Non-Cochrane · intervention · PM37635207
White spot lesions, plaque accumulation and salivary caries-associated bacteria in clear aligners compared to fixed orthodontic treatment. A systematic review and meta- analysis.
Raghavan Shailaja, Abu Alhaija Elham S, Duggal Mandeep Singh, et al. · BMC oral health · 2023 · PubMed · doi:10.1186/s12903-023-03257-8
Oral HealthDental cariesOral medicine and oral cancerOrthodonticsPeriodontologyAMSTAR 2: Critically Low / Low (extractors disagree)
Full textEvery question was extracted from the full text, figures and supplements by two independent LLM extractors, disagreements adjudicated. Rows cite where in the review the value comes from.
Questions
9
current version
GRADE rated
2
No studies
0
Included studies
14
linked below
No studies 0 · 0%Ungraded 7 · 77.8%Very low 0 · 0%Low 0 · 0%Moderate 2 · 22.2%High 0 · 0%
Ungraded means an effect was reported without a GRADE rating; it is not a gap. No studies means the review found nothing to answer the question. The six categories are a display order, not a score.
Review question
| Element | Planned (methods) | Found (results) |
|---|---|---|
| Population | Patients with normal general health requiring comprehensive orthodontic treatment; late mixed or permanent dentition; no active caries lesion; excluding pre-existing periodontal/salivary gland disease or antibiotic/analgesic use | Orthodontic patients; 14 included studies (5 RCTs, 9 NRSI); 8 studies meta-analyzed for plaque accumulation (n=14 studies) |
| Intervention | Clear aligners | Clear aligners (n=14 studies) |
| Comparison | Conventional fixed orthodontic appliances (self-ligating brackets and lingual appliances excluded) | Conventional fixed appliances (n=14 studies) |
| Outcomes | Incidence of WSLs; severity (depth and surface area) of WSLs; plaque index; salivary cariogenic bacteria (Streptococcus mutans and Lactobacillus acidophilus) | Plaque accumulation meta-analyzed (pooled SMD -1.58, 95% CI -2.57 to -0.58; 8 studies); WSL incidence (4 studies), WSL severity (2 studies) and SCB (2 studies) synthesized narratively (not meta-analyzed) |
| Study designs | RCTs and cohort studies (cross-sectional, case-control, case reports and case series excluded) | 5 RCTs and 9 non-randomized studies of interventions (n=14 studies) |
| Timing | Not specified (plaque index assessed at varying time-points; maximum time-point used for the primary analysis) | Follow-up 1-18 months; plaque index meta-analyzed at each study's maximum time-point and separately at 3, 6 and 12 months |
Search date: May 2023 (searched January 2022 to May 2023; literature 1990-May 2023). Databases: MEDLINE via PubMed; Scopus; Embase; Google Scholar; OpenGrey; ProQuest Dissertations & Theses; ClinicalTrials.gov (registry)
Questions and results
Clear aligners (CA) vs Conventional fixed orthodontic appliances (CF)
Population: Orthodontic patients undergoing comprehensive treatment (late mixed or permanent dentition, no active caries)
| Outcome | Effect | Evidence | Status / GRADE |
|---|---|---|---|
Severity of white spot lesions (surface area and depth) Baseline to end of treatment (varying) White spot lesion severity was assessed narratively in a small number of studies and not meta-analyzed; evidence is limited (ungraded). Source: Results 'White spot lesions'; Table 3; Discussion · same question in other reviews | Not meta-analyzed. 2 RCTs assessed WSL severity by lesion surface area (Albhaisi 2020 [12]; Alshatti 2017 [31]) and 1 (Albhaisi 2020 [12]) also by lesion depth; reported narratively with differing methods, generally… | 2 studies | Ungraded |
Plaque accumulation (Plaque Index) Range 1 to 12 months (maximum time-point per study) · Study design: non-randomized studies of interventions In non-randomized studies, clear aligners probably reduce plaque accumulation versus fixed appliances (SMD -1.46, 95% CI -2.77 to -0.15; moderate certainty). Source: Results 'Quality of evidence'; Table 6 (GRADE evidence profile, NRSI row); Fig. 5 (subgroup forest, NRSI) · same question in other reviews | SMD -1.46 [-2.77, -0.15] | 5 studies · 246 participants | Moderate Downgraded: risk of bias, inconsistency |
Plaque accumulation (Plaque Index) 6 months · Follow-up: 6 months At 6 months, clear aligners were associated with significantly less plaque accumulation than fixed appliances (SMD -2.04, 95% CI -3.37 to -0.70; ungraded). Source: Results 'Plaque accumulation'; Fig. 6b (6-month forest plot) · same question in other reviews | SMD -2.04 [-3.37, -0.70] | 5 studies · 253 participants | Ungraded |
Plaque accumulation (Plaque Index) Range 1 to 18 months (maximum time-point per study) · Study design: randomized controlled trials In randomized trials, clear aligners probably reduce plaque accumulation versus fixed appliances, though the subgroup estimate is imprecise and its CI crosses no effect (SMD -1.79, 95% CI -3.63 to 0.04; moderate certainty). Source: Results 'Quality of evidence'; Table 6 (GRADE evidence profile, randomised trials row); Fig. 5 (subgroup forest, RCT) · same question in other reviews | SMD -1.79 [-3.63, 0.04] | 3 studies · 111 participants | Moderate Downgraded: risk of bias, inconsistency |
Incidence of white spot lesions (WSLs) End of orthodontic treatment (varying) Most studies reported a lower incidence of white spot lesions with clear aligners than fixed appliances, but heterogeneous assessment methods precluded meta-analysis (ungraded). Source: Results 'White spot lesions'; Table 3 · same question in other reviews | Not meta-analyzed (heterogeneous methods; tooth-based vs patient-based incidence). 4 studies assessed WSL incidence; 3 (Albhaisi 2020 [12]; Buschang 2019 [29]; Dallel 2020 [30]) reported a lower risk of developing WSLs… | 4 studies | Ungraded |
Salivary caries-associated bacteria (S. mutans and Lactobacilli, subjects with >10^5 CFU/mL) 3 and 6 months Both included studies reported higher salivary caries-associated bacteria (S. mutans and Lactobacilli) with fixed appliances than clear aligners; not meta-analyzed (ungraded). Source: Results 'Salivary caries-associated bacteria'; Table 5 · same question in other reviews | Not meta-analyzed (insufficient number of studies). Both included observational studies (Mummolo 2020 [19]; Mummolo 2020 [25]) reported a higher number of subjects with S. mutans and Lactobacilli >10^5 CFU/mL in the… | 2 studies | Ungraded |
Plaque accumulation (Plaque Index) 3 months · Follow-up: 3 months At 3 months, clear aligners were associated with significantly less plaque accumulation than fixed appliances (SMD -1.08, 95% CI -1.93 to -0.24; ungraded). Source: Results 'Plaque accumulation'; Fig. 6a (3-month forest plot) · same question in other reviews | SMD -1.08 [-1.93, -0.24] | 5 studies · 211 participants | Ungraded |
Plaque accumulation (Plaque Index) Maximum reported time-point per study (range 1-18 months) Clear aligners are associated with significantly less plaque accumulation than conventional fixed appliances (pooled SMD -1.58, 95% CI -2.57 to -0.58); certainty graded moderate within study-design subgroups. Source: Abstract; Results 'Results of individual studies and meta-analysis - Plaque accumulation'; Fig. 4 (forest plot, overall diamond) · same question in other reviews | SMD -1.58 [-2.57, -0.58] | 8 studies · 357 participants | Ungraded |
Plaque accumulation (Plaque Index) 12 months · Follow-up: 12 months At 12 months, clear aligners were associated with significantly less plaque accumulation than fixed appliances (SMD -2.14, 95% CI -3.64 to -0.64; ungraded). Source: Results 'Plaque accumulation'; Fig. 6c (12-month forest plot) · same question in other reviews | SMD -2.14 [-3.64, -0.64] | 3 studies · 113 participants | Ungraded |
AMSTAR 2 appraisal
Two independent extractors rated each item. Their ratings are shown side by side because they have not been reconciled yet. The overall rating follows Shea et al. 2017: one critical flaw gives Low, more than one gives Critically Low.
| Item | Extractor A | Extractor B | Agree |
|---|---|---|---|
| 1Research question includes PICO components | Yes | Yes | yes |
| 2Protocol established before the reviewcritical | Partial Yes | Partial Yes | yes |
| 3Choice of study designs explained | Yes | Yes | yes |
| 4Comprehensive literature searchcritical | Partial Yes | Yes | no |
| 5Study selection in duplicate | Yes | Yes | yes |
| 6Data extraction in duplicate | Yes | Yes | yes |
| 7List of excluded studies with reasonscritical | Yes | Yes | yes |
| 8Included studies described in detail | Yes | Yes | yes |
| 9Risk of bias assessed satisfactorilycritical | RCT: Yes · NRSI: Yes | NRSI: Yes · RCT: Yes | no |
| 10Funding of included studies reported | Yes | Yes | yes |
| 11Appropriate meta-analysis methodscritical | RCT: Yes · NRSI: No | NRSI: Yes · RCT: Yes | no |
| 12Impact of risk of bias on the pooled results | No | No | yes |
| 13Risk of bias accounted for in interpretationcritical | Yes | Yes | yes |
| 14Heterogeneity explained | Yes | Yes | yes |
| 15Publication bias investigatedcritical | No | No | yes |
| 16Conflicts of interest reported | No | No | yes |
| Overall | Critically Low | Low | no |
Included primary studies 14
Open as a trial list| Study | Also included by | Outcomes it informs here | Trial PICO | Results |
|---|---|---|---|---|
| Buschang 2019 Incidence of white spot lesions among patients treated with clear aligners and traditional braces. PMID:30556747 | 1 other review | Salivary caries-associated bacteria (S. mutans and Lactobacilli, subjects with >10^5 CFU/mL) | not extracted yet | not extracted yet |
| Dallel 2020 Influence of orthodontic appliance type on salivary parameters during treatment. PMID:33378497 | 1 other review | Salivary caries-associated bacteria (S. mutans and Lactobacilli, subjects with >10^5 CFU/mL) | not extracted yet | not extracted yet |
| Karkhanechi 2013 Periodontal status of adult patients treated with fixed buccal appliances and removable aligners over one year of active orthodontic… PMID:22725616 | 1 other review | Plaque accumulation (Plaque Index) | not extracted yet | not extracted yet |
| Levrini 2015 Periodontal health status in patients treated with the Invisalign(®) system and fixed orthodontic appliances: A 3 months clinical and… PMID:26430371 | 1 other review | Plaque accumulation (Plaque Index) | not extracted yet | not extracted yet |
| Mummolo 2020 [19] Salivary levels of Streptococcus mutans and Lactobacilli and other salivary indices in patients wearing clear aligners versus fixed… PMID:32330172 | 1 other review | not stated | not extracted yet | not extracted yet |
| Mummolo 2020 [25] Salivary concentrations of Streptococcus mutans and Lactobacilli during an orthodontic treatment. An observational study comparing fixed… PMID:32250562 | 1 other review | not stated | not extracted yet | not extracted yet |
| Pango Madariaga 2020 Impact of Fixed Orthodontic Appliance and Clear Aligners on the Periodontal Health: A Prospective Clinical Study. PMID:31906577 | 1 other review | Plaque accumulation (Plaque Index) | not extracted yet | not extracted yet |
| Abbate 2015 Periodontal health in teenagers treated with removable aligners and fixed orthodontic appliances. PMID:25929710 | this review only | Plaque accumulation (Plaque Index) | not extracted yet | not extracted yet |
| Albhaisi 2020 Enamel demineralization during clear aligner orthodontic treatment compared with fixed appliance therapy, evaluated with quantitative… PMID:32354432 | this review only | Salivary caries-associated bacteria (S. mutans and Lactobacilli, subjects with >10^5 CFU/mL) | not extracted yet | not extracted yet |
| Alshatti 2017 International exercise on 124Sb photon emission intensities determination. PMID:20171111 | this review only | Salivary caries-associated bacteria (S. mutans and Lactobacilli, subjects with >10^5 CFU/mL) | not extracted yet | not extracted yet |
| Chhibber 2018 Which orthodontic appliance is best for oral hygiene? A randomized clinical trial. PMID:29407494 | this review only | Plaque accumulation (Plaque Index) | not extracted yet | not extracted yet |
| Levrini 2013 Assessment of the periodontal health status in patients undergoing orthodontic treatment with fixed or removable appliances. A… DOI:10.7126/cdj.2013.1974 | this review only | Plaque accumulation (Plaque Index) | not extracted yet | not extracted yet |
| Miethke 2005 A comparison of the periodontal health of patients during treatment with the Invisalign system and with fixed orthodontic appliances. PMID:15959635 | this review only | Plaque accumulation (Plaque Index) | not extracted yet | not extracted yet |
| Shokeen 2022 The impact of fixed orthodontic appliances and clear aligners on the oral microbiome and the association with clinical parameters: A… PMID:35248417 | this review only | Plaque accumulation (Plaque Index) | not extracted yet | not extracted yet |
Overlap with other reviews
Reviews that include the same primary studies are not independent evidence. Shared counts match studies by PMID, DOI or NCT, and otherwise by author and year (a probable match).
| Review | Shared studies | Jaccard |
|---|---|---|
| Impact of Aligners and Fixed Appliances on Oral Health during Orthodontic Treatment: A Systematic Review and Meta-Analysis. (2021) | 7 | 0.25 |