Five years of evidence: a retrospective analysis of clinical trials comparing electric and manual toothbrush effectiveness in orthodontic patients

Study Protocol

This review was conducted in accordance with the guidelines of the Cochrane Handbook for systematic reviews of interventions (12) (13) and the PRISMA guidelines (13).

Eligibility criteria

The methodology is based on the PICO search criteria (Table 1) from studies of patients undergoing orthodontic treatment with fixed therapy using electric or manual toothbrushes. The inclusion criteria adopted were the following: random clinical studies; studies in which the ability to brush the teeth with manual and electric toothbrushes was compared in orthodontic patients.

Exclusion criteria were: studies in which subjects with periodontal disease were considered; systematic reviews or meta-analyses; studies in which fixed therapy was performed with ceramic or lingual brackets.

Data extraction

Two independent reviewers (C.F. and A.P.) searched PubMed for literature published in English from January 2020 to June 2025, using the above-mentioned inclusion criteria. The search string was finalized using both FREE TEXT TERMS and MESH terms as below: (((orthodontics[MeSH Terms]) OR (orthodontic*)) AND ((toothbrushing[MeSH Terms]) OR (toothbrushing))) AND ((((orthodontics[MeSH Terms]) OR (orthodontic*)) AND ((toothbrushing[MeSH Terms]) OR (toothbrushing))) OR ((((((((((manual*) OR (conventional*)) OR (hand brush*)) OR (power*)) OR (mechanical*)) OR (electric*)) OR (electronic)) OR (ultrasonic*)) OR (sonic*)) OR (“motor driven”))). Filters: articles in English. Duplicate articles were removed. The eligibility of the studies was independently assessed by two authors (C.F., A.P.), who initially reviewed the titles and abstracts of the reviews. The full texts were consulted whenever it was unclear whether the review should be included. In case of disagreement, this was resolved through discussion and consensus with a third author, an expert who was asked to arbitrate (B.R.).

Data collection and data synthesis

The two authors (A.P., C.F.) independently selected the data (authors, year of publication, study design, sample size, sample composition by sex and age, primary and secondary outcomes, evaluation method, sampling intervals, and criteria for inclusion and exclusion) of the selected studies using a predefined extraction form. Any disagreements were resolved through discussion and consensus by a third expert author who was asked to arbitrate (B.R.).

For each study included in this review, the following data were collected:

• - The first author, year, journal, and funding
• - The characteristics of the population: sample size, age range, and sex ratio
• - The intervention group data: electronic toothbrush (type, characteristics, duration, and follow-up)
• - Control group data: manual toothbrush (type, characteristics, duration, and follow-up)
• - Statistically significant study results
• - The study conclusions

Quality Assessment

Two authors (C.F. and A.P.) independently assessed the Risk of Bias of the included studies using the Risk of Bias (ROB2) tool developed by the Cochrane Collaboration. (14). It consists of 5 domains: for each domain, a signaling question is proposed to guide the assessment of methodological quality and to facilitate understanding of how the RoB 2 tool operates and the different sources of potential bias in clinical studies. (Table 2)

Any disagreements were initially resolved through discussion or, if necessary, in collaboration with a third author (G.D.D.).

DOMAIN	QUESTION	ANSWER
Risk of bias arising from the randomization process	Was the allocation sequence random? Were all participants identified before randomization?
Risk of bias due to deviations from the intended interventions	Were participants and personnel aware of the assigned intervention? Could this awareness have led to significant deviations from the intended intervention?”
Risk of bias due to missing outcome data	Are the missing outcome data sufficiently extensive to have a notable impact? Is the missingness likely to depend on the true value of the outcome, potentially affecting the results?
Risk of bias in the measurement of the outcome	Were outcome assessors blinded to the intervention assignment? Were the methods of outcome measurement appropriate for the outcome in question?
Risk of bias in the selection of the reported result	Were the reported results analyzed in accordance with a pre-specified analysis plan?

Selected studies

An electronic search on PubMed yielded 666 results from January 2020 to June 2025. Of these, 640 titles were discarded as clearly not relevant, while 26 abstracts were screened. In total, four studies were included in this review of systematic reviews. A PRISMA flowchart for the study selection process is presented in Figure 1. A qualitative summary of the studies included is presented in Table 3.

Narrative synthesis of the studies

The first article analyzed, authored by Erden et al. (15), is a randomized clinical trial conducted at a single center and examiner-blinded. The primary objective was to determine which type of toothbrush proved more effective in dental plaque control, reduction of gingival inflammation and bleeding on probing, as well as to assess changes in salivary levels of cariogenic bacteria such as Streptococcus mutans, Lactobacillus casei, and Porphyromonas gingivalis. The study involved 40 orthodontic patients aged between 12 and 18 years, all right-handed, fitted with Roth 0.018-inch brackets and metallic ligatures, and who performed manual toothbrushing daily. Inclusion criteria also required the absence of physical or mental disorders and a mean plaque index score of at least 1.75. Exclusion criteria comprised the presence of systemic diseases, regular drug use, tooth rotations or diastemas, additional orthodontic components, poor compliance, smoking, labial surface restorations, and the use of antibiotics or antibacterial agents within the previous three months. Participants were randomly assigned to two groups, each following a distinct oral hygiene protocol: one group used a manual toothbrush (Oral-B Ortho Brush with soft bristles).

In contrast, the other used an electric toothbrush (Oral-B Genius 8900) equipped with a pressure sensor and a two-minute timer. The latter device employs a so-called three-dimensional cleaning technology that combines oscillating, rotating, and pulsating movements to enhance cleaning efficacy. Both groups used the same toothpaste containing 1450 ppm fluoride and were instructed in the modified Bass brushing technique, supported by a demonstrative video. Participants were also instructed not to use any additional oral hygiene aids. Clinical assessments were performed at baseline (T0), after six weeks (T1), and after twelve weeks of follow-up (T2). The results demonstrated greater efficacy of the electric toothbrush in reducing the plaque index (PI), with significantly lower values than those of the manual toothbrush at the subsequent evaluation time points. However, both groups showed a progressive decrease in plaque index scores between baseline and 12 weeks.

Regarding the gingival index (GI) and bleeding on probing (BOP), no statistically significant differences were observed between the two groups, although both exhibited improvement over time. Regarding bacterial parameters, Streptococcus mutans levels were higher in the electric toothbrush group, although these differences were not statistically significant throughout the study period. Porphyromonas gingivalis levels showed non-significant variations, while Lactobacillus casei exhibited no differences between the groups at any of the evaluation points. In summary, the study highlights that an interactive electric toothbrush may be an effective tool for improving plaque control in patients undergoing orthodontic treatment, with potential positive effects on patient motivation and compliance. Despite the observed clinical efficacy in plaque management, the impact of the electric toothbrush on cariogenic bacterial levels warrants further investigation to achieve a more comprehensive understanding.

Bilen et al. (16) designed a parallel-group randomized clinical trial to investigate the short-term effects of manual and electric toothbrush use on patients’ periodontal status undergoing fixed orthodontic treatment. A total of 36 patients aged 12–18 years, all presenting with permanent dentition and indications for non-extraction orthodontic therapy, were selected for the study. Inclusion criteria comprised right-handed patients with no prior experience using an electric toothbrush and homogeneity in bracket type and ligation technique. Exclusion criteria included the absence of missing teeth, the presence of systemic or periodontal diseases, physical impairments that could affect toothbrushing, and the use of narcotic substances within the previous two months. Participants were randomly allocated into two distinct groups: one group used a manual toothbrush with an orthodontic head and employed the modified Bass brushing technique, supported by an instructional video; the other group used an electric toothbrush (Oral-B Interactive 8900) in conjunction with a smartphone application provided by the manufacturer, containing usage instructions. Both groups brushed twice daily for two minutes using the same toothpaste. The manual toothbrush group used an external timer, whereas the electric toothbrush group used the device’s built-in timer. Throughout the study period, the use of additional oral hygiene aids was prohibited. The follow-up period lasted four months, with assessments conducted at baseline (T0), after 4 weeks (T1), 2 months (T2), and 4 months (T3). The clinical parameters monitored included the modified Silness and Löe plaque index (PI), the gingival index (GI), and bleeding on probing (BOP), with particular attention to gingival inflammation observed within 30 seconds of bleeding. The results demonstrated a significant reduction in plaque index in the electric toothbrush group at all evaluation time points.

In contrast, the manual toothbrush group exhibited smaller changes, particularly between two (T2) and four months (T3). Changes in the gingival index followed a pattern similar to that of bleeding on probing in the electric toothbrush group, with significant improvements throughout the observation period. Both groups showed significant reductions in BOP from baseline to the subsequent evaluations at two and four months; however, the electric toothbrush group also demonstrated a significant improvement between one and four weeks. No statistically significant differences between the groups were observed regarding bleeding on probing. In conclusion, the study by Bilen et al. indicates that the use of an electric toothbrush results in statistically significant improvements in the plaque and gingival indices compared to a manual toothbrush in orthodontic patients over the short term. These findings support the efficacy of electric toothbrushes in enhancing periodontal health in this vulnerable population, highlighting the importance of appropriate oral hygiene tools for patients undergoing fixed orthodontic treatment.

In contrast, the study by Johal et al. (17) was a randomized, controlled, parallel-group clinical trial comparing the long-term efficacy of manual and electric toothbrushing in adolescent patients undergoing fixed orthodontic treatment. A total of 92 patients aged 12–18 years, in good general health and non-smokers, were included in the study. Exclusion criteria ruled out individuals with prior experience using electric toothbrushes, patients with special needs or learning difficulties, a history of periodontitis or attachment loss, those who had undergone oral prophylaxis within the previous four weeks, or those who had used antibacterial mouthwashes or antibiotics in the past month. Patients with five or more active carious lesions requiring immediate treatment were also excluded. Participants were randomly assigned to two groups: one group used a manual toothbrush (Oral-B Indicator Medium 35), and the other used a sonic electric toothbrush (ProClinical A1500). The sonic toothbrush generates high-frequency vibrations, typically exceeding 30,000 oscillations per minute, producing a fluid-dynamic effect within the oral cavity. This action is not limited to the mechanical cleaning achieved by direct bristle contact with the tooth surface; it also creates turbulence within the fluid mixture of saliva and toothpaste. This phenomenon enhances the removal of bacterial plaque in interdental areas and along the gingival margins, regions that are otherwise difficult to reach with conventional mechanical action. All participants were provided with toothpaste containing 1450 ppm fluoride and were instructed to maintain adequate oral hygiene by brushing twice daily for at least two minutes.

The use of interdental brushes was also encouraged to improve cleaning around the fixed appliances. The electric toothbrush group received additional instructional support regarding device maintenance, including charging and periodic replacement of brush heads, reinforced by a demonstrative video. The study follow-up lasted 12 months, with assessments conducted at baseline (T0), 1 month (T1), 6 months (T2), and 12 months (T3). The clinical parameters evaluated included the plaque index (PI), the gingival index (GI), and bleeding on probing (BOP). Final results revealed no statistically significant differences between the two groups in plaque index, gingival index, or bleeding on probing at any evaluation time point. However, deterioration in plaque control and periodontal parameters was observed over the follow-up, likely due to the intrinsic complexity of maintaining proper oral hygiene with fixed orthodontic appliances. In conclusion, the study by Johal et al. demonstrates that, both in the short and long term, there are no significant differences in plaque control and gingival health between manual and electric toothbrushes in adolescent patients with fixed orthodontic appliances. This finding highlights that neither brushing method alone is sufficient to ensure adequate oral hygiene in this population, underscoring the importance of ongoing clinical support and personalized motivational strategies throughout orthodontic treatment.

The study conducted by Mylonopoulou et al. (18)was a single-blind, parallel-group randomized clinical trial designed to compare the effectiveness of three-dimensional electric toothbrushes with manual toothbrushes in maintaining oral health in patients with fixed orthodontic appliances. A total of 80 patients aged 12–16 years, in good general health, undergoing non-extraction fixed orthodontic treatment with uniform metal components on both arches, were included in the study. Moderate plaque-induced gingivitis was a prerequisite for inclusion. Exclusion criteria included active caries, periodontitis, agenesis, syndromic conditions or craniofacial defects, current use of electric toothbrushes, more than two cervical or proximal restorations, prostheses or dental implants, disabilities affecting toothbrushing, peri- or intraoral piercings, need for antibiotic prophylaxis, smoking or tobacco use, and antibiotic intake within the previous two months. Participants were randomly assigned to two groups: one group received a manual toothbrush (Oral-B orthodontic brush), while the other received a three-dimensional electric toothbrush (Oral-B Pro-1000). All participants received standardized instruction on brushing technique, with the recommendation to brush twice daily for two minutes. During the three-month follow-up, with assessments at baseline (T0), one month (T1), two months (T2), and three months (T3), participants were instructed to use the provided toothbrushes and toothpaste exclusively and to report any dental visits during the study period. The outcomes assessed included the Modified Silness and Löe Plaque Index, the Modified Full Mouth Plaque Score, and the Modified Gingival Index. The results demonstrated significant individual variability in outcomes, with no statistically significant differences between the three-dimensional electric toothbrush group and the manual toothbrush group in plaque reduction or gingival inflammation at any evaluation time point. In conclusion, the study by Mylonopoulou et al. demonstrates that, over a short-term period of three months, there are no substantial differences in efficacy between three-dimensional electric toothbrushes and manual toothbrushes for plaque control and management of gingival inflammation in adolescent patients with fixed orthodontic appliances. These findings highlight the need for further research to clarify potential long-term clinical benefits.

Quality of the Included Studies

The randomized clinical trial by Erden et al. (15) provides a detailed and controlled description of the randomization process, significantly reducing the likelihood of bias. Although there were no relevant deviations from the planned intervention, some concerns were noted due to the single examiner’s blinding. The 12-week follow-up was complete and adequately structured, with no reports of unaddressed dropouts or losses, thereby minimizing the risk associated with incomplete outcome data. Outcome assessment appears reliable, owing to examiner blinding, which limits potential influences on the measurement of plaque, gingival, and microbiological indices. Reporting was consistent and comprehensive with respect to the pre-specified outcomes, with no evidence of selective reporting or omission of results that could compromise overall transparency; however, the selection protocol was not preregistered. Overall, the study demonstrates a solid experimental design, although the lack of participant blinding and preregistration raises some concerns.

The randomization process in Bilen et al.’s study. (16) is clearly and appropriately described, with procedures that minimize the risk of errors in allocating participants to experimental groups. However, as the randomization process was simple, some concerns arose regarding the adequacy of the method employed. Interventions were conducted in accordance with the pre-established protocol, with only minor deviations from the planned intervention and with equivalent conditions maintained between the comparison groups. This reduces the risk of bias related to deviations from the intended intervention. Some losses to follow-up were reported; however, single-examiner blinding introduces slight uncertainty regarding the risk associated with deviations from the intervention, representing a moderate concern in this domain. Outcome measurement was conducted by blinded evaluators using standardized and validated tools and methods, ensuring high reliability and limiting subjective influence on the assessments. Finally, reporting of the results was complete and consistent with the predefined protocol, with no evidence of selective reporting or omission of outcomes, thereby ensuring transparency and accuracy in data communication. Nevertheless, retrospective registration raises some concerns. In summary, the study demonstrates a moderate overall risk of bias, with slight uncertainty limited to the randomization process and the selection of reported results, which should be considered in the critical interpretation of the findings.

The randomization procedure in the study by Johal et al. (17) was clearly described and rigorously implemented, ensuring a correct and random allocation of participants to the different experimental groups and minimizing the risk of assignment-related bias. No significant deviations from the planned interventions were observed, ensuring that all participants followed homogeneous treatment protocols and that study conditions remained consistent across groups. Single-examiner blinding raises some concerns. The follow-up was complete and thoroughly documented, substantially reducing the possibility of bias arising from missing data or unaddressed losses in outcome assessment. Outcomes were measured by blinded evaluators using validated and standardized tools, ensuring impartiality and reliability in clinical and microbiological measurements. Reporting of results was consistent with the prescribed protocol, with no evidence of omissions or selective presentation, confirming the transparency and completeness of the research. In conclusion, the study demonstrates a low overall risk of bias, providing robust and reliable data for clinical evaluation, with high methodological quality across the design, execution, and reporting phases.

The randomization process in the study by Mylonopoulou et al. (18) was described in detail and rigorously implemented, ensuring a correct random allocation of participants to the two experimental groups and minimizing the risk of allocation-related bias. No significant deviations from the planned interventions were observed, ensuring that participants adhered faithfully to the assigned brushing protocols and that intervention conditions remained consistent. However, single-examiner blinding introduces a moderate risk of bias in this domain. The follow-up was complete and carefully documented, with regular assessments minimizing the impact of any losses or missing data on the evaluation of clinical outcomes. Nonetheless, single-examiner blinding introduces a moderate risk in this domain. Outcome measurements were conducted by blinded evaluators using validated methodologies and standardized instruments, ensuring objectivity and reliability in clinical assessments. Finally, reporting of results was transparent and consistent with the original study protocol, with no omissions or selective data presentation that could compromise research integrity. Some concerns arise from the lack of preregistration of the protocol. Overall, the study demonstrates a moderate risk of bias, providing solid and reliable data for clinical interpretation and confirming a high level of methodological rigor across the different phases of the research.