What is meant by biocompatibility? How biocompatible are ceramic implants?

Biocompatibility is a mandatory requirement for the clinical use of biomaterials in dentistry. Today, the biocompatibility concept includes not only bio-inertia, but also biofunctionality and biostability. Biocompatibility is defined as ‘the ability of a biomaterial to perform its desired function with respect to a medical therapy, without eliciting any undesirable local or systemic effects on the recipient or beneficiary of that therapy but meanwhile generating the most optimized clinically relevant performance of that therapy’ or as ‘the ability of a material to perform with an appropriate host response in a specific situation’. (Huzum et al. 2021).

The studies show a good proliferation capacity of osteoblasts (Bächle et al. 2007) and fibroblasts (Yamano et al. 2011), no osteoblast cytotoxicity (Möller et al. 2012) and high viability of dental pulp stem cells (Wei et al. 2019) when cultured in contact with zirconia.

Assessments in patients also demonstrated that the soft tissue around zirconia implants and abutments is healthy with no inflammatory signs (Blaschke et al. 2006) and a blood flow in the gum tissue similar to natural teeth (Kajiwara et al. 2015). Barwacz et al. (2015) showed that inflammation around zirconia and titanium abutments was similar but there was no excessive expression of pro-inflammatory mediators, and the little signs of inflammation support the clinical biocompatibility of both zirconia and titanium. The excellent biocompatibility of zirconia is also confirmed by Hisbergues et al. (2009) and Cionca et al. (2017).

References

Barwacz CA, Brogden KA, Stanford CM, Dawson DV, Recker EN, Blanchette D. Comparison of pro-inflammatory cytokines and bone metabolism mediators around titanium and zirconia dental implant abutments following a minimum of 6 months of clinical function. Clin Oral Implants Res. 2015;26(4):e35-e41. doi:10.1111/clr.12326.

Bächle M, Butz F, Hübner U, Bakalinis E, Kohal RJ. Behavior of CAL72 osteoblast-like cells cultured on zirconia ceramics with different surface topographies. Clin Oral Implants Res. 2007;18(1):53-59. doi:10.1111/j.1600-0501.2006.01292.x.

Blaschke C, Volz U. Soft and hard tissue response to zirconium dioxide dental implants-a clinical study in man. Neuro Endocrinol Lett. 2006;27 Suppl 1:69-72.

Cionca N, Hashim D, Mombelli A. Zirconia dental implants: where are we now, and where are we heading?. Periodontology 2000. 2017;73(1):241-258. doi:10.1111/prd.12180.

Hisbergues M, Vendeville S, Vendeville P. Zirconia: established facts and perspectives for a biomaterial in dental implantology. J Biomed Mater Res B Appl Biomater. 2009;88(2):519-529. doi:10.1002/jbm.b.31147.

Huzum B, Puha B, Necoara RM, Gheorghevici S, Puha G, Filip A, Sirbu PD, Alexa O. Biocompatibility assessment of biomaterials used in orthopedic devices: An overview (Review). Exp Ther Med. 2021 Nov;22(5):1315. doi: 10.3892/etm.2021.10750. Epub 2021 Sep 17. PMID: 34630669; PMCID: PMC8461597.

Kajiwara N, Masaki C, Mukaibo T, Kondo Y, Nakamoto T, Hosokawa R. Soft tissue biological response to zirconia and metal implant abutments compared with natural tooth: microcirculation monitoring as a novel bioindicator. Implant Dent. 2015;24(1):37-41. doi:10.1097/id.0000000000000167.

Möller B, Terheyden H, Açil Y, et al. A comparison of biocompatibility and osseointegration of ceramic and titanium implants: an in vivo and in vitro study. Int J Oral Maxillofac Surg. 2012;41(5):638-645. doi:10.1016/j.ijom.2012.02.004.

Wei C, Gong T, Pow EHN, Botelho MG. Adhesive and oxidative response of stem cell and pre-osteoblasts on titanium and zirconia surfaces in vitro. J Investig Clin Dent. 2019;10(3):e12407. doi:10.1111/jicd.12407.

Yamano S, Ma AK, Shanti RM, Kim SW, Wada K, Sukotjo C. The influence of different implant materials on human gingival fibroblast morphology, proliferation, and gene expression. Int J Oral Maxillofac Implants. 2011;26(6):1247-1255.