We sent out a survey asking doctors for their questions about retainers & finishing cases.
In this week's tip, we've consulted with our Clinical Advisor, Dr. Ken Fischer, to get answers to some of your questions.
General questions about retainers
Can you offer guidance on the parameters for requesting additional aligners, chain, elastics, or fixed, full, or segmental braces?
Whenever treatment is not progressing as the doctor prescribed or intended, and after proper analysis discloses the reason it isn't, additional aligners or any of the other appropriate treatment auxiliaries may be called upon to re-orient treatment in the proper direction. The choice of which auxiliary to utilize is determined by the doctor according to what he/she feels would work best for the patient based upon the doctor's training and experience.
Treatment should be closely monitored at each appointment. If it seems that additional aligners are needed or treatment may need to be revised, you can use the treatment setupas a guide to help you diagnose what may have gone off track. For example, by comparing where the teeth are now to where they should be according to the treatment setup (based on the step the patient has advanced to), you will likely find where some of the planned tooth movements have not occurred. Whenever planned tooth movements have not occurred, it boils down to either not enough space for the tooth to move into or not enough pressure in the direction needed to move the tooth.
If you find that the teeth have incomplete movements (not extruded or rotated, etc.), check out our Help Center for some solutions based on your diagnosis of the issue:
Are the final retainers made differently than the aligners so they can sustain over time? For example, some patients say that their aligners feel more loose/stretch close to their 2nd week end mark, whereas the retainers are to be worn indefinitely after treatment. So, will this happen to the retainers as well?
ClearCorrect makes retainers from the same high-quality thermoplastic as its aligners. Ultimately, all thermoplastic materials will loosen with time. Occlusal forces, care by the patient, and the material chosen for the aligner or retainer can all affect how long they last. ClearCorrect provides the best material it can to sustain an optimum fit over time, but all thermoformed appliances will need to be replaced eventually. We recommend you switch out clear retainers for a new pair every 6 months.
I am new to clear aligners and am curious if the retainers fit similar to the active aligners.
Yes, just like the aligners for active tooth movement, retainers should initially have a snug fit that will eventually loosen over time.
Can a patient use the last aligner as a retainer?
Yes, as long as the aligner remains in good condition.
Questions about retainer wear
When is the best time to request retainers?
The best time to order retainers is as soon as the doctor's objectives and patient's preferences are resolved to the satisfaction of both.
How long do patients wear retainers? At least 22 hours per day? At what point do they go to wearing only at night? How long after the completion of a case should they wear the aligners?
The term a patient will be required to wear their retainers is determined according to the retention protocol established by the doctor. When making this decision the doctor weighs the type of treatment provided, difficult movements accomplished, patient compliance, along with other factors. For more information on retainers & retention see the article on this topicin our Help Center.
How long should each retainer last with 22/7 wear?
How long a retainer survives is mostly dependent upon how the patient cares for their retainer, how often and hard they chew on the material, how well they clean it, how carefully they insert and remove it, etc. As mentioned earlier, we advise ordering a new retainer for your patient after about 6 months of wear.
Instructions for proper wear and care for ClearCorrect aligners can be found here.
Questions about fixed retainers
When would the use of permanent retainers be acknowledged?
Fixed retainers are effective at retaining teeth that have been significantly rotated during treatment and when the patient adamantly demands one. You may also want to consider fixed retainers for patients with the tongue thrust habit or for patients that are more inclined to relapse due to failure to wear their retainers.
Some of my patients request a lower fixed retainer. Do you provide this service? If you don't what is your recommendation to give this service to my patient?
Some doctors insert bonded, fixed lingual retainers as an in-office procedure. Some labs will fabricate the wire for you, but it still needs to be bonded in the office by the doctor or staff. We do not provide the material for this option at this time.
Is it necessary to use a fixed lingual retainer if the patient uses removable retainers?
No, not at all.
What should be used for a fixed lingual retainer?
The decision of what type of wire to use for the fixed retainer is made by the doctor based on their preference and experience. Some doctors prefer a single round wire, such as a .032, that is contoured to precisely fit the lingual of the aligned anterior teeth and then bonded on the ends directly to the cuspids. Some doctors use a "braided" or "twisted" wire applied to the lingual of selected teeth, but these wires must be bonded to each tooth.
I have difficulty with upper fixed retainers being placed in the occlusion and then needing to deal with no posterior contact. Do you have any suggestions?
Upper fixed retainers should not be used if they interfere with the bite and prevent posterior contact.
I have difficulty with patients who have midline diastema (spacing) between #8 & #9. I like to place a fixed lingual wire retainer 1x1 on 8-9. If I do this, then the final retainers from you do not fit. So, I end up making a retainer myself and do not use the one provided. Do you see any way around this?
As long as the patient wears the provided ClearCorrect retainer full-time, the diastema should not re-open. When the patient begins part-time wear, i.e., bedtime only, perhaps just placing a small dollop of adhesive between 8-9 will still allow the retainer to fit.
Questions about finishing cases
What are the criteria for a good finish?
The best evaluation of a "good finish" is when all of the doctor's and patient's goals or treatment expectations are met. There isn't another definition for a "good finish" that will apply to all treatment and all cases.
Sometimes near the end of cases, within the last one or two aligners, I notice a little lack of tracking. Maybe it is insufficient IPR or lack of patient compliance. I'm wondering if you have any other suggestions of what this could be.
Lack of tracking can certainly be attributed to one or both of the 2 factors mentioned. The first thing to do is to have the patient wear the last aligners an extra week or 2. If they follow their instructions properly, a good fit should be re-established. If not, you have a few options:
- You can request a reproduction of the last aligners (a new set will snap on again and may complete these last movements)
- Check for tight contacts, address any found and extend the wear of the last aligners or request a reproduction of them
- If slight rotations are still needed, you can add some dimples where applicable to the last step, with either the current aligner or a reproduction
- At the outset of the case, you can request either overcorrection or a digital power chain which may help to prevent against needing a revision at the end of the case. (However, be advised that even when these adjustments are requested at the beginning of treatment, poor patient compliance and/or difficult movements may still result in the need for a revision.)
- And, if you prefer, you can also do a revision
It seems like there will most probably be some open contacts based on the occlusion. How much correction is expected after the case is complete?
First, determine if the open contacts are in excess to what was approved in the original treatment setup. What you're trying to determine is: do the open contacts match the oclcusion that was approved in the treatment setup or are they there due to incomplete tracking during the treatment? Minor open contacts in the occlusion will most likely "settle" into contact if given the freedom to do so. This will require a Hawley-type retainer. If the open contacts are significant, a revision requesting a digital power chain can always be submitted to "tidy" everything up.
What do I do if retainers are ordered, the case is closed and then the patient decides they want a revision too late?
Re-open the case, re-take impression/scans and submit a revision to comply with the patient's request. If there is an additional fee imposed by ClearCorrect, the doctor will need to decide whether or not to charge the patient.
How can I avoid revisions at the end of treatment by planning before or doing revisions mid-treatment?
Doing mid-treatment revisions does not always prevent the need for a revision at the end of treatment. Patient non-compliance can require an additional revision prior to delivering the retainers. Difficult tooth movements, such as extreme rotations, require careful monitoring and attention throughout the treatment in order to avoid end-of-treatment revisions. The best way to avoid end-of-treatment revisions is to require optimum compliance from the patient.
Another option is to request overcorrection or a digital power chain when first submitting the case.
I have difficulty getting teeth that were planned to erupt/extrude to do so.
Extrusion of fully erupted teeth is one of the more difficult tooth movements to successfully accomplish with clear aligners and requires the use of a horizontal engager. Whenever a tooth is expected to erupt or be extruded, always ensure that there is plenty of space to allow the eruption or extrusion to occur. For further help on extrusions, check our our article on Extruding with Auxiliaries.
I have difficulty closing open bites. Even with engagers, I am having difficulty closing an open bite on a lateral incisor. There is sufficient space (interproximal contacts are light between the lateral and its opposing dentition). Will it be necessary to remove the current engagers, re-scan and re-treat? Or, can I leave the engagers on, re-scan and re-treat? Or, should I give up and tell the patient I have done everything possible to close the space?
First thing to make sure of is that there is no contact between the lateral and adjacent teeth. You can re-scan/re-impress, but you must remove the engager prior to re-scanning or re-impressing. Consider using the buttons and elastic technique as described in the article on this topic in the Help Center. This is an effective auxiliary technique for coaxing a stubborn lateral into place. For more information on open bites, check out the following articles:
I have difficulty sometimes with small rotations to finish a case which gets me stuck. Is there anything you can recommend for this circumstance?
The most common reason those lower incisors are the last to line up is usually because there is still a shortage of space for it to turn into. If this is the case, perform IPR, adding some dimples or submit for a revision. Alternatively, consider using a Hawley-type retainer or limited fixed braces to turn the tooth.
Finishing rotations is difficult. I asses if a little more IPR is needed, but it is a difficult/unpredictable movement for clear aligners I think, especially well-rooted teeth like canines. Would your fabricating internal "positives" to push on the rotated teeth line angles, help more than the engagers alone?
ClearCorrect does provide various vectors of pressure on rotated teeth to enhance effective rotation, however, the use of engagers is the best method for effecting rotations.
Tips & tricks
Some of our providers offered a few tips & tricks on the topic of retainers and finishing cases. Nothing here should be taken as official advice or recommendation from ClearCorrect or its employees. It's up to you to use your professional judgment on what is best for you and your patients.
- "I tell everyone that 'teeth have memory' and retainers are for life."
- "Make the patient aware before they start treatment that they will be wearing them almost 24/7 for a year following completion."
- "Use a fixed lingual wire with rotated or initially spaced teeth when possible before the retainers are made by your lab."
- "I have found that scanning is superior to impressions in initial fit."
- "I recommend retainer wear only while the patient is at home so that it doesn't get lost. At first, I suggest wearing it only while sleeping. If the retainer is tight, that means the patient needs to wear it more and then I suggest wearing it from after dinner until morning."
- "I always tell the patient that at the end we will do some aesthetic contouring to get edges even, etc. It gives me the ability to smooth incisal edges and often round a line angle on any teeth that may have not fully rotated."
- "I recommend thermoforming."
A big thank you to all the providers who answered our survey!
Check out our Help Center for more helpful information on clear aligner treatment.
Until next time...