Periodontitis is characterized by periodontal tissue destruction, including the alveolar bone. One of its critical components is the release of pro-inflammatory neuropeptides from sensory nerve endings innervating the periodontium. Since nerve growth factor (NGF) has been reported to up-regulateneuropeptides in sensory neurons, we hypothesized that it would be increased in ligature-induced periodontitis in rats, and that systemic NGF neutralization would reduce the periodontitis-associated alveolar bone resorption. Real-time PCR analysis disclosed a statistically significant time-dependent up-regulation of NGF mRNA in gingiva during 2 weeks of periodontitis. Interestingly, NGF up-regulation was also detected in the contralateral gingiva. In addition, immunohistochemistry of trigeminal ganglion neurons innervating the gingivomucosa demonstrated increased expression of TrkA receptor for NGF. Systemic anti-NGF treatment during periodontitis significantly reduced interleukin-1beta expression in gingiva and bilateral alveolar bone resorption. This suggests that NGF promotes periodontal inflammation and implicates a possible use of anti-NGF treatment in periodontitis.
COBISS.SI-ID: 26759641
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.
COBISS.SI-ID: 30370777
The aim of this study was to evaluate the use of magnetic resonance imaging (MRI) as a noninvasive method for the characterization of the inflammation and healing processes in periodontal tissues. Methods; For the in vitro study, 99 gingival samples were collected during periodontal surgical treatment and T1 relaxation time measurements were performed and correlated to the probing depth measurements recorded at the site of the collection. For the in vivo study a group of eight patients with moderate to advanced periodontal disease was examined by pre-contrast and Gd-DTPA contrast enhanced T1 weighted MRI before and three months after the non-surgical periodontal therapy. On MR images of 8 patients, 53 regions of interest (ROI) were selected. For each ROI, the ratio between post- and pre-contrast signal intensity (RSI) was calculated and used as a measure for the degree of the inflammation. The in vitro T1 relaxation times measurements of gingival samples showed an increase in relaxation times with the increase of probing depth (PD) at the sites of tissue removal. The in vivo studies demonstrated that the reduction of inflammation and PD in gingival tissues after the non-surgical periodontal therapy correlates with a decrease of RSI in T1 weighted MR images. The non-invasively obtained data provide the characteristic ratio U, which shows that two distinct types of inflammation occurred in the examined group of patients.The results of MRI provide a new possibility to characterize the type and healing process of periodontal inflammation.
COBISS.SI-ID: 22640679
Endothelins (ET)-1, ET-2, and ET-3 are one group of cytokines likely to be released during orthodontic tooth movement (OTM). Therefore, the expression ofET levels was investigated to determine the importance and involvement of isopeptides during the several phases of OTM. Thirty-two male Wistar rats (12-13 weeks old) were divided into four groups of eight: control, 14, 28, and 42 day groups. Tooth movement was induced by a closed-coil spring insertedbetween the upper left first molar and the upper incisors. The distance between the teeth was measured on days 0, 2, 7, 14, 21, 28, 35, and 42 using a digital calliper. The rate of tooth movement was calculated. The animals were sacrificed on days 14, 28, and 42 and gene expression levels of all three ET were determined using reverse transcription polymerase chain reaction. Statistical analysis was performed using two-way analysis of variance, Bonferroni's correction, and paired t-tests. The distance between the teeth decreased in all appliance groups (P ( 0.001). The rate of tooth movement was 0.20 +/- 0.02, 0.03 +/- 0.01, and 0.06 +/- 0.02 mm/day between days 0-2, 3-21, and 22-42, respectively. On day 14, gene expression levels forET-1 (P ( 0.05) and ET-3 (P ( 0.001) increased compared with day 0. On day 28, a downregulation of ET-3 was observed when compared with day 0 (P ( 0.001). On day 42, ET-1 (P ( 0.001) and ET-3 (P ( 0.01) gene expression levelswere strongly upregulated, while ET-2 gene expression level was downregulated (P ( 0.01) when compared with day 0. ET-1 and ET-3, but not ET-2, are involved in all three phases of OTM, and ET-1 seems to be the predominant form in the late phase of OTM.
COBISS.SI-ID: 27069401
Objectives: The aim of this study was to evaluate the effect of exposure time and image resolution on fractal dimension (FD) of periapical bone on images obtained using a storage phosphor plate (SPP) system. Materials and methods: Periapical images of premolar and molar teeth on both sides of ten dry human mandibles were obtained with Digora Optime (Soredex Corp., Helsinki, Finland)SPP system. The SPPs were exposed with three exposure times (0.05, 0.12, and 0.30 s) and scanned immediately after exposure with high and super resolutions. FD was calculated using public domain software (ImageJ with FracLac plug-in) on two non-overlapping region of interest (ROIs) on premolar and molar periapical bone areas of each radiograph using differential box-counting method. The ROIs on corresponding images were of the same size and position. FDs were compared using two-way ANOVA and Tukey-Kramer multiplecomparison tests (p = 0.05). Results: Images obtained with super resolution scans gave significantly higher FD values compared to high-resolution scanning for all exposures (p ( 0.0001). FD values were decreasing with increase in exposure time for both resolutions (p ( 0.0001). The highest FD was found for images with super resolution and shortest exposure time, which exhibited the highest noise. Conclusions: FD analysis seems not so robust method as it was believed previously. It shows significantchanges with image resolution and exposure time. Clinical relevance: Exposure time and scanning resolution of SPPs should be carefully chosen when evaluating the change in FD of alveolar bone for various bone disorders.
COBISS.SI-ID: 29577945