Primary stability decides the success of implants! Getting to the basics, primary stability is the measure of initial bonding between the implant and the bone. As the life of implant is decided by the primary stability, we can confidently say primary stability is the password of the implant integration account. Good primary stability means the implant can load quickly and to the maximum.
Here are three factors which influence the primary stability:
Synchrony in the above factors ensures maximum stability.
- The quality and quantity of surrounding bone
Mandible, especially anterior mandible has more and better bone structure than the maxilla. Compact to trabecular bone ratio, which is the deciding factor for stability, is higher in the anterior mandible. Thus, anterior mandibular implants have a higher success rate than the maxillary implants.
- The design of implant
The implant design plays a good role in primary stability. The following modifications increase the primary stability:
- Tapering implants with a wider taper
- Texturing the surface of implants
- Etching the surface of implants:
Acid etching helps to reduce the failure rate of implants by five times. SLActive (sandblasted, large-grit/acid-etched active surface) is a chemically modified implant surface. The implant is conditioned in nitrogen and immediately preserved in an isotonic saline solution. This process helps to maintain its high surface activity and chemical purity. The hydrophilic properties of SLActive implants increase early cellular activity and bone apposition. Thus, there is faster osseointegration.
- The type of surgery
The following techniques increase the primary stability:
- Slanting the implant at an angle of 60 or 120
- Increasing the insertion torque of implant:
Underpreparing the bone/ drilling a hole of smaller diameter than what is the need for the implant is advisable. Then, it needs more pressure to place the implant right and this pressure is known as torque. This technique is more useful when there is low bone-density, as this technique increases the density of bone.
However, dental implants by Bicon are an exception. Bicon is popular for successful implants. They do not recommend under-preparation of bone for inserting implants.
- Anchoring the implant to at least two cortices is beneficial when there is low bone density.
- Condensing the surrounding bones via condensers helps to increase the density of surrounding bones.
In addition, maintaining a low implant micro-movement in the early healing periods helps the surrounding bone grow over the implant.
Good primary stability ensures the deposition of bone in between the implant and the surrounding bone and prevents the deposition of other connective tissues. Assessing the initial stability at regular periods helps successful osseointegration. PT/ Periotest and RFA/ Resonance Frequency Analysis measurement using Osstell device are the two types of tests which measure the primary stability. PT gauges the temporal tip during repetitive percussions, and RFA has a graphic display panel which shows the ISQ/ Implant Stability Quotient values.