Browsing by Subject "Wettability"

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    Evaluation of contact angle between root canal sealers and dentin treated with calcium hydroxide and irrigation solutions
    (2018) Nakaparksin, Pranai; Platt, Jeffrey; Levon
, John A.; Bringas, Josef S.; Brown, David T.
    Background: Numerous studies have reported the effect of long-term use of calcium hydroxide Ca(OH)2 to dentin. Nevertheless, there is little information available about the effect of Ca(OH)2 on wettability to the dentin. Objective: To investigate the effect of Ca(OH)2 application on dentin for two and four weeks on the wettability of two root canal sealers. Methods: Polished caries-free human dentin discs (n = 156) were allocated into 12 groups; G1 and G3 had two weeks’ treatment, G4 and G6, four weeks treatment. G1 and 101 G4 were treated with sterile water. G2, G3, G5 and G6 were treated with Ca(OH)2. G1, G3, G4, and G6 were irrigated with 6.0-percent NaOCl and 17-percent EDTA while G2, and G5 were irrigated with sterile water. Then, contact angles between Tubli-Seal and the treated dentin surfaces were measured. G7 and G12 were treated in the same fashion but were treated with BC sealer. Surface morphology evaluation of G1 and G6 was carried out by scanning electron microscopy (SEM) and energy-dispersive x-ray spectroscopy (EDX). Statistics were performed using three-way ANOVA and pair-wise comparisons between groups (α = 0.05). Results: Tubli-Seal (G1 through G6) had significantly smaller values for contact angles than BC sealer (G7 through G12) (p < 0.05). For the Tubli-Seal groups (G1 through G6), G4 had the highest mean of contact angles at 104.9 ± 1.9°, whereas G5 presented the lowest mean of contact angles at 85.4 ± 15.1. For the BC sealer groups (G7 through G12), G10 had the highest mean of contact angles at 145.4 ± 1.3°, while G11 demonstrated the lowest mean of contact angles at 130.2 ± 2.6°. Groups with Ca(OH)2 treatment with water irrigation (G2, 5, 11) had significantly lower contact angle than groups with Ca(OH)2 with chemical irrigation (G3, 6, 12) (p < 0.05), except G8, 9. According to SEM and EDX, water irrigation solution showed higher remaining Ca(OH)2 than irrigation with the chemical solution while Ca(OH)2 with chemical irrigation 102 demonstrated no Ca(OH)2 remaining after irrigation, similar to the surface of the control group. Conclusion: Within the limitations of this study, Tubli-seal has better wettability on dentin than BC sealer. Remaining calcium hydroxide demonstrated a trend toward decreased contact angle between dentin and root canal sealers. Moreover, two-minute irrigation with 6-percent NaOCl and 17-percent EDTA can remove calcium hydroxide from polished dentin surfaces.
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    The Oxidative Response of Human Monocytes to Surface Modified Commercially Pure Titanium
    (Frontiers Media, 2021-06-02) De Poi, Robert P.; Kowolik, Michael; Oshida, Yoshiki; El Kholy, Karim; Periodontology, School of Dentistry
    Cellular responses to implanted biomaterials are key to understanding osseointegration. The aim of this investigation was to determine the in vitro priming and activation of the respiratory burst activity of monocytes in response to surface-modified titanium. Human peripheral blood monocytes of healthy blood donors were separated, then incubated with surface-modified grade 2 commercially pure titanium (CPT) disks with a range of known surface energies and surface roughness for 30- or 60-min. Secondary stimulation by phorbol 12-myrisate 13-acetate (PMA) following the priming phase, and luminol-enhanced-chemiluminescence (LCL) was used to monitor oxygen-dependent activity. Comparison among groups was made by incubation time using one-way ANOVA. One sample from each group for each phase of the experiment was viewed under scanning electron microscopy (SEM) and qualitative comparisons made. The results indicate that titanium is capable of priming peripheral blood monocytes following 60-min incubation. In contrast, 30 min incubation time lead to reduced LCL on secondary stimulation as compared to cells alone. At both time intervals, the disk with the lowest surface energy produced significantly less LCL compared to other samples. SEM examination revealed differences in surface morphology at different time points but not between differently surface-modified disks. These results are consistent with the hypothesis that the titanium surface characteristics influenced the monocyte activity, which may be important in regulating the healing response to these materials.