Assessment of Parathyroid Hormone Serum Level as a Predictor for Bone Condition Around Dental Implants

PURPOSE

The aim of this prospective study was to evaluate parathyroid hormone serum level as a potential single factor of bone metabolism around dental implants.

MATERIALS AND METHODS

Parathyroid hormone levels were measured before implantation. Intraoral digital radiographs were taken in standardized conditions in all cases: immediately after implantation, immediately after functional loading, and 3, 6, 9, 12, 18, and 24 months after functional loading. The next phase was to align all radiographs geometrically. Two regions of interest were marked in the bone image: one in the implant neck region and another in the periapical region. Next, the entropy of the microarchitecture of the bone image was calculated, and an analysis of simple regression was performed.

RESULTS

The prospective study included 107 patients of both sexes in the age range of 17 to 67 years (mean ± SD: 45.53 ± 12.1 years). A significant relationship was observed between higher levels of parathyroid hormone (but still in the normal range) and the decrease of textural entropy in the alveolar ridge bone at 3, 6, 12, and 18 months after functional loading. However, in the periods immediately after implantation, immediately after functional loading, and 9 and 24 months after functional loading, the relationship was not statistically significant.

CONCLUSION

Assessment of the parathyroid hormone serum level can be considered a useful method to predict bone condition around a dental implant, but not as a single factor.

The Effect of Cyclosporin A on Alveolar Bone in Rats Subjected to Experimental Periodontal Disease

Cyclosporine A (CsA), broadly used in organ transplantation, may contribute to pathogenesis of osteoporosis. The aim of this study was to investigate the effects of CsA on alveolar bone in rats subjected or not to experimental periodontal disease using biochemical, radiographic, and histometric analysis. Forty Wistar rats were divided into 4 equal groups: Group I (Control), Group II (CsA was injected subcutaneously in a daily dose of 10 mg/kg), Group III (Ligature was placed around the mandibular molars), Group IV (Ligature+CsA). After 60 days, rats were decapitated, serum alkaline phosphatase and calcium levels were measured. Radiographic-alveolar bone loss (ABL), histometric-ABL, and percentage of new alveolar bone formation (NABF%) were determined on mandibular molars. Significant increase in serum alkaline phosphatase levels ( p < 0.001), no significant difference in calcium levels were observed ( p > 0.05) in Group IV compared to Group III. Radiographic and histometric-ABL were significantly less ( p < 0.001), NABF% was significantly greater ( p < 0.05) in Group IV than in Group III. No significant difference in any of the parameters between Group II and Group I was found. It can be concluded that in the presence of periodontal disease, CsA treatment may bring out an imbalance in the alveolar bone homeostasis by decreasing resorption and stimulating formation of alveolar bone in rats.

25-hydroxyvitamin D3 ameliorates periodontitis by modulating the expression of inflammation-associated factors in diabetic mice

Periodontitis is a complication of diabetes mellitus, and the two diseases are highly associated with the dysfunction of inflammatory mediators. 25-hydroxyvitamin D(3) (25(OH)D(3)) plays a pivotal role in inflammatory modulation, but little is known about its effects on the progression of diabetic periodontitis and the underlying mechanism. In this paper, we showed that 25(OH)D(3) ameliorated experimental periodontitis in diabetic mice. The intraperitoneal administration of 25(OH)D(3) to streptozotocin-induced diabetic mice reduced fasting glucose and serum TNF-α levels, leading to decreased alveolar bone loss. Western blot analyses of gingival epithelia showed that vitamin D receptor (VDR) and protein tyrosine phosphatase N2 (PTPN2) were upregulated, while the expression of NF-κB and the phosphorylation of Janus family kinase 1 (JAK1) were attenuated upon 25(OH)D(3) treatment. These data may provide an explanation for the therapeutic benefits and anti-inflammatory effects of 25(OH)D(3). Our findings should have important implications for the clinical therapy of diabetic periodontitis.

Platelet-activating factor levels of serum and gingival crevicular fluid in nonsmoking patients with periodontitis and/or coronary heart disease

The purpose of the present study was to investigate systemic and local levels of platelet-activating factor (PAF), a potent proinflammatory mediator implicated in cardiovascular pathophysiology in adult nonsmoking patients with periodontitis with or without coronary heart disease (CHD). Eighty-seven volunteers, 25 periodontitis patients, 19 periodontitis with CHD patients, 19 CHD patients, and 24 healthy controls were included, and periodontal conditions were assessed. Gingival crevicular fluid (GCF) and venous blood were collected, and PAF levels were measured by enzyme-linked immunosorbent assay. PAF levels in serum (303.3 ± 204 pg/ml) and in GCF (26.3 ± 6 pg/μl) of the periodontitis group with CHD, the periodontitis group (serum, 302.4 ± 241 pg/ml and GCF, 26.3 ± 8 pg/μl) and the CHD group (serum, 284.7 ± 192 pg/ml and GCF, 20.8 ± 6 pg/μl) were significantly higher than the healthy control group (serum, 65.4 ± 35 pg/ml and GCF, 7.7 ± 3 pg/μl; p < 0.05). In summary, the present study could demonstrate that in patients with periodontitis, the inflammatory mediator PAF is released into serum at least in the same range as for patients with coronary heart disease. However, no additive effects were seen when both conditions were present.

Intermittent therapy with 1,25 vitamin D and calcitonin prevents cyclosporin-induced alveolar bone loss in rats

Bone loss associated with cyclosporin A (CsA) therapy can result in serious morbidity to patients. Intermittent administration of 1,25 Vitamin D and calcitonin reduces osteopenia in a murine model of postmenopausal osteoporosis. The purpose of this study was to evaluate the effects of this therapeutic approach on CsA-induced alveolar bone loss in rats. Forty male Wistar rats were allocated to four experimental groups according to the treatment received during 8 weeks: (1) CsA (10 mg/kg/day, s.c.); (2) 1,25 Vitamin D (2 microg/kg, p.o.; in weeks 1, 3, 5, and 7) plus calcitonin (2 microg/kg, i.p.; in weeks 2, 4, 6, and 8); (3) CsA concurrently with intermittent 1,25 Vitamin D and calcitonin administration; and (4) the control treatment group (vehicle). At the end of the 8-week treatment period, serum concentrations of bone-specific alkaline phosphatase, tartrate-resistant acid phosphatase (TRAP-5b), osteocalcin, interleukin (IL)-1 beta, IL-6, and tumor necrosis factor alpha (TNF-alpha) were measured and an analysis of bone volume, bone surface, number of osteoblasts, and osteoclasts was performed. CsA administration resulted in significant alveolar bone resorption, as assessed by a lower bone volume and an increased number of osteoclasts, and increased serum bone-specific alkaline phosphatase, TRAP-5b, IL-1 beta, IL-6, and TNF-alpha concentrations. The intermittent administration of calcitriol and calcitonin prevented the CsA-induced osteopenic changes and the increased serum concentrations of TRAP-5b and inflammatory cytokines. Intermittent calcitriol/calcitonin therapy prevents CsA-induced alveolar bone loss in rats and normalizes the production of associated inflammatory mediators.

Evaluation of estrogen receptor and circulating estradiol levels in pre- and postmenopausal women with periodontal disease

Although the presence of estrogen receptors (ERs) in the gingival tissues has been confirmed, there is as yet insufficient literature regarding its expression in periodontal health and disease. Gingival samples were collected from 40 subjects who were divided into four groups. (Group A, premenopausal health; Group B, premenopausal periodontitis; Group C, postmenopausal health; Group D, postmenopausal periodontitis). ERs were identified with an anti-ER monoclonal antibody (Bio Genex). Circulating estradiol (E2) levels were estimated using the Genix E2 EIA commercial kit. An inverse relationship between E2 and ER levels in gingiva was observed in all the samples. There was significantly reduced expression of ERs in the gingiva of subjects with chronic periodontitis when compared to those with healthy periodontium in the postmenopausal group.

Lipid peroxidation levels and total oxidant status in serum, saliva and gingival crevicular fluid in patients with chronic periodontitis

OBJECTIVES

Increased levels of reactive oxygen species lead to oxidative stress. Recent data suggest increased lipid peroxidation (LPO) levels and oxidative stress in periodontitis. Malondialdehyde (MDA), a significant LPO product, increases in oxidative stress. In this study, MDA levels and total oxidant status (TOS) in serum, saliva and gingival crevicular fluid (GCF) were investigated in patients with chronic periodontitis (CP).

MATERIALS AND METHODS

Thirty-six CP patients and 28 periodontally healthy controls were included in the study. Following clinical measurements and samplings, MDA and TOS levels were measured by high-performance liquid chromatography and a novel automatic colorimetric method, respectively.

RESULTS

While the saliva and GCF MDA levels, and serum, saliva and GCF TOS values were significantly higher in the CP group than the control group (p<0.05), no significant difference in serum MDA levels was found (p>0.05). Strong positive correlations were observed between periodontal parameters and MDA and TOS levels (p<0.05).

CONCLUSIONS

The results revealed that LPO significantly increased locally in the periodontal pocket/oral environment, while TOS displayed both systemic and local increases in periodontitis. The findings suggest that increased LPO and TOS may play an important role in the pathology of periodontitis, and are closely related to the clinical periodontal status.

Polymorphisms in the CD14 and IL-6 genes associated with periodontal disease

AIM

To compare the frequencies of cytokine and receptor molecule genotypes in patients with chronic periodontitis with the corresponding frequencies in a reference population and to study the relationship between periodontal disease severity and polymorphisms in the studied genes.

SUBJECTS AND METHODS

CD14, IL-6, TNF-alpha, IL-10, IL-1alpha, IL-1beta, and TLR-4 polymorphisms of 51 periodontitis patients were studied using polymerase chain reaction. The genotype frequencies in the periodontitis patients and a reference population (n=178) were compared. Probing pocket depth (PD), periodontal attachment level (AL), and alveolar bone level (BL) were related to the genotypes.

RESULTS

No statistically significant differences could be found between the frequencies of the cytokine genotypes in the periodontitis patients and in the reference group. The extent of periodontal disease was higher in subjects with the T-containing genotype of CD14(-260) and the GG genotype of IL-6(-174) when compared with the extent in the rest of the group. Subjects carrying the composite genotype of the above two were most severely affected by periodontal disease.

CONCLUSION

According to the present results, an evident association exists between the carriage of the T-containing genotype of CD14(-260) and the GG genotype of IL-6(-174) and the extent periodontal disease.

Autoantibodies directed to extracellular matrix components in patients with different clinical forms of periodontitis

BACKGROUND

Periodontal disease occurs in different clinical forms, from mild and easily controllable to more aggressive inflammatory manifestations, with difficult clinical or surgical control. There is evidence that a local autoimmune reaction may participate in the onset and persistence of the aggressive forms of periodontal disease. As the underlying mechanism in this process is not fully understood, we decided to investigate whether patients bearing this form of disease presented higher levels of antibodies directed to extracellular matrix (ECM) components such as type I collagen, fibronectin, and laminin.

METHODS

Three groups of patients were selected by clinical criteria: 22 subjects with aggressive periodontitis (AgP) = group A; 18 subjects with chronic periodontitis (CP) = group B; and 10 healthy (H) volunteers without periodontal disease = group C. Autoantibody levels were evaluated in the sera of these patients using the enzyme-linked immunosorbent assay (ELISA) method.

RESULTS

The levels of autoantibodies directed to ECM components (type I collagen, fibronectin and laminin) in the sera of patients with AgP and CP were shown to be statistically different (P <0.05).

CONCLUSIONS

Although the present findings suggest an involvement of autoantibodies directed to ECM components per se in the pathogeny of certain types of periodontal disease, the available data do not support the classification of the lesions as autoimmune. Nevertheless, the findings open a possibility for the development of an additional method for a differential diagnosis of the aggressive forms of periodontal disease.

The role of psychoneuroimmune interactions in the pathogenesis of ligature-induced periodontal disease in Wistar rats

The aim of the present study was to determine the role of chronic stress in the pathogenesis of ligature-induced periodontal disease in rats. Fifty-three Wistar rats were randomly assigned to 4 experimental groups: 1--ligature; 2--ligature + stress; 3--stress only; 4--control. After 30 days the animals were sacrificed, blood samples were collected and histological sections were made for histometric analysis. The stress parameters evaluated were weight of thymus, spleen, adrenal glands and plasma glucocorticoid levels. Analysis of adrenal glands showed statistically significant differences between stressed and non-stressed groups (one-way ANOVA, p < 0.05). Plasma glucocorticoid levels were higher in Group 3 and lower in Group 2 (81.1 nmol/I versus 62.5 nmol/l, p < 0.05). Histometric measurements from the bone crest and from the first attached fiber were taken for all groups and for Groups 1 and 2 for the sites with and without ligatures. The ligature sites always displayed higher mean values than non-ligated sites (paired sample t test, p < 0.05). No statistically significant differences were observed between Groups 1 and 2 with regard to the ligated sites. However, differences were observed between Groups 1 and 2 in histometric bone levels in the non-ligated sites (mean values of 0.81 and 0.55 mm, respectively, p < 0.05). It may be concluded that stress can have a possible role in the activation of the hypothalamus-pituitary-adrenal (HPA) axis, with different levels of glucocorticoid release.

Periodontitis and plasma C-reactive protein during pregnancy

BACKGROUND

Periodontitis has been associated with increased risk of adverse pregnancy outcomes and elevated C-reactive protein (CRP) concentrations in non-pregnant adults. We examined the relationship between periodontitis and CRP among women who provided dental radiographs and had blood collected during early pregnancy, excluding smokers and diabetic patients.

METHODS

From Project Viva, an ongoing cohort study, we measured plasma CRP in 35 subjects with periodontitis (i.e., at least one site with > or =3 mm of alveolar bone loss) and a random sample of 66 periodontally healthy subjects matched on age and race/ethnicity. We performed linear regression analysis with log-transformed CRP levels as the outcome.

RESULTS

The mean (+/- SE) CRP level was 65% higher (95% confidence interval: -2%, 180%; P = 0.06) in women with periodontitis (2.46 +/- 0.52 mg/l) than in controls (1.49 +/- 0.22 mg/l), adjusting for factors related to CRP levels, including age, race/ethnicity, pre-pregnancy body mass index, alcohol intake, education, income, and gestational age at blood collection.

CONCLUSIONS

These findings suggest that periodontitis may increase CRP levels in pregnancy. CRP could potentially mediate the association of periodontitis with adverse pregnancy outcomes.

Dietary supplementation of omega-3 fatty acid and circulating levels of interleukin-1beta, osteocalcin, and C-reactive protein in rats

BACKGROUND

In this study, we evaluated the effects of two different regimes of dietary supplementation of omega-3 fatty acid on serum levels of interleukin-1 beta (IL-1beta), osteocalcin (OC), and C-reactive protein (CRP) in experimental periodontitis.

METHODS

Experimental periodontitis was induced by repeated injections of Escherichia coli lipopolysaccharide (LPS). Thirty-nine adult male Sprague-Dawley rats were divided into four study groups as follows: an LPS positive control group; a saline (negative) control group; and two different groups with omega-3 fatty acid dietary supplementation, one in which we gave the supplement subsequent to disease induction (TO3) and the other in which the agent was started prior to and continued subsequent to LPS injections (P + TO3). In the TO3 group, omega-3 fatty acid administration was performed for 14 days following induction of experimental periodontitis. In the P + TO3 group, omega-3 fatty acid was given for 14 days prior to the start of LPS injections and was continued for another 14 days subsequent to the induction of experimental periodontitis. On day 15 of the first LPS injection, serum samples were obtained and rats were sacrificed. Serum samples were analyzed for IL-1beta, OC, and CRP concentrations by enzyme-linked immunosorbent assay. Defleshed jaws were analyzed morphometrically for alveolar bone loss. Data were evaluated statistically by non-parametric tests.

RESULTS

LPS injection resulted in statistically significantly more bone loss compared to the saline control group (P <0.05). None of the omega-3 fatty acid administration groups showed evidence that this fatty acid was effective in preventing LPS-induced alveolar bone loss. TO3 and P + TO3 groups revealed significantly higher IL-1beta and OC levels than the LPS group (P <0.05). The study groups exhibited no significant differences in the serum CRP levels.

CONCLUSIONS

Omega-3 fatty acid administration does not seem to influence circulating levels of CRP. The significantly increased serum OC level observed in both omega-3 fatty acid regimes is curious and could have an effect on bone turnover, as could the further significant increase in serum IL-1beta, which could counteract any osteoblastic induction by OC through promotion of osteoclast activity. The lack of a therapeutic benefit of omega-3 fatty acid in this study, despite the effects on OC and IL-1beta, is difficult to explain, and further studies are required to more fully assess the potential role of this fatty acid in periodontal treatment.

Effects of selective cyclooxygenase-2 inhibitor and omega-3 fatty acid on serum interleukin-1beta, osteocalcin, and C-reactive protein levels in rats

BACKGROUND

The aim of this study was to evaluate the effects of selective cyclooxygenase-2 inhibitor, celecoxib, and omega-3 fatty acid on serum levels of interleukin 1-beta (IL-1beta), osteocalcin (OC), and C-reactive protein (CRP) in experimental periodontitis.

METHODS

Experimental periodontitis in rats was induced by repeated injection of purified lipopolysaccharide (LPS) derived from Escherichia coli endotoxin. Forty-seven adult male Sprague-Dawley rats were divided into five study groups as follows: saline control, LPS, LPS + celecoxib, LPS + omega-3 fatty acid, and LPS + celecoxib + omega-3 fatty acid. Celecoxib and omega-3 fatty acid were given alone or in combination during 14 days of the experimental study period. At the end of the 2-week protocol, serum samples were obtained, and the rats were sacrificed. Serum samples were analyzed for IL-1beta, OC, and CRP concentrations by enzyme-linked immunosorbent assay. Defleshed jaws were analyzed morphometrically for alveolar bone loss. Data were evaluated statistically by non-parametric tests.

RESULTS

According to the morphometric measurements, the LPS and drug treatment groups showed significantly higher bone loss than the saline control group (P <0.05). Omega-3 fatty acid, both alone and in combination with celecoxib, revealed significantly higher IL-1beta levels than LPS and celecoxib groups (P <0.05). Individual and combined administration of celecoxib and omega-3 fatty acid significantly increased OC levels compared to the LPS group (P <0.05). There were no significant differences in serum CRP levels.

CONCLUSIONS

Celecoxib and/or omega-3 fatty acid administration does not significantly influence circulating levels of CRP. The significantly increased serum OC level observed after individual and combination administration suggests that celecoxib and omega-3 fatty acid may influence bone remodeling and thereby inhibit the progression of alveolar bone resorption. However, the failure to observe any significant inhibition of bone loss in celecoxib- and/or omega-3 fatty acid-treated rats compared to the LPS group suggests that their therapeutic effect may be reduced by other factors, such as increases in serum IL-1beta promoting osteoclast activity.

Oral health in patients on inhaled corticosteroid treatment

OBJECTIVE

The aim of this study was to investigate the effects of long-term inhaled corticosteroids on bone mineral density (BMD) of the mandible in relation with the tooth loss.

DESIGN

Cross sectional analytic study.

SUBJECTS AND METHODS

Patients (n = 30) with chronic obstructive pulmonary disease under inhaled corticosteroid therapy for at least 1 year were compared with sex- and age-matched healthy controls (n = 30). BMD of the mandible was measured by dual-energy X-ray absorptiometry. The clinical examination included recording the number of teeth present together with periodontal condition. Levels of serum osteocalcin, alkaline phosphatase, calcium, phosphorus and cortisol were also assessed.

RESULTS

BMD of the mandible in patients on corticosteroid treatment was significantly lower than that in the control group (P = 0.001). Patients under treatment had more missing teeth than the control group but the difference did not reach statistical significance. The two groups exhibited similar clinical parameters of periodontal condition. Significantly lower levels of osteocalcin (P < 0.0001), calcium (P = 0.004) and cortisol (P = 0.03) were observed in the patients on corticosteroid treatment.

CONCLUSION

Long-term use of inhaled corticosteroids may impair bone metabolism and lead to a marked decrease in the mandibular BMD.

The Influence of Surgical Treatment of Periodontal Disease on Selected Lymphocyte Subpopulations Important for Cellular and Humoral Immune Responses

BACKGROUND

Periodontal disease is a complex pathological process involving a wide spectrum of immunological reactions. The aim of the study was to evaluate the influence of surgical periodontal treatments on peripheral blood lymphocyte subpopulations.

METHODS

The study was performed in 40 generally healthy individuals diagnosed with generalized chronic periodontitis and a control group of 36 persons without periodontitis. Peripheral blood lymphocyte subpopulations were examined in both groups. Periodontal treatment was performed, using four different surgical procedures, in the study group. Peripheral blood lymphocyte subpopulations were re-evaluated again after 6 months.

RESULTS

Periodontal treatment resulted in a significant improvement of all measured clinical parameters, regardless of the surgical procedure. When evaluated in the study group as a whole, percentages of all but CD8+ T lymphocyte subpopulations were significantly different from the control group at baseline. Values in both groups after treatment were similar. Correlation analysis suggests a connection between the presence of CD25+ cells and selected clinical parameters of periodontal disease (probing depth and clinical attachment loss).

CONCLUSIONS

Statistically significant differences in the percentages of selected lymphocyte subpopulations in the peripheral blood of patients and healthy controls were found. The results suggest a correlation between selected clinical periodontal parameters and percentage of activated cells expressing the interleukin (IL)-2 receptor. Periodontal treatment resulted in significant improvement in the measured clinical and immunological parameters. It seems that the type of surgical treatment has little effect on the normalization of quantitative disturbances of the examined peripheral blood lymphocytes.

High-sensitivity serum C-reactive protein levels in subjects with or without myocardial infarction or periodontitis

BACKGROUND

Serum high-sensitivity C-reactive protein (hsC-rp) is a non-specific marker of inflammation. Elevated hsC-rp levels are found in subjects with cardiovascular diseases (CVDs). Periodontitis may influence hsC-rp levels.

OBJECTIVES

To assess periodontal status and hsC-rp serum levels in consecutive subjects hospitalized and diagnosed with acute myocardial infarction (AMI) (n=85) and in a group of carefully matched subjects (gender, age social, ethnic, and smoking habits) without clinical evidence of CVD (n=63).

METHODS

hsC-rp levels, other routine serum values, and clinical periodontal conditions were studied.

RESULTS

Subjects with AMI had higher hsC-rp levels than control subjects (p<0.001, Mann-Whitney U-test). The odds that subjects in the control group with periodontitis (30% or more sites with>4.0 mm loss of alveolar bone) had serum hsC-rp>1.8 mg/l was 1.5 (95% CI: 1.1-7.3, p<0.05). Stepwise linear regression analysis failed to include periodontal parameters in an explanatory model to hsC-rp values. Only the serum leucocyte (white blood cell (WBC)) counts were explanatory to hsC-rp values (beta standard coefficient=0.45, t=3.2, p<0.001). Serum WBC counts were significantly higher in control subjects with periodontitis (p<0.03) but not in subjects in the AMI group (p<0.57).

CONCLUSIONS

(1) As expected, elevated serum hsC-rp concentration and serum WBC counts are associated with acute coronary heart disease. (2) Elevated serum hsC-rp values are associated with radiographically defined periodontitis in subjects with no evidence of CVD. (3) Periodontal parameters are not explanatory to elevated serum hsC-rp values if serum WBC and low-density lipoprotein counts are included in the regression model.

Effect of lifestyle on periodontal disease status in diabetic patients

Lifestyle and socioeconomic status have been associated with the disease status of diabetic patients. However, there have been few reports on the relationship between these factors and the periodontal condition of diabetics. We assessed the association between disease status and lifestyle of diabetic patients and clinical features of advanced periodontitis such as deep probing depths and severe alveolar bone loss. Fifty-seven diabetic patients were examined in this study. Clinical assessment of probing pocket depth and radiographic alveolar bone loss was performed. Data regarding diabetic status and lifestyle of the diabetic patients were also recorded and statistically analysed by logistic regression. Drinking habits and high values of hemoglobin A1c (HbA1c) (>9.0%) were significantly associated with deep probing depth. The odds ratios (OR) of these factors were 7.72 (95% confidence interval (CI), 1.80 to 33.19), and 6.10 (95% CI = 1.23 to 30.25), respectively. Presence of complications such as retinopathy (OR = 8.86, 95% CI, 1.99 to 39.40), irascible behaviour (OR = 8.40, 95% CI = 1.33 to 53.17) and high value of HbA1c (OR = 4.94, 95% CI = 1.14 to 21.46) were significantly related to mean advanced alveolar bone loss. Only the high value of HbA1c (OR = 3.53, 95% CI = 1.06 to 11.73) was detected as a significant factor related to advanced periodontitis, characterised by more than 50% mean alveolar bone loss, or two or more teeth with probing depth greater than 6 mm. In conclusion, drinking habit and irascible behaviour are correlated with the periodontal disease condition of diabetic patients, in addition to a high value of HbA1c (>9.0%). Lifestyle and psychosocial stress may affect the periodontal disease status of diabetic patients.

[Therapeutic effect of aqueous-extract from a traditional Chinese medical herb Drynaria fortunei on rat experimental model of alveolar bone resorption]

OBJECTIVE

To establish a rat model of experimental alveolar bone resorption and understand the therapeutic effect of a traditional Chinese medical herb Drynaria fortunei (DFS) on the rats suffering from alveolar bone resorption.

METHOD

A SD rat model with experimental alveolar bone resorption was established by using injection with E. coli Lipopolysaccharide (E-LPS) in local tissue of the animals. A DFS preparation (DFS aqueous-extract) was extracted with distilled water. The modeled rats were administrated by perfusion with DFS aqueous-extract at a dosage of 15 g crude drug/kg once a day for 10, 20 and 30 d, respectively. The effects of DFS aqueous extract on experimental alveolar bone resorption were estimated by detections of serum alkali phosphate (ALP) activity, Ca2+ and osteocalcin (OC) levels, and TRAP stained osteoclast count, bone mineral density (BMD) measurement and HE stained histopathological examination of the tooth-periodontal samples.

RESULT

In comparison with the controls, BMD values of the alveolar bones at experimental tooth sites of the tested rats with DFS aqueous-extract for 10 d administration were obviously increased (P < 0.05). In the tooth-periodontal samples from the rats for 10 d administration, disappearance of the osteoclast, decrease of Howship's lacuna numbers and formation of new non-calcified bone-like matrix attached by osteoblasts in alveolar bone at the root furcation from most of the samples occurred. Similar examining results in the tooth-periodontal samples from the rats for 20 and 30 d administrations were obtained, respectively. However, no statistically significant differences of the serum ALP activity, Ca2+ and OC levels among the tested rats for 10-30 d treatment and the controls (P > 0.05) were found.

CONCLUSION

The DFS aqueous extract has exact therapeutic effect on rat experimental alveolar bone resorption through suppressing bone resorption and promoting bone regeneration. Serum ALP activity, Ca2+ and osteocalcin (OC) levels can not be used as the effective index for examining alveolar bone resorption and regeneration in animal models.

Effect of cyclosporin A on alveolar bone homeostasis in a rat periodontitis model

OBJECTIVES

The administration of cyclosporin A has been associated with significant bone loss and increased bone remodeling. The present investigation was designed to evaluate the effects of cyclosporin A on alveolar bone of rats subjected to experimental periodontitis, using serum, stereometric and radiographic analysis.

METHODS

Twenty-four rats were divided into one of the following groups with six animals each: group I, control rats; group II, in which the animals received a cotton ligature around the lower first molars; group III, in which the rats received a cotton ligature around the lower first molars and were treated with 10 mg/(kg body weight day) of cyclosporin A; group IV, in which the rats were treated with 10 mg/(kg body weight day) of cyclosporin A. At the end of experimental period, at 30 days, animals were killed and the serum calcium and alkaline phosphatase levels were measured in all groups. The distance from the alveolar bone crest to the cemento-enamel junction was measured radiographically for each mesial surface of the lower first molars of each rat. After histological processing, the stereological parameters: volume densities of multinucleated osteoclasts (V(o)), alveolar bone (V(b)), marrow (V(m)), and relation of eroded surface/bone surface (Es/Bs) were assessed at the mesial region of the alveolar bone.

RESULTS

Significant decreases in serum calcium were observed in those groups that received cyclosporin A therapy. No significant changes in serum alkaline phosphatase were observed. The therapy with cyclosporin A combined with the ligature placement decreased the V(b) and increased the V(o), V(m) and Es/Bs at the mesial surface of lower first molars. On the other hand, the radiographic data showed that cyclosporin A therapy diminished the alveolar bone loss at the mesial surface of the lower first molars.

CONCLUSIONS

Therefore, within the limits of this study, we suggest that cyclosporin A at immunosuppressive levels can bring about an imbalance in the alveolar bone homeostasis in rats. However, in the presence of inflammatory stimulation, the inhibition of the immune system by cyclosporin A may decrease the initial periodontal breakdown.

Association Between Alveolar Bone Loss and Elevated Serum C-Reactive Protein in Japanese Men

BACKGROUND

Moderate elevation of C-reactive protein (CRP) is thought to predict type 2 diabetes and cardiovascular disease (CVD), both of which are associated with periodontitis. Recent studies indicate that periodontal disease is associated with moderate elevation of CRP; however, the relationship between alveolar bone loss (ABL) and CRP elevation is unclear.

METHODS

A total of 179 Japanese men aged 50 to 54 years old, with at least 10 teeth, were examined as part of a comprehensive health examination before retirement from the Japan Self-Defense Force. ABL was measured at proximal sites of posterior teeth on a panoramic x-ray film. The relationship between the mean ratio of ABL to root length and serum CRP level and other variables was analyzed.

RESULTS

ABL was significantly correlated with serum CRP level (P = 0.008), alkaline phosphatase (P = 0.008), high-density lipoprotein (HDL) cholesterol (P = 0.04, inversely), white blood cell count (P < 0.001), erythrocyte sedimentation rate (P = 0.002), age (P = 0.03), and smoking history (P < 0.001). In a multiple logistic regression model adjusted for age, smoking history, systolic blood pressure, body-mass index, triglyceride, and HDL cholesterol, subjects in the highest tertile of ABL had an increased risk for CRP elevation > or = 1.3 mg/l (odds ratio [OR] = 8.20; 95% confidence interval [CI], 1.6 to 40.7; P = 0.01) when compared to the lowest tertile of ABL.

CONCLUSION

ABL around posterior teeth was associated with elevated CRP in Japanese men, suggesting an association between periodontal disease and increased risk of type 2 diabetes and CVD.

Alveolar bone loss associated with glucose tolerance in Japanese men

AIMS

Type 2 diabetes is known to affect alveolar bone loss (ABL). The purpose of this study was to examine whether impaired glucose tolerance (IGT) is associated with ABL, as is diabetes.

METHODS

A case-control study was performed with 664 Japanese men aged 46-57 years. Panoramic radiographs revealed 513 severe ABL cases, 22 moderate ABL cases, and 129 controls with good alveolar bone. Diabetes status was classified into normal glucose tolerance (NGT), impaired fasting glucose (IFG), IGT, and newly diagnosed diabetes according to the fasting plasma glucose and 75-g oral glucose tolerance test (OGTT). Diabetes under treatment was excluded. Odds ratios (ORs) and 95% confidence intervals (CIs) were obtained from ordinal logistic regression analysis. Statistical adjustment was made for total cholesterol, HDL-cholesterol, triglyceride, rank in the Self Defence Forces (SDF), cigarette-years, alcohol use, body mass index, previous 10 years' brushing habits and instrument use other than toothbrush, and history of periodontal treatment.

RESULTS

A significant, approximately three-fold increase in the crude OR (crude OR=3.28; 95% CI=1.16-9.27) and non-significant 2.6-fold increase in the adjusted OR (adjusted OR=2.55; 95% CI=0.86, 7.54) of ABL was observed among men with newly diagnosed Type 2 diabetes compared with the reference group (NGT combined with IFG). However, there was no association between IGT and ABL (adjusted OR=0.99; 95% CI=0.59,1.64).

CONCLUSIONS

Type 2 diabetes, but not IGT, was positively associated with ABL. Preventive maintenance against periodontitis is important in middle-aged men with diabetes.

Teeth with periodontal bone loss, cigarette smoking and plasma cotinine levels

The aim of the present study is to assess teeth with periodontal bone loss, cigarette smoking and plasma cotinine levels. We enrolled 120 untreated periodontal patients with chronic periodontitis into the study. The group comprised 48 men and 72 women, ranging in age from 21 to 75 years (mean age, 42.4 years). We divided the patients into five groups based on self-reported smoking status: (1) heavy smokers (n=35); (2) light smokers (n = 17); (3) recent former smokers (n = 8); (4) long-term former smokers (n = 17); (5) non-smokers (n = 43). We calculated packyear: (number of cigarette/day/20 x years) for all smokers. Smoking status was confirmed by measurement of plasma cotinine levels in 116 subjects. Periodontal disease was assessed on a full set of periapical radiographs. The number of teeth with bone loss was scored in four categories (no bone loss, light bone loss, moderate bone loss or serious bone loss) in all patients. The results demonstrated that plasma cotinine levels correlated significantly with the number of cigarettes smoked per day. Moreover, heavy smokers had fewer teeth with no bone loss (P < 0.001) and more teeth with moderate bone loss (P < 0.001) than non-smokers. In addition, we found a negative correlation between packyears and the number of teeth with no bone loss (P < 0.04) and a positive correlation between packyears and the number of teeth with light bone loss (P < 0.005). However, we found no correlation between plasma cotinine levels and the number of teeth with bone loss. These clinical findings suggest that cigarette smoking affects the number of teeth with or without periodontal bone loss, and this effect is related to the degree of smoking exposure.

Porphyromonas gingivalis-specific IgG subclass antibody levels as immunological risk indicators of periodontal bone loss

BACKGROUND

It has been well demonstrated a positive association between the magnitude of host antibody response and periodontal disease status. Previous studies also reported that Porphyromonas gingivalis-specific IgG subclass antibodies were elevated in sera from adult periodontitis patients. However, the rôle and the association of these IgG subclass antibodies to the development of periodontal diseases are poorly understood.

AIM

The aim of present investigation was to examine the relation of serum IgG subclass antibody levels and alveolar bone loss in treated and untreated periodontitis patients.

METHODS

Serum samples were taken from 20 treated and maintained periodontitis patients (SPT patients), 30 untreated patients and 19 periodontally healthy subjects. We determined the IgG subclass antibody titers to P. gingivalis whole cells using an enzyme-linked immunosorbent assay (ELISA). Subgingival plaque samples were taken from the mesio-buccal surface of 6 randomly selected teeth of SPT patients and evaluated for the presence of P. gingivalis by immunofluorescence microscopy. Clinical measurements were also taken including full mouth intraoral radiographs to measure interproximal alveolar bone loss at baseline (BLS1) and at a 5-year recall visit in the SPT patients (BLS2).

RESULTS

Our results indicated that both patient groups had detectable levels of IgG1, IgG2, and IgG4. Significantly higher IgG1 was observed in both patient groups compared to the healthy subjects. The untreated patients also exhibited significantly elevated IgG2 response (p<0.05). The mean IgG4 level of the SPT patients was significantly higher compared to the other subject group (p<0.05). A statistically significant positive correlation between IgG2 levels and changes in bone levels (DeltaBLS: BLS2-BLS1) was seen in the SPT patients (p<0.001). SPT patients with high IgG2 and low IgG4 showed greater bone loss than those with low IgG2 and high IgG4 (p<0.05), although the mean prevalence of P. gingivalis in the 2 groups did not differ significantly.

CONCLUSION

Our data suggest that the prolonged IgG2 response after periodontal treatment may be indicative of recurrent or persistent periodontal destruction.

Bisphosphonate inhibits alveolar bone resorption in experimentally-induced peri-implantitis in dogs

The purpose of this study was to determine the effect of bisphosphonate on alveolar bone resorption in experimentally-induced peri-implantitis in beagle dogs. Experimental peri-implantitis was induced by ligation around the abutments, 6 months after placement of a fixture. Pamidronate (0.6 mg/kg) was injected intramuscularly every 3 days into each of 5 dogs. Another 5 dogs served as the control group and were injected with saline only. Peripheral blood and urine samples were collected every week up to 12 weeks after placement of the ligature. Standard X-rays were taken every week. Urinary deoxypyridinoline (DPD) and serum osteocalcin (OC) were evaluated by ELISA as markers of alveolar bone remodeling. X-ray films were analyzed with a computer image analyzer. After 12 weeks, the bone level was measured after removal of the gingival flap. The distance between the top surface of the fixture and the fundus of the defect was significantly lower in the Pamidronate group (1.59+/-0.55 mm, mean+/-SD) than in the control group (2.41+/-0.48 mm). Bone density analyzed from the X-ray films was significantly higher in the bisphosphonate group (69.2+/-8.7%, mean+/-SD) than in the control group (50.3+/-12.8%) after 2 to 8 weeks compared with the baseline value (100%). OC and DPD levels fluctuated during the experimental period. These findings suggest that bisphosphonate inhibits the progression of alveolar bone resorption during ligature-induced peri-implantitis in dogs.

The association of cigarette smoking with alveolar bone loss in postmenopausal females

BACKGROUND, AIMS

The purpose of this 2-year longitudinal clinical study was to determine the impact of smoking on alveolar bone height and density changes in postmenopausal females.

METHODS

59 postmenopausal women completed this study, including 38 non-smokers and 21 smokers. All subjects had a history of periodontitis, participated in 3- to 4-month periodontal maintenance programs and were within 5 years of menopause at the study outset. 4 vertical bite-wing radiographs of posterior sextants were taken at baseline and 2-year visits. Radiographs were evaluated using computer-assisted densitometric image analysis (CADIA); changes in interproximal alveolar bone density and changes in alveolar bone height were determined. Relative clinical attachment levels (RCAL) and presence/absence of plaque and bleeding on probing were recorded.

RESULTS

Smokers exhibited a higher frequency of alveolar bone height loss (p<0.05) and crestal (p<0.03) and subcrestal (p<0.02) density loss relative to non-smokers. Smokers exhibited a trend (p<0.08) toward a higher frequency of > or =2.0 mm RCAL loss over the 2-year period. Plaque and bleeding on probing did not differ between smokers and non-smokers. A significant interaction, determined by repeated measures ANOVA, was noted between systemic bone mineral density (BMD) at the lumbar spine and smoking on alveolar bone density change (p<0.05). Only non-smoking patients with normal BMD realized a mean net gain in alveolar bone density; osteoporotic/osteopenic subjects (n=25) and smokers lost alveolar bone density.

CONCLUSION

Postmenopausal female smokers were more likely to lose alveolar bone height and density than non-smokers with a similar periodontitis, plaque and gingival bleeding experience. In addition, both smoking and osteoporosis/osteopenia provided a negative influence on alveolar bone.

Serum fatty acid imbalance in bone loss: example with periodontal disease

Among the numerous factors of bone remodelling, the local action of arachidonic acid metabolites together with cytokines, is particularly important, especially that of prostaglandin PGE2. It has been suggested that the alveolar bone destruction in periodontal disease and osteoporosis can be treated by reducing the ratio of arachidonic acid in phospholipids, which would diminish prostaglandin production. The aim of this study was to evaluate the main serum polyunsaturated fatty acids and a possible alteration in the level of arachidonic acid in patients suffering from periodontal bone loss. Of the 105 patients who participated the study, 78 were suffering from periodontal bone loss and 27 served as a control group. The fatty acids were measured in serum by gas-chromatography. The results showed that the level of fatty acids of the n-6 pathway was higher in our patients with bone loss than in the control group, whereas the reverse was observed with fatty acids of the n-3 pathway. In conclusion, our patients' bone losses are linked with an imbalance between n-6 and n-3 fatty acids, which seems to justify a diet increase in 20- and 22-carbon fatty acids.

Longitudinal alveolar bone loss in postmenopausal osteoporotic/osteopenic women

The purpose of this 2-year longitudinal clinical study was to investigate alveolar (oral) bone height and density changes in osteoporotic/osteopenic women compared with women with normal lumbar spine bone mineral density (BMD). Thirty-eight postmenopausal women completed this study; 21 women had normal BMD of the lumbar spine, while 17 women had osteoporosis or osteopenia of the lumbar spine at baseline. All subjects had a history of periodontitis and participated in 3- to 4-month periodontal maintenance programs. No subjects were current smokers. All patients were within 5 years of menopause at the start of the study. Four vertical bitewing radiographs of posterior sextants were taken at baseline and 2-year visits. Radiographs were examined using computer-assisted densitometric image analysis (CADIA) for changes in bone density at the crestal and subcrestal regions of interproximal bone. Changes in alveolar bone height were also measured. Radiographic data were analyzed by the t-test for two independent samples. Osteoporotic/osteopenic women exhibited a higher frequency of alveolar bone height loss (p<0.05) and crestal (p<0.025) and subcrestal (p<0.03) density loss relative to women with normal BMD. Estrogen deficiency was associated with increased frequency of alveolar bone crestal density loss in the osteoporotic/osteopenic women and in the overall study population (p<0.05). These data suggest that osteoporosis/osteopenia and estrogen deficiency are risk factors for alveolar bone density loss in postmenopausal women with a history of periodontitis.

Inflammatory cell population and bacterial contamination of membranes used for guided tissue regenerative procedures

The purpose of this study was to determine the types of inflammatory cells and bacterial contamination on expanded polytetrafluoroethylene (ePTFE) membranes which might affect new tissue formed by guided tissue regeneration (GTR). Forty periodontal bony defects were treated by the flap procedure, which included the use of an ePTFE membrane. Twelve months after the second surgery, the defect sites were re-evaluated for changes in probing depth and clinical attachment level. The ePTFE membranes were retrieved after 4 to 6 weeks of healing and sectioned serially at 3 microm in a coronal-apical plane. The ePTFE membrane was divided into 3 portions: cervical, middle, and apical, each of which was subdivided into outer, central, and inner segments, providing a total of 9 fields. Cells and bacteria were analyzed by light microscopy for their types: mononuclear cell, erythrocyte, fibroblast, neutrophil, plasma cell, T lymphocyte, B lymphocyte, macrophage, and oral bacteria. Both cells and bacteria decreased in number towards the apical portion and were present even in the central part. Most cells were mononuclear cells. Erythrocytes, fibroblasts, neutrophils, and plasma cells were rarely encountered. Bacteria, most of which were Gram-positive, were observed in almost the same number in the outer and inner parts. The results indicate that numerous inflammatory cells adhered to and invaded the ePTFE membranes accompanied by bacterial contamination and that there was a tendency for a negative correlation between the increment number of bacteria and the gain of clinical attachment level.

The association between estrogen status and alveolar bone density changes in postmenopausal women with a history of periodontitis

While numerous studies have demonstrated a relationship between 17-beta-estradiol (E2) deficiencies and skeletal bone loss in postmenopausal females, the influence of E2 deficiency on alveolar bone resorption is poorly understood. The purpose of this study was to examine the association between the estrogen status of postmenopausal women and alveolar bone density changes in a 1-year longitudinal study. Twenty-four postmenopausal women, within 7 years of menopause, were divided into 2 groups, E2-sufficient (n = 10) and E2-deficient (n = 14). Venous blood samples were taken at baseline, 6 months, and 1 year for radioimmunoassay determination of serum E2 levels. At baseline and 1 year, 4 vertical bite-wing radiographs were taken for computer-assisted densitometric image analysis (CADIA). Areas of interest (AOIs) for CADIA were crestal and subcrestal regions of posterior interproximal alveolar bone. Serum E2 levels were significantly higher at all 3 time points in the E2-sufficient subjects (P < 0.002), repeated measures ANOVA). Overall, mean CADIA values (0.30 +/- 0.07 for the E2-sufficient women and -0.44 +/- 0.07 for the E2-deficient women) were statistically different between groups (P < 0.001, repeated measures ANOVA), indicating that the E2-sufficient women displayed a mean net gain in alveolar bone density and the E2-deficient women displayed a mean net loss in alveolar bone density. Furthermore, the E2-sufficient women exhibited a higher frequency of sites demonstrating a gain in alveolar bone density, while the E2-deficient women exhibited a higher frequency of sites demonstrating loss in alveolar bone density. These data suggest that estrogen status may influence alveolar bone density changes as demonstrated with CADIA.

Peripheral blood leukocyte populations in the elderly with and without periodontal disease

Periodontal disease in the elderly has not been characterized. Initial reports suggest that the disease is common and severe. Deficiencies in the immune response have also been reported to occur in the elderly. Consequently it was hypothesized that aging-related changes in the immune response may contribute to the severity and occurrence of periodontal disease in the elderly. To test that hypothesis, the % and number of leukocytes and leukocyte subsets in the peripheral blood of elderly (65-75 years) subjects were tested and used as indicators of the immune potential of those individuals. Age and gender effects on several of the parameters tested were identified. With the exception of increased number of leukocytes in the elderly group with severe periodontal disease, no other alteration in the leukocyte parameters tested were identified. These results suggest that periodontal disease in the elderly was not associated with obvious changes in the leukocyte and leukocyte subsets in the peripheral blood due to aging.

Flow cytometric evaluation of phagocytosis by peripheral blood polymorphonuclear leucocytes in human periodontal diseases

The complement-dependent phagocytic functions of polymorphonuclear leucocytes (PMNL) in peripheral blood from 15 patients with localized juvenile periodontitis (LJP), 13 with generalized juvenile periodontitis (GJP) and 52 with adult periodontitis (AP), and from 30 normal subjects as controls were measured by flow cytometry. Heparinized blood was collected and incubated with fluorescent microspheres, and erythrocytes were removed. By means of single-cell analysis the percentage of phagocytosing cells (% phagocytosis) and the mean number of microspheres phagocytosed by one PMNL (degree of phagocytosis; d-phagocytosis) were measured. Some but not all patients with LJP (53%) and GJP (46%) showed consistently low % phagocytosis and d-phagocytosis. On the other hand, only 6% of AP patients and no healthy subjects showed a reduction of PMNL phagocytosis. Phagocytosis was unchanged after initial periodontal treatment in all subjects, suggesting the depression of PMNL phagocytosis may not be a transient phenomenon associated with periodontal status. Furthermore, PMNLs from the LJP patients that showed depressed phagocytic function exhibited depressed phagocytic responses with either autologous or normal plasma, while control PMNLs with either normal or the patients' plasma showed normal responses. These results suggested that the depressed phagocytic responses in LJP patients could be due to cell-associated defect(s) on the PMNL.