This article describes the surgical preparation and prosthodontic treatment of total edentulism and advanced bone atrophy followed by alveolar reconstruction with tibial autografts and the insertion of Anthofit implant-supported removable prosthesis on telescopic crowns and a zirconium framework (with the use of CAD/CAM technique and galvanoplasty).
Introduction According to statistics, 20% of Russia’s population under age 60 suffer from total edentulism.1 The quality of life of totally edentulous patients is significantly decreased. Edentulism inflicts a severe psychological injury on patients, and for many of them is associated with the loss of self-esteem because of embarrassment and discomfort. Edentulism results in pronounced esthetic disturbances: the height of the facial lower third decreases, occusal relations are compromised, the labial muscle tone decreases, the lips become narrower, and the face looks senile and unhappy. TMJ disorders and speech disturbances develop or exacerbate.
Traditionally, patients with total edentualism have been treated with removable prosthesis. In 2003-2006 the percentage of cases treated with removable prosthesis, compared to other treatment modalities, was as high as 50 to 70% in the Moscow region, according to the Moscow regional dental clinic.1 However, the performance of complete removable prosthesis has fallen short of desired; for example, virtually every prosthesis required repair and adjustments after 1 year of service, and the average longevity was less than 3 years.1 Removable prostheses further promote jaw bone atrophy and worsen the anatomical conditions. Traditional mandibular prostheses get often dislodged when buccal and hyoid-glossal muscles contract, therefore the teeth tend to be placed not in anatomically favorable position, but in neutral zones to stabilize the prosthesis. As bone atrophy advances, the height of the facial lower third decreases, and traditional removable prostheses serve, to increasingly larger extent, to maintain facial contours, thus they become bulkier and, as a consequence, less functional, less stable, and less retentive.
In recent decades, implant-supported prosthodontic restorations have proven to be a reliable, predictable, and effective treatment modality.2,3 Over the last 10 to 15 years, the survival rate for implants and implant-supported restorations has reached as high as 96 to 98%.2 Being inserted in jaw bone, the implant prevents bone atrophy and serves as a reliable abutment for a prosthesis. With the use of implant-supported prostheses, teeth can be set as required to fulfill esthetic and speech considerations. Implant-supported prostheses not only restore facial contours, but also provide stability, reproducible centric relation, excellent retention and masticatory efficiency. Masticatory proprioception doubles, and bite force increases by 85%. Speech improves, and clicking sounds typical for a traditional removable prosthesis user disappear.
Thus, implant-supported prostheses in patients with total edentualism have indisputable advantages over traditional removable prostheses. However, edentulism is associated with advanced bone atrophy, which counteract implant insertion without surgical preparation, which, in turn, can be very extensive.3 To perform alveolar reconstruction prior to implant insertion, many grafting techniques have been suggested (for example, tibial grafts, calvarium grafts, iliac grafts).
A fixed prosthesis has clear advantages (in terms of psychology and convenience of use). However, with advanced alveolar atrophy associated with total edentualism and the development of false ‘senile’ prognathism, fixed prosthesis has a number of disadvantages, such as lack of buccal and labial soft tissue support, speech disturbances, implant care difficulties, the development of frontal cantilever, poor load distribution, and long unaesthetic crowns.
Implant-supported removable prosthesis possess a few advantages, but in general patients like these prostheses less than fixed ones. In many respects, this is associated with the prosthesis mobility in the oral cavity.
This article presents an innovative approach to the fabrication of esthetic, comfortable, hygienic and light removable prostheses on telescopic crowns and zirconium frameworks and galvanic caps. With good retention, simple care and maintenance, and the precise fit of the components,4 a patient feels this prosthesis as fixed one.
Dr. Evgeny Zhdanov, Dr. Alexey Khvatov, Ilia Korogodin
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