Potential Use of L-Arginine Amino Acids towards Proliferation and Migratory Speed Rate of Human Dental Pulp Stem Cells (hDPSCs).

OBJECTIVE: Inflamed pulp has a decreased amount of protein and amino acids. L-Arginine is a semi-essential amino acid, the production of which is insufficient under oxidative stress and inflammation. L-Arginine is the sole substrate for nitric oxide synthase (NOS) to produce nitric oxide (NO), which plays an important role in cell proliferation and migration. This study aims to evaluate the proliferation and migration rate of hDPSCs after L-Arginine supplementation. METHODS: Serum-starved hDPSCs were divided into four groups: control: hDPSCs in Dulbecco's modified Eagle medium; hDPSCs in 300 µmol/L of the L-Arginine based culture media group; hDPSCs in 400 µmol/L of the L-Arginine based culture media group; and hDPSCs in 500 µmol/L of the L-Arginine based culture media group, which were planted in two separate 24-well-plates (5x104 cell/well) for proliferation and migration evaluation. The proliferation of all groups was measured by using a cell count test (haemacytometer and manual checker) after 24 h. The migratory speed rate of all groups was measured by using cell migration assay (scratch wound assay) after 24 h. Cell characteristics were evaluated under microscope (Inverted microscope, Zeiss®, Observer Z1, UK) that can be read through image-J® interpretation. This image J represented the measurement of migratory speed rate (nm/h) data. Statistical analysis was conducted using one-way ANOVA and post hoc Bonferroni (p<0.05) for proliferation and post hoc LSD (p<0.05) for migration (IBM SPSS Statistics Software, version 22.0). RESULTS: There was a statistically significant difference in hDPSC proliferation among various concentration groups of the L-Arginine based solution (300, 400 and 500 µmol/L) compared to the control group. There was a statistically significant difference in the migratory speed rate of hDPSCs in 500 µmol/L of the L-Arginine based solution group compared to lower concentrations and control group. CONCLUSION: The highest potency of hDPSC proliferation and migration was observed in the 500 µmol/L group. (EEJ-2023-01-08).

The effect of rice husk nanosilica hydroxyl compound on dentin biomineralization.

Rice husk nanosilica contains hydroxyl for dentin remineralization. The aim of this study was to analyze and correlate the ability of rice husk nanosilica to induce hydroxyapatite dentin. The detachment of hydroxyl from rice husk nanosilica was analyzed using the sol-gel and pyrolysis methods with Fourier transform infrared spectroscopy. Subsequently, exposing of the demineralized dentin to rice husk nanosilica was performed for a comparison. The formation of hydroxyapatite on dentin was analyzed using X-ray diffraction. The amount of hydroxyl released from the two methods was then correlated with the hydroxyapatite that formed at the dentin. The extraction of hydroxyl on rice husk nanosilica with two methods was the same. Analysis of the amount of hydroxyapatite dentin with both the methods corresponds to each other. The correlation test obtains the value of R = 0.656. Rice husk nanosilica has a similar capability to release hydroxyl compound and form hydroxyapatite dentin using two methods. The creation of hydroxyapatite dentin is not only caused by the exposure of rice husk nanosilica but also owing to other factors that might reinforce the process of hydroxyapatite formation.

Comparison of Advanced Platelet Rich Fibrin (A-PRF) and Culture Media Conditioned Warton's Jelly (CMCWJ) on Fibroblast Cells Proliferation

Objective: To compare the potency of fibroblast cells proliferation in 12.5% and 25% Culture Media Conditioned Warton's Jelly (CMCWJ) and Advanced Platelet Rich Fibrin (A-PRF) cultured medium. Material and Methods: Fibroblast cells were divided into five groups: Group I (Control Group): serum-starved fibroblast without any treatment as a negative control; Group II: fibrolast that supplemented in 12.5% CMCWJ medium; Group III: fibrolast that supplemented 12.5% A-PRF medium; Group IV: fibrolast that supplemented 25% CMCWJ medium, and Group V: fibrolast that supplemented 25% A-PRF medium. The fibroblasts proliferation was counted by an automated cell counter. Statistical analysis was performed using One-way ANOVA and Post hoc Tamhane test was conducted to analyze the potential fibroblast proliferation differences in different concentration of CMCWJ and A-PRF group. Results: There were no significant differences in the fibroblast cell proliferation between GI and GIV, GII and GIV, GII and GIII, GII and GV, also GIV and GV. There were significant differences between GI and GII, GI and GIII, GI and GV, also GIII and GIV. Conclusion: The 12.5% CMCWJ group, 12.5% A-PRF group and 25% A-PRF group has excellent potential ability of fibroblast cells proliferation, meanwhile 25% CMCWJ group has the lowest mean potency of fibroblast cells proliferation compared to other groups. The 12.5% A-PRF Group has the highest mean of fibroblast cell proliferation amongst other groups.

Comparison of Apical Adaptation Between Several Obturation Methods: An in Vitro Study

Objective: To compare lateral compaction obturation with carrier-based gutta-percha and downpack-backfill. Material and Methods: Ninety tooth with single root canal were prepared with rotary Protaper and divided into 3 groups: Group 1 obturated with lateral heated compaction (LHC), Group 2 with carrier-based gutta-percha (CP) and Group 3 with downpack-backfill (DB). The apical one-third adaptation was determined by examining the dye penetration between obturation material and root canal wall on the horizontal cut samples. The data received was analyzed using SPSS 17 software. Chi-square statistical test was done with level of significance (α) of 0.05. Results: The DB group had the highest amount of score of 0, followed by CP group and LHC group. The DB group had 28 samples (93.3%) with score of 0, which was the largest compared to the CP and LHC group. All groups had some score 2, and score 3 and 4 were only examined in the LHC group Adaptation of the apical one-third on DB group had the best result, followed by CP and LHC group (p>0.05). Conclusion: The adaptation of apical one-third by downpack-backfill was the best among the three groups, but there was no statistically significant difference among those groups.