Effect of indentation load and time on knoop and vickers microhardness tests for enamel and dentin

Chuenarrom, Chanya; Benjakul, Pojjanut; Daosodsai, Paitoon

doi:10.1590/s1516-14392009000400016

Cited by 125 publications

(101 citation statements)

References 25 publications

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“…Our values for both mean BHN and KHN are in accordance with previously reported values of dentin microhardness [19, 20]. Moreover, similar to the previous study [7], BioDent RPI technique confirmed that the microhardness of dentin decreased apically toward deep dentin.…”

Section: Discussionsupporting

confidence: 92%

“…The typical indentation patterns obtained from Knoop and BioDent RPI at SD and DD are shown in Figure 2. The standard deviation associated with Knoop hardness numbers showed high variability similar to previous studies [19, 20]. Interestingly, variability was less pronounced in dentin microhardness results obtained by BioDent RPI (Figure 1).…”

Section: Discussionsupporting

confidence: 85%

“…Interestingly, at each location, the BioDent hardness values showed a significant load dependency. These differences are likely due to the indentation size effect (ISE) [20, 21]. There are two types of ISE: 1) normal ISE, a reduction in hardness occurs where indentation load is increased; and 2) reverse ISE, which is associated with increasing hardness when indentation load is increased [20].…”

Section: Discussionmentioning

confidence: 99%

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The interrelationship of microstructure and hardness of human coronal dentin using reference point indentation technique and micro-Raman spectroscopy

et al. 2017

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Objectives The aim of this paper is to determine the interrelationship between the microstructure--in terms of chemical composition and crystallinity--to the microhardness of coronal dentin. Methods Dentin microhardness was tested by a novel reference point indenter and compared to the traditional Knoop hardness method. Micro-Raman spectroscopy was used to determine the chemical composition and crystallinity of dentin. Results From the occlusal groove to the border of the coronal pulp chamber, dentin hardness decreased from superficial dentin (SD) to deep dentin (DD). Mineral/organic matrix ratios (phosphate/C-H and phosphate/amide I) also decreased from SD to DD; however, this change was significant (P<0.05) in the phosphate/amide I ratio only. The phosphate/carbonate ratio decreased significantly by varying position from SD to DD. The degree of the crystallinity, as measured by the full width at half maximum (FWHM) of the peak at 960cm−1, decreased significantly going from superficial to deep dentin. Significance For the first time, the interrelationship between the microstructure and the mechanical properties of coronal dentin was determined by using the novel reference point indentation technique and micro-Raman spectroscopy. We hypothesize that the decrease in hardness from superficial to deep dentin can potentially be explained by decreased mineral content and increased carbonate content, which is also associated with decreased crystallinity. Collectively, there is a positive association between dentin hardness and mineral content and a negative association between dentin hardness and carbonate content.

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Section: Discussionsupporting

confidence: 92%

Section: Discussionsupporting

confidence: 85%

Section: Discussionmentioning

confidence: 99%

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The interrelationship of microstructure and hardness of human coronal dentin using reference point indentation technique and micro-Raman spectroscopy

et al. 2017

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“…Several other factors could have also affected the measured hardness and wear volumes. Variations of enamel hardness values can be expected by factors such as specimen preparation, variation in chemical composition, tooth age, and location in the tooth [68]. E.g., it is known that enamel exhibits highly anisotropic orientation of enamel prism/rods and distribution of hydroxyapatite crystals [21].…”

Section: Relationship Between Hardness and Wearmentioning

confidence: 99%

Hardness, friction and wear studies on hydrogen peroxide treated bovine teeth

Mundra

Mohan

Gwyer

et al. 2015

Tribology International

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“…It should be noted that in both studies the same prescribed values of load and pressing time were applied. The average values of Vickers microhardness given by Chuenarrom et al for both dentin and tooth enamel are much higher than the value of microhardness obtained for Lightdon Splint resin [25]. In fact, from the analysis of these data it can be concluded that the tested material has a lower hardness level than other available resins.…”

Section: Vickers Microhardness Testmentioning

confidence: 57%

The Use of Light-Cured Resin as an Alternative Method of Occlusal Splints Manufacturing – In Vitro Study

et al. 2014

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Background. Temporomandibular disorders are very common nowadays. One of the methods to treat these problems is occlusal splint therapy. Modern materials should be introduced to this treatment. Objectives. The aim of this paper was to evaluate the properties of light-activated urethane dimethacrylate and the quality of the bonds it creates with thermoforming foils. Material and Methods. Thermoforming foils were covered with light-cured resin. A bond was formed between the materials using an adhesive. A coating lacquer was used on the resin as a final preparatory step. Three laboratory tests were run: dye penetrant inspection, a Vickers microhardness test and a linear polymerization shrinkage test. The materials were layered and then cured with a polymerizing lamp emitting light of a wavelength of 400 Nm, according to the manufacturer's instructions. All the occlusal splints were fitted to upper dental arch. The devices had been made in an articulator on specially prepared gypsum models. The results were analyzed statistically using a one-sided binomial test, Spearman's rank-order correlation coefficient and the Friedman ANOVA (p = 0.05). Results. In the dye penetrant inspection, only one sample out of sixty showed the effects of color penetration to the adhesive connection. The dye only penetrated the layer of lacquer coating the resin. The average value of the Vickers microhardness test with a load of F = 50 g applied to the material surface for 30 s was HV 0.05 = 7.43 N/mm

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Effect of indentation load and time on knoop and vickers microhardness tests for enamel and dentin

Cited by 125 publications

References 25 publications

The interrelationship of microstructure and hardness of human coronal dentin using reference point indentation technique and micro-Raman spectroscopy

The interrelationship of microstructure and hardness of human coronal dentin using reference point indentation technique and micro-Raman spectroscopy

Hardness, friction and wear studies on hydrogen peroxide treated bovine teeth

The Use of Light-Cured Resin as an Alternative Method of Occlusal Splints Manufacturing – In Vitro Study

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