Light and SEM observation of internal root resorption of a traumatized permanent central incisor

Diagnostic accuracy of phosphor plate systems and conventional radiography in the detection of simulated internal root resorption

OBJECTIVE

To evaluate the performance of conventional radiography and photostimulable phosphor (PSP) plate in the detection of simulated internal root resorption (IRR) lesions in early stages.

MATERIALS AND METHODS

Twenty single-rooted teeth were X-rayed before and after having a simulated IRR early lesion. Three imaging systems were used: Kodak InSight dental film and two PSPs digital systems, Digora Optime and VistaScan. The digital images were displayed on a 20.1″ LCD monitor using the native software of each system, and the conventional radiographs were evaluated on a masked light box. Two radiologists were asked to indicate the presence or absence of IRR and, after two weeks, all images were re-evaluated. Cohen's kappa coefficient was calculated to assess intra- and interobserver agreement. The three imaging systems were compared using the Kruskal-Wallis test.

RESULTS

For interexaminer agreement, overall kappa values were 0.70, 0.65 and 0.70 for conventional film, Digora Optima and VistaScan, respectively. Both the conventional and digital radiography presented low sensitivity, specificity, accuracy, positive and negative predictive values with no significant difference between imaging systems (p = .0725).

CONCLUSIONS

The performance of conventional and PSP was similar in the detection of simulated IRR lesions in early stages with low accuracy.

Clinical and scanning electron microscopic features of invasive cervical resorption in a maxillary molar

This case report presents clinical and morphological features of severe invasive cervical resorption (ICR) involving a maxillary first molar. Surface morphology of the ICR defect that extended into enamel was studied using a scanning electron microscope. The topography and morphology of resorbed enamel and pulpal surfaces are described. The pulpal space was characterized by proliferation of fibrovascular tissue invaded by a number of > or = 15-microm-large dentinoclastlike cells. The vertical orientation and hexagonal geometric outlines of enamel rods indicated that the resorptive defect had extended into the outer surface of enamel. Preferential odontoclastic dissolution of interprismatic enamel was noted. Deposits of a cementumlike substance were noticed on enamel surfaces, indicating that resorptive process was coupled with repair. Complete destruction of dentin was associated with no response by the tooth to cold stimulus, supporting the hydrodynamic theory of dentinal sensitivity. The results of this study indicate that in addition to predentin and cementum, the outer surface enamel may be resistant to the resorptive process as well.

Internal root resorption studied by radiography, stereomicroscope, scanning electron microscope and computerized 3D reconstructive method

AIM AND METHODOLOGY

Two cases of internal tooth resorption were examined. A mandibular premolar and a mandibular canine were studied after they were extracted using radiographs, a stereomicroscope (SM) and a scanning electron microscope (SEM). Lastly, 3D images of the sectioned teeth were obtained(3D).

RESULTS

Radiographically, internal root resorption was shown as a uniform radiolucency. By SM examination, an extensive destruction of dentin was seen, while, by SEM examination, a disappearance of dentinal tubules was clear. The 3D reconstructive method revealed a circumscribed, oval-shaped defect that did not perforate the cemental layer.

CONCLUSIONS

Internal root resorption is a rare remodeling process that can be studied using different experimental methods.