The second part of the XX century can be described as the time of acute discussions and disputes between clinicists on reaction of tissue against introduction of an implant and definition of the safest level of its functional strain. The problem of functional strain under inter-bone implantation is urgent, as both approaches, delayed and early strain, have its positive and negative sides (V.N. Olesova, 1986, A.A. Kulakov, 2000).
Research objectives. Experimental-clinic approval of method of early functional strain under dental implantation.
Central scientific-research institute of stomatology and facial surgery has served as the basis for our research.
Clinical part of the work was carried out during treatment of 332 patients in age of 20–70 years, including 228 women and 104 men. Average age of male patients equaled 53 year, women – 49 years. All the studied have been split into two groups after placing implants: the 1st group (234 patients) was formed by patients who had been earlier exposed to functional strain, and the 2nd, control group (98 patients), were treated with traditional methods of implantation with teeth implants.
Operations of inter-bone implantation were carried out on both lower and upper jaw. Distribution of implants according to the selected scheme and their location is provided in table.
Distribution of implants according the selected system and localization
|
Implant location |
Bioimal-implant |
LIKO |
Astra-Tech |
Total |
|
Lower jaw |
221 |
27 |
25 |
273 |
|
Upper jaw |
254 |
19 |
27 |
300 |
|
Total |
475 |
46 |
52 |
573 |
Implants of domestic implantation system «Biomal-implant» have been placed.
While inspecting patients we considered a number of teeth lines defects, athrophy degree of bone tissue of alveolar sprout, volume and localization of the tooth line defect.
To define recommendations and limitations to carry out surgery of inter-bone implantation, patients were exposed to clinic-laboratory, radiological, and functional inspection.
During the initial inspection we considered ethiology of adention, as the cause of lack of teeth is an important characteristic that indicates a potential risk of complications and defines the treatment forecast. Diagnostic models of jaws and wax biting blocks were made before placing implants in order to define central occlusion. Diagnostic models were used to define implant position and show a patient the construction of the planned treatment method. Dynamic observations were carried out at the basis of clinic-radiographic and functional methods.
At the stage of preliminary inspection of patients who has visited the clinic, and also during the process of dynamic observation the main method of radiological study was orthopantomography (OPTG). OPTG was used at the first visit of a patient and also during control periods after tooth implantation. Data of this method provide us with a large volume of information on the condition of teeth, allow us to reveal the degree of vertical resorbtions of alveolar crest, define the location of major anatomic formations of lower jaw channel, upper jaw cavities, and the bottom of nasal cavities. Computer tomography (CT) was used as an auxiliary method.
Orthopantomographies were taken with facilities PM2002, «Kranex», in terms 60–65 kV, 7–10 mА, exposed during 10–12 seconds.
During the research we have analyzed the data of OPTG for all patients with early functional strain in early periods of study before implantation, and after 1,3,6, 12 months, peculiarities of bone tissue formation around the implant have been described.
The study of micro-circulation in area of dental implantation was carried out via method of laser doppler flowmetry (LDF) with an analyzer of capillary blood flow – LAKK-01. The condition of micro-circulation was evaluated according to the index of micro-circulation (M) that characterizes the level of capillary blood flow; parameter – σ that defines variability of erythrocyte flow and variation coefficient (Kv) that characterizes vasomotor activity of microvessels.
Ultrasound osteometry was carried out with echoosteometer EOM-02. Electromiography (EMG) of chewing muscles was carried out with neuromiostome. Evaluation of jaw alveolar part blood supply was taken with the method of rheography with the facility RPKA-02 (MEDASS). Besides, automated computer processing of main rheographic indexes (RI – rheographic index, IVT – index of vessel tone, FI – flexibility index, IPR – index of periphery resistance) were evalueted. Dynamic observations of LDF, EOM, EMG, RG were carried out before placing teeth implants, and after a day, and then after 3, 6, 12 months.
The taken experimental research has established that under simultaneous placing of screw implants with an early functional strain connection-tissue capsule grows fast around implants, compacts, and fiberizes, and then becomes thin. It testifies for a possible early rehabilitation of patients with partial and complete loss of teeth.
Under early functional strain in area of dental implants we observe formation of bone structures with their further differentiation that ends with compaction of new bone tissue. A presence of thin connective-tissue capsule around implants is a favourable factor that provides for softening in mechanic stress during early functional strain. According to the data of echoosteometry, echo-density of bone tissue grows gradually and restores in 6 months after inter-bone implantation new methodic.
Early functional strain of dental implants provides for a realization of chewing muscles. Normalization of coordinated relations in their work comes in 3 months due to an alteration in bio-electric activity of the very chewing muscles and temporal muscles. Dynamic of regional geodynamics indexed proves the adaptation to early functional strain and complete restoration of regional blood flow in the area of implants in 6 months.
Among patients of the main group a level of tissue blood flow, its intensity and vasomotor activity of micro-vessels has increased by 40–75 %. It testifies for a development of hype re mi a in micro-circular bed that cut off in 3 months.
According to clinic-functional research, the method of early functional strain under dental implantation is more effective, compared to the traditional one. It is linked to a strengthening in reparative processes in bone tissue.
At the foundation of the research results, we can recommend gradual implantation right after placing an implant: making of temporary implant construction of plastic directly after placing an implant; making permanent orthopedic construction.
Evidence for early functional strain with the method of dental implantation is: preservation of the volume of bone tissue of alveolar jaw sprout; partial and complete loss of teeth; absence of inter-occlusion height disturbance; presence of keratinized gum; a patient’s readiness to take part in post-surgery rehabilitation.
Contradictory evidence against early functional strain under dental implantation is: an expressed atrophy of alveolar sprout bone tissue; a mismatch between the axis of implant and the axis of metal-ceramic crown,; absence of keratinized gun; incorrect distribution of chewing strain over the implant, mostly horizontal; unsatisfactory hygiene of oral cavity.
Resume. The article represents results of research on approbation and evaluation of the efficiency of a new methodic of early functional strain under dental implantation.
The work was submitted to International Scientific Conference «Fundamental and applied research in medicine», France (Paris), 14-21, October, 2012, came to the editorial office on 19.09.2012.