Face it: we’re seeing many more patients with dental implants. Dental implants are a viable solution for tooth loss with predictable results and high success rates.
I remember one of my professors, Dr. Paul Rosen, saying over and over, “Implants are not teeth; you cannot treat implants like natural teeth,” during his implant classes. One of the leading factors contributing to implant loss is poor oral hygiene. Patients with dental implants require regular maintenance visits for assessing the implant and surrounding tissues to prevent peri-implantitis.
Also, strict adherence to an oral hygiene regimen, including regular brushing, water flossing, antimicrobial rinses, and possibly the use of fluoride-containing products, will help with overall health for a mixed dentition comprised of natural teeth and dental implants.
Market research suggests that 50% of dental implant cases are single-tooth replacements due to tooth loss related to trauma or caries. Dental hygienists and dentists often prescribe higher fluoride concentrate dosages for those at a high risk of the disease.1 Stannous fluoride has antibacterial benefits, but fluoride will not benefit titanium implants. The focus of fluoride should be on the anticariogenic benefit of natural teeth. Here I’ll discuss fluoride’s effect on titanium implants for patients with mixed dentition.
Titanium peri-implantitis and corrosion
Peri-implantitis is a multifactorial condition related to implant placement, host response, occlusal trauma, prosthetic design, poor oral hygiene, bone loss, gingival recession, and exposure of the dental implant to the oral environment. Implant disinfection, grafting to rebuild peri-implant supporting structure are common treatments.
Titanium and zirconia dental implants are commonly used for their biocompatibility and durability. Titanium implants are more popular in the US because of their affordability, high strength, and resistance to corrosion.2
Corrosion of titanium dental implants has been associated with implant failure and is considered one of the triggering factors for peri-implantitis.3 Recent studies suggest corrosion may correlate with peri-implantitis progress by triggering microbial dysbiosis.4 Corrosion products and metal ions resulting from metal dissolution can lead to adverse tissue reactions in the oral environment. What is most concerning is the effect on osseointegration; regeneration may not happen once surface passivation is lost.3
There is concern that the use of fluoride may contribute to the corrosion of dental implants. Critics of fluoride treatments, or even fluoride toothpaste, warn of the risk of corrosion over time.
One study demonstrated corrosion on titanium alloy commonly used in orthodontic wires, not dental implants, with acidulated phosphate fluoride (APF) gel.5 Use of APF gel fluoride in trays was a more common practice before the introduction of fluoride varnish. This leads to a recommendation for patients with implants to avoid fluoride with high acidic pH, such as APF fluoride gel.
It has been demonstrated that fluoride can cause corrosion to exposed dental implant surfaces in the presence of an acidic pH.6 Therefore, salivary pH conditions should be considered when prophylactic actions of NaF and SnF2 fluoride varnishes are administered.7,8
What are the safe pH ranges for fluoride use on titanium implants?
In 1998, confined fluoride ions demonstrated the corrosive process on titanium as soon as the pH dropped below 3.5.9 Fluoride-containing solutions (pH 7.0) did not damage the surface of cast commercially pure titanium (CP Ti) and can be used by patients with titanium-based restorations.10 This evidence gives us guidelines to monitor both product and salivary pH in a safe range between 3.5 and 7.0 pH.
Some believe low concentration neutral pH OTC fluoride-containing products may be safely used on titanium dental implants if salivary pH is controlled. The concern is that patients with a high caries rate who receive prescriptions for high-concentration fluoride products typically have an acidic pH. The high fluoride concentration and the acidic pH in toothpaste used to prevent caries may modify the surface structure of implants made of titanium.11
Individual patient assessment is crucial. We should tailor recommendations for patients with mixed dentition of titanium implants and natural teeth with multiple fillings based on the patient’s needs and risk factors. Hygienists must focus on alternatives to reduce caries by balancing salivary pH or recommend xylitol products over high-concentration fluoride prescriptions to prevent corrosion of dental implants. Educating patients about factors contributing to high salivary pH, such as dietary habits and rinsing after consuming acidic or sugary foods, can minimize the risk of caries.
Regular application of fluoride can be part of a comprehensive oral hygiene regimen. Fluoride helps strengthen natural teeth and reduce the risk of decay. By preserving the health of adjacent teeth, fluoride varnish contributes to the overall health of the mixed dentition.
Dental hygienists should consider incorporating salivary pH testing to monitor safe fluoride use for patients with dental implants. Use daily use of high concentration prescription fluoride in combination with prolonged exposure to an acidic salivary pH may lead to corrosion or damage to the implant surface. Neutral sodium or stannous fluoride varnish treatments administered by a dental professional in controlled amounts are at lower risk of adverse effects on dental implants if administered in neutral salivary pH. More research is needed on this topic.
References
1. Anwar EM, Kheiralla LS, Tammam RH. Effect of fluoride on the corrosion behavior of Ti and Ti6Al4V dental implants coupled with different superstructures. J Oral Implantol. 2011;37:309–317. doi:10.1563/AAID-JOI-D-09-00084
2. Kasemo B. Biocompatibility of titanium implants: surface science aspects. J Prosthet Dent. 1983;49(6):832-837. doi:10.1016/0022-3913(83)90359-1
3. Rodrigues, D, Valderrama, P, Wilson, et al. Titanium corrosion mechanisms in the oral environment: a retrieval study: Materials (Basel). 2013;6(11): 5258–5274. doi:10.3390/ma6115258
4. Nagay, B, Cordeiro, J, Valentim, BaraoA. Insight into corrosion of dental implants: from biochemical mechanisms to designing corrosion-resistant materials. Curr Oral Health Rep 2022;9(2):7-21. doi:10.1007/s40496-022-00306-z
5. Pintu-on C, Tipanan Y. Exposure to the oral environment enhances the corrosion of metal orthodontic appliances caused by fluoride-containing products: Cytotoxicity, metal ion release, and surface roughness. Amer J Orthod Dentofacial Orthopedics. 2021;160(1)101-112.
6. Goutam M, Kumar S, Sushma KN, et al. Assessment of effect of fluoride on titanium dental implants. J Pharm Bioallied Sci. 2022;14(Suppl 1):S220-S221. doi:10.4103/jpbs.jpbs_2_22
7. Noguti J, de Oliveira F, Peres RC, Renno AC, Ribeiro DA. The role of fluoride on the process of titanium corrosion in oral cavity. Biometals: 2012;25(5):859-862. doi: 10.1007/s10534-012-9570-6.
8. Suszcynsky-meister E, Shauchuk A, Hare T, et al. Chemical effects of stannouse and sodium fluoride dental treatments on titanium alloy surfaces. Abstract Archives. 2018. https://iadr.abstractarchives.com/abstract/47am-2855013/chemical-effects-of-stannous-and-sodium-fluoride-dental-treatments-on-titanium-alloy-surfaces
9. Reclaru L, Meyer JM. Effects of fluorides on titanium and other dental alloys in dentistry. Biomaterials. 1998;19(1-3):85-92. doi:10.1016/s0142-9612(97)00179-8
10. Toniollo MB, Rodrigo T, Madedo AP, et al. Effect of fluoride-containing solutions on the surface of cast commercially pure titanium. Braz Dent J. 2009;20(3). https://doi.org/10.1590/S0103-64402009000300005
11. Stájer A, Radnai M, Pelsoczi K I, Turzó K, Oszkó A, Fazekas A. The effect of fluorides on the surface structure of titanium implants. Fogorv Sz. 2006;99(2):53-59.
