Methods of fitting dentures in elderly patients with complete lower jaw adentia using implants based on mathematical modeling

Рассмотрены вопросы лечения больных старческого возраста с полной адентией с использованием имплантатов. На основе математического моделирования дополнен алгоритм протезирования. Проведен анализ напряженно-деформированного состояния костной ткани нижней челюсти с опорой несъемного протеза на 4 винтовые дентальные имплантаты с учетом податливости слизистой оболочки тканей протезного ложа и обоснованием использования амортизирующих абатментов. Рассмотрены результаты взаимодействия съемных протезов с тканями протезного ложа, предложены рекомендации по применению. Розглянуті питання лікування хворих похилого віку з повною адентією за допомогою імплантатів. На основі математичного моделювання доповнений алгоритм протезування пацієнтів. Проаналізований напружено-деформований стан кісткової тканини нижньої щелепи з опорою незнімного протеза на 4 гвинтові дентальні імплантати з урахуванням податливості слизової оболонки тканин протезного ложа й обґрунтуванням використання амортизаційних абатментів. Наведені результати взаємодії знімних протезів із тканинами протезного ложа, запропоновано рекомендації щодо застосування. The complete absence of teeth often leads to a decrease not only the vital functions (chewing, speech function), but also significantly affects the socio - psychological scope of the patient. Advancing age determines the main feature and the complexity of orthopedic dental treatment in this group of patients due to lower adaptive capacities of the organism appearing in these age-related changes and disorders. Despite the achievements in medical rehabilitation of patients with a complete lack of teeth, it is not settled the question of Prosthetic Dentistry. The urgency of this problem also undeniable that, according to the World Health Organization, about 26% of patients do not enjoy full removable rotezamy different reasons. This is especially true for patients with totally edentulous mandibular prosthesis in cases of difficulty complete dentures due to lack of adequate fixation and its stabilization. One of the most effective methods of improving fixation and stability of the prosthesis is the installation of implants. However, in elderly patients with the use of implants anatomical and physiological features of tissues of the oral cavity and the presence of somatic changes in the body are decreased. The factors that determine the rationality of functional load transmission is primarily related stress that occurs in the bone around dental implants The purpose of this biomechanical study is to analyze the stress-strain state of bone tissue of the lower jaw with the support of non-removable prosthesis 4 screw dental implants based on compliance mucosa tissue prosthetic bed and justification for the use of shock absorbing abutments. Materials and methods. Mathematical modeling was performed using the well-known package modeling and finite-element analysis NASTRAN, designed for implementation in the Windows environment on a PC. Analysis of mathematical models based on finite-element procedure involves displacements of each node finite element in three coordinate axes, normal and shear stresses and the equivalent voltage Huber-Myzesu. The maximum values of equivalent stresses in cortical and spongy tissues of the jaw bone arising in areas of immediate contiguity to the mesial implant located on the oral side and correspond to the location of the food bolus central incisors. Since moving distally functional load on the alignment load placed mesial implant, and therefore the value of the equivalent stresses in cortical and spongy tissues of the jaw bone is gradually reduced, while the load is perceived extreme distally positioned implant and the value of the equivalent stresses in cortical and spongy tissues of the jaw bone adjacent to the last implant gradually increase and reach maximum values under 43.7 MPa and 9.77 MPa in the localization of functional loading on the second premolar. Further distal movement of the load along functional dentition reduces the value of the equivalent stresses in cortical and spongy tissues of the jaw bone adjacent to both average and extreme implant through the transfer of most of the functional load on the soft gum tissue. The maximum values of equivalent stresses in cortical and cancellous layers adjacent to the extreme central jawbone implant by varying the compliance of supporting gum tissue under saddle complete denture vary considerably smaller than in the case of hard abatmentov. Thus the absolute values of equivalent stresses in cortical and cancellous layers jawbone case with shock absorbing abutment, with varying degrees of support compliances gum tissue below the corresponding limits of strength. With a large supporting gum tissue pliability maximum values of equivalent stresses in cortical and cancellous layers adjacent to the extreme central implant jawbone using cushioning abutments half the size of similar values that arise when the prosthesis is based on four implants with rigid abutments