Abstract. Dental composite as restorative dental materials can be reinforced using ceramic fillers. Homogeneous distribution of filler particles shall improve its mechanical properties. This paper presents the results of the preliminary study on the ZrO 2 -Al 2 O 3 -SiO 2 ceramic fillers made from Indonesian natural sand that can increase the mechanical properties of dental composite. The synthesis was done using zirconium silicate sand (ZrSiO 4 ) and aluminium oxide (Al 2 O 3 ) precursors, which dissolved together with 70:30 weight ratios. Two types of sand were used: (1) manufactured sand (mesh #80) and (2) natural sand (mesh #400). The samples then heated in the furnace at 1100 0 C for 8 hours. The morphological characterization was then evaluated using JEOL Scanning Electron Microscope (SEM) for the surface structure that analyze particles size and distribution. Ceramic fillers made from natural sand is homogenous, well distributed with average particle size of 5-10 μm. Comparably, ceramic filler made from the manufactured sand is heterogeneous, poorly distributed and appear as agglomerates with average particle size are 30-50 μm. The results suggest that ceramic fillers made from natural sand demonstrate better character to represent as a functional restorative dental material.

Tapak dara plant is a plant that contains several active compounds, such as phenolic acids, flavonoids and alkaloids. The tapak dara plant can act as a sedative, urinary laxative, stop bleeding, and neutralize toxins. In addition, tapak dara leaf extract contains ingredients that can act as antifertilization. This study aimed to determine the effect of methanol extract of tapak dara leaf on the estrus cycle of adult female mice (Mus musculus) Balb/C strain. This research is an experimental research by testing cause and effect. The hypothesis test used in this study was one-way ANOVA and BNT test. The significance value of giving tapak dara leaf methanol extract to female mice showed a significant value so that it can be said that the administration of tapak dara leaf methanol extract caused the estrus cycle of female mice to be longer. The significance value of estrogenic activity in mice shows a significant value of 0.047, so it can be said that estrogen activity also affects the length of the estrus cycle. The results of hypothesis testing using the one-way ANOVA test were significant, so it can be concluded that the methanol extract of tapak dara leaves can cause the estrus cycle of female mice to be longer.

Recently, ceramic material has become a main object of scientific interest especially in dental material. The advance of dental materials technology has led to use of zirconia-based ceramics for composite filler. In this study, composite filler has been synthesized from natural zircon sand through geopolymerization method. Composite prototype were made with different filler volume to evaluate mechanical properties including hardness number and diametral tensile strength. Samples divided into two groups with 50 wt% filler volume (group A) and 75 wt% filler volume (group B) which 3 samples for each group. The surface micro hardness of each group tested by Leco M-400-H1 vickers microhardness testing machine and for diametral tensile strength tested using universal testing machine (Lloyd) with crosshead speed of 1,0 ± 0,25 mm/min. The data were analyzed using independent sample t-test. The results showed that the average of hardness number on group A was 13,8 VHN while for group B was 24,1 VHN. The average of diametral tensile strength for group A was 20,461 MPa and 27,689 MPa for group B. Statistical result showed that the value (P<0,05). The conclusion, there is a signifficant difference on the result of hardness test between group A (50 wt% filler volume) and group B (75 wt% filler volume) and also on diametral tensile strength test.