The grades in this post: Strong means good randomised trials agree. Mixed means the trials are few, small or conflicting. Mechanistic means the biology makes sense but hasn’t been shown to change outcomes in people. None means there’s no usable evidence. Observational studies are labelled as such: they show a link, not proof of cause.
How often implants fail
In 107 studies pooled in one review, about 3% of implants in non-smokers failed (1,923 of 60,464) and about 6% in smokers (1,259 of 19,836) (Chrcanovic 2015). Failure rates vary with the study, the site and how long people are followed. Observational, large.
What changes the odds, graded
Smoking: the clearest risk you can change
- A review of 292 publications (over 150,000 implants) found implants in smokers had about 2.4 times the odds of failing (OR 2.40). Smokers also lost slightly more bone around the implant, about 0.6 mm on average (Mustapha 2022).
- Observational, large and consistent. The authors of the earlier review warn that the studies didn’t control for other factors, so the figures should be read with caution (Chrcanovic 2015).
- Stopping smoking is the most useful single change. Your dentist or GP can help.
Vitamin D: a link, not yet a proven fix
- Reviews disagree. One, of six human studies, found the results inconsistent (Alsulaimani 2022). One, of four studies, found slightly more bone loss around the implant with lower vitamin D, but couldn’t say whether more implants failed (Bazal-Bonelli 2022). The largest, of 27 human studies (ten looking back at records, three randomised) plus animal studies, found low vitamin D went with up to four times more early failures, and recommends checking and correcting deficiency before surgery (Miron 2025).
- A 2022 review made up mostly of animal studies (13 animal studies, two clinical studies and three case reports) called the evidence that people benefit from vitamin D supplements “slight” (Werny 2022).
- Observational, mixed; trials are few.
- My reading: checking vitamin D before an implant and correcting a deficiency is reasonable and cheap. Whether it prevents failure in someone who isn’t deficient hasn’t been shown.
- UK deficiency cut-off: 25 nmol/L (10 ng/mL) (SACN 2016). My working range: 75–125 nmol/L (30–50 ng/mL), a clinical target, not official guidance.
Gum disease, blood sugar and medicines
- Gum disease. The 2017 World Workshop on periodontal and peri-implant diseases found strong evidence that a history of gum disease (periodontitis), poor plaque control and no regular check-ups after treatment raise the risk of inflammation and bone loss around implants, called peri-implantitis (Schwarz 2018). Consensus It found the evidence for smoking and diabetes as causes of peri-implantitis inconclusive.
- Diabetes. A 2022 review of 89 publications found implants in people with diabetes had about 1.8 times the odds of failing (Al Ansari 2022). An earlier review of 14 publications found no clear difference (Chrcanovic 2014). Observational, mixed. Neither tells you how much better control lowers the risk.
- Bisphosphonates (bone-strengthening medicines). A 2023 review of 33 publications found implants in people taking them had about 1.65 times the odds of failing (Sulaiman 2023). Observational, with relatively few implants in people taking the drugs (1,727). Don’t stop a bone medicine on your own; ask the prescriber.
- These are recognised risks your dentist will ask about.
Zinc, magnesium, vitamin K2, vitamin C
- All play parts in bone and collagen biology.
- No trial checked here shows that supplementing any of them changes implant success. Mechanistic
Probiotics and the oral microbiome
- There’s research interest in probiotic strains for gum inflammation. I haven’t graded it here, and no claim is made about implant success.
What I’d do before an implant
- If you smoke, this is the time to stop.
- Get your gums treated first if your dentist finds gum disease, and keep up the check-ups afterwards.
- If you have diabetes, aim for good control before the procedure, with your GP or diabetes team.
- Ask for a vitamin D check, especially in winter, and correct a deficiency.
- Tell your dentist about every medicine and supplement.
- Eat well. If you’ve lost weight without trying or are eating little, say so.
How strong is the evidence?
| Claim | Grade | Main source |
|---|---|---|
| Smoking raises implant failure | Observational, large, consistent | Chrcanovic 2015; Mustapha 2022 |
| A history of gum disease raises the risk of peri-implantitis | Consensus strong evidence, per the 2017 workshop | Schwarz 2018 |
| Diabetes raises implant failure | Observational, mixed | Al Ansari 2022; Chrcanovic 2014 |
| Bisphosphonates raise implant failure | Observational, small numbers on the drugs | Sulaiman 2023 |
| Low vitamin D goes with more early failures | Observational, mixed | Miron 2025; Alsulaimani 2022; Bazal-Bonelli 2022 |
| Vitamin D supplements prevent failure | Mixed few trials | Werny 2022; Miron 2025 |
| Zinc, magnesium, K2 or vitamin C supplements improve implant success | None found | — |
Sources
- Al Ansari Y et al. Diabetes mellitus and dental implants: a systematic review and meta-analysis. Materials (Basel) 2022;15:3227. PMID 35591561. doi:10.3390/ma15093227
- Alsulaimani L et al. The relationship between low serum vitamin D level and early dental implant failure: a systematic review. Cureus 2022;14:e21264. PMID 35178319. doi:10.7759/cureus.21264
- Bazal-Bonelli S et al. Influence of serum vitamin D levels on survival rate and marginal bone loss in dental implants: a systematic review. Int J Environ Res Public Health 2022;19:10120. PMID 36011753. doi:10.3390/ijerph191610120
- Chrcanovic BR et al. Diabetes and oral implant failure: a systematic review. J Dent Res 2014;93:859–67. PMID 24928096. doi:10.1177/0022034514538820
- Chrcanovic BR et al. Smoking and dental implants: a systematic review and meta-analysis. J Dent 2015;43:487–98. PMID 25778741. doi:10.1016/j.jdent.2015.03.003
- Miron RJ et al. Relationship between vitamin D deficiency and early implant failure and osseointegration. Periodontol 2000 2025 (online 30 October). PMID 41163589. doi:10.1111/prd.70017
- Mustapha AD et al. Smoking and dental implants: a systematic review and meta-analysis. Medicina (Kaunas) 2022;58:39 (online December 2021). PMID 35056347. doi:10.3390/medicina58010039
- SACN. Vitamin D and health. 2016.
- Schwarz F et al. Peri-implantitis. J Clin Periodontol 2018;45 Suppl 20:S246–66. PMID 29926484. doi:10.1111/jcpe.12954
- Sulaiman N et al. Bisphosphonates and dental implants: a systematic review and meta-analysis. Materials (Basel) 2023;16:6078. PMID 37763356. doi:10.3390/ma16186078
- Werny JG et al. Does vitamin D have an effect on osseointegration of dental implants? A systematic review. Int J Implant Dent 2022;8:16. PMID 35403929. doi:10.1186/s40729-022-00414-6