Purpose: The goal of this in vitro study was to identify the topographical features of the enamel surface deproteinized and etched with phosphoric acid (H3PO4) compared to phosphoric acid alone. Materials and method: Ten extracted lower first and second permanent molars were polished with pumice and water, and then divided into 4 equal buccal sections having similar physical and chemical properties. The enamel surfaces of each group were subjected to the following treatments: Group A: Acid Etching with H3PO4 37% for 15 seconds. Group AH1: Sodium Hypochlorite (NaOCl) 5.25% for 30 seconds followed by Acid Etching with H3PO4 37% for 15 seconds. Group AH2 ; Sodium Hypochlorite (NaOCl) 5.25% for 60 seconds followed by Acid Etching with H3PO4 37% for 15 seconds. Results showed that group AH2 etching technique reached an area of 76.6 mm2 of the total surface, with a 71.8 mm2 (94.47%), type 1 and 2 etching pattern, followed by group AH1 with 55.9 mm2 out of 75.12 mm2 (74.1%), and finally group A with only 36.8 mm2 (48.83%) out of an area of 72.7 mm2. A significant statistical difference (P <0 .05) existed between all groups, leading to the conclusion that enamel deproteinization with 5.25% NaOCl for 1 minute before H3PO4, etching increases the enamel conditioning surface as well as the quality of the etching pattern.

Purpose: The goal of this in vitro study was to identify the topographical features of deproteinized (NaOCl)and etched with phosphoric acid (H3PO4) enamel surface, compared to phosphoric acid surface alone with a Resin Replica model. Materials: Ten extracted lower first and second permanent molars were polished with pumice and water, and then divided into 3 equal buccal sections having similar physical and chemical properties. The enamel surfaces of each group were subjected to the following treatments: Group A: Acid Etching with H3PO4 37% for 15 seconds. Group B: Sodium Hypochlorite (NaOCl) 5.25% for 60 seconds followed by Acid Etching with H3PO4 37% for 15 seconds. Group C; No treatment (control). All the samples were treated as follow: Adhesive and resin were applied to all groups after A, B and C treatment were performed; Then enamel/dentin decalcification and deproteinization and topographic SEM Resin Replica assessment were used to identify resin tags enamel surface quality penetration. Results showed that group B reached an area of 7.52mm2 of the total surface, with a 5.68 mm2 (73%)resin tag penetration equivalent type I and II etching pattern, 1.71 mm2 (26%) equivalent to type III etching pattern and 0.07 mm2 (1%)unaffected surface. Followed by group A with 7.48 mm2 of the total surface, with a 3.47 mm2 (46 %)resin tag penetration equivalent to type I and II etching pattern, 3.30 mm2 (45 %)equivalent to type III etching pattern and 0.71 mm2, and (9 %) unaffected surface. Group C did not show any resin tag penetration. A significant statistical difference (P <0,001) existed between groups A and B in resin quality penetration, leading to the conclusion that when the enamel is deproteinizated with 5.25% NaOCl for 1 minute prior H3PO4,the surface and topographical features of the replica resin penetration surface increases significantly with type I-II etching pattern.

Electronic apex locators (EAL) have been used to establish the working length (WL) in root canal treatment. In teeth diagnosed with apical periodontitis, resorption of tooth apical structures can lead to difficulties to obtain an appropriate WL. The aim was to compare the capacity of three EAL’s (Root ZX II, Raypex 6 and Endo-Eze Quill) to locate the tip of the K-file between 0 to -0.5 mm from the apical foramen (AF) on teeth diagnosed with asymptomatic apical periodontitis (AAP). Electronic working length was performed on 60 roots with AAP. A K-file #15 was inserted in the root canal until the apical foramen (AF) was located, and followed was re-adjusted to -0.5 mm through observation in EAL display. The K-file was fixed to the tooth with composite and teeth were extracted. The 4 apical millimeters were worn out until the K-file could be seen and were prepared and measured its distance to AF in a scanning electron microscope. Appropriate WL was when the tip of the K-file was located between 0 to -0.5 mm from AF. Results: Root ZX II showed significant difference (p<0.01) with the other two EALs. Root ZX II presented the better performance than Raypex 6 or Endo-Eze Quill in teeth with AAP.

Introduction: Dental fusion is a developmental anomaly in which two teeth buds join each other at different levels. Objective: To report a case of a lower canine and a lower lateral incisor with separate crowns and root fusion, with root canals connected and apical periodontitis. Methods: One year earlier, the patient had received root canal treatment in the canine; however, there was no remission of symptoms. Endodontic treatment was performed with reinstrumentation, passive ultrasonic irrigation with sodium hypochlorite, smear layer removal and intracanal medication with calcium hydroxide. A week later, the symptoms had disappeared and the canals were filled with gutta-percha and Sealapex by means of the Tagger hybrid technique. Results: After two years and two months, the patient exhibited periapical tissues healing. Conclusion: The detection and proper management of developmental tooth anomaly cases is mandatory for treatment success.