Antibacterial and bioactive coatings on titanium implant surfaces

Abstract

Various surface modifications have been tried for enhancing osseointegration of the dental implants like mechanical and/or chemical treatments and deposition of calcium phosphate coatings. The objective of this research was to develop calcium-phosphate based thin coatings with antibacterial and bioactive properties for potential application in dental implants. Titanium (Ti) discs were immersed in different calcifying solutions: CaP (positive control), F-CaP, Zn-CaP, and FZn-CaP and incubated for 24 h. Negative control was uncoated Ti discs. Coated surfaces were characterized using X-ray diffraction, scanning electron microscopy and energy dispersive spectroscopy. Antibacterial properties were tested using Porphyromonas gingivalis because of its strong association with periodontal and peri-implant infections. Bacterial adhesion and colonization were studied at different timepoints. The coated surfaces had compositional characteristics similar to that of bone mineral and they inhibited the growth, colonization and adherence of P. gingivalis, resulted in reduced thickness of biofilms and bacterial inhibition in the culture medium as compared to the positive and negative controls (p < 0.05). There was no significant difference between the experimental groups (p > 0.05). It has been previously demonstrated that these coatings have excellent in vitro bioactivity (formed carbonate hydroxyapatite when immersed in a simulated body fluid). Such coatings can enhance osseointegration and prevent infection in implants, thereby improving the success rates of implants. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 2218-2227, 2017.

Keywords: Porphyromonas gingivalis; antibacterial; bioactivity; dental implant; implant coatings.

Fig. 1

SEM images and corresponding XRD spectra of different Ti disc surfaces. A: uncoated, B: CaP coated, C: F-CaP coated, D: Zn-CaP coated, E: FZn-CaP coated.

Fig. 2

SEM images showing adhesion of P. gingivalis at 48 h and 72 h on various Ti disc surfaces. A: uncoated, B: CaP coated, C: F-CaP coated, D: Zn-CaP coated, E: FZn-CaP coated.

Fig. 3

Graph showing bacterial adhesion of different surfaces for 48 h and 72 h.

Fig. 4

SEM images of Ti discs inoculated with bacterial culture for 3 day and 7 day (bacterial colonization). A: uncoated, B: CaP coated, C: F-CaP coated, D: Zn-CaP coated, E: FZn-CaP coated.

Fig. 5

Colonization of P. gingivalis on different surfaces at 3 day and 7 day.

Fig. 6

Images from confocal microscope showing biofilm on Ti discs incubated with bacterial culture for 3 day and 7 day (colonization). A: uncoated, B: CaP treated, C: F-CaP treated, D: Zn-CaP treated, E: FZn-CaP treated.