What do systematic reviews say?

Mouth-rinse probiotic vs placebo or control

In a subgroup analysis, mouth-rinse probiotics reduced salivary pH (MD -0.40, 95%CI -0.54 to -0.26; p-interaction<0.01); not GRADE-rated.

• Efficacy of Probiotic Consumption on Oral Outcomes in Children and/or Adolescents: A Meta-Analysis. 2024 All outcomes

  Healthy children and/or adolescents (<18 years) without systemic disease; RCTs from multiple countries (India, Thailand, Spain, Australia, New Zealand, Sweden, Poland, Colombia, Saudi Arabia); mostly school/community and clinic settings · Probiotic presentation: mouth rinse (vs other presentations; p-interaction<0.01)
  MD -0.40 [-0.54, -0.26]
  Studies not reported
  GRADE not reported

Intervention not reported

• Teledentistry accuracy for caries diagnosis: a systematic review of in-vivo studies using extra-oral photography… 2024 All outcomes

  Studies reporting Spearman correlation (Almosa 2014, Daniel 2017, Zotti 2022)
  Spearman correlation coefficient 0.76 to 0.99 (Almosa 0.76; Zotti 0.816; Daniel 0.99)
  3 studies
  GRADE not reported

Disability (developmental, intellectual, or sensory) vs Persons without disabilities

Dental caries prevalence and severity are high among persons with disabilities in Saudi Arabia (60% to over 80%), and the one comparative autism study reported significantly higher caries than controls; synthesized narratively (ungraded).

• Disabilities and Disparities in Oral Health-Related Quality of Life: A Systematic Review and Meta-Analysis in Saudi… 2024 All outcomes

  Cross-sectional · Autism centres and dental/hospital settings in Saudi Arabia (Riyadh, Jeddah)
  Narrative synthesis (no pooled estimate). High dental caries burden among PWDs: caries prevalence 60% to over 80% (abstract). Alkahtani 2019 (hearing-impaired adults, single-arm): caries prevalence 82.2%, treatment…
  Studies not reported
  GRADE not reported

Teledentistry (index test): dental caries diagnosis from photographs taken with DSLR or smartphone cameras; store-and-forward vs Visual or clinical examination

Across 13 studies, the specificity of teledentistry caries diagnosis ranged from 83% to 100%; no pooled estimate and certainty not graded.

• Teledentistry accuracy for caries diagnosis: a systematic review of in-vivo studies using extra-oral photography… 2024 All outcomes

  Cross-sectional diagnostic accuracy (index test vs reference standard, in-vivo) · In-vivo: dental clinics/hospitals, schools, and a juvenile detention facility (11 countries) · Overall (studies reporting specificity; narrative synthesis)
  Specificity ranged from 83% to 100% across studies (reported in 13 of 19 studies). No pooled estimate; meta-analysis not performed.
  13 studies
  GRADE not reported

Cleft lip and/or palate (CL/P) vs No cleft lip and/or palate (non-CL/P)

No significant difference in Lactobacillus spp. presence was reported; GRADE was not reported.

• Characterization of the oral microbiota and the relationship of the oral microbiota with the dental and periodontal… 2024 All outcomes
  MD 1.40 [1.33, 1.47]
  2 studies · 152 participants
  GRADE not reported

Probiotics vs placebo or control

Probiotics may make little to no difference to Lactobacillus count versus control (MD -0.78 CFU/mL, 95%CI -1.65 to 0.09; very low certainty).

• Efficacy of Probiotic Consumption on Oral Outcomes in Children and/or Adolescents: A Meta-Analysis. 2024 All outcomes

  follow-up: mean 5.2 months · Healthy children and/or adolescents (<18 years) without systemic disease; RCTs from multiple countries (India, Thailand, Spain, Australia, New Zealand, Sweden, Poland, Colombia, Saudi Arabia); mostly school/community and clinic settings · Overall (all presentations pooled)
  MD -0.78 [-1.65, 0.09]
  6 studies · 1143 participants
  Very low

Slum / urban-disadvantaged setting vs Non-slum urban / general-urban / national population

Dental service use is low, episodic and pain-driven, with widespread self-care and cost/funding barriers; ungraded.

• Systematic review of oral health in slums and non-slum urban settings of Low and Middle-Income Countries (LMICs):… 2024 All outcomes

  Urban slums and non-slum/general-urban settings, LMICs
  Utilisation was generally low, episodic and mostly problem/pain-driven (pain-driven visits ~70-99%); widespread self-care/home remedies were used as alternatives to professional care; lack of funds/cost, income, age,…
  Studies not reported
  GRADE not reported

Slum / urban-disadvantaged setting vs Non-slum urban / general-urban / national population

Twice-daily cleaning (recommended) is uncommon; most clean once, in the morning; ungraded.

• Systematic review of oral health in slums and non-slum urban settings of Low and Middle-Income Countries (LMICs):… 2024 All outcomes

  Cross-sectional · Urban slums and non-slum/general-urban settings, LMICs · Slum/disadvantaged vs non-slum/urban
  Mouth cleaning was mostly once daily and in the mornings; only a small proportion cleaned at least twice daily (e.g., Osuh 24% slum vs 27% non-slum; Singh 3%; Habib 3.5%; Hewlett 69%). A similar slum/disadvantaged vs…
  Studies not reported
  GRADE not reported

Intervention not reported

• Characterization of the oral microbiota and the relationship of the oral microbiota with the dental and periodontal… 2024 All outcomes

  Narrative synthesis: significantly higher in CLP vs controls (Ahluwalia, Lucas, Hassani, Cheng, Sundell)
  no estimate extracted
  5 studies
  GRADE not reported

Slum / urban-disadvantaged setting vs Non-slum urban / general-urban / national population

Dental caries prevalence in LMIC urban/slum populations ranges widely (13%-76%); not GRADE-rated (narrative synthesis).

• Systematic review of oral health in slums and non-slum urban settings of Low and Middle-Income Countries (LMICs):… 2024 All outcomes

  Cross-sectional · Urban slums and non-slum/general-urban settings, LMICs
  Prevalence of dental caries varied across age, gender and socioeconomic class, ranging from 13% (Nigeria) to 76% (Central India); prevalence >50% reported in India, Brazil, Malaysia and Rwanda; generally higher in…
  14 studies
  GRADE not reported

Teledentistry (index test): dental caries diagnosis from photographs taken with DSLR or smartphone cameras; store-and-forward vs Visual or clinical examination

Positive predictive value was reported in 10 studies and varied widely across studies (about 42% to 99%); no pooled estimate and certainty not graded.

• Teledentistry accuracy for caries diagnosis: a systematic review of in-vivo studies using extra-oral photography… 2024 All outcomes

  Cross-sectional diagnostic accuracy (index test vs reference standard, in-vivo) · In-vivo: dental clinics/hospitals, schools, and a juvenile detention facility (11 countries) · Overall (studies reporting PPV; narrative synthesis)
  PPV 41.8% to 99%
  10 studies
  GRADE not reported

Probiotics vs placebo or control

Probiotics may make little to no difference to salivary pH versus control (MD -0.12 pH units, 95%CI -0.72 to 0.48; very low certainty).

• Efficacy of Probiotic Consumption on Oral Outcomes in Children and/or Adolescents: A Meta-Analysis. 2024 All outcomes

  follow-up: mean 1.1 months · Healthy children and/or adolescents (<18 years) without systemic disease; RCTs from multiple countries (India, Thailand, Spain, Australia, New Zealand, Sweden, Poland, Colombia, Saudi Arabia); mostly school/community and clinic settings · Overall (all presentations pooled)
  MD -0.12 [-0.72, 0.48]
  3 studies · 137 participants
  Very low

Teledentistry (index test): dental caries diagnosis from photographs taken with DSLR or smartphone cameras; store-and-forward vs Visual or clinical examination

Across 13 studies, the sensitivity of teledentistry (photographic) caries diagnosis versus visual examination ranged from 48% to 98.3%; the review pooled no estimate and did not grade certainty.

• Teledentistry accuracy for caries diagnosis: a systematic review of in-vivo studies using extra-oral photography… 2024 All outcomes

  Cross-sectional diagnostic accuracy (index test vs reference standard, in-vivo) · In-vivo: dental clinics/hospitals, schools, and a juvenile detention facility (11 countries) · Overall (studies reporting sensitivity; narrative synthesis)
  Sensitivity Overall 48% to 98.3% across 13 studies; sensitivity is lesion-stage dependent: Kohara reported <40% for initial/moderate caries (75-100% for extensive) and early enamel lesions were less sensitive
  13 studies
  GRADE not reported

Probiotics vs placebo or control

Probiotics probably make little to no difference to the number of dental caries versus control (MD -0.24 carious pieces, 95%CI -0.72 to 0.23; low certainty).

• Efficacy of Probiotic Consumption on Oral Outcomes in Children and/or Adolescents: A Meta-Analysis. 2024 All outcomes

  follow-up: mean 26 months · Healthy children and/or adolescents (<18 years) without systemic disease; RCTs from multiple countries (India, Thailand, Spain, Australia, New Zealand, Sweden, Poland, Colombia, Saudi Arabia); mostly school/community and clinic settings · Overall (all presentations pooled)
  MD -0.24 [-0.72, 0.23]
  6 studies · 1049 participants
  Low

Teledentistry (index test): dental caries diagnosis from photographs taken with DSLR or smartphone cameras; store-and-forward vs Visual or clinical examination

Inter-examiner reliability ranged from kappa 0.44 to 0.91 across 13 studies (moderate to almost perfect agreement); certainty not graded.

• Teledentistry accuracy for caries diagnosis: a systematic review of in-vivo studies using extra-oral photography… 2024 All outcomes

  Cross-sectional diagnostic accuracy (index test vs reference standard, in-vivo) · In-vivo: dental clinics/hospitals, schools, and a juvenile detention facility (11 countries) · Overall (studies reporting inter-examiner reliability; narrative synthesis)
  Inter-examiner reliability (kappa) reported in 13 studies, ranging from 0.44 to 0.91. No pooled estimate.
  13 studies
  GRADE not reported

Teledentistry (index test): dental caries diagnosis from photographs taken with DSLR or smartphone cameras; store-and-forward vs Visual or clinical examination

Negative predictive value was reported in 10 studies and ranged widely across studies (about 31% to 99.5%); no pooled estimate and certainty not graded.

• Teledentistry accuracy for caries diagnosis: a systematic review of in-vivo studies using extra-oral photography… 2024 All outcomes

  Cross-sectional diagnostic accuracy (index test vs reference standard, in-vivo) · In-vivo: dental clinics/hospitals, schools, and a juvenile detention facility (11 countries) · Overall (studies reporting NPV; narrative synthesis)
  Negative predictive value reported in 10 of 19 studies; per-study values ranged from about 31% to 99.5% (Table 2). No pooled estimate.
  10 studies
  GRADE not reported

Probiotics vs placebo or control

Probiotics probably reduce Streptococcus mutans count versus control (MD -0.40 CFU/mL, 95%CI -0.57 to -0.24; moderate certainty).

• Efficacy of Probiotic Consumption on Oral Outcomes in Children and/or Adolescents: A Meta-Analysis. 2024 All outcomes

  follow-up: mean 4.4 months · Healthy children and/or adolescents (<18 years) without systemic disease; RCTs from multiple countries (India, Thailand, Spain, Australia, New Zealand, Sweden, Poland, Colombia, Saudi Arabia); mostly school/community and clinic settings · Overall (all presentations pooled)
  MD -0.40 [-0.57, -0.24]
  11 studies · 1321 participants
  Moderate

Probiotics vs placebo or control

Only one trial (Borrell 2021) reported the bleeding index, showing slightly more bleeding with probiotics (MD 0.10, 95%CI 0.02 to 0.18); not pooled or GRADE-rated.

• Efficacy of Probiotic Consumption on Oral Outcomes in Children and/or Adolescents: A Meta-Analysis. 2024 All outcomes

  1.5 months · Healthy children and/or adolescents (<18 years) without systemic disease; RCTs from multiple countries (India, Thailand, Spain, Australia, New Zealand, Sweden, Poland, Colombia, Saudi Arabia); mostly school/community and clinic settings · Single study (Borrell 2021); not pooled
  MD 0.10 [0.02, 0.18]
  1 study · 27 participants
  GRADE not reported

Disability (developmental, intellectual, or sensory) vs Not applicable (single-group prevalence)

Gingival inflammation is common among persons with disabilities in Saudi Arabia (moderate-to-severe up to about 60%), reported narratively without a pooled comparative estimate (ungraded).

• Disabilities and Disparities in Oral Health-Related Quality of Life: A Systematic Review and Meta-Analysis in Saudi… 2024 All outcomes

  Cross-sectional · Hearing-impairment and cerebral-palsy clinical settings in Saudi Arabia (Riyadh)
  Narrative synthesis (no pooled estimate). Moderate-to-severe gingival inflammation up to about 60% among PWDs (abstract). Alkahtani 2019 (hearing-impaired adults, single-arm): 60.1% had moderate gingival inflammation…
  Studies not reported
  GRADE not reported

Probiotics vs placebo or control

Probiotics may make little to no difference to the bacterial plaque index versus control (MD 0.21, 95%CI -0.55 to 0.96; very low certainty).

• Efficacy of Probiotic Consumption on Oral Outcomes in Children and/or Adolescents: A Meta-Analysis. 2024 All outcomes

  follow-up: mean 2.3 months · Healthy children and/or adolescents (<18 years) without systemic disease; RCTs from multiple countries (India, Thailand, Spain, Australia, New Zealand, Sweden, Poland, Colombia, Saudi Arabia); mostly school/community and clinic settings · Overall (all presentations pooled)
  MD 0.21 [-0.55, 0.96]
  4 studies · 171 participants
  Very low