Although the success rate of ORLUS orthodontic mini-implants may have increased, loosening of the orthodontic implant may also occur; this situation is very embarrassing. Epidemiological studies have pointed towards the following: most failures arise from the bone-implant interface and most failures occur shortly after implantation. The failures of the bone-implant interface come from inadequate primary stability, excessive surgical trauma, and unfavorable healing conditions. During treatment, impact stress or irritation from surroundings may also cause loosening.
For using orthodontic implants that have an improved structure for enhanced stability, the use of a standardized procedure with full understanding of the mechanism can increase the rate of success (figure 1, 2). Additionally, the operator must also focus on the procedure.
The patient must be informed of the possibility of loosening of implants and the possibility of re-implantation before the surgical procedure. Pre-medication for pain control is very important, and is also effective in decreasing anxiety in the event that re-implantation is necessary after initial failure.
When a tight fit is not felt during the final stage of the insertion procedure, this indicates that sufficient primary stability can not be obtained and that the implant will probably fail. This is caused by poor bone quality, wobbling, or unintentional excessive surgical trauma during insertion. If this situation occurs, the following may be helpful; first, the presence of poor bone quality or poor primary stability should be noted to the patient or parents of the patient because the patient may be surprised at unexpected implant loss. Second, changes to orthodontic implants with wider diameter and deeper insertion should be considered. Third, additional insertion at another site should be considered. A NiTi coil spring with a light force of no more than 100 gm is also recommended. After confirmation of stability, orthodontic force may be increased.
If mobility of an implant is detected at the follow-up appointment, the implant should be considered as a failure. However, in case of slight mobility, the following form of management can be considered: deeper insertion under infiltration anesthesia will increase mechanical stabilization due to the unique design of the new type of implant. This procedure should only be performed after the patient or parents of the patient have been notified. Use of a NiTi coil spring is also recommended. It should be noted that when insertion is made deeper, the chance of burial by soft tissue increases.
The success rates in individuals younger than 15 years of age are relatively low because the bone quality and quantity is relatively poor in young teenage. Therefore, the protocols for younger patients should be followed(Vol.2 Site selection, p2).