Periodontitis in young individuals: Important factors for disease progression.

AIM: To investigate the progression of periodontitis in young individuals and identify factors that contribute to progression rate and whether periodontitis stage and grade have an impact on disease progression. MATERIALS AND METHODS: This retrospective cohort study was based on patients younger than 36 years at two periodontal clinics between 2003 and 2009. At least 10 years later, a clinical and radiographic examination was performed on 215 patients. The marginal bone loss between baseline and follow-up for the tooth with the most severe bone loss at follow-up was estimated by radiographic measurements. Linear regression analysis was used to investigate the influence of potential risk indicators on periodontitis progression. RESULTS: Most patients (83%) were classified as periodontitis stage III at baseline. At follow-up, 70% of these patients remained in stage III. The frequency of patients with grade C decreased from 79% to 17% at follow-up. The median (Q25%; Q75%) of the longitudinal marginal bone loss was 0.5 mm (0.0; 2.0). High bleeding on probing (BOP) index at baseline, smoking and interruption of periodontal treatment were found to significantly increase longitudinal bone loss. CONCLUSIONS: High levels of BOP at baseline, smoking and interruption of periodontal treatment increased the risk of marginal bone loss. The stage and grade at baseline had no significant impact on disease progression.

Observational study of selective screening for prediabetes and diabetes in a real-world setting: an interprofessional collaboration method between public dental services and primary health care in Sweden.

OBJECTIVE: Describe a method in a real-world setting to identify persons with undiagnosed prediabetes and type 2 diabetes through an interprofessional collaboration between Public Dental Services and Primary Health Care in Regions Stockholm. DESIGN: A descriptive observational study. SETTING: The study was conducted at seven sites in the region of Stockholm, Sweden. Each collaborating site consisted of a primary health clinic and dental clinic. SUBJECTS: Study participants included adults over 18 years of age who visited the Public Dental Services and did not have a medical history of prediabetes or type 2 diabetes. MAIN OUTCOME MEASURES: Selective screening is conducted in accordance with a risk assessment protocol at the Public Dental Services. In the investigated method, DentDi (Dental and Diabetes), adults diagnosed with caries and/or periodontitis over a cut-off value are referred to the Primary Health Care clinic for screening of prediabetes and type 2 diabetes. RESULTS: DentDi, introduced at seven sites, between the years 2017 and 2020, all of which continue to use the method today. A total of 863 participants from the Public Dental Services were referred to the Primary Health Care. Of those 396 accepted the invitation to undergo screening at the primary health care centre. Twenty-four individuals did not meet the inclusion criteria, resulting in a total of 372 persons being included in the study. Among the 372 participants, 27% (101) had elevated glucose levels, of which 12 were diagnosed with type 2 diabetes and 89 with prediabetes according to the study classification. CONCLUSIONS: DentDi is a feasible method of interprofessional collaboration where each profession contributes with the competence included in everyday clinical practice for early identification of persons with prediabetes and type 2 diabetes with a complete chain of care. The goal is to disseminate this method throughout Stockholm County and even other regions in Sweden.

Type 2 diabetes and poor oral health have a bidirectional association. The number of persons with undetected prediabetes and type 2 diabetes is high and rising globally.Through collaboration between Public Dental Services and Primary Health Care we have developed a feasible and novel method of selectively screening for prediabetes and type 2 diabetes in a real-world setting.By utilizing everyday practice within each discipline, this method has been implemented at seven sites in Region Stockholm.From the original number of 863 participants referred from the Public Dental Services to Primary Health Care 396 attended the medical screening. After excluding 24 participants, a total of 372 participants underwent screening for prediabetes and type 2 diabetes.The results of this study showed that almost 30% who were screened for prediabetes and type 2 diabetes had elevated blood glucose levels.

Periodontal microorganisms and diagnosis of malignancy: A cross-sectional study.

BACKGROUND: Oral infections associate statistically with cancer. OBJECTIVE: We hypothesized that certain periodontal microorganisms might specifically link to malignancies in general and set out to investigate this in our ongoing cohort study. METHODS: A sample of 99 clinically examined patients from our cohort of 1676 subjects was used to statistically investigate the associations between harboring periodontal microorganisms Aggregatibacter actinomycetemcomitans (A.a), Porphyromonas gingivalis (P.g), Prevotella intermedia (P.i), Tannerella forsythia (T.f) and Treponema denticola (T.d). We used oral infection indexes and the incidence figures of malignancies as registered in 2008-2016 in the Swedish National Cancer Register. RESULTS: The pathogen A.a showed strong association with malignancy in 32 out of the 99 patients while P.g and P.i were more prevalent among patients without malignancy. In principal component analyses, A.a appeared in the strongest component while the second strongest component consisted of a combination of T.f and T.d. The third component consisted of a combination of P.g and P.i, respectively. Of basic and oral health variables, gingival index appeared to be the strongest expression of inflammation (Eigen value 4.11 and Explained Variance 68.44 percent). CONCLUSIONS: The results partly confirmed our hypothesis by showing that harboring certain periodontal bacteria might link to malignancy. However, the associations are statistical and no conclusions can be drawn about causality.

Intra-individual cytokine profile in peri-implantitis and periodontitis: A cross-sectional study.

AIM: To study cytokine profiles and intra-individual correlations in crevicular fluid samples at periodontitis, peri-implantitis, and healthy sites. MATERIALS AND METHODS: Samples from gingival crevicular fluid (GCF) and peri-implant crevicular fluid (PICF) were collected from healthy and diseased sites in patients who had had dental implants for a minimum of 10 years. Cytokine levels were analyzed using the Bio-Plex Pro Human inflammation kit, which included biomarkers for the tumor necrosis factor-α (TNF-α) superfamily, regulatory T Cell (Treg) cytokines, and interferon (IFN) proteins. RESULTS: Gingival crevicular fluid/PICF cytokine levels, determined in samples from 163 patients, were frequently lower for healthy tooth and implant sites compared to sites with periodontitis or peri-implantitis. In contrast, there were no significant differences in cytokine levels between peri-implant sites and periodontitis sites. Intra-individual correlations between cytokines at peri-implant sites were frequently significant. In addition, the cytokines IFN-λ1 and TNFSF12 were significantly correlated with the presence of peri-implantitis. CONCLUSION: Within the limits of this study, the intra-individual cytokine profile did not differ between sites diagnosed with periodontitis and those diagnosed with peri-implantitis, but did differ between healthy tooth and healthy implant sites. Studying intra-individual cytokine profiles is a method to elucidate possible differences between the etiopathogeneses of periodontitis and peri-implantitis, since it is well known that immune responses to dysbiosis vary between individuals according to host factors. Thus, the findings of the present study are potentially relevant to the advancement of knowledge in this field.

Treponema denticola chymotrypsin-like proteinase may contribute to orodigestive carcinogenesis through immunomodulation.

BACKGROUND: Periodontal pathogens have been linked to oral and gastrointestinal (orodigestive) carcinogenesis. However, the exact mechanisms remain unknown. Treponema denticola (Td) is associated with severe periodontitis, a chronic inflammatory disease leading to tooth loss. The anaerobic spirochete Td is an invasive bacteria due to its major virulence factor chymotrypsin-like proteinase. Here we aimed to investigate the presence of Td chymotrypsin-like proteinase (Td-CTLP) in major orodigestive tumours and to elucidate potential mechanisms for Td to contribute to carcinogenesis. METHODS: The presence of Td-CTLP within orodigestive tumour tissues was examined using immunohistochemistry. Oral, tonsillar, and oesophageal squamous cell carcinomas, alongside gastric, pancreatic, and colon adenocarcinomas were stained with a Td-CTLP-specific antibody. Gingival tissue from periodontitis patients served as positive controls. SDS-PAGE and immunoblot were used to analyse the immumodulatory activity of Td-CTLP in vitro. RESULTS: Td-CTLP was present in majority of orodigestive tumour samples. Td-CTLP was found to convert pro MMP-8 and -9 into their active forms. In addition, Td-CTLP was able to degrade the proteinase inhibitors TIMP-1, TIMP-2, and α-1-antichymotrypsin, as well as complement C1q. CONCLUSIONS: Because of its presence within tumours and regulatory activity on proteins critical for the regulation of tumour microenvironment and inflammation, the Td-CTLP may contribute to orodigestive carcinogenesis.

Increased citrullination and expression of peptidylarginine deiminases independently of P. gingivalis and A. actinomycetemcomitans in gingival tissue of patients with periodontitis.

BACKGROUND: A relationship between rheumatoid arthritis (RA) and periodontitis has been suggested from findings that individuals with RA are prone to have advanced periodontitis and vice versa. In search of possible common pathogenetic features of these two diseases, we investigated the presence of citrullinated proteins and expression of endogenous peptidylarginine deiminases (PAD2 and PAD4), in periodontal tissue of individuals with periodontitis and healthy controls, in relation to the periodontal pathogens Porphyromonas gingivalis (P. gingivalis) and Aggregatibacter actinomycetemcomitans (A. actinomycetemcomitans), producing leukotoxin as virulence factor. These two oral bacteria have been suggested to be linked to anti-citrullinated protein antibodies in patients with RA. METHODS: Gingival tissue biopsies were obtained from 15 patients with periodontitis and 15 individuals without periodontal disease. Presence of CD3-positive lymphocytes, citrullinated proteins, PAD2, PAD4, P. gingivalis as well as A. actinomycetemcomitans and Mannheimia haemolytica produced leukotoxins were analysed by immunohistochemistry, followed by triple-blind semi-quantitative analysis. Mann-Whitney and Fisher's exact tests were used to analyse differences between groups. PADI2 and PADI4 mRNA levels were assessed by RT-qPCR and analysed using Wilcoxon signed rank test. RESULTS: Increased staining of citrullinated proteins was observed in gingival connective tissue from subjects with periodontitis (80%, 12/15) compared to healthy gingival tissue (27%, 4/15), whereas no differences were observed in gingival epithelium. There was also an increased staining of the citrullinating enzymes PAD2 and PAD4 in gingival connective tissue of patients with periodontitis whereas similar levels of PAD2 and PAD4 were observed in the gingival epithelium of the two groups. Similarly, the mRNA levels of PADI2 and PADI4 were also increased in the gingival tissue of patients with periodontitis compared to healthy controls. Furthermore, presence of P. gingivalis and leukotoxins was comparable in both epithelium and connective tissue, from the different investigated individuals with and without periodontitis, and there were no correlations between the presence of periodontal pathogens and the expression of citrullinated proteins or PAD enzymes. CONCLUSION: Chronic gingival inflammation is associated with increased local citrullination and PAD2 and PAD4 expression in periodontitis. The increased citrullination and PAD2 and PAD4 expression in periodontitis were, however, independent of the presence of periodontal pathogen P. gingivalis and A. actinomycetemcomitans leukotoxin.

Treponema denticola chymotrypsin-like proteinase is present in early-stage mobile tongue squamous cell carcinoma and related to the clinicopathological features.

BACKGROUND: Certain periodontopathogenic bacteria have been linked to cancers. Treponema denticola (Td) is associated with severe periodontitis. Chymotrypsin-like proteinase (CTLP), a major virulence factor of Td, can degrade various host proteins and peptides, and modulate inflammatory responses. However, the role of Td in the tongue carcinogenesis remains unknown. This study aimed to investigate the presence of Td-CTLP in early-stage mobile tongue squamous cell carcinoma (MTSCC) and its relation to clinical and pathological characteristics. METHODS: The immunopositivity of Td-CTLP was assessed in samples obtained from 60 patients with MTSCC and associated with their clinicopathological data. Additionally, Td-CTLP expression was compared with immunoexpression of matrix metalloproteinases (MMP-8 and MMP-9), toll-like receptors (TLR-2, TLR-4, TLR-7 and TLR-9), c-Myc, Ki-67, Bmi-1 and Snail. RESULTS: Treponema denticola-chymotrypsin-like proteinase was present in 95% of MTSCC tumours of which many (40.4%) showed high immunopositivity. Td-CTLP positivity was significantly associated with invasion depth, tumour diameter and the expression of TLR-7, TLR-9 and c-Myc. High Td-CTLP immunopositivity in younger patients (≤ 60 years old) predicted early relapse. CONCLUSION: Our data indicate that Td and its CTLP are present in early-stage MTSCC carcinoma and may contribute to carcinogenesis, and therefore provide novel perspectives into intervention and therapeutic measures of MTSCC.

Mucin 4 and matrix metalloproteinase 7 as novel salivary biomarkers for periodontitis.

AIM: Periodontitis is a chronic inflammatory disease, characterized by irreversible destruction of tooth-supporting tissue including alveolar bone. We recently reported mucin 4 (MUC4) and matrix metalloproteinase 7 (MMP7) as highly associated with periodontitis in gingival tissue biopsies. The aim of this study was to further investigate the levels of MUC4 and MMP7 in saliva and gingival crevicular fluid (GCF) samples of patients with periodontitis. MATERIALS AND METHODS: Saliva and GCF samples were collected from periodontitis patients and healthy controls. The levels of MUC4, MMP7, and total protein concentrations were analysed using ELISA or Bradford assay. RESULTS: MUC4 levels were significantly lower in saliva and GCF from periodontitis patients relative to healthy controls. MMP7 levels were significantly higher in saliva and GCF from periodontitis patients. Multivariate analysis revealed that MUC4 was significantly associated with periodontitis after adjusting for age and smoking habits and, moreover, that the combination of MUC4 and MMP7 accurately discriminated periodontitis from healthy controls. CONCLUSIONS: MUC4 and MMP7 may be utilized as possible novel biomarkers for periodontitis.

Effects of polyhexamethylene guanidine phosphate on human gingival fibroblasts.

OBJECTIVE: Polyhexamethylene guanidine phosphate (PHMG-P) was compared to chlorhexidine (CHX) in order to determine potential cytotoxic and immune-modulatory effects on human gingival fibroblasts. MATERIALS AND METHODS: Cytotoxic effects of PHMG-P and CHX on human gingival fibroblasts were assessed using cell viability assay at various time points and concentrations. The effects of PHMG-P and CHX on the secretion of prostaglandin (PG) E2, interleukin (IL)-6, IL-8 and matrix metalloproteinase (MMP)-1 by non-stimulated or IL-1ß stimulated fibroblasts were evaluated by enzyme-linked immunosorbent assays. RESULTS: PHMG-P concentration 0.00009% led to the total loss of fibroblast viability within 24 h, whereas inhibition of fibroblast viability by CHX occurred at significantly higher concentrations of 0.0009% (p < .001). Short-term exposure to 0.005% PHMG-P led to loss of fibroblast viability after 5 min, whilst cells exposed to 0.005% CHX survived 30 min of treatment (p < .001). IL-1ß stimulation induced an inflammatory response with a significant increase in the secretion of PGE2, IL-6, IL-8 and MMP-1. Treatment of IL-1ß stimulated fibroblasts in combination with PHMG-P or CHX at concentrations of 0.000045 or 0.0.00009% resulted in significantly decreased PGE2, IL-6, IL-8 and MMP-1 levels. PHMG-P or CHX alone did not affect the baseline secretion of PGE2, IL-6, IL-8 or MMP-1 by gingival fibroblasts. CONCLUSIONS: Cytotoxic effects on gingival fibroblasts were triggered by both PHMG-P and CHX at concentrations below those used in clinical practice. The tested antiseptics did not cause inflammation and reduced IL-1ß-induced secretion of inflammatory mediators and collagenase by gingival fibroblasts, which suggests anti-inflammatory properties.

Effects by periodontitis on pristane-induced arthritis in rats.

BACKGROUND: An infection-immune association of periodontal disease with rheumatoid arthritis has been suggested. This study aimed to investigate the effect of pre-existing periodontitis on the development and the immune/inflammatory response of pristane-induced arthritis. METHODS: We investigated the effect of periodontitis induced by ligature placement and Porphyromonas gingivalis (P. gingivalis) infection, in combination with Fusobacterium nucleatum to promote its colonization, on the development of pristane-induced arthritis (PIA) in rats (Dark Agouti). Disease progression and severity of periodontitis and arthritis was monitored using clinical assessment, micro-computed tomography (micro-CT)/intraoral radiographs, antibody response, the inflammatory markers such as α-1-acid glycoprotein (α-1-AGP) and c-reactive protein (CRP) as well as cytokine multiplex profiling at different time intervals after induction. RESULTS: Experimentally induced periodontitis manifested clinically (P < 0.05) prior to pristane injection and progressed steadily until the end of experiments (15 weeks), as compared to the non-ligated arthritis group. Injection of pristane 8 weeks after periodontitis-induction led to severe arthritis in all rats demonstrating that the severity of arthritis was not affected by the pre-existence of periodontitis. Endpoint analysis showed that 89% of the periodontitis-affected animals were positive for antibodies against arginine gingipain B and furthermore, the plasma antibody levels to a citrullinated P. gingivalis peptidylarginine deiminase (PPAD) peptide (denoted CPP3) were significantly (P < 0.05) higher in periodontitis rats with PIA. Additionally, there was a trend towards increased pro-inflammatory and anti-inflammatory cytokine levels, and increased α-1-AGP levels in plasma from periodontitis-challenged PIA rats. CONCLUSIONS: Pre-existence of periodontitis induced antibodies against citrullinated peptide derived from PPAD in rats with PIA. However, there were no differences in the development or severity of PIA between periodontitis challenged and periodontitis free rats.

The relationship between oral mucositis and levels of pro-inflammatory cytokines in serum and in gingival crevicular fluid in allogeneic stem cell recipients.

PURPOSE: Oral mucositis (OM) is a severe side effect of conditioning for allogeneic hematopoietic stem cell transplantation (HSCT). The aim of the present study was to investigate the relationship between oral mucositis and the levels of pro-inflammatory cytokines-both in serum and in gingival crevicular fluid (GCF), in relation to different conditioning regimens. METHODS: We analyzed the levels of pro-inflammatory cytokines IL-1ß, TNF-α, IL-6, and IL-7, as well as anti-inflammatory cytokine IL-10 in gingival crevicular fluid (GCF) and in serum from 43 HSCT patients. Twenty-five received reduced intensity conditioning (RIC) and 18 received myeloablative conditioning (MAC). Cytokine levels were determined in GCF and serum before the start of conditioning, and 1 week and 1 month after HSCT. All patients experienced OM with a median score of 2.1 and median peak on day 11. RESULTS: There was a significant correlation between OM and MAC (p = 0.035). There were no significant differences in GCF volume at the three time points examined. The levels of IL-6 in GCF increased 1 week after transplantation and then returned to baseline (p < 0.001). The levels of IL-10 in GCF decreased after HSCT (p < 0.001) and remained unchanged. The levels of IL-6 in serum significantly (p < 0.001) increased 1 week after HSCT and decreased to baseline levels after 1 month. The levels of IL-10 in serum significantly (p = 0.02) increased 1 month after HSCT. CONCLUSION: No correlations between cytokine levels in gingival crevicular fluid and oral mucositis were observed. There was a correlation between severity of OM score and increase in IL-6 in serum. No correlations between cytokine levels in gingival crevicular fluid and in serum were observed.

Inhibition of microsomal prostaglandin E synthase-1 by aminothiazoles decreases prostaglandin E2 synthesis in vitro and ameliorates experimental periodontitis in vivo.

The potent inflammatory mediator prostaglandin E2 (PGE2) is implicated in the pathogenesis of several chronic inflammatory conditions, including periodontitis. The inducible enzyme microsomal prostaglandin E synthase-1 (mPGES-1), catalyzing the terminal step of PGE2 biosynthesis, is an attractive target for selective PGE2 inhibition. To identify mPGES-1 inhibitors, we investigated the effect of aminothiazoles on inflammation-induced PGE2 synthesis in vitro, using human gingival fibroblasts stimulated with the cytokine IL-1ß and a cell-free mPGES-1 activity assay, as well as on inflammation-induced bone resorption in vivo, using ligature-induced experimental periodontitis in Sprague-Dawley rats. Aminothiazoles 4-([4-(2-naphthyl)-1,3-thiazol-2-yl]amino)phenol (TH-848) and 4-(3-fluoro-4-methoxyphenyl)-N-(4-phenoxyphenyl)-1,3-thiazol-2-amine (TH-644) reduced IL-1ß-induced PGE2 production in fibroblasts (IC50 1.1 and 1.5 µM, respectively) as well as recombinant mPGES-1 activity, without affecting activity or expression of the upstream enzyme cyclooxygenase-2. In ligature-induced experimental periodontitis, alveolar bone loss, assessed by X-ray imaging, was reduced by 46% by local treatment with TH-848, compared to vehicle, without any systemic effects on PGE2, 6-keto PGF1α, LTB4 or cytokine levels. In summary, these results demonstrate that the aminothiazoles represent novel mPGES-1 inhibitors for inhibition of PGE2 production and reduction of bone resorption in experimental periodontitis, and may be used as potential anti-inflammatory drugs for treatment of chronic inflammatory diseases, including periodontitis.

Clinical and biological indicators of dental caries and periodontal disease in adolescents with or without obesity.

OBJECTIVE: This study aims to assess clinical, microbiological and inflammatory parameters as indicators for caries and periodontal disease in adolescents with obesity. MATERIAL AND METHODS: Twenty-seven adolescents with obesity [body mass index (BMI) 37 ± 4 kg/m(2)] and 28 controls (BMI 20 ± 2 kg/m(2)) answered questionnaires and were investigated regarding salivary parameters, plaque pH drop after a 1-min glucose rinse, oral clinical parameters, inflammatory markers in gingival crevicular fluid (GCF) and sub-gingival mirobiota. RESULTS: Compared with controls, adolescents with obesity had a lower stimulated salivary secretion rate (1.55 ± 0.63 vs. 2.05 ± 1.05 mL/min, p < 0.05), higher concentrations of secretory immunoglobulin A (sIgA) (p < 0.001), more decayed tooth surfaces (3.4 ± 6.6 vs. 0.8 ± 1.1, p < 0.05) and more gingivitis (p < 0.01) after controlling for possible confounders. Overall, similar snacking habits, plaque amounts and numbers of deep periodontal pockets were observed. Following the glucose rinse, a slightly more pronounced drop in plaque pH was observed in the obesity group (p > 0.05). No differences in sub-gingival inflammatory or microbial indicators were detected (p > 0.01). CONCLUSIONS: More caries and gingival inflammation were observed in adolescents with obesity. Of the indicators tested, salivary secretion rate was lower and sIgA levels were higher in the obesity group. We are unable to confirm whether differences in caries and gingival inflammation are due to systemic changes that are associated with obesity or due to possible irregular dietary/oral hygiene habits. CLINICAL RELEVANCE: Customised oral health preventive programmes and appropriate collaboration with medical personnel in selecting the best diet, medication and psychological support can help improve the general well-being, including oral health, of children with obesity. This may even reduce the risk of oral diseases.

Adherence of human oral keratinocytes and gingival fibroblasts to nano-structured titanium surfaces.

BACKGROUND: A key element for long-term success of dental implants is integration of the implant surface with the surrounding host tissues. Modification of titanium implant surfaces can enhance osteoblast activity but their effects on soft-tissue cells are unclear. Adherence of human keratinocytes and gingival fibroblasts to control commercially pure titanium (CpTi) and two surfaces prepared by anodic oxidation was therefore investigated. Since implant abutments are exposed to a bacteria-rich environment in vivo, the effect of oral bacteria on keratinocyte adhesion was also evaluated. METHODS: The surfaces were characterized using scanning electron microscopy (SEM). The number of adhered cells and binding strength, as well as vitality of fibroblasts and keratinocytes were evaluated using confocal scanning laser microscopy after staining with Live/Dead Baclight. To evaluate the effect of bacteria on adherence and vitality, keratinocytes were co-cultured with a four-species streptococcal consortium. RESULTS: SEM analysis showed the two anodically oxidized surfaces to be nano-structured with differing degrees of pore-density. Over 24 hours, both fibroblasts and keratinocytes adhered well to the nano-structured surfaces, although to a somewhat lesser degree than to CpTi (range 42-89% of the levels on CpTi). The strength of keratinocyte adhesion was greater than that of the fibroblasts but no differences in adhesion strength could be observed between the two nano-structured surfaces and the CpTi. The consortium of commensal streptococci markedly reduced keratinocyte adherence on all the surfaces as well as compromising membrane integrity of the adhered cells. CONCLUSION: Both the vitality and level of adherence of soft-tissue cells to the nano-structured surfaces was similar to that on CpTi. Co-culture with streptococci reduced the number of keratinocytes on all the surfaces to approximately the same level and caused cell damage, suggesting that commensal bacteria could affect adherence of soft-tissue cells to abutment surfaces in vivo.

In Vivo Regulation of Active Matrix Metalloproteinase-8 (aMMP-8) in Periodontitis: From Transcriptomics to Real-Time Online Diagnostics and Treatment Monitoring.

BACKGROUND: This study investigated in vivo regulation and levels of active matrix metalloproteinase-8 (aMMP-8), a major collagenolytic protease, in periodontitis. METHODS: Twenty-seven adults with chronic periodontitis (CP) and 30 periodontally healthy controls (HC) were enrolled in immunohistochemistry and transcriptomics analytics in order to assess Treponema denticola (Td) dentilisin and MMP-8 immunoexpression, mRNA expression of MMP-8 and its regulators (IL-1ß, MMP-2, MMP-7, TIMP-1). Furthermore, the periodontal anti-infective treatment effect was monitored by four different MMP-8 assays (aMMP-8-IFMA, aMMP-8-Oralyzer, MMP-8-activity [RFU/minute], and total MMP-8 by ELISA) among 12 CP (compared to 25 HC). RESULTS: Immunohistochemistry revealed significantly more Td-dentilisin and MMP-8 immunoreactivities in CP vs. HC. Transcriptomics revealed significantly elevated IL-1ß and MMP-7 RNA expressions, and MMP-2 RNA was slightly reduced. No significant differences were recorded in the relatively low or barely detectable levels of MMP-8 mRNAs. Periodontal treatment significantly decreased all MMP-8 assay levels accompanied by the assessed clinical indices (periodontal probing depths, bleeding-on-probing, and visual plaque levels). However, active but not total MMP-8 levels persisted higher in CP than in periodontally healthy controls. CONCLUSION: In periodontal health, there are low aMMP-8 levels. The presence of Td-dentilisin in CP gingivae is associated with elevated aMMP-8 levels, potentially contributing to a higher risk of active periodontal tissue collagenolysis and progression of periodontitis. This can be detected by aMMP-8-specific assays and online/real-time aMMP-8 chair-side testing.

Inflammatory mediators in the pathogenesis of periodontitis.

Periodontitis is a chronic inflammatory condition of the periodontium involving interactions between bacterial products, numerous cell populations and inflammatory mediators. It is generally accepted that periodontitis is initiated by complex and diverse microbial biofilms which form on the teeth, i.e. dental plaque. Substances released from this biofilm such as lipopolysaccharides, antigens and other virulence factors, gain access to the gingival tissue and initiate an inflammatory and immune response, leading to the activation of host defence cells. As a result of cellular activation, inflammatory mediators, including cytokines, chemokines, arachidonic acid metabolites and proteolytic enzymes collectively contribute to tissue destruction and bone resorption. This review summarises recent studies on the pathogenesis of periodontitis, with the main focus on inflammatory mediators and their role in periodontal disease.

Effect of probiotic lozenges on inflammatory reactions and oral biofilm during experimental gingivitis.

AIM: Probiotic bacteria have been introduced for prevention and treatment of periodontal diseases. The aim was to assess if daily oral administration of probiotic bacteria could influence the inflammatory response and the composition of supragingival plaque in an experimental gingivitis model. MATERIALS AND METHODS: Eighteen healthy female adults volunteered after informed consent. A double-blind randomized placebo-controlled cross-over design was used. The buccal surface of first molars was used as experimental sites. A mouth-guard covering the first premolar to second molar was used when brushing, preventing accidental cleaning during 3 weeks of plaque accumulation. Lozenges containing L. reuteri (ATCC55730 and ATCC PTA5289) or placebo were taken twice a day. During the run-in and washout periods, professional tooth cleaning was performed 5 days/week. At baseline and follow-up, plaque index, gingival index and bleeding on probing were recorded. Samples of gingival crevicular fluid (GCF) were analysed for concentration of seven inflammatory mediators. Bacterial samples were processed with checkerboard DNA/DNA-hybridization. RESULTS: All subjects presented a local plaque accumulation and developed manifest gingivitis at the test sites during the intervention periods. The volume of GCF increased in both groups but was statistically significant only in the placebo group (p < 0.05). The concentrations of IL1-ß and IL-18 increased significantly (p < 0.05), while IL-8 and MIP1-ß decreased (p < 0.05). No differences were displayed between test and placebo. Likewise, the microbial composition did not differ between the groups. CONCLUSION: Daily intake of probiotic lozenges did not seem to significantly affect the plaque accumulation, inflammatory reaction or the composition of the biofilm during experimental gingivitis.

Composition of subgingival microbiota associated with periodontitis and diagnosis of malignancy-a cross-sectional study.

Periodontitis is one of the world's most prevalent infectious conditions, affecting between 25 and 40% of the adult population. It is a consequence of the complex interactions between periodontal pathogens and their products, which trigger the host inflammatory response, chronic inflammation, and tissue destruction. Chronic systemic low-grade inflammation is involved in numerous diseases, and it is also known that long-lasting inflammation and chronic infections predispose one to cancer. Here, we characterized and compared the subgingival microbiota associated with periodontitis and diagnosis of malignancy in a longitudinal 10-year follow-up study. The study was conducted on 50 patients with periodontitis and 40 periodontally healthy individuals. The recorded clinical oral health parameters were periodontal attachment loss (AL), bleeding on probing (BOP), gingival index (GI), probing depth (PD), and plaque index (PI). Subgingival plaque was collected from each participant, from which DNA was extracted, and 16S rRNA gene amplicon sequencing performed. Cancer diagnoses data were collected between the years 2008-2018 from the Swedish Cancer Registry. The participants were categorized based on having cancer at the time of sample collection (CSC), having developed cancer later (DCL), and controls without any cancer. The most abundant phyla across all 90 samples were Actinobacteria, Proteobacteria, Firmicutes, Bacteroidetes, and Fusobacteria. At the genus level, Treponema, Fretibacterium, and Prevotella were significantly more abundant in samples of periodontitis patients compared to non-periodontitis individuals. With regard to samples of cancer patients, Corynebacterium and Streptococcus were more abundant in the CSC group; Prevotella were more abundant in the DCL group; and Rothia, Neisseria, and Capnocytophaga were more abundant in the control group. In the CSC group, we also found that the presence of periodontal inflammation, in terms of BOP, GI, and PLI, significantly correlated with species belonging to the genera Prevotella, Treponema, and Mycoplasma. Our results revealed that several subgingival genera were differentially enriched among the studied groups. These findings underscore the need for further research to fully understand the role that oral pathogens may play in the development of cancer.

Expression of prostaglandin E synthases in periodontitis immunolocalization and cellular regulation.

The inflammatory mediator prostaglandin E(2) (PGE(2)) is implicated in the pathogenesis of chronic inflammatory diseases including periodontitis; it is synthesized by cyclooxygenases (COX) and the prostaglandin E synthases mPGES-1, mPGES-2, and cPGES. The distribution of PGES in gingival tissue of patients with periodontitis and the contribution of these enzymes to inflammation-induced PGE(2) synthesis in different cell types was investigated. In gingival biopsies, positive staining for PGES was observed in fibroblasts and endothelial, smooth muscle, epithelial, and immune cells. To further explore the contribution of PGES to inflammation-induced PGE(2) production, in vitro cell culture experiments were performed using fibroblasts and endothelial, smooth muscle, and mast cells. All cell types expressed PGES and COX-2, resulting in basal levels of PGE(2) synthesis. In response to tumor necrosis factor (TNF-α), IL-1ß, and cocultured lymphocytes, however, mPGES-1 and COX-2 protein expression increased in fibroblasts and smooth muscle cells, accompanied by increased PGE(2), whereas mPGES-2 and cPGES were unaffected. In endothelial cells, TNF-α increased PGE(2) production only via COX-2 expression, whereas in mast cells the cytokines did not affect PGE(2) enzyme expression or PGE(2) production. Furthermore, PGE(2) production was diminished in gingival fibroblasts derived from mPGES-1 knockout mice, compared with wild-type fibroblasts. These results suggest that fibroblasts and smooth muscle cells are important sources of mPGES-1, which may contribute to increased PGE(2) production in the inflammatory condition periodontitis.