IADR Abstract Archives
Impact of Dentin Conditioning with Chitosan-Hydroxyapatite Nanocomplexes on Sealer-Dentin Interface
Objectives:
This study aimed to (1) develop and characterize Chitosan-Hydroxyapatite precursor (C-HA) nanocomplexes and (2) evaluate the effect of dentin conditioning with C-HA nanocomplexes on depth of tricalcium silicate sealer (TCS) penetration, interfacial remineralization and dentin mechanical property.
Methods: The experiments were divided into three phases. Phase-I: Physico-chemical characterization of C-HA nanocomplexes was conducted using zeta-potential, polydispersity and water contact-angle measurements. Bioactivity was evaluated using films of C-HA nanocomplexes (n=10), incubated in remineralizing medium (3d) and analyzed with Scanning Electron Microscopy for ultrastructural evaluation, x-ray Diffraction and Fourier Transformation Infrared Spectroscopy to assess nature of mineral formed. Ultimate tensile strength (UTS) of dentin beams (n=10/group) was assessed with/without conditioning with C-HA nanocomplexes in conditioned and control groups. Phase-II: Depth of sealer penetration after C-HA nanocomplexes conditioning was evaluated using fluorescent imaging (n=12/group) in conditioned and control group. The % area penetration, mean and maximum penetration depth was calculated at 4 and 6mm levels from root apex.
Data from contact-angle measurements, mechanical testing and penetration assessment parameters were subjected to independent samples T-test with significance level set at p<0.05.
Phase-III: Chemical characterization of tricalcium silicate sealer-dentin interface post C-HA nanocomplexes conditioning of demineralized dentin discs (n=2/group) was conducted using Time-of-Flight Secondary Ion Mass Spectrometry and ultrastructural evaluation with transmission electron microscopy.
Results: 2mg/ml of C-HA nanocomplexes was chosen as polyanionic, non-aggregating, hydrophilic and bioactive formulation. Deeper (p<0.05) sealer penetration was seen at 4mm level for all assessment parameters and % area penetration at 6mm for C-HA nanocomplexes group. Sealer-dentin interfacial characterization showed presence of “ion-rich layer” (5um) with abundant phosphates, calcium, calcium-phosphates and chitosan fragments at surface/sub-surface dentin in conditioned group.
Conclusions: The study highlighted the role of C-HA nanocomplexes in enhancing TCS penetration, interfacial remineralization and mechanical property of dentin.
This study aimed to (1) develop and characterize Chitosan-Hydroxyapatite precursor (C-HA) nanocomplexes and (2) evaluate the effect of dentin conditioning with C-HA nanocomplexes on depth of tricalcium silicate sealer (TCS) penetration, interfacial remineralization and dentin mechanical property.
Methods: The experiments were divided into three phases. Phase-I: Physico-chemical characterization of C-HA nanocomplexes was conducted using zeta-potential, polydispersity and water contact-angle measurements. Bioactivity was evaluated using films of C-HA nanocomplexes (n=10), incubated in remineralizing medium (3d) and analyzed with Scanning Electron Microscopy for ultrastructural evaluation, x-ray Diffraction and Fourier Transformation Infrared Spectroscopy to assess nature of mineral formed. Ultimate tensile strength (UTS) of dentin beams (n=10/group) was assessed with/without conditioning with C-HA nanocomplexes in conditioned and control groups. Phase-II: Depth of sealer penetration after C-HA nanocomplexes conditioning was evaluated using fluorescent imaging (n=12/group) in conditioned and control group. The % area penetration, mean and maximum penetration depth was calculated at 4 and 6mm levels from root apex.
Data from contact-angle measurements, mechanical testing and penetration assessment parameters were subjected to independent samples T-test with significance level set at p<0.05.
Phase-III: Chemical characterization of tricalcium silicate sealer-dentin interface post C-HA nanocomplexes conditioning of demineralized dentin discs (n=2/group) was conducted using Time-of-Flight Secondary Ion Mass Spectrometry and ultrastructural evaluation with transmission electron microscopy.
Results: 2mg/ml of C-HA nanocomplexes was chosen as polyanionic, non-aggregating, hydrophilic and bioactive formulation. Deeper (p<0.05) sealer penetration was seen at 4mm level for all assessment parameters and % area penetration at 6mm for C-HA nanocomplexes group. Sealer-dentin interfacial characterization showed presence of “ion-rich layer” (5um) with abundant phosphates, calcium, calcium-phosphates and chitosan fragments at surface/sub-surface dentin in conditioned group.
Conclusions: The study highlighted the role of C-HA nanocomplexes in enhancing TCS penetration, interfacial remineralization and mechanical property of dentin.