Analysis of cement-enamel junction using the replica technique and scanning electron microscopy.
Name: Bruna Pereira Silva Escórcio
Type: MSc dissertation
Publication date: 31/08/2012
Advisor:
Name |
Role |
|---|---|
| Rogério Albuquerque Azeredo | Advisor * |
Examining board:
| Name |
Role |
|---|---|
| Karla Loureiro Almeida Coburn | Internal Examiner * |
| Miguel Carlos Madeira | External Examiner * |
| Rogério Albuquerque Azeredo | Advisor * |
Summary: The cemento-enamel junction (CEJ) is the anatomical juncture between the enamel and cementum that covers the tooth crown and root, respectively. When changes expose the CEJ to the oral environment, the hard dental tissues of this region are vulnerable to pathological changes such as root caries, resorption, cervical erosion, abrasion and dentine hypersensitivity. The CEJ region was evaluated using the replica technique for SEM, in order to observe the different interrelationships among its mineralized tissues; if there is dentin permeability (gaps and defects with exposed dentinal tubules and lateral
canals close to this region); to analyze the regions of CEJ with non-carious cervical lesions (NCCLs) and make a correlation between the clinical and ultrastructural findings in teeth with endodontic, periodontal and endo-periodontal infections. It was used 69 faces, 44 teeth extracted from 23 patients who were underwent clinical and radiographic examination, prior to extraction, aiming to obtain pulpal, periodontal and endoperiodontal
clinical diagnosis. The teeth were cleaned and prepared, to make replicas
made with the polyvinilsiloxane impression material and epoxy resin. The positive replicas were mounted on metal stubs, sputter-coated and evaluated by SEM. The results showed that the technique used was faithful and accurate on the reproduction of the ultrastructural details of the cervical region. The four types of morphological interrelationship among the hard tissues were found in the CEJ, in a irregularly and unpredictable distribution, because they showed from one to three of these interrelationships distributed on the same face, with a predominance of enamel overlapped by cementum (67.74%), followed by enamel and cementum edge-to-edge (56.45%), gaps between cementum and enamel (29.03%), and cementum overlapped by
enamel (8.06%), which appears in few and small portions of the CEJ. There was statistical association between the interrelationship cementum over enamel and pulpal normal condition and there was also at cementum over enamel a tendency to be present in teeth without endo-periodontal involvement. The presence of exposed dentin tubules was statistically significant in the group with endo-periodontal lesions. The NCCLs also
had statistically significant relationship in the group of teeth with severe periodontitis, with the predominance of saucer-shaped lesions in this group.
