IADR Abstract Archives
Dentine Interactions of Hybrid Self-adhesive Composite/GIC Using Advanced Optical Imaging
Objectives: This study compared the micro-shear bond strength (µSBS) and morphological interactions of sound and demineralised dentine to an experimental hybrid composite/GIC material (X) with conventional glass ionomer cement (G) EQUIA® Forte (GC) and Filtek™ Bulk Fill composite (BF) with Scotchbond™ Universal Adhesive (3M).
Methods:
Sixty molars were randomly distributed into six groups of sound and demineralised dentine (phosphoric acid 37% etched for 1 min.). All samples were bonded with a micro cylinder of three tested materials as per manufactures’ instructions for G, BF and X material. Bond strength was measured at 24hrs and following 4 weeks’ storage in phosphate buffered saline. A further nineteen teeth were used to evaluate microscopically the interaction of the materials with dentine using fluorescence double labelled micro-permeability, fluorescence lifetime and second harmonic generation by two-photon excitation imaging; assessing optical changes before and after storage with the materials. Raman spectroscopy was used to detect the percentage changes in the intensity of the mineral phosphate peak, which were correlated with micro-hardness readings of the same samples.
Results:
The experimental material (X) showed a significant increase in µSBS compared to (G) EQUIA® Forte (p<0.006). They both showed an improved bond with the etched dentine compared to unetched/sound dentine (p<0.0001). Filtek™ composite (BF) recorded the highest bond strength values amongst all groups (p<0.00001). Storage time didn’t affect the bond strength significantly (p=0.89, 0.78). Good adaptation, no voids and a similar increase in the mineral peaks and hardness were noted with the etched dentine for the G & X groups.
Conclusions:
Pre-conditioning of the dentine surface may improve the adhesion properties of the experimental material and could enhance dentine wettability and ionic interactions at the interface. Multiphoton fluorescence microscopy is a promising minimally invasive microscopic technique to study the dental tissue/materials interface overtime.
Methods:
Sixty molars were randomly distributed into six groups of sound and demineralised dentine (phosphoric acid 37% etched for 1 min.). All samples were bonded with a micro cylinder of three tested materials as per manufactures’ instructions for G, BF and X material. Bond strength was measured at 24hrs and following 4 weeks’ storage in phosphate buffered saline. A further nineteen teeth were used to evaluate microscopically the interaction of the materials with dentine using fluorescence double labelled micro-permeability, fluorescence lifetime and second harmonic generation by two-photon excitation imaging; assessing optical changes before and after storage with the materials. Raman spectroscopy was used to detect the percentage changes in the intensity of the mineral phosphate peak, which were correlated with micro-hardness readings of the same samples.
Results:
The experimental material (X) showed a significant increase in µSBS compared to (G) EQUIA® Forte (p<0.006). They both showed an improved bond with the etched dentine compared to unetched/sound dentine (p<0.0001). Filtek™ composite (BF) recorded the highest bond strength values amongst all groups (p<0.00001). Storage time didn’t affect the bond strength significantly (p=0.89, 0.78). Good adaptation, no voids and a similar increase in the mineral peaks and hardness were noted with the etched dentine for the G & X groups.
Conclusions:
Pre-conditioning of the dentine surface may improve the adhesion properties of the experimental material and could enhance dentine wettability and ionic interactions at the interface. Multiphoton fluorescence microscopy is a promising minimally invasive microscopic technique to study the dental tissue/materials interface overtime.