SIMPLIFIED TECHNIQUE FOR REMOVAL OF PREFABRICATED THREADED POSTS

This paper describes a time-saving procedure for the removal of prefabricated threaded posts. In this technique, a slit is prepared in the head of the post to-be-removed so that it can be engaged by a jewelers’ precision stainless steel flat-blade screwdriver which would drive it out when rotated counterclockwise. This simple technique spares the clinician valuable time and effort during removal, requires minimal or no loss of valuable tooth structure compared to other techniques. It is also conservative in the sense that it does not expose dental tissue to thermal insults from use of ultrasound

PENGARUH INFRASTRUKTUR (JEMBATAN) TERHADAP PEREKONOMIAN DI PROVINSI ACEH

ABSTRAKJudul:Pengaruh Infrastruktur (Jembatan) Terhadap Perekonomian di Provinsi AcehNama:M Rayyan RivaldaNIM:1401101010019Fak./Jurusan:Ekonomi dan Bisnis/ Ekonomi PembangunanDosen Pembimbing: Dr. Eddy Gunawan, M.EcKonsentrasi: Ekonomi Regional dan PerkotaanPenelitian ini bertujuan untuk mengkaji Pengaruh dari Infrastruktur (Jembatan) Kabupaten/Kota di Provinsi Aceh terhadap perekonomian di Provinsi Aceh, dimana infrastruktur akan menyerap tenaga kerja maka dalam penelitian ini terdari dari 1 variable dependen dan 2 variable independen, PDRB sebagai variable dependen dalam penelitian ini sedangkan Panjang Jembatan dan Jumlah Pekerja sebagai variable independent. Berdasarkan model Regresi Linear Berganda, dengan menggunakan data panel dari 23 Kabupaten/Kota di Aceh dari tahun 2011 sampai 2015 dan juga dengan pendekatan Fixed Effect Model (FEM). Hasilnya menunjukkan bahwa pengaruh variable Panjang Jembatan tidak memberikan pengaruh yang signifikan terhadap PDRB Provinsi Aceh sedangkan Jumlah Pekerja memiliki pengaruh positif dan signifikan terhadap PDRB Provinsi Aceh. Kata Kunci: Infrastruktur, Jembatan, PDRB kabupaten/kota, dan Perekonomian di Provinsi Aceh. Fixed Effect Model. ABSTRACTTitle:Effect of Infrastructure (Bridges) on the Economy in Aceh ProvinceName:M Rayyan RivaldaNIM:1401101010019Faculty / Department: Economics and Business / Development EconomicsSupervisor:Dr. Eddy Gunawan, M.EcConcentration: Regional and Urban EconomicsThis study aims to examine the Effect of District / City Infrastructure (Bridges) in Aceh Province on the economy in Aceh Province, where infrastructure will absorb labor, so in this study there are 1 dependent variable and 2 independent variables, GDP as the dependent variable in this study while Bridge Length and Number of Workers as independent variables. Based on the Multiple Linear Regression model, using panel data from 23 districts / cities in Aceh from 2011 to 2015 and also using the Fixed Effect Model (FEM) approach. The results show that the variable effect of Bridge Length does not have a significant effect on the Aceh Province GRDP while the Number of Workers has a positive and significant influence on the Aceh Province GRDP.Keywords : Infrastructure, Bridges, district / city GRDP, and Economy in Aceh Province. Fixed Effect Model

PENERAPAN MODEL PEMBELAJARAN STUDENT TEAM ACHIEVEMENT DIVISIONS DENGAN PERMAINAN EDUKATIF UNTUK MENIGKATKAN KEMAMPUAN BERPIKIR KRITIS DAN HASIL BELAJAR AKUNTANSI SISWA KELAS XI AK SMK SULTAN ISKANDAR MUDA MEDAN TAHUN PEMBELAJARAN 2017/2018

Permasalahan dalam penelitian ini adalah rendahnya kemampuan berpikir kritis dan hasil belajar akuntansi siswa kelas XI AK SMK Sultan Iskandar Muda Medan. Tujuan penelitian ini adalah untuk mengetahui peningkatan kemampuan berpikir kritis dan hasil belajar akuntansi siswa melalui penerapan Model Pembelajaran Student Team Achievement Divisions dengan Permainan Edukatif. Penelitian ini dilaksanakan di SMK Sultan Iskandar Muda yang beralamat jalan Tengku Amir Hamzah pada semester ganjil Tahun Ajaran 2017/2018 dengan subjek siswa kelas XI AK yang berjumlah 34 orang siswa. Penelitian ini merupakan Penelitian Tindakan Kelas (PTK) yang terdiri dari 2 siklus, dimana dalam setiap siklus terdiri dari 4 tahap yaitu perencanaan, tindakan, observasi, dan refleksi. Teknik yang digunakan untuk pengumpulan data dalam penelitian ini menggunakan tes dan observasi. Sedangkan teknik analisis data yaitu dengan data kualitatif dan kuantitatif. Berdasarkan hasil analisis data diperoleh hasil kemampuan berpikir kritis siswa pada siklus I yaitu tidak ada siswa yang memiliki kemampuan berpikir yang sangat kritis, 15 siswa masuk dalam kategori kritis dengan presentase 33%, 28 siswa masuk dalam kategori cukup kritis dengan presentase sebesar 62% dan 2 siswa masuk dalam kategori kurang kritis dengan presentase 5%. Terjadi peningkatan pada siklus II sebanyak 12 siswa dengan persentase 35 % kemampuan berpikir yang sangat kritis, 18 siswa masuk dalam kategori kritis dengan presentase 53%, 4 siswa masuk dalam kategori cukup kritis dengan presentase sebesar 12% dan tidak ada siswa masuk dalam kategori kurang kritis. Sedangkan tes hasil belajar siswa yang dilaksanakan terdapat peningkatan hasil belajar siswa yaitu pada siklus I terdapat 19 siswa (55,88%) yang tuntas menjadi 30 siswa (88,23%) pada siklus II. Sebagai indikator ketuntasan klasikal ditetapkan 75% siswa memperolah nilai ≥ 75. Dari perolehan hasil belajar siswa dan lembar observasi kemampuan berpikir kritis, dapat dismpulkan bahwa penerapan Model Pembelajaran Student Team Achievement Divisions dengan Permainan Edukatif untuk Menigkatkan Kemampuan Berpikir Kritis dan Hasil Belajar Akuntansi Siswa Kelas XI Ak SMK Sultan Iskandar Muda Medan Tahun Pembelajaran 2017/2018 dapat meningkatkan kemampuan berpikir kritis siswa dan hasil belajar akuntansi siswa

Fracture Resistance of computer aided endo-crowns versus conventional endo-supported computer aided full crowns

The purpose of the present study was to investigate the fracture resistance of computer aided endo-crowns versus conventional core-supported computer aided full crowns. Ninety human teeth were collected, 30 for each type (maxillary central incisors, maxillary 1st premolars and maxillary 1st molars). Specimens were divided into 3 groups (n=10) according to restoration used: 1) PC: Post-core and crown; 2) NC: Nayyar core and crown and 3) EC: Endo-crown. Each group was further subdivided into 3 subgroups according to the tooth used: I (Incisor), P (Premolar) and M (Molar). For group PC: Fiber post (Radix, Dentsply Maillefer) were cemented using resin cement (Calibra Dual Cure, Denstply Detrey GmbH). For group NC: 3 mm of gutta percha of every canal was removed. For groups PC and NC, after etching and bonding of root-face, transparent core former (Coltène/ Whaledent) was filled with SDR (Smart Dentine Replacement, Dentsply Detrey GmbH) and inverted onto root-face and cured. All specimens were individually scanned and thermocycled for 1000 cycles then submitted to compression test using universal testing machine (Instron 8874; Instron Corp.) Fracture was confirmed by sudden drop in load readings. Subgroup IPC scored the highest mean among group I and subgroup PNC scored the highest mean among group P. One-Way ANOVA detected significant differences among groups I and M with p\u3c 0.05 in I and M groups. Regarding P group, P-value was \u3e 0.05 indicating no significant differences among group. Endocrown showed the highest fracture resistance means in molars, while Nayyar core and crown showed the highest fracture resistance means in premolars. However, post-core and crown revealed the highest fracture resistance means in incisors

EFFECT OF LIGHT TRANSMITTING ABILITY OF FIBER POST ON BOND STRENGTH OF SELFADHESIVE RESIN CEMENT TO RADICULAR DENTINE

Aim: to investigate the effect of different light transmitting ability of two fiber posts systems on bond strength to the root canal dentine using dual cure self-adhesive resin cement. Materials and methods: 24 freshly extracted human premolars were decoronated and endodontically treated. Post spaces were prepared to a depth of 8 mm and width of 1.3 mm using manufacture’s supplied drills. Teeth were randomly classified into two main groups (n= 12) according to fiber post light transmission ability; group I; non-light transmitting fiber posts (NLT) (Reforpost, Angelus), group II; light transmitting fiber post (LT) (Exacto, Angelus). Both groups were cemented using self-adhesive resin cement (SpeedCEM, Ivoclar Vivadent). Using low speed saw (IsoMet, Buehler), a 2 mm thickness coronal, middle and apical sections were obtained from each sample. Then they were subjected to push out test using Instron machine (Lloyd Instruments Ltd) until failure. Data was collected and statistically analyzed. Results: the highest means in the coronal and middle parts was found, when using light transmitting fiber post, which scored (11.75, 10.30 MPa) compared with (6.51, 6.98 MPa) when using non-light transmitting group. One-way ANOVA among the groups revealed a significant difference between non-light and light transmitting fiber post. However, there is no significant difference on the middle and the coronal parts. Conclusions: There was no significant difference between non-light and light transmitting fiber post when all sections were added together. There is a reasonable doubt regarding the ability of light to reach more than 4 mm depth

A COMPARISON BETWEEN THE EFFECT OF DIFFERENT PRESSURES OF AIR PARTICLE ABRASION BEFORE AND AFTER SINTERING WITH AND WITHOUT ZIRCONIA LINER ON BOND STRENGTH OF RESIN TO ZIRCONIA SURFACE

This study aimed to compare the effect of different pressures of air particle abrasion 2 and 4 bars before and after sintering with and without zirconia liner on SBS of resin to zirconia Surface. Materials and Methods: 54 zirconia cuboids 8×8×3 mm were milled and divided into 6 equal groups (N=9) according to surface treatment; sintered with ceramic liner application and 2 bars pressure (SL2) and with 4 bars pressure (SL4), sintered with no ceramic liner and 2 bars pressure (SN2) and 4 bars pressure (SN4), unsintered with no ceramic liner and 2 bars pressure (UN2) and 4 bars pressure (UN4). Specimens underwent thermocycling (1000 cycles) between 5 ̊ and 55 ̊ Celsius with dwell time of 10 seconds, and submitted to SBS test. Data was statistically analysed. Results: All 4 bars APA groups showed higher SBS than 2 bars groups with significant difference between SL4 group (4.7±2.07) and SL2 group (2.58±1.94). Groups with APA before sintering (12.42±2.56) showed significantly higher SBS than APA after sintering (6.35±3.7). SL2 group showed least SBS with significant difference (2.58±1.94) compared to UN2 (11.83±3.35) and SN2 (7.87±2.12). SL4 group (4.7±2.07) showed the least SBS compared to the UN4 (13±1.38), and SN4 (10.24±2.94) groups. Conclusion: It was found that APA of zirconia surface before sintering yielded superior performance than APA after sintering, also 4 bars APA pressure application showed higher SBS than 2 bars pressure, application and firing of ceramic liner onto zirconia surface didn’t enhance SBS

EFFECT OF LIGHT TRANSMITTING ABILITY OF FIBER POST ON BOND STRENGTH OF SELFADHESIVE RESIN CEMENT TO RADICULAR DENTINE

Aim: to investigate the effect of different light transmitting ability of two fiber posts systems on bond strength to the root canal dentine using dual cure self-adhesive resin cement. Materials and methods: 24 freshly extracted human premolars were decoronated and endodontically treated. Post spaces were prepared to a depth of 8 mm and width of 1.3 mm using manufacture’s supplied drills. Teeth were randomly classified into two main groups (n= 12) according to fiber post light transmission ability; group I; non-light transmitting fiber posts (NLT) (Reforpost, Angelus), group II; light transmitting fiber post (LT) (Exacto, Angelus). Both groups were cemented using self-adhesive resin cement (SpeedCEM, Ivoclar Vivadent). Using low speed saw (IsoMet, Buehler), a 2 mm thickness coronal, middle and apical sections were obtained from each sample. Then they were subjected to push out test using Instron machine (Lloyd Instruments Ltd) until failure. Data was collected and statistically analyzed. Results: the highest means in the coronal and middle parts was found, when using light transmitting fiber post, which scored (11.75, 10.30 MPa) compared with (6.51, 6.98 MPa) when using non-light transmitting group. One-way ANOVA among the groups revealed a significant difference between non-light and light transmitting fiber post. However, there is no significant difference on the middle and the coronal parts. Conclusions: There was no significant difference between non-light and light transmitting fiber post when all sections were added together. There is a reasonable doubt regarding the ability of light to reach more than 4 mm depth

EVALUATION OF AN EXPERIMENTAL SCREW-RETAINED RETRIEVABLE CROWN VERSUS CONVENTIONAL CROWN DESIGN

Statement of problem: Removing cemented crowns is usually a complicated procedure that may lead to irreversible damage to the tooth/crown and mostly necessitate remake of crown with added effort for both patient and clinician. Purpose: This in-vitro study evaluated an experimental two-component, screw-retained retrievable crown design in comparison to the conventional design. Materials and methods: A total of 120 extracted maxillary 2nd premolars received root canal treatment and were divided into two groups (n=60 each) according to the crown design they will receive. Gp CC received a threaded modified post, a composite core and a metal coping, while Gp RC received a two-component retrievable crown design. Fracture resistance was assessed by a 90 degrees vertical load to the center of the occlusal surface, using universal testing machine, under a constant crosshead speed of 0.5 mm/min until failure. Microleakage was assessed by placing specimens in methylene blue dye for 12 hours, sectioning the teeth longitudinally, and then examining the sectioned samples under stereomicroscope. Retrievability testing was conducted by 5 prosthodontists who attempted to uncover and unscrew the posts. Data were statistically evaluated using computer software (SPSS version 17; SPSS Inc.). Results: No significant difference between the 2 designs tested regarding microleakage tests (P=.34) whereas the experimental design, was significantly more resistant to fracture and more retrievable than the conventional one (P\u3e.5). Conclusions: The proposed retrievable crown design showed promising results and may be considered as an option to substitute the conventional design. Further studies are needed to confirm that

Influence of core color on final shade reproduction of zirconia crown in single central incisor situation ? An in vivo study

A lot of shaded zirconia blocks are being introduced into the market. Their effect on the final shade of the restoration is yet uncertain. Twenty-four zirconia crowns were fabricated for 8 patients who needed to restore a single maxillary central incisor, and divided into 3 groups according to the color and type of the zirconia (Zr) used (white Zr core, colored Zr core, and monolithic high translucency (ht) Zr crowns). Using Easyshade spectrophotometer, delta E color difference was calculated between fabricated crown and adjacent tooth. The ?Es obtained were assessed based on 1.6 ?E which represented the color difference that could not be detected by the human eye and considered clinically acceptable. No statistically significant values were found between the 3 groups related to different Zr color and type. Within the limitations of this study, it could be concluded that the shade of the zirconia blank had no significant effect on the final color of the crown. This raises reasonable doubt about the necessity to use colored zirconia blanks or use of dip-in solutions. The clinical implications were that, there was no need to use colored zirconia cores to get more esthetically pleasing restorations with respect to color perception. The use of monolithic high translucent zirconia crowns gained the advantages of high translucency and color reproduction

Influence of resin cement shade on the color and translucency of zirconia crowns

Zirconia crowns are highly attractive for clinicians, although have poor translucency when used as single restorations, in addition to unknown effect of resin cement shade on final cemented crown shade. This study aimed to assess effect of resin cement opacity on color replication potential of different zirconia frameworks with target tooth color, in addition to different zirconia crowns translucency evaluation. Twenty-four zirconia crown restorations were fabricated to restore single central maxillary incisor for 8 patients, divided into 3 groups according to color and type of zirconia used (white Zr core, colored Zr core and monolithic HT Zrcowns). Each group was further subdivided into 2 subgroups according to resin cement shade. Using Easyshade spectrophotometer, Delta E color difference was calculated between each crown parameters using 2 different resin luting cement shades and adjacent target tooth. Translucency parameters (TP) were tested for finished crowns. ?Es obtained were assessed based on ?Eof 1.6 which represented color difference that could not be detected by human eye and considered clinically acceptable. No statistically significant values were found between subgroups related to different resin cement shade. Translucency parameters showed statistically significant different values. Monolithic crowns showed highest translucency parameters followed by Zr crowns on white cores then Zr crowns on colored cores. Resin cement shade didn?t affect final color perception. Monolithic high translucency crowns usage gained advantages of high translucency and delamination prevention. Zirconia crowns could be cemented by opaque or transparent cement without affecting final color