Teeth and gums
Everything in the library studied for it, medical and holistic together. Within each kind, what was shown to help comes first, strongest evidence first. What was tested and not shown to help stays on the list.
Strong several reviews agree · Moderate one review or consistent trials · Limited one or a few small studies · Untested no study in people, listed with what it rests on
Medication
Cavities: fluoride toothpaste
Shown to prevent about 24% of new cavities in children against non-fluoride toothpaste, more with higher fluoride concentration and supervised brushing.
The numbers and sources
- Effect
- Across 70 trials (42,300 children), fluoride toothpaste prevented 24% of new decayed, missing and filled surfaces against non-fluoride toothpaste (prevented fraction 24%, 95% CI 21 to 28%). The effect was larger with higher baseline decay, higher fluoride concentration, more frequent use and supervised brushing, and did not change with water fluoridation [1]. A 2019 update of 96 studies found 1,000 to 1,250 ppm toothpaste lowered caries increments in children and adolescents (SMD -0.28, 95% CI -0.32 to -0.25, 55 studies) and 1,450 to 1,500 ppm lowered them more (SMD -0.36, 95% CI -0.43 to -0.29). In young children's baby teeth, 1,500 ppm toothpaste lowered decayed and filled surfaces by 1.86 (95% CI -2.51 to -1.21, 1 study, 998 children). In adults, 1,000 or 1,100 ppm toothpaste lowered decayed, missing and filled surfaces by 0.53 (95% CI -1.02 to -0.04, 3 studies, 2,162 adults) [2].
- Population
- Children up to 16 in 74 trials [1]. Children, adolescents and adults in 96 trials published 1955 to 2014, most followed for 36 months [2].
- Sources
- [1], [2]
- Caveats
- Heterogeneity was clear in the 2003 review [1]. Most comparisons between concentrations were low certainty, and evidence in adults came from 3 studies [2]. Soft tissue damage and tooth staining were minimal where reported, and only a minority of studies assessed adverse effects [2].
Cavities: fluoride varnish
Shown to prevent about 43% of new cavities in permanent teeth. A preschool review found 12% fewer, with estimates not significant once prediction intervals were considered.
The numbers and sources
- Effect
- Across 13 trials in permanent teeth, fluoride varnish prevented 43% of new decayed, missing and filled surfaces against placebo or no treatment (95% CI 30% to 57%). Across 10 trials in baby teeth, it prevented 37% (95% CI 24% to 51%) [3]. A review of 20 trials in preschool children found a smaller effect: the risk of new cavities was 12% lower (RR 0.88, 95% CI 0.81 to 0.95), so about 17 children would need varnish for one to avoid new cavities where half develop them. Once prediction intervals were considered, none of the pooled estimates was significant [4].
- Population
- 22 trials with 12,455 children and adolescents [3]. Preschool children in 20 trials, 17 pooled [4].
- Sources
- [3], [4]
- Caveats
- The Cochrane review included mainly high risk of bias trials, with I² of 75% in permanent teeth [3]. Only one preschool trial had low risk of bias in all domains [4]. The two reviews differ in the size of the effect in young children.
Cavities: fluoride mouthrinse
Shown to prevent about 27% of new cavities in permanent teeth with supervised school rinsing in children and adolescents.
The numbers and sources
- Effect
- Across 35 trials (15,305 children and adolescents), supervised fluoride mouthrinse prevented 27% of new decayed, missing and filled permanent tooth surfaces (95% CI 23% to 30%, I² 42%, moderate quality). The figure for whole teeth was 23% (95% CI 18% to 29%, 13 trials). Baseline decay, background fluoride, rinsing frequency and concentration did not change the effect [5].
- Population
- 37 trials with 15,813 children and adolescents, almost all rinsing with sodium fluoride under supervision in schools [5].
- Sources
- [5]
- Caveats
- 28 of 37 trials were at high risk of bias. Adverse effects were rarely reported. Most evidence comes from supervised school programs, and the effect of home use is less clear [5].
Cavities: fluoride supplements (tablets, drops, lozenges)
Limited evidence: supplements lowered cavities in permanent teeth about 24% against none, with unclear results in baby teeth and no gain over topical fluoride.
The numbers and sources
- Effect
- In 3 studies comparing supplements with no supplement, permanent teeth had 24% fewer decayed, missing and filled surfaces (95% CI 16 to 33%). The effect on baby teeth was unclear: one study found no effect and another found a large reduction. Against topical fluorides or other prevention, supplements showed no difference in either set of teeth [6]. A second review found weak and inconsistent evidence for baby teeth, and found reductions in permanent teeth of older children. One trial of 3 to 6 year olds found a 43.0% difference and another found no significant benefit [7].
- Population
- 11 studies with 7,196 children [6]. 12 trials reported in 20 papers [7].
- Sources
- [6], [7]
- Caveats
- 10 of 11 trials were at unclear risk of bias and 1 at high risk, and the Cochrane authors call the evidence weak [6]. Fifteen reports had withdrawal rates of 30% or more [7].
Enamel erosion: stannous fluoride toothpaste
Limited evidence: stannous fluoride toothpaste reduced erosive wear more than sodium fluoride in lab tests, but not in enamel samples worn in the mouth.
The numbers and sources
- Effect
- Across 8 laboratory and in situ studies, stannous fluoride toothpaste reduced erosive tooth wear more than sodium fluoride toothpaste in vitro (effect size -6.80, 95% CI -13.42 to -0.19). In situ studies, in which volunteers wear enamel samples in the mouth, did not show a significant difference [10].
- Population
- In vitro and in situ enamel samples [10].
- Sources
- [10]
- Caveats
- No clinical trials were included. The authors call the evidence insufficient for firm conclusions [10].
White spots during braces
Not shown to lower white spots with fluoride varnish during braces. Single studies found fewer with fluoride foam or 5,000 ppm toothpaste.
The numbers and sources
- Effect
- Professionally applied varnish of 7,700 or 10,000 ppm every 6 weeks did not clearly lower new white spot lesions against non-fluoride placebo (RR 0.52, 95% CI 0.14 to 1.93, 2 studies, 405 participants, low certainty). In single studies, fluoride foam of 12,300 ppm every 2 months cut new lesions from 49% to 12% (RR 0.26, 95% CI 0.11 to 0.57, 95 participants), and 5,000 ppm toothpaste lowered them from 27% to 18% against 1,450 ppm toothpaste (RR 0.68, 95% CI 0.46 to 1.00, 380 participants). A 250 ppm rinse did not differ from placebo [9].
- Population
- Patients with fixed braces in 10 studies, 1,798 randomized [9].
- Sources
- [9]
- Caveats
- Each positive comparison rests on one study at unclear risk of bias, and none has been repeated [9].
Fluoride tablets in pregnancy and children's cavities
One trial found fluoride tablets late in pregnancy did not change the share of children with cavities at ages 3 or 5.
The numbers and sources
- Effect
- In one trial, fluoride tablets in the last 6 months of pregnancy did not change the share of children with cavities at age 3 (RR 1.46, 95% CI 0.75 to 2.85, 938 children) or age 5 (RR 0.84, 95% CI 0.53 to 1.33, 798 children). Fluorosis at age 5 was similar in both groups [8].
- Population
- One randomized trial of pregnant women and their children [8].
- Sources
- [8]
- Caveats
- Very low quality evidence from a single trial [8].
Supplements
Pain after wisdom tooth surgery
Shown to lower pain after wisdom tooth surgery in adults, though reviews of the same small trials disagree on when the effect appears.
The numbers and sources
- Effect
- In 6 RCTs against placebo, bromelain lowered pain 7 days after surgery (SMD -0.54, 95% CI -0.87 to -0.20) but not in the first 2 to 3 days [1]. A second meta-analysis of 4 studies found lower pain (MD -0.38, 95% CI -0.66 to -0.09) [2]. A third, of 5 trials (252 patients), found lower pain at 48 to 72 hours (MD -0.89, 95% CI -1.70 to -0.09) [3]. A fourth, of 6 RCTs, found lower pain in the first 24 hours (SMD -0.49, 95% CI -0.82 to -0.17) and at 7 days (SMD -0.52), with better ratings of appearance, social isolation and sleep in the first week [4].
- Population
- Adults having lower third molar surgery [1][2][3][4].
- Sources
- [1], [2], [3], [4]
- Caveats
- The four reviews drew largely on the same small trials. Timing of the pain effect differs between them.
Periodontitis, added to dental treatment
Shown to reduce gum pocket depth and improve attachment by about 0.5 mm when added to scaling and root planing in adults with periodontitis.
The numbers and sources
- Effect
- Across 15 RCTs (617 patients), omega-3 added to scaling and root planing reduced probing pocket depth by 0.43 mm more (95% CI -0.68 to -0.18, I² 92%) and improved clinical attachment level by 0.47 mm more (95% CI -0.76 to -0.18, 12 RCTs) than scaling alone or with placebo. Gingival index (SMD -0.59), bleeding on probing (SMD -0.95) and plaque index (SMD -0.34) also improved [20]. A review of 21 studies found attachment gain 0.54 mm greater (95% CI 0.36 to 0.72) and pocket depth 0.57 mm lower (95% CI 0.4 to 0.74), with larger effects at 6 to 12 months [21]. A third review of 16 RCTs, some adding aspirin, found attachment 0.49 mm better (95% CI -0.75 to -0.23) and pocket depth 0.44 mm lower at 3 months, and 0.58 mm and 0.45 mm at 6 months [22].
- Population
- Adults with periodontitis receiving nonsurgical periodontal therapy [20][21][22].
- Sources
- [20], [21], [22]
- Caveats
- Certainty of evidence was very low to low [20] and moderate to low [21], and heterogeneity was very high in both. The reviews overlap in the trials they include. The differences are fractions of a millimeter. This is omega-3 alongside scaling and root planing, not instead of it.
Tooth sensitivity: arginine toothpaste (topical)
Arginine toothpaste was shown to ease tooth sensitivity more than other desensitizing toothpastes at 4 and 8 weeks in adults, with no difference beyond 12 weeks.
The numbers and sources
- Effect
- Across 18 RCTs (1,423 patients), arginine toothpaste improved touch sensitivity (SMD 1.95, 95% CI 1.14 to 2.76) and air-blast sensitivity (SMD -1.60, 95% CI -2.14 to -1.05) at 4 weeks against toothpastes with other desensitizing ingredients, and both again at 8 weeks (SMD 2.01 and -1.41). Air-blast scores did not differ at days 0 and 3 or week 2, and neither test differed beyond 12 weeks [4]. Across 14 RCTs, arginine toothpaste reduced sensitivity more than placebo, potassium and strontium toothpastes, reported as p values below 0.05 [5]. A third review found a potential role from small trials without medium or long-term follow-up [6].
- Population
- Adults with dentin hypersensitivity in RCTs [4][5][6].
- Sources
- [4], [5], [6]
- Caveats
- This is toothpaste applied to the teeth, not oral arginine. GRADE quality was moderate against placebo and potassium and low against strontium [5]. Samples were small [6].
Bleeding gums
Shown to lower gum bleeding in mostly healthy people, most in those with low vitamin C levels, and only slightly when levels were already high.
The numbers and sources
- Effect
- Across 15 trials (1,140 mostly healthy participants), vitamin C lowered gingival bleeding tendency when estimated baseline plasma vitamin C was below 28 µmol/L (SMD -0.83, 95% CI -1.16 to -0.49). When baseline levels were above 48 µmol/L the effect was small (SMD -0.23, 95% CI -0.45 to -0.01), and when unknown it was not significant (SMD -0.56, 95% CI -1.19 to 0.06) [7]. A systematic review of 6 RCTs found vitamin C improved bleeding indices in gingivitis [8]. In 136 children aged 8 to 16 given scaling and oral hygiene instruction, adding vitamins C and D for 8 weeks gave a lower percentage of bleeding sites at 4 and 8 weeks, after adjusting for a higher starting level in that group [9].
- Population
- 1,140 mostly healthy participants in 6 countries [7]; adults in RCTs of periodontal therapy [8]; school children in Pakistan [9].
- Sources
- [7], [8], [9]
- Caveats
- The effect depended on starting vitamin C status [7]. The children's trial combined vitamins C and D, had no placebo, and its groups differed at baseline [9].
Cavities in children
Shown to lower new cavities about half in children in older trials, rated low certainty. Vitamin D in pregnancy did not change cavities in one trial.
The numbers and sources
- Effect
- Across 24 controlled clinical trials (2,827 children), vitamin D given as D2, D3 or ultraviolet light lowered the rate of new cavities (relative rate 0.53, 95% CI 0.43 to 0.65), with no robust difference between the forms [43]. A 2024 Cochrane review found one trial of high-dose against low-dose vitamin D in pregnancy, with no clear difference in cavities in the children's baby teeth (RR 0.99, 95% CI 0.70 to 1.41, 496 children, very low certainty) [44]. In that trial, 2,400 IU a day from week 24 of pregnancy, on top of 400 IU standard care, was not associated with cavities at age 6 [45].
- Population
- Children in controlled trials, 22 of the 24 predating modern trial design [43]. Children of women in the COPSAC2010 pregnancy trial in Copenhagen [44][45].
- Sources
- [43], [44], [45]
- Caveats
- The older trials showed significant heterogeneity and publication bias, and the author rates the conclusion low certainty [43]. The newer finding comes from one pregnancy trial [44][45].
Tooth loss and cavities
Limited evidence: secondary analyses found fewer older adults lost teeth on calcium with vitamin D, and fewer children had cavities when mothers took calcium in pregnancy.
The numbers and sources
- Effect
- In 145 adults aged 65 and older who finished a 3-year trial of calcium with vitamin D against placebo for bone loss, 13% (11 of 82) on supplements and 27% (17 of 63) on placebo lost one or more teeth during the trial (OR 0.4, 95% CI 0.2 to 0.9) [12]. Among 195 children aged 12 whose mothers took calcium or placebo in pregnancy, 63.3% in the calcium group and 86.6% in the placebo group had at least one decayed, missing or filled tooth (RR 0.73, 95% CI 0.62 to 0.87) [13].
- Population
- Healthy adults aged 65 and older [12]. A random sample of children from a trial of 614 pregnant women at one hospital in Rosario, Argentina [13].
- Sources
- [12], [13]
- Caveats
- Both are secondary analyses of trials designed for other outcomes. The older adults took calcium together with vitamin D, so calcium alone was not tested [12]. Only 195 of the trial's children were examined [13].
Enamel defects in children after vitamin D in pregnancy
One trial found about half as many enamel defects at age 6 in children of women given vitamin D in pregnancy, in an after-the-fact analysis.
The numbers and sources
- Effect
- Children of women given 2,400 IU a day of vitamin D3 from week 24 of pregnancy to 1 week after birth, on top of 400 IU standard care, had fewer enamel defects in permanent teeth at age 6 than children of women on placebo (15.1% against 27.5%, OR 0.47, 95% CI 0.27 to 0.81). The same held for baby teeth (8.6% against 15.9%, OR 0.50, 95% CI 0.28 to 0.87). Cavities did not differ [45].
- Population
- 623 pregnant women in Copenhagen and 496 of their children examined at age 6 [45].
- Sources
- [45]
- Caveats
- A post hoc analysis of one trial designed for other outcomes [45].
Periodontitis, oral CoQ10 added to dental treatment
Mixed results: one review found slightly shallower gum pockets with 120 mg a day added to dental cleaning, while others found no clear effect.
The numbers and sources
- Effect
- In a systematic review of 10 RCTs, the six oral trials of 120 mg a day alongside scaling and root planing found probing depth 0.41 mm lower (95% CI 0.02 to 0.80) and clinical attachment gain 0.52 mm greater (95% CI 0.26 to 0.78) than controls after 12 weeks [16]. A 2023 review of 5 systemic and 12 local CoQ10 RCTs found heterogeneous protocols, low reporting quality and high or unclear risk of bias. About half the trials reported group differences in pocket depth, and the authors concluded no statement on effectiveness was possible [17]. An umbrella meta-analysis of 14 meta-analyses of antioxidants, CoQ10 among them, found no significant pooled change in probing depth (ES 0.064, 95% CI -0.341 to 0.468) or attachment level, and less bleeding on probing (ES 0.57, 95% CI 0.44 to 0.69) [18].
- Population
- Adults with periodontitis receiving nonsurgical periodontal therapy [16][17]; meta-analyses of human studies [18].
- Sources
- [16], [17], [18]
- Caveats
- Certainty was very low [16]. The reviews disagree, and the umbrella review pooled several antioxidants, so it does not isolate CoQ10 [18].
Periodontitis, CoQ10 gel in the gums (topical)
Mixed results: one review found less plaque, bleeding and pocket depth with CoQ10 gel, while a later review of 4 trials found no effect.
The numbers and sources
- Effect
- Across 11 trials, CoQ10 lowered plaque index (SMD -0.64, 95% CI -1.03 to -0.26), bleeding index (SMD -1.05), pocket depth (SMD -0.96, 95% CI -1.35 to -0.58), clinical attachment level (SMD -0.73) and gingival index (SMD -0.63). Effects were stronger when placed in the gum pocket than on the gum surface [19]. In a 2025 review, four trials of local CoQ10 (one topical, three in the pocket) showed no significant effect on probing depth or attachment gain [16].
- Population
- Adults with periodontitis in controlled trials [19][16].
- Sources
- [19], [16]
- Caveats
- Heterogeneity was high (I² 72.8% to 89.5%), and studies at high risk of bias reported larger effects than studies at unclear risk [19]. The two reviews disagree.
Cavities: arginine toothpaste (topical)
Mixed results: one review found arginine toothpaste with fluoride lowered early cavities, and another found the evidence insufficient.
The numbers and sources
- Effect
- Sources disagree. A meta-analysis of 7 studies found that arginine with fluoride lowered early coronal and root cavities more than placebo or fluoride alone, and the abstract reports no effect sizes [8]. A second review found the evidence insufficient for a cavity-preventing effect of adding arginine to toothpaste. It drew no conclusions on children's studies because of conflicts of interest, and noted that control children in several studies used non-fluoride toothpaste [9].
- Population
- 10 studies with 15,546 participants [8]. RCTs in children, adults and older adults [9].
- Sources
- [8], [9]
- Caveats
- This is toothpaste applied to the teeth, not oral arginine. The first review downgraded its evidence for risk of bias and possible publication bias, and called for trials not supported by industry [8].
Swelling after wisdom tooth surgery
Limited evidence: reviews of overlapping trials disagree, with two finding less swelling after wisdom tooth surgery and two finding no effect.
The numbers and sources
- Effect
- One meta-analysis found less facial swelling early (SMD -0.24, 95% CI -0.46 to -0.02) and late (SMD -0.54, 95% CI -0.84 to -0.24) after surgery [1]. Another found less edema (MD -0.34, 95% CI -0.68 to -0.01) [2]. Two others found no significant effect on swelling [3][4].
- Population
- Adults having lower third molar surgery [1][2][3][4].
- Sources
- [1], [2], [3], [4]
- Caveats
- Reviews of overlapping trials reached opposite results.
Periodontitis, added to dental treatment
Not shown to improve gum pocket depth or attachment when added to periodontal treatment in adults with periodontitis.
The numbers and sources
- Effect
- In a systematic review of 6 RCTs, vitamin C added to nonsurgical periodontal therapy did not significantly reduce probing depth or increase clinical attachment at 3 months [8].
- Population
- Adults 18 and older with periodontitis [8].
- Sources
- [8]
- Caveats
- Six trials, assessed with a quality appraisal tool and not pooled. The authors describe the evidence as limited [8].
Periodontitis alongside gum treatment
Not shown to change gum pocket depth when added to periodontal treatment in adults. One review found more benefit in people with low vitamin D.
The numbers and sources
- Effect
- In 3 studies that added vitamin D to non-surgical periodontal therapy, pocket depth did not change (MD 0.0023 mm, 95% CI -0.0378 to 0.0424) [46]. A review of 4 RCTs found limited added benefit in people with sufficient vitamin D, and greater pocket depth reduction, attachment gain and lower plaque and bleeding scores in deficient people whose levels were raised above 30 ng/mL [47].
- Population
- 13 RCTs and 1 controlled trial, 3 of them pooled [46]. Adults with periodontitis in 4 RCTs [47].
- Sources
- [46], [47]
- Caveats
- Evidence was limited and heterogeneous [46]. The second review did not pool results [47].
Practices
Oral health, energy and immunity
Not studied in people. Social media videos credit mouth taping with better sleep and oral health, and with more energy and immunity.
No study in people. This rests on what users report.
The numbers and sources
- Effect
- A review of TikTok videos about mouth taping found the most common proposed advantages were improved sleep and oral health. The same review reports claims of increased energy, immunity and dental health, and found few of them had been evaluated [5].
- Population
- The first 50 TikTok videos meeting the review's criteria [5].
- Sources
- [5]
- Caveats
- Claims in videos are not measurements. No study located tested mouth taping for oral health, dental health, energy or immunity.