Periodontitis aggravates kidney damage in obese mice by MMP2 regulation.

OBJECTIVE:   To investigate the effect of periodontitis on the development of kidney damage in obese mice and its possible mechanism. METHODS:   C57 BL/6J mice were fed high­fat (HF) or low­fat (LF) diet and then divided into four groups:  obesity with periodontitis (HFP), obesity without periodontitis (HFC), normal mice with periodontitis (LFP) and normal mice without periodontitis (LFC). Serum indicators of renal function, namely serum total protein (TP), albumin (ALB), creatinine (Cr) and blood urea nitrogen (UREA) were measured. The histopathological examination of kidney tissues was performed. The expressions of transforming growth factor-ß1 (TGF-ß1), matrix metalloproteinase-2 (MMP2) and tissue inhibitors of metalloproteinases-1 (TIMP1) were detected by immunohistochemistry and real time RT-PCR. RESULTS:   Obesity decreased TP and ALB, and increased serum Cr and UREA levels in normal and periodontitis mice groups, as well as induced glomerular and tubulointerstitial pathologic changes. Tubulointerstitial fibrosis was more severe in HFP group. In obese mice, periodontitis caused the downregulation of MMP2, and upregulation of TIMP1 and TGF-ß1 at transcriptional and translational levels. CONCLUSIONS:   In obese mice, periodontitis may aggravate pathological changes in the kidney. The possible mechanism might lie in downregulation of MMP2 and upregulation of MMP inhibitor, TIMP1, and TGF-ß1 (Tab. 1, Fig. 4, Ref. 16).

Histological changes within dental pulps in teeth with moderate-to-severe chronic periodontitis.

AIM: To investigate the effect of chronic periodontitis on dental pulps by assessing histological changes in the pulps of teeth with moderate-to-severe periodontitis. METHODOLOGY: A total of 242 teeth from 162 patients with moderate-to-severe periodontitis were collected, and histological changes in pulps were investigated by staining with haematoxylin and eosin. Baseline data were taken from the patients' records before extraction. The morphologic changes observed in the pulp were classified as degree I, degree II, degree III and degree IV. Statistical analysis of the severity of periodontitis and histological changes with the pulps was applied using the Mann-Whitney U rank sum test, whilst the contingency coefficient was used to analyse the inter-relationship between the severity of periodontitis and histological changes in the pulps. RESULTS: The inter-relationship between the severity of periodontitis and histological changes in the pulps was 0.274 (P < 0.001), and significant differences existed between teeth with moderate periodontitis and severe periodontitis group (Z = 4.145, P < 0.001). The inter-relationship between attachment loss and histological changes in the pulps was 0.397 (P < 0.001). There were significant differences in the histological changes amongst teeth with various degrees of attachment loss (χ(2) = 33.023, P < 0.001) and amongst teeth in different locations (χ(2) = 23.163, P < 0.001). CONCLUSIONS: There was a positive association between the severity of periodontitis and histological changes within the pulp. More attachment loss was correlated with pathological changes within the dental pulp.

[Strategies of periodontal surgery to promote orthodontic treatment: the clinical application of periodontally accelerated osteogenic orthodontics].

Orthodontic moving teeth are closely related to the health of periodontal support tissues, and the combined periodontal orthodontic treatment is becoming more and more normalized. Inflammation control is the prerequisite for orthodontic treatment in patients with periodontitis. For many adult patients, the long course of treatment and the risk of periodontal tissue damage during orthodontic treatment have gradually attracted the clinicians' attention. Periodontally accelerated osteogenic orthodontics (PAOO) is one of the surgical strategies by combining selective decortication with alveolar augmentation to promote orthodontic treatment. It is aiming to accelerate the movement of teeth for shortening the treatment course, to increase the bone volume for reshaping the alveolar bone and expanding the range of tooth movement and to reduce the risk of tooth movement beyond the "alveolar bone boundary" during orthodontic treatment. Based on the retrieve and review of current literature, this article will focus on how to design and implement PAOO surgery so as to maximize the effectiveness in clinical practice.

Association among interleukin-6 gene polymorphism, diabetes and periodontitis in a Chinese population.

OBJECTIVES: Diabetics significantly increase risk for periodontitis. Interleukin-6 (IL-6) gene polymorphism may play certain roles in the progression of periodontitis with diabetes. The purpose of this study was to assess the association among IL-6 gene polymorphisms, type 2 diabetes mellitus (T2DM) and chronic periodontitis (CP) in a Chinese population. MATERIAL AND METHODS: DNA was obtained from 159 patients with CP, 88 patients with T2DM, 110 patients with CP&T2DM and 135 control subjects. The -174/-572/-597 polymorphisms of IL-6 gene were investigated by restriction fragment length polymorphism of polymerase chain reaction products. The results were further confirmed by sequencing. Significance was set at P < 0.008 after Bonferroni correction. RESULTS: Among four groups, CP&T2DM group showed the lowest IL-6-572 CC genotype and C-allele frequencies (54.5% and 74.1%). In this regard, there were significant differences between CP&T2DM group and the control group [P = 0.006, odds ratio (OR) = 0.475, 95% CI: 0.279-0.808 and P = 0.002, OR = 0.502, 95% CI: 0.319-0.788 respectively]. Logistic regression with adjustment for age, gender, body mass index, smoking and stress showed no significant difference in terms of IL-6-572 genotypes (P = 0.058, OR= 0.523, 95% CI: 0.268-1.022). CONCLUSIONS: The IL-6-572 genotype and allele distributions are unique to subjects with CP&T2DM in a Chinese population.