RESUMO
Maxillary incisors are typically straightforward cases for root canal therapy. While it is commonly assumed that maxillary central incisors have a single root canal, they may occasionally exhibit variations in their root canal system anatomy. In this report, we present a case of a maxillary central incisor with multiple root canals and provide a review of relevant literature on this anatomical variation. A 13-year-old female with deep carious lesion in tooth 11 was admitted in Department of Endodontics. Following a precise clinical and radiographic examination, a maxillary central incisor with necrotic pulp and chronic apical periodontitis along with unusual root anatomy was found and considered for non-surgical root canal treatment. Successful treatment results depend on various factors and awareness of root canal system anatomy is one of them. Due to an increasing number of reported cases of maxillary central incisors with different anatomy, it is imperative to consider anatomical variations even in the most routine cases.
RESUMO
Background. This in vitro study aimed to evaluate the microshear bond strength (µSBS), microhardness and morphological characteristics of primary enamel after treating with sodium fluoride (NaF) and acidulated phosphate fluoride (APF). Methods. Forty-eight primary canines were cut into mesial and distal sections and assigned to five groups randomly: group 1 (immersed in saliva as a control), group 2 (treated with NAF and immersed in saliva for 30 minutes), group 3 (treated with APF and immersed in saliva for 30 minutes), group 4 (treated with NAF and immersed in saliva for 10 days), and group 5 (treated with APF and immersed in saliva for 10 days). Composite resin (Filtek Z250) was bonded on the specimens (n=15) for measuring the µSBS. After storage in 37°C artificial saliva for 24 hours, µSBS and Vickers hardness tests (10 readings) were performed. The data were analyzed using one-way ANOVA and Kolmogorov-Smirnov, Levene's and Tukey HSD tests (P<0.05). Morphological analysis of enamel and modes of failure were carried out under a scanning electron microscope (SEM) on two remaining specimens. Results. Significant differences in µSBS were only noted between groups 2 and 4 (P=0.024). Group 3 showed a significant decrease in hardness after storage in artificial saliva (P<0.001), with a significantly lower hardness than the other groups (P<0.001). The SEM observations showed irregular particles in groups 3 and 5; uniform, smooth and thin coats were seen in groups 2 and 4. Conclusion. Fluoride therapy with NaF and APF gels prior to restorative treatments had no adverse effects on the microshear bond strength.
