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10MEDICAL SCIENCES
INFLUENCE OF THE MATERIAL FROM WHICH THE GUM SHAPER IS MADE ON THE AMOUNT OF BACTERIAL COLONIZATION IN THE AREA OF FORMATION OF THE GUM
CONTOUR OF THE INSTALLED IMPLANTS
Jafarov R.,
Doctor of Philosophy in Medicine Head of the Department of Dentistry Faculty of Medicine, Nakhchivan State University Nakhichvan. Azerbaijan Aliyev V.
Doctor of Philosophy in Medicine, teacher of the Department of Dentistry Faculty of Medicine, Nakhchivan State University Nakhichvan. Azerbaijan
Abstract
One of the modern methods of orthopedic treatment of partial and complete absence of teeth is dental prosthetics using dental implants. Dental implants have become an integral part of modern dentistry and have significantly expanded the range of possibilities for restoring the dentition. Removable orthopedic structures, in comparison with non-removable ones based on dental implants, have a number of disadvantages due to the nature and type of fixation, the volume of plastic in the oral cavity, the time of adaptation to prostheses, as well as a low indicator of the aesthetic component and chewing efficiency. When forming the gums, the material from which the shapers are made is important. The main requirements for materials are strength, biocompatibility, non-toxicity and hypoallergenicity.
Keywords: gum former, dental materials, titanium, PMMA plastic, PEEK polymer
The presence of various prosthetic structures in the mouth leads to a change in the biocenosis of the oral cavity.
When conducting orthopedic treatment, it is necessary to take into account the degree of colonization ability of the resident microflora of the mouth when using various structural materials used in dental practice [1, 2, 7]. High microbial contamination of these materials can contribute to the development and maintenance of a local inflammatory process in the area of the dental implant suprastructure [3,4, ]. An important role in achieving an excellent functional and aesthetic result is played by the presence of healthy soft tissues in the implant area. Individual gingiva formers, which prepare the gingiva contour for abutment and crown installation, form the correct soft tissue eruption contour and are necessary to ensure implant stability and protect the peri-implant zone from infections [5,6].
In the works of domestic and foreign authors, it was found that for the colonization of artificial crowns, gum formers and other elements of orthopedic structures by microorganisms, the material from which they are made, the structure of its surface, the degree of polishing, physical, chemical and mechanical properties are important [8, 9 ]. However, to date, there are no recommendations on the use of one or another material for the manufacture of individual gum formers in patients with dental implants [10]. The purpose of the study: to conduct a comparative assessment of the degree of microbial contamination of the surface of structural materials used to form the contour of soft tissues in the area of dental implants.
MATERIALS AND RESEARCH METHODS
Orthopedic treatment was carried out in 36 patients aged 24 to 65 years, who were fitted with dental implants and, subsequently, individual gum formers. The patients were divided into 3 groups of 12 people each. For patients of the 1st group, the gum formers were made of titanium; for patients of the 2nd group -from PMMA plastic (polymethylmethacrylate plastic) and for patients of the 3rd group - from PEEK polymer (polyetheretherketone). Microbiological examination was performed twice: 7 days later (baseline examination) and 4 weeks after the installation of an individual gingiva former for the patient. The species and quantitative composition of facultative opportunistic microflora was determined from the surface of individual gum formers. After removing the gum shaper from the mouth, it was placed in a sterile Petri dish. A self-adhesive film was used to collect plaque from the surface of the gum formers. The film with fixed microorganisms was placed in phosphate buffer and homogenized. Decimal dilutions were made from the obtained suspension and cultures were carried out on blood agar, yolk-salt agar, MRS, Sabouraud agar, and chromogenic agar for primary identification and counting the number of grown colonies of microorganisms. The crops were cultivated according to the standard method in a thermostat at a temperature of 37 g. C for 24-48 hours under microaerophilic conditions. The number of microorganisms (CFU) was presented as decimal logarithms per 1 cm2 (lg/cm2).
RESULTS OF THE STUDY
During the background examination, the main spectrum of isolated microorganisms from the surface of the gum formers was represented by various facultative types of microorganisms. A significant number of isolated strains are representatives of the normal micro-bial flora of the mouth. It has been established that gum formers made of PMMA plastic are most susceptible to colonization by oral microorganisms. Enterococci, fungi of the genus Candida and actinomycetes on plastic molds accounted for more than 40%. Shapers made of titanium were the least affected by colonization. An intermediate position in terms of the degree of colonization was occupied by shapers made of polyether-etherketone polymer. The most pronounced differences in the degree of contamination of materials in yeast-like fungi of the genus Candida and actinomycetes. If fungi of the genus Candida were isolated from the surface of molds made of PMMA plastic in 43.8%, and actinomy-cetes - in 42.9%, then from the surface of titanium -only in 18.8% and 23.8% of cases, respectively. Fungal colonization of polyetheretherketone gum formers was 37.5% for fungi of the genus Candida and 33.3% for actinomycetes. It should be noted that only Psedomo-nas spp., Klebsiella, E. coli were isolated from the surface of PMMA plastic formers. These microorganisms are not typical of the oral microbiome. Once in the mouth, they are eliminated by antagonistic microflora or swallowed. However, given that PMMA plastic is a porous material, conditions are created for the fixation and accumulation of these microorganisms on the surface of the gum formers installed on dental implants. A quantitative characteristic of the composition of microorganisms isolated from the surface of the gum formers 7 days after installation is presented. A significant part of the isolated microorganisms were streptococci.
Among them, Str. mitis, Str. salivarius, Str. mil-leri, str. mutans. Their number did not exceed lg 3.4 CFU/cm2. Quantitative indicators 7 days after the installation of the gum formers had minor differences in the studied structural materials. The greatest differences were found when comparing two materials: PMMA plastic and titanium. For example, for fungi of the genus Candida, they amounted to lg 2.4 CFU/cm2 for PMMA, and lg 0.8 CFU/cm2 for titanium. PEEK polymer occupies an intermediate position. The number of microorganisms that colonized the surface of polyetheretherketone was, on average, somewhat lower than that of PMMA plastics and slightly higher than that of titanium. A re-examination of the studied parameters was carried out 4 weeks after the installation of the gum formers. Significant changes in percentage in the composition of the microbiome of the gum formers after 4 weeks of observation compared with the baseline data were not found. Streptococci colonized the studied materials in approximately the same way and accounted for 33.3%. Fungi of the genus Candida were isolated from the surface of PMMA plastic in 50% of cases, and from the surface of gum formers made of PEEK and titanium - in 30% and 20%, respectively. The same trend can be traced for lactobacilli and staph-ylococci. When determining the titer of microorganisms (CFU lg/cm2) that colonized the studied structural materials, after 4 weeks, significant changes were noted compared to the initial values. The largest number of the studied types of microorganisms was determined on
the surface of the gum formers made of PMMA plastic, and the smallest - on the surface of the gum formers made of titanium. Gingiva formers made of PEEK polymer occupied an intermediate position in terms of the degree of colonization of the surface of the gum formers by oral microorganisms. The results of the microbiological study convincingly indicate that the largest number of microorganisms were fixed on the surface of the gum formers made of PMMA plastic, including atypical representatives of the oral microbiocenosis. It is noted that individual gum formers made of PEEK polymer are slightly inferior in terms of the studied indicators to gum formers made of titanium. These results provide a basis for recommending the use of PEEK polymer for soft tissue contouring in the area of dental implants.
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