Which orthodontic appliance is the best for oral hygiene? A randomized clinical trial

Orthodontic treatment is an appliance-specific process, where several mechanical components unite into one efficient device to bring about tooth movements. While they may be widely celebrated for their ability to correct malocclusion, these orthodontic appliances – traditional or contemporary – are not very well known for providing top-notch oral hygiene.

In fact, by virtue of the close proximity of the devices to the oral structures over a prolonged period of time, they can represent an important personal challenge. Poor oral hygiene coupled with orthodontic treatment can cause adverse side effects primarily enamel demineralization that causes white spots on areas where brackets (in case of braces) or attachments (in case of aligners) are attached to the teeth. Caries, gingival inflammation, halitosis, periodontitis, and ulcers can also be common drawbacks of inadequate oral hygiene during orthodontic treatment.

The placement of orthodontic appliances can not only promote an inordinate accumulation of biofilm around the frames but also increases the level of cariogenic bacteria in the mouth. This festering pool of bacteria can further worsen the oral health of the patient and negatively affect their quality of life.

But which of the orthodontic devices proves to be better for your oral hygiene? Do the metal structures of traditional braces help harbour fewer bacteria? Or, do the clear trays of aligners make room for more bacteria activity? Let’s find out.

This study was conducted by a team from Ohio, Connecticut, and Australia. It was published in the American Journal of Orthodontics and Dentofacial Orthopedics.

Which orthodontic appliance is best for oral hygiene? A randomized clinical trial.

Chhibber A(1), Agarwal S(2), Yadav S(3), Kuo CL(4), Upadhyay M(5).

 Am J Orthod Dentofacial Orthop. 2018 Feb;153(2):175-183. doi:

10.1016/j.ajodo.2017.10.009.

 

Author information:

• Private practice, Norwalk, Ohio.
• Department of Orthodontics, Melbourne Dental School, University of Melbourne, Melbourne, Australia.
• Division of Orthodontics, Department of Craniofacial Sciences, University of Connecticut Health, Farmington, Conn.
• Department of Community Medicine and Health Care, Connecticut Institute for Clinical and Translational Science, University of Connecticut Health, Farmington, Conn.
• Division of Orthodontics, Department of Craniofacial Sciences, University of Connecticut Health, Farmington, Conn. Electronic address: maupadhyay@uchc.edu.

 

What they asked

Through this study, they aimed:

“To compare the effects of clear aligners, self-ligated brackets, and elastomeric-ligated brackets on patients’ oral hygiene during active orthodontic treatment.”

 

What they did

They conducted this 3-arm parallel-group prospective randomized clinical trial to compare the long-term and short-term effects of three types of orthodontic devices on patient’s hygiene:

1. Clear aligners
2. Self-ligated brackets
3. Conventional (elastomeric-ligated) brackets

The study was single-blinded with an allocation ratio of 1:1:1.

71 participants above the age of 12 (41 boys, 30 girls; mean age = 15.6 years) at the commencement of treatment, were selected.  Each had an anterior crowding or spacing of less than 5 mm with adequate overjet and overbite.

The participants were randomly allocated to one of the groups through a computer-generated randomization schedule:

1. Clear Aligners (CLA) (Align Technology, San Jose, Calif) (n = 27)
2. Pre-adjusted edgewise fixed appliance with self-ligated brackets (SLB) (Carriere, Carlsbad, Calif (n = 22), or
3. Pre-adjusted edgewise fixed appliance with elastomeric ligated brackets (ELB) (Ortho Organizers Inc., Carlsbad, CA) (n = 22).

The participants were requested to refrain from eating, drinking, or brushing one hour before the sampling appointments. They were also given strict oral hygiene instructions throughout the treatment.

The primary outcome for each participant was plaque index (PI). Secondary outcomes included gingival Index (GI) and periodontal bleeding index (PBI). Periodontal measurements were recorded specifically for the maxillary second premolar on three occasions, (i) before treatment – T0, (ii) after 9 months of treatment – T1, and (iii) after 18 months of treatment – T2.

The patients and clinical investigators in each group could not be blinded to the intervention. It was only done for outcome assessment and for the statistician. 10 participants did not receive the allocated intervention for various reasons.

 

N

They included this table to demonstrate their findings for plaque index:

Plaque Index (PI)

 

		Self-ligating brackets (SLB)	Clear aligners (CLA)	Elastomeric-ligated brackets (ELA)
Mean ± SD	T0	0.65 ± 0.49	0.50 ± 0.51	0.70 ± 0.73
	T1	1.38 ± 0.72	0.83 ± 0.48	1.32 ± 0.67
	T2	1.07 ± 0.59	0.92 ± 0.58	1.32 ± 0.67

 

The odds ratio (OR) for plaque index (0 or ≥1) comparing SLB or CLA to ELB was not significant.

The odds ratio for SLB vs ELB were found to be:

• T0 – 1.54 (95% CI, 0.39-6.27)
• T1 – 0.88 (95% CI, 0.03-24.69)
• T2 – 0.83 (95% CI, 0.02-27.70)

The odds ratio for CLA vs ELB were found to be:

• T0 – 1.07 (95% CI, 0.30-3.88)
• T1 – 0.24 (95% CI, 0.01-1.98)
• T2 – 0.17 (95% CI, 0.01-1.71)

However, the odds ratios comparing CLA with ELB for gingival index  (OR = 0.14; P = 0.015) and periodontal bleeding index(OR = 0.10; P = 0.012) were statistically significant at T1.

 

What we can conclude

Finally, they concluded that there was no significant evidence to prove that any of the products used in this study caused any safety hazards to the soft ot hard tissues. They also found no proof of any significant difference in the oral hygiene levels among clear aligners, self-ligated brackets, and conventional (elastomeric-ligated) brackets after 18 months of active orthodontic treatment.