Nanoindentation mapping of the mechanical properties of human molar tooth enamel

Cuy, J.L.; Mann, A.; Livi, Kenneth J. T.; Teaford, Mark F.; Weihs, Timothy P.

doi:10.1016/s0003-9969(02)00006-7

Cited by 606 publications

(488 citation statements)

References 29 publications

Supporting

Mentioning

416

Contrasting

Unclassified

Order By: Relevance

“…Investigators have typically presented the mechanical properties of enamel with average values measured away from the occlusal surface (Table 1). Using nanoindentation methods Cuy et al 10 showed that the highest values of E and H (and the most rapid decrease in E and H) are found near the cusp tips. E and H are significantly lower in the majority of the enamel, hundreds of microns below the occlusal surface as noted by Cuy et al 10 Since most earlier reports focus primarily in this middle region, between the occlusal surface and the DEJ, lower values have been reported as seen in Table 1.…”

Section: Discussionmentioning

confidence: 99%

“…These differences in mechanical properties were attributed to higher organic tissue in the inter-rod areas. Cuy et al 10 showed a strong correlation between decreases in Young's modulus and hardness values and drops in mineral content, CaO and P 2 O 5 , specifically.…”

Section: Introductionmentioning

confidence: 97%

“…Many researchers have characterized the chemistry of human enamel as a function of position, 11,12,13,14,15,16 and in some cases the results have been correlated with spatial variations in the mechanical properties of enamel. 10,15,17,18,19 Habelitz et al 20 showed Young's moduli and hardness were lower in the inter-rod enamel than in the head of the enamel rod. These differences in mechanical properties were attributed to higher organic tissue in the inter-rod areas.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

The effect of prism orientation on the indentation testing of human molar enamel

Braly

Darnell

Mann

et al. 2007

Archives of Oral Biology

Self Cite

111

View full text Add to dashboard Cite

Recent nanoindentation studies have demonstrated that the hardness and Young's modulus of human molar enamel decreases by more than 50% on moving from the occlusal surface to the dentin-enamel junction on cross-sectional samples. Possible sources of these variations are changes in local chemistry, microstructure, and prism orientation. This study investigates the latter source by performing nanoindentation tests at two different orientations relative to the hydroxyapatite prisms: parallel and perpendicular. A single sample volume was tested in order to maintain a constant chemistry and microstructure. The resulting data show very small differences between the two orientations for both hardness and Young's modulus. The 1.5 to 3.0% difference is significantly less than the standard deviations found within the data set. Thus, the variations in hardness and Young's modulus on cross-sectional samples of human molar are attributed to changes in local chemistry (varying levels of mineralization, organic matter, and water content) and changes in microstructure (varying volume fractions of inorganic crystals and organic matrix). The impact of prism orientation on mechanical properties measured by nanoindentation appears to be minimal.

show abstract

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 97%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

The effect of prism orientation on the indentation testing of human molar enamel

Braly

Darnell

Mann

et al. 2007

Archives of Oral Biology

Self Cite

111

View full text Add to dashboard Cite

show abstract

“…The enamel tooth surface is very hard, typically around 3-6 GPa [17], whilst dentine is much softer (typically around 0.5 GPa [18]). The experiments performed here are carried out scratching PMMA, which has similar properties to dentine.…”

Section: Discussionmentioning

confidence: 99%

Interaction between toothbrushes and toothpaste abrasive particles in simulated tooth cleaning

Lewis

Dwyer-Joyce

Pickles

2004

Wear

View full text Add to dashboard Cite

Most people clean their teeth using toothpaste, consisting of abrasive particles in a carrier fluid, and a filament based toothbrush to remove plaque and stain. In order to optimise cleaning efficiency it is important to understand how toothbrush filaments, abrasive particles and fluid interact in a tooth cleaning contact.Work has been carried out to visualise, simulate, and model the processes in teeth cleaning.Laboratory cleaning contacts were created between a toothbrush and a transparent surface.Video and short duration flash photography were used to study the processes by which a toothbrush traps abrasive particles, loads them against the counterface, and removes material.Small abrasive particles tend to be trapped at the contact between the filament tip and the counterface, whilst larger particles are trapped by clumps of filaments or at the contact with the side of a bent filament.Measurements of brush friction force were recorded during cleaning for a range of operating conditions. The presence of abrasive particles in the cleaning mixture increased the coefficient of friction, but the absolute particle concentration showed a lesser effect. It is surmised that only a few particles carry any load and cause any abrasion; increasing the particle concentration does not directly increase the number of load bearing particles.Abrasive scratch tests were also carried out, using PMMA as a wearing substrate. The scratches produced during these tests were studied. The microscopy images were used to deduce how the filaments deflect and drag, and how particles are trapped by filaments and scratch the surface. Again, it was observed that few of the brush filaments loaded particles to produce scratches, and that when a filament changes direction of travel the trapped particle is lost.Results of these studies were used to develop both qualitative and quantitative models of the process by which material is removed in teeth cleaning. The quantitative model contains, by necessity, several empirical factors, but nonetheless predictions compare well with in vitro wear results from the literature. The results were also used to draw some broad conclusions on appropriate brushing techniques for optimum tooth cleaning.

show abstract

“…Though bite forces can allow materials of lesser hardness to indent a harder solid, this is far less likely a cause than indentation by materials of greater or equal material hardness. The hardness of squamate enamel is not yet known, but the likely value of its hardness is somewhere between that of pure apatite (Dietrich, 1969) and mammalian enamel (Cuy et al, 2002;Xu et al, 1998) , and may be similar to that of estimates made for the enamel of some archosaurs (Erickson et al, 2012). Mosasaur enamel is known to have a structure that may allow some specialisations to avoid fracture such as modifications to its thickness (Sander, 1999), but it is not prismatic like mammalian enamel and may not be as resistant to indentation and more prone to fracture.…”

Section: Abrasivesmentioning

confidence: 99%

Dental macro- and microwear in Carinodens belgicus, a small mosasaur from the type Maastrichtian

Holwerda

Beatty

Schulp

2013

Netherlands Journal of Geosciences

View full text Add to dashboard Cite

Teeth of the small durophagous mosasaur Carinodens belgicus are known from Maastrichtian Atlantic-Tethyan deposits worldwide. The peculiar dentition of Carinodens inspired debate and speculation on its dietary niche ever since its first description. In this contribution, we describe the macro- and microwear pattern in five well-preserved isolated teeth, allowing further and independent evaluation of aspects of feeding behaviour and diet. Macroscopically, wear is concentrated on the apex and mesiodistal sides. Microwear was mapped using Scanning Electron Microscopy at several magnifications and can be characterised as scratches and pits. Coarse scratches were found to be the most common and pits were found to be the least common feature. Scratch orientation is primarily along the mesiodistal plane or in the labiolingual plane with an angle of ~130°. These microwear features can be explained either by oral processing or passive abrasion by sediments or food. As scratch width only indicates the minimum width of the abrading particle, the material causing the wear here could have ranged from silica-based silts to larger abrasives. However, in this case, abrasion by sediments might not explain this wear because of the biocalcarenitic nature of the type Maastrichtian sediments; siliciclastics are virtually absent. Therefore it is more likely that hard food particles, such as benthic organisms with hard exoskeletons, caused the wear on the enamel of Carinodens, or Carinodens ventured out to more sandy areas to forage as well. The mesiodistal and labiolingual direction of the microwear scratches might suggest that Carinodens showed more complexity in the use of its teeth than simple grasping, and that a gripping and pulling motion during feeding similar to that employed by modern varanids may have been the cause.

show abstract

Nanoindentation mapping of the mechanical properties of human molar tooth enamel

Cited by 606 publications

References 29 publications

The effect of prism orientation on the indentation testing of human molar enamel

The effect of prism orientation on the indentation testing of human molar enamel

Interaction between toothbrushes and toothpaste abrasive particles in simulated tooth cleaning

Dental macro- and microwear in Carinodens belgicus, a small mosasaur from the type Maastrichtian

Contact Info

Product

Resources

About