[Misinterpretation of a periapical radiograph: the canalis sinuosus mimicking a root resorption]

There is widespread knowledge that the mental foramen or incisive foramen can be projected onto tooth roots in conventional radiographs, thus simulating apical lesions. In contrast, the anatomical structure of the canalis sinuosus and its branching canals in the anterior maxilla are less known. Sometimes these bone canals mimic a dentino- or osteolysis on conventional radiographs. If these bone canals project onto the roots of the anterior maxillary teeth, there is a risk of misinterpretation as root resorption or apical periodontitis. This case report presents an incidental radiological finding. Due to a radiolucency within the root of tooth 11, root resorption was suspected. Using cone beam-computed tomography, the origin of this radiolucency was clearly identified as an anatomical structure, and the suspected diagnosis was ruled out. This case highlights the importance of the knowledge of anatomical structures to avoid misinterpretations and unnecessary treatments.

Impact of the in situ formed salivary pellicle on enamel and dentine erosion induced by different acids

OBJECTIVE

To investigate and compare the protective impact of the in situ formed salivary pellicle on enamel and dentine erosion caused by different acids at pH 2.6.

METHODS

Bovine enamel and dentine samples were exposed for 120 min in the oral cavity of 10 healthy volunteers. Subsequently, enamel and dentine pellicle-covered specimens were extraorally immersed in 1 ml hydrochloric, citric or phosphoric acid (pH 2.6, 60 s, each acid n=30 samples). Pellicle-free samples (each acid n=10) served as controls. Calcium release into the acid was determined by atomic absorption spectroscopy. The data were analysed by two-way ANOVA and Tukey's test (alpha=0.05).

RESULTS

Pellicle-covered samples showed significantly less calcium loss compared to pellicle-free samples in all acid groups. The mean (SD) pellicle protection (% reduction of calcium loss) was significantly better for enamel samples [60.9 (5.3)] than for dentine samples [30.5 (5.0)], but revealed no differences among the acids.

CONCLUSION

The efficacy of the in situ pellicle in reducing erosion was 2-fold better for enamel than for dentine. Protection of the pellicle was not influenced by the kind of acid when enamel and dentine erosion was performed at pH 2.6.