scholarly journals Effect of Insertion and Removal of Tooth Supported Overdentures on Retention Strength and Fatigue Resistance of Two Commercially Available Attachment Systems

Author(s):  
Satyabodh S Guttal ◽  
Sagar Abhichandani

ABSTRACT Purpose The main problem with semiprecision attachment retained prosthesis is that they need frequent servicing in terms of replacing the female component. There is a need for a study to assess the life span and frequency of replacement of elastic components in the attachment systems. Aim The aim of the study was to test the retention strength and fatigue resistance of Rhein OT cap and Ceka sagix attachment systems fabricated on the models. Materials and methods Rhein OT cap (micro) and Ceka sagix attachments were procured. Acrylic resin mandibular models fabricated with teeth embedded at overdenture positions. Bar framework with attachments were cast and cemented on the model. Denture fabricated on this model was subjected to universal testing machine (UTM Instron 5900 series) for retention and fatigue test. The retention strength was measured at various cycles namely 1,440, 2,880, 4,320 and 5,760 cycles to check for the loss of retention and development of fatigue on the basis of average number of removals and placements per day for 1,2,3 and 4 years, respectively. The values of both the attachment systems were recorded at the respective cycles and a graphical analysis was carried out representing the retention loss and development of fatigue. Results One-way ANOVA was used as part of the statistical analysis to compare the retention strength and fatigue resistance of both the attachment systems used. The results obtained proved that the retention values of both the attachment systems on tooth supported overdentures had a significant variation as they were subjected to increased number of cycles. Conclusion Sagix and Rhein attachment systems showed adequate retention values up to the first 2 to 3 years (2,880- 4,320 cycles). Fatigue test simulating 4 years of denture insertion and removal did cause subsequent reduction in the retention values but no component fracture of attachment systems. How to cite this article Guttal SS, Nadiger RK, Abhichandani S. Effect of Insertion and Removal of Tooth Supported Overdentures on Retention Strength and Fatigue Resistance of Two Commercially Available Attachment Systems. Int J Prosthodont Restor Dent 2012;2(2):47-51.

2020 ◽  
Vol 32 (2) ◽  
pp. 91
Author(s):  
Chaterina Diyah Nanik Kusumawardani ◽  
Ronaldo Triputro Chondro ◽  
Ivan Andrian ◽  
Rima Parwati Sari

Pendahuluan: Resin akrilik heat cured (HC) merupakan pilihan utama bahan sebagai basis gigi tiruan. Hidroksiapatit (HAP) adalah molekul kristalin yang sudah banyak digunakan di kedokteran gigi. Penelitian terdahulu membuktikan bahwa HAP mampu mengurangi monomer sisa pada resin akrilik HC, yang akan mengurangi juga porositas resin akrilik tersebut. Berkurangnya porositas resin akrilik, diharapkan akan meningkatkan kekuatan mekanik resin akrilik tersebut. Tujuan penelitian menganalisis pengaruh penambahan hidroksiapatit terhadap porositas dan compressive strength resin akrilik HC. Metode: Jenis penelitian eksperimental laboratoris. Sampel penelitian 20 resin akrilik HC berbentuk silindris (6x3mm), dibagi menjadi 4 kelompok. Kelompok kontrol (tanpa penambahan HAP), kelompok HAP 2%, kelompok HAP 5%, dan kelompok HAP 10%. Permukaan sampel diteliti menggunakan SEM untuk porositasnya. Penghitungan compressive strength sampel menggunakan Universal Testing Machine (load cell 300kg/mm2). Hasil: Uji one-way ANOVA dan Tukey-HSD menunjukkan perbedaan signifikan (p<0,05) antara kelompok kontrol (90±13,5MPa) dengan 5%HAP (105±4,3MPa) dan 10%HAP (113±10,2MPa), begitu pula antara 2%HAP (96±8,4MPa) dengan 10%HAP. Uji SEM menunjukkan tidak adanya reaksi kimia antara HAP dan resin akrilik HC. Tampak pula bercak putih tersebar tidak merata pada permukaan sampel akrilik di kelompok-kelompok perlakuan. Bercak putih ditemukan meningkat sebanding dengan peningkatan konsentrasi HAP, dengan diameter yang semakin besar. Simpulan: Penambahan HAP pada basis resin akrilik HC mampu menurunkan tingkat porositas dan meningkatkan nilai compressive strength. Penurunan tingkat porositas meningkat seiring dengan penambahan HAP. Compressive strength yang paling tinggi didapatkan pada basis resin akrilik heat cured dengan penambahan 10% hidroksiapatit.Kata kunci: Compressive strength, uji SEM, resin akrilik heat cured, hidroksiapatit. ABSTRACT Introduction: Heat-cured acrylic resin has been commonly used as a denture base, whereas hydroxyapatite (HAP) is a crystalline molecule widely used in the field of dentistry. Previous research has been proofed that HAP could reduce the residual monomer of heat-cured acrylic resin, which will reduce the porosity level in advance, so it was expected for better mechanical properties. This research was aimed to analyse the effect of HAP addition towards the porosity level and compressive strength of heat-cured acrylic resin. Methods: An experimental laboratory research was conducted towards 20 cylindrical samples (6 x 3 mm) of heat-cured acrylic resins, which were divided into four groups: Control group (without HAP addition), 2% HAP addition group, 5% HAP addition group, and 10% HAP addition group. Compressive strength was tested using Universal Testing Machine (load cell of 300kg / mm2). Each sample surface porosity was observed using the scanning electron microscope (SEM). Results: One-way ANOVA and Tukey-HSD tests results showed significant differences (p < 0.05) between compressive strength in the control group (90 ± 13.5 MPa) compared to 5% (105 ± 4.3 MPa) and 10% HAP addition group (113 ± 10.2 MPa), significant differences were also shown between the 2% (96±8.4MPa) and 10% HAP addition group. SEM imaging showed that there was no chemical reaction between HAP and heat-cured acrylic resin. It showed uneven white spots in acrylic sample’s surface in all treatment groups. Those white spots were likely to be found more in the higher concentration of HAP, so did the diameter of white spots was also found more in the higher concentration. Conclusion: The addition of hydroxyapatite to the base of heat-cured acrylic resin can reduce the level of porosity and increase the compressive strength value. The decrease in the porosity level increases with the addition of hydroxyapatite. The highest compressive strength is obtained with the addition of 10% hydroxyapatite.Keywords: Compressive strength, SEM imaging, heat-cured acrylic resin, hydroxyapatite.


2020 ◽  
Vol 2 (1) ◽  
pp. 001-011
Author(s):  
Dharma Satya Aprianto ◽  
Zullia Taftyanti

Among various ways to clean the denture based material is by its immersion  in disinfectant solution, such as sodium hypochlorite. Heat polymerized acrylic is denture based material that is easily broken because of its low transverse strength. This study was aimed to observe the transverse strength of denture based material heat polymerized acrylic resin after immersion in sodium hypochlorite. This research used 24 samples of heat cured acrylic resin plates measuring 65 mm long, 10 mm wide and 2.5 mm thick. The samples being divided into 4 groups were immersed in sodium hypochlorite 1% and water for 8 hours and 24 hours in 7 days. The transverse strength of acrylic plate were then  tested using universal testing machine. The measurement results were statistically analyzed employing “one way ANOVA”. The  result showed no significant changes on transverse strength of heat-cured acrylic plate. It was concluded that sodium hypochlorite solution did not provide any significant changes in the transverse strength of heat cured acrylic resin.


2019 ◽  
Vol 8 (1) ◽  
pp. 17
Author(s):  
Sefty Aryani Harahap ◽  
Lasminda Syafiar ◽  
Yosepha Yulinda Esdaria Lubis

Disinfectant by microwave energy is highly recommended as a solution to solve the problem of chemical disinfection on denture bases. One of the denture base materials is heat cured acrylic resin. Aim, to evaluate the effect of disinfectant by microwave energy with different time on the transversal strength of heat cured acrylic resin. 30 plates (n = 6) of heat cured acrylic resin with size 65x10x2,5 mm were divided into 5 groups (control; and microwave energy disinfected for 2, 4 , 6, and 8 minutes with 650 Watts of power). Transversal strength test was carried out using Torsee's Electronic System Universal Testing Machine with a test speed of 0.1 mm / second, and a load cell of 50 kgf. Data analyzed using one-way ANOVA and LSD pos hoc. Results, there were significant differences in the transverse strength among all groups (p <0.05). Mean values of all groups were 103.59 ± 0.66 MPa; 112.02 ± 2.10 MPa; 117.48 ± 1.73 MPa; 125.46 ± 2.25 MPa; and 135.89 ± 1.56 MPa respectively. Conclusion, the longer it is disinfected by microwave energy, the higher the transversal strength of heat cured acrylic resin.


2015 ◽  
Vol 26 (4) ◽  
pp. 390-392
Author(s):  
Ana Paula Perroni ◽  
Érica Alves Gomes ◽  
Amália Machado Bielemann ◽  
Bruna Baseggio ◽  
Leonardo Federizzi ◽  
...  

<p>This study evaluated the tension force of cast frameworks made by the technique of framework cemented on prepared abutments using two different resin cements. Forty multi-unit abutment analogs were individually fixed with chemically cured acrylic resin inside PVC cylinders using a parallelometer. Brass cylindrical abutments were tightened to the multi-unit abutments to be used as spacers and then castable UCLA abutments were positioned above. These abutments were cast with Ni-Cr and then divided into 4 groups (n=10): cemented with RelyX U100(r); cemented with RelyX U100(r) and simulation of acrylic resin polymerization process; cemented with Multilink(r); and cemented with Multilink(r) and simulation of acrylic resin polymerization process. Abutments were cemented according to manufacturers' instructions. In a universal testing machine, tensile strength was applied in the direction of the long axis of the abutments at 1 mm/min crosshead speed until displacement of the luted abutments was obtained. The values of maximum tensile force (N) required for the displacement of the luted abutments were tabulated and analyzed statistically by one-way ANOVA with a 95% confidence level. No statistically significant difference was found among the groups (p>0.05). There was an increase in mean tension force when the specimens were subjected to the simulation of acrylic resin polymerization process, but the results did not differ statistically. Both resin cements presented positive results as regards the retention of luted abutments on their respective multi-unit abutments. Both materials may be indicated for the technique of framework cemented on prepared abutments when professionals pursuit better adaptation of implant-supported frameworks.</p>


2015 ◽  
Vol 26 (3) ◽  
pp. 258-262 ◽  
Author(s):  
Renato Sussumu Nishioka ◽  
Luis Gustavo Oliveira de Vasconcellos ◽  
Renata Pilli Jóias ◽  
Sigmar de Mello Rode

In view of the low loading values commonly employed in dentistry, a load-application device (LAD) was developed as option to the universal testing machine (UTM), using strain gauge analysis. The aim of this study was to develop a load-application device (LAD) and compare the LAD with the UTM apparatus under axial and non-axial loads. An external hexagonal implant was inserted into a polyurethane block and one EsthetiCone abutment was connected to the implant. A plastic prosthetic cylinder was screwed onto the abutment and a conical pattern crown was fabricated using acrylic resin. An impression was made and ten identical standard acrylic resin patterns were obtained from the crown impression, which were cast in nickel-chromium alloy (n=10). Four strain gauges were bonded diametrically around the implant. The specimens were subjected to central (C) and lateral (L) axial loads of 30 kgf, on both devices: G1: LAD/C; G2: LAD/L; G3: UTM/C; G4: UTM/L. The data (με) were statistically analyzed by repeated measures ANOVA and Tukey's test (p<0.05). No statistically significant difference was found between the UTM and LAD devices, regardless of the type of load. It was concluded that the LAD is a reliable alternative, which induces microstrains to implants similar to those obtained with the UTM.


2017 ◽  
Vol 751 ◽  
pp. 657-662
Author(s):  
Phakphum Srinuan ◽  
Jeerapatr O. Baiyokvichit ◽  
Rasana Boonpeng ◽  
Tanapol Wongwisatekit ◽  
Pacharaporn Pattanasukwasan ◽  
...  

The effect of thermoforming on the tear strength of ethylene vinyl acetate (EVA) mouthguard material (Bioplast®) has not been widely investigated. The present study compared the tear strengths of non-processed and processed EVA specimens in various thicknesses. Two groups of EVA sheet (non-processed and processed) in three different thicknesses of 3, 4 and 5 mm were used in specimen fabrication. The processed EVA sheets were achieved by forming the EVA sheet on the cylindrical stone model with the pressure-molding device (Biostar®). Twelve of tear strength specimens of non-processed and processed group in each thickness were prepared following the modified ASTM D 624-00 guideline. The tear strength test was conducted using universal testing machine (Lloyd® 1K series) with the speed of 500 mm/min. The mean thickness and tear strength of the non-processed and processed specimens in each thickness were compared using independent T-test. The differences in the mean tear strength for each thickness of non-processed and process specimens were determined using one-way ANOVA. The mean tear strength and mean thickness of processed EVA specimens was significantly lower than the non-processed EVA specimens for every thickness (P ≤ 0.05). There was no significant difference in the mean tear strength of EVA specimens among each thickness in both non-processed and processed groups. It can be concluded that the thermoforming process has the significant effect on the tear strength of the EVA mouthguard material formed by pressure molding device in every thicknesses. The tear strength of processed specimens were significant lower than the non-processed. Thus, it is more relevant for testing properties of the processed mouthguard material that the mouthguard material before processing.


2006 ◽  
Vol 530-531 ◽  
pp. 605-611
Author(s):  
M.C. Bottino ◽  
D.K. Oyafuso ◽  
Paulo Guilherme Coelho ◽  
Elisa B. Taddei ◽  
Vinicius André Rodrigues Henriques ◽  
...  

The shear bond strength between a ceramic material (Titankeramik®, Vita Zahnfabrik, Germany) and two biocompatible titanium alloys was investigated. Ti-13%Nb-13%Zr (TNZ) and Ti-35%Nb-7%Zr-5%Ta (TNZT) alloys were obtained based on the blended elemental technique followed by a sequence of cold uniaxial and isostatic pressing and sintering. Characterization involved microstructural analysis (SEM) and crystalline phase identification (XRD). Subsequently, samples were machined to 4 x 4 mm with a base of 5 x 1 mm. The base metals were blasted with Al2O3 particles followed by the application of a coupling agent and opaque ceramic. After ceramic firing, the specimens were loaded in a universal testing machine (0,5mm/min). XRD revealed the presence of α and β-phases for TNZ, and peaks related to β phases and Nb and Ta for the TNZT alloy. SEM evaluation (TNZ) depicted remaining pores and biphasic microstructure formation. SEM micrographs of the TNZT alloy revealed good densification and a homogeneous β structure. Shear bond strength data (MPa) were statistically analyzed (one-way ANOVA and Tukey test, α=.05) revealing that TNZT (37.6 ± 2.91) presented significant higher values (p=0.0002) compared to TNZ (26.03 ± 2.92). In conclusion, it seems that Ti alloy composition plays a significant role on ceramic bonding.


2013 ◽  
Vol 24 (3) ◽  
pp. 247-252 ◽  
Author(s):  
Francisca Neta Cruz Soares Sampaio ◽  
Jose Renato Ribeiro Pinto ◽  
Cecilia Pedroso Turssi ◽  
Roberta Tarkany Basting

The aim of this study was to evaluate the effect of sealer application and thermal cycling on the bond strength between tissue conditioners and acrylic resin, and to observe the type of bond failure. Two hundred eighty-eight specimens (10x16x3 mm) were made of an acrylic resin (Lucitone 500, Dentsply) using a metal muffle. Specimens were divided into four groups according to the tissue conditioner (Coe-Comfort, GC or Dentusoft, Densell) used and whether or not a sealer (Eversoft Soft Liner Sealer, Myerson) was applied. Each of the four groups was subdivided into other six subgroups (n=12) to undergo thermocycling for 45, 90, 135, 180 or 210 cycles with a dwell time of 60 s, or to be left non thermocycled (control). Tensile bond strength was measured in a universal testing machine at a crosshead speed of 5 mm/min. Sealant application had no effect on the tensile bond strength of the relined acrylic resin, regardless of the tissue conditioner used (Coe-Comfort: p=0.306 and Dentusoft: p=0.1501). The number of thermal cycles had a significant effect on the tensile bond strength of the relined acrylic resin (Coe-Comfort: p=0.002 and Dentusoft: p<0.001). Both tissue conditioners presented similar bond strength to acrylic resin. For both tissue conditioners, sealer coatings had no influence on bond strength, while different numbers of thermal cycles affected that mechanical property.


2021 ◽  
Vol 15 (2) ◽  
pp. 129-132
Author(s):  
Mohammad Forough Reyhani ◽  
Sheida Hosseinian Ahangarnezhad ◽  
Negin Ghasemi ◽  
Amin Salem Milani

Background. Calcium-enriched mixture (CEM) cement has been introduced and marketed as a biomaterial for use in furcal perforation repair and apexogenesis procedures, in which the compressive strength that indicates the material’s resistance against crushing is of utmost importance. This study evaluated the effect of various liquid-to-powder ratios on CEM cement’s compressive strength. Methods. One gram of the cement was mixed with 0.5, 0.34, and 0.25 mL of demineralized water and transferred to stainless steel molds (6 and 4 mm in height and diameter, respectively). Five cells in the mold were considered for each group. The compressive strength test was conducted using the universal testing machine after incubating for seven days under 95% humidity at 37°C. One-way ANOVA was applied for data analysis at P≤0.05 significance level. Results. The mean compressive strength in the liquid-to-powder ratios of 0.5, 0.34, and 0.25 were 3.4456, 3.2960, and 3.3485, respectively, with no significant differences between them. Conclusion. Under this study’s limitations, changing the liquid-to-powder ratio did not affect CEM cement’s compressive strength.


2018 ◽  
Vol 12 (3) ◽  
pp. 208-212 ◽  
Author(s):  
Mehmet Adiguzel ◽  
Ipek Isken ◽  
Ismail Ilker Pamukcu

Background. The aim of this study was to compare the cyclic fatigue resistance of XP-endo Shaper, HyFlex CM, FlexMaster and Race rotary instruments at body temperature (37±1°C). Methods. Twenty XP-endo Shaper (#30/.01), 20 HyFlex CM (#30/.04), 20 FlexMaster (#30/.04) and 20 Race (#30/.04) instruments were tested at body temperature (n=20). The instruments were evaluated in artificial canals with a 3-mm radius of curvature and 60° angle of curvature to the center of the 1.5-mm-wide canal. Each instrument was rotated until fracture occurred and the number of cycles to failure (NCF) recorded. Data were analyzed using one-way ANOVA and Tukey HSD tests (P<0.05). Results. The difference in the NCF of all the instruments was statistically significant (P<0.05). The order of the instruments from the highest to the lowest NCF was as follows: XP-endo Shaper (3064.0±248.1), HyFlex CM (1120.5±106.1), FlexMaster (569.8±48.4) and Race (445.5±53.5). Conclusion. Under the limitations of the present study, XP-endo Shaper instruments were more resistant to cyclic fatigue than the #30/.04 nickel-titanium rotary instruments immersed in water at simulated body temperature.


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