Maxillary Premolars with Three Root Canals: A Case Report

The numerous difficulties found during root canal treatments are due to anatomical variations in the radicular morphology. Maxillary premolars have highly varied root canal systems and shapes. This case report addresses two endodontic treatment cases of the maxillary first and second premolars with three canals and a summary of their anatomical forms. The article describes the diagnosis and clinical management of these teeth

A Mandibular First Molar with Three Distal Canals: A Case Report and Literature Review

For a successful root canal treatment, it is critical for a clinician to have complete knowledge of the root canal morphology. There are numerous cases in literature concerning the unusual anatomy of mandibular first molars. This report presents a case of a mandibular first molar with three distal canals. An overview of the types and numbers of the common anatomic forms of this tooth also is presented, as is a summary of published anomalies.Key words: Distal Root; Mandibular First Molar; Root Canal Anatom

The effect of minimally invasive treatments on enamel microhardness and resistance to further demineralization

Objectives: The present study aimed to compare microhardness of inactive proximal lesions treated by resin infiltration, Er:YAG laser + resin infiltration and Bioactive glass, and investigate the resistance of treated lesions to further demineralization challenge. Methods: In this in-vitro study, 30 human molars with inactive proximal lesions were selected and randomly divided into three groups of 10. In group 1 (resin infiltration), the lesions were treated by a resin infiltrant (Icon). In group 2, the surface was conditioned by an Er:YAG laser prior to resin infiltration. The specimens in group 3 were remineralized by bioactive glass. The treated specimens were kept in artificial saliva for 1 week and then immersed in a demineralization solution for 8 weeks. Surface microhardness was measured at baseline (T0), after remineralization (T1) and after exposure to the demineralization solution (T2), and the difference in microhardness between time points (ΔVHN) was calculated. Results: Microhardness after demineralization (T2) was significantly lower than those of other intervals (P0.05). The statistical analysis revealed no significant difference either in ΔVHNT1-T0 or in ΔVHNT2-T1 among the study groups (P>0.05) Conclusion: Pretreatment by the Er:YAG laser prior to resin infiltration was more effective that other treatments in enhancing microhardness and protecting the tooth against acidic challenge. However, the difference between groups did not reach a statistical significance, implying the need for further studies to achieve more conclusive results

Do Different Tooth Bleaching–Remineralizing Regimens Affect the Bleaching Effectiveness and Enamel Microhardness In Vitro?

Objective. Tooth bleaching may negatively affect the enamel surface properties, such as reduction in hardness values, and remineralizing agents can reverse these effects. This study evaluated the effect of remineralizing agents before, during, and after the bleaching process on enamel’s whitening effectiveness and microhardness. Methods and Materials. The initial color of 104 bovine incisors after immersion in tea solution was recorded, and then, the teeth were randomly divided into eight groups (n = 13). Group 1 (NC) was considered the control with no treatment, and Group 2 (B) was bleached with 40% hydrogen peroxide gel. The 3% fluorohydroxyapatite (FHA) and 2% sodium fluoride (NaF) were applied before (FHA/B, NaF/B), during (FHA + B, NaF + B) and after (B/FHA, B/NaF) the bleaching process in other groups. The final color and microhardness in three depths of 20–30, 50–60, and 100–120 µm were measured. Data were analyzed using Shapiro–Wilk, one-way ANOVA, Tukey, Games Howell, repeated measurement, and LSD tests. Results. The FHA + B presented the lowest ΔE, significantly lower than other groups, except B/FHA. The ΔE in B/FHA was significantly lower than B/NaF. The bleaching significantly reduced the enamel hardness in three depths. The highest microhardness values were reported for B/NaF and NaF + B, which have no noticeable difference with NC, while FHA/B showed the lowest hardness in three depths, which was significantly lower than NC. Conclusion. The application of NaF before, during, and after the bleaching improved the microhardness of bleached enamel as the unbleached one with no adverse effect on whitening effectiveness