Specific aspects of the radiographic morphometric and densitometric characteristics of mandible of the rats with experimental diabetes mellitus after tooth extraction

Abstract

Diabetes mellitus is regarded today as a metabolic disease, which is considered to be a modulator of endodontic infections, is responsible for altering the immune and inflammatory responses, impedes the healing process, and contributes to damage of organs and tissues of the body, including tooth pulp and periapical tissues. The aim of the work is to study the radiographic characteristics of the dental septum of the alveolar crest of the mandible, crown and root of the low molars of rats with experimental streptozotocin diabetes at different times of the post-extraction period (the 1 st , 7 th and 14 th day). Materials and methods. Studies were conducted on 120 male Wistar rats, 8–10 months old, divided into eight groups of 15 animals each. The experimental diabetes mellitus was modelled in 45 animals by a single administration of streptozotocin interperitoneally (SIGMA Chemical, the USA) at a dose of 50 mg/kg, diluted in 0.5 ml of 0.1 M citrate buffer (pH 4.5) ex tempore, on the 21 st day after its induction the level of fasting glucose was determined (by the glucose oxidise method using standard test strips Test Strip II, glucometer Glucocard, Japan), which was 24.7 ± 2.2 mM/l. The extraction of the first low molar of the right mandible was realised using thiopental anaesthesia (40 mg / kg dose) with additional local infiltration anaesthesia with Ubistesine (3M Deutschland GmbH, Germany).On the 1 st , 7 th , and 14 th day, dates that correspond to the experiment after the extraction of the tooth, the rats were decapitated using thiopental anaesthesia (dose 40 mg/kg).The visiography of the mandible was performed using a computerized 3D CBCT tomograph Panoura 18S Panoramic 3D. With the help of digital image analysis the radiographic density of tissues of the alveolar socket of the removed 1 st molar, crown of the 1 st , 2 nd and 3 rd molars, their root and dental septum of the alveolar crest were determined. The results. Radiological density of the interalveolar and interradicular septa between the 1 st –3 rd molar and the 1 st molar root, which is the most traumatized and loaded rats' tooth, is decreased in the rats with experimental diabetes mellitus. Tooth extraction in the rats with diabetes mellitus results in the increase (not in the decrease as it is observed in control group) of radiological density a day after in the alveolar socket and the adjacent 2 nd and 3 rd molars, that may be caused by significant infiltration related to the secondary alteration. The final stage of the local inflammatory reaction resorptive phase that corresponds to the 7 th day of post-extraction period is characterized by almost complete restoration of the alveolar socket radiological density in the control rats, whereas in the rats with diabetes mellitus radiological density of the studied sites decreases and this process continues on the 14 th day. C onclusions. In the work it was found out that the extraction of a tooth in rats with normal carbohydrate metabolism is accompanied by dynamic changes in radiological density not only in the extraction area of the 1 st molar (it decreases on the 1 st day in the area of the root more than 2.7 times and by 65 % in the area of interalveolar and interradicular septa with its restore to the 14 th day), the inflammatory process affects the adjacent 2 nd and 3rd molars, leading to its decrease on the 1 st day in the area of interalveolar and interradicular septa of the 2 nd molar by 24.4 % and 3 rd molar – by 16.8 % with its restore to the 7 th day. It was revealed that the pre-existing early resorptive phase of the local inflammatory reaction ends by the 7 th day of the post-extraction period, changing to the reparative by the 14 th day. The development of experimental diabetes mellitus in rats leads to an increase in resorptive processes in the mandible bone tissue, which is manifested by a decrease in radiological density in the area of the 1 st molar root by 2.27 times along with its increase in the interalveolar and interradicular septa area of all three low molars by 22.0 %, 21.8 % and 18.3 %, respectively. Experimental diabetes contributes to the particular course of the wound process after tooth extraction. At the same time, it is an important pathogenetic link for the formation of complications due to the disturbance of the resorption-reparative relationship in the area of the alveolar socket and the adjacent molars.