Association between periodontitis and acute myocardial infarction: a case-control study of a nondiabetic population.

BACKGROUND AND OBJECTIVE: Periodontitis and acute myocardial infarction (AMI) are two diseases that share common risk factors. The role of periodontitis as an independent risk factor for cardiovascular disease has been under debate. The aim of this study was to investigate whether an association exists between periodontitis and AMI in a nondiabetic population, using multiple periodontal case definitions. MATERIAL AND METHODS: Periodontal examination was performed in 204 patients with AMI. The control group comprised 102 healthy subjects, without significant coronary disease, confirmed angiographically. Periodontitis was assessed using measurements of clinical attachment loss (CAL), probing depth and number of missing teeth. From these measurements, five different case definitions of periodontitis were generated. RESULTS: Using the continuous forms of periodontal measurements, the odds ratio (95% confidence interval) of the association with incident AMI was 1.74 (1.26-2.50), 1.83 (1.10-3.17) and 1.08 (1.06-1.13) for mean CAL, probing depth and number of missing teeth, respectively. A consistent positive association was observed regardless of the case definition of periodontitis. CONCLUSION: In this nondiabetic population, the association between periodontitis and AMI was consistent across different measurements and/or definitions of periodontitis. The strength of the association increased concomitantly with the robustness of the criteria used to define periodontitis.

The effect of platelet-rich plasma (PRP) combined with a bone allograft on human periodontal ligament (PDL) cells.

The prominent purpose of the study was the evaluation of the in vitro mitogenic effect of three different homologous platelet-rich plasma (PRP) preparations (PRPa, PRPb, PRPc) on three different lines of periodontal ligament (PDL) cells (PDL(1,2,3)), cultured alone or in combination with a demineralized freeze-dried allograft (DFBA). PDL cell cultures were derived from the mid root of three maxillary caries-free premolars extracted for orthodontic reasons. Cells were grown and reached confluence. To evaluate the mitogenic effect of all exogenous factors (PRPa, PRPb, PRPc and DFBA) on PDL cells, specific number of cells (10.000/well) was cultured in the presence or absence of the above factors. Each PRP preparation (5% v/v) was added in all cell lines, in the absence or presence of 10 mg/ml of DFBA. The cells were also treated with 25 ng/ml bFGF (positive control). The mitogenic effect was evaluated 24 h after incubation, using the Trypan blue exclusion assay. The results revealed that all PRP preparations act as potent mitogens as they significantly induced cell proliferation on PDL(1,2,3) lines. All PRP preparations when added alone in the PDL cell cultures, exhibited a significant advantage over the positive control (bFGF). The addition of DFBA to PRP did not influence significantly cell proliferation in all cell lines, comparatively to PRP alone, at the time -period studied. The findings of this study demonstrate the beneficial role of PRP alone or combined with the bone graft on periodontal ligament cells in vitro, suggesting that it may be considered as a potential biological approach in periodontal regeneration.

Effect of rhTGF-ß1 combined with bone grafts on human periodontal cell differentiation.

Various techniques and materials have been proposed for the treatment of periodontal defects. In periodontal regeneration, periodontal ligament (PDL) cell differentiation as well as certain growth factors and their delivery system applied are critical. The purpose of this study was to evaluate the in vitro effect of recombinant human transforming growth factor-beta 1 (rhTGF-ß1) combined with two different bone grafts on human PDL (hPDL) cell differentiation. The hPDL cells were treated with TGF-ß1 alone or in combination with a calcified freeze-dried bone allograft (FDBA) and a porous biphasic calcium phosphate (BC) bone graft. Cell differentiation effect was estimated by measuring alkaline phosphatase (ALPase) activity and osteocalcin secretion. Results demonstrated that rhTGF-ß1 alone or in combination with FDBA and BC provoked a significant (p<0.05) increase in ALPase activity as compared with controls. The findings of this study confirmed the beneficial role of rhTGF-ß1 combined with FDBA and BC as carriers in periodontal regeneration.

Effect of homologous PRP on proliferation of human periodontally affected osteoblasts. In vitro preliminary study. Report of a case.

OBJECTIVE: The purpose of this in vitro study was to evaluate the effect of two concentrations of homologous platelet-rich plasma (PRP) on the proliferative response of osteoblasts derived from a patient with aggressive periodontitis. METHODS: 8.5 ml of venous blood were taken from 1 healthy and non-smoker volunteer. PRP was prepared following the protocol of Curasan. Osteoblasts were derived from alveolar bone chips obtained from a patient with aggressive periodontitis during conventional periodontal surgery and a clinically healthy person during crown lengthening surgical procedure. Cells were grown in 24-well dishes and on day 2 of quiescence were treated with 1% and 5% (v/v) of PRP. The effect on cell proliferation was estimated by measuring [3H] thymidine incorporation. After 48h of incubation, cells were processed to subject to scintillation counting. Counts per minute were determined for each sample. RESULTS: The addition of 1% and 5% of PRP provoked a statistical significant (p<0.05) increase in cell growth. CONCLUSIONS: Data revealed significant enhancement of proliferative response of osteoblasts in the presence of PRP, which might serve as a source of growth factors promoting periodontal repair by modulating cell response and activities.

Effect of rhBMP-7 combined with two bone grafts on human periodontal ligament cell differentiation.

The purpose of this study was to evaluate the in vitro effect of recombinant human bone morphogenetic protein-7 (rhBMP-7) combined with demineralised freeze-dried bone allograft (DFDBA) and an inorganic bovine material with a synthetic peptide (PepGen P-15) on human periodontal ligament (hPDL) cell differentiation, in a time-dependent manner. hPDL cells were cultured and treated with: (1) 500 ng/ml of rhBMP-7, (2) 10 mg of DFDBA or PepGen P-15 and (3) their combination. Cell differentiation was estimated after 48 and 72 h by measuring alkaline phosphatase (ALPase) activity and osteocalcin (OC) secretion. The presence of rhBMP-7, DFDBA, PepGen P-15, rhBMP-7 + DFDBA and rhBMP-7+ PepGen P-15 promoted a significant increase of ALPase activity after 48 and 72 h. The combination of rhBMP-7 with DFDBA or PepGen P-15 did not lead to significant OC secretion. The results of this study imply that rhBMP-7 stimulates the early osteoblastic differentiation of hPDL cells and that DFDBA and PepGen P-15 could serve as carriers for rhBMP-7.

Contamination of a toothbrush with antibacterial properties by oral microorganisms.

OBJECTIVES: The aim of this study was to examine the contamination and the survival rate of periodontopathic and cariogenic species on new toothbrushes with antibacterial properties (coated bristles with triclosan), after a single use in periodontitis patients. The decontamination effect of the use of toothpaste was also evaluated. METHODS: Ten patients, who consulted the Department of Periodontology, for treatment of chronic periodontitis, were selected. In each patient four different toothbrushes were used. Two quadrants, randomly selected, were each brushed using a different antibacterial toothbrush. In one of these two quadrants toothpaste was used. The same happened with the remaining quadrants, only with regular toothbrushes. After brushing, the toothbrushes were rinsed and stored in room temperature and a dry environment. After 0, 4 and 24h, four tufts, from each toothbrush, were cut and processed for selective and non-selective culturing techniques, followed by identification and quantification of all species found. RESULTS: Immediately after brushing the toothbrushes harbored a significant number of microorganisms, with no statistically significant difference between the two types of brushes (regular and antibacterial). The reduction of microorganisms from 0 to 4h after brushing was statistically significant (p<0.05). The difference was less obvious from 4 to 24h. When toothpaste was used, brushes harbored significantly (p<0.05) lower numbers of colony-forming units (CFU) compared to those without the use of toothpaste. CONCLUSIONS: The antibacterial toothbrush with triclosan coated tufts failed to limit the bacterial contamination. The toothpaste, on the other hand, significantly reduced the contamination of toothbrushes.

Role of growth factors on periodontal repair.

Regeneration of periodontal structures lost during periodontal diseases constitutes a complex biological process regulated among others by interactions between cells and growth factors. Growth factors are biologically active polypeptides affecting the proliferation, chemotaxis and differentiation of cells from epithelium, bone and connective tissue. They express their action by binding to specific cell-surface receptors present on various target cells including osteoblasts, cementoblasts and periodontal ligament fibroblasts. The observation that growth factors participate in all cell functions led to exogenous application during periodontal tissue repair aiming to their use as an alternative therapeutic approach to periodontal therapy. Cell types and cultures conditions, dose, carrier materials, application requirements are of critical importance in the outcome of periodontal repair. The purpose of this article is to review the literature with respect to the biological actions of PDGF, TGF, FGF, IGF and EGF on periodontal cells and tissues, which are involved in periodontal regeneration.

Human periodontal ligament cell responses to recombinant human bone morphogenetic protein-2 with and without bone allografts.

BACKGROUND: Recombinant human bone morphogenetic protein-2 (rhBMP-2) has been found to promote the osteoblastic differentiation of human periodontal ligament cells. Its effect depends on the delivery system used. In this study we examined the effect of rhBMP-2 on the proliferation and osteoblastic differentiation of human periodontal ligament cells cultured alone or with 3 different bone allografts. METHODS: The rhBMP-2 effect on cell proliferation and osteoblastic differentiation was examined by measuring [3H] thymidine incorporation and ALPase activity, respectively, on human periodontal ligament (hPDL) cells. Two human demineralized freeze-dried allografts of cortical (DFDBAco) and cancellous (DFBDAca) bone origin and 1 non-demineralized freeze-dried allograft (FDBA) of cancellous bone origin, derived from different tissue banks, were used to evaluate the rhBMP-2 effect on cell osteoblastic differentiation. The measurements were taken on various days. RESULTS: rhBMP-2 decreased hPDL cell proliferation. rhBMP-2 acted on the third day of the process of cell differentiation, had a specific time of action, achieved its peak effect on the fourth and fifth days, and then did not provoke any further effects. The 3 bone allografts were efficiently combined with rhBMP-2. The combination of rhBMP-2 and DFDBAco showed the effect with the longest duration. rhBMP-2, on day 4, made the inactive bone allograft more active while, on the other days, its effect was dependent on the allograft alone. CONCLUSIONS: rhBMP-2 promotes the osteoblastic differentiation of human periodontal ligament cells and decreases cell proliferation. In this study rhBMP-2 in the presence of the bone allografts tested resulted in hPDL cell differentiation.

Proliferative effect of growth factors TGF-beta1, PDGF-BB and rhBMP-2 on human gingival fibroblasts and periodontal ligament cells.

The regeneration of periodontal tissues lost due to periodontal disease requires cell migration, differentiation and proliferation. Several procedures have been proposed to promote wound healing events such as the application of growth factors including PDGF-BB, TGF-beta1 and rhBMP-2. The purpose of this study was to evaluate the mitogenic responses of human periodontal ligament cells and gingival fibroblasts to PDGF-BB, TGF-beta1 and rhBMP-2. Human periodontal ligament cells were isolated from the mid root of three maxillary third molars extracted from three adult patients with moderate periodontitis and gingival fibroblasts were obtained from two patients also affected by moderate periodontitis, who underwent periodontal surgery. Cells were grown in 24-well dishes. On day 2 of quiescence, new medium was added with PDGF-BB or TGF-beta1 or rhBMP-2 at the concentration of 10 ng/ml. To determine the effects of the test agents on cell proliferation, DNA synthesis was estimated by measuring [3H] thymidine incorporation. After 48h of incubation the cells were processed and subject to scintillation counting. Counts per minute (cpm/ well) were determined for each sample. The results of this study demonstrated that PDGF-BB acts like a strong mitogenic agent for human periodontal ligament cells and gingival fibroblasts, TGF-beta1 mostly supports the proliferation of these cells and rhBMP-2 had an opposite effect on cell mitosis.

In vitro evaluation of the mitogenic effect of platelet-derived growth factor-BB on human periodontal ligament cells cultured with various bone allografts.

BACKGROUND: Several studies have documented the role of growth factors in periodontal regeneration. It has been shown that platelet-derived growth factor (PDGF) is a potent stimulator of human periodontal ligament (PDL) cells. A variety of bone graft materials are used to treat osseous defects caused by periodontal disease. We evaluated the mitogenic effect of PDGF on human PDL cells cultured with different allografts to determine which of the allografts with or without PDGF promoted periodontal regeneration. METHODS: Two human demineralized freeze-dried allografts of cortical (DFDBA) and cancellous (DFBA) bone and a non-demineralized freeze-dried allograft (FBA) from cancellous bone were used alone or supplemented with PDGF-BB. Human PDL cultures were derived from the mid-root of 2 maxillary premolars extracted for orthodontic reasons. Cells were grown separately in 24-well dishes with or without 20 mg of each bone allograft. On day 2 of quiescence, new medium was added with 10 ng/ml of PDGF-BB. DNA synthesis was estimated by measuring [3H] thymidine incorporation to determine the effects of the test agents on cell proliferation. Cells were processed and subjected to scintillation counting after 48 hours of incubation. Counts per minute (cpm/well) were determined for each sample. RESULTS: There was no statistically significant difference (P<0.05) on PDL cell proliferation when the allografts were used alone. PDL cells exhibited significantly greater proliferative responses to the 2 demineralized bone allografts, DFDBA and DFBA, when combined with PDGF-BB. A statistically significant difference on DNA synthesis was noticed when PDGF-BB was added to PDL cells cultured with FBA. PDL cells displayed no significant increase in mitogenic activity when cultured with PDGF-BB alone. CONCLUSIONS: The findings of this study demonstrate the beneficial role of DFDBA, DFBA, and FBA as synergic agents with PDGF-BB to periodontal regeneration. The significant ability of the 2 decalcified bone allografts, DFDBA and DFBA, combined with PDGF to stimulate PDL cell proliferation might be a useful adjunct in the treatment of periodontal defects.

Ability of a bovine bone graft, alone or enriched with PDGF-BB or rhBMP-2, to promote human periodontal ligament (PDL) cells proliferation. A preliminary study.

One of the most important goals of the periodontal therapy procedures is to stimulate the formation of new bone into osseous defects resulted from periodontal disease. A wide range of grafting materials is used to achieve this aim. Recently, the Human Tissue Bank of the National Center for Scientific Research 'Demokritos' in Athens (Greece) has prepared, in a preliminary study, a cancellous bovine-derived bone matrix (BBM). The purpose of the present work was to investigate the role of this bovine bone material in the periodontal regeneration, by studying the rate of human periodontal ligament (PDL) cells proliferation in the presence of this matrix alone, or after the addition of the growth factors, platelet-derived growth factor-BB (PDGF-BB) or recombinant human bone morphogenetic protein-2 (rhBMP-2).Bovine bone graft was prepared using the 'know how' acquired by the 30 years continuous preparation and delivery of lyophilized human bone grafts by the 'Demokritos' Bank.PDL cells cultures were derived from the mid root of two maxillary premolars. The teeth were caries-free and were extracted for orthodontic reasons from 1 adult female patient. Cells were grown in 24-well dishes in the presence of 20 mg BBM. On day 2 of quiescence, new medium was added with 10 ng/ml of PDGF-BB or 50 ng/ml of rhBMP-2. To determine the effects of the test agents on cell proliferation, DNA synthesis was estimated by measuring [(3)H] thymidine incorporation. After 48 h of incubation the cells were processed to subject to scintillation counting. Counts per minute (cpm/well) were determined for each sample.The results revealed that this BBM has the ability to maintain PDL cells proliferation and could be used as an alternative graft material. PDGF-BB when added improved the cell proliferative response resulting in a more active BBM, while the presence of rhBMP-2 did not support cell mitosis.

[Pain. Evaluation of the developing pain theories. The psychological factor]. / O ponos. Axiologese ton theorion demiourgias tou ponou o psychologikos paragontas.

In this paper we presented the different theories and opinions regarding the development of pain. After a very brief historical review including the ideas of Homer, Hippocrates, Aristoteles, St. Thomas Aquinas, we reviewed the 19th century's theories including Whytt, Brodie, Inman and Austie. From the modern period we emphasized the "gate theory" introduced originally by Melzack and Well. The psychological aspects has been also examined and the patient as "a dental patient" also described.