scholarly journals Effect of Sealant Application and Thermal Cycling on Bond Strength of Tissue Conditioners to Acrylic Resin

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.

2020 ◽  
Vol 14 (02) ◽  
pp. 268-273
Author(s):  
Sareh Habibzadeh ◽  
Arman Omidvaran ◽  
Solmauz Eskandarion ◽  
Ahmad Reza Shamshiri

Abstract Objectives This study aimed at assessing the effect of the addition of silver nanoparticles (SNPs) to a silicone soft liner on its tensile bond strength to denture base resin. Materials and Methods SNPs were added to Mucopren cold cure soft liner in 0 (control), 0.5, 1, 2, and 3 wt% concentrations and bonded in 120 stainless steel molds with processed heat cure acrylic resin blocks. Liner/resin combination samples were divided into two groups. The first half was stored for 2 days in distilled water at 37°C and then subjected to tensile bond strength, while the other half were thermocycled 3000 times before testing. Mean bond strength, expressed in mega pascals (MPa), was determined in the tensile test with the use of a universal testing machine at a crosshead speed of 5 mm/min. Statistical Analysis Data were analyzed using SPSS via one-way analysis of variance test, t-test, and Tukey’s posthoc, at a 95% confidence level (p < 0.05). Results Addition of SNPs and thermocycling both caused a significant reduction in the tensile bond strength of Mucopren to acrylic resin; however, in the thermocycled group, the bond strength increased with the increase in the concentration of SNPs (p < 0.001). Conclusion Addition of SNPs to Mucopren soft silicone liner reduces its tensile bond strength to denture acrylic resin.


2011 ◽  
Vol 492 ◽  
pp. 18-23
Author(s):  
Xin Yi Zhao ◽  
Shi Bao Li ◽  
Xu Gong

To evaluate the effects of specimen grips on the measurement of the micro-tensile bond strength (mTBS) to dentin. Methods: Twelve extracted human molars were sectioned to expose mid-coronal dentin. Each surface was ground with 600-grit SiC paper. Four adhesives: Prime & Bond NT (Dentsply, USA), Contex (DMG, German), Adper Prompt (3M/ESPE, USA) and Clearfil S3Bond (Kuraray, Japan) were applied to the polished surfaces followed by creation of composite buildups. After 24 hr storage in 37°C water, the teeth were sectioned perpendicular to the adhesive interface to produce multiple beams of composite-bonded dentin, approximately 0.8 mm2in cross-sectioned area. Half of the specimens were attached to testing grips A which did not contain positioning pins and another half were attached to the testing grips B which contained positioning pins. All specimens were tested using a universal testing machine at a crosshead speed of 1.0 mm/min. Results: Specimens tested using the grips A presented lower mTBS than using the grips B (P<0.01). Many specimens tested using the grips A showed mix failure or cohesive failure within composite, and most of the failures were adhesive for specimens tested using the grips A. Conclusion: Specimen grips without positioning pins cannot accurately present mTBS and the grips with positioning pins can more accurately present mTBS.


2015 ◽  
Vol 18 (6) ◽  
pp. 1183-1187 ◽  
Author(s):  
Marcelo Coelho Goiato ◽  
Daniela Micheline dos Santos ◽  
Rodrigo Antonio de Medeiros ◽  
Aljomar José Vechiato Filho ◽  
Mário Alexandre Coelho Sinhoreti ◽  
...  

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.


2012 ◽  
Vol 13 (5) ◽  
pp. 607-611 ◽  
Author(s):  
GS Chandu ◽  
Dayanand Ashok Huddar ◽  
MN Hombesh ◽  
B Sandhyarani ◽  
Girish Shankar Nanjannawar

ABSTRACT Aim Evaluating effects of a denture cleanser on weight, surface roughness and tensile bond strength on two resilient lining materials. Materials and methods Specimens of heat cure acrylic resin were prepared to verify weight change, surface roughness and tensile bond strength. Specimens were divided into four groups: Relined with resilient liner Visco-gel, soft liner immersed in Clinsodent denture cleanser and water and evaluated immediately, 24 hours, 7 and 15 days. Weight changes, roughness and tensile bond strength were determined and data submitted to statistical analysis. Results Visco-gel specimens immersed in water (group 1) have shown significant increased surface roughness than those immersed in Clinsodent (group 3) during 24 hours, 7 and 15 days. The soft liner specimens immersed in water (group 2) have shown increased surface roughness than those immersed in Clinsodent (group 4) during 24 hours and 7 days. Visco-gel specimens immersed in water have shown significant increased tensile bond strength during 7 and 15 days than those immersed in Clinsodent. The soft liner specimens immersed in water have shown increased tensile bond strength than those immersed in Clinsodent during immediately, 24 hours and 7 days. Conclusion Within limitations of this study, specimens immersed in Clinsodent demonstrated increased weight changes compared with water. Specimens immersed in water demonstrated lesser surface roughness and tensile bond strength compared with specimens immersed in Clinsodent. Clinical significance Resilient denture liners and denture cleansers are most commonly used materials in prosthodontics. Caution should be taken while selecting the materials which cause the detrimental changes on properties of the materials. How to cite this article Huddar DA, Hombesh MN, Sandhyarani B, Chandu GS, Nanjannawar GS, Shetty R. Effect of Denture Cleanser on Weight, Surface Roughness and Tensile Bond Strength of Two Resilient Denture Liners. J Contemp Dent Pract 2012;13(5):607-611.


2004 ◽  
Vol 18 (3) ◽  
pp. 271-275 ◽  
Author(s):  
Patricia Ramos Lloret ◽  
Kátia Martins Rode ◽  
Míriam Lacalle Turbino

The use of argon laser (488 nm) has been suggested as a new alternative for polymerizing adhesive materials. This study aimed to evaluate the tensile bond strength of a microfilled composite (A110, 3M) inserted by incremental technique (3 increments of 1 mm) and by single increment (3 mm) polymerized by argon laser for 10, 20 and 30 seconds and halogen light for 40 seconds. Eighty (8 groups of 10 teeth) freshly extracted bovine teeth were stored in a freezer in distilled water for one week. The crowns were cross-sectioned from the roots. Pulpectomy was performed and the pulp chambers were sealed with wax. The buccal surfaces of the teeth were ground with wet sandpaper (grains: 120, 400, and 600) to expose the surface dentin, and the teeth were then included in acrylic resin. A metal device was used to fix each sample and a black propylene matrix25 (3 mm high with an internal millimetric delimitation) was used to insert the material according to the groups studied. The polymerization intervals were of 10, 20 and 30 seconds for the laser polymerization and 40 seconds for the conventional polymerization. Tensile tests were performed by a Universal Testing Machine 4442 (Instron) at a speed of 0.5 mm/min and 500 N load. According to the methodology used, the incremental technique increased bond strength values. There was no difference between the studied polymerization techniques when resin was filled in 3 increments.


2007 ◽  
Vol 18 (2) ◽  
pp. 124-128 ◽  
Author(s):  
Wanessa Christine Souza-Zaroni ◽  
Letícia Caliento Seixas ◽  
Juliane Cristina Ciccone-Nogueira ◽  
Daniela Thomazatti Chimello ◽  
Regina Guenka Palma-Dibb

The aim of this study was to assess the tensile bond strength of four adhesive systems to enamel and dentin: Clearfil Liner Bond 2V - C, Prime&Bond NT/NRC - PB, Single Bond - SB and All Bond 2 -AB. For such purpose, 40 sound human molars were selected. Crowns were bisected in a mesiodistal direction and each half was ground until flat enamel (E) or dentin (D) surfaces were obtained. A total of 80 specimens were randomly assigned to 4 groups (n=20, 10 in enamel and 10 in dentin). After surface treatment, a composite resin (Z250; 3M) cone was prepared using a split Teflon® matrix. Bond strength was tested in an universal testing machine (0.5 mm/min). Bond strength means in MPa were: C - E: 18.66 (±2.67) and D: 21.62 (±5.29); PB - E: 18.13 (±2.96) and D: 3.19 (±1.40); SB - E: 20.06 (±6.11) and D: 16.95 (±2.57); AB - E: 18.20 (±3.94) and D: 15.94 (±4.72). Statistical analysis of data by two-way ANOVA showed that C presented the best results followed by SB. In conclusion, among the tested materials, Clearfil Liner Bond 2V self-etching primer adhesive syetem had the best performance. The substrate type influenced bond strength, being higher to enamel.


Author(s):  
Mohammadreza Nakhaei ◽  
Amirtaher Mirmortazavi ◽  
Mansooreh Ghanbari ◽  
Zahra Ahmadi

Objectives: To evaluate the effect of ozone and two common denture cleansers on the surface hardness and bond strength of a silicone-based soft liner to acrylic denture base material. Materials and Methods: Sixty cylindrical specimens were fabricated using heat-cured poly-methyl methacrylate denture base resin. Three millimeters of the material was ground from the midsection and filled with the soft liner. The resilient liner specimens (n=40) used for the hardness test were 10 mm in diameter and 5 mm in height. Cylindrical and disc-shaped samples were randomly divided into four groups (37°C distilled water, Corega® tablets, 0.5% sodium hypochlorite (NaOCl), and a home ozone generator). To simulate six months of denture cleansing clinically, samples were placed in their cleanser once a day for six months according to the manufacturer’s instructions. All cylindrical specimens were placed under tension until failure in a universal testing machine at a crosshead speed of 5 mm/minute. For disc-shaped samples, hardness was measured using a Shore-A durometer. The results were analyzed using Kruskal-Wallis test, analysis of variance (ANOVA), and Tukey's post hoc test. Results: The mean tensile bond strength was not significantly different among the studied groups (P>0.05). The mean hardness in the ozone and Corega tablet groups was significantly lower than that of the control and NaOCl groups (P<0.05). Conclusion: The type of denture cleanser does not affect the tensile bond strength of silicone soft liners. Home ozone generators and cleansing tablets have less effect on the hardness of soft denture liners compared to 0.5% NaOCl.


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.


2015 ◽  
Vol 63 (1) ◽  
pp. 25-32
Author(s):  
Alcir ROSOLEN ◽  
Enrico Coser BRIDI ◽  
Roberta Tarkany BASTING

OBJECTIVE: The aim of this study was to evaluate in vitro the shear bond strength of metallic orthodontic brackets to enamel using different bonding materials followed by thermal cycling. METHODS: A fluid composite resin (Transbond XT / 3M Unitek) and a resin-modified glass ionomer (Fuji Ortho LC / GC America Inc.) were evaluated. Eighty sound human premolars were randomly divided into eight experimental groups (n = 10), according to the material used and the number of thermal cycles: zero, 1000, 2000 and 3000 cycles. Bracket bonding was performed on the buccal surface of the teeth. After 24 hours, they were subjected to thermal cycling at temperatures ranging between 5° C and 55° C for 15 seconds each immersion. Shear bond strength was performed using a universal testing machine with a chisel-type tip at a speed of 0.5 mm / min. The bond strength data was analyzed using two-way ANOVA. RESULTS: No difference on shear bond strength was observed regarding the number of thermal cycles for each specimen (p = 0.873). A significant difference was found in shear bond strength between the bonding materials (p = 0.022), with significantly higher values for Transbond XT regardless of the number of thermal cycles. CONCLUSION: The number of thermal cycles did not significantly affect the bond strength of the adhesive materials investigated. The bonding agent Transbond XT showed higher bond strength than Fuji Ortho LC regardless of the number of thermal cycles.


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