A conditionally removable prosthesis on implants is one of the types of dental prostheses; it is fixed in the oral cavity on supports using inclined abutments and screws.
Thanks to the screw fixation, the prosthesis can be installed and removed quickly and without injuring the surrounding tissues. For this, special tools are used, the procedure can only be carried out by a specialist in dentistry at the reception. It is necessary to separate the structure from the supports for hygienic cleaning, during examination of the gums or during treatment.
Types of Conditionally Removable Prosthesis on Implants
In dentistry, there are several types of implant prostheses – fixed, removable and conditionally removable. The division between them is in the way of fastening. As a rule, cemented implant crowns are referred to as fixed prostheses. They consist of zirconium, ceramic or metal-ceramic teeth – single crowns or dental bridges. Removable dentures are fastened with locks or buttons, since they can be removed from the oral cavity on their own. Constructions that can be easily removed from the oral cavity are considered to be conditionally removable, but only when using dental instruments. The separation of all these types is relative, since when using implants, they all create a reliable fixation of the prosthesis, do not allow the prosthesis to move or fall out when worn, it is not recommended to remove them yourself, and if necessary, the dentist can separate any structure from the implants.
In this article, we will consider the types of prostheses with fixation on screws and a bar base, which are removed only at the reception, indications for installation, stages of implantation and prosthetics, pros and cons.
Types of conditionally removable dentures:
- All-on-4;
- All-on-6;
- Segment prosthesis with partial adentia;
- Fully edentulous full-coverage denture.
Read also: Implant-supported Denture.
All-on-4
All-on-4 is a four-implant denture with a titanium bar and screw fixation. Installed according to the immediate loading protocol, the prosthesis is fixed within three days after the operation. According to the technology developed in 1998 by Nobel Biokear, the anterior implants are inserted vertically parallel to each other, the lateral ones at an angle of 45 degrees. Such an arrangement within the bone tissue allows to increase the area of the implant-jaw connection, to increase the degree of fixation in the chewing region, and to bypass the anatomical structures.
Thanks to modern technologies and high diagnostic accuracy by an implantologist and a prosthetist, it is possible to achieve high aesthetics, patient comfort and minimal tissue damage. However, the support of four implants is less reliable and stable, especially if there are signs of atrophy, in the presence of which the prosthesis may be contraindicated.
All-on-6
All-on-6 is a six-implant, screw-retained, complete covering prosthesis with an instantaneous loading protocol. The improved technique of prosthetics on implants has been used in Russia for the last 10 years, and has a number of advantages over the All-on-4 system. Thanks to 6 supports, the prosthesis can withstand a large load, it can be installed with a moderate degree of atrophy, fixation in the lateral section is more reliable, since the edge has an additional implant in the distal section.
New developments of the company make the system more flexible, and the individual approach and growing experience of doctors increase the quality of the All-on-6 installation. High requirements for the equipment of the clinic and the skills of doctors allow Nobel Biokear to remain the market leader in conditionally removable prosthetics. The disadvantage of the system is the high price and complexity in choosing dentistry – not every clinic meets the standards necessary for high-quality work and excellent results.
Partial edentulous segment prosthesis
This type of prosthesis has two points of support, is able to restore several adjacent teeth, both in the anterior and lateral regions. It has a composite or acrylic base, replacing an artificial gum, crowns made of zirconium, ceramics, metal ceramics. Classic two-piece or basal implants can be used as support.
Fully edentulous denture
This type of prosthesis is fixed on 4-10 implants, the implantation operation can take place under the protocol of delayed or instant loading. The approach to the installation process and the selection of materials is quite flexible, so the patient can choose a suitable doctor and all the components of the prosthesis in accordance with his wishes and indications for installation. When choosing a specialist, one should be guided by the presence of a diploma, sufficient experience and the level of professionalism in work. The quality and final appearance directly depend on the budget and work of the doctor.
Installation
Partially removable dentures are recommended for installation if:
- Natural teeth are missing in whole or in part;
- It is necessary to install a denture on the lower or upper jaw;
- Own teeth are destroyed, they need to be removed.
Contraindications
Dentures on implants are contraindicated if there are:
- Diseases of the blood, heart and blood vessels;
- Oncology, tumors, chemotherapy;
- Chronic diseases, exacerbation period;
- Disruption of the respiratory tract;
- Contraindications to anesthetic drugs.
Installation Steps
The standard steps for installing a prosthesis on implants are:
- Diagnostics. The patient undergoes examination and examination, donates blood for analysis, undergoes an X-ray examination;
- Training. The doctor selects the type of implants and prosthesis, materials and method of implantation. The manager draws up a treatment plan taking into account the indications and recommendations of the implantologist;
- Implantation. If there are no contraindications, then the day of the operation is appointed. During the implantation, decayed teeth are removed, the oral cavity is sanitized, dental implants are implanted;
- Prosthetics. Depending on the method of implantation, the doctor chooses the option of prosthetics. In the case of immediate loading implantation, a temporary prosthesis is installed immediately or two days after the operation. With the delayed load protocol, a permanent prosthesis is installed after 4-7 months;
- Replacing the prosthesis. This stage is carried out with an instant load protocol. During it, the adaptive lightweight prosthesis is replaced with a permanent one 3-6 months after implantation.
Advantages and Disadvantages
The advantages of conditionally removable dentures are:
- Reliable fixation in the oral cavity;
- Simple and familiar care of the prosthesis, as for your own teeth;
- The optimum ratio of price and quality;
- The basis of the prosthesis is smaller in comparison with removable prostheses, so there is no discomfort, the addiction is faster;
- Correction and adjustment is required less often, while the reliability of fixation is not lost;
- It is not necessary to perform bone grafting for some types of prosthetics.
Disadvantages:
- the quality of prosthetics directly depends on the budget;
- To install implants, a surgical operation is required;
- During the engraftment period, care must be taken not to damage the implants, not to disturb their stability.