A microradiographic comparison of sound and carious human dental cementum

doi:10.1016/0003-9969(68)90075-7

Archives of Oral Biology

Volume 13, Issue 10, October 1968, Pages 1197-1204, IN11-IN12, 1205-1206, IN13

https://doi.org/10.1016/0003-9969(68)90075-7 Get rights and content

Abstract

The mineral distribution in sound and carious human acellular and cellular cementum was studied by microradiography of thin sections. Observations on the sound tissue confirmed the occurrence of alternating bands of high and low mineral content and also the formation of a densely mineralized layer at the external surface of cementum exposed to the oral environment. Carious cementum showed subsurface demineralization and the frequent occurrence of a densely mineralized surface layer wider than that observed in exposed, non-carious cementum. A densely mineralized layer was frequently observed at the cemento-dentinal junction. In the central portion of the tissue two patterns of mineral distribution were noted. One of the patterns was characterized by a uniform demineralization, while the other showed radially oriented areas of marked demineralization alternating with areas of high mineral content, giving the tissue a brush-like appearance. The various changes observed were interpreted as having resulted from the processes of demineralization and remineralization.

Résumé

La distribution inorganique du cément humain normal et carié, cellulaire et acellulaire, est étudieé par microradiographie de coupes fines. L'examen du tíssu sain confirme la présence de bandes alternantes à contenu minéral élevé et faible ainsi que la présence d'une couche fortement minéralisée à la surface externe du cément, exposé au milieu buccal. Le cément carié montre une déminéralisation de sub-surface ainsi qu'une couche externe, à minéralisation élevée, plus large que celle observée dans le cément à nu et non carié. Une couche à minéralisation dense est souvent observée le long de la jonction cément-dentine. Au centre du tissu, 2 types de distribution minérale sont notés. L'un des types est caractérisé pour une déminéralisation uniforme alors que le second se présente sous la forme de régions de minéralisation élevée et de déminéralisation, disposées en rayons alternés, avec aspect en brosse. L'ensemble de ces aspects semble liéà des phénomènes de déminéralisation et reminéralisation.

Zusammenfassung

Mit Hilfe der Dünnschnitt-Mikroradiographie wurde die Mineral-verteilung im gesunden und kariösen, zellosen und zellhaltigen menschlichen Zement untersucht. Die Beobachtungen an gesundem Gewebe bestätigten das Vorkommen alternierender Streifen mit hohem und niedrigem Mineralgehalt wie auch die Bildung einer dicht mineralisierten Schicht an der äuβeren, der Mundhöhle ausgesetzten Oberfläche des Zements. Kariöser Zement zeigte Demineralisation unter der Oberfläche und häufig eine im Vergleich zum freiliegenden, nichtkariösen Zement breitere Schicht dichter Mineralisation an der Oberfläche. Häufig wurde auch an der Zement-Dentingrenze eine dichte mineralisierte Schicht beobachtet. Im Zentrum des Gewebes wurden zwei Arten der Mineralverteilung beobachtet: Die eine war durch uniforme Demineralisation charakterisiert, während der andere Typ radiär orientierte Bezirke deutlicher Demineralisation im Wechsel mit Bezirken hohen Mineralgehaltes zeigte, so daβ das Gewebe ein bürstenähnliches Aussehen erhielt. Die verschiedenen Erscheinungen wurden als Ergebnis von Demineralisations- und Remineralisationsprozessen gedeutet.

References (27)

A. Forsberg et al.
Dental calculus
Oral Surg.
(1960)
C. Guzman et al.
A soft roentgen-ray study of early carious lesions
J. Am. dent. Ass.
(1957)
E. Johansen
The nature of the carious lesion
Dent. Clin. N. Am.
(1962)
I.A. Mjör
Histologic studies of human coronal dentine following cavity preparations and exposure of ground facets in vivo
Archs oral Biol.
(1967)
R. Amprino et al.
Historadiographic and autoradiographic researches on hard dental tissues
Acta anat.
(1956)
M. Araiche et al.
Soft X-ray studies of carious dentin
Y. Awazawa
Electron microscopy of carious cementum. With special reference to early caries
J. Nihon Univ. Sch. Dent.
(1961)
G. Bergman et al.
Studies on mineralized dental tissues. V. Microradiographic investigation of experimentally produced caries and attrition in white rats
Acta odont. scand.
(1954)
G. Bergman et al.
A quantitative microradiographic study of incipient enamel caries
J. dent. Res.
(1966)
F. Brudevold et al.
Physico-chemical aspects of the enamel-saliva system
Adv. Fluor. Res.
(1965)

F. Dreyfuss et al.

Microradiographie et microscopie électronique du cément humain

Bull. Grpmt int. Rech. scient. Stomat.

(1964)

F.R. von der Fehr

A study of carious lesions produced in vivo in unabraded, abraded, exposed, and F-treated human enamel surfaces, with emphasis on the X-ray dense outer layer

Archs oral Biol.

(1967)

R. Furseth et al.

Microradiographic and electron microscopic studies on carious lesions of human dental cementum

Cited by (45)

Incremental lines in human cellular cementum: A histological study
2023, Journal of Oral Biosciences
Citation Excerpt :
Some lamellae contain no or only a few Sharpey's fibers, and such cementum lamellae do not work as a tooth-fixing device but instead work to adjust and disperse the masticatory force in cooperation with other periodontal tissues [1]. Many investigators have studied incremental lines under light microscopy, scanning electron microscopy, and contact microradiography [2–9]. As a result, it is widely believed that the incremental lines, like the resting lines in bone, are highly mineralized and are generated between the resting and formative phases of cellular cementogenesis [4–9].
Human cellular cementum has incremental lines that demarcate individual cementum lamellae. The structural and functional details of the lines remain poorly understood. This study was designed to examine human cellular cementum using light microscopy, scanning electron microscopy, and contact microradiography and to elucidate the ultrastructure of incremental lines and their significance in cellular cementogenesis.
Longitudinal paraffin and ground sections of human mandibular molars were prepared. Paraffin sections were stained with hematoxylin, or hematoxylin and eosin, or impregnated with silver. Hematoxylin-stained sections were observed via scanning electron microscopy using NaOH maceration. Silver-impregnated sections were further stained with hematoxylin. Hematoxylin-stained ground sections were examined using contact microradiography.
The incremental lines were found to be collagen fibril-poor layers. The outer area of each cementum lamella consisted of highly mineralized fibrils involved in constructing an alternating lamellar structure, whereas the inner area consisted of irregularly arranged, less highly mineralized, fibrils. The incremental lines corresponded with the innermost sites of the inner area.
Based on the obtained findings, we suggest that cellular cementogenesis progresses as follows. (1) Cementoblasts alternate between low-to high-activity states. (2) In the earliest low-activity stage, cementoblasts generate poorly mineralized, fibril-poor, incremental lines. (3) As cementoblasts recover activity, fibril-organization and mineralization advance in the cementum. (4) In the high-activity stage, cementoblasts reach full activity and construct the highly mineralized, alternating lamellar structure. (5) Cementoblasts revert back to the low-activity stage. (6) The above processes are repeated, thus, alternately generating the incremental lines and cementum lamellae.
Effects of cementum-dentine junction and cementum on the mechanical response of tooth supporting structure
2010, Journal of Dentistry
Citation Excerpt :
It is proposed that the periodontium of a tooth contains two fibrous joints (PDL and cementum–dentine junction (CDJ)) that accommodate the masticatory cyclic loads.1 It is worth pointing out that many years ago the morphology investigation on human tooth including CDJ and cementum was reported.16,17 Some authors have made attempts to present the structure and biomechanical function of cementum and CDJ.18,19
The aim of the present work is to investigate the effects of cementum–dentine junction (CDJ) and cementum on the stress distribution in the periodontal ligament (PDL) and alveolar bone.
Based on the anatomical profiles and the recently reported theories about the tooth attachment mechanism, the finite element (FE) model of a mandibular second premolar along with its detailed supporting structures was developed. The effect of CDJ and cementum was evaluated by comparing the resulting stresses of FE models of the second mandibular premolar with and without CDJ and cementum in tooth supporting structure.
The stress levels are higher in the structure without CDJ and cementum than that with CDJ and cementum. The function of CDJ and cementum is as a cushion pad decreasing the stress in the PDL and alveolar bone under loading.
As a major result of this study, it can be concluded that the CDJ and cementum significantly influence the stress distribution within the tooth supporting structure. However, most of the reported FE analysis did not take CDJ and cementum into account, which possibly resulted in overestimated stress values in the PDL and alveolar bone. From a bio-engineering perspective, the results of this study provide guidance for the design of dental implants and the application of orthodontic force system as well.
Effects of a self-etching resin coating system to prevent demineralization of root surfaces
2008, Dental Materials
The purpose of this study was to evaluate the ability of an experimental self-etching resin coating system to protect against demineralization of the root surface in vitro, comparing its effectiveness with two commercial one-step self-etching adhesives.
The experimental resin coating system (EC), consisting of a self-etching primer and an acrylate-based resin, or the two commercial self-etching adhesives, Adper Prompt-L Pop (AD) and Clearfil Tri-S Bond (S3), was applied to the cementum of a human extracted tooth root. The specimens were immersed in acetate buffer at pH 5.5 for 4 weeks, and the degree of demineralization underneath the materials was evaluated by microscopic observation and contact microradiography. Each material's sealing and interfacial ultrastructure on the cementum was morphologically examined by scanning electron microscopy, and their bonding ability to cementum was determined by microtensile bond strength (MTBS) tests.
Application of AD and S3 showed limited effects to protect against demineralization, but no demineralization was observed for EC. EC showed greater coating thickness than the other two materials, with formation of integral hybridized layers with cementum. Although the MTBS values for EC were significantly lower than those for AD and S3, cohesive failure in resins was the prevalent fracture mode for EC, showing no possible disadvantages in bonding ability.
The experimental resin coating system effectively prevented acid demineralization on root surfaces due to its ability to produce an appropriately thick coating and an integral hybridized layer.
Comparisons between bone and cementum compositions and the possible basis for their layered appearances
2002, Bone
In humans, age estimation from the adult skeleton represents an attempt to determine chronological age based on growth and maturational events. In teeth, such events can be characterized by appositional growth layers in midroot cementum. The purpose of this study was to determine the underlying cause of the layered microstructure of human midroot cementum. Whether cementum growth layers are caused by changes in relative mineralization, collagen packing and/or orientation, or by variations in organic matrix apposition was investigated by subjecting midroot sections of human canine teeth to analysis using polarized light and scanning electron microscopy (SEM). Polarized light was used to examine transverse midroot sections in both mineralized and demineralized states. Mineralized sections were also reexamined following subsequent decollagenization. Polarized light was additionally used in the examination of mineralized sections taken transversely, longitudinally, and obliquely from the same tooth root. From the birefringence patterns it was concluded that collagen orientation does not change with varying section plane. Instead, the mineral phase was most responsible for the birefringence of the cementum. SEM studies suggested that neither collagen packing nor collagen orientation change across the width of the cementum, confirming and validating the results of the polarized light examination. Also, SEM analysis using electron backscatter and the electron probe suggested no changes in the mean atomic number density, calcium, phosphate, and sulfur levels across the width of the cementum. Therefore, we conclude that crystalline orientation and/or size is responsible for the layered appearance of cementum.
Bonding of all-porcelain crowns: Structural characteristics of the substrate
2001, Dental Materials
Objectives: The aim of this in vitro study was to evaluate the morphology of dentin in teeth prepared for single-unit all-porcelain crowns (SUAPC) in terms of tubule orientation, density and increase in surface area after etching.
Methods: Twenty anterior and 20 posterior teeth from adults were prepared 1 mm below the cemento-enamel junction (CEJ) for SUAPC. The samples were divided into groups based on type of tooth (anterior or posterior) and bonding system employed. The teeth were processed for evaluation of morphology of the substrate, hybrid layer thickness and resin tag formation. The observations were subdivided according to location in the preparation and tubule density was calculated.
Results: The observations revealed the variability in tubule density and orientation in different areas within any one preparation. The morphology of the cervical margin was less predictable with the presence of cementum and an ill-defined cemento-dentinal junction. Statistically significant differences in the density of tubules were found depending on location. Groups 2, 3, 5 and 6 samples showed that the hybrid layer thickness and resin tag morphology depended on the density and direction of tubules. In those sectors with parallel and oblique tubule orientation and with a low density of tubules, the hybrid layer was significantly thinner than in areas with cross-sectioned tubules.
Significance: The cementum and the peripheral intertubular dentin surface area are likely to be responsible for the bond strength after acid etching of crown preparations, but not all areas exhibited equal responses to etching. In particular, the bonding substrate at the gingival margins may contribute little in terms of micromechanical retention.
Intermediate cementum. Development, structure, composition, and potential functions
1995, Oral Surgery, Oral Medicine, Oral Pathology, Oral Radiology and
In the roots and root analogs of mammalian teeth a narrow zone of highly calcified tissue occupies the junctionbetween cementum and dentin. This zone is referred to as “intermediate cementum”, despite evidence that it is not a product of cementogenesis (or of dentinogenesis). Studies conducted on teeth of human and nonhuman primates indicate that the intermediate cementum layer contains enamel matrix proteins and is likely a product of Hertwig's epithelial root sheath. The available evidence regarding the development (origin), structure, and composition of intermediate cementum is reviewed, and the potential functions of this layer are assessed to include a possible role in wound healing.

View all citing articles on Scopus

^∗: Present address: Dental Institute of Experimental Research, University of Oslo, Blindern, Oslo 3, Norway.

View full text

Article preview

Archives of Oral Biology

Abstract

Résumé

Zusammenfassung

References (27)

Dental calculus

Oral Surg.

A soft roentgen-ray study of early carious lesions

J. Am. dent. Ass.

The nature of the carious lesion

Dent. Clin. N. Am.

Histologic studies of human coronal dentine following cavity preparations and exposure of ground facets in vivo

Archs oral Biol.

Historadiographic and autoradiographic researches on hard dental tissues

Acta anat.

Soft X-ray studies of carious dentin

Electron microscopy of carious cementum. With special reference to early caries

J. Nihon Univ. Sch. Dent.

Studies on mineralized dental tissues. V. Microradiographic investigation of experimentally produced caries and attrition in white rats

Acta odont. scand.

A quantitative microradiographic study of incipient enamel caries

J. dent. Res.

Physico-chemical aspects of the enamel-saliva system

Adv. Fluor. Res.

Microradiographie et microscopie électronique du cément humain

Bull. Grpmt int. Rech. scient. Stomat.

A study of carious lesions produced in vivo in unabraded, abraded, exposed, and F-treated human enamel surfaces, with emphasis on the X-ray dense outer layer

Archs oral Biol.

Microradiographic and electron microscopic studies on carious lesions of human dental cementum

Cited by (45)

Incremental lines in human cellular cementum: A histological study

Effects of cementum-dentine junction and cementum on the mechanical response of tooth supporting structure

Effects of a self-etching resin coating system to prevent demineralization of root surfaces

Comparisons between bone and cementum compositions and the possible basis for their layered appearances

Bonding of all-porcelain crowns: Structural characteristics of the substrate

Intermediate cementum. Development, structure, composition, and potential functions