Which orthodontic retainers cause the most plaque accumulation?
Which orthodontic retainers cause the most plaque accumulation?
I have used bonded orthodontic retainers for many years. However, I have always been a little concerned about their potential for causing periodontal harm. This new study provides useful information and identifies a potential issue with retainers that are bonded to all the anterior teeth.
Effects of different orthodontic retention protocols on the periodontal health of mandibular incisors.Rody et al.
Orthodontics and craniofacial research. 19: 4: 198–208 DOI: 10.1111/ocr.12129
A well-known team from Florida wrote this paper. At the moment I am sitting looking out in the semi dark of the mid day winter through the Manchester rain. I would very much like a trip to visit them to discuss their research!
They set out to answer this question;
“Do different retainers cause periodontal harm”?
What did they do?
This was a cross-sectional study. They examined 36 patients who had retainers fitted six months previously. They divided the subjects into three groups of 12 based upon their type of retainer.
- Fixed retainers made of single smooth wire bonded to the lingual surface of the mandibular canines.
- Fixed retainers made of braided wire bonded to the lingual surfaces of all six mandibular anterior teeth.
- These patients wore mandibular removable retainers at night.
They examined the patients six months after they fitted their retainers. The clinicians collected the following information; Pocket depth, gingival recession, bleeding on probing, gingival index and plaque accumulation. They also collected gingival crevicular fluid from the lingual surface of the lower left central incisor. They analysed this and measured for periodontal disease biomarkers.
What did they find?
They found that there were no age or gender difference between the groups. There was also no difference in retention time, pocket depth gingival recession, bleeding on probing and gingival curricular fluid volume. Interestingly, they found that the patients in group 2 (retainer bonded to all teeth) had higher levels of plaque accumulation and gingivitis than the other groups.
When they analysed the gingival curricular fluid they found that there were higher levels of some biomarkers in groups one and two (fixed retainers) than the removable retainer group.
Overall, they concluded that the type of retainer influences the clinical periodontal health of patients wearing orthodontic retainers. This was most marked for retainers bonded to teeth. Nevertheless, this didn’t seem to affect the clinical measures of disease, at least, at this early stage of retention.
Finally, they pointed out that the results of this study agree with other research that did not find a relationship between bonded retainers and severe clinical damage of periodontal tissues.
What did I think?
This study provides us with some useful information. I was reassured to find that the retainers did not cause periodontal disease. It was also good to see that the authors drew attention to some of the deficiencies of their study. These were mostly concerned with the cross-sectional design. This is because this type of study does not take into account any fluctuation in the conditions over time.
I was a little concerned to see that the sample size was rather small and that there was a lack of blinding to the method of treatment. There is also possibility that the patient’s past oral hygiene performance my have influenced the clinician’s choice of retainer.
These issues may lead to some bias within the study. Nevertheless, the findings are also rather logical and I wonder if a larger prospective study would reinforce this information. I certainly feel based on my clinical experience that retainers bonded to all the teeth do result in plaque accumulation. However, this is simple clinical experience and should not outweigh good research!
Emeritus Professor of Orthodontics, University of Manchester, UK.
Hello
The results appear to agree with the conclusions of the parallel randomised controlled trial conducted by Millett et al in 2008 (Millett DT, McDermott P, Field D, Erfida I, Doubleday B, Vandenheuvel A, et al. Dental and periodontal health with bonded or vacuum-formed retainer. IADR Conference Abstract 3168. Toronto, 2008).
Kind regards
Jonathon
Six months is irrelevant. How about six years or 10 years or 15 years?
Surely this is the most relevant comment here.
Another concern about fixed retainers I have is; what happens when they fail. For the patient, the most favourable option is that they can get a prompt repair – before relapse. For the orthodontist, that patient can disrupt your schedule!
I formerly used loads of fixed retainers, now very few indeed. Try to get the patient to invest in a spare(s) in case of loss or breakage. I feel the finest back up retention system is Invisalign Vivera – high quality, strong removable retainers initially supplied in sets of three. With suitable written instructions you will never be troubled with liability for failed retention. [I’m UK based, and our Health Board (Wales) approve of us offering NHS fundedd patients the option of paid supplementation of standard retention with either Vivera or custom made retainer (they all spot how different the cheaper custom made retainers are from each other, even if made by the same technician on the same day)]. To me, a patient who takes up the option of Vivera is a patient unlikely to bother me again – unless they want to invest in a replacements for damaged or lost ones, no new impression required. Also I firmly believe they are likely to enjoy better long term periodontal health than those encumbered by bonded retainers.
Dear Kevin, surely the follow up period is too short to draw valid conclusions?
Another concern I have about fixed retainers is; what happens when they fail? For the patient, the most favourable outcome is that they can get a prompt repair – before relapse. For the orthodontist, that patient will disrupt your practice schedule!
I formerly used loads of fixed retainers, now very few indeed. I try to get the patient to invest in a spare or spares in case of loss or breakage. I feel the finest back up retention system for fixed appliance patients is Invisalign Vivera – high quality, strong removable retainers initially supplied in sets of three. With suitable written instructions you should never be troubled with liability for failed retention. [I’m UK based, and our Health Board (Wales) approve of us offering NHS funded patients the option of paid supplementation of standard retention with either Vivera or a custom made retainer (they all spot how different the cheaper custom made retainers are from each other, even if made by the same technician on the same day)].
To me, a patient who takes up the option of Vivera is a patient unlikely to bother me again – unless they want to invest in a replacements for damaged or lost ones before they are all gone (no new impression required). Also I firmly believe patients with removable retainers are likely to enjoy better long term periodontal health than those encumbered by bonded retainers.
6 month s/p retention is likely inadequate to draw any definitive conclusions about impact of retainer choice on periodontal health. A 2-5 year f/u would be of far greater clinical significance.
Yes, this is true, but I cannot help feeling that if someone has plaque retention problems at six months, they are going to be the same in five years? Or am I being simplistic?
Most likely they will indeed show continued plaque accumulation over the period from 6 months to 5 years. The clinical significance of the accumulated plaque over a time much longer than 6 months would make the study much more relevant, as most of us retain over a period of years and decalcification and periodontal disease is a progressive process.
I have settled on bonded lowers and VFR for uppers. The reason is lost VFR( I tell them after 2 weeks night time only).
I find on retainer checks a fair % have lost their upper VFR (or the dog ate it) and relapse is minimal to none.
I also find my lower 3×3 having few debonds using flowable composite.(I do have some of the same concerns on perio. after years of wear)
I deal with a large Medicaid population and even at a low charge to remake lost VFR most can’t or won’t pay.
Dear Kevin, I did not see any concern regarding the length of time of this study. It was only a six month time frame. Periodontal disease is a progressive disease that doesn’t manifest in six months. As a general dentist, I am seeing patients in their 20’s coming into my office with fixed retainers still in place. Fixed retainers bonded to the lingual of each tooth are a hygiene nightmare. Survey hygienists for their opinion. They are difficult for hygienists to clean; virtually impossible for a patient to maintain over the short term, let alone over a lifetime; which is what they are being advised, “if they want their teeth to stay straight”. I would suggest a study that goes at least 10 years out. I would love to see more discussion among orthodontists about techniques that don’t require lifetime retention. Does the profession have any concerns about the fact that their techniques require lifetime retention? I don’t see orthodontists trying to answer the question as to why this is so? I am saddened by the fact that orthodontists keep doing what they are doing without digging into the root cause of the crowding and the re-crowding. What do you see as the cause of malocclusion?
Thank you, Brian. Very good information.