Abstract. To compare the surface roughness of nanofilled and nanohybrid composite resins after polishing using a multi-step technique. 40 composite resin specimens were divided into two groups (20 nanofilled specimens using Filtek Z350 XT [group A] and 20 nanohybrid specimens using Filtek Z250 XT [group B]), prepared, and then polished. After immersion in artificial saliva for 24 hours, the surface roughness was measured with a surface roughness tester. The mean surface roughness results along with the standard deviation of group A were 0.0967 μm ± 0.0174, while the results of group B were 0.1217 μm ± 0.0244. Statistically (with p = 0.05), there were significant differences between each group. The surface roughness of a nanofilled composite resin after polishing with a multi-step technique is better than that of a nanohybrid composite resin. IntroductionNanohybrid and nanofilled resins were discovered along with the development of nanotechnology in the field of conservation dentistry, specifically in restoration [1]. Nanohybird composite resin contains a combination of micro and nano sized filler with a diameter of 0.3-1 µm and 0.02-0.05 µm, respectively [2]. Additionally, nanofilled composite resin has nano particles as filler that are both single (nanomer) and cluster (a group of nano particles called a nanocluster). The size of nano particles varies from 5-75 nm [3].A composite resin surface produced a high surface roughness level after polymerization. Roughness is mainly influenced by the composite resin filler. The larger the size and load of filler particle in a resin product, the rougher the surface [4]. Surface roughness can cause problems such as an increased retention of plaque and microorganisms, which can further develop into secondary caries and restoration failure. Surface roughness can also cause food particles to easily adhere to the restoration, causing increased discoloration. Additionally, surface roughness can wear out the opposite tooth enamel, and reduce patient comfort and satisfaction (a 0.3 µm change in surface roughness can be felt by a patient's tongue). A study showed that bacteria could adhere easily to a composite resin surface with a roughness level of 0.2 µm or more. Furthermore, a rough composite resin surface could produce a dull, unnatural clinical appearance [5].In order to resolve this problem, referring to standard operating procedure, finishing and polishing should be done after every treatment using a composite resin. Polishing is done to produce good physical properties with a smooth and shiny surface so that an esthetic restoration of good quality can be achieved

Objective: To discover the ideal concentration of Advanced Platelet Rich Fibrin (A-PRF) as modification of PRF, for human Dental Pulp Stem Cells (hDPSCs) differentiation. Material and Methods: hDPSCs were devided into five experimental groups: Group I (control group) consist of hDPSCs cultured in 10% FBS, Group II consist of hDPSCs cultured in 1% A-PRF, Group III consist of hDPSCs cultured in 5% A-PRF, Group IV consist of hDPSCs cultured in 10% A-PRF and Group V consist of hDPSCs cultured in 25% A-APRF. All group have been observed for 7 and 14 days and each group had three biological replicates (triplo). Formation of the mineralized nodules was detected after 7 days by Alizarin red-based assay and Dentin Sialophosphoprotein (DSPP) expression after 7 and 14 days quantified by ELISA reader. Statistical analysis was proven with Kruskal-Wallis and post hoc Mann-Whitney test. Results: The differentiation of hDPSCs in all A-PRF groups was significantly different on day-7 (p<0.05) compare to control group (Group I). There were no significant differences between all groups on day-14 (p>0.05). Significantly differences between Group II (1% A-PRF) and Group I (control), Group II (1% A-PRF) and Group III (5% A-PRF), also Group II (1% A-PRF) and Group V (25% A-PRF) was found from post hoc test analysis. Conclusion: The ideal conditioned media concentration for differentiation of human dental pulp stem cells was on 1% up to 5% A-PRF group.

Objective Platelet-rich plasma (PRP) activation is an important factor in triggering the initial release of blood-derived growth factors from platelets. Vascular endothelial growth factor-A (VEGF-A) can be expressed by human dental pulp stem cells (hDPSCs) and plays an important role in dental pulp angiogenesis. The aim of this study is to analyze the effects of calcium gluconate on PRP activation in hDPSC VEGF-A expression. Materials and Methods Two types of PRP and their corresponding activators were analyzed in this study: PRP (activated using calcium chloride/CaCl2) and PRP-T (activated using CaCl2 with the addition of 10% calcium gluconate). hDPSCs were obtained by using an out-growth method (DPSCs-OG), and harvest between the fifth and sixth passages, then cultured in three different media groups: control, PRP, and PRP-T, which were planted in 96 wells (5 × 103 each well). The VEGF-A expression of hDPSCs was analyzed by using an ELISA test and observed at 24, 48, and 72 hours. Statistical Analysis This study was performed by using one-way ANOVA (p < 0.05) test. Results There were significant differences between all groups (p < 0.05) at 48 and 72 hours of observations, and no significant differences in the PRP and PRP-T groups at 48 and 72 hours of observations (p > 0.05). Conclusion PRP and PRP-T were equally effective in inducing VEGF-A expression of hDPSCs.

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