Relationship between periodontal disease and osteoporosis

Association between dietary patterns and periodontal disease: The OsteoPerio cohort study

AIM

To examine the association of dietary patterns with periodontal disease (PD) and its progression over 5 years.

MATERIALS AND METHODS

Analyses involved 1197 post-menopausal women from the OsteoPerio cohort. Dietary patterns assessed include Healthy Eating Index-2015 (HEI), Alternative HEI (AHEI), Dietary Approaches to Stop Hypertension (DASH) and alternate Mediterranean Diet (aMed) at baseline (the average of two food frequency questionnaires administered between 1993 and 2001). At baseline and the 5-year follow-up, periodontal assessments evaluated alveolar crestal height (ACH), probing pocket depth (PPD), clinical attachment loss (CAL), percentage of gingival sites bleeding on probing (%BOP) and missing teeth due to PD. Linear and logistic regression were used to examine the associations.

RESULTS

Cross-sectionally, HEI and aMed were associated with smaller CAL and %BOP; along with DASH, they were associated with a decreased odds of teeth missing due to PD. AHEI and aMed were associated with a decreased odds of severe PD. Prospectively, AHEI was associated with greater ACH progression. This association was attenuated to the null after loss of ACH was imputed for teeth lost due to PD over follow-up, or after excluding participants with diabetes, osteoporosis, hypertension or heart disease at baseline.

CONCLUSIONS

Better adherence to healthy dietary patterns was associated with better PD measures cross-sectionally but greater progression of ACH over 5 years. The latter might be explained by incident tooth loss due to PD and pre-existing comorbidities.

Geriatric Phenotypes and Their Impact on Oral Health

Older adults have multiple morbidities that can impact oral, systemic, and psychological health. Although each disorder requires consideration from the provider before treatment, by assessing the common phenotypic presentations of older adults, we can better understand, select, and coordinate treatment modifications that would need to be considered and implemented for dental care.

Geriatric Phenotypes and Their Impact on Oral Health

Older adults have multiple morbidities that can impact oral, systemic, and psychological health. Although each disorder requires consideration from the provider before treatment, by assessing the common phenotypic presentations of older adults, we can better understand, select, and coordinate treatment modifications that would need to be considered and implemented for dental care.

The relationship between hormone replacement therapy and periodontal disease in postmenopausal women: a cross-sectional study the Korea National Health and Nutrition Examination Survey from 2007 to 2012

Background

The purpose of this study was to investigate the relationship between hormone replacement therapy (HRT) and periodontal disease in postmenopausal women using data from the 4th and 5th Korea National Health and Nutrition Examination Survey (KNHANES).

Methods

The study included data from 5,482 postmenopausal women aged 45–74 years in the 2007–2012 KNHANES. The use of female HRT for at least one month was reclassified as HRT+/HRT-. The Community Periodontal Index of Treatment Needs (CPITN) was used to assess periodontal status. Propensity score matching (PSM) was used to control selection bias, and factors affecting education, family income, and age of menopause were used as covariates in PSM. A chi-square test was used to confirm the bivariate relationship between the variables. Binary logistic regression analysis was used to adjust for confounders (age, education, family income, body mass index, age of menopause, alcohol, smoking, dental clinic visits in the past one year, use of oral care products and frequency of tooth brushing per day).

Results

After adjusting for all covariates, HRT was associated with periodontal disease (OR: 0.79; 95% CI: 0.66–0.94). In particular, the relationship between HRT and periodontal disease was more evident in those with menopause under 45 years of age disease (OR: 0.55; 95% CI: 0.35–0.87).

Conclusions

The results of this study supported that it is important that hormone therapy be actively considered in the policy towards postmenopausal women. Especially, health programs such as hormone replacement therapy, non-smoking, and use of oral care products are needed for women who undergo premature menopause.

Orthogonal test design for optimization of the extraction of essential oil from Asarum heterotropoides var. Mandshuricum and evaluation of its antibacterial activity against periodontal pathogens

The optimum extraction conditions of essential oil from Asarum heterotropoides var. Mandshuricum applied by an orthogonal L₉(3³) test were a water-to-raw material ratio of 17, a particle size of D ₉₅ ≤ 3.8 mm and an extraction time of 2 h. In ingredient analysis, gas chromatography/mass spectrometry analysis identified the main components of essential oil as methyl eugenol (45.95%), safrole (17.48%) and 3,5-dimethoxytoluene (10.30%) orderly. In vitro, the minimum inhibitory concentration and minimum bactericidal concentration of essential oil were 0.01 and 0.02% against F. nucleatum, 0.04 and 0.08% against P. intermedia, and 0.005 and 0.005% against P. gingivalis. In vivo, administration of essential oil significantly suppressed alveolar bone resorption induced by F. nucleatum, with bone levels remaining comparable to non-infected mice. These results of antibacterial activity of essential oil in vitro and in vivo show the inhibition of periodontal pathogens and therapy of alveolar bone resorption in mice, suggesting that its essential oil could be a potential natural therapeutic agent for treatment of periodontitis in human beings.

Plants and Their Bioactive Constituents in Mesenchymal Stem Cell-Based Periodontal Regeneration: A Novel Prospective

Periodontitis is a common chronic inflammatory disease, which causes the destruction of both the soft and mineralized tissues. However, current treatments such as bone graft materials, barrier membranes, and protein products all have difficulties in regenerating the complete periodontal tissue structure. Stem cell-based tissue engineering has now emerged as one of the most effective treatments for the patients suffering from periodontal diseases. Plants not only can be substrates for life processes, but also contain hormones or functional molecules. Numbers of preclinical studies have revealed that products from plant can be successfully applied in modulating proliferation and differentiation of human mesenchymal stem cells. Plant-derived substances can induce stem cells osteogenic differentiation, and they also possess angiogenic potency. Furthermore, in the field of tissue engineering, plant-derived compounds or plant extracts can be incorporated with biomaterials or utilized as biomaterials for cell transplantation. So it is speculated that botanical products may become a new perspective in stem cell-based periodontal regeneration. However, the lack of achieving predict clinical efficacy and quality control has been the major impediment to its extensive application. This review gives an overview of the prospect of applying different plant-derived substances in various human mesenchymal stem cells-based periodontal regeneration.

Regulation of bone remodeling by vitamin K2

All living tissues require essential nutrients such as amino acids, fatty acids, carbohydrates, minerals, vitamins, and water. The skeleton requires nutrients for development, maintaining bone mass and density. If the skeletal nutritional requirements are not met, the consequences can be quite severe. In recent years, there has been growing interest in promotion of bone health and inhibition of vascular calcification by vitamin K2. This vitamin regulates bone remodeling, an important process necessary to maintain adult bone. Bone remodeling involves removal of old or damaged bone by osteoclasts and its replacement by new bone formed by osteoblasts. The remodeling process is tightly regulated, when the balance between bone resorption and bone formation shifts to a net bone loss results in the development of osteoporosis in both men and women. In this review, we focus on our current understanding of the effects of vitamin K2 on bone cells and its role in prevention and treatment of osteoporosis.

Magnesium/Calcium Ratio in Serum Predicts Periodontitis and Tooth Loss in a 5-Year Follow-up

In the cross-sectional Study of Health in Pomerania (SHIP-0), subjects with an adequate magnesium supply had a lower risk of periodontal disease and more teeth than those with low magnesium levels. The authors analyzed 5-y follow-up data (SHIP-1) to determine whether the baseline magnesium levels had a long-term effect on attachment level and number of teeth lost. Of the participants examined dentally in the baseline study, 3,300 (75%) were examined for progression or recession of periodontal attachment level after 5 y. For 2,432 subjects, the authors related the outcome variables of periodontal attachment level and tooth loss to baseline characteristics, especially serum magnesium and calcium concentrations, as well as systemic markers of inflammation. The progression of periodontitis was associated with the magnesium/calcium (Mg/Ca) ratio at baseline in a dose-dependent manner. Progression of mean attachment loss was prevented in the upper quartile of the Mg/Ca ratio ( P < 0.001) with antagonistic effects of magnesium and calcium irrespective of inflammatory state. With respect to tooth loss, Mg/Ca exerted dimorphic effects. In inflammatory states as indicated by high C-reactive protein (>3 mg/L), tooth loss was prevented in subjects with high Mg/Ca ratio (incidence rate ratio = 0.60, 95% confidence interval: 0.45 to 0.80, P = 0.001), but the contrary was observed in subjects with low C-reactive protein levels (incidence rate ratio = 1.14, 95% confidence interval: 0.97 to 1.34, NS). Similar results were observed with stratifying the regression on tooth loss by interleukin 6 or fibrinogen threshold. An adequate magnesium serum level and Mg/Ca balance may prevent progression of attachment level and tooth loss, especially in inflammatory states. Knowledge Transfer Statement: The results of this study present evidence that an adequate magnesium supply may be important in the prevention of periodontal diseases and future tooth loss. A diet high in magnesium could improve periodontal health, notwithstanding its beneficial effects on systemic disease. In populations with a high prevalence of hypomagnesemia, additional intake of supplements is advisable.

Two-stage comprehensive evaluation of genetic susceptibility of common variants in FBXO38, AP3B2 and WHAMM to severe chronic periodontitis

Chronic periodontitis is an oral disorder characterized with gingival inflammation and bone destruction. As the sixth-most prevalent condition affecting more than 743 million people around the world, it is classified as one of the seven destructive oral disorders. Early genetic epidemiological evidence indicated a major role for genetics in periodontal disease development. In this study, we conducted a two-stage comprehensive evaluation of the genetic susceptibility of FBXO38, AP3B2 and WHAMM with the diagnosis of severe chronic periodontitis. A total of 5,065 study subjects from the Han Chinese population consisting of 1,264 cases and 3,801 healthy controls were recruited, and 65 single nucleotide markers related to the three candidate genes were genotyped to investigate the susceptibility of patients with these polymorphisms to severe chronic periodontitis. To increase the coverage of genetic markers, we implemented imputation techniques to extend the number of tested makers to 416. Single marker and haplotype-based analyses were performed, and significant results were obtained for FBXO38 (rs10043775, P = 0.0009) and AP3B2 (rs11631963-rs11637433, CA, P = 9.98 × 10(-5); rs1864699-rs2099259-rs2278355, ATC, P = 3.84 × 10(-8)). Our findings provide direct evidence for the association of FBXO38 and AP3B2 with severe chronic periodontitis in the Han Chinese population.

Risk of Periodontal Diseases in Patients With Chronic Obstructive Pulmonary Disease: A Nationwide Population-based Cohort Study

Several studies have reported an association between chronic obstructive pulmonary disease (COPD) and periodontal diseases. However, a large-scale population-based cohort study was previously absent from the literature. Therefore, we evaluated the risk of periodontal diseases in patients with COPD in a nationwide population.From the National Health Insurance claims data of Taiwan, we identified 22,332 patients with COPD who were newly diagnosed during 2000 to 2010. For each case, two individuals without COPD were randomly selected and frequency matched by age, sex, and diagnosis year. Both groups were followed up till the end of 2011.The overall incidence of periodontal diseases was 1.19-fold greater in the COPD group than in the comparison group (32.2 vs 26.4 per 1000 person-years; 95% confidence interval [CI] 1.15-1.24). Compared with non-COPD patients, the adjusted hazard ratios of patients with COPD increased with the number of emergency room visits (from 1.14 [95% CI 1.10-1.19] to 5.09 [95% CI 4.53-5.72]) and admissions (from 1.15 [95% CI 1.10-1.20] to 3.17 [95% CI 2.81-3.57]). In addition, the adjusted hazard ratios of patients with COPD treated with inhaled corticosteroids (1.22, 95% CI 1.11-1.34) and systemic corticosteroids (1.15, 95% CI 1.07-1.23) were significantly higher than those of patients not treated with corticosteroids.Patient with COPD are at a higher risk of developing periodontal diseases than the general population. Our results also support that the risk of periodontal diseases is proportional to COPD control. In addition, patients who receive corticosteroid treatment are at a higher risk of developing periodontal diseases.

Association between periodontal disease and osteoporosis by gender: a nationwide population-based cohort study

Periodontitis and osteoporosis are primary concerns in public health and clinical management. The aim of this study was to investigate the association between periodontitis and osteoporosis by gender.Data were retrieved from the National Health Insurance Research Database, Taiwan. A diagnosis of periodontitis was defined on the basis of subgingival curettage, periodontal flap operation, and gingivectomy (excluding those with restorative or aesthetic indications). Multiple logistic regression was used for analysis. After adjusting for age, sex, income, and geographical region, there was a significant association between periodontitis and osteoporosis among women (odds ratio: 1.96; 95% confidence interval 1.17-3.26). The association between periodontitis and osteoporosis was significant among women.

Oral health care in children with haemophilia in Helsinki, Finland

BACKGROUND

The bleeding tendency and fear of bleeds may have a negative effect on preventive dental care of patients with haemophilia both at home and at dental appointments.

AIM

To describe the clinical practice of dental care in children with haemophilia in Helsinki, Finland.

METHODS

This study evaluated retrospectively the medical records of 28 paediatric patients with haemophilia (aged 5.3-17.4 years) from dental visits during 2009-2010. Decayed, missing and filled teeth in the primary (dmft) and permanent dentition (DMFT), Community Periodontal Index (CPI), signs of developmental dental defects in enamel and the number of preventive and restorative procedures were gathered. Dmft + DMFT scores were compared with those of 17,079 non-haemophiliac boys. The Mann-Whitney U-test was used to compare the data between the groups of different severity of haemophilia.

RESULTS

The median number of dental visits per patient was three (range 1-11). Twenty-two patients (79 %) had dmft + DMFT-scores within the 95 % reference range for age. None of the children had a CPI >2. Twelve (43 %) patients had developmental enamel defects. Half had received restorative dental care and three out of four preventive procedures.

CONCLUSIONS

Dental care during hospital visits in children with haemophilia may enhance confidence in the preventive dental care and help minimise bleeding during dental procedures.

Diverse osteoclastogenesis of bone marrow from mandible versus long bone

BACKGROUND

Mandibles (MB) and maxillae possess unique metabolic and functional properties and demonstrate discrete responses to homeostatic, mechanical, hormonal, and developmental stimuli. Osteogenic potential of bone marrow stromal cells (BMSCs) differs between MB versus long bones (LB). Furthermore, MB- versus LB-derived osteoclasts (OCs) have disparate functional properties. This study explores the osteoclastogenic potential of rat MB versus LB marrow in vitro and in vivo under basal and stimulated conditions.

METHODS

Bone marrow from rat MB and LB was cultured in osteoblastic or osteoclastic differentiation media. Tartrate-resistant acid phosphatase (TRAP) staining, resorption pit assays, and real-time polymerase chain reaction were performed. Additionally, osmotic mini-pumps were implanted in animals, mandibles and tibiae were isolated, and multinucleated cells (MNCs) were measured.

RESULTS

MB versus LB marrow cultures that were differentiated with receptor activator of nuclear factor-κB ligand (RANKL) and macrophage colony-stimulating factor produced more TRAP(+) MNCs and greater resorptive area. To explore MB versus LB BMSC-supported osteoclastogenesis, confluent BMSCs were cultured with parathyroid hormone (PTH), 1,25-dihydroxyvitamin D3 (1,25D3), or PTH+1,25D3. 1,25D3- or PTH+1,25D3-treated LB BMSCs expressed significantly higher RANKL and lower osteoprotegerin (OPG) mRNA and increased RANKL:OPG ratio. When whole marrow was cultured with PTH+1,25D3, more TRAP(+) MNCs were seen in LB versus MB cultures. Ultimately, rats were infused with PTH+1,25D3, and MB versus tibia MNCs were measured. Hormonal stimulation increased osteoclastogenesis in both MB and tibiae. However, higher TRAP(+) MNC numbers were observed in tibiae versus MB under basal and hormonal stimulation.

CONCLUSION

Collectively, these data illustrate differences of both osteoclastogenic potential and OC numbers of MB versus LB marrow.

Periodontal disease and risk of preeclampsia: a meta-analysis of observational studies

Background

Many epidemiological studies have found a positive association between periodontal disease (PD) and the risk of preeclampsia, but the magnitude of this association varies and independent studies have reported conflicting findings. We performed a meta-analysis to ascertain the relationship between PD and preeclampsia.

Methods

The PubMed database was searched up to January 12, 2013, for relevant observational studies on an association between PD and the risk of preeclampsia. Data were extracted and analyzed independently by two authors. The meta-analysis was performed using comprehensive meta-analysis software.

Results

Thirteen observational case-control studies and two cohort studies, involving 1089 preeclampsia patients, were identified. Based on a random-effects meta-analysis, a significant association between PD and preeclampsia was identified (odds ratio = 2.79, 95% confidence interval CI, 2.01–3.01, P<0.0001).

Conclusions

Although the causality remains unclear, the association between PD and preeclampsia may reflect the induction of PD by the preeclamptic state, or it may be part of an overall exaggerated inflammatory response to pregnancy. Larger randomized controlled trials with preeclampsia as the primary outcome and pathophysiological studies are required to explore causality and to dissect the biological mechanisms involved.

Do patients with osteoporosis have an increased prevalence of periodontal disease? A cross-sectional study

The study examined if women with osteoporosis were at increased risk of periodontal disease. Three hundred eighty females aged 45-65 years with recent dual-energy X-ray absorptiometry (DXA) scans of the spine and proximal femur agreed to a dental examination. No association was established between the presence of severe periodontal disease and osteoporosis.

INTRODUCTION

The purpose of this study is to determine whether patients with osteoporosis have an increased severity and extent of periodontal disease, taking full account of confounding factors.

METHODS

Volunteer dentate women (45-65 years), who had undergone recent DXA of the femur and lumbar spine, received a clinical examination of their periodontal tissues by a single trained operator who was blind to the subject's osteoporosis status. Clinical examinations were performed within 6 months of the DXA. Basic Periodontal Examination score, gingival bleeding score, periodontal pocket depth, recession and calculus were the periodontal outcome measures. Potential confounding factors were recorded. Logistic regression was performed for the dichotomous outcome measure of severe periodontal disease (present or absent) with osteoporotic status, adjusting for confounding factors.

RESULTS

There were 380 dentate participants for whom DXA data were available. Of these, 98 had osteoporosis. When compared with osteoporotic subjects, those with normal bone mineral density were significantly younger (p = 0.01), had a higher body mass index (p = 0.03) and had more teeth (p = 0.01). The prevalence of severe periodontal disease in the sample was 39 %. The unadjusted odds ratio for the association between osteoporosis and severe periodontal disease was 1.21 (0.76 to 1.93). The adjusted odds ratio analysis including other covariates (age, smoking, hormone replacement therapy, alcohol) was 0.99 (0.61 to 1.61).

CONCLUSION

No association was established between the presence of severe periodontal disease and osteoporosis.

Assessment of alveolar bone mineral density as a predictor of lumbar fracture probability

INTRODUCTION

Osteoporosis and tooth loss have been linked with advancing age, but no clear relationship between these conditions has been proven. Several studies of bone mineral density measurements of the jaw and spine have shown similarities in their rate of age-related deterioration. Thus, measurements of jawbone density may predict lumbar vertebral bone density. Using jawbone density as a proxy marker would circumvent the need for lumbar bone measurements and facilitate prediction of osteoporotic spinal fracture susceptibility at dental clinics. We aimed to characterize the correlation between bone density in the jaw and spine and the incidence of osteoporotic spinal fractures.

METHODS

We used computerized radiogrammetry to measure alveolar bone mineral density (al-BMD) and dual-energy X-ray absorptiometry to measure lumbar bone mineral density (L-BMD). L-BMD and al-BMD in 30 female patients (average age: 59 ± 5 years) were correlated with various patient attributes. Statistical analysis included area under the curve (AUC) and probability of asymptomatic significance (PAS) in a receiver operating characteristic curve. The predictive strength of L-BMD T-scores (L-BMD[T]) and al-BMD measurements for fracture occurrence was then compared using multivariate analysis with category weight scoring.

RESULTS

L-BMD and al-BMD were significantly correlated with age, years since menopause, and alveolar bone thickness. Both were also negatively correlated with fracture incidence. Category weight scores were -0.275 for a L-BMD(T) <80%; +0.183 for a L-BMD(T) ≥ 80%; -0.860 for al-BMD <84.9 (brightness); and +0.860 for al-BMD ≥ 84.9. AUC and PAS analyses suggested that al-BMD had a higher association with fracture occurrence than L-BMD.

CONCLUSIONS

Our results suggest the possible association between al-BMD and vertebral fracture risk. Assessment of alveolar bone density may be useful in patients receiving routine dental exams to monitor the clinical picture and the potential course of osteoporosis in patients who may be at a higher risk of developing osteoporosis.

Periodontal disease and risk of chronic obstructive pulmonary disease: a meta-analysis of observational studies

BACKGROUND

Many epidemiological studies have found a positive association between periodontal disease (PD) and risk of chronic obstructive pulmonary disease (COPD), but this association is varied and even contradictory among studies. We performed a meta-analysis to ascertain the relationship between PD and COPD.

METHODS

PubMed and Embase database were searched up to January 10, 2012, for relevant observational studies on the association between PD and risk of COPD. Data from the studies selected were extracted and analyzed independently by two authors. The meta-analysis was performed using the Comprehensive Meta-Analysis software.

RESULTS

Fourteen observational studies (one nested case-control, eight case-control, and five cross-sectional) involving 3,988 COPD patients were yielded. Based on random-effects meta-analysis, a significant association between PD and COPD was identified (odds ratio = 2.08, 95% confidence interval = 1.48-2.91; P<0.001), with sensitivity analysis showing that the result was robust. Subgroups analyses according to study design, ethnicity, assessment of PD/COPD, and adjusted/unadjusted odds ratios also revealed a significant association. Publication bias was detected.

CONCLUSIONS

Based on current evidence, PD is a significant and independent risk factor of COPD. However, whether a causal relationships exists remains unclear. Morever, we suggest performing randomized controlled trails to explore whether periodontal interventions are beneficial in regulating COPD pathogenesis and progression.

Potential implications of adjuvant endocrine therapy for the oral health of postmenopausal women with breast cancer

Current adjuvant treatment modalities for breast cancer that express the estrogen receptor or progesterone receptor include adjuvant anti-estrogen therapies, and tamoxifen and aromatase inhibitors. Bone, including the jaw, is an endocrine-sensitive organ, as are other oral structures. This review examines the potential links between adjuvant anti-estrogen treatments in postmenopausal women with hormone receptor positive breast cancer and oral health. A search of PubMed, EMBASE, CENTRAL, and the Web of Knowledge was conducted using combinations of key terms "breast," "cancer," "neoplasm," "Tamoxifen," "Aromatase Inhibitor," "chemotherapy," "hormone therapy," "alveolar bone loss," "postmenopausal bone loss," "estrogen," "SERM," "hormone replacement therapy," and "quality of life." We selected articles published in peer-reviewed journals in the English. The authors found no studies reporting on periodontal diseases, alveolar bone loss, oral health, or oral health-related quality of life in association with anti-estrogen breast cancer treatments in postmenopausal women. Periodontal diseases, alveolar bone density, tooth loss, and conditions of the soft tissues of the mouth have all been associated with menopausal status supporting the hypothesis that the soft tissues and bone of the oral cavity could be negatively affected by anti-estrogen therapy. As a conclusion, the impact of adjuvant endocrine breast cancer therapy on the oral health of postmenopausal women is undefined. The structures of the oral cavity are influenced by estrogen; therefore, anti-estrogen therapies may carry the risk of oral toxicities. Oral health care for breast cancer patients is an important but understudied aspect of cancer survivorship.

[Osteoporosis and oral diseases]

Osteoporosis is a major cause of fractures in elderly women. Bone densitometry is used in order to detect osteoporosis. It has been observed can also be analyzed in the jawbone. The osteoporosis may be associated with resorption of the residual ridge, periodontitis and tooth loss; also the same treatments can affect the jaws. A search was carried out in the Medline-Pubmed database in order to search the association between osteoporosis and oral diseases over the past 5 years. Forty-two articles were obtained after the selection process. The authors stated that: in reference to periodontal disease the results are conflicting, but there seems to be a higher prevalence of the disease and tooth loss and resorption of the crest. Oral bisphosphonates have little risk of causing osteonecrosis, and there is no relationship in the dental implant failure among patients taking bisphosphonates. There is no clear scientific evidence that could link osteoporosis and oral diseases.

Premature osteoblast clustering by enamel matrix proteins induces osteoblast differentiation through up-regulation of connexin 43 and N-cadherin

In recent years, enamel matrix derivative (EMD) has garnered much interest in the dental field for its apparent bioactivity that stimulates regeneration of periodontal tissues including periodontal ligament, cementum and alveolar bone. Despite its widespread use, the underlying cellular mechanisms remain unclear and an understanding of its biological interactions could identify new strategies for tissue engineering. Previous in vitro research has demonstrated that EMD promotes premature osteoblast clustering at early time points. The aim of the present study was to evaluate the influence of cell clustering on vital osteoblast cell-cell communication and adhesion molecules, connexin 43 (cx43) and N-cadherin (N-cad) as assessed by immunofluorescence imaging, real-time PCR and Western blot analysis. In addition, differentiation markers of osteoblasts were quantified using alkaline phosphatase, osteocalcin and von Kossa staining. EMD significantly increased the expression of connexin 43 and N-cadherin at early time points ranging from 2 to 5 days. Protein expression was localized to cell membranes when compared to control groups. Alkaline phosphatase activity was also significantly increased on EMD-coated samples at 3, 5 and 7 days post seeding. Interestingly, higher activity was localized to cell cluster regions. There was a 3 fold increase in osteocalcin and bone sialoprotein mRNA levels for osteoblasts cultured on EMD-coated culture dishes. Moreover, EMD significantly increased extracellular mineral deposition in cell clusters as assessed through von Kossa staining at 5, 7, 10 and 14 days post seeding. We conclude that EMD up-regulates the expression of vital osteoblast cell-cell communication and adhesion molecules, which enhances the differentiation and mineralization activity of osteoblasts. These findings provide further support for the clinical evidence that EMD increases the speed and quality of new bone formation in vivo.