertaken.

CONCLUSIONS

Polymeric nanospheres (NPs) were efficiently loaded with zinc. NPs sequestered calcium and phosphate in the presence of silicon, and remained effectively embedded at the hybrid layer. NPs incorporation did not alter bond strength and inhibited MMP-mediated dentin collagen degradation. Zn-loaded NPs remineralized the hybrid layer inducing a generalized low-carbonate substitute apatite precipitation, chemically crystalline with some amorphous components, and an increase in mechanical properties was also promoted. Viscoelastic analysis determined that dentin infiltrated with Zn-NPs released the stress by breaking the resin-dentin interface and creating specific mineral formations in response to the energy dissipation. Bacteria were scarcely encountered at the resin-dentin interface. The combined antibacterial and remineralizing effects, when Zn-NPs were applied, reduced biofilm formation. Zn-NPs application at both cervical and radicular dentin attained the lowest microleakage and also promoted durable sealing ability. The new zinc-based salt minerals generated covered the dentin surface totally occluding cracks, porosities and dentinal tubules.

CLINICAL SIGNIFICANCE

Zinc-doped NPs are proposed for effective dentin remineralization and tubular occlusion. This offers new strategies for regeneration of eroded cervical dentin, effective treatment of dentin hypersensitivity and in endodontically treated teeth previous to the canal filling. Zn-NPs also do reduce biofilm formation due to antibacterial properties.

The Effects of 6-Month Vitamin D Supplementation during the Non-Surgical Treatment of Periodontitis in Vitamin-D-Deficient Patients: A Randomized Double-Blind Placebo-Controlled Study

BACKGROUND

This study assessed the effects of weekly vitamin D (VD) supplementation on clinical and biological parameters after scaling and root planning (SRP) in the treatment of periodontitis and served to validate the VD dosage regimen.

METHODS

It was a monocentric, randomized, double-blind, placebo-controlled clinical trial with 6 months follow-up. Healthy Caucasian periodontitis patients presenting serum 25(OH) vitamin D3 below 30 ng/mL were randomly allocated to test group (SRP + VD 25,000 international units (IU)/week) or the control group (SRP + placebo).

RESULTS

A total of 59 patients were screened, 27 were included and 26 completed 3 months (M) and 21 completed 6M control. Test (n = 13) and control groups (n = 14) had similar 25(OH) vitamin D3 levels at baseline (17.6 ± 7.4 vs. 14.4 ± 5.2, respectively). After one month, there was a significant difference between groups (32.9 ± 5.2 vs. 16.1 ± 4.7), also seen at M3 and M6 (t-test, p < 0.001). Periodontal treatment was successful in both groups, since it resulted in a reduction of all measured clinical parameters at M3 and M6 (probing pocket depth (PPD), full mouth bleeding and plaque). However, the reduction in PPD was greater in the test group.

CONCLUSIONS

In this short-term pilot study, no significant differences were observed between two groups. However, supplementation with VD tended to improve the treatment of periodontitis in patients with initial 25(OH) vitamin D3 < 30 ng/mL and proved safe and efficacious. NCT03162406.

Sulfate-Reducing Bacteria of the Oral Cavity and Their Relation with Periodontitis-Recent Advances

The number of cases of oral cavity inflammation in the population has been recently increasing, with periodontitis being the most common disease. It is caused by a change in the microbial composition of the biofilm in the periodontal pockets. In this context, an increased incidence of sulfate-reducing bacteria (SRB) in the oral cavity has been found, which are a part of the common microbiome of the mouth. This work is devoted to the description of the diversity of SRB isolated from the oral cavity. It also deals with the general description of periodontitis in terms of manifestations and origin. It describes the ability of SRB to participate in its development, although their effect on periodontal inflammation is not fully understood. The production of hydrogen sulfide as a cytochrome oxidase inhibitor may play a role in the etiology. A meta-analysis was conducted based on studies of the occurrence of SRB in humans.

The effect of doxycycline-containing chitosan/carboxymethyl chitosan nanoparticles on NLRP3 inflammasome in periodontal disease

A polyelectrolyte complex nanoparticle comprising chitosan (CS) and carboxymethyl chitosan (CMCS) was prepared (CS/CMCS-NPs) by ionic gelation, which was then used as a doxycycline carrier (Dox:CS/CMCS-NPs). The obtained CS/CMCS-NPs and Dox:CS/CMCS-NPs were characterized for various parameters and bacteriostatic ability against Porphyromonas gingivalis. The regulation of related genes and proteins of NLRP3 inflammasome and IL-1β in human gingival fibroblasts (HGFs) was characterized by qRT-PCR, western blotting and ELISA. The results showed that Dox:CS/CMCS-NPs had an orderly morphology and an excellent cytocompatibility. P. gingivalis was strongly inhibited by Dox:CS/CMCS-NPs contrasted with control group. Dox:CS/CMCS-NPs effectively down-regulated both gene and protein levels of NLRP3 inflammasome and IL-1β in HGFs. This study provides a new method for rational application of Dox in the clinical treatment of periodontal disease and a new direction for explaining the mechanism of action of Dox:CS/CMCS-NPs and more drug-carrying nanoparticles.

Salivary levels of specialized pro-resolving lipid mediators as indicators of periodontal health/disease status

AIM

This cross-sectional case-control study aimed to determine if salivary levels of lipoxin A4 (LXA4), protectin D1 (PD1), resolvin E1 (RvE1) and maresin 1 (MaR1) might constitute a reflection of periodontal health/disease status.

MATERIALS AND METHODS

One hundred and two periodontitis patients and 61 healthy controls were recruited. Periodontal clinical status was determined by criteria based on full-mouth clinico-radiographical data. Salivary concentration of the analytes was calculated by enzyme-linked immunosorbent assay. The association between the biomarkers with disease status was assessed individually and adjusted for confounding using multivariate binary logistic regression models.

RESULTS

Significantly decreased LXA4 and increased PD1/MaR1 salivary levels were detected in periodontitis patients in comparison with healthy controls. However, no significant differences were observed for RvE1 levels between clinical groups. Clinical parameters such as probing depth, clinical attachment loss and extent were negatively correlated with LXA4, positively correlated with PD1/MaR1 and not correlated with RvE1 salivary levels. Logistic regression analyses revealed a strong/independent association of LXA4, PD1 and MaR1 salivary levels regarding disease status. Interaction effects between demographic predictor variables and salivary concentration of LXA4, PD1 and MaR1 were also identified.

CONCLUSION

The results of this study demonstrated a strong/independent association between reduced LXA4 and increased PD1/MaR1 salivary levels with periodontitis suggesting an imbalance in the specialized pro-resolving lipid mediators (SPMs) in periodontal disease.

Home use of interdental cleaning devices, in addition to toothbrushing, for preventing and controlling periodontal diseases and dental caries

BACKGROUND

Dental caries (tooth decay) and periodontal diseases (gingivitis and periodontitis) affect the majority of people worldwide, and treatment costs place a significant burden on health services. Decay and gum disease can cause pain, eating and speaking difficulties, low self-esteem, and even tooth loss and the need for surgery. As dental plaque is the primary cause, self-administered daily mechanical disruption and removal of plaque is important for oral health. Toothbrushing can remove supragingival plaque on the facial and lingual/palatal surfaces, but special devices (such as floss, brushes, sticks, and irrigators) are often recommended to reach into the interdental area.

OBJECTIVES

To evaluate the effectiveness of interdental cleaning devices used at home, in addition to toothbrushing, compared with toothbrushing alone, for preventing and controlling periodontal diseases, caries, and plaque. A secondary objective was to compare different interdental cleaning devices with each other.

SEARCH METHODS

Cochrane Oral Health's Information Specialist searched: Cochrane Oral Health's Trials Register (to 16 January 2019), the Cochrane Central Register of Controlled Trials (CENTRAL) (the Cochrane Library, 2018, Issue 12), MEDLINE Ovid (1946 to 16 January 2019), Embase Ovid (1980 to 16 January 2019) and CINAHL EBSCO (1937 to 16 January 2019). The US National Institutes of Health Trials Registry (ClinicalTrials.gov) and the World Health Organization International Clinical Trials Registry Platform were searched for ongoing trials. No restrictions were placed on the language or date of publication.

SELECTION CRITERIA

Randomised controlled trials (RCTs) that compared toothbrushing and a home-use interdental cleaning device versus toothbrushing alone or with another device (minimum duration four weeks).

DATA COLLECTION AND ANALYSIS

At least two review authors independently screened searches, selected studies, extracted data, assessed studies' risk of bias, and assessed evidence certainty as high, moderate, low or very low, according to GRADE. We extracted indices measured on interproximal surfaces, where possible. We conducted random-effects meta-analyses, using mean differences (MDs) or standardised mean differences (SMDs).

MAIN RESULTS

We included 35 RCTs (3929 randomised adult participants). Studies were at high risk of performance bias as blinding of participants was not possible. Only two studies were otherwise at low risk of bias. Many participants had a low level of baseline gingival inflammation.Studies evaluated the following devices plus toothbrushing versus toothbrushing: floss (15 trials), interdental brushes (2 trials), wooden cleaning sticks (2 trials), rubber/elastomeric cleaning sticks (2 trials), oral irrigators (5 trials). Four devices were compared with floss: interdental brushes (9 trials), wooden cleaning sticks (3 trials), rubber/elastomeric cleaning sticks (9 trials) and oral irrigators (2 trials). Another comparison was rubber/elastomeric cleaning sticks versus interdental brushes (3 trials).No trials assessed interproximal caries, and most did not assess periodontitis. Gingivitis was measured by indices (most commonly, Löe-Silness, 0 to 3 scale) and by proportion of bleeding sites. Plaque was measured by indices, most often Quigley-Hein (0 to 5).

PRIMARY OBJECTIVE

comparisons against toothbrushing aloneLow-certainty evidence suggested that flossing, in addition to toothbrushing, may reduce gingivitis (measured by gingival index (GI)) at one month (SMD -0.58, 95% confidence interval (CI) -1.12 to -0.04; 8 trials, 585 participants), three months or six months. The results for proportion of bleeding sites and plaque were inconsistent (very low-certainty evidence).Very low-certainty evidence suggested that using an interdental brush, plus toothbrushing, may reduce gingivitis (measured by GI) at one month (MD -0.53, 95% CI -0.83 to -0.23; 1 trial, 62 participants), though there was no clear difference in bleeding sites (MD -0.05, 95% CI -0.13 to 0.03; 1 trial, 31 participants). Low-certainty evidence suggested interdental brushes may reduce plaque more than toothbrushing alone (SMD -1.07, 95% CI -1.51 to -0.63; 2 trials, 93 participants).Very low-certainty evidence suggested that using wooden cleaning sticks, plus toothbrushing, may reduce bleeding sites at three months (MD -0.25, 95% CI -0.37 to -0.13; 1 trial, 24 participants), but not plaque (MD -0.03, 95% CI -0.13 to 0.07).Very low-certainty evidence suggested that using rubber/elastomeric interdental cleaning sticks, plus toothbrushing, may reduce plaque at one month (MD -0.22, 95% CI -0.41 to -0.03), but this was not found for gingivitis (GI MD -0.01, 95% CI -0.19 to 0.21; 1 trial, 12 participants; bleeding MD 0.07, 95% CI -0.15 to 0.01; 1 trial, 30 participants).Very-low certainty evidence suggested oral irrigators may reduce gingivitis measured by GI at one month (SMD -0.48, 95% CI -0.89 to -0.06; 4 trials, 380 participants), but not at three or six months. Low-certainty evidence suggested that oral irrigators did not reduce bleeding sites at one month (MD -0.00, 95% CI -0.07 to 0.06; 2 trials, 126 participants) or three months, or plaque at one month (SMD -0.16, 95% CI -0.41 to 0.10; 3 trials, 235 participants), three months or six months, more than toothbrushing alone.

SECONDARY OBJECTIVE

comparisons between devicesLow-certainty evidence suggested interdental brushes may reduce gingivitis more than floss at one and three months, but did not show a difference for periodontitis measured by probing pocket depth. Evidence for plaque was inconsistent.Low- to very low-certainty evidence suggested oral irrigation may reduce gingivitis at one month compared to flossing, but very low-certainty evidence did not suggest a difference between devices for plaque.Very low-certainty evidence for interdental brushes or flossing versus interdental cleaning sticks did not demonstrate superiority of either intervention.Adverse eventsStudies that measured adverse events found no severe events caused by devices, and no evidence of differences between study groups in minor effects such as gingival irritation.

AUTHORS' CONCLUSIONS

Using floss or interdental brushes in addition to toothbrushing may reduce gingivitis or plaque, or both, more than toothbrushing alone. Interdental brushes may be more effective than floss. Available evidence for tooth cleaning sticks and oral irrigators is limited and inconsistent. Outcomes were mostly measured in the short term and participants in most studies had a low level of baseline gingival inflammation. Overall, the evidence was low to very low-certainty, and the effect sizes observed may not be clinically important. Future trials should report participant periodontal status according to the new periodontal diseases classification, and last long enough to measure interproximal caries and periodontitis.

Homeopathy and Periodontal Treatment in Type II Diabetic Patients: a 1-Year Randomized Clinical Trial

Abstract Chronic periodontitis (CP) and Diabetes mellitus type 2 (DMII) are chronic diseases usually treated by conventional practices. On the other hand, homeopathy can help to treat many different diseases. The aim of this study was to evaluate the effects of homeopathy (H) as an adjunct for non-surgical periodontal therapy (NSPT) in individuals with DMII and CP. Eighty individuals with CP and DM II, of both sexes and aged between 32 and 70 years, participated in this randomized, double-blind, placebo-controlled study. They were divided into two groups: control group (CG) and the test group (TG), and both groups received the NSPT. TG also received homeopathic therapy, including Berberis, Mercurius solubilis/Belladonna/Hepar sulphur and Pyrogenium, while CG received placebo. Clinical and laboratorial examinations were evaluated at baseline and after 1, 6 and 12 months of treatment. Both groups showed significant improvement throughout the study, for most of the parameters studied, but TG presented significative gain of CAL at 1 and 12 months compared to CG. Mean glucose and glycated hemoglobin significantly decreased in both groups after 6 and 12 months. However, there was a significantly further reduction of these parameters in TG, as compared to CG. In conclusion, homeopathy as supplement of NSPT may further improve health condition, including glycemic control, in DMII patients with CP.

Detection and quantification of Porphyromonas gingivalis and Aggregatibacter actinomycetemcomitans in bacteremia induced by interdental brushing in periodontally healthy and periodontitis patients

OBJECTIVE

This study was aimed to compare the presence and amounts of bacteremia induced by interdental brushing in periodontally healthy (H) and periodontitis (P) individuals using culture based (direct culture [DC]) and molecular based techniques (real-time quantitative polymerase chain reaction [qPCR]) in a cross-sectional study model.

MATERIALS AND METHODS

After a full mouth periodontal evaluation, blood samples were taken before and 1 min after professionally-administered interdental brushing. These samples were analyzed by DC and qPCR, targeting Porphyromonas gingivalis and Aggregatibacter actinomycetemcomitans. Subgingival samples were also collected and analyzed. Student t-test, chi-squar tests and correlations were used for analyzing the data.

RESULTS

Thirty individuals per group were included. P. gingivalis and A. actinomycetemcomitans were detected with qPCR methods, but not with DC. At baseline, bacteremia was observed in 5 P patients (16.7%) and in 2 H individuals (6.6%) (p = 0.421). After interdental brushing, bacteremia was only observed in 2 P patients (6.6%) (p = 0.901). A positive correlation between subgingival and blood levels of A. actinomycetemcomitans was observed (r = 0.3; p = 0.013).

CONCLUSION

Bacteremia related to A. actinomycetemcomitans and P. gingivalis did not significantly increase after a single session of use of interdental brushes.

Increased Risk of Ulcerative Colitis in Patients with Periodontal Disease: A Nationwide Population-Based Cohort Study

Both periodontal disease (PD) and inflammatory bowel disease (IBD), including Crohn's disease (CD) and ulcerative colitis (UC), are important diseases of the alimentary tract. Microbiome and immune-mediated inflammatory processes play important roles in these diseases. An association between PD and IBD may exist. This study investigated the risk of IBD in patients with PD. This study used data from the National Health Insurance Research Database of Taiwan from 1996 to 2013. A total of 27,041 patients with PD were enrolled as a study group, and 108,149 patients without PD were selected as the control group after matching by gender, age, insured region, urbanization, and income with a 1:4 ratio. Cox proportional hazards regression was used to calculate the risk of IBD. Of the 135,190 participants enrolled in this study, 5392 (4%) with newly diagnosed IBD were identified. The overall incidence of subsequent IBD was similar in both groups (3.8% vs. 4%, adjusted hazard ratio (aHR) = 1.01, 95% confidence interval (CI): 0.94⁻1.08). However, an increased risk of UC in the PD group was found after adjusting confounding factors (aHR: 1.56, 95% CI: 1.13⁻2.15; p < 0.05). This study demonstrated that patients with PD had approximately one-half higher risk of subsequent UC. Further studies are warranted to elucidate the relationship between PD and UC.

Evaluation of lozenges containing egg yolk antibody against Porphyromonas gingivalis gingipains as an adjunct to conventional non-surgical therapy in periodontitis patients: A randomized controlled clinical trial

BACKGROUND

In a previous pilot study, one-time application of anti-Porphyromonas gingivalis gingipain egg yolk immunoglobulin (IgY) into scaling and root planing (SRP)-treated periodontal pockets showed profound improvement of clinical and bacteriological parameters in patients with chronic periodontitis. The present study aims to evaluate the efficacy of daily use of lozenges fortified with the antibody as an adjunct to non-surgical therapy in patients with periodontitis.

METHODS

Sixty-four patients with periodontitis were divided randomly into a test and a placebo group. The groups were treated by SRP followed by a daily use of lozenges containing either specific IgY against P. gingivalis gingipains (test) or a sham-immune IgY (placebo). Gingival bleeding index (GBI), probing pocket depth (PD) and quantitation of P. gingivalis in the gingival pockets were assessed at baseline and 8 weeks after the initiation of treatment and compared by using Wilcoxon signed rank test, Mann-Whitney U-test or t test.

RESULTS

Both groups showed significant improvement of all parameters at 8 weeks post treatment (P < 0.001). There was a significant difference in reduction of GBI (P < 0.001) and P. gingivalis cell counts (P < 0.05) in the test group compared with the placebo group. The reduction of PD was greater in the test group compared with the placebo group although there was no statistically significant difference between the two groups.

CONCLUSIONS

The adjunctive use of lozenges containing IgY antibody against gingipains from P. gingivalis resulted in clinical and microbiological benefits in the treatment for chronic periodontitis. Additional investigations are needed to examine if the IgY brings benefits to case patients who do not receive SRP.

Antimicrobial peptide gene expression in periodontitis patients: A pilot study

AIM

Antimicrobial peptides (AMPs) are one of the most active components of innate immunity and have characteristics that could place them at the heart of the pathogenesis of periodontal disease. This study investigated differences in the expression of AMP coding genes obtained using a simple harvesting technique, gingival smear, between two groups of patients: chronic periodontitis subjects versus healthy ones.

MATERIALS AND METHODS

Twenty-three patients were enrolled in two groups: 12 were diagnosed with moderate or severe generalized chronic periodontitis, and 11 were diagnosed as clinically healthy. Gingival smears were retrieved and studied using reverse transcription-quantitative PCR (RT-qPCR) after mRNA purification.

RESULTS

Fifteen gene expressions were obtained using real-time RT-qPCR. Three AMP genes, histatin 3 (HTN3), α-defensin 4 (DEFA4) and lysozyme C (LYZ), presented different expression levels in periodontitis patients compared with healthy subjects. The relative expression level of DEFA4 appeared to be a protective factor against periodontitis.

CONCLUSION

Gingival smears studied by RT-qPCR may be used to assess the expression of AMPs coding genes. A lack of expression of DEFA4 could be a potential indicator of periodontitis status.

Clinical and microbiological effects of egg yolk antibody against Porphyromonas gingivalis as an adjunct in the treatment of moderate to severe chronic periodontitis: a randomized placebo-controlled clinical trial

Purpose

To evaluate the clinical and microbiological effects of the local use of egg yolk immunoglobulin against Porphyromonas gingivalis (anti-P.g. IgY) as an adjunct to scaling and root planing (SRP) in the treatment of moderate to severe chronic periodontitis.

Methods

This was a randomized, placebo-controlled, double-blind trial involving 60 systematically healthy patients with moderate to severe chronic periodontitis. Subjects (n=20/group) were randomly assigned to receive SRP combined with subgingival irrigation of anti-P.g. IgY and anti-P.g. IgY mouthwash, subgingival irrigation of 0.2% chlorhexidine and 0.2% chlorhexidine mouthwash, or subgingival irrigation of placebo and placebo mouthwash for 4 weeks. Probing pocket depth, clinical attachment level, bleeding on probing, and the plaque index were evaluated at baseline and at 4 weeks. Subgingival plaque, gingival crevicular fluid, and saliva were simultaneously collected for microbiological analysis.

Results

Our results showed that anti-P.g. IgY mouthwash was as effective as chlorhexidine at improving clinical parameters over a 4-week period. All the groups showed a significant reduction in levels of P.g. at 4 weeks. No significant difference was observed in the test group when compared to placebo regarding the reduction in the levels of P.g. Anti-P.g. IgY significantly suppressed the numbers of red complex bacteria (RCB) in subgingival plaque and saliva in comparison with placebo. No adverse effects were reported in any of the subjects.

Conclusions

Within the limitations of the study, the present investigation showed that passive immunization with anti-P.g. IgY may prove to be effective in the treatment of chronic periodontitis due to its ability to improve clinical parameters and to reduce RCB. No significant differences were found between the anti-P.g. IgY and placebo groups in the reduction of P.g.

Comparison of clinical parameters, microbiological effects and calprotectin counts in gingival crevicular fluid between Er: YAG laser and conventional periodontal therapies: A split-mouth, single-blinded, randomized controlled trial

BACKGROUND

The erbium-doped yttrium, aluminum, and garnet (Er:YAG) laser is thought to be the most promising laser for periodontal treatment; however, its application is still under consideration. The aim of this study was to compare Er:YAG laser monotherapy with conventional scaling and root planing (SRP) for chronic periodontitis using clinical parameters, the detection rate of periodontal pathogens, and the calprotectin level in gingival crevicular fluid.

METHODS

Twenty-seven participants with moderate-to-advanced chronic periodontitis were included. In a split-mouth design, the 2 half-mouths of each participant were randomly assigned to Er:YAG laser or SRP (combination of ultrasonic and manual instruments) treatment. Clinical parameters were recorded at baseline, 6 weeks, and 3 and 6 months after treatment. At the same time points, gingival crevicular fluid was collected to analyze the detection rate of 6 periodontal pathogens by polymerase chain reaction and the levels of calprotectin by enzyme-linked immunosorbent assay.

RESULTS

Both treatment groups showed significant reductions in probing depth (PD), bleeding index (BI), and clinical attachment level (CAL) from baseline to 6 months. For sites with 4 mm ≤ PD ≤ 6 mm at baseline, SRP resulted in a greater reduction in PD and CAL than Er:YAG laser treatment, and the difference remained at 6 months post-treatment (P = .01 and P < .01, respectively). For sites with PD ≥7 mm at baseline, the clinical parameters showed similar results between the 2 groups. SRP resulted in a lower detection rate of Porphyromonas gingivalis at 6 months post-treatment. The levels of calprotectin were significantly decreased from baseline to 6 months in both groups, without a significant difference between the groups.

CONCLUSION

For mild pockets, conventional SRP may still be the preferred choice. For deep pockets, Er:YAG laser treatment could be an effective alternative. Studies are needed to explore more advanced instruments and new application methods for the Er:YAG laser for periodontal treatment in deep pockets.

The role of 5-lipoxygenase in Aggregatibacter actinomycetemcomitans-induced alveolar bone loss

AIM

Leukotrienes (LTs) are pro-inflammatory lipid mediators formed by the enzyme 5-lipoxygenase (5-LO). The involvement of 5-LO metabolites in periodontal disease (PD) is not well defined. This study aimed to assess the role of 5-LO in experimental PD induced by Aggregatibacter actinomycetemcomitans (Aa).

MATERIAL AND METHODS

In vivo experiments were carried out using SV129 wild-type (WT) and 5-LO-deficient (5lo^-/- ) mice inoculated with Aa. Osteoclasts were stimulated in vitro with AaLPS in the presence or not of selective inhibitors of the 5-LO pathway, or LTB4 or platelet-activating factor (PAF), as PAF has already been shown to increase osteoclast activity.

RESULTS

In 5lo^-/- mice, there were no loss of alveolar bone and less TRAP-positive osteoclasts in periodontal tissues, after Aa inoculation, despite local production of TNF-α and IL-6. The differentiation and activity of osteoclasts stimulated with AaLPS were diminished in the presence of BLT1 antagonist or 5-LO inhibitor, but not in the presence of cysteinyl leukotriene receptor antagonist. The osteoclast differentiation induced by PAF was impaired by the BLT1 antagonism.

CONCLUSION

In conclusion, LTB4 but not CysLTs is important for Aa-induced alveolar bone loss. Overall, LTB4 affects osteoclast differentiation and activity and is a key intermediate of PAF-induced osteoclastogenesis.

Effect of erythritol on microbial ecology of in vitro gingivitis biofilms

Gingivitis is one of the most common oral infections in humans. While sugar alcohols such as erythritol are suggested to have caries-preventive properties, it may also have beneficial effects in prevention of gingivitis by preventing maturation of oral biofilms. The aim of this study was to assess the effect of erythritol on the microbial ecology and the gingivitis phenotype of oral microcosms. Biofilms were inoculated with stimulated saliva from 20 healthy donors and grown in a gingivitis model in the continuous presence of 0 (control group), 5, and 10% erythritol. After 9 days of growth, biofilm formation, protease activity (gingivitis phenotype), and microbial profile analyses were performed. Biofilm growth was significantly reduced in the presence of erythritol, and this effect was dose dependent. Protease activity and the Shannon diversity index of the microbial profiles of the biofilms were significantly lower when erythritol was present. Microbial profile analysis revealed that presence of erythritol induced a compositional shift from periodontitis- and gingivitis-related taxa toward early colonizers. The results of this study suggest that erythritol suppresses maturation of the biofilms toward unhealthy composition. The gingivitis phenotype was suppressed and biofilm formation was reduced in the presence of erythritol. Therefore, it is concluded that erythritol may contribute to a healthy oral ecosystem in vitro.

Association Study of Vitamin D Receptor (VDR) - Related Genetic Polymorphisms and their Haplotypes with Chronic Periodontitis in Colombian Population

INTRODUCTION

There is strong evidence that both genetic and environmental factors may affect the periodontal clinical status. However, epidemiological evidence on the association between Vitamin D Receptor (VDR) polymorphisms and Chronic Periodontitis (CP) has been inconsistent.

AIM

The focus of this study was to identify if a possible association between VDR Single-Nucleotide Polymorphisms (SNPs) may be implicated in the aetiopathogenesis of CP in Colombian population.

MATERIALS AND METHODS

One hundred and ten CP patients and 50 Healthy Controls (HC) were recruited. Periodontal status was assessed based on probing depth, clinical attachment level, extent, and severity of periodontal breakdown. The polymerase chain reaction-restriction fragment length polymorphism method was used to identify the VDR rs7975232, rs1544410, rs2228570, and rs731236 SNPs from saliva samples. Odds Ratios (ORs) along with their 95% Confidence Intervals (CIs) were computed to compare the distribution of genotypes/alleles between HC and CP patients, alongside with analysis of Linkage Disequilibrium (LD) and haplotype associations between SNPs. Also, an analysis of the interaction between genetic findings and those significant demographic factors was performed for all SNPs.

RESULTS

There was no association neither between the different genotypes/allele frequencies nor haplotypes and CP. Similarly, no significant differences in extent or severity amongst genotype/allele groups were observed. Even so, interaction analysis revealed significant synergistic interactions between each SNP and age associated with the disease status.

CONCLUSION

Although these results do not support that VDR SNPs could be identified as independent risk predictor variables for CP in the Colombian population, synergistic biological interactive effects of all these SNPs related to age might play a significant role in the pathogenic pathways of CP.

Expression of matrix metalloproteinases-2, -9 and reversion-inducing cysteine-rich protein with Kazal motifs in gingiva in periodontal health and disease

BACKGROUND AND OBJECTIVE

Periodontitis is characterized by pathological destruction of extracellular matrix (ECM) of periodontal tissues. Matrix metalloproteinases (MMPs) promote the occurrence and development of periodontitis by degrading almost all proteins of ECM. RECK (reversion-inducing-cysteine-rich protein with kazal motifs), a novel membrane-anchored inhibitor of MMPs, could regulate the expression of MMP-2 and MMP-9 at post-transcriptional level. The study was to investigate the expression of RECK in healthy and diseased human gingival tissues and to correlate it with the production of MMP-2 and MMP-9.

MATERIAL AND METHODS

Gingival biopsies were collected from chronic periodontitis patients and periodontally healthy control individuals. The protein and mRNA of RECK, MMP-2 and MMP-9 was determined by immunohistochemistry and semi-quantitative polymerase chain reaction analysis.

RESULTS

The expression of RECK protein was mainly confined to the gingival epithelium in inflamed and non-inflamed gingival tissues. Expression of RECK was significantly lower in tissues from chronic periodontitis patients, while the positive expression levels of MMP-2 and MMP-9 in periodontitis specimens were significantly higher. RECK protein expression was negatively correlated to the expressions of MMP-2 and MMP-9 in periodontitis. Moreover, RECK mRNA was significanly lower in diseased gingiva than in healthy samples(P<0.05), while MMP-2 and MMP-9 mRNAs were observed overexpressed in periodontal lesions, with no significant correlation between RECK and MMP-2/MMP-9 mRNA shown in periodontally diseased group.

CONCLUSION

The expression of RECK in human healthy and diseased gingiva may contribute to periodontal physiological and pathological processes; low RECK expression may be associated with the enhanced MMP-2 and MMP-9 production in inflamed gingiva.

Bioactive Polymeric Nanoparticles for Periodontal Therapy

Aims

to design calcium and zinc-loaded bioactive and cytocompatible nanoparticles for the treatment of periodontal disease.

Methods

PolymP-nActive nanoparticles were zinc or calcium loaded. Biomimetic calcium phosphate precipitation on polymeric particles was assessed after 7 days immersion in simulated body fluid, by scanning electron microscopy attached to an energy dispersive analysis system. Amorphous mineral deposition was probed by X-ray diffraction. Cell viability analysis was performed using oral mucosa fibroblasts by: 1) quantifying the liberated deoxyribonucleic acid from dead cells, 2) detecting the amount of lactate dehydrogenase enzyme released by cells with damaged membranes, and 3) by examining the cytoplasmic esterase function and cell membranes integrity with a fluorescence-based method using the Live/Dead commercial kit. Data were analyzed by Kruskal-Wallis and Mann-Whitney tests.

Results

Precipitation of calcium and phosphate on the nanoparticles surfaces was observed in calcium-loaded nanoparticles. Non-loaded nanoparticles were found to be non-toxic in all the assays, calcium and zinc-loaded particles presented a dose dependent but very low cytotoxic effect.

Conclusions

The ability of calcium-loaded nanoparticles to promote precipitation of calcium phosphate deposits, together with their observed non-toxicity may offer new strategies for periodontal disease treatment.

Novel strategy to detect and locate periodontal pathogens: The PNA-FISH technique

PURPOSE

We aim to develop peptic nucleic acid (PNA) probes for the identification and localization of Aggregatibacter actinomycetemcomintans and Porphyromonas gingivalis in sub-gingival plaque and gingival biopsies by Fluorescence in situ Hybridization (FISH).

METHODS

A PNA probe was designed for each microorganism. The PNA-FISH method was optimized to allow simultaneous hybridization of both microorganisms with their probe (PNA-FISH multiplex). After being tested on representative strains of P. gingivalis and A. actinomycetemcomitans, the PNA-FISH method was then adapted to detect microorganisms in the subgingival plaque and gingival samples, collected from patients with severe periodontitis.

RESULTS

The best hybridization conditions were found to be 59°C for 150min for both probes (PgPNA1007 and AaPNA235). The in silico sensitivity and specificity was both 100% for PgPNA1007 probe and 100% and 99.9% for AaPNA235 probe, respectively. Results on clinical samples showed that the PNA-FISH method was able to detect and discriminate target bacteria in the mixed microbial population of the subgingival plaque and within periodontal tissues.

CONCLUSION

This investigation presents a new highly accurate method for P. gingivalis and A. actinomycetemcomitans detection and co-location in clinical samples, in just few hours. With this technique we were able to observe spatial distribution of these species within polymicrobial communities in the periodontal pockets and, for the first time with the FISH method, in the organized gingival tissue.

Bacterial Viability within Dental Calculus: An Untrodden, Inquisitive Clinico-Patho- Microbiological Research

INTRODUCTION

Chronic inflammatory periodontal diseases i.e. gingivitis and periodontitis are one of the most common afflictions faced by human beings. Dental plaque, which is a pool of pathogenic microorganisms, remains to be current mainstay in etiopathogenesis. Dental calculus, which is a mineralized product of this plaque remains ignored and is considered merely as an ash heap of minor significance. However, the intriguing array in disease etiopathogenesis bulldozed researchers to suspect the role of calculus in disease chrysalis but still the viability of bacteria inside calculus and thus its pathogenicity remains an intricacy; the answer to which lies in the Pandora's Box.

AIM

The present study was undertaken to investigate the viability of bacteria within dental calculus along with their identification. Also, to classify dental calculus on the basis of mineralization and to observe the variation of viable microflora found in dental calculus with the extent of mineralization and disease severity.

MATERIALS AND METHODS

A total of 60 samples were obtained, by harvesting two samples of supragingival calculus from each patient having chronic inflammatory periodontal disease. These samples were divided into two groups (Group A and Group B). Samples of Group A were kept non-irradiated and samples of Group B were exposed to UV radiation. The samples were categorized into less, moderately and highly mineralized according to the force required for crushing them. All the crushed calculus samples were then divided into three parts. These were used for dark-field microscopy, gram staining and bacterial cultures. Bacterial identification of the cultures obtained was also carried out by performing various biochemical assays.

RESULTS

The present study revealed the presence of motile spirochaetes within the samples under dark-field microscope. Gram staining revealed presence of numerous gram positive cocci and gram negative bacilli. Bacterial cultures showed growth of variety of aerobic and capnophilic microorganisms.

CONCLUSION

The present study concludes the presence of viable aerobic and capnophilic bacteria inside dental calculus which may reside within the lacunae and channels in the calculus.

Favourable effects of Bacillus subtilis and Bacillus licheniformis on experimental periodontitis in rats

OBJECTIVES

The purposes of this study were to evaluate, in rats: i) the effects of Bacillus species on the development of experimental periodontitis (EP) via microtomographic, immunological and hematological assays (Experiment 1-E1); ii) the effects of Bacillus species as adjuncts to scaling and root planing (SRP) for the treatment of EP via histomorphometric and immunohistochemical analyses (Experiment 2-E2).

METHODS

In E1, 24 rats were divided into groups C1 (control), PROB1, EP1 and EP-PROB1. In groups with EP, the mandibular first molar of each animal received a ligature for 14 days. In groups PROB1, animals received Bacillus species for 44 days, starting 30 days before EP induction in Group EP-PROB1. In E2, 24 rats were assigned to groups C2 (control), PROB2, EP-SRP2 and EP-SRP-PROB2. In groups with SRP, EP was induced as described in E1. The ligatures were removed after 14 days and SRP was performed. In groups PROB2, animals received Bacillus species for 15 days, starting after SRP in Group EP-SRP-PROB2.

RESULTS

In E1, Group EP1 presented bone loss (BL) and eosinophil numbers greater than Group EP-PROB1 (P<0.05). In Group EP-PROB1, the receptor activator of nuclear factor-kB ligand (RANKL)/osteoprotegerin (OPG) ratio was similar to that of groups without EP. In E2, Group EP-SRP-PROB2 presented fewer TRAP-positive osteoclasts, lower immunolabeling pattern for a proinflammatory cytokine and decreased BL and attachment loss than Group EP-SRP2 (P<0.05).

CONCLUSIONS

Bacillus species supplementation provided a protective effect against BL and enhanced the effects of SRP in the treatment of EP in rats.

Transcriptome analysis reveals mucin 4 to be highly associated with periodontitis and identifies pleckstrin as a link to systemic diseases

The multifactorial chronic inflammatory disease periodontitis, which is characterized by destruction of tooth-supporting tissues, has also been implicated as a risk factor for various systemic diseases. Although periodontitis has been studied extensively, neither disease-specific biomarkers nor therapeutic targets have been identified, nor its link with systemic diseases. Here, we analyzed the global transcriptome of periodontitis and compared its gene expression profile with those of other inflammatory conditions, including cardiovascular disease (CVD), rheumatoid arthritis (RA), and ulcerative colitis (UC). Gingival biopsies from 62 patients with periodontitis and 62 healthy subjects were subjected to RNA sequencing. The up-regulated genes in periodontitis were related to inflammation, wounding and defense response, and apoptosis, whereas down-regulated genes were related to extracellular matrix organization and structural support. The most highly up-regulated gene was mucin 4 (MUC4), and its protein product was confirmed to be over-expressed in periodontitis. When comparing the expression profile of periodontitis with other inflammatory diseases, several gene ontology categories, including inflammatory response, cell death, cell motion, and homeostatic processes, were identified as common to all diseases. Only one gene, pleckstrin (PLEK), was significantly overexpressed in periodontitis, CVD, RA, and UC, implicating this gene as an important networking link between these chronic inflammatory diseases.

Possible evidence of systemic lupus erythematosus and periodontal disease association mediated by Toll-like receptors 2 and 4

Toll-like receptors (TLRs) participate in the innate immune response and trigger the immune responses of the body. Systemic lupus erythematosus (SLE) is an autoimmune disease of unknown aetiology, characterized by an excessive autoimmune response in the body affecting the connective tissues. The disease is possibly triggered by both environmental aetiological factors and pathological organic processes such as exposure to sunlight, chronic infectious processes and genetic factors. Conversely, periodontal disease is an infectious disease caused by microorganisms in the oral cavity, resulting in a chronic inflammatory process which continuously stimulates the immune response, thus causing damage to the periodontal tissues. The expression of both TLR-2 and TLR-4 receptors are increased in both SLE and periodontal disease. Periodontitis might trigger excessive activation of immune response occurring in SLE by maintaining a high expression of TLRs, leading in turn to the acceleration of the onset and progression of autoimmune reactions. In addition, periodontal treatment is able to reduce the expression of these receptors and therefore the symptoms of SLE. Here we discuss the possible interaction between SLE and periodontitis, and suggest further studies evaluating common features in both factors that could explored, due to morbidity and mortality of SLE and the high incidence of periodontal infections around the world.

Mini but mighty: microRNAs in the pathobiology of periodontal disease

MicroRNAs (miRNAs) are a family of small, noncoding RNA molecules that negatively regulate protein expression either by inhibiting initiation of the translation of mRNA or by inducing the degradation of mRNA molecules. Accumulating evidence suggests that miRNA-mediated repression of protein expression is of paramount importance in a broad range of physiologic and pathologic conditions. In particular, miRNA-induced dysregulation of molecular processes involved in inflammatory pathways has been shown to contribute to the development of chronic inflammatory diseases. In this review, first of all we provide an overview of miRNA biogenesis, the main mechanisms of action and the miRNA profiling tools currently available. Then, we summarize the available evidence supporting a specific role for miRNAs in the pathobiology of periodontitis. Based on a review of available data on the differential expression of miRNAs in gingival tissues in states of periodontal health and disease, we address specific roles for miRNAs in molecular and cellular pathways causally linked to periodontitis. Our review points to several lines of evidence suggesting the involvement of miRNAs in periodontal tissue homeostasis and pathology. Although the intricate regulatory networks affected by miRNA function are still incompletely mapped, further utilization of systems biology tools is expected to enhance our understanding of the pathobiology of periodontitis.

The role of toll-like and protease-activated receptors in the expression of cytokines by gingival fibroblasts stimulated with the periodontal pathogen Porphyromonas gingivalis

Porphyromonas gingivalis is a periodontitis-associated pathogen and interactions between the bacterium and gingival fibroblasts play an important role in development and progression of periodontitis, an inflammatory disease leading to degeneration of tooth-supporting structures. Gingival fibroblasts, which expresses protease activated receptors (PARs) as well as toll-like receptors (TLRs), produces inflammatory mediators upon bacterial challenges. In this study, we elucidated the importance of PAR1, PAR2, TLR2 and TLR4 for the expression and secretion of CXCL8, interleukin-6 (IL-6), transforming growth factor-β1 (TGF-β1) and secretory leukocyte inhibitor (SLPI). Human gingival fibroblasts were transfected with small-interfering RNA against the target genes, and then stimulated with P. gingivalis wild-type W50 and W50-derived double rgp mutant E8 and kgp mutant K1A. TLR2-silencing reduced P. gingivalis-induced CXCL8 and IL-6. IL-6 was also reduced after PAR1-silencing. No effects were observed for TGF-β1. SLPI was suppressed by P. gingivalis and silencing of PAR1 as well as TLR2, gave additional suppression at the mRNA level. TLR4 was not involved in the regulation of the investigated mediators. CXCL8 and IL-6 are important for progression and development of periodontitis, leading to a chronic inflammation that may contribute to the tissue destruction that follows an exacerbated host response. Therefore, regulating the expression of TLR2 and subsequent release of CXCL8 and IL-6 in periodontitis could attenuate the tissue destruction seen in periodontitis.

Effect of application of a PVP-iodine solution before and during subgingival ultrasonic instrumentation on post-treatment bacteraemia: a randomized single-centre placebo-controlled clinical trial

BACKGROUND

To assess the effect of concomitant subgingival rinsing with 10% PVP-iodine during subgingival instrumentation on the prevalence and magnitude of bacteraemia of oral origin.

MATERIALS AND METHODS

Subgingival instrumentation was performed with water or PVP-iodine rinse in patients with periodontitis. Prior to instrumentation, subjects gargled for 1 min with the allocated liquid. Pockets were then rinsed for 1 min and subgingivally instrumented with liquid-cooled (water/PVP-iodine) ultrasonic scalers (1 min). Two minutes later, a blood sample from the arm vein was drawn using a lysis centrifugation blood culture system for quantitative microbiological analysis. Non-parametric statistical tests were performed to assess differences in the prevalence and extent of bacteraemia between groups.

RESULTS

Of the 19 samples in each group, oral-borne bacteraemia was detected in 10 of the control and 2 of the test samples. With an average of 3.0 [1; 5] colony forming units, significantly less bacteria and bacteraemia were found in the test group compared to the controls (12.2 [1; 46]) (p = 0.003). Anaerobic bacteria were not found in the test group.

CONCLUSIONS

Bacteraemia after subgingival instrumentation with concomitant PVP-iodine rinsing is reduced but not eliminated. Therefore, it might be recommended for patients at a high risk of endocarditis or infection of endoprostheses. However, preventive antibiotic treatment should not be omitted.

Bacterial profile of aggressive periodontitis in Morocco: a cross-sectional study

Background

Aggressive periodontitis (AgP) is one of the most severe forms of periodontal diseases. In Morocco, Aggregatibacter actinomycetemcomitans has been strongly associated with AgP, however limited knowledge is available about the implication of other periodontal pathogens in this entity. Therefore, the main aim of this study was to evaluate the composition of the subgingival microbiota in Moroccan patients with AgP.

Methods

Subgingival plaque samples were collected from 50 aggressive, 13 localized and 37 generalized periodontitis patients. Samples from 20 chronic periodontitis (ChP) patients were taken as controls. Samples collected from the four deepest periodontal pockets in each patient were pooled in pre-reduced transport fluid and examined by culture.

Results

A. actinomycetemcomitans was significantly more frequent (p = 0.004) in generalised AgP compared to ChP, and Porphyromonas gingivalis was less prevalent in localized AgP, when compared with generalized AgP (p = 0.040) or ChP (p = 0.016). Prevotella intermedia, Fusobacterium nucleatum and Tannerella forsythia were also frequently detected in all groups. Mean proportions of A. actinomycetemcomitans were significantly higher in AgP groups, when compared to ChP, and generalized AgP patients harbored significantly higher proportions of P. gingivalis and T. forsythia, when compared to localized AgP or ChP.

Conclusions

A. actinomycetemcomitans, P. gingivalis, T. forsythia, P. intermedia and F. nucleatum were frequently detected in this Moroccan population with AgP. Differences in frequency of detection, counts and proportions of A. actinomycetemcomitans, P. gingivalis and T. forsythia suggests the presence of distinct microbiological profiles for localized AgP, generalized AgP and ChP patients.