Potent Antibacterial and Antibiofilm Activities of a Synthetic Remineralizing Preparation of Nano-Hydroxyapatite Against Cariogenic Streptococcus mutans Using an Ex-vivo Animal Model

Abstract

AimThe aim to this study is to evaluate the biocompatibility and antibiofilm actions of two nano-hydroxy apatite (NHA).MethodologyNano-hydroxy apatites are biomaterials use in direct contact with living tissues. Therefore, they should be tested for their safety beside assessment of their minimum inhibitory (MIC) and minimum bactericidal concentration (MBC) using broth microdilution method. One hundred and twenty extracted bovine incisors were collected and cleaned to ensure the absence of any defects. Enamel blocks with different size (2 × 2 × 3 mm) and (5 × 5 × 2 mm) were prepared from their labial surfaces using an isomet saw. Enamel blocks are used for detecting the suitable concentration will be used in the following experiments using energy dispersive X-ray analysis (EDX). The remaining enamel blocks divided into 5 equal groups to detect inhibitory effect against bacterial adhesion to the initial enamel caries like lesions using viable count technique beside the antibiofilm activity against mature biofilm of Streptococcus mutans (S. mutans) using confocal laser microscopy. The remaining enamel blocks were used as a representing data for detecting surface topography for each group by using the scanning electron microscopy (SEM).ResultThe data showed safety of NHA suspensions. Additionally, only NHA suspension of large nanoparticle size (NHA-LPS) had MIC of 1.25 mg/ml against S. mutans. Also, have the higher percentages of Ca and P in the enamel blocks. Furthermore, the lowest level of bacterial adhesion was recorded in (group III) treated by NHA-LPS which was non-significantly different with the positive control group V. Biofilm thickness in group IV treated with NHA-small particle size (SPS) recorded high biofilm thickness followed by group III. Interestingly, group III showed greater killing effect against mature biofilm which is slightly higher than the positive control group V. In group III, surface topography revealed very smooth enamel surface with closed pores. Accordingly, NHA-LPS suspension had antiadhesive, antibacterial, and antibiofilm effect against cariogenic S. mutans representing a promising possibility to be recommended for safe effective remineralization.

Effect of N-Acetylcysteine on initial Carious Enamel Lesions in primary teeth: an In-vitro study

“…It was created by keeping the specimens for 96 h at 37 °C in the demineralization solution to produce a subsurface demineralization with an undamaged surface mimicking an initial enamel lesion. ; this agreed with El-Gar et al, [ 20 ].…”

“…Ten specimens were randomly selected to evaluate normal enamel surfaces while the remaining thirty specimens were dipped in a bath containing demineralizing solution to initiate enamel caries-like lesions. Each specimen had been exposed to 20 ml of demineralizing solution (2.2 mMol CaCl 2 , 2.2 mMol Na 3 Hpo 4 , 0.05 mMol acetic acid, 1 mMol KOH (pH 4.2)) [ 18 , 19 ] in a separate capped-test tube for 96 h, in an incubator at 37 °C [ 20 ]. The demineralizing solution was formulated in the Chemistry Department, Faculty of Science, Suez University; its pH was measured continuously by a digital pH meter & adjusted to 4.2 using 1 mMol potassium hydroxide [ 16 ].…”

Antibacterial activity of nano-hydroxyapatite paste of snakehead fish bone against S. mutans: an in vitro study

“…10 Furthermore, El-Gar et al showed that nano-hydroxyapatite aqueous suspensions has potent antibacterial and antiadhesive actions that can prevent formation of S. mutans. 11 This result was in line with Hariani et al which explained that Snakehead (Channa striata) fish bone nano-hydroxyapatite solution has antibacterial properties against S. aureus and E. coli. 12 There has been no research examining the antibacterial ability of nano-hydroxyapatite paste of Snakehead (Channa striata) fish bone against S.mutans.…”

Nanohydroxyapatite in dentistry: A comprehensive review

“…Apart from remineralization various other applications of nanohydroxyapatite in dentistry is also extensively researched upon. Its use in regeneration has opened new vistas in the field of implantology [ El-Gar et al, 2022 ]. However, long term studies are required to establish safety of continuous use nHA in daily life.…”

“… High-quality resin tags in demineralized enamel with enhanced mineral density, resin penetration and smooth surfaces Wahba et al, 2022 [96] In-vitro Comparison of fluoride varnish, fluoride mouthwash, Self- Assembling Peptide (P 11 -4), CPP-ACP, and nHA in prevention and arrest of Primary Tooth Enamel Lesions Fluoride varnish, fluoride mouthwash showed caries-preventive effects whereas other agents did not show any effect Sebastian et al, 2022 [97] In-vitro Comparison of CPP-ACP, nHA and Calcium Sucrose Phosphate (CSP) on artificial enamel lesion CSP showed highest surface microhardness followed by nHA and CPP-ACP Erdilek et al, 2022 [98] In-vitro Comparison of remineralization potential of fluoride gel, sodium fluoride toothpaste, and homemade nHA paste on artificial early enamel caries. Homemade nHA paste had a enhanced remineralization potential of early enamel caries lesions El-Gar et al, 2022 [99] In-vitro Assessment of biocompatibility and antibiofilm activity of suspension of nHA of large nanoparticle size (NHA-LPS) and nHA -small particle size (NHA-SPS) NHA-LPS suspension showed enhanced bacterial adhesion and biofilm thickness in compared to NHA-SPS. Atef et al, 2022 [1 0 0] In-vitro Effectiveness of diode laser, fluoride varnish and nHA on the enamel microhardness and microstructural alterations of the primary teeth enamel was assessed All the remineralizing agents were equally effective in increasing microhardness and maintaining enamel microstructure integrity.…”