The effect of zinc complex of N-isopropenylimidazole on the morphological characteristics of gum tissues in experimental endodontic-periodontal lesions in rats Authors

Introduction: Combined inflammatory and destructive processes affecting the dental pulp and tissues of the periodontal complex are among the most problem diseases of the dental system. Current therapy with use of available pharmacological agents does not always allow achieving the expected positive result. In addition, often the lack of information about morphological processes in the tissues of the dental system, in particular the gums, with endodontic-periodontal lesion (EPL) limits the ability of dentists to carry out targeted pharmacotherapy with both traditional and, in particular, new medications. The aim of the study was to evaluate the morphological characteristics of gum tissues in a therapeutic context of N-isopropenylimidazole zinc complex derivative in experimental endodontic-periodontal lesion in rats. Materials and Methods: A simulation of EPL in rats was performed in two ways: simultaneous induction of acute periodontitis and parodontitis by pulp extraction and natural infection of the pulp cavity, as well as by ligation of the necks of lower incisors. The research protocols included 5 groups of animals: 1st – intact group (control-1); 2nd – animals with simulated EPL (control-2); 3rd – animals with simulated EPL and treated with Metrogyl Denta® gel (M-D); 4th – animals with simulated EPL and treated with N–isopropenylimidazole zinc complex derivative gel under the laboratory code Pilim-1; and 5th – animals with simulated EPL and treated with the combination of M-D + Pilim-1. The gum of the lower incisors was taken for morphological studies. Slides were stained with hematoxylin and eosin. Computer morphometry was performed using the ImageJ software. Results and Discussion: The substances M-D, Pilim-1 and, especially, the combination of M-D+Pilim-1 (against the background of chlorhexidine bigluconate used as oral rinse) for 14 days in rats with simulated EPL cause a significant improvement of the morphological structure of the gum with minimal residual dystrophy and sclerosis. The combination M-D + Pilim-1 led to a 1.3-time increase in epithelial thickness, and a 1.5-time decrease in acanthosis depth in comparison with M-D, while the number of capillaries and their diameter had no significant differences. Compared with Pilim-1, the epithelial thickness increased 1.5 times, and the acanthosis depth and the number of capillaries decreased 1.6 and 1.4 times, respectively, whereas the diameter of the capillaries did not change significantly. The pronounced protective effect of the combination M-D + Pilim-1 on the morphological structure of the gingival mucosa of rats with simulated EPL may be associated with antimicrobial, anti-inflammatory, regenerating, angioprotective and antioxidant properties of both M-D and Pilim-1 separately, and, possibly to a greater extent, of the combination M-D + Pilim-1. Conclusion: The substances M-D, Pilim-1 and, especially, the combination M-D + Pilim-1 (against the background of chlorhexidine bigluconate used as oral rinse) for 14 days in rats with simulated EPL have a protective effect on the epithelial structure and the connective tissue of the proper mucous plate, manifested in active normalization of pathological changes and significant restoration of their organotypic structure

Comparative Efficiency of Removable Mini-Implant Retained Dentures Using Different Attachments in Edentulous Patients

Aim. To compare the efficiency of removable mini-implant retained dentures using different types of attachment.Materials and methods. The study included 51 edentulous patients. The patients were divided into three groups according to the attachment type and abutment shape: 1) ball-and-socket attachment, ball abutment (n = 26); 2) locator attachment, equator abutment, XiVE LOCATOR system (n = 14); 3) bar attachment (n = 11). Removable dentures were made of ordinary acrylic plastic. The placement of intraosseous dental implants with their sublingual engraftment was performed according to the traditional two-stage delayed-load procedure. The efficiency of implants was evaluated using the method of M.Z. Mirgazizov and the eponymous index. The dynamics of vertical bone resorption around implants was determined using dental panoramic radiography (6 months, 1 and 2 years after the treatment). A periotest was performed 6 months after the end of the orthopaedic treatment.Results. The one-year survival rate of implants reached 96.2% in group 1, amounting to 100% in groups 2 and 3. The two-year survival rate came to 92.3% in group 1, reaching 92.9% and 100% in groups 2 and 3, respectively. Inflammatory phenomena characteristic of peri-implantitis were noted one year after the implant placement in 7.7% (n = 2) of patients in group 1 and in 7.1% of patients in group 2, with no inflammatory phenomena being observed in group 3. Two years after the implant placement, peri-implantitis was observed in 19.2% and 21.4% of patients in groups 1 and 2, respectively, coming to 9.1% in group 3. The periotest revealed that six months after the placement, implant stability was higher in group 3 for both the lower and upper jaw (in comparison with groups 1 and 2), as evidenced by the shift in periotest values towards the negative part of the scale.Conclusion. The study revealed that bar attachment, as well as locator attachment (equator abutments), of removable dentures supported by mini implants is more efficient as compared to the ball-and-socket attachment