International Journal of Medical Research & Health Sciences 8(1):71-83. 2019
Co-Cr alloy, PEEK polymer, Bond strength, and Surface treatment
Problem statementA significant clinical concern in Co-Cr alloy removable prosthodontics is a failure of bonding with acrylic resins and PEEK is introduced on various materials to overcome this problem. The reason for this study was to examine the denture base acrylic resin bond strength to Co-Cr alloy and PEEK polymer using different surface treatment. Materials and methodTotal 60 number of disc-shaped specimens were prepared and divided into 2 main groups according to the type of framework material, 30 specimens for Co-Cr alloy and 30 specimens for PEEK polymer, which were then subdivided into 3 groups each one consist of 10 specimens, according to the type of surface treatments. Each group either had a no surface treatment (control group) or air abrasive group (110 μm of alumina oxide) or acid etch (98% sulfuric acid) group. The specimens were thermocycled (3000 cycles) after applications of heat cured acrylic resin. ResultsThe results for Co-Cr alloy showed that the air abrasive surface treatments had the highest bond strength mean value followed by the control group (no surface treatment), while the acid surface treatment had the least mean value of bond strength. For PEEK polymer, the results revealed that the acid surface treatment had the highest value of bond strength followed by the air abrasive surface treatment while the control group (no surface treatment) had the least bond strength mean value. ConclusionAir abrasive surface treatment significantly improved bond strength for both Co-Cr and PEEK, while sulfuric acid treatment show counterproductive result with Co-Cr alloy whereas with PEEK play an important role in bonding mechanism. The use of PEEK framework in combination with heat cured acrylic resin can be recommended as a promising non-metallic alternatives framework material for removable of partial dentures.
Indian Journal of Entomology 80(4):1291-1295. 2018
Pepper powder, piperine, clove oil, Callosobruchus maculatus, green gram, population buildup, emergence, grain damage, mixing, and surface treatment
An experiment was conducted to evaluate the effect of pepper powder, solvent extracted piperine and clove oil against pulse beetle Callosobruchus maculatus in stored green gram at the Post Harvest Technology Center, Bapatla, Guntur District, Andhra Pradesh during 2015 and 2016. There were eleven treatments viz., pepper powder mixed with grain at four different doses i.e., 0.1, 0.2, 0.3 and 0.4% (w/w), pepper powder in sachet @ 1 g and 2 g, cotton swab impregnated with piperine solution @ 3.0% (w/v), plywood piece impregnated with piperine solution @ 1.5% and 3.0% (w/v), plywood piece impregnated with clove oil @ 0.5 ml along with an untreated control. Significant differences were observed among the treatments in population buildup and grain damage due to different doses at exposure times. Grain mixing of pepper powder had a dose response relationship as the adult emergence decreased with dose of from 1 to 4% at all the exposure periods. The mean total emergence and the % grain damage were significantly less in the treatments. Among the pepper treatments, direct mixing of powder with grain was observed to be the most effective over surface placement of piperine extract through plywood pieces or cotton swab.
Indian Journal of Public Health Research & Development 9(11):169-174. 2018
Bond strength, artificial teeth, and Surface treatment
PurposePurpose of the study is to evaluate the effect of pre-processing treatment of ridge-lap surfaces of acrylic teeth, air abrasion, chemical modification or combination of both on the strength of the bond between the teeth and the denture base resin.. Materials and methodTotal of 32 tooth-acrylic resin samples were equally divided into four groups consisting of eight samples each.. The ridge-lap surfaces of each tooth was flattened to the designated level with a tungsten carbide acrylic bur and finished and polished. Ridge lap area of each group was subjected to pre-processing surface treatment like No treatment, air abrasion, chemical application and combination of both respectively. Wax cylindrical specimen of 20 mm X 17 mm dimensions were obtained using PVC pipes. Acrylic teeth were placed on the wax cylindrical specimens and acrylized. All samples were subjected to bond strength evaluation. Shear load testing was carried out in the Universal testing machine. The failure surfaces were subsequently examined under a stereomicroscope. ResultsObtained data was subjected to statistical analysis. The ultimate shear strength value obtained amongst all the test groups was the highest (89.18 Kgf) for Group IV, thereby indicating the effect of combination of air-abrasion and MMA conditioning. Although the highest shear bond strength value seen in Group II (69.56 Kgf) was similar to Group III (69.29 Kgf), yet it was higher than highest value seen in Group I (54.65 Kgf)., ConclusionThere was a significant effect produced on the shear bond strength of the interface when both MMA application and air-abrasion of the ridge-lap surfaces was carried out. When done singly, these modalities showed numerically higher bond strength values but these values were not statistically significant in comparison to the control group in which no treatment was carried out.
Sharma, Sonali, Hegde, Mithra N, and Sadananda, Vandana
Indian Journal of Public Health Research & Development 9(5):265-269. 2018
Aluminium Gallium Arsenide Laser, surface hardness, and surface treatment
AimThe aim of the study was to evaluate microhardness of demineralized enamel following different surface treatment. Materials and method114 extracted intact posterior teeth were selected so to obtain 228 samples. They were sectioned mesio-distally and coated with nail varnish so to obtain windows of 3mm × 3mm. All except control were demineralized by placing in demineralizing solution for 24 hours. The samples were divided into 19 groups of six samples each as follows: 1. Control, 2. Demineralized teeth, 3. Laser 2 watts, 4. Laser 2.5 Watts, 5. Laser 3 watts, 6. Laser 3.5 watts, 7. Laser 4 Watts, 8. Enafix, 9. CPP-ACP F, 10. Laser 2 watts + Enafix, 11. Laser 2.5 Watts + Enafix, 12. Laser 3 watts + Enafix, 13 Laser 3.5 watts + Enafix, 14. Laser 4 watts + Enafix, 15. Laser 2 watts + CPP-ACP F, 16. Laser 2.5 Watts + CPP-ACP F, 17. Laser 3 watts + CPP-ACP F, 18. Laser 3.5 watts + CPP-ACP F, 19 Laser 4 watts + CPP-ACP F.Statistical analysis was done by non-parametric test Kruskal Walis and Mann Whitney and one-way ANOVA test and Post Hoc test for multiple comparison. ResultsThe mean hardness value of controls was 262.87. The demineralized group had the least hardness value (101.50). The hardness values of Laser 3.5 watts followed by application of CPP-ACP F paste was the closet to that of control (245.15). The laser 4 watts and CPP-ACP F combination was next best (244.50). The irradiation of 3.5 watts (235.83) and 4.5 watts (235.87) was just marginally less than the same wattage followed by CPP-ACP F group. ConclusionsAluminium Gallium Arsenide Laser when used in combination with CPP-ACP F brings about statistically significant increase in surface hardness and results are comparable to lasers when used alone. The scores are similar to control tooth.
Mohan, R., Raja, S., Saraswathy, G., Mathivanan, S., and Das, B. N.
International Journal of Engineering Research 2(5):353-356. 2013
rubber, surface treatment, co-efficient of friction (COF), slip resistance, and surface roughness
Rubber and thermoplastic rubber occupies a considerable extent as bottom sole material in shoes. A surface treatment called “halogenation” is offered on these types of soles to improve adhesion strength between upper and outsole. This is a treatment on Thermo plastic Styrenebutadiene-styrene rubber shoe sole (S1) with a 0.5% wt. solution of trichloroisocyanuric acid (TCI) in methyl ethyl ketone (MEK) to introduce chlorinated and oxidized moieties on the rubber surface which modifies the surface of the sole for better adhesion with polyurethane adhesive. This mechanism of surface modification is made use of to improve slip resistance property of the soling material. In this study slip resistance in terms of co-efficient of friction (COF) of untreated and treated soles were measured by a slip resistance tester (Model: SATRA STM 603). The results showed that chlorination treatment made on thermo plastic styrene-butadiene-styrene rubber sole with 0.5% wt TCI produces a noticeable increase in co-efficient of friction values due to increase its surface energy, polarity and surface roughness on the rubber surface.