Structural and Dielectrical Properties of Sterilized Human Teeth

Eissa,

doi:10.3844/pisp.2012.22.27

Cited by 4 publications

(3 citation statements)

References 11 publications

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“…Some attempts have been made to obtain information about the dielectric properties of human teeth (Eissa, El‐Shamy, & Hanafy, ; Mumford, ; ), but the information is still not complete. From the results presented in this work, dentin accumulates and preserves the implanted negative charge longer than enamel does.…”

Section: Discussionmentioning

confidence: 99%

The SEM electron‐mirror effect in human tooth and synthetic hydroxyapatite samples

Reyes‐Gasga¹,

Rodríguez-Torres

Vargas-Becerril³

et al. 2018

Microscopy Res & Technique

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The characteristics of the electron-mirror effect (EME) image depend on both the scanning electron microscope parameters and the sample's physical properties. The behavior of human tooth (dentin and enamel) and synthetic hydroxyapatite samples submitted to the EME procedure is presented in this work. Polyethylene terephthalate (PET) and epoxy resin, two good EME producers, were used for comparison. A distorted EME image was observed in the obtained dentin's surface, but enamel and synthetic hydroxyapatite surfaces did not produce the EME. After ex situ calcination treatments of the teeth at 700 and 1,200 C, the EME was observed in dentin, enamel, and synthetic hydroxyapatite, but highly deformed EME images were produced. We show that these last observations are the result of the well-known charge-edge effect. After EME analysis, the calculated dielectric constant was 8.7 for dentin and 3.8 for PET. Research Highlights• Electron-mirror effect (EME) was observed in dentin but not in enamel or synthetic hydroxyapatite.• Highly deformed EME images are produced in all samples after calcination at above 700 C.• For dentin the calculated dielectric constant was 8.7 and for PET is was 3.8. K E Y W O R D Scharge effect, dentine, dielectrics, electron mirror effect, enamel, SEM

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Section: Discussionmentioning

confidence: 99%

The SEM electron‐mirror effect in human tooth and synthetic hydroxyapatite samples

Reyes‐Gasga¹,

Rodríguez-Torres

Vargas-Becerril³

et al. 2018

Microscopy Res & Technique

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“…Although studies claim that composite resins have low thermal conductivity [18,19], the results of studies that have examined thermal effects on the pulp are difficult to quantify and compare, given the multitude of variables included (thermal source, intensity, duration of action, etc.) [20].…”

Section: Introductionmentioning

confidence: 99%

A Finite Element Method Study on a Simulation of the Thermal Behaviour of Four Methods for the Restoration of Class II Cavities

Staicu,

Țuculină,

Cumpătă

et al. 2024

JFB

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The possibility of dental pulp damage during dental procedures is well known. According to studies, during finishing and polishing without cooling, temperatures of up to 140 °C or more can be generated. There are many studies that have analysed the influence of the finishing and polishing of fillings on the mechanical parameters, but the analysis of thermal parameters has led to uncertain results due to the difficulty of performing this in vivo. Background: We set out to conduct a study, using the finite element method, to determine the extent to which the type of class II cavity and the volume of the composite filling influence the duration of heat transfer to the pulp during finishing and polishing without cooling. Materials and Methods: A virtual model of an upper primary molar was used, with a caries process located on the distal aspect, in which four types of cavities were digitally prepared: direct access, horizontal slot, vertical slot and occlusal–proximal. All four cavity types were filled using a Filtek Supreme XT nanocomposite. Results: The study showed that the filling volume almost inversely proportionally influences the time at which the dental pulp reaches the critical temperature of irreversible damage. The lowest duration occurred in occlusal–distal restorations and the highest in direct access restorations. Conclusions: based on the results of the study, a working protocol can be issued so that finishing and polishing restorations without cooling are safe for pulpal health.

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“…Temperature effect on the structure of human tooth has been analyzed in air by different techniques since long ago. It is well known that when teeth are submitted to temperature in air, structural changes can be evidenced by color changes and fractures [7] [8], as well as changes hardness [9] and electrical conductivity [10]. For example, Reyes-Gasga et al [11] and Tiznado-Orozco et al [12] studied healthy and carious samples in the range 20˚C to 600˚C and the variations in the HAP hexagonal lattice parameters were related with ion substitution of 2 3 CO − in the OH − and 3 4 PO − sites.…”

Section: Introductionmentioning

confidence: 99%

Structural Changes in Human Teeth after Heating up to 1200&deg;C in Argon Atmosphere

Vargas-Becerril¹,

Garcı́a-Garcı́a²,

Reyes‐Gasga³

2018

MSA

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The phase transformation of hydroxyapatite (HAP, Ca 10 (PO 4) 6 (OH) 2) to the beta tricalcium phosphate phase (β-TCP, β-Ca 3 (PO 4) 2) at 1100˚C is well known. However, in the case of human tooth, the HAP phase transformation is still an open area. For example, the CaO phase has sometimes been reported in the set of phases that make up the teeth. In this study, physical changes of human teeth when subjected to heat treatment in inert atmosphere (argon) were studied. The results were compared with those obtained in air atmosphere, from room temperature (25˚C) up to 1200˚C. Morphological changes were analyzed by light and scanning electron microscopy (SEM). The HAP to β-TCP phase transformation was followed in powder samples by X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR). Heating of teeth results in the removal of organic material and structural water before the HAP to β-TCP phase transformation, the increment in hardness and the induced crystal growth. The percentage of the phases, crystal growth and lattice parameter variations as a function of temperature was quantified by Rietveld analysis. The black color was observed in dentin heated under argon atmosphere. Differences in expansivity produce fractures in dentin at 300˚C in argon and at 400˚C in air. In dentin, the coexistence of the HAP and β-TCP phases was observed after 800˚C in argon and after 600˚C in air; in enamel it was observed at 600˚C in argon compared with 400˚C in air. In general, the role played by the argon atmosphere during the thermal treatment of the teeth is to retard the processes observed in air.

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Structural and Dielectrical Properties of Sterilized Human Teeth

Cited by 4 publications

References 11 publications

The SEM electron‐mirror effect in human tooth and synthetic hydroxyapatite samples

The SEM electron‐mirror effect in human tooth and synthetic hydroxyapatite samples

A Finite Element Method Study on a Simulation of the Thermal Behaviour of Four Methods for the Restoration of Class II Cavities

Structural Changes in Human Teeth after Heating up to 1200&deg;C in Argon Atmosphere

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Structural and Dielectrical Properties of Sterilized Human Teeth

Cited by 4 publications

References 11 publications

The SEM electron‐mirror effect in human tooth and synthetic hydroxyapatite samples

The SEM electron‐mirror effect in human tooth and synthetic hydroxyapatite samples

A Finite Element Method Study on a Simulation of the Thermal Behaviour of Four Methods for the Restoration of Class II Cavities

Structural Changes in Human Teeth after Heating up to 1200&amp;deg;C in Argon Atmosphere

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Structural Changes in Human Teeth after Heating up to 1200°C in Argon Atmosphere