By: Dr. Pierre Pellan
Has it ever happened to you…a patient is scheduled to get her or his braces off, occupying a good 2 hours of chair time? Then, while you were just about to start a new consultation, your auxiliary is gently waving her hand to you through the door window and wants to talk to you: this patient noticed that the two front teeth slightly moved out of alignment in the past few days, and is wondering if it might correct itself after braces will be off…of course, that is not going to happen...
I saw that more than once. It has happened to many clinicians doing orthodontics. For the past years I truly enjoyed visiting different orthodontic offices in order to get as many tips and tricks as possible. On one occasion I couldn’t help but notice that some of the patients who were near the end of their treatment already had their fixed lingual retainers in. Besides thinking to myself ‘these teeth aren’t allowed to move anymore’, I also thought ‘these anterior teeth probably have crossed the finish line already and are waiting for the rest of the occlusion to settle before the big day of removal’. I thought I should apply this protocol in my own practice.
Once I am perfectly happy with either upper or lower anterior teeth position, I will take a partial impression of these front teeth using alginate. The patient is then scheduled to be back as soon as possible for bonding of the lingual retainer (either on the same day, 1 or 2 days after impression). This will allow me to pour a small stone model that will guide in the making of the lingual wire.
A small piece of 0.018 TMA wire is closely adjusted from one cuspid to the other, and then held in place with a drop of flowable composite. I stopped using multistrand wires since I had 2 patients who came back many years after their treatment had finished with a single tooth that rotated way out of proper torque, probably because the wire started rolling back locally after breakage (fig. 1)
Since it is mandatory that this wire be passive when bonded to the teeth, I don’t use dental floss to hold it in place. That would increase the chances of incorporating a force in the wire that could move the teeth out of ideal position. This is why a putty key is prepared that includes central incisors and a bit of the laterals too. This key will allow correct intraoral placement of the wire without generating any unwanted force (fig. 2).
Clinically, I use a sandblaster that is connected directly on my dental unit, to remove proteins that stay on the lingual surfaces of the teeth. This will insure that nothing comes between the etching agent and the enamel (Fig 3 and 4). Fifteen seconds of etching is enough to get a frosty appearance of the enamel, and a light coat of sealant is then applied (Assure (Reliance)) (fig. 5).
The composite I use to bond the wire on every single anterior tooth is Transbond LR from 3M. It has just the right texture allowing the clinician or auxiliary to shape it to the desired end result (Fig. 6). I make sure the composite entirely covers the wire. I very rarely had patients complaining about the thickness of these ‘pearls’, so I try to err on the side of applying more than less. Just make sure the curing light comes as close as 1 mm to the surface for a near perfect long-term result (Fig. 7).
If the gums are somehow puffy, I will wait 2 weeks after debonding before taking new impressions for clear retainers (0.030 Essix A+). In my office, we won’t charge if these need to be remade for a period of 12 months.
Patients will then come back for a short visit of stability and retention evaluation 3 months after the end of treatment, then 9 months later, and then 12 months later (24 months after debonding). They are then advised that fees will apply should the retention wires need a touch-up. Even the best things don’t last forever…