A randomized, 3-month, parallel-group clinical trial to compare the efficacy of electric 3-dimensional toothbrushes vs manual toothbrushes in maintaining oral health in patients with fixed orthodontic appliances


The aim of this single-blinded, parallel-group, randomized clinical trial was to compare the efficacy of electric 3-dimensional (3D) toothbrushes and manual toothbrushes in removing plaque and reducing gingival inflammation in orthodontic patients.


Eighty adolescents with fixed orthodontic appliances in both arches were randomized at a 1:1 ratio, with an equal number of both sexes, in this examiner blinded, parallel clinical trial. Eligibility criteria included subjects aged between 12 and 16 years, good general health, nonextraction orthodontic treatment, and plaque-induced gingivitis, excluding patients with active caries or periodontitis, tooth agenesis, syndromes, disabilities, and craniofacial deformities, ≥2 cervical and/or proximal fillings, dental prostheses or dental implants, and subjects smoking or using antibiotics or medication predisposing to gingival enlargement. Patients were assigned to use either an electric 3D orthodontic toothbrush (Oral-B Pro-1000 with Oral-B Ortho head; Procter & Gamble, Cincinnati, Ohio) or a manual toothbrush (Oral-B Orthodontic brush; Procter & Gamble) and instructed to brush twice daily for 2 minutes. The main outcomes were: (1) plaque removal, assessed with the Modified Silness and Löe plaque index and the Modified Full Mouth Plaque Score, and (2) gingival inflammation reduction, assessed with the Modified Silness and Löe Gingival Index and the Modified Simplified Gingival Index. Measurements were taken at baseline, 1, 2, and 3 months. Randomization was achieved with 2 random sequences, one for each brush, written and sealed in opaque numbered envelopes. Blinding was possible for outcome assessment only.


Considerable variability was observed among patients in the values of all dependent variables. There was no difference between interventions over time for any of the outcomes, and the main effects for treatment and time were also not statistically significant. For Modified Silness and Löe plaque index, the interaction was 0.001 (95% confidence interval, −0.011 to 0.013; P = 0.89).


No difference in plaque removal efficacy and gingival inflammation reduction was found between the electric 3D and manual toothbrushes in adolescents with fixed orthodontic appliances. Therefore, orthodontists should focus on enhancing their patients’ dental awareness and oral hygiene, along with professional prophylaxis and other oral hygiene aids, independently of the brush used.


This trial was registered at ClinicalTrials.gov (Identifier: NCT02699931).


The protocol was not published before trial commencement.


Electric and manual toothbrushes and toothpastes for all participants were provided by Procter & Gamble (Oral-B). Miscellaneous costs were covered by the participating departments.


  • We tested an electric 3-dimensional toothbrush vs a manual brush in orthodontic patients.

  • Plaque and gingivitis indexes were the main outcomes for 3 months.

  • Interpatient differences accounted for most of the variation of outcomes.

  • Electric brushes were not superior in maintaining orthodontic patients’ oral health.

Patients in orthodontic treatment with fixed appliances need meticulous oral hygiene to maintain dental health, as orthodontic appliances promote food retention and shelter dental plaque from the debriding action of brushing. Ineffective brushing leads to undisturbed supragingival plaque build-up, which triggers gingival inflammation, causing increased gingival sulcus depth, and potentially, caries and enamel white spots. , Furthermore, the subgingival environment associated with the presence of orthodontic brackets experiences microbial changes that include a shift toward gram-negative organisms and a reduction of gram-positive cocci. , Antimicrobial agents and fluoride products are helpful, but cannot substitute for the mechanical removal of plaque, still considered the most important means of oral hygiene during orthodontic treatment. ,

Many randomized clinical trials have assessed the efficacy of various types of toothbrushes in orthodontic patients regarding 2 main areas of interest: plaque removal and gingival inflammation. Several studies have concluded that electric toothbrushes offer statistically significant benefits over manual brushes in at least one of these areas, others have found no difference between the 2 brush types, and another concluded that manual brushes are better in at least one area. In general, electric toothbrushes seem to perform equally to manual brushes regarding plaque and gingival indexes, but they may perform better in reducing the incidence of bleeding on probing and interdental bleeding. , Recent systematic reviews and meta-analyses have investigated whether manual or electric toothbrushes were more effective in achieving good oral health in orthodontic patients. Kaklamanos and Kalfas concluded that there was not enough evidence to support the superiority of electric toothbrushes in controlling gingivitis in patients under fixed orthodontic appliance therapy. D’Costa et al concluded that although electric toothbrushes probably provide some improvement in oral health, this is not strong enough to justify electric toothbrushes’ higher cost. Al Makhmari et al concluded that electric toothbrushes might better promote gingival health, but without demonstrating clear superiority over the manual brushes. ElShehaby et al, in the most recent meta-analysis, found no difference between manual and powered toothbrushes in plaque or gingival indexes at 4-week and 8-week follow-up.

Electric toothbrushes are continually being improved by the manufacturers, potentially leading to a substantial clinical effect. Electric toothbrushes incorporating 3-dimensional (3D) movement have not been sufficiently tested. Therefore, a randomized clinical trial was needed to evaluate whether 3D electric orthodontic toothbrushes are more effective in reducing plaque and gingival inflammation in orthodontic patients than manual orthodontic brushes.

Specific objectives or hypotheses

Our research hypothesis was that the 3D electric toothbrush is superior to the manual toothbrush in removing plaque and reducing gingival inflammation in patients with fixed orthodontic appliances.


The present study aimed to compare toothbrush efficacy in plaque removal and gingival inflammation reduction between an electric 3D toothbrush and a manual toothbrush in adolescents undergoing orthodontic treatment with fixed orthodontic appliances.

Material and methods

Trial design and changes after trial commencement

This trial was designed as a randomized, controlled, investigator blinded, superiority trial, with 2 parallel groups and a 1:1 allocation ratio. An equal number of men and women were allocated to each group.

An interim analysis was planned when half of the subjects completed the trial, but this was not carried out. In addition, because of slow patient flow and to complete the study within the planned period, we relaxed the lower age limit and included 7 patients aged below 12 years. No other changes to the original protocol occurred.

Participants, eligibility criteria, and setting

Patients undergoing orthodontic treatment with fixed appliances, treated by residents at the Department of Orthodontics, School of Dentistry, National and Kapodistrian University of Athens, were recruited. The duration of the study was 3 months. The following selection criteria were applied: fixed labial appliances on the maxillary and mandibular arch, twin metal brackets of the same type on all teeth from the central incisor to the second premolar, bands on the first molars, placed at least 2 months before enrollment into the study, ages between 12-16 years, good general health, nonextraction orthodontic treatment, and moderate plaque-induced gingivitis. To ensure that improvement in gingival health could be demonstrated, patients were included if they had gingival bleeding on at least 30% of the sites examined.

Subjects with active caries, periodontitis, tooth agenesis (excluding third molars), syndromes and craniofacial deformities, current use of an electric toothbrush, >2 cervical and/or proximal fillings, dental prostheses or dental implants, disabilities that might affect toothbrushing skills, perioral or intraoral piercing, cardiac or other medical conditions that require antibiotic prophylaxis for dental treatment, as well as subjects smoking or using other tobacco products, taking antibiotics during the last 2 months or medication that may result in gingival enlargement, and participating in other trials were excluded. , , ,


The brushes compared in this trial were a 3D electric orthodontic toothbrush (Oral-B Pro-1000 with Oral-B Ortho head; Procter & Gamble, Cincinnati, Ohio) and a manual toothbrush with an orthodontic head (Oral-B Orthodontic brush; Procter & Gamble). The Oral-B Pro-1000 exhibits a combination of a rotation oscillation movement, in which the brush head rotates in 1 direction and backward, and a pulsating movement, in which the brush head moves toward and away from the teeth. The pulsating movement stops whenever the pressure exceeds a predefined threshold. The brush incorporates a timer that buzzes every 30 seconds, signaling the recommended time to switch brushing from 1 quadrant to the next. The Oral-B Orthodontic manual brush has a V-shaped groove along the long axis of the head. The toothbrushes, both electric and manual, have not been reported to cause harm, disturbances, or allergic reactions to patients.

Eligible patients were randomly allocated at a 1:1 ratio between group A (electric toothbrush) and group B (manual toothbrush). All brushes, along with toothpaste, were delivered by the same investigator, and patients were instructed on how to brush at the commencement of the study. Participants were instructed to brush twice daily for 2 minutes, once after lunch and once before night sleep, and asked not to use other toothbrushes and toothpaste, not to use whitening products, and to inform us if they visited their dentist for treatment, including cleaning, periodontal treatment, or topical fluoridation. Two-minute timers were provided to group B patients; the electric toothbrush incorporates a 30-second timer. Treating clinicians were asked to refrain from commenting on the oral hygiene of the patient, from providing oral hygiene instructions, and from performing tooth cleaning.


The primary outcomes were plaque accumulation and gingival inflammation. The indexes for plaque accumulation were the Modified Silness and Löe plaque index (PI-M) , ( Table I ) and the Modified Full Mouth Plaque Score (FMPS-M). Indices used for gingival inflammation were the Modified Gingival Index (GI-M) ( Table II ), and the Modified Simplified Gingival Index (GIS-M). Modification of indexes is recommended for patients with fixed orthodontic appliances because it acknowledges the effects of orthodontic appliances on plaque distribution and results in much greater categorical discrimination. , , , Only labial surfaces of all bonded teeth were measured and scored for all primary outcome measures. Banded molars were measured and scored only for GI-M and GIS-M. For details of the indexes, see Supplementary data .

Table I
Description of the PI-M index
0 No plaque
1 A film of plaque adhering to the free gingival margin and adjacent area of the tooth. The plaque may be seen in situ only after the application of disclosing solution or by using the probe on the tooth surface
2 Moderate accumulation of soft deposits within the gingival pocket, or the tooth and gingival margin, which can be seen with the naked eye
3 The abundance of soft matter within the gingival pocket and/or on the tooth and gingival margin

Table II
Description of the GI-M index
0 Normal gingival
1 Mild inflammation, slight change in color and subtle change in texture, no bleeding on probing the gingival crest
2 Moderate inflammation, moderate glazing, redness, edema, bleeding on probing the gingival crest
3 Severe inflammation, marked redness and edema/enlargement, ulceration, bleeding on probing the gingival crest and/or spontaneously

The primary outcomes were assessed at monthly intervals (baseline, 1, 2, and 3 months) by an investigator blinded to the assigned group and calibrated by a periodontist at the start of the trial. Patients were examined before the orthodontic appointment, and all indexes were recorded in study-specific forms.

Sample size calculation

We based our sample size calculation on the customary 5% and 80% alpha and power levels to detect a 20% difference in plaque scores between the 2 groups. Average and standard deviation values were obtained from previous research. Assuming an equal number of subjects in each group, an average plaque index of 1.25 and standard deviation of 0.35 resulted in 32 subjects per group. We decided on 40 subjects to cover potential drop-outs. This number covers the recommendation of the American Dental Association, Council on Scientific Affairs for at least 30 subjects per group.

Interim analyses and stopping guidelines

No interim analysis was conducted; all data were analyzed after the study was completed.


Stratified randomization was used, and patients were allocated at a 1:1 ratio between group A (electric toothbrush) and group B (manual toothbrush) for each sex separately. Two random sequences were obtained from www.random.org (List Randomizer service), 1 for the male group and 1 for the female group. Each sequence was a random ordering of a list of 20 electric and 20 manual, and the sequence values were written on standard-sized pieces of paper and sealed in opaque numbered envelopes sequentially numbered from F1-F40 (female group) and M1-M40 (male group) by a person not involved in the project. All patients who gave consent for participation and fulfilled the inclusion criteria were allocated by the investigator for an initial interview, recruitment, and clinical measurements. Allocation envelopes were kept away from the investigators, locked and accessible only to a secretarial staff member not involved in the project. On new patient recruitment, the next numbered envelope from the male or female pack was retrieved, and the name of the patient was written on the envelope before opening.


Clinical measurements of plaque accumulation and gingival inflammation were conducted by an assessor blinded to treatment allocation. Because of the nature of the intervention, neither the participants nor the investigator offering the brushes could be blinded to allocation.

Statistical analysis

Descriptive statistics were computed for all variables. Linear mixed-effects models were fitted to each of the dependent variables of the primary outcomes (PI-M, FMPS-M, GI-M, and GIS-M) using a random coefficients model (intercept and slope), time from baseline as a covariate, and an unstructured covariance type. All main effects (time, age, sex, and brush) and all 2-way interactions were entered into a full model, and each factor was sequentially removed if P >0.05. We used the maximum likelihood estimation method and compared nested models by 2-Log Likelihood, Akaike’s Information Criterion (AIC), and Schwarz’s Bayesian Information Criterion. Bootstrapping (10,000 samples) was applied to the final model to compute estimates of the fixed effects and covariance parameters. The residuals were evaluated by visual inspection of Q-Q plots. SPSS Statistics for Windows (version 25.0; IBM, Armonk, NY) was used for the analysis. Graphs were prepared with Microsoft Excel (Microsoft, Redmond, Wash).


Participant flow

Recruitment was from April 2016 to February 2019. Ninety-four patients were screened for eligibility ( Fig 1 ). Of these, 10 did not meet the inclusion criteria (extraction treatment, close to the end of treatment), and 4 refused to participate. Recruitment ended when 80 patients were enrolled in the study. Seven patients were outside the original age limits. The subjects were randomly allocated to each of the 2 groups resulting in 40 patients per group (20 men, 20 women). No patient was lost to follow-up, and all completed the study; thus, all analyses were intention-to-treat.

Fig 1
Consolidated Standards of Reporting Trials flow diagram.

Baseline data

Descriptive statistics of the variables are presented in Table III .

Table III
Descriptive statistics of the main outcome variables
Electric (n = 40) Manual (n = 40)
Average (SD) or count (%) Median (IQR) Average (SD) or count (%) Median (IQR)
Sex, female 20 (50%) 20 (50%)
T0, baseline
Age, y 14.3 (1.43) 14.08 (2.11) 13.8 (1.55) 13.75 (2.20)
PI-M 0.31 (0.10) 0.30 (0.14) 0.32 (0.11) 0.32 (0.17)
FMPS-M 0.92 (0.14) 0.97 (0.12) 0.91 (0.14) 0.97 (0.10)
GI-M 0.62 (0.13) 0.67 (0.23) 0.62 (0.13) 0.64 (0.21)
GIS-M 0.92 (0.16) 1.00 (0.10) 0.91 (0.14) 1.00 (0.16)
T1-T0, d 31.8 (14.92) 28.0 (2.0) 34.5 (13.53) 33.0 (8.3)
PI-M 0.29 (0.10) 0.27 (0.15) 0.30 (0.10) 0.29 (0.12)
FMPS-M 0.89 (0.14) 0.95 (0.15) 0.89 (0.14) 0.95 (0.15)
GI-M 0.61 (0.12) 0.59 (0.16) 0.63 (0.12) 0.66 (0.14)
GIS-M 0.92 (0.13) 1.00 (0.11) 0.92 (0.15) 1.00 (0.08)
T2-T1, d 33.7 (15.80) 28.0 (14.0) 30.3 (11.99) 28.0 (10.3)
PI-M 0.29 (0.09) 0.27 (0.13) 0.29 (0.07) 0.29 (0.08)
FMPS-M 0.91 (0.12) 0.95 (0.11) 0.91 (0.11) 0.95 (0.12)
GI-M 0.60 (0.12) 0.61 (0.15) 0.63 (0.11) 0.64 (0.11)
GIS-M 0.90 (0.16) 1.00 (0.17) 0.92 (0.12) 0.97 (0.10)
T3-T2, d 30.2 (9.44) 28.0 (14.0) 31.9 (11.47) 28.5 (20.3)
PI-M 0.29 (0.10) 0.28 (0.10) 0.29 (0.08) 0.29 (0.11)
FMPS-M 0.92 (0.12) 0.97 (0.10) 0.92 (0.10) 0.95 (0.10)
GI-M 0.62 (0.13) 0.64 (0.14) 0.62 (0.10) 0.64 (0.12)
GIS-M 0.91 (0.15) 1.00 (0.15) 0.92 (0.14) 1.00 (0.11)
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Oct 30, 2021 | Posted by in Orthodontics | Comments Off on A randomized, 3-month, parallel-group clinical trial to compare the efficacy of electric 3-dimensional toothbrushes vs manual toothbrushes in maintaining oral health in patients with fixed orthodontic appliances
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