"I solemnly swear to devote my life to serving humanity."

(Hippocrates III century BC, Oath of Hippocrates)

ArticlesOptimization approach to implant procedure

Optimization approach to implant procedure

V.G. Klуmentiev

European Dental Center, Kyiv, Ukraine

Summary. This paper offers the optimization methods of approach to the methodology of the implants placement into a tuberalpterygoid suture, improving planning processes till the implant placement and accelerating the process of osseointegration..

Key words: tuberalpterygoid suture, growth factor rich plasma, computed tomography.

Despite its rigidity, a bone is a system that is subject to changing forms, restructuring and reduction processes. On top of all, osteoblasts, osteocytes and osteoclasts are constantly involved in the coordinated activities that support the safety, renew and restore the intercellular matrix of the bone. This group of cells responsible for bone regeneration is known as the basic restructuring unit. The skeleton of the adult human body contains about 35 million of such restructuring unit, despite the fact that 3.4 million of these units are utilized every year it gives a vision of the intensity of cellular activity. Very often the patients who have atrophy of bone and need help go to dental clinics.

About 80% of the skeleton is composed of a cortical bone and 20% of a trabecular bone. When considering bone metabolism the difference can be told; despite the fact that the trabecular bone is a component in the minority, there is most intense metabolism in it, eight times more intense than in the cortical one. This is explained by the fact that the surface area and cellular structure of the cortical bone is much greater. Cortical bone predominates in the appendicular skeleton; its existence is typical for the diaphysis of long bones and the peripheral parts of short and wide bones; it withstands bending, turning and distributes power. An axial skeleton consists more of trabecular or spongy bone; it forms the central part of the short and narrow bones and designed to withstand pressure and compression forces act. Long bones, for example, comprise cylindrical portions or diaphyses consisting of cortical bone; at the ends of the bone the diaphyses are expanding and moving into the region of trabecular bone, called the pineal gland, which is part articulated with other bones. On epiphyses cortical bone is covered with a thin layer of cortical shell for the distribution of mechanical load of the joints, but trabecular bone absorbs dynamic load.

Dental implants in the early stages of atrophy can stop the process of bone resorption, but, as a rule, patients seek care at the time when the atrophy of the alveolar process has reached a considerable size. The use of surgical procedures such as augmentation considerably increases the duration of treatment in this disease. It is because of this situation, patients make their choice in favour of dentures. In this situation it is possible to offer an alternative solution to the problem, which is less invasive and more effective. In such cases we can talk about how to install implants in tuberalpterygoid suture of the upper jaw and additional techniques that make this procedure safe and effective.

Even in the most advanced cases of atrophy the maxillary tuberosity always retains plot of the unresorbed bone. Anatomically a tuberalpterygoid suture connects the pterygoid processes of the sphenoid bone with the upper jaw. Attaching the masticatory muscles makes it possible to preserve and maintain the bone tissue in this area. Installation of implants in this area allows achieving maximum primary stability at the expense of immediate fixation in hard cortical boneon it is possible to offer an alternative solution to the problem, which is less invasive and more effective. In such cases we can talk about how to install implants in tuberalpterygoid suture of the upper jaw and additional techniques that make this procedure safe and effective.

Placing implants into the tuberalpterygoid suture makes it possible not to carry out the sinus lift operation, while minimizing the risk of surgical trauma. When planning the operation we used an additional diagnostic method - computed tomography, and during the operation - blood plasma rich in growth factors, as autotransplant material.

Computed tomography is a more professional and modern kind of jaw research which usually refers to additionally appointed studies in cases where a conventional panoramic picture is not enough.

Computed tomography of the jaw is a three-dimensional image layer by layer which allows us to estimate the anatomical features of the structure of teeth, roots and root canals, and most important - to determine accurately the amount of bone necessary for implant placement, to simulate the position of the installed implant in the bone structure and to calculate its exact location and the direction in the jaw.

An implantologist immediately obtains quite a few significant advantages:

• diagnostic accuracy - computer tomography allows to obtain an unlimited number of slices for calculating the thickness and the height of the bone needed for installing and fixing the implant;

• guaranteed result - three-dimensional model of the jaw several times increases informative value of the study, so the doctor is able to build a treatment plan in the most effective way.

Computed tomography also involves modelling the step-by-step process of the implant installation on a computer and gives the patient the opportunity to evaluate the intended result before the start of the operation.

Tissue recovery process is based on a complex sequence of biological phenomena which are controlled by a long list of biologically active growth factors and proteins. Spatial and temporal effects of this family of mediators in the damaged tissue and adjusts the mechanisms and phases that control the tissue recovery and regeneration. For example, in the case of bone regeneration the primary purpose to develop local growth factors is stimulation of osteoprogenitor cells admission to the site of injury and subsequently direction in a certain way their differentiation towards osseogenesis. Throughout this process, a number of other factors will regulate the dynamic equilibrium intercellular inhibition and proliferation as well as angiogenesis and the formation of extracellular matrix.

This means that functional reconstitution of tissues depends on a number of stages or phases, which are controlled by a large number of biological mediators that, in turn, appear and act in time and space. This definitely is a duality of growth factors which are responsible for the final analysis of the tissue development correctness, which is why there was a desire to understand better this phenomenon. A detailed study of regenerative tissue processes led to the discovery of the importance and fundamental role of platelets in this context. Platelets can serve as physiological reservoir of the growth factors and proteins, that is, functional units, of potential interest to which lies in their biological mediator composition. Technology for producing plasma rich in human growth factors based on a careful study, use, preparation and activation of autogenic platelet-rich structure, which, among other things, is characterized by its biocompatibility and availability.

A detailed study of the characteristic properties of platelets on a par with the optimized conditions of their concentration, activation and release of energy made it possible to develop a technology with great adaptability and therapeutic potential. Plasma rich with human growth factors is one hundred per cent autogenous platelet-derived product that has unique properties that makes it optimized for biological efficacy and biosafety.

Tissue regeneration involves a complex series of biological processes that are controlled by the interaction of a mixture of growth factors. There are three factors involved in tissue regeneration: cellular component, a combination of various biological mediators, which include growth factors, including cytokines and matrix or "skeleton", which provides structural support for the new tissue.

After injury or damage to the tissue they are activated and coordinate a set of intercellular or intracellular pathways to restore the structural integrity of tissue and haemostasis. Growth factors are also required to stimulate angiogenesis, or formation of blood vessels that will supply oxygen and nutrients to the area of tissue injury. Another fundamental aspect to consider in the perspective of tissue regeneration is the formation of "skeleton", which acts as a temporary extracellular matrix and, consequently, distributes the cells so that they reproduce their biochemical, structural and physical impulses that provides fixation of the mechanisms of cell motility..

It is these positive properties of plasma rich with growth factors can be used to insert the implant into the tuberalpterygoid suture to improve and accelerate the process of osseointegration.

The surgery is performed under local anaesthesia. All the rules and regulations of the protocol of setting of one-stage implants have been complied with. Suture marks were determined by clinical parameters after inspection and palpation, and after the preliminary computed tomography. Choosing the installation location of the implant, it is necessary to draw two imaginary lines: line "A" is a conditional perpendicular line drawn from the projection of large palatal openings to the intersection with the line "B". line "B" is an imaginary line connecting gamulus lamina pterygoideainternaossphenoidale to the base of the ridge.

This point is a place the implant insertion. Pilot drilling and implant placement should be performed straight up and behind the hill of the upper jaw. Using a flapless technique practically did not violate the tissue trophism, regeneration processes ended in a short time by using the above plasma rich with human growth factors.

Clinical case No.1

Patient M. came to the clinic complaining of partial absence of teeth in the upper and lower jaws. After CT studies a significant atrophy of the alveolar process of the maxilla has been detected (Fig. 1).

Figure 1 Panoramic shot of patient M before the surgery.

Panoramic shot of patient M before the surgery

It was decided to install one-stage implants tuberalpterygoid suture for the further fixation for subsequent permanent structure. Before installing the implants were treated with plasma enriched with human growth factors to improve osseointegration (Fig. 2, 3, 4).

Figure 2 Blood sampling from the patient M.

 Blood sampling from the patient M

Figure 3 Preparation of plasma rich with human growth factors.

Preparation of plasma rich with human growth factor

Figure 4 Processing the implants with plasma rich with human growth factors.

Processing the implants with plasma rich with human growth factors

After tooth extraction curettage holes using erbium laser was performed.

Before installing the implants an irrigation of the bone channels was carried out with 10% povidone-iodine solution.

Figure 5 Postoperative panoramic radiography of patient M.

Postoperative panoramic radiography of patient M

After 6 months, the next stage- permanent prosthesis was held.

Figure 6 Oral cavity condition before the prosthetics.

Oral cavity condition before the prosthetics

Figure 7 Production of metal-ceramic bridge on the upper jaw.

Production of metal-ceramic bridge on the upper jaw

Figure 8 Production of metal-ceramic bridge on the lower jaw.

Production of metal-ceramic bridge on the lower jaw

Figure 9 Panoramic image of patient M in 6 months after the surgery.

Panoramic image of patient M in 6 months after the surgery

Figure 10 Photo of the placed permanent porcelain fused to metal bridges. 6 months after the surgery.

Photo of the placed permanent porcelain fused to metal bridges

CONCLUSIONS

Application of sinus lift can be justified from the standpoint of creating an artificial additional bone volume in the lateral maxilla, but even with such indications sinus lift is evaluated negatively, especially by the patients, due to the invasiveness, the risk of infection of the graft, as well as the duration of the treatment. The technique of implant placement without sinus lift is much safer and more effective compared to the combined method of sinus lift and two-stage implant placement.

Surgical risk in interventions into tuberalpalatopterygoid area occurs due to the presence of vessels passing here (descending palatine artery and venous plexus). Data analysis performed on cone-beam tomography, is the aim of the search for the possibility of installing dental implants to bypass the important anatomical structures on the upper and lower jaws with a deficit of bone tissue in the planning stage.

It is generally accepted that the redistribution of occlusal forces should go to the opposite cortical plates. This is what led to the development and improvement of methods of implant placement into tuberalpterygoid area. Fixed in dense bone of the tuberalpterygoid suture one-piece implant can be loaded with a temporary prosthesis in two or three weeks. When using implants in the tuberalpterygoid area, as well as additional methods of the application of plasma enriched with human growth factors, the process of complete rehabilitation of the patient is reduced for many months.

The bone density in the area of the tuberalpterygoid suture is significantly higher than that of the alveolar bone.

The use of long implants in the side portions of the upper jaw with a minimum height of the alveolar ridge, fixed in the tuberalpterygoid suture, as well as the use of CT diagnosis in the planning of surgical intervention allows avoiding further trauma during the augmentation of bone tissue, as well as significantly reduce the treatment time by using plasma rich with human growth factors.