Impressions in implantology
Today, implant prosthetics are part of our therapeutic arsenal.
If the work of the prosthodontist begins from the pre-implant study by participating in the
determination of a coherent project resulting from the confrontation between anatomical imperatives and prosthetic, functional and aesthetic objectives,
The impression of the implant location is the keystone of the reconstruction.
Impressions in implant-supported prostheses allow
transfer to the laboratory all information relating to the spatial position of the implants and implant abutments between them and also their relationships to adjacent structures
Specificity of the imprint:
Two concepts give the impression in implantology its particularity: difference in support between prosthesis – tooth and prosthesis – implant;
Registration .
In supra-implant prosthesis, the main difficulty is to obtain a passive adaptation
prosthetic elements on the implants. The accuracy of recording the spatial positions of the implants is crucial
Registration :
The implant impression is a three-dimensional marking of the position of the implant and its environment.
This identification requires rigor, because no dimensional deformation is accepted either from taking the impression or from its processing.
A defective impression can cause fracture of the ceramic, screws, or even the implant. It can even lead to loss of osseointegration.
The positive model including the replica of the implant allows the laboratory to choose, adjust and retouch the machined prosthetic parts, as well as the manufacture of the final prosthetic elements.
Structures to be recorded according to the types of prostheses:
- There are two types of prostheses:
- Screwed prosthesis which includes:
-screw-retained prosthesis on implants;
-Prosthesis screwed onto abutment or framework screwed onto implant.
- Prosthesis sealed on abutment screwed onto implant.
Screw-retained prosthesis on implants:
Structures to be registered:
- The impression in implant prosthesis is a situational impression.
- It allows the position to be transmitted to the laboratory either:
- From the implant,
- Or the transgingival abutment.
Preparation of the impression:
This preparation is twofold:
- choice of print type;
- preparation of equipment and materials.
Choice of print type:
The two most commonly used fingerprinting techniques are called direct and indirect. They present radically different concepts, each with advantages and disadvantages.
Materials specific to implant impressions:
Transfers: pop-in, pop-up, clipped, pick-up Analogs:
-Implant analogs
-Analogues of pillars;
– Laboratory screws and screwdrivers; Impression holders: commercial, individual Impression transfer:
- Machined metal part, screws onto the recorded surface:
Implant collar or intermediate abutment, it is specific to the different implant diameters
- It is selected based on the
type of surface to be recorded (implants or abutment)
- The diameter of the implant or
pillar
- The emergence profile of the healing screw
-From the chosen impression technique
Materials:
Impression techniques for prosthetics on implants:
Direct techniques:
clipped or snap-on:
Clips directly onto
the pillars. The specific plastic transfer is placed before the impression. The impression is taken in double mixing with a commercial impression tray.
Imprint processing:
– Disinfection of prints:
- Rinsing
- Disinfectant solutions
- Ultrasound
- Ionization
Casting the impression and making the working model:
It is best to cast the model in the dental office
- When the impression arrives at the prosthetics laboratory, a surface tension reducer must be applied before the plaster is poured.
- The casting is then carried out directly in hard plaster, class IV for its resistance and for its tiny dimensional variation (less than 0.01%).
- First, the technician will place pink silicone that will imitate the gum at the head of the implants.
Limits and indications of the two fingerprint techniques:
Both techniques can be used for the treatment of different types
edentulism in the presence of adequate parallelism of the implants, a normal mouth opening and an anti-rotation system (unitary edentulism)
Indications:
Digital impression of implants:
Introduction :
Intraoral scanners are increasingly used in dental practice, with new and improved devices being introduced at an accelerating pace.
When taking conventional impressions of implants,
The transfer is positioned in the hardened impression material (open impression). This step is omitted when taking a digital impression. Instead of a transfer,
“Scan bodies” are placed in the mouth. They are scannable and reproduce the implant position, like conventional transfer abutments. Implant manufacturer Biomet 3i provides an abutment
Patented scannable healing (exclusively compatible
With 3i implants). This titanium healing abutment contains indentations and depressions on the surface
Sirona has developed scan bodies for all commonly used implants. The TiBase scan body is screwed onto the implant and, like the BellaTek® Encode® abutment, is covered with a plastic cap that can be scanned and provides information about the implant.
Procedure for the CEREC AC and BellaTek® Encode® System
This involves scanning the pillar, the antagonist jaw and the intermaxillary relationship after powdering with the CEREC AC Bluecam camera.
The digital data obtained is transmitted via the internet to the Biomet 3i milling center and is used to design and manufacture custom-made titanium or zirconia abutments, without any model.
Currently, the abutment after completion still needs to be screwed into the mouth and scanned again with the Bluecam CEREC, in order to be able to manufacture the superstructure
definitive with the CEREC unit.
Conclusion :
It is undeniable that digital technologies are becoming increasingly important in the daily work of dentists and offer new possibilities (Lee & Gallucci 2013). These developments already seem irreversible.
How quickly will they establish themselves in dental practice? This is the real question in this field today.
Impressions in implantology
Wisdom teeth can cause pain if they erupt crooked.
Ceramic crowns offer a natural appearance and great strength.
Bleeding gums when brushing may indicate gingivitis.
Short orthodontic treatments quickly correct minor misalignments.
Composite dental fillings are discreet and long-lasting.
Interdental brushes are essential for cleaning narrow spaces.
A vitamin-rich diet strengthens teeth and gums.