scholarly journals Effect of Interimplant Distance and Cyclic Loading on the Retention of Overdenture Attachments

2017 ◽  
Vol 18 (11) ◽  
pp. 1078-1084 ◽  
Author(s):  
Seyed S Shayegh ◽  
Seyed MR Hakimaneh ◽  
Mohammad T Baghani ◽  
Shireen Shidfar ◽  
Farinaz K Kashi ◽  
...  

ABSTRACT Aim The purpose of this in vitro study was to investigate the effect of interimplant distance and cyclic loading on the retention of two locator attachment systems. Materials and methods A total of 72 acrylic resin blocks were fabricated and divided into six groups of six pairs each. Locators of DIO and 3i implant systems were positioned on analogs in three different interimplant distances (19, 23, and 29 mm). The blocks were attached to a universal testing machine, and 1,440 dislodging cycles by the force of 136 N were applied. After 0, 120, 360, 720, and 1,440 cycles, the retention was recorded. Three-way analysis of variance (ANOVA) was used to test for differences in retention between the various combinations of the locator, interimplant distance, and cyclic loadings. Results Interimplant distance was significantly associated with retention, independent of the locator system used, and dislodgement force cycles. Mean retention was significantly higher under the 3i system relative to the DIO system (p < 0.0001). This association varied with both interimplant distance (p > 0.0001) and dislodgement force (p < 0.0001) as well as across the various combinations of distance and cycle (p < 0.0001). Conclusion Interimplant distances could affect the initial retention of locator attachments. There was little difference in retention between distances of 23 and 29 mm across all cycles when both locator systems were combined. Distance of 23mm was associated with superior retention in the DIO system. With regard to the speed of retention decrease, the 23 mm distance was associated with better performance. Clinical significance Interimplant distance could play a significant role in overdenture retention with locator attachments. How to cite this article Shayegh SS, Hakimaneh SMR, Baghani MT, Shidfar S, Kashi FK, Zamanian A, Arezoobakhsh A. Effect of Interimplant Distance and Cyclic Loading on the Retention of Overdenture Attachments. J Contemp Dent Pract 2017;18(11):1078-1084.

2015 ◽  
Vol 1 (1) ◽  
pp. 102
Author(s):  
Pramudya Aditama ◽  
Siti Sunarintyas ◽  
Widjijono Widjijono

Resin akrilik merupakan bahan yang sering digunakan dalam pembuatan basis gigi tiruan. Kelemahan resin akrilik adalah mudah patah. Salah satu cara untuk mengatasi masalah tersebut adalah dengan menambahkan polyethylene (PE) atau glass fiber. Tujuan dari penelitian ini untuk mengetahui pengaruh jenis dan volumetrik fiber terhadap kekuatan transversal reparasi plat resin akrilik. Penelitian ini menggunakan dua puluh lima plat resin akrilik kuring panas berukuran 65 x 10 x 2,5 mm. Subjek dipreparasi untuk membuat jarak 3 mm dan sudut bevel 45o. Subjek dibagi menjadi 5 kelompok, masingmasing kelompok terdiri dari 5 subjek. Kelompok 1 (kontrol) tanpa penambahan fiber, kelompok II dengan penambahan 3,7% v/v PE fiber, kelompok III dengan penambahan 7,4% v/v PE fiber, kelompok IV dengan penambahan 3,7% v/v E-glass fiber, dan kelompok V dengan penambahan 7,4% v/v E-glass fiber. Seluruh plat direndam dalam air destilasi selama satu hari pada suhu 37oC. Pengujian kekuatan transversal plat resin akrilik dengan menggunakan Universal Testing Machine dan data yang didapat dianalisis menggunakan ANAVA dua jalur dengan tingkat kepercayaan 95%. Rerata kekuatan transversal (MPa) reparasi plat resin akrilik yang diperkuat fiber: 3,7% v/v PE fiber (67,77±3,34); 7,4% v/v PE fiber (80,37±8,42); 3,7% v/v E-glass fiber (96,72±5,43); 7,4% v/v E-glass fiber (109,44±4,98); sedangkan reparasi plat resin yang tidak diperkuat fiber menghasilkan kekuatan transversal 56,27±4,7 MPa. Hasil analisis menggunakanANAVA dua jalur menunjukkan variabel jenis dan volumetrik fiber memberikan pengaruh signifikan (p<0,05), sedangkan interaksi antara jenis dan volumetrik fiber tidak berpengaruh signifikan (p>0,05). Uji post hoc Tukey menunjukkan perbedaan signifikan (p<0,05) untuk seluruh kelompok perlakuan. Penambahan E-glass fiber dalam reparasi plat resinakrilik mampu meningkatkan kekuatan transversal lebih tinggi dibandingkan dengan menggunakan PE fiber. Peningkatan volumetrik fiber dapat meningkatkan kekuatan transversal reparasi plat resin akrilik. Effect Of Type And Volumetric Fiber On Transverse Strength Of Acrylic Resin Plate Repair. Acrylic resin is the most common denture base material. A disadvantage of acrylic resin is that it is easily fractured. One way to resolve this problem is by adding polyethylene (PE) or glass fibers. The purpose of this research is to find out about the effect of type and volumetric fiber on transverse strength of acrylic resin plate repaired. The experiment involved twenty five plates of heat cured acrylic with the dimensions of 65 x 10 x 2.5 mm. The speciments were prepared to create a 3 mm gap and 45° bevel. The subjects were divided into 5 groups; each group consisted of 5. Group I (control) was without fiber reinforcement, group II reinforced with 3.7% v/v PE fiber, group III reinforced with 7.4% v/v PE fiber, group IV reinforced with 3.7% v/v E-glass fiber, and group V reinforced with 7.4% v/v E-glass fiber. All plates were soaked in distilled water for one day at 37° C temperature. The plates were tested for transverse strength with Universal Testing Machine and all data obtained were analyzed with two way ANOVA at 95% confidence level. The mean of transverse strength (MPa) of the acrylic resin plate repair reinforced with fiber: 3.7% v/v PE fiber was (67.77±3.34); 7.4% v/v PE fiber (80.37±8.42); 3.7% v/v E-glass fiber (96.72±5.43); 7.4% v/v E-glass fiber (109.44±4.98); while the transverse strength of the acrylic resin plate with no fiber reinforced was 56.27±4.7 MPa. Two way ANOVA analysis shows that type and volumetric fiber had significant effect (p<0.05), while the interaction between type and volumetric fiber had no significant effect (p>0.05). Tukey post hoc test shows significant difference (p<0.05) for all groups. The addition of E-glass fibers in the acrylic resin plate repaired increased the transverse strength higher than that with PE fibers. The increase in volumetric fibers might improve the transverse strength of the acrylic resin plate repaired.


2016 ◽  
Vol 17 (1) ◽  
pp. 8
Author(s):  
Tunjung Nugraheni

Tuntutan masyarakat terhadap tumpatan sewarna gigi semakin tinggi. Pada kasus-kasus tertentu teknik restorasi dengan menggunakan dua bahan restorasi yang berbeda (teknik tumpatan sandwich) diperlukan untuk mendapatkan restorasi yang dapat melekat kuat dan mempunyai estetika yang bagus. Teknik tumpatan sandwich yang sering dilakukan adalah menggunakan semen ionomer kaca dan resin komposit. Penelitian ini bertujuan untuk mengetahui efek perbedaan ketebalan semen ionomer kaca dan resin komposit terhadap kekuatan tekan tumpatan sandwich secara in vitro. Pada penelitian ini digunakan 40 subjek penelitian berupa tumpatan sandwich yang dibuat pada cetakan fiber dengan kavitas berbentuk sHinder dengan diameter 5 mm dan tinggi 5 mm. Semua kavitas ditumpat dengan semen ionomer kaca dan resin komposit dengan teknik sandwich, dengan perbandingan ketebalan yang berbeda. Kelompok I dilakukan penumpatan semen ionomer kaca tipe II dan resin komposit packable dengan perbandingan 1:4, kelompok II dengan perbandingan 2:3, kelompok III dengan perbandingan 3:2, kelompok IV dengan perbandingan 4:1. Selanjutnya seluruh subjek penelitian direndam dalam saliva tiruan pH 6,7 dan disimpan pada suhu 370C selama 24 jam dalam inkubator, kemudian diukur kekuatan tekan menggunakan alat uji tekan Universal Testing Machine. Hasil analisis dengan Anava satu jalur menunjukkan perbedaan ketebalan semen ionomer kaca dan resin komposit mempunyai efek yang bermakna terhadap kekuatan tekan tumpatan sandwich (p < 0,05). Hasil uji LSD rerata kekuatan tekan antar kelompok 1,11,III dan IV berbeda bermakna (p < 0,05), dapat disimpulkan bahwa perbedaan ketebalan semen ionomer kaca dan resin komposit berpengaruh terhadap kekuatan tekan tumpatan sandwich.


2021 ◽  
Vol 6 (1) ◽  
pp. 9-18
Author(s):  
Ken Edinata ◽  
Endah Mardiati

ABSTRAK Kebutuhan braket transparan pada perawatan ortodonti semakin berkembang dengan adanya kebutuhan braket sewarna gigi, terutama wanita yang memerlukan penampilan estetik maksimal. Braket yang lepas dalam perawatan ortodonti perlu direkatkan kembali. Pembersihan landasan braket yang terlepas sehingga dapat direkatkan kembali akan mengurangi biaya yang harus dikeluarkan pasien. Melakukan daur ulang braket haruslah dapatdapat dilakukan tanpa merubah sifat fisik dan ukuran dari braket tersebut. Penelitian ini adalah penelitian eksperimental analitik laboratoris in vitro dengan pendekatan komparatif yang bertujuan untuk melihat perbedaan kuat rekat geser braket keramik yang dibersihkan dengan kloroform selama 20 menit, 40 menit, 60 menit. Sampel yang digunakan dalam penelitian ini adalah 60 buah braket keramik monokristalin  merek Ice Inspire dari Ormco dengan perlekatan mekanik. Pengukuran uji rekat geser menggunakan Instron Universal Testing Machine dan sisa resin menggunakan skor ARI. Analisis statistik dilakukan dengan uji Wilcoxon dan ANOVA. Hasil penelitian menunjukkan terdapat perbedaan bermakna kuat rekat geser braket keramik pasca rekat yang dibersihkan dengan kloroform selama 20 menit, 40 menit, 60 menit dan braket keramik pascarekat yang baru. Simpulan dari penelitian ini bahwa Terdapat perbedaan kuat rekat geser braket keramik yang dibersihkan dengan kloroform selama 20 menit, 40 menit, 60 menit dengan braket keramik yang baru, Semakin lama waktu pembersihan braket keramik dengan kloroform, sisa resin adhesif akan semakin bersih dan mempunyai kuat rekat geser yang lebih tinggi. Terdapat perbedaan sisa resin adesif antara braket keramik pasca rekat yang dibersihkan dengan kloroform yang dilepas kembali dengan braket keramik pasca rekat yang baru.   Kata Kunci : perbedaan kuat rekat geser, kloroform, kuat rekat geser, ARI, braket keramik.                                                                                                    ABSTRACT Transparant bracket needs in orthodontic treatment is become huge caused the needs of tranlucent bracket , especially women who require maximum aesthetic appearance. Debonding bracket in orthodontic treatment need  to reattached.  By Cleaning mesh of bracket so it can be reattached to reduce patient costs . Recycling bracket must can done without changing the physical properties and the size of bracket. This study is an experimental study in vitro analytical comparative approach that aims to see the difference shear strength adhesion to ceramic brackets were cleaned with chloroform for 20 minutes , 40 minutes , 60 minutes . The sample used in this study were 60 pieces of ceramic bracket monokristalin from Ormco Inspire Ice with mechanical retention. Measurement of shear strength test using the Instron Universal Testing Machine and the rest of the resin using ARI scores . Statistical analysis was used  with Wilcoxon test and ANOVA . The results showed there were significant differences in the bracket shear strength rebonding ceramic bracket, which cleaned with chloroform for 20 minutes , 40 minutes , 60 minutes and new rebonding ceramic bracket. Conclusions from this research that There is a difference in the shear strength ceramic brackets  which cleaned using chloroform for 20 minutes , 40 minutes , 60 minutes and with a new ceramic bracket , the longer time cleaning ceramic bracket with chloroform, the rest of the adhesive resin will be clean and have strong adhesion higher shear. There are differences between the residual resin adhesive after adhesive ceramic bracket cleaned with chloroform is released back and the ceramic new bracket rebonding. Key words : 


Author(s):  
Azadeh Hesarkhani ◽  
Farnoush Fotovat ◽  
Fatemeh Saneian ◽  
Hosein Akbari ◽  
Hanif Allahbakhshi

Objectives: This study aimed to compare the retention of cast posts cemented with four types of cements and assess the mode of root fracture following their removal. Materials and Methods: In this in vitro, experimental study, 48 upper central incisors were randomly divided into 4 groups of 12, and were endodontically treated. The fabricated cast posts in each group were cemented with zinc phosphate (Masterdent), glass ionomer (GI; Meron), Meta resin cement, and Panavia SA resin cement. A device was customized for post removal by a universal testing machine similar to WAM X pliers. The retention of cemented posts was measured by the pull-out test in a universal testing machine. Next, the teeth were macroscopically and microscopically inspected regarding the occurrence and sites of catastrophic fracture, cracks, or craze lines. Quantitative and qualitative data were analyzed by ANOVA, and Chi-square test, respectively (P<0.05). Results: ANOVA showed a significant difference in the mean retention of cements (P<0.001). Panavia provided the highest retention (278.6±34.9 N) followed by zinc phosphate (221.9±28.88 N), GI (161.3±60.7 N), and Meta (140.4±66.54 N). There was no significant difference between the groups regarding the pattern of root fracture (P=0.39). However, site and extent of fractures were significantly different among the groups (P<0.05). Conclusion: The conventional cements provided optimal retention and caused less root damage after post removal. Thus, cements providing adequate retention and allowing easier post removal are recommended for use in endodontically treated teeth with a possibility of requiring retreatment.


2021 ◽  
Vol 32 (5) ◽  
pp. 105-113
Author(s):  
Laerte Ohse ◽  
Deborah Stona ◽  
Marília M. Sly ◽  
Luiz Henrique Burnett Júnior ◽  
Ana Maria Spohr

Abstract The purpose was to evaluate, in vitro, the fracture strength of teeth restored with 0.3- or 0.6-mm-thick occlusal veneers made of Vita Enamic® bonded to enamel or dentin. Fifty third molars were allocated into five groups (n=10): Group C - control (sound teeth); Group 0.3E - 0.3-mm-thick occlusal veneers bonded to enamel; Group 0.6E - 0.6-mm-thick occlusal veneers bonded to enamel; Group 0.3D - 0.3-mm-thick occlusal veneers bonded to dentin; Group 0.6D - 0.6-mm-thick occlusal veneers bonded to dentin. After luting with Single Bond Universal and Filtek Z-100, the samples were subjected to fracture strength test in a universal testing machine. The fractures were classified as irreparable and reparable. Data were analyzed with 2-way and 1-way ANOVA (α=.05) followed by Tukey’s test. The teeth restored with 0.3-mm-thick occlusal veneers (2658 N) achieved significantly higher fracture strength compared to the teeth restored with 0.6-mm-thick occlusal veneers (2070 N) (p=0.017). The teeth restored with occlusal veneers bonded to enamel (2648 N) had significantly higher fracture strength compared to the teeth restored with occlusal veneers bonded to dentin (2049 N) (p=0.015). Group C (3355 N) and Group 0.3E (2965 N) did not differ significantly from each other, being the fracture strength significantly higher than the other groups (p<0.05). The fractures were predominantly reparable. The teeth restored with 0.3-mm-thick occlusal veneers achieved higher fracture strength compared to the teeth restored with 0.6-mm-thick occlusal veneers. The supporting substrate influenced the fracture strength, which was higher for the teeth restored with occlusal veneers bonded to enamel.


2013 ◽  
Vol 39 (2) ◽  
pp. 140-147 ◽  
Author(s):  
Omid Savabi ◽  
Farahnaz Nejatidanesh ◽  
Forough Yordshahian

The degree of retention for overdenture attachments depends on design, location, and alignment of supporting dental implants and the type of attachments. The aim of this study was to evaluate the retention of an implant-supported overdenture with different attachment designs. An overdenture was made on an edentulous mandibular model with 2 ITI implants (4.1 × 10 mm) in the symphyseal region. Five specimens of 8 attachment designs with corresponding abutments and superstructures were used: ITI regular Dolder bar with 1 metal clip, ITI regular Dolder bar with cantilever and 3 metal clips, Hader bar with 1 plastic clip, Hader bar with cantilever and 3 plastic clips, Sphero block abutment with Rhein plastic caps (green, white, and pink), and retentive anchor with ITI elliptical matrix. The attachments' housings were interchangeable and fixed into the overdenture through nut and screw. The overdenture attachments were subjected to 8 consecutive pulls on a universal testing machine with a crosshead speed of 50.8 mm/min in the vertical and posteroanterior directions. Analysis of variance and Duncan tests were used to determine differences between mean retention values (α = .05). The highest average value retention was recorded for the ITI Dolder bar with cantilever and 3 metal clips in both the vertical and posteroanterior directions, respectively (P &lt; .05). The Rhein pink caps had the lowest retention in the posteroanterior direction (P &lt; .05). Retention decreased over the course of consecutive pulls for all attachments in both directions. The type, number, and placement of attachments affect the retention of implant-supported mandibular overdentures.


2017 ◽  
Vol 2 (1) ◽  
pp. 40
Author(s):  
Pramudya Aditama ◽  
Erwan Sugiatno ◽  
Muhamad Rifqi Tri Nuryanto

The effect of e-glass fiber volumetric on transverse strength of an acrylic resin denture plate repair. Acrylic resin is the most commonly material for the denture base. A disadvantage of acrylic resin is that it is easily to be cracked. One of the ways to resolve this problem is by adding the E-glass fibers. The purpose of this research was to find out the effect of volumetric E-glass fiber on transverse strength of an acrylic resin denture plate repair. The experiment involved thirty plates of heat cured acrylic with the dimensions of 65 × 10 × 2.5 mm. The specimens were prepared to create a 3-mm gap and 45° bevel. Subjects were divided in to 3 groups, each of which contained 10. Group I (control) was with no fiber reinforcement, group II was reinforced with 3.7vol % E-glass fiber, and group III was reinforced with 7.4 volume % E-glass fiber. All plates were soaked in distillation water for one day at 37 °C. Plates were tested for transverse strength with Universal Testing Machine and all data obtained was analyzed with one way anova at 95% confidence level (α= 0.05). The significant difference was found between the transversal force of acrylic resin plat enforced with fiber and other group without being reinforced with fibers (p<0.05). Group reinforced with 7.4 vol % E-glass fibers showed a significant difference (higher) than the group reinforced with 3.7 volume % fibers. The addition of E-glass fibers in an acrylic resin plate repair material increased the transverse strength. The increase in volumetric fibers might improve the transverse strength of an acrylic resin plate repair material.ABSTRAKResin akrilik merupakan bahan yang sering digunakan dalam pembuatan basis gigi tiruan. Kekurangan dari bahan resin akrilik adalah mudah patah. Salah satu cara yang dapat digunakan untuk mengatasi masalah tersebut adalah dengan menambahkan E-glass fiber. Tujuan untuk mengetahui pengaruh volumetrik E-glass fiber terhadap kekuatan transversal reparasi plat gigi tiruan resin akrilik. Penelitian ini menggunakan tiga puluh plat resin akrilik kuring panas dengan ukuran 65 × 10 × 2,5 mm. Spesimen dipreparasi untuk membentuk jarak 3 mm dan sudut bevel 45°. Subjek kemudian dibagi menjadi 3 kelompok, setiap kelompok terdiri dari 10 plat. Kelompok I (kontrol) tanpa diberikan penguat fiber, kelompok II diperkuat dengan 3,7 vol % E-glass  ber, dan kelompok III diperkuat dengan 7,4 vol % E-glass fiber. Seluruh plat kemudian direndam dalam air destilasi selama satu hari pada suhu 37 °C. Plat resin akrilik kemudian diuji menggunakan Universal Testing Machine untuk mengetahui kekuatan transversal dan data yang didapatkan dianalisis menggunakan Anova satu jalur dengan tingkat kepercayaan 95% (α=0,05). Hasil menunjukkan terdapat perbedaan signifikan antara kekuatan transversal plat resin akrilik yang diperkuat dengan fiber dengan kelompok tanpa diperkuat fiber (p < 0,05). Kelompok yang diperkuat dengan 7,4 vol % E-glass fiber menunjukkan perbedaan signi kan (lebih tinggi) dibandingkan kelompok yang diperkuat dengan 3,7 vol % fiber. Kesimpulan bahwa peningkatan volume dari E-glass fiber dapat meningkatkan kekuatan transversal reparasi plat gigi tiruan resin akrilik.


2018 ◽  
Vol 30 (3) ◽  
pp. 189
Author(s):  
Actara Rahmadita ◽  
Dwi Tjahyaning Putranti

Pendahuluan: Resin akrilik polimerisasi panas (RAPP) merupakan bahan basis gigi tiruan yang paling banyak digunakan, namun memiliki sifat kekuatan tarik dan tekan yang rendah, sehingga diperlukan modifikasi dengan penambahan bahan penguat pada RAPP berupa aluminium oksida (Al2O3) atau alumina. Tujuan penelitian untuk menganalisi pengaruh penambahan aluminium oksida pada bahan basis gigi tiruan RAPP terhadap kekuatan tarik dan tekan. Metode: Jenis penelitian eksperimental laboratoris. Sebanyak 25 sampel berbentuk flat dumbbell shaped berukuran 60x12x3,9 (mm) untuk uji kekuatan tarik dan 25 sampel  berbentuk balok dengan ukuran 10x10x4 (mm) untuk uji kekuatan tekan. Pencampuran bubuk resin-aluminium oksida konsentasi 0,5%, 1,5%, 2,5% dan 3,5% dengan cairan resin dilakukan secara manual. Sampel direndam dalam air dan dimasukkan ke dalam inkubator. Uji dilakukan menggunakan universal testing machine dengan beban 1000N dan kecepatan crosshead 1mm/menit. Data dianalisis dengan uji ANOVA satu arah dan uji LSD. Hasil: Nilai kekuatan tarik kelompok kontrol dan keempat kelompok perlakuan penambahan aluminium oksida 0,5%, 1,5%, 2,5 %, 3,5% berturut turut adalah 50,867 MPa, 47,895 MPa, 45,107 MPa, 42,476 MPa, dan 39,753 MPa; sedangkan nilai kekuatan tekan kelompok kontrol dan keempat kelompok perlakuan penambahan aluminium oksida 0,5%, 1,5%, 2,5%, 3,5% berturut turut adalah 88,267 MPa, 106,085 MPa, 122,283 MPa, 135,367 MPa, dan 156,571 MPa. Penambahan bubuk aluminium oksida pada RAPP dapat menurunkan kekuatan tarik dan meningkatkan kekuatan tekan secara signifikan (p=0,0001 (p<0,05)), seiring dengan meningkatnya jumlah konsentrasi aluminium oksida yang ditambahkan. Simpulan: Penambahan aluminium oksida pada bahan basis gigi tiruan resin akrilik polimerisasi panas berpengaruh terhadap kekuatan tarik dan tekan.Kata kunci: Resin akrilik polimerisasi panas, aluminium oksida, kekuatan tarik, kekuatan tekan. ABSTRACT            Introduction: Heat-polymerised acrylic resin (HPAR) is the most widely used denture base material but has a low tensile and compressive strength thus modification is needed by adding reinforcement in the form of aluminium oxide (Al2O3) or alumina. The research objective was to analyse the effect of adding aluminium oxide on the tensile and compressive strength of HPAR denture base material. Methods: An experimental laboratory research was conducted towards the total of 25 samples in the form of flat dumbbell shape sized 60 x 12 x 3.9 mm for the tensile strength test, and 25 samples in the form of blocks with the size of 10 x 10 x 4 mm for the compressive strength test. The mixture of powdered aluminium oxide resin with the concentrations of 0.5%, 1.5%, 2.5%, and 3.5% with a liquid resin was carried out manually. The sample was then immersed in the water and put in an incubator. The test was performed using a universal testing machine with 1000 N loads and 1 mm/minute crosshead speed. Data obtained were analysed using the one-way ANOVA and LSD test. Result: The tensile strength values of the control group and all four treatment groups added with 0.5%, 1.5%, 2.5%, and 3.5% aluminum oxide were 50.867 MPa, 47.895 MPa, 45.107 MPa, 42.4476 MPa and 39.753 MPa respectively, while the compressive strength values were 88.267 MPa, 106.085, 122.283 MPa, 135.367 MPa, and 156.571 MPa consecutively. Addition of aluminium oxide powder to the HPAR can significantly reduce the tensile and compressive strength (p = 0.0001 (p < 0.05)) along with increasing concentration. Conclusion: Addition of aluminium oxide towards the HPAR denture base affected its tensile and compressive strength.Keywords: Heat-polymerised acrylic resin, aluminium oxide, tensile strength, compressive strength.


Author(s):  
Omkar Eswara Babu Danda ◽  
Lakshman Kumar CH ◽  
Afroz Kalmee Syed ◽  
Dasarathi A ◽  
Haranath Danda

Introduction: The root canal therapy is done with the intention to seal it off from any fluid leaks, thus enhancing the longevity of the therapy. The seal between the obturating material and the dentinal walls of the root surface is done by the endodontic sealer. The sealer is designed in such a way that it has to mould itself with the curves and follow the shapes of the root dentinal wall. Aims: To compare in-vitro the tensile bond strength of four different endodontic sealers to root dentin and Gutterpercha. Methods: Thirty six single ‑ rooted canine and premolar teeth with total apical formation were selected. Working length was determined after the crown portion was cut. BMP was done. Teeth were grouped as Group Ⅰ: MTA‑ based sealer, Group Ⅱ: Bioceramic Sealer, Group Ⅲ: Calcium based sealer, Group Ⅳ: Epoxy resin based (AH Plus sealer). Sealers were manipulated according to the manufacturer protocol. Obtuartion was done using 4% gutta ‑ percha. Later tensile strength test was done on the root slices of 2 mm thickness using universal testing machine. 6 mm in diameter Aluminum cylinders, were stabilized on the gutta–percha with small amounts of wax and were filled with one of the sealers. After setting each sealer, the drops of wax were removed and the tensile bond strengths of all the samples were measured using universal testing machine. The data was analysed using Tukey tests and ANOVA. Results: Among the 4 groups highest bond strength was found in Group Ⅱ (BioRootTMRCS) (P < 0.05) and the least was Group Ⅰ (MTA Fill apex). Conclusion: Bioceramic sealer’s tensile bond strength was highest followed by AH26, Sealapex and MTA‑ based sealer. Keywords: Bond strength; BioRoot TMRCS Sealer; MTA Fill apex; AH Plus Sealer, Sealapex, tensile strength.


2011 ◽  
Vol 250-253 ◽  
pp. 1582-1587 ◽  
Author(s):  
Jiang Xu ◽  
Li Feng Lu ◽  
Hong Wei Yang ◽  
Jin Neng Wang ◽  
Yuan Zhang

The related components of material testing machine (e.g., pressure plate, pressure head, compression bar, etc.) produce distortion in the experiment. It is obviously irrational to use the stroke to replace the specimen displacement, which can’t be measured directly by the extensometer in the destructive test. Therefore, the evolution of specimen displacement, machine displacement and stroke of 45 steel, duralumin alloy and sandstone was analyzed under uniaxial monotonic loading and uniaxial cyclic loading. The results show that the deformation of the related components of universal testing machine, which increases/decreases along with the increase/ decrease of load, can’t be ignored. And there is a good one-to-one correspondence between the machine displacement and the load. It also has nothing to do with the types of specimen materials and the experiments. The relationship of machine displacement and the load can be used to determine the specimen displacement indirectly.


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