Agreement, correlation, and kinetics of the alveolar bone-loss measurement methodologies in a ligature-induced periodontitis animal model

Abstract

Periodontal research involves the use of animal models to better understand the biological processes of periodontal diseases and the potential of new or existing therapies. Currently, ligature-induced periodontitis in rats is the main model used in periodontal research, in this model, alveolar bone loss (ABL) is the main parameter evaluated by radiographic, morphometric, and histological techniques. Interestingly, although these methodologies are widely used, it is not totally clarified neither the kinetics of ABL over the induction time nor the agreement degree (repeatability and reproducibility) of these techniques. Objective: To characterize ABL kinetics at 0, 3, 7, 15, 30, and 60 days after ABL induction by ligature and to evaluate the intra- (repeatability) and inter-examiner (reproducibility) agreement and the correlation among the radiographic, morphometric, and histological methodologies. Material and Methods: 60 male Wistar rats with induced ABL were randomly divided into 6 experimental groups (n = 10 animals/group). After 0, 3, 7, 15, 30, and 60 days, the animals were euthanized and their hemimandibles were removed for ABL determination using radiographic, morphometric and histological techniques. Results: Radiographic and morphometric/linear techniques allowed the detection of statistically significant ABL on the third day, while histological and morphometric/area techniques could only detect ABL after the seventh day (ANOVA/Tukey, p<0.05). After the fifteenth day, except for histological analysis, the ABL was stabilized. Concerning the agreement of the methodologies, Bland Altman's test (intra and inter-examiner evaluations) showed no difference among the measurements (p>0.05). In addition, high correlations (Pearson's test, r2>0.9, p<0.05) were observed. Conclusion: The results indicated that the minimum time for ABL induction could vary from 3 to 7 days, according to the chosen analysis methodology. Agreement and correlation data support the comparison of results between studies with same induction time.

Ligature induced periodontitis causes atherosclerosis in rat descending aorta: an experimental study

“…Experimental periodontitis can be induced by placing silk or cotton ligatures around the crown of the maxillary or mandibular molars or inferior incisors [12,13,18]. The choice for these materials is that they are plaque retentive and the accumulation of bacteria causes inflammation which leads to periodontitis.…”

“…Developing an experimental model of periodontitis that initiates atherosclerosis in the aorta of rats is of great importance in finding ways to better understand the pathophysiology and the involvement of oxidative stress in both diseases. In the literature there are studies describing the experimental model of periodontitis using silk or cotton ligatures around the maxillary molars or lower incisors of rats [12,13]. No studies have used an orthodontic wire around the mandibular molars.…”

High-fluence low-power laser irradiation promotes odontogenesis and inflammation resolution in periodontitis by enhancing stem cell proliferation and differentiation

“…All rats were fed with the same food (at 8:00 a.m. and 8:00 p.m.). Rats in the HF-LPLI groups underwent surgery, followed by a 1-week 20-J/cm 2 HF-LPLI treatment for 1 h/day after local injection of 1×10 5 /ml stem cells in 100 μ l, followed by the in vivo bioluminescence imaging and H&E staining ( 42 , 43 ). The Height of bone regeneration was calculated as 8 mm−(a1 + a2 + a3)/3.…”

Identification of Genes Differentially Expressed in Simvastatin‐Induced Alveolar Bone Formation

“…Naturally occurring periodontitis causes short episodes of bone resorption on a highly variable timetable over decades, so experimental periodontitis (ExP) in the rat model is often used to cause measureable periodontal bone loss over a 1‐week period . Ligature‐induced periodontitis used in the current study has been shown to initiate an inflammatory infiltrate in the connective tissue between the sulcular epithelium and bone, composed primarily of the lymphocytes lineage .…”