What do systematic reviews say?

Ozone applied to the carious lesion (10 or 40 seconds), with a fluoride reductant and oral hygiene/preventive advice vs No ozone, with a fluoride reductant and oral hygiene/preventive advice (as in the intervention group)

• Ozone therapy for the treatment of dental caries 2004 · Cochrane All outcomes

  To 6 months
  Baysan 2003 stated that no adverse events were reported to 6 months; no information was provided by Abu-Naba'a 2003 or Abu-Naba'a 2003pilot.
  1 study
  GRADE not reported

Primary school-based behavioural intervention (both oral hygiene and dietary components) vs No treatment (or delayed treatment)

The review found no eligible studies for this question.

• Primary school‐based behavioural interventions for preventing caries 2013 · Cochrane All outcomes
  No study reported any adverse events.
  0 studies
  No studies found

Package of oral health education/promotion including oral hygiene advice for pregnant women, mothers, infants and young children, plus dietary and feeding practice advice for infants and young children vs usual care

• Interventions with pregnant women, new mothers and other primary caregivers for preventing early childhood caries 2024 · Cochrane All outcomes
  One trial (Harrison 2012) reported observing no adverse events; other trials provided no information on adverse events.
  1 study
  GRADE not reported

Micro-invasive treatment (proximal sealing or resin infiltration): resin sealant, glass ionomer sealant, polyurethane/adhesive patch, or resin infiltration vs Non-invasive / control treatment

• Micro‐invasive interventions for managing proximal dental decay in primary and permanent teeth 2015 · Cochrane All outcomes

  1 to 3 years
  The four studies that measured adverse events reported no adverse events after micro-invasive treatment (no events in either arm)
  4 studies
  GRADE not reported

Elective neck dissection (at time of primary tumour resection) vs Therapeutic (delayed) neck dissection

Elective neck dissection (at time of primary tumour resection) probably leads to higher adverse events associated with treatment compared with therapeutic (delayed) neck dissection (moderate certainty).

• Interventions for the treatment of oral cavity and oropharyngeal cancers: surgical treatment 2023 · Cochrane All outcomes
  RR 1.31 [1.11, 1.54]
  2 studies · 746 participants
  Moderate

Sentinel node biopsy (neck dissection only if biopsy positive) vs Elective neck dissection

• Interventions for the treatment of oral cavity and oropharyngeal cancers: surgical treatment 2023 · Cochrane All outcomes
  Adverse events: no adverse events were reported (Garrel 2020).
  1 study · 279 participants
  Very low

Elective radical (comprehensive) neck dissection vs Elective selective neck dissection

• Interventions for the treatment of oral cavity and oropharyngeal cancers: surgical treatment 2023 · Cochrane All outcomes
  Adverse events (BHNCSG 1998): flap necrosis, wound infection, fistula, vascular rupture, haematoma, seroma, chyle fistula; no complications in 45/76 modified radical ND and 54/72 supraomohyoid ND; 2 vs 1 postoperative…
  1 study · 148 participants
  Low

Surgery plus radiotherapy vs Chemotherapy (chemoradiotherapy)

The review found no eligible studies for this question.

• Interventions for the treatment of oral cavity and oropharyngeal cancers: surgical treatment 2023 · Cochrane All outcomes
  Adverse events: not reported for any participants (Iyer 2015).
  0 studies
  No studies found

Superselective neck dissection vs Elective selective neck dissection

• Interventions for the treatment of oral cavity and oropharyngeal cancers: surgical treatment 2023 · Cochrane All outcomes
  Adverse events: no adverse events reported; 72 participants (2 RCTs).
  2 studies · 72 participants
  Very low

Supraomohyoid neck dissection vs Modified radical neck dissection

• Interventions for the treatment of oral cavity and oropharyngeal cancers: surgical treatment 2023 · Cochrane All outcomes
  Adverse events: significant difference in complication rates, lower for supraomohyoid (SOND 13.0% vs MRND 21.9%, P=0.040). UW-QOL at 1 year: supraomohyoid superior in pain relief (78.8% vs 75.2%, P=0.013) and shoulder…
  1 study · 332 participants
  Very low

Surgery plus radiotherapy vs Radiotherapy alone

• Interventions for the treatment of oral cavity and oropharyngeal cancers: surgical treatment 2023 · Cochrane All outcomes
  Adverse events: severe acute effects in both groups (subcutaneous fibrosis, telangiectasia, moderate-to-severe oedema, xerostomia, trismus, dysphagia); subcutaneous fibrosis more prevalent with surgery + radiotherapy…
  1 study · 35 participants
  Very low

PET-CT following chemoradiotherapy (neck dissection only if no/incomplete response) vs Planned neck dissection before or after chemoradiotherapy

• Interventions for the treatment of oral cavity and oropharyngeal cancers: surgical treatment 2023 · Cochrane All outcomes
  Adverse events: 22 surgical complications in the PET-CT group vs 83 in the planned-surgery group (Mehanna 2017).
  1 study · 564 participants
  Very low

Intervention not reported

• A Systematic Review and Meta-Analysis of the Role of Sugar-Free Chewing Gum on Plaque Quantity in the Oral Cavity. 2022 All outcomes
  No adverse events reported
  8 studies
  GRADE not reported

Microinvasive techniques (resin infiltration, resin/GIC sealant, or glass ionomer varnish) vs Non-invasive measures (fluoride varnish/toothpaste, flossing, oral hygiene instruction, sham/standard of care)

Only three trials reported secondary/adverse outcomes; no adverse events were attributed to microinvasive treatment and periodontal findings were mixed and not pooled (ungraded).

• Microinvasive interventions in the management of proximal caries lesions in primary and permanent teeth- systematic… 2025 All outcomes

  Baseline and follow-up · Multiple countries (Brazil, Saudi Arabia, Netherlands, USA, Turkey, Switzerland, Germany, New Zealand, Chile, Thailand); dental clinic/community settings
  Reported narratively by 3 trials (Arthur 2018, Sarti 2020, Jorge 2019). No adverse events were attributed to microinvasive treatment. Gingival bleeding index: no significant difference in Arthur 2018 and Jorge 2019 but…
  3 studies
  GRADE not reported

Surgery vs Radiotherapy alone

• Interventions for the treatment of oral cavity and oropharyngeal cancers: surgical treatment 2023 · Cochrane All outcomes
  Adverse events: grade 2+ treatment-related events similar (31/34 radiotherapy vs 33/34 surgery; RR 0.94, 0.83 to 1.06); more hearing loss/neutropenia/constipation/tinnitus with radiotherapy, more oral bleeding/trismus…
  1 study · 68 participants
  Very low