Histological Grounds of the Dental Implantation in Patients with Parodontal Diseases

UDC 616.314.17:611.018

I.Yu. Popovych, Т.OPetrushankoG.AYeroshenkoA.IYachmin

Ukrainian Medical Stomatological AcademyPoltava

Histological Grounds of the Dental Implantation in Patients with Parodontal Diseases

ivanstomat@ukr.net

The paper has been written within the research work, entitled “The mechanisms of influence of pathogenic factors on dental status of individuals with somatic pathology, ways of its correction and suppression” (State registration No. 0115U001138).

Currently, periodontal tissue diseases are ranking high among all dental diseases and its incidence increases annually. Generalized periodontitis, manifested by symptomatic gingivitis, progressive bone resorption, periodontal pockets, and pathological tooth mobility, which in turn leads to premature tooth loss, accounts for the largest ratio of this group of diseases [ Popovych IYu, Petrushanko TO. Obiektyvizatsiia stanu parodonta ta stupenia rukhomosti zubiv. Visnyk problem biolohii i medytsyny; 2016, 1(127): 258-60.].  According to the WHO’s reports, in young people, generalized periodontitis ranks second after dental caries, and ranks first in people after 40 years old [Gromov OV. Sravnitelnaya harakteristika indeksov sostoyaniya parodonta v vozrastnom aspekte. Sovremennaya stomatologiya; 2012, 4:16-9].  The issue of direct bonding in this category of patients is relevant to date, especially in cases of bounded edentulous spaces.

Direct bonding of single bounded edentulous spaces is possible in several ways. This includes manufacturing of adhesive dental bridge, metal-ceramic dental bridge, or installation of dental implant. The main method of restoration of bounded edentulous spaces in patients with generalized periodontitis is prosthetics with dental bridges [Prots HB. Suchasnyi pohliad na problemy dentalnoi implantatsii u khvorykh na heneralizovanyi parodontyt. Halytskyi likarskyi visnyk; 2013, 3(20): 74-6]. However, this method leads to overload of supporting tissues in this category of patients.

Currently, the most optimal way to restore the bounded edentulous space is the method of dental implantation. This method promotes rational distribution of the chewing load on the dentition, creating the conditions for achieving long-term remission and stabilization in periodontal tissues. However, parodontal patients are in the risk group during dental rehabilitation [Hasiuk NV, Yeroshenko HA. Zastosuvannia morfolohichnykh metodiv doslidzhennia u diahnostytsi ta prohnozuvanni klinichnoho perebihu heneralized parodontytu. Metodychni rekomendatsii. 2015. 22.].    

PurposeThe paper was aimed at determination of the structural features of the tissues, surrounding Alpha dent active dental implants, associated with diseases of porcine periodontal tissues.

Methods and Material  

The study was carried out on 10 castrated male pigs of the Ukrainian big white breed, weighing 70 + 4,5 kg, aged 6 ± 1 month old, individually kept on the conventional system of breeding (twice-daily standard dry-food feeding with free access to water) at the Institute of Pig Breeding and Agricultural Production of the National Academy of Agrarian Sciences of Ukraine. The experimental study was performed in several stages. At the first stage generalized periodontitis was simulated using our own methodology. It involved destruction of the dentogingival junction using micro-abrasor and insertion of crushed tartar into the created periodontal pocket with its subsequent closure with liquid composite material. Following three weeks the development of generalized periodontitis in pigs was ascertained.

At the next stage, we performed tooth extraction in a pig with simultaneous replacing the missing tooth with Alpha dent active dental implant. Following 3 months, the animals were sedated with ketamine (5 mg / kg intramuscularly). The extracted fragments of jaws with implants were placed in 10% buffered formalin for 24 hours, subsequently subject to acid-free decalcification. A month later, the implant was gently twisted; the material was embedded in paraffin according to the conventional technique [Bagri MM, Dibrova VA, Popadinets OG, Grishchuk MI. Methods of histological research monograph; in a row. Bagriya MM, Dibrovy A. Vinnitsa: New Book, 2016: 328 pp.] and sections of 5 μm thick were made, stained with hematoxylin and eosin.

All animals had no clinical signs of infection or any other oral diseases. Experimental manipulations have been made in compliance with the requirements of international principals of the “European Convention for the Protection of Vertebrate Animals Used for Experimental and Other Scientific Purposes” (Strasbourg, 1986) and “General Ethic Rules for Conducting Experiments on Animals”, adopted by the I National Congress on Bioethics [Obschie eticheskie printsipyi eksperimentov na zhivotnyih: materialyi I Natsionalnogo kongressa po bioetike. 2001. – K.: NANU. – 16 c.], and the requirements of the “Procedure for conducting tests, experiments on animals by research institutions” (2012).

The study and imaging of the sections was made on the Biorex–3 ВМ–500T microscope equipped with DCM-900 digital microphoto attachment with software adapted for the studies in 400×magnification. 

The morphometry was used in determining the dimensions of the diameters of the vascular lumens, namely, arteries, arterioles, capillaries, venules, veins, as well as the dimensions of bone fragments [Yeroshenko GA, Kostilenko Yu. Correlation between the morphometric indices of the large salivary glands of rats is normal and after stimulation of the peripheral nervous system. The world of medicine and biology; 2009, 3: 64-70. ]. The amount was recorded in absolute figures and mean values were calculated in Exel software  

Results and Discussion

The study of histological sections revealed the direct contact of thin layer (519.35 ± 6.17 μm) of dense connective tissue with the dental implant (Table 1).

Table 1

Metric values of tissues surrounding the dental implants (μm)

Thickness of connective tissue

Superficial osseous fragments

Deep osseous fragments

Thickness

Length  

Thickness

Length  

519,35±6,17

84,86±1,78

372,42±3,99

321,15±3,91

378,63±4,01

 

Thick collagen fibers formed bunches and the amount of cellular elements was small (Fig. 1a). The study of serial sections showed that collagen bunches had oblique-circular path, forming spiral structures.

Migrant connective tissue cells, mainly macrophages and lymphocytes, were visualized perivascularly near the vessels with high hydraulic permeability of the wall, i.e., venules and capillaries (Fig. 1a). Capillary-type vessels were determined in superficial dense connective tissue layers, adjacent to the dental implant, forming the loops. Arterioles and venules were localized in deep layers in close proximity to the osseous tissue (Fig. 1b). Their wall had a classic structure and blood corpuscles were determined in the lumens.

Bone trabeculae

Bone trabeculae around the dental implant

Fig. 1. Dense connective tissue and the vessels of the microvasculature. H&E stain. 400×magnification.

 

The arteries and veins were found behind a layer of bone trabeculae in a dense fibrous connective tissue. Morphometric study showed that the mean diameter of the arteries was 28.06 ± 0.24 μm, the resistive section of the microvasculature – 15.15 ± 0.05 μm, the exchange section (capillaries) – 7.56 ± 0.04 μm, the exchange section (venules) –18.30 ± 0.10 μm and veins – 35.13 ± 0.24 μm with no significant difference from the values for the intact periodontium (Table 2).

Table 2

Mean values of the diameter of the vascular lumen of tissuessurrounding the dental implants (μm)

Arteries

Arterioles

Capillaries

Venules

Veins

28,06±0,24

15,15±0,05

7,56±0,04

18,30±0,10

35,13±0,24

 

The study of histological sections of fragments of porcine jaws has revealed newly-formed bone fragments behind the layer of dense connective tissue, which were formed by direct osteogenesis, i.e., osteoblasts were located outside, and osteocytes were determined in the osteoid. The shape of the fragments was elongated. The mean dimensions were 84.86 ± 1.78 μm by 372.42 ± 3.99 μm, which was 1: 4.4 (see Table 1).

They were oriented to the edge of the canal at an angle of 450 and tiled over one another, separated by thin layers of dense connective tissue (Fig. 2a).

Bone trabeculae around the dental implant

Bone trabeculae around the dental implant

Fig. 2. Bone trabeculae around the dental implant. H&E stain. 400×magnification.

In the deeper layers around the dental implant, the thickness of the dense connective tissue layer did not differ from the superficial ones. However, the dimensions of the bone fragments was bigger, sometimes having an irregular shape, which was caused by the conjoining of individual bone fragments and the formation of an array of osseous tissue around the dental implant (Fig. 2b). The morphometric study has found that their mean dimensions were 321.15 ± 3.91 μm by 378.63 ± 4.01 μm (see Table 1) and were 1: 1.2, thus obtaining a rounded shape that can be associated with conjoining of bone fragments on the lateral surfaces.

Thus, the findings of the study on the peculiarities of the structural organization of the tissues surrounding the Alpha dent active dental implant has revealed the formation of a conglomerate formed by a combination of dense fibrous well-vascularized tissue and osseous tissue following three months after its installation. At the same time the dynamics of increase in the volume of the newly formed bone and increased strength of the dental implant fixation in the jaw was noted. The latter is confirmed by previously obtained data on high rates of stability of the used type of dental implant, compared with others [Popovych IYu, Petrushanko TO, Yeroshenko GA, Steblovskiy DV. Comparative analysis of dental implants stability. The world of medicine and biology. 2018; 4 (66): 191-4.].

Conclusion

The presented histological and morphometric study of the tissues surrounding the dental implant has established that, within three months, a complex of tissues was formed around the implant, which secure it in the jaw. From the primary dense connective tissue, which forms a dense network of blood vessels that activate the process of osteogenesis, only a thin layer remained. Externally, newly-formed bone fragments, conjoined in the depth of the canal and enlarged in size, were noted. Consequently, it can be asserted that the process of bone formation begins at the bottom of the canal, gradually spreading to the surface.

October 11, 2019
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