Sound crown. A crown is coded as sound if it shows no evidence of treated or untreated clinical caries (see Plate 1, code A, and Plate 6, code 0). The stages of caries that precede cavitation, as well as other conditions similar to the early stages of caries, are excluded because they cannot be reliably identified in most field conditions in which epidemiological surveys are conducted. Thus, a crown with the follow- ing defects, in the absence of other positive criteria, should be coded as sound (see Plates 7 and 8): • white or chalky spots; discoloured or rough spots that are not soft • to touch with a metal CPI probe; stained enamel pits or fissures that do not have visible cavitation or • softening of the floor or walls detectable with a CPI probe; dark, shiny, hard, pitted areas of enamel in a tooth showing signs of • moderate to severe enamel fluorosis; lesions that, on the basis of their distribution or history, or on exami- nation, appear to be due to abrasion. Sound root. A root is recorded as sound when it is exposed and shows no evidence of treated or untreated clinical caries (see Plate 9).

0 (A)

Carious crown. Caries is recorded as present when a lesion in a pit or fissure, or on a smooth tooth surface, has an unmistakable cavity, undermined enamel, or a detectably softened floor or wall (see Plates 2–4 Primary dentition, and Plates 10–12 Permanent dentition). A tooth with a temporary filling, or one which is sealed but also decayed, should also be included in this category. In cases where the crown has been destroyed by caries and only the root is left, the caries is judged to have originated in the crown and is therefore scored as crown caries only. The CPI probe should be used to confirm visual evidence of caries on the tooth surface(s). Where any doubt exists, caries should not be recorded as present. Carious root. Caries is recorded as present when a lesion feels soft or leathery on probing with the CPI probe. If the carious lesion on the root does not involve the crown, it should be recorded as root caries. For single carious lesions affecting both the crown and the root, the likely site of origin of the lesion should be recorded as the decayed site. When it is not possible to identify the site of origin, both the crown and the root should be coded as decayed. In general, root caries is not recorded for children and in youth or young adults.

1 (B)

Filled crown, with caries. A crown is considered filled, with decay, when it has one or more permanent restorations and one or more areas that are decayed. No distinction is made between primary and secondary caries and the same code applies regardless of whether the carious lesions are in contact with the restoration(s) (see Plates 13 and 14). Filled root, with caries. A root is considered filled, with caries, when it has one or more permanent restorations and one or more areas that are decayed. No distinction is made between primary and secondary caries. In the case of restorations involving both the crown and the root, identification of the site of origin is more difficult. For any restoration involving both the crown and the root with secondary caries, the most likely site of the primary carious lesion is recorded as filled, with decay. When it is not possible to identify the site of origin of the primary carious lesion, both the crown and the root should be coded as filled, with caries.

2 (C)

Filled crown, with no caries. A crown is considered filled, without caries, when one or more permanent restorations are present and there is no caries anywhere on the crown (see Plates 5 and 15). A tooth that has been crowned because of previous decay is recorded in this category. A tooth that has been crowned for reasons other than caries by means of a fixed dental prosthesis abutment is coded 7 (G). Filled root, with no caries. A root is considered filled, without caries, when one or more permanent restorations are present and there is no caries anywhere on the root. In the case of fillings involving both the crown and the root, identification of the site of origin is more difficult. For any restoration involving both the crown and the root, the most likely site of the primary carious lesion is recorded as filled. When it is not possible to identify the site of origin, both the crown and the root should be coded as filled.

3 (D)

Missing tooth, due to caries. This code is used for permanent or primary teeth that have been extracted because of caries and are recorded under coronal status (see Plates 16 and 17). For missing primary teeth, this score should be used only if the subject is at an age when normal exfoliation would not be a sufficient explanation for absence. Note: The root status of a tooth that has been scored as missing because of caries should be coded “7” or “9”. In some age groups, it may be difficult to distinguish between unerupted teeth (code 8) and missing teeth (codes 4 or 5). Basic knowledge of tooth eruption patterns, the appearance of the alveolar ridge in the area of the tooth space in question, and the caries status of other teeth in the mouth may provide helpful clues in making in deciding whether a tooth is unerupted or has been extracted. Code 4 should not be used for teeth deemed to be missing for any reason other than caries. For convenience, in fully edentulous arches, a single “4” should be placed in Boxes 45 and 60; and 77–92, as appropriate, and the respective pairs of numbers linked with straight lines. Such procedure may also be applied where the record form for registration at tooth surface level is used (Annex 3 and Annex 4).

4 (E)

Permanent tooth missing due to any other reason. This code is used for permanent teeth deemed to be absent congenitally, or extracted for orthodontic reasons or because of periodontal disease, trauma, etc. (see Plate 18). As for code 4, two entries of code 5 can be linked by a line in cases of fully edentulous arches. Note: The root status of a tooth scored 5 should be coded “7” or “9”.

5 (-)

Fissure sealant. This code is used for teeth in which a fissure sealant has been placed on the occlusal surface, in pits or for teeth in which the occlusal fissure has been enlarged with a rounded or “flame-shaped” bur, and a composite material placed (see Plate 19). If a tooth with a sealant has caries, it should be coded as 1 or B.

6 (F)

Fixed dental prosthesis abutment, special crown or veneer. This code is used under coronal status to indicate that a tooth forms part of a fixed bridge abutment. This code can also be used for crowns placed for reasons other than caries and for veneers or laminates covering the labial surface of a tooth, on which there is no evidence of caries or a restora- tion (see Plate 20). Note: Missing teeth replaced by fixed partial denture pontics are coded 4 or 5 under coronal status, while root status is scored 9. Implant. This code is used under root status to indicate that an implant has been placed as an abutment.

7 (G)

Unerupted tooth (crown). This classification is restricted to permanent teeth and used only for a tooth space with an unerupted permanent tooth but no primary tooth. Teeth scored as unerupted are excluded from all calculations concerning dental caries (see Plate 1 (incisors) and Plate 21). This category does not include congenitally missing teeth, or teeth lost as a result of trauma etc. For differential diagnosis between missing and unerupted teeth, see code 5. Unexposed root. This code indicates that the root surface is not exposed; there is no gingival recession beyond the cement-enamel junction (CEJ).

8 (-)

Not recorded. This code is used for an erupted permanent tooth that cannot be examined for any reason such as orthodontic bands, severe hypoplasia, etc. This code is used under root status to indicate either that the tooth has been extracted or that calculus is present to such an extent that root examina- tion is not possible.

9 (-)