Computer-assisted Reconstruction of Enamel Fissures and Carious Lesions of Human Premolars

Abstract

The origin of cariogenesis in occlusal fissures remains elusive because of limited information about both the fissure structure and the morphologic details of carious lesions occurring there. The present study was aimed at reconstructing the coronal structure of human premolars with the aid of computer-assisted image analysis and, on the basis of the reconstructed structures, investigating the configuration of fissures, their proximity to the enameldentin junction (EDJ), and the occurrence and extension of carious lesions around the fissure walls. The coronal portions of the teeth were embedded in polyester resin and then ground off stepwise by hand. Serial images of the enamel contour on successive ground planes were recorded by objective microscopy after it was distinctly demarcated with either 0.5 w/v% carbol fuchsin or 1 w/v% basic fuchsin. Usually, from 150 to 250 photoprints were collected from a single enamel crown to reproduce the details of the fissure structures. The enamel outline (the occlusal and lateral surfaces, fissure walls, and EDJ) and, if present, the outline of caries-attacked areas were traced accurately on those photoprints by means of a digitizing system. The enamel contour data in series were input into an image analyzing system (Nikon COSMOZONE, 2SA). Observation of the computer-drawn coronal enamel allowed us to view the morphologic features of the fissures (shape, divarication, and proximity to EDJ) and to scrutinize the pathway of enamel caries along fissure walls. The results indicate that the computer-assisted reconstruction of enamel crown, in conjunction with the step-by-step grinding technique, is useful in basic and clinical studies of occlusal fissure caries.

Keywords

enamel occlusal fissures caries ,3D morphology

Get full access to this article

View all access options for this article.

References

Atsuta T. , Suga S. ( 1992). Microradiographic investigations of the process of carious invasion in the enamel surrounding occlusal fissures-A comparison between the lesions of young and old people Odontology 96:1465-1493.

Chu LSS , Suga S. ( 1991). Microradiographic study on the chronic carious lesion in the occlusal enamel. Odontology 79:515-547.

Dykes E. , Piper K. , Coodson MJ , Holman JG (1989), Enamel thickness, surface area and volume determined by a computer based 3D recording technique. In: Tooth Enamel

V. Proceedings of the Enamel Symposium V, August 21-25, 1989, Tsurumi, Japan . Fearnhead RW , editor. Tokyo: Bunkashoin Co., pp.417-421.

Fejerskov O. , Melsen B. , Karring T. (1973). Morphometric analysis of occlusal fissures in human premolars. Scand J Dent Res 81:505-510.

Fukuda H. , Suga S. ( 1986). Histological studies on the early carious lesions in fissures. Odontology 73:1780-1814.

Galil KA , Gwinnett AJ (1975). Three-dimensional replicas of pits and fissures in human teeth: Scanning electron microscopy study. Arch Oral Biol 20:493-495.

Juhl M. ( 1983). Three-dimensional replicas of pit and fissure morphology in human teeth. Scand Dent Res 91:90-95.

Kimura O. , Dykes E. , Fearnhead RW (1977). The relationship between the surface area of the enamel crowns of human teeth and that of the dentine-enamel junction. Arch Oral Biol 122:667-683.

10.

Konig KG (1963). Dental morphology in relation to caries resistance with special reference to fissues as susceptible areas. J Dent Res 42:461-476.

11.

Konig KG (1965). Findings in serially sectioned teeth showing early fissure lesions. Adv Fluor Res Dent Caries Prev 4:73-79.

12.

Lussi A. (1991). Validity of diagnostic and treatment decisions of fissure caries. Caries Res 25:296-303.

13.

Nagano T. (1960). Relation between the form of pit and fissure and the primary lesion of caries. Shika Gakuho 60:80-90.

14.

Newbrun E. (1989). Cariology. 3rd ed. Chicago: Quintessence Publishing Co. , pp. 248-250.