InvestIgatIon of cytotoxIcIty and antIbacterIal effect of boron-contaInIng nano-hydroxyapatIte

Introduction: Different regenerative materials are used to protect and stimulate pulp tissue. Objectives: This in vitro study aimed to examine the cytotoxicity of different doses of boron-containing nano-hydroxyapatite (B-nHAp) and its antibacterial effect. Material and methods: B-nHAp was synthesized with microwave-assisted chemical precipitation method at different rates, such as 1%, 5%, and 10%. The extracts were prepared in separate tubes: 1%, 5%, 10% B-nHAp, and nHAp 50 mg/ml. Cytotoxicity test was performed on L929 mouse fibroblasts for 24 and 72 hours. Antibacterial analysis was performed with Streptococcus mutans bacteria using micro-dilution method. Cell viability values were evaluated with two-way analysis of variance (ANOVA) test (p < 0.05). Results: B-nHAp was successfully synthesized in XRD and SEM analyses. Nano-hydroxyapatite showed more cell viability than control group at 24 and 72 hours. All B-nHAp extracts demonstrated less cell viability at the end of 24 hrs. than control group. However, 1% B-nHAp cell viability decreased more in the B-nHAp group compared with the control group, while 5% and 10% B-nHAp showed high cell viability after 72 hours of incubation. B-nHAp demonstrated less antibacterial effect on Streptococcus mutans compared with nHAp. Conclusions: According to the results, the addition of boron to nano-hydroxyapatite does not make a significant contribution to increase the regenerative and antibacterial properties of the material.