scholarly journals Effect of Trichloromethane on the Bond Strengths between Acrylic Teeth and Different Heat-cured Denture Bases: A Comparative Study

2012 ◽  
Vol 13 (6) ◽  
pp. 850-855
Author(s):  
N Venugopal Rao ◽  
D Lakshmayya Naidu ◽  
JSV Bharat ◽  
M Venugopal Reddy ◽  
P Naveen

ABSTRACT Aim This study is to evaluate the role of 1:1 v/v 30% trichloromethane and monomer solvent in enhancing the durability of bonding between cross-linked acrylic teeth and different heatcured denture bases with or without mechanical preparations made on ridge lap portion of the artificial teeth. Materials and methods Two high impact denture base resin materials (Trevalon HI, DeTrey, UK, and DPI Tuff, Mumbai) and one nonhigh impact denture base resin material (DPI Quick Set, Mumbai) were selected to form three groups. Each group contains 30 specimens prepared by five different methods. A mixture of 30% trichloromethane and monomer, mixed in the ratio of 1:1 and applied for 1 minute on the ridge lap area of experimental specimens of methods—B, C, D and E (Specimens of method—A being control group, where no alterations were made at the ridge lap portion of acrylic teeth) before curing. Hounsfield universal testing machine is employed to evaluate the comparative bond strengths. Results No significant difference was seen in bond strengths between specimens of experimental methods in all groups. When each group was assessed separately method B specimens in group 1 (739.2 N), group 2 (758 N) and method D specimens in group 3 (729 N) showed highest mean bond strengths. Control group specimens showed the least bond strength (400-460 N) in all groups with more adhesive failures. Conclusion Ridge lap portion of the specimens treated with chemical solvent as in method B showed increased bond strength in groups 1 and 2. Hence, this is a preferred method. Clinical significance Evaluation of effect of different chemical and mechanical preparations at the ridge lap areas of acrylic teeth before acrylization helps the clinician and technician to overcome the problem of debonding of teeth from denture bases and in turn provides better quality prosthesis to the patient. How to cite this article Bharat JSV, Naidu DL, Reddy MV, Naveen P, Rao NV. Effect of Trichloromethane on the Bond Strengths between Acrylic Teeth and Different Heat-cured Denture Bases: A Comparative Study. J Contemp Dent Pract 2012;13(6):850-855.

2020 ◽  
Vol 20 (9) ◽  
pp. 5771-5774
Author(s):  
Hyeon Kang ◽  
Min-Kyung Ji ◽  
Hoon-Sung Cho ◽  
Sang-Won Park ◽  
Kwi-Dug Yun ◽  
...  

The purpose of this study was to examine the effect of plasma treatment by treating the surface of Co–Cr alloy, Ti–6Al–4V alloy, and CP–Ti alloy as a material for denture metal frameworks with non-thermal atmospheric pressure plasma (NTAPP) and measuring their shear bond strength (SBS) with a heat-cured resin. 20 specimens were prepared for each of Co–Cr, Ti–6Al–4V, and CP–Ti alloys. Each metal alloy group was divided into the following subgroups depending on NTAPP treatment: C (Co–Cr alloy without plasma), T (CP–Ti without plasma), A (Ti–6Al–4V alloy without plasma), CP (Co–Cr alloy with plasma), TP (CP–Ti with plasma) and AP (Ti–6Al–4V alloy with plasma). Specimens were treated with a metal conditioner and bonded to a denture base resin. SBS was measured using a universal testing machine. All data obtained were statistically analyzed using two-way analysis of variance (ANOVA), Tukey’s honestly significant difference (HSD) test, and independent t-test. The mean values (SD) of SBS (MPa) were: 10.31 (1.19) for C group; 12.43 (0.98) for T group; 13.75 (2.02) for A group; 13.53 (1.61) for CP group; 16.87 (1.55) for TP group; 17.46 (1.65) for AP group. The SBS of the AP group was the highest while that of the C group was the lowest. SBS of specimen treated with NTAPP was significantly increased regardless of metal alloy types (p < 0.001). Within the limitations of this study, NTAPP can increases the SBS of Co–Cr alloy, CP–Ti alloy, and Ti–6Al–4V alloy with a denture base resin.


2016 ◽  
Vol 17 (2) ◽  
pp. 154-159 ◽  
Author(s):  
Farzaneh Ahrari ◽  
Mohammadreza Nakhaei ◽  
Hossein Dashti ◽  
Samaneh Vasigh ◽  
Shazia Mushtaq ◽  
...  

ABSTRACT Aim The aim of this study is to evaluate the effects of three different surface treatments and thermocycling on the tensile strength of a silicone lining material to denture resin. Materials and methods A total of 96 cube-shaped specimens were fabricated using heat-cured polymethyl methacrylate (PMMA) denture base resin. Three millimeters of the material was cut from the midsection. The specimens were divided into four groups. The bonding surfaces of the specimens in each group received one of the following surface treatments: no surface treatment (control group), airborne particle abrasion with 110 μm alumina particles (air abrasion group), Er:yttrium aluminum garnet laser irradiation (laser group), and air abrasion + laser. After the lining materials were processed between the two PMMA blocks, each group was divided into two subgroups (n = 12), either stored in distilled water at 37°C for 24 hours or thermocycled between 5 and 55°C for 5,000 cycles. The specimens were tested in tensile and shear strength in a universal testing machine. Data were analyzed with two-way analysis of variance and Tamhane's post hoc tests (α = 0.05). The mode of failure was determined, and one specimen in each group was examined by scanning electron microscopy. Results Surface-treated groups demonstrated significantly higher tensile strengths compared to the control group (p < 0.001). Nonetheless, no significant differences were found between surface-treated groups (p > 0.05). The tensile strength was significantly different between thermocycled and waterstored specimens (p = 0.021). Conclusion Altering the surface of the acrylic denture base resin with air abrasion, laser, and air abrasion + laser increased the tensile strength. Thermocycling resulted in decrease in bond strength of silicone-based liner to surface-treated acrylic resin. Clinical significance Pretreatment of denture base resins before applying the soft liner materials improves the bond strength. However, thermocycling results in decrease in bond strength of soft denture liner to surface-treated acrylic resin. How to cite this article Nakhaei M, Dashti H, Ahrari F, Vasigh S, Mushtaq S, Shetty RM. Effect of Different Surface Treatments and Thermocycling on Bond Strength of a Silicone-based Denture Liner to a Denture Base Resin. J Contemp Dent Pract 2016;17(2):154-159.


2015 ◽  
Vol 26 (1) ◽  
pp. 50-55 ◽  
Author(s):  
Mansour Rismanchian ◽  
Amin Davoudi ◽  
Elham Shadmehr

Connecting prostheses to the implant abutments has become a concern and achieving a satisfactory retention has been focused in cement-retention prostheses recently. Sandblasting is a method to make a roughened surface for providing more retention. The aim of this study was to compare effects of nano and micro airborne abrasive particles (ABAP) in roughening surface of implant abutments and further retention of cemented copings. Thirty Xive abutments and analogues (4.5 D GH1) were mounted vertically in self-cured acrylic blocks. Full metal Ni-Cr copings with a loop on the top were fabricated with appropriate marginal adaptation for each abutment. All samples were divided into 3 groups: first group (MPS) was sandblasted with 50 µm Al2O3 micro ABAP, second group (NSP) was sandblasted with 80 nm Al2O3 nano ABAP, and the third group (C) was assumed as control. The samples were cemented with provisional cement (Temp Bond) and tensile bond strength of cemented copings was evaluated by a universal testing machine after thermic cycling. The t test for independent samples was used for statistical analysis by SPSS software (version 15) at the significant level of 0.05. Final result showed significant difference among all groups (p<0.001) and MPS manifested the highest mean retention (207.88±45.61 N) with significant difference among other groups (p<0.001). The control group showed the lowest bond strength as predicted (48.95±10.44 N). Using nano or micro ABAP is an efficient way for increasing bond strengths significantly, but it seems that micro ABAP was more effective.


2014 ◽  
Vol 15 (6) ◽  
pp. 688-692 ◽  
Author(s):  
Sukumaran Anil ◽  
Farouk Ahmed Hussein ◽  
Mohammed Ibrahim Hashem ◽  
Elna P Chalisserry

ABSTRACT Objective The purpose of the current in-vivo study was to assess the effect of using 0.12% chlorhexidine (CHX) mouth rinse, before bonding, on shear bond strength of polycarbonate brackets bonded with composite adhesive. Subjects and methods Eighteen orthodontic patients with a mean age 21.41 ± 1.2 years, who were scheduled to have 2 or more first premolars extracted, were included in this study. Patients were referred for an oral prophylaxis program which included, in part, the use of a mouth rinse. Patients were divided into 2 groups, a test group of 9 patients who used 0.12% CHX gluconate mouth rinse twice daily and a control group of 9 patients who used a mouth rinse without CHX, but with same color. After 1 week, polycarbonate brackets were bonded to first premolars with Transbond XT composite adhesive. Premolars were extracted after 28 days and tested for shear bond strength on a universal testing machine. Student's t-test was used to compare shear bond strengths of both groups. Results No statistically significant difference was found in bond strengths’ values between both groups. The test group (with CHX) has mean shear bond strength of 14.21 ± 2.42 MPa whereas the control group (without CHX) revealed a mean strength of 14.52 ± 2.31 MPa. Conclusion The use of 0.12% CHX mouth rinse, for one week before bonding, did not affect the shear bond strength of polycarbonate brackets bonded with Transbond composite. Furthermore, these brackets showed clinically acceptable bond strength. How to cite this article Hussein FA, Hashem MI, Chalisserry EP, Anil S. The Impact of Chlorhexidine Mouth Rinse on the Bond Strength of Polycarbonate Orthodontic Brackets. J Contemp Dent Pract 2014;15(6):688-692.


2015 ◽  
Vol 9 (1) ◽  
pp. 402-408 ◽  
Author(s):  
A.A.R. Khaledi ◽  
M. Bahrani ◽  
S. Shirzadi

Statement of the Problem: Bonding failure between acrylic resin and soft liner material and also gradual loss of soft liner resiliency over time are two impending challenges frequently recognized with a denture base embraced with a resilient liner. Since patients drink various beverages, it is crucial to assess the influences of these beverages on physical characteristics of soft liners. Purpose: This in vitro study envisioned to assess the influence of food simulating agents (FSA) on the hardness of a silicone soft liner by employing a Shore A durometer test and also evaluate its bond strength to a denture base resin by using tensile bond strength test. Materials and Methods: To test the hardness of samples, 50 rectangular samples (40 mm × 10 mm × 3 mm) were prepared from a heat-polymerized polymethyl methacrylate (Meliodent). Mollosil, a commercially available silicone resilient liner, was provided and applied on the specimens following the manufacturer’s directions. In order to test tensile bond strength, 100 cylindrical specimens (30 mm × 10 mm) were fabricated. The liners were added between specimens with the thicknesses of 3 mm. The specimens were divided into 5 groups (n=10) and immersed in distilled water, heptane, citric acid, and 50% ethanol. For each test, we used 10 specimens as a baseline measurement; control group. All specimens were kept in dispersed containers at 37ºC for 12 days and all solutions were changed every day. The hardness was verified using a Shore A durometer and the tensile bond strength was examined by an Instron testing machine at a cross-head speed of 5 mm/min. The records were analyzed employing one-way ANOVA, Tukey’s HSD, and LSD tests. Results: The mean tensile bond strength ± standard deviation (SD) for Mollosil was as follows for each group: 3.1 ± 0.4 (water), 1.8 ± 0.4 (citric acid), 3.0 ± 0.4 (heptane), 1.2 ± 0.3 (50% ethanol), and 3.8 ± 0.4 (control). The hardness values for each group were: 28.7 ± 2.11 (water), 33.2 ± 2.82 (citric acid), 39.2 ± 4.8 (heptane), 32.3 ± 3.56 (50% ethanol) and 22.2 ± 2.08 (control). Mean values for hardness indicated that all of the food simulating agents significantly increased hardness of the Mollosil soft liner compared to the control group (p<0.05). The results of tensile bond strength depicted that water and FSA decreased the bond strength of the soft liner -denture base resin compared to the control group and it was statistically significant (p<0.05). Conclusion: The food simulating agents could influence the mechanical properties of silicone soft liners; hence, clinicians should inform their patients concerning their possible adverse effects and complications.


Author(s):  
Sara T. Alzayyat ◽  
Ghadah A. Almutiri ◽  
Jawhara K. Aljandan ◽  
Raneem M. Algarzai ◽  
Soban Q. Khan ◽  
...  

Abstract Objective The aim of this study was to evaluate the effects of the addition of low-silicon dioxide nanoparticles (nano-SiO2) on the flexural strength and elastic modulus of polymethyl methacrylate (PMMA) denture base material. Materials and Methods A total of 50 rectangular acrylic specimens (65 × 10 × 2.5 mm3) were fabricated from heat-polymerized acrylic resin. In accordance with the amount of nano-SiO2, specimens were divided into the following five groups (n = 10 per group): a control group with no added SiO2, and four test groups modified with 0.05, 0.25, 0.5, and 1.0 wt% nano-SiO2 of acrylic powder. Flexural strength and elastic modulus were measured by using a 3-point bending test with a universal testing machine. A scanning electron microscope was used for fracture surface analyses. Data analyses were conducted through analysis of variance and Tukey’s post hoc test (α = 0.05). Results Compared with the control group, flexural strength and modulus of elasticity tended to significantly increase (p ˂ 0.001) with the incorporation of nano-SiO2. In between the reinforced groups, the flexural strength significantly decreased (p ˂ 0.001) as the concentrations increased from 0.25 to 1.0%, with the 1.0% group showing the lowest value. Furthermore, the elastic modulus significantly increased (p ˂ 0.001) at 0.05% followed by 1.0%, 0.25%, 0.5%, and least in control group. Conclusion A low nano-SiO2 addition increased the flexural strength and elastic modulus of a PMMA denture base resin.


2016 ◽  
Vol 17 (4) ◽  
pp. 322-326 ◽  
Author(s):  
M Kalavathi ◽  
Mallikarjuna Ragher ◽  
G Vinayakumar ◽  
Sanketsopan Patil ◽  
Aishwarya Chatterjee ◽  
...  

ABSTRACT Objective The objective of this study was to evaluate and compare changes in the flexural strength of heat-cured denture base resins when treated using denture cleansers. Study design A total of 40 specimens with dimension 65 mm length, 10 mm width, and 3 mm thickness were prepared as per ISO 1567 specification. A total of 10 specimens were immersed in distilled water to be used as control. Of the remaining 30 samples, 10 were treated with Clinsodent, 10 with VI-Clean, and 10 with Clanden denture cleansers. Specimens in each group were subjected to three-point flexural load in universal testing machine at a cross-head speed of 5 mm/min. The peak load (N) was recorded and flexural strength was calculated. The findings were analyzed using Kruskal–Wallis analysis of variance and Mann–Whitney test. Results Heat-cured denture base resin selected for this study showed significant difference in flexural strength after immersion in denture cleansers Clinsodent, VI-Clean, and Clanden solutions, when compared with the control group. Conclusion Findings of this study showed that denture cleansers altered the flexural strength of heat polymerized acrylic resins that endured soaking cycles which simulated 180 days of use. Hence, denture cleansers should be used with caution, once a day after brushing the dentures. It is advisable for patients to follow the manufacturer's instructions. How to cite this article Ragher M, Vinayakumar G, Patil S, Chatterjee A, Mallikarjuna DM, Dandekeri S, Swetha V, Pradeep MR. Variations in Flexural Strength of Heat-polymerized Acrylic Resin after the Usage of Denture Cleansers. J Contemp Dent Pract 2016;17(4):322-326.


2018 ◽  
Vol 17 ◽  
pp. 1-9 ◽  
Author(s):  
Etiene Faria Aguiar ◽  
Rafaella Tonani ◽  
Fabiana de Goes Paiola ◽  
Michelle Alexandra Chinelatti ◽  
Carolina Noronha Ferraz de Arruda ◽  
...  

Aim: The aim of this study was to evaluate the bond strength of artificial teeth to different types of denture base resins when submitted to thermomechanical cycling (TMC). Methods: Sixty artificial mandibular first molars (Trilux, Vipi) were randomly divided into 3 groups according to denture base acrylic resins (Vipi Wave, Vipi Cril, and Vipi Cril Plus, Vipi). The teeth were fixed onto self-polymerizing acrylic resin bars (0.5 cm2 cross-section x 2 cm height), and the set was included in a metal flask using dental stone/silicone. After the dental stone was set, the bar was removed, and the denture base resin was packed and processed according to the group studied (Vipi Wave: 180 W/20 minutes + 540W/5 minutes; Vipi Cril and Vipi Cril Plus: Water bath at 74ºC for 9h). After polymerization, the samples were divided into 2 groups (n=10), according to the TMC treatment received (simulation of 5 years of mastication or not). The samples were submitted to tensile bond strength test (1 mm/min), and the data (MPa) were statistically analyzed (2-way ANOVA, Bonferroni, α=0.05). The fracture interfaces were evaluated using a stereomicroscope (50x). Results: The bond strength results showed no statistically significant difference (p>0.05) between the resins studied. TMC was significant (p<0.05), demonstrating lower values for the bond strength of artificial teeth to Vipi Cril Plus. The predominant fracture type was cohesive in resin. Conclusions: It was concluded that there is no difference in bond strength between artificial teeth and the resins used for denture base. However, TMC decreases the bond strength values of artificial teeth and crosslink thermo-polymerizable acrylic resin.


Author(s):  
Tahereh Ghaffari Gharebagh ◽  
Fahimeh Hamedirad ◽  
Keyvan Miruzadeh

Objectives: The present study aimed to evaluate the bond strength of heat-cure denture base resin to newly designed Iranian artificial acrylic teeth. Materials and Methods: In this in-vitro experimental study, shear bond strengths of Ivoclar acrylic, Apple composite, and B-Star nanocomposite teeth to heat-cure acrylic denture base resin were compared. A total of 18 samples were selected from each group of teeth. The samples were attached to heat-cure resin according to ISO 10477 standard. For the assessment of bond strength, the samples were placed in a universal testing machine and were subjected to shear forces at a speed of 1 mm/minute to record the fracture load. Descriptive statistics, including frequency, mean, and standard deviation, were calculated using SPSS 20 software. Two-way analysis of variance was used to compare the shear bond strength of the groups with and without monomers and the studied artificial teeth. Results: The mean shear bond strengths of Ivoclar acrylic teeth were 392.22±23.76 MPa and 337.11±32.18 MPa with and without adding monomers to the tooth surface, respectively. The mean shear bond strengths were 250.44±29.84 MPa and 238.33±27.28 MPa (without monomers) and 438.33±24.16 MPa and 311.56±32.78 MPa (with monomers) for Apple composite and B-Star nanocomposite artificial teeth, respectively. Conclusion: The greatest shear bond strength was attributed to Ivoclar acrylic teeth followed by Apple composite and B-Star nanocomposite artificial teeth. Addition of monomers to the tooth surface significantly strengthened the shear bonding of acrylic base resin to the teeth.


2020 ◽  
Vol 11 (SPL4) ◽  
pp. 446-449
Author(s):  
Yu-Ri Choi ◽  
Min-Kyung Kang

Candida albicans (C. Albicans) is one of the bacteria that reside in the oral cavity, and the ones living in medical and commercial denture resins, commonly cause diseases. Therefore, this study was conducted to confirm the antibacterial activity of C. Albicans using a denture base resin containing peony extract with antibacterial properties. Contact angle measurements and color change measurements were performed to confirm the physical change of the material added with the antibacterial agent to the denture reline resin. As a result of the antibacterial test, the experimental group exhibited antibacterial activity against C. Albicans. Compared to the optical density results, the results of the experimental group showed a significant difference. As a result of Fluorescent images showing (confocal laser microscope), the control group showed a lot of live bacteria, and no bacteria appeared in the experimental group. All group  did not show any physical changes. As a result of the contact angle measurement, the surface of the experimental group was changed to hydrophilic. In addition, there was no change in the color of the denture reline resin containing peony extract. In conclusion, it was confirmed that the peony extract contained antibacterial activity of the denture resin, and further studies should be conducted on various bacteria for denture base resin disinfection.


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