Plaque · Orthodontic patients undergoing comprehensive treatment (late mixed or permanent dentition, no active caries)
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).
6 findings from 1 review
Show 3 more findings
White spot lesion incidence · Orthodontic patients undergoing comprehensive treatment (late mixed or permanent dentition, no active caries)
Most studies reported a lower incidence of white spot lesions with clear aligners than fixed appliances, but heterogeneous assessment methods precluded meta-analysis (ungraded).
1 finding from 1 review
Severity of white spot lesions (surface area and depth) · Orthodontic patients undergoing comprehensive treatment (late mixed or permanent dentition, no active caries)
White spot lesion severity was assessed narratively in a small number of studies and not meta-analyzed; evidence is limited (ungraded).
1 finding from 1 review
Salivary caries-associated bacteria (S. mutans and Lactobacilli, subjects with >10^5 CFU/mL) · Orthodontic patients undergoing comprehensive treatment (late mixed or permanent dentition, no active caries)
Both included studies reported higher salivary caries-associated bacteria (S. mutans and Lactobacilli) with fixed appliances than clear aligners; not meta-analyzed (ungraded).
1 finding from 1 review
Plaque · Adults undergoing orthodontic treatment
Aligners may reduce plaque index compared with fixed appliances in adults at 6-12 weeks (MD -0.58, 95% CI -0.82 to -0.34; very low certainty).
1 finding from 1 review
Lactobacilli presence (CFU > 10^5) · Adults undergoing orthodontic treatment
Aligners probably lower the risk of high lactobacilli counts versus fixed appliances in adults at 3 months (RR 0.09, 95% CI 0.02 to 0.47; low certainty).
2 findings from 1 review
Average fluorescence loss (dF%) · Adults undergoing orthodontic treatment
A single study reported lower average fluorescence (mineral) loss with aligners versus fixed appliances in adults at 3 months (MD -1.40, 95% CI -2.15 to -0.65; ungraded).
1 finding from 1 review
MD -1.40 [-2.15, -0.65]
1 study
GRADE not reported
Plaque · Adolescents/teenagers undergoing orthodontic treatment
A single study reported a lower full-mouth plaque score with aligners versus fixed appliances in adolescents at 12 months (MD -43.48, 95% CI -47.65 to -39.31; ungraded).
3 findings from 1 review
MD -43.48 [-47.65, -39.31]
1 study
GRADE not reported
MD -0.40 [-0.77, -0.03]
1 study
GRADE not reported
MD -14.78 [-16.74, -12.82]
1 study
GRADE not reported
Gingival index (GI) · Adolescents/teenagers undergoing orthodontic treatment
A single study reported lower gingival index with aligners versus fixed appliances in adolescents at 18 months (MD -0.57, 95% CI -0.93 to -0.21; ungraded).
1 finding from 1 review
MD -0.57 [-0.93, -0.21]
1 study
GRADE not reported
S. mutans presence (CFU > 10^5) · Adults undergoing orthodontic treatment
Aligners probably lower the risk of high S. mutans counts versus fixed appliances in adults at 3 months (RR 0.07, 95% CI 0.01 to 0.49; low certainty).
2 findings from 1 review
Gingival index (GI) · Adults undergoing orthodontic treatment
A single study found no significant difference in gingival index between aligners and fixed appliances in adults at 6-12 weeks (MD -0.10, 95% CI -0.35 to 0.15; ungraded).
1 finding from 1 review
MD -0.10 [-0.35, 0.15]
1 study
GRADE not reported
White spot lesions (WSLs), tooth level · Adults undergoing orthodontic treatment
A single study reported a lower risk of white spot lesions (tooth level) with aligners versus fixed appliances in adults at 3 months (RR 0.72, 95% CI 0.60 to 0.86; ungraded).
1 finding from 1 review
RR 0.72 [0.60, 0.86]
1 study
GRADE not reported
Percentage of bleeding on probing (BOP) · Adults undergoing orthodontic treatment
No clear difference in bleeding on probing between aligners and fixed appliances in adults at 6-12 weeks (MD -0.26, 95% CI -0.77 to 0.26; very low certainty).
1 finding from 1 review
Gingival inflammation-related index · Adolescents/teenagers undergoing orthodontic treatment
A single study reported lower simplified gingival index with aligners versus fixed appliances in adolescents at 1 month (MD -8.46, 95% CI -10.47 to -6.45; ungraded).
1 finding from 1 review
MD -8.46 [-10.47, -6.45]
1 study
GRADE not reported
Probing pocket depth (PPD/PD) · Adults undergoing orthodontic treatment
Aligners may reduce pocket depth compared with fixed appliances in adults at 6-12 weeks (MD -0.42 mm, 95% CI -0.71 to -0.12; very low certainty).
1 finding from 1 review
White spot lesions (WSLs), patient level · Adolescents/teenagers undergoing orthodontic treatment
A single study found no significant difference in white spot lesion formation (patient level) between aligners and fixed appliances in adolescents at 9 months (RR 0.33, 95% CI 0.10 to 1.04; ungraded).
1 finding from 1 review
RR 0.33 [0.10, 1.04]
1 study
GRADE not reported
S. mutans presence · Adolescents/teenagers undergoing orthodontic treatment
A single study found no significant difference in S. mutans presence between aligners and fixed appliances in adolescents at 1 month (RR 0.86, 95% CI 0.64 to 1.14; ungraded).
1 finding from 1 review
RR 0.86 [0.64, 1.14]
1 study
GRADE not reported
Full-mouth bleeding score (FMBS) · Adolescents/teenagers undergoing orthodontic treatment
A single study reported a lower full-mouth bleeding score with aligners versus fixed appliances in adolescents at 12 months (MD -20.44, 95% CI -22.98 to -17.90; ungraded).
1 finding from 1 review
Lesion area (decalcification area, pixels) · Adults undergoing orthodontic treatment
A single study reported a larger decalcification lesion area with aligners versus fixed appliances in adults at 3 months (MD 80.50 pixels, 95% CI 60.52 to 100.48; ungraded).
1 finding from 1 review
MD 80.50 [60.52, 100.48]
1 study
GRADE not reported
S. mutans counts (5th-root transformed) · Adolescents/teenagers undergoing orthodontic treatment
A single study found no significant difference in S. mutans counts between aligners and fixed appliances in adolescents at 1 month (MD -2.22, 95% CI -6.82 to 2.38; ungraded).
1 finding from 1 review
MD -2.22 [-6.82, 2.38]
1 study
GRADE not reported