Oral infections and orofacial pain in Alzheimer's disease: a case-control study

Periodontal health status of people with dementia - A systematic review of case-control studies

Background

The number of older people increases globally, so is the risk of cognitive impairment. Periodontal diseases are common among older adults with significant tooth loss and periodontal problems. Thus, this review explored the periodontal disease conditions among individuals with and without dementia.

Methods

Available databases such as Medline/Pubmed, Web of Science, Scopus, Cochrane Library and Embase/OVID were used in the search. Case-control studies reporting on periodontal disease and dementia parameters were selected based on PICO (Population, Intervention, Comparison and Outcomes) framework. A Newcastle-Ottawa Scale (NOS) was used to assess the quality reporting of the studies and PRISMA guideline was used for screening.

Results

A total of ten studies were identified for analysis. Most studies reported higher plaque index score (PI), bleeding on probing (BoP), pocket depth (PD) and clinical attachment loss (CAL) among individuals diagnosed with dementia or Alzheimer's disease compared with clinically healthy controls or individual diagnosed without dementia. A higher prevalence of subjects with severe periodontal disease was also observed in individuals diagnosed with dementia/Alzheimer's disease. The quality of the studies was found to be moderate with lower comparability and ascertainment criteria scores.

Conclusion

This qualitative analysis has shown poor periodontal health and increased inflammatory mediators in case groups compared to the control groups. Thus, more quality studies and novel intervention are warranted to reduce the impact of periodontal health on dementia globally.

Factors Associated With Function-Focused Care Among Hospitalized Older Adults Living With Dementia

This article reports a study that was designed to describe the incidence of pain among older hospitalized patients with dementia and to evaluate the factors that influence pain among these individuals. It was hypothesized that function, behavioral and psychological symptoms of dementia, delirium, pain treatment, and patient exposure to care interventions would be associated with pain. Patients who performed more functional activities had less delirium. They also experienced higher quality-of-care interactions and were less likely to have pain. The findings from this study support the relationship between function, delirium, and quality-of-care interactions and pain. It suggests that it may be useful to encourage patients with dementia to engage in functional and physical activity to prevent or manage pain. This study serves as a reminder to avoid neutral or negative care interactions among patients with dementia as a strategy to mediate delirium and pain.

Confounding in observational studies evaluating the association between Alzheimer's disease and periodontal disease: A systematic review

Background

Studies investigating the association between periodontitis and Alzheimer's disease (AD) suggested indirect (periodontitis would increase the circulation of inflammation-inducible molecules) and direct (periodontopathogens might colonize brains affected by Alzheimer's disease) pathways. While there seems to be a positive relationship between periodontitis and AD, concerns have been raised about the role of confounding.

Aim

To systematically review the literature to assess confounding and their level of heterogeneity in the association between periodontitis and AD. Also, to examine data reporting and interpretation regarding confounding bias.

Methods

This review followed the PRISMA guidelines and was registered within PROSPERO. Electronic searches were performed in seven main databases and three others to capture the "grey literature". The PECO strategy was used to identify observational studies (cross-sectional, case-control, or cohort studies) assessing the association between periodontal disease and AD without restricting publication language and year. Critical appraisal was performed according to the Joanna Briggs Institute guidelines. Confounders were evaluated following a two-step approach.

Results

A total of 3255 studies were found, of which 18 (13 case-control, four cross-sectional, and one cohort) met the eligibility criteria. Participants with AD were 1399 (mean age 64 ± 9 to 84.8 ± 5.6 years), whereas those without AD were 1730 (mean age 62.6 ± 7.1 to 81.4 ± 4.6). Female patients composed most of the sample for both groups. The confounding variables "age" and "sex" were present in all studies. Four studies used the 2017 AAP/EFP periodontal classification. Most studies had a low risk of bias. Fifty percent of the articles did not consider confounding; variation in the adjustment approaches was observed. Additionally, 62% of the studies did not mention bias, and 40% did not discuss any limitations about confounders.

Conclusions

Given the study's limitations, caution must be taken to properly interpret the association between periodontitis and AD.Registration: CRD42022293884.

Is Periodontitis Associated with Age-Related Cognitive Impairment? The Systematic Review, Confounders Assessment and Meta-Analysis of Clinical Studies

It has been suggested that molecular pathological mechanisms responsible for periodontitis can be linked with biochemical alterations in neurodegenerative disorders. Hypothetically, chronic systemic inflammation as a response to periodontitis plays a role in the etiology of cognitive impairment. This study aimed to determine whether periodontitis (PDS) is a risk factor for age-related cognitive impairment (ACI) based on evidence of clinical studies. A comprehensive, structured systematic review of existing data adhering to the Preferred Reporting Items for Systematic Review and Meta Analyses (PRISMA) guidelines was carried out. Five electronic databases, PubMed, Embase, Scopus, Web of Science, and Cochrane, were searched for key terms published in peer-reviewed journals until January 2021. The Newcastle-Ottawa scale was used to assess the quality of studies and risk of bias. The primary and residual confounders were explored and evaluated. A meta-analysis synthesizing quantitative data was carried out using a random-effects model. Seventeen clinical studies were identified, including 14 cohort, one cross-sectional, and two case-control studies. Study samples ranged from 85 to 262,349 subjects, with follow-up between 2 and 32 years, and age above 45 years, except for two studies. The findings of studies suggesting the PDS-ACI relationship revealed substantial differences in design and methods. A noticeable variation related to the treatment of confounders was observed. Quality assessment unveiled a moderate quality of evidence and risk of bias. The subgroups meta-analysis and pooled sensitivity analysis of results from seven eligible studies demonstrated overall that the presence of PDS is associated with an increased risk of incidence of cognitive impairment (OR = 1.36, 95% CI 1.03-1.79), particularly dementia (OR = 1.39, 95% CI 1.02-1.88) and Alzheimer's disease (OR = 1.03 95% CI 0.98-1.07)). However, a considerable heterogeneity of synthesized data (I2 = 96%) and potential publication bias might affect obtained results. While there is a moderate statistical association between periodontitis and dementia, as well as Alzheimer's disease, the risk of bias in the evidence prevents conclusions being drawn about the role of periodontitis as a risk factor for age-related cognitive impairment.

Understanding Pain and Agitation Through System Analysis Algorithms in People With Dementia. A Novel Explorative Approach by the DIGI.PAIN Study

Background

Many people with dementia (PwD) live and die with undiagnosed and untreated pain and are no longer able to report their suffering. Several pain assessment tools have been developed, tested, and implemented in clinical practice, but nursing home patients are reported to be still in pain. Clinicians and research groups worldwide are seeking novel approaches to encode the prediction, prevalence, and associations to pain in PwD.

Participants

The data in this analysis are acquired from the COSMOS study, a cluster-randomized controlled trial (2014 to 2015), aimed to improve the quality of life in nursing home patients (N = 723) through the implementation of a multicomponent intervention. We utilize baseline data of PwD (N = 219) with complete datasets of pain and agitation.

Method

Systems analysis explores the relationship between pain and agitation using the Mobilization-Observation-Behavior-Intensity-Dementia (MOBID-2) Pain Scale, Cohen-Mansfield Agitation Inventory (CMAI), and Neuropsychiatric Inventory-Nursing Home version (NPI-NH). For each patient, the individualized continuous time trajectory, and rates of change of pain and agitation are estimated. We determine the relationship between these rates by analyzing them across the entire group.

Results

We found that the new analysis method can generate individualized estimations for pain and agitation evolution for PwD, as well as their relationship. For 189 of 219 PwD, results show that whenever pain increases or decreases, agitation does too, with the same rate. The method also identifies PwD for whom pain or agitation remains constant while the other varies over time, and patients for whom agitation and pain do not change together. The algorithm is scalable to other variables and compatible with wearable devices and digital sensors.

Conclusion

We presented a new approach to clinical data analysis using systems concepts and algorithms. We found that it is possible to quantify and visualize relationships between variables with a precision only dependent on the precision of measurements. This method should be further validated, but incipient results show great potential, especially for wearable-generated continuous data.

Dementia and the Risk of Periodontitis: A Population-Based Cohort Study

Dementia and Alzheimer's disease (AD) are proposed to be comorbid with periodontitis (PD). It is unclear whether PD is associated with dementia and AD independent of confounding factors. We aimed at identifying the relationship between the longitudinal risk of developing PD in a cohort of patients with dementia and AD who did not show any signs of PD at baseline. In this retrospective cohort study, 8,640 patients with dementia without prior PD were recruited, and 8,640 individuals without dementia history were selected as propensity score-matched controls. A Cox proportional hazard model was developed to estimate the risk of developing PD over 10 y. Cumulative probability was derived to assess the time-dependent effect of dementia on PD. Of the 8,640 patients, a sensitivity test was conducted on 606 patients with AD-associated dementia and 606 non-AD propensity score-matched controls to identify the impact of AD-associated dementia on the risk for PD. Subgroup analyses on age stratification were included. Overall 2,670 patients with dementia developed PD. The relative risk of PD in these patients was significantly higher than in the nondementia group (1.825, 95% CI = 1.715 to 1.942). Cox proportional hazard models showed that patients with dementia were more likely to have PD than individuals without dementia (adjusted hazard ratio = 1.915, 95% CI = 1.766 to 2.077, P < 0.0001, log-rank test P < 0.0001). The risk of PD in patients with dementia was age dependent (P values for all ages <0.0001); younger patients with dementia were more likely to develop PD. The findings persisted for patients with AD: the relative risk (1.531, 95% CI = 1.209 to 1.939) and adjusted hazard ratio (1.667, 95% CI = 1.244 to 2.232; log-rank test P = 0.0004) of PD in patients with AD were significantly higher than the non-AD cohort. Our findings demonstrated that dementia and AD were associated with a higher risk of PD dependent of age and independent of systemic confounding factors.

Brain-derived neurotrophic factor in Alzheimer's disease and its pharmaceutical potential

Synaptic abnormalities are a cardinal feature of Alzheimer's disease (AD) that are known to arise as the disease progresses. A growing body of evidence suggests that pathological alterations to neuronal circuits and synapses may provide a mechanistic link between amyloid β (Aβ) and tau pathology and thus may serve as an obligatory relay of the cognitive impairment in AD. Brain-derived neurotrophic factors (BDNFs) play an important role in maintaining synaptic plasticity in learning and memory. Considering AD as a synaptic disorder, BDNF has attracted increasing attention as a potential diagnostic biomarker and a therapeutical molecule for AD. Although depletion of BDNF has been linked with Aβ accumulation, tau phosphorylation, neuroinflammation and neuronal apoptosis, the exact mechanisms underlying the effect of impaired BDNF signaling on AD are still unknown. Here, we present an overview of how BDNF genomic structure is connected to factors that regulate BDNF signaling. We then discuss the role of BDNF in AD and the potential of BDNF-targeting therapeutics for AD.

Evidence and Therapeutic Perspectives in the Relationship between the Oral Microbiome and Alzheimer's Disease: A Systematic Review

This review aims to clarify the nature of the link between Alzheimer’s disease and the oral microbiome on an epidemiological and pathophysiological level, as well as to highlight new therapeutic perspectives that contribute to the management of this disease. We performed a systematic review, following the Preferred Reporting Items for Systematic Reviews checklist, from January 2000 to July 2021. The terms “plaque,” “saliva,” and “mouth” were associated with the search term “oral diseases” and used in combination with the Boolean operator “AND”/“OR”. We included experimental or clinical studies and excluded conferences, abstracts, reviews, and editorials. A total of 27 articles were selected. Evidence for the impact of the oral microbiome on the pathophysiological and immunoinflammatory mechanisms of Alzheimer’s disease is accumulating. The impact of the oral microbiome on the development of AD opens the door to complementary therapies such as phototherapy and/or the use of prebiotic compounds and probiotic strains for global or targeted modulation of the oral microbiome in order to have a favourable influence on the evolution of this pathology in the future.

Pathophysiological association between periodontal disease and Alzheimer's disease: Importance of periodontal health in the elderly

BACKGROUND

As the global aging population is rapidly advancing, recognizing the full potential of periodontal disease (PD) in the onset or progression of Alzheimer's disease (AD) is important for reducing geriatric morbidity. This review explores the possible role of PD in the pathogenesis of AD, as the pathological mechanisms underlying AD are the most well-studied among all types of dementia. The investigation was conducted using the electronic academic databases PubMed and ScienceDirect, employing a combination of keywords "periodontal disease," "periodontitis," "Alzheimer's disease," "dementia," and "Porphyromonas gingivalis." After applying the selection and eligibility criteria and removing overlaps, from an initial search finding of 5933 studies, 11 were finally included for qualitative analysis.

HIGHLIGHT

The inflammatory reaction induced by oral pathogenic bacteria related to PD, through complex pathways, may exacerbate inflammation in the central nervous system, thereby contributing to the progression of AD.

CONCLUSION

Maintenance of adequate oral hygiene in patients diagnosed with AD is significant because they suffer from a gradual loss of manual dexterity as the disease advances. Additionally, the evidence presents the potential of systemic inflammation from PD-induced pathogenic bacteria, illustrating the grave cyclical progression of AD.

The Association of Periodontitis and Alzheimer's Disease: How to Hit Two Birds with One Stone

Alzheimer's disease (AD) is the leading cause of cognitive impairment in the elderly. Recent evidence suggests that preventive interventional trials could significantly reduce the risk for development of dementia. Periodontitis is the most common dental disease characterized by chronic inflammation and loss of alveolar bone and perialveolar attachment of teeth. Growing number of studies propose a potential link between periodontitis and neurodegeneration. In the first part of the paper, we overview case-control studies analyzing the prevalence of periodontitis among AD patients and healthy controls. Second, we survey observational libraries and cross-sectional studies investigating the risk of cognitive decline in patients with periodontitis. Next, we describe the current view on the mechanism of periodontitis linked neural damage, highlighting bacterial invasion of neural tissue from dental plaques, and periodontitis induced systemic inflammation resulting in a neuroinflammatory process. Later, we summarize reports connecting the four most common periodontal pathogens to AD pathology. Finally, we provide a practical guide for further prevalence and interventional studies on the management of cognitively high-risk patients with and without periodontitis. In this section, we highlight strategies for risk control, patient information, dental evaluation, reporting protocol and dental procedures in the clinical management of patients with a risk for periodontitis and with diagnosed periodontitis. In conclusion, our review summarizes the current view on the association between AD and periodontitis and provides a research and intervention strategy for harmonized interventional trials and for further case-control or cross-sectional studies.

Analysis the Link between Periodontal Diseases and Alzheimer's Disease: A Systematic Review

The hypothesis of an infectious connection from the oro-pharyngeal sphere to the brain underlines the interest in analyzing the link between periodontal disease and Alzheimer’s disease. The aim of this systematic review was to examine the link between Alzheimer’s disease and periodontal disease in patients aged 65 and over. Databases (PubMed (MEDLINE), the Cochrane Library, and Embase) were analyzed for relevant references up to 21 June 2021. The authors independently selected the studies and extracted the data. The quality of included studies was checked using the National Institutes of Health’s quality assessment tools. Five studies were included. The selected studies described in their results an increase in F. nucleatum in Alzheimer’s disease patients (adjusted p = 0.02), and its incidence was linked to C. rectus and P. gingivalis (adjusted HR = 1.22 (1.04–1.43), p = 0.012) as well as A. naeslundii (crude HR = 2.0 (1.1–3.8)). The presence of periodontitis at baseline was associated with a six-fold increase in the rate of cognitive decline over a 6-month follow-up period (ADAS-Cog mean change = 2.9 ± 6.6). The current review suggests an association between periodontal disease and Alzheimer’s disease. The treatment of periodontal disease could be a way to explore Alzheimer’s disease prevention.

Instruments for pain assessment in patients with advanced dementia: A systematic review of the evidence for Latin America

OBJECTIVE

Pain treatment is an essential component of care for elderly patients with advanced dementia. The objective of this study was to identify and analyze the different scales used for pain assessment in elderly persons diagnosed with dementia, in the literature available at the Latin American level.

METHOD

A systematic review was performed on the existing scales for pain assessment in elderly people diagnosed with Alzheimer's disease, vascular dementia, and dementia with Lewy bodies.

RESULTS

226 articles were retrieved from the PUBMED, BIREME, and Scielo databases, of which a total of 10 articles entered the systematic review. The instruments identified in these publications were PAINAD, Abbey, McGill, and PACSLAC, while the Colored Pain Scale, Faces Pain Scale, and VAS scales were used as the silver standard. In Spanish, the Abbey scale, and in Portuguese, the PACSLAC scale showed the best reliability and validity coefficients.

SIGNIFICANCE OF RESULTS

It is concluded that there are only two appropriate scales for the assessment of pain in people with dementia in the region of interest of this study. It is recommended to generate more evidence for a more accurate assessment of pain in people with dementia.

Influence of cognitive impairment and dementia on oral health and the utilization of dental services : Findings of the Oral Health, Bite force and Dementia Study (OrBiD)

BACKGROUND

The aim of this study was to show the influence of cognitive impairment and dementia on oral health and on the utilization of dental services.

METHODS

A cross-sectional analyzation of data of the OrBiD (Oral Health, Bite Force and Dementia) pilot study was conducted. 137 subjects were stratified into five dementia groups on the basis of the Mini Mental State Examination (MMSE) (1-no dementia (MMSE 28-30), 2-mild cognitive impairment (MMSE 25-27), 3-mild dementia (MMSE 18-24), 4-moderate dementia (MMSE 10-17), and 5-severe dementia (MMSE < 10)). Information on the utilization of dental services and oral health parameters (DMFT index, degree of restoration, Periodontal Screening Index, Bleeding on Probing, Oral Hygiene Index, Denture Hygiene Index) were collected.

RESULTS

An increase in dementia resulted in significant reduction in utilization. Moreover, with increasing cognitive impairment/dementia there was a significant difference in the number of teeth that were decayed, but not in the number of filled or missing teeth or the DMF/T index itself. With increasing dementia, the degree of restoration decreased and oral/denture hygiene deteriorated significantly. Nevertheless, periodontal therapy was required for all subjects independent of their degree of dementia while bleeding on probing was increasing with increasing dementia.

CONCLUSIONS

An influence of cognitive impairment and dementia on oral health and on the utilization of dental services was shown. However, no conclusions about the influence of the utilization behavior of people with dementia on oral health parameters can be drawn. Further longitudinal studies are needed. Trial registration ClinicalTrials.gov NCT03775772. Registered 14th December 2018, https://clinicaltrials.gov/ct2/show/NCT03775772 .

The Effect of Periodontitis on Dementia and Cognitive Impairment: A Meta-Analysis

The association between periodontal disease and dementia/cognitive impairment continues to receive increasing attention. However, whether periodontal disease is a risk factor for dementia/cognitive impairment is still uncertain. This meta-analysis was conducted to comprehensively analyze the effect of periodontitis on dementia and cognitive impairment, and to assess the periodontal status of dementia patients at the same time. A literature search was undertaken on 19 October 2020 using PubMed, Web of Science, and Embase with different search terms. Two evaluators screened studies according to inclusion and exclusion criteria, and a third evaluator was involved if there were disagreements; this process was the same as that used for data extraction. Included studies were assessed with the Newcastle-Ottawa Scale (NOS), and results were analyzed using software Review Manager 5.2. Twenty observational studies were included. In the comparison between periodontitis and cognitive impairment, the odds ratio (OR) was 1.77 (95% confidence interval (CI), 1.31–2.38), which indicated that there was a strong relationship between periodontitis and cognitive impairment. There was no statistical significance in the effect of periodontitis on dementia (OR = 1.59; 95%CI, 0.92–2.76). The subgroup analysis revealed that moderate or severe periodontitis was significantly associated with dementia (OR = 2.13; 95%CI, 1.25–3.64). The mean difference (MD) of the community periodontal index (CPI) and clinical attachment level (CAL) was 0.25 (95%CI, 0.09–0.40) and 1.22 (95%CI, 0.61–1.83), respectively. In this meta-analysis, there was an association between periodontitis and cognitive impairment, and moderate or severe periodontitis was a risk factor for dementia. Additionally, the deterioration of periodontal status was observed among dementia patients.

Influence of periodontal disease on risk of dementia: a systematic literature review and a meta-analysis

Periodontal disease (PD) is common and increases cardiovascular diseases. However, it is unclear whether PD is associated with increased risk of dementia. We carried out a systematic review and meta-analysis to investigate the influence of PD on dementia. We projected the number of dementia cases to be saved by reducing PD prevalence in the world. We searched cohort and case-control studies reporting the association of PD with all dementia (or any specific type of dementia) through PubMed, MEDLINE, PsycINFO, SocINDEX, CINHAL, and CNKI until 7th November 2018. Five cohorts and seven case-control studies were identified for review. We pooled eligible data to calculate relative risk (RR) of dementia in relation to PD and computed the number of dementia cases saved through reducing PD prevalence. Of 12 studies, six were undertaken in Asia, four in Europe and two in America. Eleven studies showed a positive association between PD and the risk of dementia, of which 10 were significant, and one reported a non-significant inverse association. Overall their quality was good. Pooled RR of dementia in relation to PD from all high quality studies was 1.38 (95%CI 1.01-1.90); in the five cohorts was 1.18 (1.06-1.31) and in the two case-control studies 2.25 (1.48-3.42). A 50% reduction in the current prevalence of 20% of PD in the population could save 850,000 (630,000-1,420,000) patients with dementia in the world. PD could increase the risk of incident dementia. Preventing and treating PD could contribute to controlling the global epidemic of dementia.

The Orofacial Pain Clinic Questionnaire (EDOF-HC) in the evaluation and diagnosis of orofacial pain

ABSTRACT Background: Diagnostic tools are necessary for the anamnesis and examination of orofacial pain, in order to fulfill diagnostic criteria and to screen potential causes of pain. Objective: To evaluate the Orofacial Pain Clinic Questionnaire (EDOF-HC) in the assessment and diagnosis of orofacial pain. Methods: Overall, 142 patients were evaluated and classified according to the criteria of the International Headache Society and International Association for the Study of Pain. All of them were evaluated with the EDOF-HC questionnaire, which consists of the orofacial and medical history, as well as the orofacial examination. Data were statistically analyzed with chi-square test and Bonferroni correction, one-way ANOVA with Tukey post hoc test, the two-step cluster and decision tree methods. Results: There were diferences in pain descriptors, pain in maximum mouth opening, number of trigger points, and history of previous surgery between the groups, which were classified into trigeminal neuralgia, burning mouth syndrome, temporomandibular disorders and trigeminal posttraumatic neuropathic pain with classification analysis. Conclusions: The EDOF-HC is a clinical supportive tool for the assessment of orofacial pain. The instrument may be used to support data collection from anamnesis and examination of patients according to the diagnostic criteria of most common orofacial conditions. It is also useful in the investigation of local and systemic abnormalities and contributes for the diagnosis of conditions that depend on exclusion criteria.

Prevalence and associations of orofacial pain and oral health factors in nursing home residents with and without dementia

OBJECTIVES

determine and compare the prevalence of orofacial pain in older nursing home residents with and without dementia and explore the association between orofacial pain and health factors.

METHODS

cross-sectional study conducted in four UK nursing homes. We used the Orofacial-Pain Scale for Non-Verbal Individuals (OPS-NVI) to identify orofacial pain in residents with dementia. Residents who were able to communicate self-reported orofacial pain. A brief oral examination was conducted. Information on demographics, Clinical Dementia Rating, Charlson Comorbidity Index, Cohen Mansfield Agitation Inventory, Barthel Index, 5-level Euroqol 5 Dimension, Oral Health Impact Profile 14, Mini Nutritional Assessment Short Form and medication was collected. Chi-squared tests, independent sample t-tests and Mann-Whitney U-tests were used to compare outcomes between groups. Multivariable logistic regression was used to evaluate predictors of orofacial pain.

RESULTS

orofacial pain, assessed with the OPS-NVI, was present in 48.8% (95% confidence interval [C.I.] 36.1-50.7) of residents with dementia. Self-reported orofacial pain was present in 37.8% (95% C.I. 20.4-53.7) of residents with dementia and in 14.8% (95% C.I. 0.5-30.4) residents without dementia. Orofacial pain was significantly more prevalent in residents with dementia than those without (OPS-NVI; P = 0.002, self-report; P = 0.04). Having a soft diet, xerostomia, being dentate, and poor oral hygiene in dentate residents were significant predictors of orofacial pain in residents with dementia.

CONCLUSION

orofacial pain was more prevalent in residents with dementia. Oral health care should be part of routine care for residents, especially for those with dementia, to improve oral health and decrease the risk of developing orofacial pain.

The Role of Periodontitis and Periodontal Bacteria in the Onset and Progression of Alzheimer's Disease: A Systematic Review

The evidence of a connection between the peripheral inflammatory processes and neurodegenerative diseases of the central nervous system is becoming more apparent. This review of the related literature highlights the most recent clinical, epidemiological, and in vitro studies trying to investigate possible connections between periodontal bacteria and the onset and progression of Alzheimer’s disease. This review was conducted by searching databases such as PubMed and Scopus using keywords or combinations such as Alzheimer’s Disease AND periodontal or dementia AND periodontitis OR periodontal. After eliminating overlaps and screening the articles not related to these issues, we identified 1088 records and proceeded to the selection of articles for an evaluation of the associative assumptions. The hypothesis suggested by the authors and confirmed by the literature is that the bacterial load and the inflammatory process linked to periodontal disease can intensify inflammation at the level of the central nervous system, favoring the occurrence of the disease. The analysis of the literature highlights how periodontal disease can directly contribute to the peripheral inflammatory environment by the introduction of periodontal or indirect pathogenic bacteria and proinflammatory cytokines locally produced at the periodontal level following bacterial colonization of periodontal defects.

Oral microbiota and Alzheimer's disease: Do all roads lead to Rome?

Alzheimer's disease (AD) is a progressive neurodegenerative pathology affecting milions of people worldwide associated with deposition of senile plaques. While the genetic and environmental risk factors associated with the onset and consolidation of late onset AD are heterogeneous and sporadic, growing evidence also suggests a potential link between some infectious diseases caused by oral microbiota and AD. Oral microbiota dysbiosis is purported to contribute either directly to amyloid protein production, or indirectly to neuroinflammation, occurring as a consequence of bacterial invasion. Over the last decade, the development of Human Oral Microbiome database (HOMD) has deepened our understanding of oral microbes and their different roles during the human lifetime. Oral pathogens mostly cause caries, periodontal disease, and edentulism in aged population, and, in particular, alterations of the oral microbiota causing chronic periodontal disease have been associated with the risk of AD. Here we describe how different alterations of the oral microbiota may be linked to AD, highlighting the importance of a good oral hygiene for the prevention of oral microbiota dysbiosis.

Oral Health Status and Need for Oral Care in an Aging Population: A Systematic Review

Background. The world population is aging. This phenomenon is accompanied by an increase in the number of elderly with dementia, whose oral hygiene care is a challenge. Objective. This paper presents a literature review of oral health status and the need for oral care in people with dementia, as compared to people without dementia and also of the relationship between periodontal disease and cognitive impairment. Methods. A systematic review was conducted in PubMed, CINAHL, and the Cochrane Library. Fifty-six articles met the inclusion criteria and were consequently included for quality assessment and data extraction. Results. No significant differences were found between both groups with regard to the number of present teeth, DMFT Index, edentulousness/use of denture, and orofacial pain. Coronal/root caries and retained roots were more common in people with dementia than in those without dementia. Most of the participants with dementia presented gingival bleeding or inflammation and they suffered from the periodontal disease more than people without dementia. Conclusions. Poor oral health is a common condition among the elderly with dementia. The education process of caregivers might improve the oral health status of people with dementia. Finally, periodontal disease might contribute to the onset or progression of dementia.

Association between periodontitis and risk of Alzheimer's disease, mild cognitive impairment and subjective cognitive decline: A case-control study

AIMS

To test the hypothesis that periodontal disease contributes to increased risk of mild cognitive impairment (MCI), subjective cognitive decline (SCD) and Alzheimer's disease (AD).

MATERIALS AND METHODS

This case-control study was conducted over a 3-year period in the municipality of Huddinge, Sweden. In total, 154 cases were consecutively enrolled from the Karolinska Memory Clinic at the Karolinska University Hospital and allotted to three diagnostic groups: AD, MCI and SCD, collectively referred to as "cases." Seventy-six cognitively healthy age- and gender-matched controls were randomly sampled through the Swedish population register. All cases and controls underwent clinical and radiographic oral examinations. Statistical analysis was based on logistic regression models adjusted for potential confounders.

RESULTS

Poor oral health and marginal alveolar bone loss were more prevalent among cases than among controls. The cases group was associated with generalized marginal alveolar bone loss (odds ratio [OR] = 5.81; 95% confidence interval [CI] = 1.14-29.68), increased number of deep periodontal pockets (OR = 8.43; CI 4.00-17.76) and dental caries (OR = 3.36; CI 1.20-9.43).

CONCLUSION

The results suggest that marginal periodontitis is associated with early cognitive impairment and AD. However, the study design does not preclude noncausal explanations.

The Possible Causal Link of Periodontitis to Neuropsychiatric Disorders: More Than Psychosocial Mechanisms

Increasing evidence implies a possible causal link between periodontitis and neuropsychiatric disorders, such as Alzheimer’s disease (AD) and major depression (MD). A possible mechanism underlying such a link can be explained by neuroinflammation induced by chronic systemic inflammation. This review article focuses on an overview of the biological and epidemiological evidence for a feasible causal link of periodontitis to neuropsychiatric disorders, including AD, MD, Parkinson’s disease, and schizophrenia, as well as the neurological event, ischemic stroke. If there is such a link, a broad spectrum of neuropsychiatric disorders associated with neuroinflammation could be preventable and modifiable by simple daily dealings for oral hygiene. However, the notion that periodontitis is a risk factor for neuropsychiatric disorders remains to be effectively substantiated.

The Association between Tooth Loss and Alzheimer's Disease: a Systematic Review with Meta-Analysis of Case Control Studies

Alzheimer's disease is classified as a neurodegenerative condition, a heterogeneous group of illnesses characterized by the slow and progressive loss of one or more functions of the nervous system. Its incidence tends to increase gradually from 65 years of age, up to a prevalence of 4% at age 75. The loss of dental elements is more prevalent in this population and might negatively affect the masticatory capacity, quality of life, and pathogenesis of Alzheimer's disease. This study investigated problems related to oral health and the loss of dental elements in elderly patients suffering from Alzheimer's and considered whether local inflammatory processes could affect the etiopathogenesis of Alzheimer's disease. The purpose of this systematic review is to identify a link between the causes leading to tooth loss and the onset/progression of Alzheimer's disease. We also studied whether there is a higher incidence of tooth loss (primary outcome) and edentulism (secondary outcome) among Alzheimer's patients. We searched records in electronic databases such as PubMed, EBSCO, and Web of Science using the following keywords: Alzheimer's Disease AND periodontal, Alzheimer's Disease AND periodontitis, dementia AND (periodontitis OR periodontal) "Alzheimer's Disease" AND "tooth" OR "dental loss," "dementia" AND "edentulous," "Alzheimer's Disease" AND "edentulous," "dementia" AND "tooth" OR "dental loss." The records were screened, and after applying the eligibility and inclusion criteria, nine articles were left, six of which were analyzed for the primary outcome (loss of dental elements) and six for the secondary outcome (tooth loss). Results from this meta-analysis revealed that Alzheimer's disease patients have an increased risk of dental loss (hazard ratio (HR) 1.52, 95% confidence interval (CI) 1.00-2.30, p = 0.05) and edentulous condition (HR 2.26, 95% CI 1.70-3.01, p < 0.001). A quantitative analysis of the included studies indicated that patients suffering from Alzheimer's disease are characterized by a greater number of lost dental elements and general edentulism compared to the control groups.

Orofacial pain and its potential oral causes in older people with mild cognitive impairment or dementia

Background

The number of people with dementia and natural dentition is growing. As dementia progresses, the degree of self‐care decreases and the risk of oral health problems and orofacial pain increases.

Objectives

To examine and compare the presence of orofacial pain and its potential causes in older people with Mild Cognitive Impairment (MCI) or dementia.

Methods

In this cross‐sectional observational study, the presence of orofacial pain and its potential causes was studied in 348 participants with MCI or dementia with all levels of cognitive impairment in two outpatient memory clinics and ten nursing homes.

Results

Orofacial pain was reported by 25.7% of the 179 participants who were considered to present a reliable pain self‐report (Mini‐Mental State Examination score ≥14 points), while it could not be determined in people with more severe cognitive impairment. The oral health examination of the 348 participants indicated that potential painful conditions, such as coronal caries, root caries, tooth root remnants or ulcers were present in 50.3%. There was a significant correlation between the level of cognitive impairment and the number of teeth, r = 0.185, P = 0.003, teeth with coronal caries, r = −0.238, P < 0.001, and the number of tooth root remnants, r = −0.229, P = 0.004, after adjusting for age.

Conclusions

This study indicated that orofacial pain and its potential causes were frequently present in participants with MCI or dementia. Therefore, a regular oral examination by (oral) healthcare providers in people with MCI or dementia remains imperative, even if no pain is reported.

The Potential of LPS-Binding Protein to Reverse Amyloid Formation in Plasma Fibrin of Individuals With Alzheimer-Type Dementia

Many studies indicate that there is a (mainly dormant) microbial component in the progressive development of Alzheimer-type dementias (ADs); and that in the case of Gram-negative organisms, a chief culprit might be the shedding of the highly inflammagenic lipopolysaccharide (LPS) from their cell walls. We have recently shown that a highly sensitive assay for the presence of free LPS [added to platelet poor plasma (PPP)] lies in its ability (in healthy individuals) to induce blood to clot into an amyloid form. This may be observed in a SEM or in a confocal microscope when suitable amyloid stains (such as thioflavin T) are added. This process could be inhibited by human lipopolysaccharide-binding protein (LBP). In the current paper, we show using scanning electron microscopy and confocal microscopy with amyloid markers, that PPP taken from individuals with AD exhibits considerable amyloid structure when clotting is initiated with thrombin but without added LPS. Furthermore, we could show that this amyloid structure may be reversed by the addition of very small amounts of LBP. This provides further evidence for a role of microbes and their inflammagenic cell wall products and that these products may be involved in pathological clotting in individuals with AD.

Oral health and orofacial pain in people with dementia admitted to acute hospital wards: observational cohort study

Background

Orofacial pain in people with dementia is difficult to detect, and often under-treated. Our aim was to investigate the prevalence of orofacial pain in people with dementia in acute hospitals in the UK. Secondary aims were to examine oral health status and explore associations between orofacial pain and oral health factors.

Methods

This cross-sectional observational study was carried out in two UK hospitals. Using the Orofacial Pain Scale in Non-Verbal Individuals (OPS-NVI) to identify orofacial pain, 101 participants with dementia, admitted to acute medical wards, were observed for at least 3 min during rest and chewing. Verbal participants were then asked about presence of orofacial pain, using self-report pain scales. Finally, a brief oral assessment was performed.

Results

Orofacial pain, assessed with the OPS-NVI, was present in 11.9% (95% C.I. 5.9, 18.8) of participants at rest and 21.9% (95% C.I. 14.6, 31.3) whilst chewing. Participants who were no longer able to self-report pain were significantly more likely to experience orofacial pain. Oral health in both dentate and edentate participants was poor. Brush frequency, indication of chewing quality, consistency of the food, presence of extra-oral abnormalities, person who performed mouth care, and oral hygiene in dentate participants were significant predictors for the presence of orofacial pain.

Conclusion

Improving oral care in acute hospital patients with dementia, particularly those who cannot self-report pain, may significantly reduce pain and suffering in this population.

Electronic supplementary material

The online version of this article (10.1186/s12877-018-0810-7) contains supplementary material, which is available to authorized users.

Periodontal disease severity in subjects with dementia: A systematic review and meta-analysis

BACKGROUND AND OBJECTIVE

Despite clinical trials and reviews attempt to assess a possible relationship between dementia and periodontal disease, no meta-analysis has been performed and this issue remains undetermined. The aim of this study is to conduct a systematic review and meta-analysis to assess severity of periodontitis in subjects with dementia.

METHODS

The search was conducted in Pubmed, Embase/MEDLINE. Two independent reviewers extracted data and assessed the risk bias (Newcastle-Ottawa scale). Meta-analyses were performed using the means of probing depth (PD) and clinical attachment loss (CAL) in patients with or without dementia. The mean difference were analyzed (P ≤ 0.05).

RESULTS

Fourteen studies were included in the systematic review. In the qualitative analysis, most studies reported higher prevalence of periodontal disease in dementia patients. The studies had low risk of bias and two meta-analyses were performed for each parameter, including or not a cross-sectional study. The meta-analyses including the cross-sectional study demonstrated significant association between dementia and periodontal disease (mean difference: PD = 1.41; CAL = 1.40, P < 0.05), however, it wasn't confirmed when the cross-sectional study was removed (1.25 mm, P < 0.22) and CAL (1.20 mm, P < 0.22).

CONCLUSION

Although the qualitative analysis have suggested worse periodontal conditions in dementia patients, due to different study types and the high heterogeneity among them, the meta-analysis does not support the association between dementia and severity of periodontal disease.

Oral hygiene and oral health in older people with dementia: a comprehensive review with focus on oral soft tissues

BACKGROUND

The number of older people with dementia and a natural dentition is growing. Recently, a systematic review concerning the oral health of older people with dementia with the focus on diseases of oral hard tissues was published.

OBJECTIVE

To provide a comprehensive literature overview following a systematic approach of the level of oral hygiene and oral health status in older people with dementia with focus on oral soft tissues.

METHODS

A literature search was conducted in the databases PubMed, CINAHL, and the Cochrane Library. The following search terms were used: dementia and oral health or stomatognathic disease. A critical appraisal of the included studies was performed with the Newcastle-Ottawa scale (NOS) and Delphi list.

RESULTS

The searches yielded 549 unique articles, of which 36 were included for critical appraisal and data extraction. The included studies suggest that older people with dementia had high scores for gingival bleeding, periodontitis, plaque, and assistance for oral care. In addition, candidiasis, stomatitis, and reduced salivary flow were frequently present in older people with dementia.

CONCLUSIONS

The studies included in the current systematic review suggest that older people with dementia have high levels of plaque and many oral health problems related to oral soft tissues, such as gingival bleeding, periodontal pockets, stomatitis, mucosal lesions, and reduced salivary flow.

SCIENTIFIC RATIONALE FOR STUDY

With the aging of the population, a higher prevalence of dementia and an increase in oral health problems can be expected. It is of interest to have an overview of the prevalence of oral problems in people with dementia.

PRINCIPAL FINDINGS

Older people with dementia have multiple oral health problems related to oral soft tissues, such as gingival bleeding, periodontal pockets, mucosal lesions, and reduced salivary flow.

PRACTICAL IMPLICATIONS

The oral health and hygiene of older people with dementia is not sufficient and could be improved with oral care education of formal and informal caregivers and regular professional dental care to people with dementia.

Oral Infections and Cytokine Levels in Patients with Alzheimer's Disease and Mild Cognitive Impairment Compared with Controls

BACKGROUND

Oral infections are prevalent in the adult population. Their impact includes the implication as a risk factor for Alzheimer's disease (AD), altering its progression. One of the potential mechanisms involves immune mediators such as circulating cytokines.

OBJECTIVE

The goal of the present study was to investigate the prevalence of oral infections and blood levels of IL-1β, TNF-α, and IL-6 in patients with AD, mild cognitive impairment (MCI), and controls.

METHODS

Sixty-five elderly were evaluated (25 AD, 19 MCI, and 21 controls) by the following methods: Mini Mental State Exam, Questionnaire of Functional Activities, periodontal and oral evaluation, and blood concentrations of IL-1β, TNF-α and IL-6.

RESULTS

Patients with AD had high serum IL-6 levels (p = 0.029), and patients with periodontitis had high serum TNF-α levels (p = 0.005). There was an association between IL-6 and TNF-α in patients with AD/MCI and periodontitis (p = 0.023).

CONCLUSION

The increased levels of TNF-α and IL-6 in this study suggests their implication in the overlapping mechanisms between oral infections and AD. Longitudinal studies are necessary for further investigation.

Oral infections, comorbidities and sensory evidences in elderly: Cross-sectional study

BACKGROUND

Oral infections affect the general health and overlap with chronic diseases due to infectious-immune mechanisms. On the other side, sensory abnormalities may be symptoms of this association.

OBJECTIVE

To evaluate the prevalence of oral infections, comorbidities, health parameters and sensory abnormalities in elderly patients.

METHODS

Thirty (30) elderly with mean age 70.4 yo, distributed according to ages were evaluated with a protocol that included demographics, comorbidities, medications, laboratory tests, blood pressure, heart rate, mini-mental state examination, clinical oral evaluation and systematized sensory testing (gustative, olfactory, thermal, mechanical and pain thresholds). Data were tabled and statistically analyzed.

RESULTS

Twenty-three (76.6%) subjects had chronic diseases that increased according to the age. Seventeen (56.7%) elderly were having medication. Mean probing pocket depth was 1.90mm±0.39mm, mean clinical attachment level was 0.76mm±0.54mm and mean gingival bleeding index was 29.10%±29.05%. All periodontal indexes increased with age (p <0.05) and were associated with comorbidities and use of medication. Patients with chronic diseases had more numbness and pricking sensations (p=0.031; p=0.000). Main sensory findings were: abnormal gustative and vibratory thresholds, which were associated with hematological parameters (blood count, cholesterol levels and glycaemia). Periodontal parameters were associated with facial cold threshold (p=0.000).

CONCLUSION

This study showed an association between systemic diseases, periodontal indexes and sensory thresholds. Sensory findings were associated with blood parameters and are potential tools for periodical health evaluation. Inflammatory or neural mechanisms need further investigation.

Association between periodontal disease and dementia: A literature review

INTRODUCTION

Periodontal disease and dementia are very prevalent, especially in elderly populations. Multiple studies have shown a link between these diseases; however, the conditions are highly heterogeneous and so is the diagnostic methodology, which may hinder interpretation and comparison of the results. The aim of this article is to provide a critical review of the literature linking these 2 processes.

DEVELOPMENT

We retrieved 22 studies, most of which were retrospective, and analysed various methodological variables including study population, diagnosis of periodontitis, definition of dementia, adjusted variables, and results. The different aetiopathogenic mechanisms that may affect the progression and interaction of these 2 conditions were also analysed.

CONCLUSIONS

Although available evidence indicates a positive association between periodontitis and dementia, both the strength of that association and the presence of a causal relationship have yet to be determined.

Viscoelastic and ultrastructural characteristics of whole blood and plasma in Alzheimer-type dementia, and the possible role of bacterial lipopolysaccharides (LPS)

Alzheimer-type dementia (AD) is a neurodegenerative disorder and the most common form of dementia. Patients typically present with neuro- and systemic inflammation and iron dysregulation, associated with oxidative damage that reflects in hypercoagulability. Hypercoagulability is closely associated with increased fibrin(ogen) and in AD patients fibrin(ogen) has been implicated in the development of neuroinflammation and memory deficits. There is still no clear reason precisely why (a) this hypercoagulable state, (b) iron dysregulation and (c) increased fibrin(ogen) could together lead to the loss of neuronal structure and cognitive function. Here we suggest an alternative hypothesis based on previous ultrastructural evidence of the presence of a (dormant) blood microbiome in AD. Furthermore, we argue that bacterial cell wall components, such as the endotoxin lipopolysaccharide (LPS) of Gram-negative strains, might be the cause of the continuing and low-grade inflammation, characteristic of AD. Here, we follow an integrated approach, by studying the viscoelastic and ultrastructural properties of AD plasma and whole blood by using scanning electron microscopy, Thromboelastography (TEG^®) and the Global Thrombosis Test (GTT^®). Ultrastructural analysis confirmed the presence and close proximity of microbes to erythrocytes. TEG^® analysis showed a hypercoagulable state in AD. TEG^® results where LPS was added to naive blood showed the same trends as were found with the AD patients, while the GTT^® results (where only platelet activity is measured), were not affected by the added LPS, suggesting that LPS does not directly impact platelet function. Our findings reinforce the importance of further investigating the role of LPS in AD.

Oral health and orofacial pain in older people with dementia: a systematic review with focus on dental hard tissues

Objective

The aim of this review was to provide a systematic overview including a quality assessment of studies about oral health and orofacial pain in older people with dementia, compared to older people without dementia.

Methods

A systematic literature search was performed in PubMed, CINAHL, and the Cochrane Library. The following search terms were used: dementia and oral health or stomatognathic disease. The quality assessment of the included articles was performed using the Newcastle-Ottawa Scale (NOS).

Results

The search yielded 527 articles, of which 37 were included for the quality assessment and quantitative overview. The median NOS score of the included studies was 5, and the mean was 4.9 (SD 2.2). The heterogeneity between the studies was considered too large to perform a meta-analysis. An equivalent prevalence of orofacial pain, number of teeth present, decayed missing filled teeth index, edentulousness percentage, and denture use was found for both groups. However, the presence of caries and retained roots was higher in older people with dementia than in those without.

Conclusions

Older people with dementia have worse oral health, with more retained roots and coronal and root caries, when compared to older people without dementia. Little research focused on orofacial pain in older people with dementia.

Clinical relevance

The current state of oral health in older people with dementia could be improved with oral care education of caretakers and regular professional dental care.

Can oral infection be a risk factor for Alzheimer's disease?

Alzheimer's disease (AD) is a scourge of longevity that will drain enormous resources from public health budgets in the future. Currently, there is no diagnostic biomarker and/or treatment for this most common form of dementia in humans. AD can be of early familial-onset or sporadic with a late-onset. Apart from the two main hallmarks, amyloid-beta and neurofibrillary tangles, inflammation is a characteristic feature of AD neuropathology. Inflammation may be caused by a local central nervous system insult and/or by peripheral infections. Numerous microorganisms are suspected in AD brains ranging from bacteria (mainly oral and non-oral Treponema species), viruses (herpes simplex type I), and yeasts (Candida species). A causal relationship between periodontal pathogens and non-oral Treponema species of bacteria has been proposed via the amyloid-beta and inflammatory links. Periodontitis constitutes a peripheral oral infection that can provide the brain with intact bacteria and virulence factors and inflammatory mediators due to daily, transient bacteremias. If and when genetic risk factors meet environmental risk factors in the brain, disease is expressed, in which neurocognition may be impacted, leading to the development of dementia. To achieve the goal of finding a diagnostic biomarker and possible prophylactic treatment for AD, there is an initial need to solve the etiological puzzle contributing to its pathogenesis. This review therefore addresses oral infection as the plausible etiology of late-onset AD (LOAD).

Evaluation of patients with Alzheimer's disease before and after dental treatment

Oral infections may play a role in Alzheimer's disease (AD). Objective To describe the orofacial pain, dental characteristics and associated factors in patients with Alzheimer's Disease that underwent dental treatment. Method 29 patients with mild AD diagnosed by a neurologist were included. They fulfilled the Mini Mental State Exam and Pfeffer's questionnaire. A dentist performed a complete evaluation: clinical questionnaire; research diagnostic criteria for temporomandibular disorders; McGill pain questionnaire; oral health impact profile; decayed, missing and filled teeth index; and complete periodontal investigation. The protocol was applied before and after the dental treatment. Periodontal treatments (scaling), extractions and topic nystatin were the most frequent. Results There was a reduction in pain frequency (p=0.014), mandibular functional limitations (p=0.011) and periodontal indexes (p<0.05), and an improvement in quality of life (p=0.009) and functional impairment due to cognitive compromise (p<0.001) after the dental treatment. Orofacial complaints and intensity of pain also diminished. Conclusion The dental treatment contributed to reduce co-morbidities associated with AD and should be routinely included in the assessment of these patients.