Effect of Full-mouth Disinfection Protocol on Glycaemic Control and Subgingival Microbiota in Patients with Type 1 and Type 2 Diabetes.

PURPOSE: To evaluate the effect of a full-mouth disinfection protocol (FMD) on periodontal parameters, glycaemic control and subgingival microbiota of periodontal patients with type 1 and type 2 diabetes, as well as those without diabetes. MATERIALS AND METHODS: This study included 33 patients with periodontitis. Eleven of them were type 1 diabetes patients, 11 were type 2 diabetes patients, and 11 were non-diabetics. At baseline and 3 months after the FMD, the periodontal parameters of each patient were recorded, samples of capillary blood for the chairside assessment of HbA1c were taken, and plaque samples from the two deepest periodontal pockets were collected to test for the presence of Aggregatibacter actinomycetemcomitans (Aa), Porphyromonas gingivalis (Pg), Prevotella intermedia (Pi), Tannerella forsythia (Tf) and Treponema denticola (Td). RESULTS: Bleeding on probing (BOP), probing pocket depth (PPD), clinical attachment level (CAL) and glycated haemoglobin (HbA1c) decreased statistically significantly (p < 0.05) in all three groups 3 months after FMD. Only the proportion of Pg in the control group decreased statistically significantly (p < 0.05), while the proportion of other bacteria decreased or remained the same, whereby the differences were not statistically significant. Moreover, the proportion of Aa in type 1 diabetics increased statistically significantly (p < 0.05). CONCLUSION: The FMD protocol improves periodontal parameters and glycaemic control of type 1 and type 2 diabetes patients with periodontitis.

A Longitudinal Study of DMFT Counts in a Population of Ljubljana Over a Thirty Year Period.

PURPOSE: Few longitudinal studies on changes of decayed, missing, or filled teeth (DMFT) counts in a population have been reported. This study aimed to evaluate the changes in DMFT counts in Ljubljana citizens in a 30-year period. MATERIALS AND METHODS: 238 dentate subjects that attended the third epidemiological study were invited. Ninety 45-95-year-old subjects (37.8%) responded to our invitation. Two (2.2%) edentulous subjects were excluded. Among the dentate subjects there were 28 men and 60 women. They were divided in six age groups with mean age of 45, 55, 65, 75, 85, and 95 years. The number of subjects in each age group was: 29, 12, 21, 18, 7, and 1, respectively. For evaluation of the state of teeth we used the DMFT index. RESULTS: The average DMFT value for 45-95-year-old population was 19.3. Mean DMFT counts in all comparable age groups (45-, 55- and 65-years) decreased in 30 years. In 45 year olds they decreased from 17.5 to 15.7, in 55-year-olds they decreased from 20.4 to 19.2, and in 65 year olds they decreased from 22.5 to 20.7. An increase of the average number of present teeth (for 6.4 teeth in average) from the first to the fourth study in subjects of the same age was seen. CONCLUSION: Dental health in Slovenia has improved in 30 years. Average DMFT counts in subjects of the same age (45-, 55- and 65-years) have decreased. Ljubljana citizens have less decayed, less missing and more filled teeth than 30 years ago.

A Longitudinal Study of Periodontal Treatment Needs in a Ljubljana Population over a 30-year Period.

PURPOSE: Only a few studies have presented long-term trends in the prevalence of periodontitis and periodontal treatment needs. The aim of this study was to report the changes in periodontal treatment needs of an adult population in Ljubljana, Slovenia, over a 30-year period. MATERIALS AND METHODS: This study included 88 45- to 95-year-old subjects who had attended the previous three studies 10, 20 and 30 years ago. We used the CPITN for assessing periodontal treatment needs, as the same index had been used in the previous three studies. RESULTS: None of the examined subjects had healthy periodontal tissues, all needed oral hygiene instruction, 96.6% needed scaling and root planing as well as oral hygiene instruction, 47.7% needed complex periodontal treatment as well as oral hygiene instruction plus scaling and root planing. Periodontal treatment needs in Ljubljana adults increased in thirty years in the total study population as well as among 45- to 65-year-olds. CONCLUSION: Periodontal treatment needs in an adult population of Ljubljana are high and have increased in the last thirty years. More effective primary and secondary preventive measures are needed to decrease the prevalence of periodontal disease and periodontal treatment needs in the adult population of Ljubljana, Slovenia.

Toll-like receptor 4 expression in trigeminal neurons is increased during ligature-induced periodontitis in rats.

BACKGROUND: Periodontitis, activated by oral bacteria and orchestrated by innate immune response, is regulated by primary nociceptive neurons, which are generally considered to have small- to medium-sized perikaryons. Bacterial byproducts (e.g., lipopolysaccharides) activate primary nociceptive neurons directly through Toll-like receptors (TLRs). Therefore, this study aims to morphometrically characterize rat trigeminal neurons, which express TLR4, and to investigate the changes in the TLR4 expression in neurons during periodontal inflammation. METHODS: Trigeminal neurons innervating gingivomucosa were identified by application of the retrograde tracer hydroxystilbamidine into the gingival sulcus of the maxillary molar in 14 rats. Periodontitis was induced by ligature around the same molar in seven rats. TLR4 expression was investigated by immunohistochemistry on paraffin sections of the trigeminal ganglia (TG). Semiquantitative method was used to identify the intensity of TLR4 expression. RESULTS: In the control group without the ligatures, TLR4 was detected in 19% of the neurons in the maxillary region of TG and in 29% of neurons innervating gingivomucosa. Expression of TLR4 was more frequent and intensive in small- to medium-sized neurons than in large-sized neurons. One week after ligature-induced periodontitis, the percentage of TLR4-positive neurons in the maxillary region and among the neurons innervating inflamed gingivomucosa significantly increased statistically to 32% and 41%, respectively. CONCLUSIONS: TLR4 is predominantly, but not exclusively, expressed in smaller trigeminal nociceptive neurons in the rat. Experimental periodontitis upregulates TLR4 expression in the trigeminal neurons. The hypothesis that bacterial byproducts regulate the pathogenesis of periodontitis by activation of trigeminal nociceptors through TLR4 should be explored.

Dental pulp and gingivomucosa in rats are innervated by two morphologically and neurochemically different populations of nociceptors.

OBJECTIVES: Difference in phenotypes of sensory neurons innervating dental pulp or gingivomucosa may be responsible for intense pain sensations in pulpitis in contrast to relatively painless chronic periodontitis. Therefore, we classified these neurons according to their size and two neurochemical characteristics of nociceptors, their TrkA expression and isolectin IB4 binding. DESIGN: In rats (n=6) fluorescent tracers Fluorogold and TrueBlue were simultaneously applied into the standard-sized tooth cavity and nearby gingival sulcus, respectively. After the fluorescence on paraffin trigeminal ganglia (TG) sections was identified and photographed, immunohistochemistry for TrkA expression and IB4 binding was performed on the same sections. RESULTS: The average sizes of TG neurons projecting to the gingivomucosa and dental pulp were 894±441µm(2) and 1012±381µm(2), respectively. The proportions of small-sized gingival and pulpal neurons were 14% and 5%, respectively (p<0.05). The proportions of TrkA-positive neurons among all gingival or pulpal neurons were 76% and 86%, respectively (p<0.05). Among all gingival or pulpal neurons the proportions of IB4-positive neurons were 46% and 3% (p<0.001), respectively, and the majority of them were small-medium sized. CONCLUSIONS: Dental pulp and gingivomucosa are richly innervated by nociceptive TrkA-expressing neurons. However, while great majority of pulpal neurons are larger NGF-dependent A-fibre nociceptors without affinity to bind IB4, almost half of the gingival neurons are smaller IB4 binding C-fibre nociceptors. The difference in phenotype of sensory neurons might partially explain the different sensitivity of both tissues during normal and pathological conditions.

Prevalence of periodontal pathogens and metabolic control of type 1 diabetes patients.

OBJECTIVE: The aim of the study was to evaluate the prevalence of periodontal pathogens Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Prevotella intermedia, Tannerella forsythia and Treponema denticola in subgingival plaque collected at different probing depths of type 1 diabetes patients with periodontal disease in correlation to metabolic control. METHODS: Twenty-one patients 40 to 50 years old were included in the study. In each patient blood samples were taken for the evaluation of HbA1c level and subgingival plaque samples were taken with paper points from the two deepest pockets. The presence of five periodontal pathogens was detected by multiplex polymerase chain reaction. RESULTS: The results of 38 plaque samples showed that T. forsythia was found in 48% followed by T. denticola in 31%, P. gingivalis in 26%, P. intermedia in 9% and A. actinomycetemcomitans in 7%. T. forsythia and T. denticola were the most frequent combination of periodontal pathogens found in the same sample. The serum level of HbA1c in nine patients where T. forsythia was detected (7.5 +/- 1.4%) was significantly higher (F-test, p = 0.001) than in 12 patients where T. forsythia was not detected (6.8 +/- 0.5%). Similarly, the serum level of HbA1c was significantly higher (F-test, p = 0.001) in eight patients where T. denticola was detected (7.5 +/- 1.8%) compared to the 13 patients where T. denticola was not detected (7.0 +/- 0.5%). No such correlation was found for P. gingivalis, P. intermedia or A. actinomycetemcomitans. CONCLUSIONS: We conclude that T. forsythia and T. denticola are most frequently found in subgingival plaque samples of type 1 diabetic patients and these findings correlate with poorer metabolic control of diabetes.

Periodontal inflammatory burden correlates with C-reactive protein serum level.

OBJECTIVE: The aim of study was to present a new method for evaluation of the periodontal inflammatory burden, to apply the method to the adult population and to correlate it with serum levels of C-reactive protein (CRP). MATERIALS AND METHODS: On 515 extracted teeth was measured the neck circumferences (NC). The average values of the NC were obtained for 16 male and 16 female individual tooth types. In the clinical part of this study 238 dentate subjects were included. The subgingival area, inflamed area and periodontal wound size were calculated from NC, probing depth and BOP. The sum of the inflamed and ulcerated subgingival areas of all teeth represented the total periodontal inflammatory burden of an individual. Serum levels of CRP were measured by immunochemical method. RESULTS: The average subgingival area in 238 subjects was calculated to be 13.11 ± 6.35 cm(2) and inflammatory burden area 9.25 ± 5.57 cm(2). The periodontal bleeding wound (p < 0.05) was significantly larger in men. The increased serum levels of CRP correlated with periodontal inflammatory burden (p < 0.05). CONCLUSIONS: This new method quantifies the inflammatory burden caused by periodontal disease. The size of the inflammatory burden is correlated with increased serum levels of CRP.

Systemic use of selective iNOS inhibitor 1400W or non-selective NOS inhibitor l-NAME differently affects systemic nitric oxide formation after oral Porphyromonas gingivalis inoculation in mice.

OBJECTIVE: Nitric oxide synthase (NOS) inhibitors are reported to protect against the local tissue damage in gingivitis and periodontal disease by reducing nitroxidative stress during inflammation, but their systemic effects are not well investigated. DESIGN: NOS inhibitors systemic effects were investigated in a murine chronic oral inoculation model using live Porphyromonas gingivalis ATCC 33277 (0.3 ml; 10(9)cfu/ml) or sterile broth (0.3 ml). Organ nitric oxide (NO) and plasma nitrite/nitrate (NOx) were determined in mice treated with non-selective NOS inhibitor l-NAME (50mg/kg/24h i.p.) or selective iNOS inhibitor 1400W (10mg/kg/6h i.p.) for the last 5 days of the experiment. Differences between groups were evaluated by nonparametric Wilcoxon's rank-sum one-sided two-sample test and the results compared to those obtained from sham-treated (sterile broth) sham-inoculated animals (water for injection i.p./6h). RESULTS: Repeated ingestion of P. gingivalis resulted in generalized production of NO in organs and NOx in plasma, the levels of both typically being reduced in P. gingivalis-inoculated-1400W-treated mice, whilst the use of l-NAME was largerly ineffective, even promoting NO/NOx formation. Application of either inhibitor to sham-inoculated animals enhanced NO/NOx formation, due only in part to the repeated i.p. injections. CONCLUSIONS: The systemic use of 1400W or l-NAME differently affects systemic nitric oxide formation in mice orally challenged with P. gingivalis, but the sequelae of such an intervention should be evaluated further.

Periodontal disease burden and pathological changes in organs of dogs.

Bacterial plaque associated periodontal disease is the most common chronic infection in man and dogs. In man, there is an association between periodontal disease and myocardial infarction and stroke, while in dogs it has also been associated with changes in internal organs. Inflamed periodontal tissues present a 'periodontal disease burden' to the host and the extent of this inflammatory disease burden is likely to affect the degree of associated pathological change in distant organs. This hypothesis was investigated in dogs with naturally occurring periodontal disease. Post-mortem investigations including periodontal assessment, standard necropsy, and organ histology were performed on 44 mature toy and miniature Poodles (related, periodontitis predisposed breeds) that died naturally or were euthanized based on clinical disease. Animals with gross primary organ pathology were excluded. The periodontal disease burden was estimated from the total surface area of periodontal pocket epithelium using six measurements of probing depth for each tooth and the tooth circumferences. Ordinal logistic regression (OR) analysis established that for each square centimeter of periodontal disease burden there was a 1.4-times higher likelihood of greater changes being present in the left atrio-ventricular valves (OR = 1.43), plus 1.2 and 1.4 times higher likelihoodfor greater liver and kidney pathology (OR = 1.21; OR = 1.42), respectively The results show that there is a link between the estimated 'periodontal disease burden' resulting from plaque-bacteria associated periodontal disease and the level of internal pathology in this population, implying that periodontitis might contribute to the development of systemic pathology in dogs.

Unilateral ligature-induced periodontitis influences the expression of neuropeptides in the ipsilateral and contralateral trigeminal ganglion in rats.

OBJECTIVES: Expression of neuronal neuropeptides in inflammatory conditions is altered. The changes in expression of substance P (SP) and calcitonin gene-related peptide (CGRP) in ipsilateral and contralateral trigeminal ganglion (TG) neurons were investigated by immunohistochemistry one week after unilateral ligature-induced periodontitis in rats. DESIGN: A retrograde nerve tracer Fluorogold (FG) was applied into the gingival sulcus of the second maxillary molar to identify the neurons in TG that specifically innervate the inflamed gingivomucosa. In addition, neurons from the corresponding maxillary and the adjacent mandibular-ophthalmic regions in TG were analysed. RESULTS: Statistically significantly higher frequencies of CGRP-positive neurons, regardless of their size, were found in TG ipsilateral to the periodontitis (83% and 73% in FG-labelled and maxillary regions, respectively) than in the control group without periodontitis (52% and 42% in FG-labelled and maxillary regions, respectively). The frequency of small FG-labelled SP-positive neurons in the ipsilateral TG (60%) was significantly higher than in the control TG (25%). In the contralateral TG the frequency of CGRP-positive neurons in maxillary region (66%) was significantly higher than in the control group. Surprisingly, the number of SP-positive neurons in all regions of contralateral TG decreased when compared to control and ipsilateral TGs. CONCLUSIONS: Taken together, these results implicate a role of neurogenic component in the pathogenesis of periodontitis. The contralateral response in the TG could be mediated through the transmedian neurological pathways crossing in the trigeminal nuclear complex or through the systemic inflammatory reaction and the activation of the so called "neuro-immune axis".

Clinical evaluation of periodontal surgical treatment with an Er:YAG laser: 5-year results.

BACKGROUND: The aim of the present study was to evaluate and compare the long-term clinical outcomes of erbium-doped:yttrium, aluminum, and garnet (Er:YAG) laser-assisted periodontal flap surgery versus conventional treatment with the modified Widman flap procedure. METHODS: A total of 146 single-rooted periodontally involved teeth from 25 patients were included in this study. In each patient, left or right maxillary single-rooted teeth were assigned randomly to one of two groups: group A (Er:YAG laser) and group B (modified Widman flap surgery). Er:YAG laser was used to debride the bone pockets, scale the root surface, and trim the periodontal flap. Recession, probing depth (PD), clinical attachment level (CAL), plaque index (PI), gingival index (GI), and bleeding on probing (BOP) scores were recorded at baseline and at 3, 6, 12, 24, 36, 48, and 60 months. RESULTS: Both treatments resulted in decreases in PD, PI, GI, and BOP, increases in gingival recession, and gains in CAL. PD reduction in group A versus group B was statistically significant at 6, 12, 24, and 36 months (P < 0.05). Gains in CAL were significantly greater in group A versus group B at 6, 12, 24, and 36 months. BOP scores were significantly lower in group A versus group B at 3 and 6 months (P < 0.05). All other differences between treatment groups were not statistically significant. CONCLUSIONS: Surgical treatment of single-rooted teeth with chronic periodontitis using the Er:YAG laser yields greater PD reduction and gains in CAL for up to 3 years compared to conventional Widman flap surgery. The short-term results obtained with both treatments can be maintained over 5 years.

Expression of TrkA receptor for neurotrophins in trigeminal neurons innervating the rat gingivomucosal tissue.

The purpose of this study was to characterize and evaluate the expression of TrkA receptor in trigeminal ganglion (TG) neurons that innervate the rat gingivomucosal tissue. A retrograde nerve tracer Fluorogold (FG) was injected into the gingiva (group 1) or applied into the gingival sulcus (group 2) of the first right maxillary molar to identify the neurons in TG that innervate the gingivomucosa. After 10 days TG were dissected and FG fluorescence in neurons was observed under UV light microscope. To draw a comparison, approximately 1000 neurons per ganglion from the entire TG (group 3) and approximately 350 neurons per ganglion from the maxillary region in TG (group 4), were analyzed. Expression of TrkA receptor in TG neurons was investigated by immunohistochemistry. About 70% of neurons in groups 1 and 2 contained TrkA receptor, which was statistically significantly more than in groups 3 (41%) and 4 (38%). FG-labeled TrkA-immunopositive neurons were predominantly small or medium-sized (less than 1200microm(2)). However, the neurons innervating the rat gingivomucosa were on average larger than the neurons in the entire TG or in the maxillary region. In conclusion, the majority of neurons in TG that innervate the rat gingivomucosa are small or medium-sized, contain TrkA receptor and are most probably nociceptive.

Proinflammatory and antimicrobial nitric oxide in gingival fluid of diabetic patients with periodontal disease.

Abnormal nitric oxide (NO) synthesis has been implicated in the pathogenesis of both periodontal disease and diabetes mellitus. In diabetic patients, increased inducible NO synthase in inflamed gingiva correlated with NO in gingival crevicular fluid. Although increased NO reflected more-severe inflammation, it was associated with reductions in CFU of Prevotella intermedia, a major periodontopathogen, highlighting dual roles for NO.

The impact of image information on compressibility and degradation in medical image compression.

The aim of the study was to demonstrate and critically discuss the influence of image information on compressibility and image degradation. The influence of image information on image compression was demonstrated on the axial computed tomography images of a head. The standard Joint Photographic Expert Group (JPEG) and JPEG 2000 compression methods were used in compression ratio (CR) and in quality factor (QF) compression modes. Image information was estimated by calculating image entropy, while the effects of image compression were evaluated quantitatively, by file size reduction and by local and global mean square error (MSE), and qualitatively, by visual perception of distortion in high and low contrast test patterns. In QF compression mode, a strong correlation between image entropy and file size was found for JPEG (r=0.87, p < 0.001) and JPEG 2000 (r=0.84, p < 0.001), while corresponding local MSE was constant (4.54) or nearly constant (2.36-2.37), respectively. For JPEG 2000 CR compression mode, CR was nearly constant (1:25), while local MSE varied considerably (2.26 and 10.09). The obtained qualitative and quantitative results clearly demonstrate that image degradation highly depends on image information, which indicates that the degree of image degradation cannot be guaranteed in CR but only in QF compression mode. CR is therefore not a measure of choice for expressing the degree of image degradation in medical image compression. Moreover, even when using QF compression modes, objective evaluation, and comparison of the compression methods within and between studies is often not possible due to the lack of standardization of compression quality scales.

Identification and neuropeptide content of trigeminal neurons innervating the rat gingivomucosal tissue.

OBJECTIVES: The purpose of this study was to identify and characterise the neuropeptide content and the size of trigeminal ganglion (TG) neurons innervating the rat gingivomucosal tissue. DESIGN: Retrograde nerve tracer Fluorogold (FG) was injected into the gingiva (group 1, n=5) or applied into the gingival sulcus (group 2, n=5) of the first right maxillary molar. After 10 days, the ganglia were dissected and FG fluorescence was observed under UV light microscope. Expression of calcitonin gene-related peptide (CGRP) and substance P (SP) in FG-labelled neurons was investigated by immunohistochemistry. Cross-sectional areas of neuron cell bodies containing FG were determined. As a control group, approximately 1000 neuron cell bodies representing the entire TG neuron population was evaluated in five trigeminal ganglia. RESULTS: In group 1, the percentages of neurons containing CGRP (median 63%, range 48-72%) and SP (median 64%, range 54-64%) were significantly greater than in the control group (CGRP: median 43%, range 42-47% and SP: median 23%, range 21-27%). In group 2, only the percentage of neurons containing SP (median 50%, range 40-56%) was significantly greater than in the control group. FG-labelled neurons were predominantly small or medium sized (less than 1200 microm2). The neurons in the group 1 were significantly smaller than in group 2. In both experimental groups, immunopositive neurons were significantly smaller than immunonegative neurons. CONCLUSIONS: The majority of neurons in TG that innervate the rat gingivomucosa are small or medium sized and contain CGRP and SP.

Periodontal disease and diabetes metabolic control: a full-mouth disinfection approach.

Some studies demonstrated that local mechanical periodontal treatment and systemic antibiotics might improve the level of metabolic control in patients with diabetes. The aim of this clinical pilot trial was to evaluate if type 1 diabetes patients with periodontitis will experience improvement in periodontal status and glycemic control after a full-mouth disinfection treatment. Ten adult patients with poor metabolic control (mean glycated hemoglobin (HbA1c) = 10.7 %) and periodontitis were included in the study. All patients received a full-mouth disinfection in 24 hours as described by Quirynen et al. (1995) at baseline and 6 months later. The periodontal parameters included plaque index (PI), bleeding on probing, probing depth and clinical attachment loss. Metabolic control was measured by the serum level of HbA1c. All measurements were done at baseline and at 3, 6, 9 and 12 months. The results demonstrated a significantly lower PI, less bleeding on probing, reduction in probing depth and gain of clinical attachment at 3 months and 9 months of the study. Similarly, a significant reduction in the serum level of HbA1c was measured three months after full-mouth disinfection but disappeared 6 months later at the 6- and 12-month check points. We conclude that a full-mouth disinfection approach significantly improves periodontal status and metabolic control in type 1 diabetes patients with periodontitis. However, the results of our study imply that a full-mouth disinfection method has to be applied at least every 3 months to control periodontal status and glycemic control in type 1 diabetes patients. Further studies with greater numbers of diabetes patients are needed to confirm the long-term beneficial effects of a full-mouth disinfection approach on diabetic metabolic control.

Periodontal treatment by Arestin and its effects on glycemic control in type 1 diabetes patients.

Studies indicate that a dual pathway between diabetes mellitus and periodontal disease exists. Elimination of periodontal infection by using systemic antibiotics in conjunction with scaling and root planing (SRP) improved metabolic control in diabetic patients, as defined by reduction in glycated haemoglobin or reduction in insulin requirements (Grossi and Genco, 1998). The aim of this randomised pilot clinical trial was to determine if type 1 diabetes patients with periodontitis will experience a reduction in HbA1c levels when treated with locally delivered minocycline microspheres (Arestin) as an adjunct to scaling and root planing. Twenty adult patients with poorly controlled diabetes (HbA1c 7.5%) and adult periodontitis, as determined by the presence of four teeth with 5 mm periodontal pockets, two of which had 6-9 mm pockets and bleeding on probing, were included in the study. All patients received full mouth SRP at baseline. Arestin was administered to all pockets > or => or = 5 mm at baseline and again at 12 weeks in the test group. Probing depth (PD), clinical attachment level (CAL), plaque index (PI), gingival index (GI), and HbA1c were evaluated at baseline and at weeks 6, 12, 18 and 24. The results demonstrated that local administration of Arestin as an adjunct to scaling and root planing is significantly more effective in reducing probing depths and providing a gain in clinical attachment levels than scaling and root planing alone in type 1 diabetic patients. Hb1Ac was reduced in all patients; however the difference between the test and control groups was not significant.

Measurement of total antioxidant capacity in gingival crevicular fluid and serum in dogs with periodontal disease.

OBJECTIVE: To determine whether gingival crevicular fluid (GCF) and serum total antioxidant capacities (TACs) correlate with the degree of severity of periodontal disease in dogs. ANIMALS: 41 Toy and Miniature Poodles. PROCEDURES: After assessment of the degree of severity of naturally occurring periodontitis, GCF samples from both maxillary fourth premolars and a blood sample were collected from each dog. The condition of the periodontium of the entire dentition and at each site of GCF collection was recorded. Clinical parameters assessed included plaque index, gingival index, and probing depth. Radiographic analysis of alveolar bone level was also performed. Total antioxidant capacity was measured in GCF and serum samples by use of a commercial kit. RESULTS: Dogs with gingivitis and minimal periodontitis had significantly higher TAC in GCF than dogs with advanced periodontitis. Bivariate regression analysis revealed significant negative correlations between TAC in GCF and clinical parameters and age. The TAC in serum was significantly negatively correlated with the degree of gingival inflammation but was not significantly correlated with age. CONCLUSIONS AND CLINICAL RELEVANCE: TAC in GCF is related to the degree of severity of periodontal disease in dogs. This is likely the result of release of reactive oxygen species by activated phagocytes and fibroblasts in the inflamed periodontal tissues. The results of our study suggest that the local delivery of antioxidants may be a useful adjunctive treatment for periodontitis in dogs.

In vivo administration of recombinant TNF-alpha promotes bone resorption in mice.

BACKGROUND: In vitro studies demonstrated that proinflammatory cytokine tumor necrosis factor alpha (TNF-alpha) modulates bone metabolism. OBJECTIVE: The aim of our study was to confirm the ability of TNF-alpha to induce osteoclastogenesis and bone resorption in an in vivo experiment, with the use of calvarial model in mice. MATERIALS AND METHODS: Twenty C57-Black mice were divided into four groups with five animals in each. The first group was infused subcutaneously on their back with recombinant mouse (rm) TNF-alpha via osmotic minipumps for 3 d, the second group was similarly infused with phosphate-buffered saline (PBS), the third group was infused with rmTNF-alpha to the region above the parietal bone and the fourth group with PBS in the same manner. Number of osteoclasts on parietal bone was determined morphometrically. Serum calcium and phosphates were monitored colorimetrically. RESULTS: Serum calcium level and number of osteoclasts on parietal bone were significantly greater after infusion of rmTNF-alpha above the parietal bone, whereas after subcutaneous delivery these parameters were similar to the control group. CONCLUSION: We are concluding that TNF-alpha has the ability to change the bone metabolism in a paracrine manner only.

Influence of subcutaneous administration of recombinant TNF-alpha on ligature-induced periodontitis in rats.

Proinflammatory cytokine tumor necrosis factor alpha (TNF-alpha) was found in inflamed periodontal tissues and many studies pointed to its significant role in development of periodontal disease. In this study, the influence of subcutaneously administered recombinant human TNF-alpha (rhTNF-alpha) on inflammatory reaction and periodontal breakdown in rats was analyzed during experimental periodontitis, induced by placing silk ligatures around the maxillary right second molar tooth. The rats were divided into two groups with five animals in each; the first group was infused subcutaneously with rhTNF-alpha via osmotic pumps for 2 weeks and the second group was infused with phosphate-buffered saline (PBS) in the same manner. Inflammatory reaction and periodontal breakdown was evaluated morphometrically on hematoxylin and eosin stained sections. Serum ionized calcium and inorganic phosphates were monitored colorimetrically. Serum calcium and phosphate levels were similar in rats receiving rhTNF-alpha and PBS. Ligation resulted in accelerated periodontal breakdown, while subcutaneous rhTNF-alpha administration by itself had no significant effect. Combined effect of subcutaneous rhTNF-alpha administration and ligation resulted in a significantly greater inflammatory reaction and periodontal breakdown then either treatment alone. We concluded that the subcutaneous administration of rhTNF-alpha accelerates the progression of experimental periodontitis in rats.