What has ageing to do with periodontal health and disease?

Advances in the Study of the Pathology and Treatment of Alzheimer's Disease and Its Association with Periodontitis

Alzheimer's disease (AD) has become one of the leading causes of health problems in the elderly, and studying its causes and treatments remains a serious challenge for researchers worldwide. The two main pathological features of Alzheimer's disease are the extracellular deposition of β-amyloid (Aβ) to form senile plaques and the intracellular aggregation of hyperphosphorylated Tau protein to form neurofibrillary tangles (NFTs). Researchers have proposed several hypotheses to elucidate the pathogenesis of AD, but due to the complexity of the pathophysiologic factors involved in the development of AD, no effective drugs have been found to stop the progression of the disease. Currently, the mainstay drugs used to treat AD can only alleviate the patient's symptoms and do not have a therapeutic effect. As researchers explore interactions among diseases, much evidence suggests that there is a close link between periodontitis and AD, and that periodontal pathogenic bacteria can exacerbate Aβ deposition and Tau protein hyperphosphorylation through neuroinflammatory mechanisms, thereby advancing the pathogenesis of AD. This article reviews recent advances in the pathogenesis of AD, available therapeutic agents, the relevance of periodontitis to AD, and mechanisms of action.

Investigation on the association between serum lipid levels and periodontitis: a bidirectional Mendelian randomization analysis

OBJECTIVE

Several research has considered the potential correlation between periodontitis and serum lipids. However, serum lipid profiles correlation with periodontitis remains largely unknown. The investigation objective was to examine periodontitis correlation with serum lipid levels using a bidirectional Mendelian randomization (MR) analysis.

METHODS

The study employed a bidirectional MR analysis with two samples, utilizing a freely accessible genome-wide association study (GWAS). Furthermore, the primary analysis employed the inverse variance weighted (IVW) method. To determine whether the lipid profiles were associated with periodontitis, a variety of sensitivity analyses (including MR-Egger regression, MR-PRESSO, and weighted median), as well as multivariable MR, were employed.

RESULTS

MR analysis performed by IVW did not reveal any relationship between periodontitis and low-density lipoprotein (LDL), high-density lipoprotein (HDL), triglycerides (TG), or total cholesterol (TC). It was also found that LDL, HDL, TG, and TC were not associated to periodontitis. Furthermore, the MR estimations exhibited consistency with other MR sensitivity and multivariate MR (MVMR) analyses. These results show that the correlation between serum lipid levels and periodontitis could not be established.

CONCLUSION

The finding indicates a negligible link between periodontitis and serum lipid levels were identified, despite previous observational studies reporting a link between periodontitis and serum lipid levels.

Physical activity as a proxy to ameliorate inflammation in patients with type 2 diabetes and periodontal disease at high cardiovascular risk

While the beneficial impact of physical activity has been ascertained in a variety of pathological scenarios, including diabetes and low-grade systemic inflammation, its potential remains still putative for periodontal health. Periodontal disease has been associated with inflammatory systemic alterations, which share a common denominator with type 2 diabetes mellitus and cardiovascular disease. Physical exercise, along with nutritional counseling, is a cornerstone in the treatment and prevention of type 2 diabetes, also able to reduce the prevalence of periodontal disease and cardiovascular risk. In addition, considering the higher incidence of periodontitis in patients with type 2 diabetes compared to healthy controls, the fascinating research question would be whether physical activity could relieve the inflammatory pressure exerted by the combination of these two diseases. This multi-disciplinary viewpoint discusses available literature in order to argument the hypothesis of a "three-way relationship" linking diabetes, periodontitis, and physical activity.

Inhibitory Effect of Asplenium incisum on Bacterial Growth, Inflammation, and Osteoclastogenesis

Background and Objectives:Asplenium incisum, a natural plant, is known to possess numerous pharmacological and biochemical properties. However, the inhibitory effect of A. incisum against Porphyromonas gingivalis and other factors related to periodontal disease have not yet been demonstrated. This study aimed to investigate the potential of A. incisum extract as a phytotherapeutic candidate for improving periodontal diseases by assessing its antibacterial, anti-inflammatory, and anti-osteoclastogenic activities. Materials and Methods: The inhibition of proliferation of P. gingivalis by A. incisum and the sustainability of its antibacterial activity were evaluated in this study. The production of inflammatory cytokines (tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6)) and nitric oxide (NO) from lipopolysaccharide-stimulated RAW 264.7 cells was assessed using an enzyme-linked immunosorbent assay. To identify the anti-osteoclastogenic activity, tartrate-resistant acid phosphatase (TRAP) staining and TRAP activity analyses were performed on bone marrow macrophages. Results: The proliferation of P. gingivalis was significantly inhibited by A. incisum (p < 0.001), and the antibacterial activity was sustained for up to 3 days. A. incisum showed anti-inflammatory activities by significantly decreasing the release of TNF-α, IL-6 (p < 0.05), and NO (p < 0.01). In addition, A. incisum significantly suppressed TRAP-positive cells and TRAP activity (at 30 μg/mL, p < 0.01) without causing any cytotoxicity (p > 0.05). Conclusions:A. incisum showed antibacterial, anti-inflammatory, and anti-osteoclastogenic activities, suggesting it has strong therapeutic potential against periodontal diseases.

The Effect of Gaseous Ozone Therapy in Conjunction with Periodontal Treatment on Glycated Hemoglobin Level in Subjects with Type 2 Diabetes Mellitus: An Unmasked Randomized Controlled Trial

BACKGROUND

It is established that inflammation is involved in the pathogenesis of Type 2 Diabetes Mellitus (T2DM) by promoting insulin resistance and impaired beta cell function in the pancreas. Among the hypothesized independent risk factors implicated in the pathogenetic basis of disease, periodontal infection has been proposed to promote an amplification of the magnitude of the advanced glycation end product (AGE)-mediated upregulation of cytokine synthesis and secretion. These findings suggest an interrelationship between periodontal disease and type 2 diabetes, describing poor metabolic control in subjects with periodontitis as compared to nondiabetic subjects and more severe periodontitis in subjects with T2DM as compared to a healthy population, with a significant positive correlation between periodontal inflammatory parameters and glycated hemoglobin level. Results from clinical trials show that periodontal treatment is able to improve glycemic control in subjects with diabetes. Many therapeutic strategies have been developed to improve periodontal conditions in conjunction with conventional treatment, among which ozone (O₃) is of specific concern. The principal aim of this trial was to compare the clinical effectiveness of an intensive periodontal intervention consisting of conventional periodontal treatment in conjunction with ozone gas therapy in reducing glycated hemoglobin level in type 2 diabetic patients and standard periodontal treatment.

METHODS

This study was a 12-month unmasked randomized trial and included 100 patients aged 40-74 years older, with type 2 diabetes mellitus diagnosed. All the patients received conventional periodontal treatment, or periodontal treatment in conjunction with ozone gas therapy in a randomly assigned order (1:1). The primary outcome was a clinical measure of glycated hemoglobin level at 3, 6, 9 and 12 months from randomization. Secondary outcomes were changes in periodontal inflammatory parameters.

RESULTS

At 12 months, the periodontal treatment in conjunction with ozone gas therapy did not show significant differences than standard therapy in decreasing glycated hemoglobin (HbA1C) level and the lack of significant differences in balance is evident.

CONCLUSIONS

Although the change was not significant, periodontal treatment in conjunction with the gaseous ozone therapy tended to reduce the levels of glycated hemoglobin. The study shows a benefit with ozone therapy as compared to traditional periodontal treatment.

The effect of periodontal treatment on hemoglobin a1c levels of diabetic patients: a systematic review and meta-analysis. PLoS One. 2014;9:e108412. [PMID: 25255331 PMCID: PMC4177914 DOI: 10.1371/journal.pone.0108412]

Background

There is growing evidence that periodontal treatment may affect glycemic control in diabetic patients. And several systematic reviews have been conducted to assess the effect of periodontal treatment on diabetes outcomes. Researches of this aspect are widely concerned, and several new controlled trials have been published. The aim of this study was to update the account for recent findings.

Methods

A literature search (until the end of January 2014) was carried out using various databases with language restriction to English. A randomized controlled trial (RCT) was selected if it investigated periodontal therapy for diabetic subjects compared with a control group received no periodontal treatment for at least 3 months of the follow-up period. The primary outcome was hemoglobin A1c (HbA1c), and secondary outcomes were periodontal parameters included probing pocket depth (PPD) and clinical attachment level (CAL).

Results

Ten trials of 1135 patients were included in the analysis. After the follow-up of 3 months, treatment substantially lowered HbA1c compared with no treatment after periodontal therapy (–0.36%, 95%CI, −0.52% to −0.19%, P<0.0001). Clinically substantial and statistically significant reduction of PPD and CAL were found between subjects with and without treatment after periodontal therapy (PPD −0.42 mm, 95%CI: −0.60 to −0.23, P<0.00001; CAL −0.34 mm, 95%CI: −0.52 to −0.16, P = 0.0002). And there is no significant change of the level of HbA1c at the 6-month comparing with no treatment (–0.30%, 95%CI, −0.69% to 0.09%, P = 0.13).

Conclusions

Periodontal treatment leads to the modest reduction in HbA1c along with the improvement of periodontal status in diabetic patients for 3 months, and this result is consistent with previous systematic reviews. And the effect of periodontal treatment on HbA1c cannot be observed at 6-month after treatment.

Diagnosis and anti-infective therapy of periodontitis

Periodontal diseases (gingivitis and periodontitis) are chronic bacterial infections with a remarkably high prevalence and morbidity. Periodontitis, in contrast to gingivitis, is not reversible, is associated with certain bacterial species and affects all of the soft tissue and bone that support teeth. Among the periodontal pathogens, species, such as Aggregatibacter (Actinobacillus) actinomycetemcomitans, Porphyromonas gingivalis, Prevotella intermedia, Tannerella forsythensis, and several forms of uncultivable spirochetes play the major role in the pathogenesis. In severe chronic, recurrent and especially aggressive forms of periodontitis, diagnosis of the species involved and, whenever possible, an optimized evidence-based antimicrobial treatment is indicated. In order to monitor alarming bacterial changes in the periodontal pocket, several techniques, namely microscopy, culture, immunoassays, enzyme tests and DNA-based techniques, have been established and the methods are described in the first part of this review. In the second part, the selection and use of locally delivered (topical) and systemic antibiotics used adjunctively in periodontal therapy are discussed.

A phage display selected 7-mer peptide inhibitor of the Tannerella forsythia metalloprotease-like enzyme Karilysin can be truncated to Ser-Trp-Phe-Pro

Tannerella forsythia is a gram-negative bacteria, which is strongly associated with the development of periodontal disease. Karilysin is a newly identified metalloprotease-like enzyme, that is secreted from T. forsythia. Karilysin modulates the host immune response and is therefore considered a likely drug target. In this study peptides were selected towards the catalytic domain from Karilysin (Kly18) by phage display. The peptides were linear with low micromolar binding affinities. The two best binders (peptide14 and peptide15), shared the consensus sequence XWFPXXXGGG. A peptide15 fusion with Maltose Binding protein (MBP) was produced with peptide15 fused to the N-terminus of MBP. The peptide15-MBP was expressed in E. coli and the purified fusion-protein was used to verify Kly18 specific binding. Chemically synthesised peptide15 (SWFPLRSGGG) could inhibit the enzymatic activity of both Kly18 and intact Karilysin (Kly48). Furthermore, peptide15 could slow down the autoprocessing of intact Kly48 to Kly18. The WFP motif was important for inhibition and a truncation study further demonstrated that the N-terminal serine was also essential for Kly18 inhibition. The SWFP peptide had a Ki value in the low micromolar range, which was similar to the intact peptide15. In conclusion SWFP is the first reported inhibitor of Karilysin and can be used as a valuable tool in structure-function studies of Karilysin.

The structure of the catalytic domain of Tannerella forsythia karilysin reveals it is a bacterial xenologue of animal matrix metalloproteinases

Metallopeptidases (MPs) are among virulence factors secreted by pathogenic bacteria at the site of infection. One such pathogen is Tannerella forsythia, a member of the microbial consortium that causes peridontitis, arguably the most prevalent infective chronic inflammatory disease known to mankind. The only reported MP secreted by T. forsythia is karilysin, a 52 kDa multidomain protein comprising a central 18 kDa catalytic domain (CD), termed Kly18, flanked by domains unrelated to any known protein. We analysed the 3D structure of Kly18 in the absence and presence of Mg(2+) or Ca(2+) , which are required for function and stability, and found that it evidences most of the structural features characteristic of the CDs of mammalian matrix metalloproteinases (MMPs). Unexpectedly, a peptide was bound to the active-site cleft of Kly18 mimicking a left-behind cleavage product, which revealed that the specificity pocket accommodates bulky hydrophobic side-chains of substrates as in mammalian MMPs. In addition, Kly18 displayed a unique Mg(2+) or Ca(2+) binding site and two flexible segments that could play a role in substrate binding. Phylogenetic and sequence similarity studies revealed that Kly18 is evolutionarily much closer to winged-insect and mammalian MMPs than to potential bacterial counterparts found by genomic sequencing projects. Therefore, we conclude that this first structurally characterized non-mammalian MMP is a xenologue co-opted through horizontal gene transfer during the intimate coexistence between T. forsythia and humans or other animals, in a very rare case of gene shuffling from eukaryotes to prokaryotes. Subsequently, this protein would have evolved in a bacterial environment to give rise to full-length karilysin that is furnished with unique flanking domains that do not conform to the general multidomain architecture of animal MMPs.

Effect of periodontal treatment on glycemic control of diabetic patients: a systematic review and meta-analysis

OBJECTIVE

There is growing evidence that periodontitis may affect general health. This study was assigned to explore the robustness of observations that periodontal therapy leads to the improvement of glycemic control in diabetic patients.

RESEARCH DESIGN AND METHODS

A literature search (until March 2009) was carried out using two databases (MEDLINE and the Cochrane Library) with language restriction to English. Selection of publications was based on 1) original investigations, 2) controlled periodontal intervention studies where the diabetic control group received no periodontal treatment, and 3) study duration of > or =3 months.

RESULTS

Screening of the initial 639 identified studies and reference checking resulted in five suitable articles. A total of 371 patients were included in this analysis with periodontitis as predictor and the actual absolute change in A1C (DeltaA1C) as the outcome. The duration of follow-up was 3-9 months. All studies described a research population of type 2 diabetic patients in whom glycemic control improved after periodontal therapy compared with the control group (range DeltaA1C: Delta-1.17 up to Delta-0.05%). The studies in a meta-analysis demonstrated a weighted mean difference of DeltaA1C before and after therapy of -0.40% (95% CI -0.77 to -0.04%, P = 0.03) favoring periodontal intervention in type 2 diabetic patients. Nevertheless, this improvement in %A1C must be interpreted with care due to limited robustness as evidenced by heterogeneity among studies (59.5%, P = 0.04).

CONCLUSIONS

The present meta-analysis suggests that periodontal treatment leads to an improvement of glycemic control in type 2 diabetic patients for at least 3 months.

Effect of Age on Gingival Crevicular Fluid Concentrations of MIF and PGE 2

We used an experimental gingivitis study design to compare crevicular fluid concentrations of Migration Inhibitory Factor (MIF) and Prostaglandin E2 (PGE2) in younger (18 to 30 yrs) and older (46 to 77 yrs) healthy adults. PGE2 increased after 1 wk in younger participants, whereas it decreased in older individuals after 1 wk of plaque accumulation. A significant interaction between age and time was observed for PGE2 (p = 0.04). High concentrations of MIF were identified in both age groups at baseline. MIF increased in the younger participants, whereas in the older individuals a decrease over time was observed. MIF concentration was positively correlated with plaque index and gingival index in the older age group. Total counts of bacteria, Parvimonas micra and Prevotella intermedia, were significantly correlated with MIF concentration in older participants. In conclusion, MIF and PGE2 production in response to bacterial accumulation seems to be modified by age.

TMJ osteoarthritis/osteoarthrosis and immune system factors in a Japanese sample

OBJECTIVE

To determine whether there is an association between temporomandibular joint (TMJ) osteoarthritis/osteoarthrosis (OA) and immune system factors in a Japanese sample.

MATERIALS AND METHODS

The records of 41 subjects (7 men, aged 22.0 +/- 3.8 years; 34 women, aged 24.8 +/- 6.3 years) and 41 pair-matched controls (7 men, aged 22.1 +/- 2.3 years; 34 women, aged 24.8 +/- 6.4 years) based on age and gender were reviewed. Information on medical history included local or systemic diseases, details on medication type and use, and the presence of allergies and asthma. Dental history questions referred to details regarding past oral injuries. The validity of the hypothesis, defining allergies and asthma as risk factors in OA, was tested by using a logistic regression analysis.

RESULTS

The incidence of allergy was significantly higher in the TMJ OA (P = .008), with a mean odds ratio of 4.125 and a 95% confidence interval of 1.446-11.769.

CONCLUSION

These results suggest that allergy may be a risk factor in association with TMJ OA in this Japanese sample.

Neighbourhood deprivation and dental service use: a cross-sectional analysis of older people in England

BACKGROUND

Appropriate dental care is an important part of maintaining good oral health. We examined the relationship between socioeconomic status, neighbourhood deprivation levels and older people's dental service use.

METHODS

We used logistic regression analysis to assess the relationship between self-reported dental service use and neighbourhood deprivation, adjusting for individual socioeconomic and health factors, in individuals aged 65+ in the 2005 Health Survey for England (n = 4240).

RESULTS

Among dentulous respondents, 69.9% reported attending for regular check-ups, 6.2% occasional check-ups, 18.4% only saw a dentist when in trouble and 5.6% never went to a dentist. In our adjusted model age, sex, region, education level, occupational social class, self-reported health and smoking status, but not degree of urbanization, were associated with use of dental services. Following adjustment for these other factors those living in the most deprived 20% of neighbourhoods, compared with those in the least deprived, had a relative risk ratio of 2.25 (95% confidence interval 1.59-3.17) of using dental services only when symptomatic, rather than going for regular or occasional check-ups. When alternative outcomes of reporting having recently seen a doctor or been a hospital inpatient were assessed these deprivation-related patterns in service use were not evident.

CONCLUSION

Levels of neighbourhood deprivation are associated with the use of dental services by older people. Action is needed to ensure older people in deprived communities access appropriate and comprehensive dental services.

The oral cavity of elderly patients in diabetes

Diabetes mellitus is a common and growing global health problem leading to several complications. Among these periodontal diseases are considered as the sixth complication of diabetes mellitus. This article reviews the relationship between diabetes and oral health, particularly focusing on periodontal diseases, dental caries and xerostomia. There is a bidirectional interrelationship between diabetes and periodontal diseases. Periodontitis is more prevalent and severe in patients with diabetes than in normal population. Therapy of periodontal infection contributes to a positive glycaemic control management and enables reduction of the burden of complications of diabetes mellitus. Diabetics have an increased predisposition to the manifestation of oral diseases like candidiasis which is associated with poor glycaemic control and therapeutic dentures. This predisposition also contributes to xerostomia, which may be due to increased glucose levels in oral fluids or immune dysregulation.

Is there a relation between local bone quality as assessed on panoramic radiographs and alveolar bone level?

The aim was to explore the relation between radiographic bone quality on panoramic radiographs and relative alveolar bone level. Digital panoramic radiographs of 94 female patients were analysed (mean age, 44.5; range, 35-74). Radiographic density of the alveolar bone in the premolar region was determined using Agfa Musica software. Alveolar bone level and bone quality index (BQI) were also assessed. Relationships between bone density and BQI on one hand and the relative loss of alveolar bone level on the other were assessed. Mandibular bone density and loss of alveolar bone level were weakly but significantly negatively correlated for the lower premolar area (r = -.27). The BQI did not show a statistically significant relation to alveolar bone level. Radiographic mandibular bone density on panoramic radiographs shows a weak but significant relation to alveolar bone level, with more periodontal breakdown for less dense alveolar bone.