Title Zinc Oxide Can Potentially Reduce the Risk of Peri-Implantitis and Implant Failure
Clinical Question In patients with dental implants, does a zinc oxide coating on titanium implants reduce the risk of peri-implantitis?
Clinical Bottom Line In-vitro studies show that zinc oxide can significantly inhibit and kill microbes as well as stimulate osteoblast activity. Further clinical trials are needed to test the efficacy of a zinc oxide coating in reducing peri-implantitis.
Best Evidence  
PubMed ID Author / Year Patient Group Study type
(level of evidence)
26497232Abdulkareem/2015Human saliva-derived microbial organisms Laboratory study
Key resultsAntimicrobial activity of titanium discs with no coating (control), hydroxyapatite (HA), zinc oxide (ZnO), or 50% ZnO + 50% HA on human saliva-derived microbial organisms was tested in vitro. No significant differences were found in the first 24 hours (p > 0.05). However, at the 96 hour interval, biofilm thickness was significantly reduced in the ZnO group and the ZnO+HA group (p < 0.0001 and p < 0.01, respectively) as compared to the control group, while the HA group showed no significant difference with the control. Additionally, significant bactericidal activity of both the ZnO group and the ZnO+HA groups against aerobes (p < 0.05), Streptococcus spp. (p < 0.01), and anaerobes (p < 0.01) compared to the controls were found.
24862288Memarzadeh/2015Staphylococcus aureusLaboratory study
Key resultsZinc oxide and hydroxyapatite nanoparticle-coated glass substrates demonstrated significant, dose dependent killing of Staphylococcus aureus compared with the control (p < 0.05) using the CFU counting method. Additionally, a reduction in bacterial colonization of the coated material compared to the uncoated material was observed under scanning electron microscopy. Cytotoxicity testing of these treatments on osteoblasts found that the cell morphology was characteristic of a normal osteoblast and did not affect the cytoskeletal elements involved in adhesion. Lactose dehydrogenase, TNF- and IL-6 release was also undetectable implying that there is inflammatory effect or cell stress. Finally, an increase in proliferation after 5 and 10 days, as well as a significant increase in alkaline phosphatase activity on treated samples (p < 0.05) was found indicating perhaps another beneficial effect of zinc oxide.
Evidence Search "zinc oxide"[MeSH Terms] OR ("zinc"[All Fields] AND "oxide"[All Fields]) OR "zinc oxide"[All Fields]) AND ("dental implants"[MeSH Terms] OR ("dental"[All Fields] AND "implants"[All Fields]) OR "dental implants"[All Fields] OR ("dental"[All Fields] AND "implant"[All Fields]) OR "dental implant"[All Fields]) AND coating[All Fields]
Comments on
The Evidence
The Abdulkareem et al. study not only measures the colony forming units (CFUs) of the bacteria but the biofilm structure as well using widely used tests. This is important because bacteria that exist in biofilms, its natural mode, can be in a viable, non-culturable (VNC) state. These bacteria are alive and capable of being pathogenic. Furthermore, bacteria in a biofilm are better protected and antimicrobial agents may not be effective against them. Thus, antimicrobial studies that do not test biofilms may overestimate the efficacy of the treatment. Finally, the study uses a polymicrobial sample derived from human saliva, which replicates the oral cavity more accurately than just one organism alone. Many of the results in the Memarzadeh et al study were qualitative observations. Quantitative studies are needed to confirm their findings. For example, observing normal cytoskeletal morphology could be confirmed with normal expression of signaling in various cytoskeletal pathways or an adherence study could be performed indicating normal adherence to a substrate compared to the control. Regarding the microbial studies, the authors do not indicate how they measured their bacterial numbers. Numbers were reported in CFUs but they do not indicate if they were plated after treatment and counted, used spectrophotometry, etc. The time points of when the bacteria were counted is also not specified which can make a significant impact on the viability of the bacteria if the bacteria were beginning to enter the log phase. Biofilm was characterized via SEM but no quantitative studies were used.
Applicability Peri-implantitis can lead to a failure in osseointegration of the implant. While only 2.7% of implants develop peri-implantitis, 67% of those fail (Camps-Font et al. 2015, Journal of Implant Dentistry, Vol. 24, pg. 713). The inhibition of the microbes responsible would make a significant impact on implant success. In vitro studies showed that zinc oxide coated on titanium kill human derived microbes. Another in vitro study showed that zinc oxide is not only non-toxic to osteoblasts, but may also stimulate and improve osseointegration. Further clinical trials are needed to test if zinc oxide will reduce the number of microorganisms in patients at the implant site.
Specialty (General Dentistry) (Oral Surgery) (Periodontics) (Prosthodontics) (Restorative Dentistry)
Keywords Dental implant, implant, implantology, antimicrobial, antibacterial, perimplantitis, zinc oxide, implant coating, implant prognosis, implant osseointegration, osseointegration, implant outcomes, zinc oxide, zinc
ID# 2995
Date of submission 03/01/2016
E-mail yatesd@livemail.uthscsa.edu
Author Daniel Yates
Co-author(s) e-mail
Faculty mentor Kyumin Whang, PhD
Faculty mentor e-mail Whang@uthscsa.edu
Basic Science Rationale
(Mechanisms that may account for and/or explain the clinical question, i.e. is the answer to the clinical question consistent with basic biological, physical and/or behavioral science principles, laws and research?)
None available
Comments and Evidence-Based Updates on the CAT
None available