Hasil Pencarian  ::  Simpan CSV :: Kembali

"ABSTRAKPengoperasian suatu instalasi pembangkit listrik tenaga termal, baik yang berbahan bakar batubara, minyak bumi maupun energi nuklir, umumnya menggunakan air laut sebagai pendingin. Air pendingin yang masuk kembali ke laut memiliki temperatur di atas temperatur ambien air laut. Masuknya limbah air panas dari kanal pendingin ke laut (thermal pollution) dalam jumlah besar dapat memberikan dampak negatif bagi kehidupan biota laut di sekitarnya. Pengkajian tentang pola sebaran polutan panas dari kanal pendingin pembangkit listrik perlu dilakukan untuk dapat mengetahui luas daerah yang terkena dampak dan berapa besar perubahan temperatur yang terjadi. Simulasi sebaran panas di laut dilakukan dengan mengasumsikan pembangkit listriktenaga nuklir dengan kapasitas 7000 MWe beroperasi di Semenanjung Muria Jepara sebagai calon tapak PLTN di Indonesia. Hasil simulasi menunjukkan temperatur sebesar 34-360C menyebar sejauh 115 m, sementara temperatur sebesar 31-330C menyebar sejauh 1048 m dari outlet kanal pendingin.

---

ABSTRACTThe operation of a thermal power plant, including coal-fired, oil and nuclear energy, use sea water as coolant. Cooling water back into the sea has a temperature above the ambient temperature of sea water. The entry of warm water waste from the cooling canal to the sea (thermal pollution) in large quantities may cause negative impact on marine biota around the canal outlet. Assessment of heat pollutant dispersion pattern from power plant cooling canal needs to be done in order to know the area affected and how much the temperature changes that occur. It is assumed that 7000 MWe nuclear power plant is operated to simulate heat dispersion to ocean water body at Muria peninsula, Jepara as a candidate site of nuclear power plant at Indonesia. The simulation results show that temperature of 34-360C disperse along 115 meters,meanwhile temperature of 31-330C disperse along 1048 meters from cooling canal outlet."

"Objectives: This study was to investigate the effect of a variety of root canal irrigation solutions on flexural strength of dentin. Materials and Methods: Fifty intact, extracted human mandibular third molars were used in this study. Each tooth was sectioned using diamond cutting disc to create dentin bar (1x1 mm, with 7 mm in length). All dentin bars were randomly assigned into 5 groups of 10 each. Group 1, dentin bars were immersed in 5% NaOCL; group 2, in 2.5% NaOCL; group 3, in 15% EDTA; group 4, in 0.2% chlorhexidine gluconate (CHX); and group 5, in saline (as control) respectively. Each group was immersed for 2 hours. Each dentin bar was subjected to a three-point bend using MTS Universal Testing Machine to test the flexural strength. Data were analyzed using one way Anova, followed by Turkey's test performed at the 0.05 level of significance. Results: All irrigation solution have an effect on the flexural strength (P<0.05). EDTA caused the greatest effect on dentin mechanical properties, which revealed the lowest flexural strength (100.64 ± 7.23). In contrast, 0.2% CHX generated the least influence on dentin mechanical properties, which demonstrated the greatest flexural strength (189.85 ± 6.44). Conclusion: Root canal irrigation solution can induce effect on flexural strength of dentin. Chlorhexidine gluconate demonstrates the best irrigation solution since it has a slight effect on dentin mechanical properties, particularly flexural strength."

"The use of instruments, such as files and reamers, to open the orifice and cleaning-shaping procedure, in a curved canal in excess of 20-degree angle without precurving instrument and irrigation may form a ledge in the canal. Treatment failure may result due to an inadequate cleaning at the apical third of the canal. This failure may be prevented by eliminating the ledge-correction of the curved canals. The purpose of this case is to highlight the importance of careful use of endodontic instruments to avoid ledging. Therefore knowledge of tooth morphology and the use of files in curved canals is an important factor."

"Indonesian Journal of Dentistry 2006; Edisi Khusus KPPIKG XIV: 46-50The necrosis tooth wilh incomplete formed roots and wide root canal should be treated by apexification. Gutta-percha combined with root canal sealer is widely used as an obturation material. The aim of this case report is to figure out that the use of customized gutta-percha in wide root canal to produce compact and hermetic filling."

"The aim of this study is to evaluate the effectiveness over application time of different formulations of a novel endodontic irrigant (QMix™ 2in1) composed of a polyaminocarboxylic acid chelating agent, a bisbiguanide antimicrobial agent, a surfactant and deinoized water to remove the root canal smeal layer and expose patent dentinal tubules compared to a standard solution of 17 % EDTA. Eighty human tooth roots from extracted, single-rooted teeth were instrumented (size 40.06) using 0.2 mL of sodium hypochlorite (6.15 %) between each file size with a 3 mL water rinse after final instrumentation. Eight groups of 10 roots were irrigated with 3 mL of different formulations of QMix: QMix A, QMix B, and QMix C, or 17 % or EDTA for 60 and 90 s, respectively, then rinsed with 5 mL of sterile water. The roots were irrigated using a standard irrigation syringe and a 30 ga side-vent needle with an apical-coronal motion to within 1 mm of the working length. The coronal, middle and apical thirds of one canal surface of each root was evaluated at 1000x using scanning electron microscopy. The presence of smeal layer was scored using a 5-point scale. Data were analyzed with the Kruskal-Wallis rank sums test, the Steel-Dwass, all-pairs comparison test, and the Steel method (with control) test. Irrigant type was highly significant (p < 0.007). Combined 60 and 90 s exposure data indicated QMix A (p = 0.014) and QMix C (p = 0.028) were superior to EDTA. While at the 90 s exposure time, smear layer removal by solutions QMix A (p = 0.043), QMix B (p = 0.018), and QMix C (p = 0.011) was superior to EDTA. All irrigants removed smear layer more effectively at the coronal and middle levels compared to the apical level (p < 0.001). Analysis showed all three QMix formulations were superior to EDTA in smear layer removal and exposure of dentinal tubules in the root canal system in single-rooted teeth."

"Visualisasi anatomi saluran akar menggunakan computed tomography tiga dimensi dan preparasi transparan. Computed Tomography (CT) tiga dimensi sedang dikembangkan agar dapat digunakan untuk menganalisis topografi anatomi saluran akar untuk membuat keputusan tentang metode preparasi yang tepat. Analisis bentuk dan ukuran anatomi gigi juga dapat dilakukan menggunakan metode transparan. Penting untuk membandingkan ketepatan hasil analisis dari kedua metode tersebut. Tujuan: Membandingkan akurasi analisis anatomi saluran akar dengan dua metode CT tiga dimensi dan preparasi transparan. Metode: Gigi molar tiga bawah digunakan sebagai sampel analisis. Analisis dengan CT tiga dimensi dilakukan sebelum gigi diekstraksi. Gigi yang selanjutnya diekstraksi tersebut kemudian diolah untuk mendapatkan sediaan transparan. Hasil: Walaupun karakteristik gigi yang berhubungan dengan sudut kemiring mahkota, bentuk kurva mahkota dan devisasi saluran akar dapat terlihat melalui analisis dengan CT tiga dimensi, parameter anatomi gigi yang lain dapat diperlihatkan melalui sediaan transparan. Sediaan transparan dapat memperlihatkan kurva saluran akar secara lebih jelas. Simpulan: Analisis sediaan transparan dapat memberikan gambaran anatomi saluran akar yang sangat jelas dan lebih baik daripada CT tiga dimensi. Analisis dengan CT tiga dimensi dapat memberikan informasi tambahan tentang hubungan gigi di dalam rahang.

---

Three-dimensional Computed Tomography (CT) is used to analyze the topography of the root canal anatomy in order to make a decision in choosing root canal preparation method. There is a method that make extracted teeth transparent maintaining its anatomical shape and size. It is important to compare the accuracy of the two visualization methods. Objective: To compare the transmission accuracy of root canals anatomy by two visualization methods, three-dimensional CT and transparent tooth preparation. Methods: Mandibular third molar was used as sample. The three-dimensional CT scan was performed before extracting the teeth. Then teeth were extracted and placed in solutions that made them transparent. Results: Despite the fact that the character of dental origin in terms of the angle of the crown, the curvature of the crown, the deviation of the root showed in three dimensional CT, other tooth anatomical parameters were equally well detected using a transparent tooth preparation. Overall, the curvature of the root canals is more clearly shown by transparent tooth preparation. Conclusion: Transparent tooth preparation provides superior visualization of real root canal anatomy compared to three-dimensional CT, however the later could give us more information about the relation of the tooth within the jaw."