Possible Physico-Chemical Processes in Human Dentin Caries

Daculsi, Guy; LeGeros, Racquel Z.; Jean, A.; Kerébel, B

doi:10.1177/00220345870660081401

Cited by 94 publications

(85 citation statements)

References 13 publications

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“…Lower magnesium (Mg) amount present in sclerotic dentin is in agreement with literature data [40]. Mg is a natural constituent of hydroxyapatite present in peritubular and intertubular dentin.…”

Section: Discussionsupporting

confidence: 90%

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Determination of chemical elements and cross-section hardness of sclerotic darkened human dentin

Souza

Meirelles

Duque

et al. 2017

BDS

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Objective: The aim of this study was to assess the amount of chemical elements (Ca, O, C, P, Fe, and Mg) and the cross-section hardness of sclerotic darkened dentin in human teeth. Material and Methods: The study was approved by the local IRB and ten extracted teeth (five sound and five presenting sclerotic darkened dentin) were used. Tooth was sectioned mesiodistally and each half was used for each test. Amount of chemical elements (%w) was determined by energy dispersive X-ray spectroscopy (EDS) in three different dentin areas (shallow, medium, or deep sound or sclerotic dentin). Knoop microhardness was determined at the same EDS areas. Data were analyzed by two-way ANOVA and multiple comparison tests, with significance level at 5%. Results: No difference on microhardness was detected between sound and sclerotic dentin (p = 0.743) and also among dentin depths (p = 0.837). Lower Ca (p = 0.024) and higher C (p = 0.015) amounts were found at superficial sclerotic dentin. Increased Mg content (p < 0.001) was detected in sound dentin. Conclusion: It was concluded darkened sclerotic dentin presents similar cross-section microhardness to sound dentin. The assessed chemical elements were similarly present in sound or sclerotic dentin, except for Mg, which was present higher concentration in sound dentin. Ca and P were lower in superficial sclerotic dentin. ReSumoObjetivo: O objetivo deste estudo foi avaliar a quantidade de elementos químicos (Ca, O, C, P, Fe e Mg) e a microdureza superficial da dentina esclerótica escurecida em dentes humanos. Material e Métodos: O estudo foi aprovado pelo Comitê de Ética local e dez dentes extraídos (cinco hígidos e cinco apresentando dentina esclerosada) foram utilizados. Os dentes foram seccionados no sentido mésiodistal e cada metade foi utilizada para cada teste. A quantidade de elementos químicos (%w) foi determinada pela espectroscopia de raio-x por dispersão em energia (EDS) em três áreas dentinárias diferentes (superficial, média ou profunda). Estas mesmas áreas tiveram a microdureza superficial Knoop determinada. Os dados foram analisados por ANOVA dois fatores e teste de comparações múltiplas, com nível de significância de 5%. Resultados: Nenhuma diferença quanto à microdureza foi detectada entre a dentina hígida e esclerótica (p = 0,743) e nem em relação às profundidades (p = 0,837). Menor quantidade de Ca (p = 0,024) e maior quantidade de C (p = 0,015) foram encontradas na dentina esclerótica superficial. O aumento do conteúdo de Mg (p < 0,001) foi detectado na dentina hígida. Conclusão: Pode-se concluir que a dentina esclerótica apresenta microdureza superficial similar à dentina hígida. Os elementos químicos estudados apresentaram-se igualmente para os dois tipos de dentina, exceto para o Mg, o qual estava em maior quantidade na dentina hígida. O cálcio e o fósforo apresentaram quantidades reduzidas na dentina esclerótica superficial.

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Section: Discussionsupporting

confidence: 90%

“…Mg is a natural constituent of hydroxyapatite present in peritubular and intertubular dentin. Magnesium is the first element to be lost during dentin demineralization process, even prior to Ca and P [40]. Remineralization presents restored mineral content (non-apatite) often with no Mg on its composition.…”

Section: Discussionmentioning

confidence: 99%

Determination of chemical elements and cross-section hardness of sclerotic darkened human dentin

Souza

Meirelles

Duque

et al. 2017

BDS

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“…Rhombohedral crystals were often observed (1) in den tinal tubules that underlie both active and arrested lesions Daculsi et al, 1979;Frank and Voegel, 1980;Daculsi et al, 1987], (2) in dentinal tubules under neath surface areas that show evidence of occlusal attri tion [Mendis and Darling, 1979] and (3) in dentinal tubules of specimens obtained from naturally desensitized areas of hypersensitive teeth [Yoshiyama et al, 1989[Yoshiyama et al, ,1990. They were identified as whitlockite crystals (Mg-substituted (i-tricalcium phosphate, P-TCMP) Vahl et al, 1964;Takuma et al, 1969;Daculsi et al, 1979Daculsi et al, , 1987Frank and Voegel, 1980], Daculsi et al [1987] suggested that the formation of crystals of [1-TCMP in arrested den tin caries occurs stepwise by the dissolution of intertubular dentin, the saturation of the solution in the dentinal tu bules with calcium, phosphate and magnesium ions, and final rcprccipitation of [1-TCMP crystals in the tubules as suggested by Daculsi et al [1987], The coexistence of large crystals of Mg-substituted |)-TCMP and small needle-like crystals, most probably representing apatite ( fig.…”

Section: Discussionmentioning

confidence: 99%

“…They were identified as whitlockite crystals (Mg-substituted (i-tricalcium phosphate, P-TCMP) Vahl et al, 1964;Takuma et al, 1969;Daculsi et al, 1979Daculsi et al, , 1987Frank and Voegel, 1980], Daculsi et al [1987] suggested that the formation of crystals of [1-TCMP in arrested den tin caries occurs stepwise by the dissolution of intertubular dentin, the saturation of the solution in the dentinal tu bules with calcium, phosphate and magnesium ions, and final rcprccipitation of [1-TCMP crystals in the tubules as suggested by Daculsi et al [1987], The coexistence of large crystals of Mg-substituted |)-TCMP and small needle-like crystals, most probably representing apatite ( fig. 14), may be the result of a depiction of Mg2+ ions from the fluid phase during the formation of (f-TCMP and the subse quent formation of Mg-poor apatite.…”

Section: Discussionmentioning

confidence: 99%

Human Root Caries: Histopathology of Arrested Lesions

Schüpbach¹,

Lutz

Guggenheim³

1992

Caries Res

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The histopathology of arrested root caries lesions was examined in extracted human teeth. The main structural characteristics of arrested lesions were the completely mineralized surface area and the formation of a distinct sclerosis of the dentinal tubules. Intertubular dentin was, with the exception of the dentinal tubules, fully mineralized up to the surface. Dentinal tubules near the surface were either filled with ghosts of microorganisms or with crystals of different shapes. Sclerosis of the dentinal tubules was characterized by the presence of three different patterns of intratubular mineralization that occur in distinct regions of the zone of tubular sclerosis. The patterns were distinguishable by the type of crystals and their association with organic structures such as collagenous fibrils or odontoblast processes. It is suggested that arrested lesions are based on (1) the formation of an inner barrier that interrupts the diffusion of substrata from the pulp to invaded bacteria, (2) the formation of an outer barrier by a compact, highly mineralized surface region which blocks the diffusion of products of bacterial metabolism into dentin, and (3) an area of mineralization which extends from the outer barrier toward the root canal within demineralized dentin. The present study demonstrates the considerable potential of caries lesions in dentin to become arrested, and subsequently partially remineralized. These phenomena seem to depend on the severity of an active lesion and its location on the root surface. This should be taken into account when diagnosing root caries lesions. The potential of root caries lesions to become arrested indicates that the treatment concept of active root caries lesions should be reconsidered.

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“…Fine-grained deposits observed in natural lesions have been identified as apatitic, while coarse gran ules similar to those seen in several specimens in the pre sent study have been identified as WH [e.g.. Frank and Voegel. 1980;Daculsi et al, 1987;Schtipbach et ah. 1992].…”

Section: Shellismentioning

confidence: 99%

Effects of a Supersaturated Pulpal Fluid on the Formation of Caries-Like Lesions on the Roots of Human Teeth

Shellis¹

1994

Caries Res

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Root surfaces were exposed to demineralizing buffer in a continuous-flow system, with or without simultaneous perfusion of the pulp chamber with a supersaturated surrogate dentine fluid (SDF). Experimental lesions formed with perfusion of the pulp were significantly less deep than control lesions formed without perfusion, but the application of hydrostatic pressure to the SDF (15 or 30 cm water) did not produce significantly greater reductions. The lesion depth reduction was attributed to reduced undersaturation at the advancing lesion front through interdiffusion of the demineralizing buffer and the SDF. Translucent bands, resembling sclerotic dentine, were observed beneath 9 of 24 experimental lesions and 5 of 24 control lesions. Scanning electron microscopy showed that, in most of the bands beneath experimental lesions, dentinal tubules were either partly occluded by granular mineral deposits or were reduced in diameter. Thus, in vivo, dentine fluid may modify the rate of lesion progression and promote sclerosis in the underlying dentine.

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Possible Physico-Chemical Processes in Human Dentin Caries

Cited by 94 publications

References 13 publications

Determination of chemical elements and cross-section hardness of sclerotic darkened human dentin

Determination of chemical elements and cross-section hardness of sclerotic darkened human dentin

Human Root Caries: Histopathology of Arrested Lesions

Effects of a Supersaturated Pulpal Fluid on the Formation of Caries-Like Lesions on the Roots of Human Teeth

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