The maxillary second molar contains three roots and three canals. Variations of the maxillary second molar are reported in numerous studies in vitro and in vivo. Dentists are required to have adequate knowledge related to root canal morphology and their possible variations. The aim of this study was to present a case report about a diagnosis and treatment in maxillary second molar with single root and single canal. It is concluded that the diagnosing of these unusual cases is of high importance for successful endodontic treatment of these teeth.

Objective: The aim of this study was to investigate, in vitro, the color changes of the teeth, induced by endodontic sealers. Materials and Methods: Forty-five mature maxillary and mandibular anterior teeth, extracted for periodontal reasons, were collected. After the chemo-mechanical instrumentation of the root canal, teeth were filled with four endodontic sealers (Endomethason, AH+, Canason and Apexit). Depending on canal sealers and the CEJ (Cement Enamel Junction), teeth were divided into 8 experimental groups (n = 5) and one control group/CG (n = 5). Teeth color changes (L*a*b*/CIE Commission Internationaled' Eclaraige) were determinated by a spectrophotometer Vita Easyshade in 4 stages (Baseline, Week 0, 4 and 12). Results: Between the EOCEJ and CG for the parameter L*, there was a statistical significance (p < 0.05). The L*a*b* results were: L* (82.5 ± 4.2 → 77.2 ± 1.2); a* (−2.38 ± 0.93 → 0.36 ± 1.41) and b* (15.5 ± 2.0 → 19.0 ± 3.2). For AOCEJ and CG there was not a statistical significance (p > 0.05). The L*a*b* results were: L* (83.6 ± 4.8 → 83.6 ± 4.9); a* (−2.68 ± 1.02 → −1.12 ± 0.72) and b* (20.2 ± 4.5 → 24.4 ± 4.2). Conclusions: All endodontic sealers may cause teeth discoloration.

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Background A hermetic seal at the apical terminus is required for healthy periradicular tissue. Root canal obturation sealers that are used in endodontics are based on zinc oxide eugenol, calcium hydroxide, resins, glass ionomers, silicone, or bioceramics, but no optimal sealer material has been identified to date. Therefore, the aim of this in vitro study was to evaluate apical leakage after crown-down preparation and root canal obturation with Endomethasone N, glass ionomer cement, and EndoRez sealers. Material/Methods For this in vitro study, we tested 92 extracted human teeth, which were divided into 3 groups after a preparation technique and obturation with Endomethasone N sealer, glass ionomer cement, and EndoRez sealer in combination with Thermafil obturator. Apical leakage was evaluated and compared among the tested groups using a dye leakage method through a stereomicroscope. The values were measured from the apex to the coronal extent of dye penetration. For statistical analysis, the t test was used for comparison of the arithmetic averages of tested groups. Results After preparation with rotary files, tested groups obturated with Thermafil obturator in combination with Endomethasone sealer showed higher average dye penetration than tested groups obturated with EndoRez and glass ionomer sealer. Conclusions Although all experimental groups showed dye leakage, the glass ionomer sealer in combination with Thermafil showed the least leakage, compared with EndoRez and Endomethason N.

The purpose of this study was to determine the levels of mercury in hard tissue from dental amalgam fillings under in vitro conditions. Methods and Results: The study included 30 human teeth that were extracted for various clinical reasons. The teeth were stored in a physiological solution until they were used. The teeth were divided into 3 experimental groups: Group 1 (n=10) – occlusal surface cavity preparation (class I according to Black); Group 2 (n=10) – proximal-occlusal surface cavity preparation (class II); and Group 3 (n=10) – mesio-occlusal-distal [MOD] surface cavity preparation. Each of these groups was divided into 2 subgroups: subgroup 1 (n=5) – amalgam fillings were not polished, and subgroup 2 (n=5) amalgam fillings were polished. The teeth were filled with amalgam, and those in subgroups 2 were polished after 24 hours. The amount of mercury released from the amalgam fillings was determined 9 months after the teeth were filled. Before chemical analysis, the teeth were irrigated 4 times over a period of 10 minutes in an ultrasonic bath. From each tooth, 250mg of the powder was mineralized with royal water (HCl+HNO3 in a ratio of 1:3) in a microwave oven, for 54 minutes. After mineralization, the samples were filtered and analyzed with inductively coupled plasma optical emission spectrometry. The average mercury level after polishing the amalgam filling was significantly smaller (P=0.032) only in Group 1. The average mercury levels in the 3 groups revealed significant differences between both the unpolished samples (one-way ANOVA F = 69.54, P < 0.001) and the polished samples (one-way ANOVA F = 110.54, P < 0.001). Group 3 with MOD surface cavity preparation was characterized by the highest mercury levels. Conclusion: The teeth with an MOD amalgam restoration are characterized by the highest mercury levels. The more mercury is released from unpolished amalgam fillings than from polished amalgam fillings in teeth with occlusal surface cavity preparation (class I according to Black).