Ghazal Aarabi

Interaction between periodontal disease and atherosclerotic vascular disease – Fact or fiction?

C-reactive protein (CRP) level is associated with the 10-year risk of an atherosclerotic vascular disease (ASVD), suggesting presence of systemic inflammation probably long before ASVD is present. Where, however, does this systemic inflammation come from? One active area of research has been the study of dental infection and various forms of periodontal disease (PD), both of which are highly prevalent in populations at risk for ASVD. Recent data show that ASVD and PD interact with each other via systemic release of specific pro- and anti-inflammatory cytokines, small signal molecules and enzymes which modulate initiation and progression of the chronic inflammatory reaction involved in both diseases. In addition, periodontal pathogens were identified within atherosclerotic lesions and thrombi isolated from myocardial infarction patients. LDL cholesterol, a strong risk factor for ASVD, is also associated with PD; and statins, used to treat ASVD, are also active to prevent or reduce PD. Finally, there is growing evidence for common genetic susceptibility factors involved in both diseases. These findings support commonalities with respect to the pathogenic mechanisms involved in both inflammatory diseases. Conversely, a causative relationship cannot yet be concluded in the absence of data from large longitudinal cohort and randomized controlled intervention trials.

Genetic Susceptibility Contributing to Periodontal and Cardiovascular Disease

Periodontal disease (PD) and coronary artery disease (CAD) are common diseases characterized by an overaggressive inflammatory response to diverse stimuli. Whereas PD leads to destruction of the tooth-supporting structures, CAD is a chronic inflammatory condition ultimately causing myocardial infarction via narrowing and occluding of blood vessels. Classical twin studies led to the conclusion that both complex diseases have a similar degree of heritability and that a significant fraction of the genetic factors accounting for this heritability is shared. Recent genome-wide association and large-scale candidate gene studies highlight that variations in >50 genes are associated with premature CAD, while variations in only 4 genes showing nominally significant associations with aggressive periodontitis and/or chronic periodontitis have so far been identified. Remarkably, 3 of the PD loci (75%) show shared associations with CAD (ANRIL/CDKN2B-AS1, PLG, CAMTA1/VAMP3), suggesting involvement of common pathogenic mechanisms. In this critical review, we highlight recent progress in identifying genetic markers and variants associated with PD, present their overlap with CAD, and discuss functional aspects. In addition, we answer why a significant fraction of the heritability of PD is still missing, and we suggest approaches that may be taken to close the gap.

Masking Ability of Bi- and Tri- Laminate All-Ceramic Veneers on Tooth-Colored Ceramic Discs

STATEMENT A predictable esthetic outcome is imperative when placing ceramic veneers. Discolored teeth pose a major challenge as sufficient material thickness is required to achieve a good esthetic result. There is limited evidence in the literature that compares the masking ability of multi-laminate veneers. PURPOSE The aim of this in-vitro study was to compare the masking ability of bi-laminate (BL) and tri-laminate (TL) all-ceramic veneers cemented on tooth-colored ceramic discs. MATERIALS AND METHODS A total of 40 veneers (shade A1, 10-mm diameter, 0.8-mm thick) were manufactured-20 BL veneers (0.4-mm pressable ceramic coping veneered with 0.4-mm thick enamel layer) and 20 TL veneers (0.4-mm coping veneered with 0.2-mm thick opaque interlayer and 0.2-mm thick enamel layer). A bonding apparatus was utilized to adhesively cement all veneers on the ceramic discs (shade A1), simulating teeth of light and dark color. The resulting groups (N = 10 each) were the reference groups (shade A1 ceramic base) BL-1 and TL-1 veneers, and the test groups (shade A4 ceramic base) BL-4 and TL-4 veneers. The color of the cemented veneers was measured using a spectrophotometer. The data were converted to CIE L*a*b* coordinates, and ΔE* were calculated to allow for statistical analysis. RESULTS The color differences between the samples with the A1 and A4 ceramic bases were significantly lower when covered with TL veneers (mean ΔE*: 3.2 units) than with BL veneers (mean ΔE*: 4.0 units: p < 0.001), indicating a better masking ability of the TL veneers. CONCLUSION The 0.8-mm thick TL veneer was able to mask darker tooth-colored ceramic disc within clinically acceptable limits. CLINICAL SIGNIFICANCE Increased understanding of the masking ability of ceramics and of color science is necessary in these esthetically aware times. Providing tri-laminate veneers for darker colored teeth seems to result in more predictable esthetical results than when using bi-laminate veneers. Patients with discolored/darker teeth may benefit from a more predictable esthetic result when teeth restored with tri-laminate rather than bi-laminate veneers.

Chronic oral infection: An emerging risk factor of cerebral small vessel disease

Chronic oral infections (gingivitis/periodontitis) have been associated with age-related diseases such as diabetes, coronary heart disease, and acute ischemic stroke. In addition, imaging surrogates of cerebrovascular ischemia beyond acute ischemic stroke (i.e., silent strokes and brain white matter hyperintensities) may also be associated with chronic oral infections. The pathology underlying lacunar strokes and brain white matter hyperintensities (WMH) relates to small vessel disease in the brain. In this review, we highlight recent progress in exploring potential associations of oral infections with cerebral small vessel disease and its surrogates (silent strokes, white matter hyperintensities) and clinical sequelae (i.e., vascular dementia). Recent evidence suggests that periodontitis aggravates cerebral small vessel disease and increases lacunar stroke risk. Moreover, periodontitis interacts with Alzheimers disease to increase the severity of clinical dementia and to accelerate its manifestations. The results suggest that periodontitis may be an emerging risk factor of small vessel disease-associated cerebrovascular disorders and that the risk increase may be mediated by the systemic inflammation resulting from chronic oral infections. Large cohort studies employing state-of-the-art magnetic resonance techniques to identify specific cerebral pathologies as a function of time, oral health status, and systemic inflammation are needed to further substantiate the hypothesis.

Oral health and access to dental care – a comparison of elderly migrants and non-migrants in Germany

ABSTRACT Objectives: To compare oral health, access barriers to dental care, oral health behavior and oral hygiene behavior of elderly German residents with and without immigration background. Design: In this cross-sectional explorative study, a convenience sample (N = 112, age ≥ 60 years, 54% immigrants) was recruited in four dental practices in Hamburg, Germany. Oral health was assessed with Decayed/Missing/Filled Teeth (DMFT), Papillary Bleeding Index (PBI), and Approximal Plaque Index (API). Dental health was operationalized as number of decayed teeth, and poor oral hygiene based on a PBI ≥ 40%. Access barriers and oral health behavior were assessed with a standardized questionnaire. Results: While caries experience was similar in migrants and non-migrants (DMFT mean: 24.8 vs. 23.4, n.s.), significantly more teeth were decayed (5.3 vs. 2.1, p < 0.001), and API (55.3% vs. 33.0%, p = 0.002) and PBI (46.3% vs. 30.5%, p = 0.016) were significantly higher in migrants. After adjusting for age, sex, income, education, and number of teeth, migrants still had on average 3 decayed teeth more than non-migrants. However, impact of migration background on poor oral health changed from OR = 3.61 (p = 0.007) to OR = 1.05 (n.s.) after adjusting for confounders, mainly due to lower income in migrants. Fewer migrants had visited a dentist within the past 12 months, and migrants were less likely to have a regular dentist that they visit and more often indicated language or cost barriers than non-migrants. Conclusion: Elderly German migrants have higher treatment needs than non-migrants. Likely causes are poorer oral hygiene and lower utilization of dental care services. Specific prevention programs targeting migrants are warranted to improve oral health in this disadvantaged group.

Roles of Oral Infections in the Pathomechanism of Atherosclerosis

Oral infections occur frequently in humans and often lead to chronic inflammations affecting the teeth (i.e., caries), the gingival tissues surrounding the teeth (i.e., gingivitis and endodontic lesions), and the tooth-supporting structures (i.e., periodontitis). At least four basic pathogenic mechanisms have been proposed that involve oral inflammations in the pathogenesis of atherosclerosis: (1) low level bacteremia by which oral bacteria enter the blood stream and invade the arterial wall; (2) systemic inflammation induced by inflammatory mediators released from the sites of the oral inflammation into the blood stream; (3) autoimmunity to host proteins caused by the host immune response to specific components of oral pathogens; (4) pro-atherogenic effects resulting from specific bacterial toxins that are produced by oral pathogenic bacteria. In this narrative review, we summarize published experimental evidence related to these four mechanisms and discuss their impact on the pathogenesis of atherosclerosis.

Roles of the Chr.9p21.3 ANRIL locus in regulating inflammation and implications for anti-inflammatory drug target identification

Periodontitis (PD) is a common gingival infectious disease caused by an over-aggressive inflammatory reaction to dysbiosis of the oral microbiome. The disease induces a profound systemic inflammatory host response, that triggers endothelial dysfunction and pro-thrombosis and thus may aggravate atherosclerotic vascular disease and its clinical complications. Recently, a risk haplotype at the ANRIL/CDKN2B-AS1 locus on chromosome 9p21.3, that is not only associated with coronary artery disease / myocardial infarction (CAD/MI) but also with PD, could be identified by genome-wide association studies. The locus encodes ANRIL - a long non-coding RNA (lncRNA) which, like other lncRNAs, regulates genome methylation via interacting with specific DNA sequences and proteins, such as DNA methyltranferases and polycomb proteins, thereby affecting expression of multiple genes by cis and trans mechanisms. Here, we describe ANRIL regulated genes and metabolic pathways and discuss implications of the findings for target identification of drugs with potentially anti-inflammatory activity in general.

Potential Impact of Oral Inflammations on Cardiac Functions and Atrial Fibrillation

Inflammation may be a risk factor for atrial fibrillation (AF). Oral infections frequently lead to chronic inflammation, such as gingivitis, periodontitis, and endodontic lesions. In this narrative review, we consider five basic pathogenic mechanisms that involve oral infections and inflammations in the pathogenesis of AF: (1) low level bacteremia by which oral bacteria enter the blood stream at inflamed sites of the oral cavity and invade the heart; (2) Systemic inflammation induced by inflammatory mediators, which are released from the sites of oral inflammation into the blood stream, affecting cardiac remodeling; (3) autoimmunity against molecular structures expressed in the heart caused by the host immune response to specific components of oral pathogens; (4) potentially arrhythmic effects mediated by activation of the autonomous nervous system triggered by oral inflammations; and (5) arrhythmic effects resulting from specific bacterial toxins that are produced by oral pathogenic bacteria. A number of studies support the involvement of all five mechanisms, suggesting a potentially complex contribution of oral inflammations to the pathogenesis of AF.

Handling of Polyvinylsiloxane Versus Polyether for Implant Impressions

PURPOSE This study compared polyvinylsiloxane with polyether in handling dental impressions. MATERIALS AND METHODS Each participant (N = 39) made four impressions, each a combination of pickup and reseating techniques with polyether or polyvinylsiloxane, of one implant cast representing a specific clinical situation (tooth gaps, limited residual dentition, or edentulous jaw). Handling of impressions was subsequently rated by using a 12-item questionnaire with 100-mm visual analog scales. RESULTS While mean satisfaction scores were higher for polyvinylsiloxane than for polyether (69.5/63.0, P < .001), differences among subgroups were statistically significant only for pickup technique, limited residual dentition, and edentulous jaw. CONCLUSION Implant impressions made with polyvinylsiloxane using a pickup technique seem to be the best option for most clinical situations.