Mini- implants are dental implants that are less than 3.0mm in diameter and are in one piece. One of the indications of min-implant is the replacement of a missing lower incisor. The small diameter of the mini – implant is an advantage here due to the lack of space. The lack of mechanical strength of mini-implant is not an issue here as the masticatory load is low in the lower incisor area. However , mini-implant can only be used if there is no need for change in angulation or customization of abutment. This is because mini-implant is in one piece so no customization of abutment is possible.
What are mini dental implants ?
Mini implants are narrower than standard implants , only 2 to 2.5 mm in diameter. Because of its narrow diameter , its limited surface area and mechanical strength means that its clinical application is limited.
The other distinguishing feature of a mini implant is that it is in one piece. The implant abutment comes attached to the implant body and cannot be removed. The lack of interchangeability of implant abutments means that the implant restorative option is vastly limited clinically.
FAQ for mini dental implants
Mini implants are useful for replacement of very small teeth ,for example lower incisors. Mini implants are also useful for retaining dentures for the elderly.
Another indication of mini-implants is for the retention of loose lower dentures. This is especially useful for elderly patients with a lot of medical conditions. It offers a quick solution to very loose lower dentures
Because mini implants are very thin ( 2 to 2.5 mm ), resulting in a lack of strength to withstand the biting forces of a molar, sometimes a dentist will use 2 to 3 mini implants instead. The result is that it is extremely difficult for a patient to keep them clean. Therefore, for molar replacement , a single regular dental implant should suffice.
The x-ray on the left shows 2 mini implants used to replace a single lower molar. The patient had great difficulty cleaning between the 2 mini implants. As a result, the crown and the mini implants had to be removed .
One of the main selling point of mini implant is that its placements are less invasive since most of them are done without opening the gum. However, these are blind surgical procedures and as a result the potential for complications and failures are greatly increased. The x-ray on the left shows a mini dental implant that was placed completely out of the jaw bone . The final result was implant failure with pain and swelling of the gum and lips.
The ability of an implant to take on biting forces depends on its overall surface area. Since mini implants are very narrow , longer mini implants must be used. However, the use of longer mini implants greatly increase the possibility of injuring vital structures.
The x-ray on the left shows a large number of mini implants that were placed in the lower jaw in order to have adequate strength .
But the long mini implants damaged the lower jaw dental nerve during implant installation. As a result, the patient suffered permanent numbness of the lower lip due to the placement of the long mini implants.
The x-ray on the left shows multiple long mini implants placed in both the upper and lower jaw. The long mini implants in the upper jaw pierced the sinus, resulting in implant failure and chronic infections of the sinus. The long mini implants in the lower jaw injured the lower jaw dental nerve resulting in permanent numbness of the lower lip.
The picture on top shows a fixed bridge retained by multiple mini implants. Note the poor aesthetics and poor oral hygiene . Cleaning is virtually impossible .
Mini implants has two distinct limitations.
Mini implants are thin and narrow. Frequently, more mini implants need to be placed in order to have strength. The picture on the left shows 4 mini implants which were installed to replace 4 lower incisors. Because too many mini implants were placed too close to one another, the jaw bone was damaged . As a result, all the 4 mini implants failed and they had to be removed. If regular implants were used instead , only 2 regular implants would be required to support a 4-unit fixed bridge. By using 2 regular implants, the procedure is simplified and complications can be avoided.