To investigate the levels of seven elements using an inductively coupled plasma-mass spectrometry (ICP-MS) method in rat organs after the implantation of Micro Mega Mineral Trioxide Aggregate (MM-MTA), Bioaggregate (BA) and Biodentine (BD) materials. MM-MTA, BA and BD were implanted into the subcutaneous tissue of 15 Wistar albino rats; three control animals had no operation. After 45 days, the rats were sacrificed and their brains, kidneys and livers were removed. The ICP-MS analysis was used to determine trace elements. Data were analysed using the Kruskal-Wallis and Connover post hoc tests. There was no significant difference between the control groups and the MM-MTA, BA and BD groups according to the concentration of aluminum, calcium, arsenic and lead in the rats' organs. Beryllium was not detected in all tissue samples. Chromium levels of these materials were higher than the control group in brain and kidney samples (P = 0.038 and P = 0.037); magnesium levels were higher than the control group in kidney and liver samples (P = 0.030 and P = 0.008). MM-MTA, BA and BD were nontoxic according to trace element levels in brain, kidney and liver samples of rats. Further investigation is required to understand the systemic effects of these materials.

The aim of this study was to compare the efficacy of D-RaCe files and a self-adjusting file (SAF) system in removing filling material from curved root canals instrumented and filled with different techniques by using microcomputed tomography (micro-CT). The mesial roots of 20 extracted mandibular first molars were used. Root canals (mesiobuccal and mesiolingual) were instrumented with SAF or Revo-S. The canals were then filled with gutta-percha and AH Plus sealer using cold lateral compaction or thermoplasticized injectable techniques. The root fillings were first removed with D-RaCe (Step 1), followed by Step 2, in which a SAF system was used to remove the residual fillings in all groups. Micro-CT scans were used to measure the volume of residual filling after root canal filling, reinstrumentation with D-RaCe (Step 1), and reinstrumentation with SAF (Step 2). Data were analyzed using Wilcoxon and Kruskal-Wallis tests. There were no statistically significant differences between filling techniques in the canals instrumented with SAF (P = 0.292) and Revo-S (P = 0.306). The amount of remaining filling material was similar in all groups (P = 0.363); all of the instrumentation techniques left filling residue inside the canals. However, the additional use of SAF was more effective than using D-RaCe alone.

Introduction. This clinical case report presents the successful endodontic treatment of a maxillary second molar that has a mandibular molar-like anatomy with no palatal root and with each of its roots containing two separate root canals. Cone-beam computed tomography (CBCT) was used to confirm this unusual anatomy. Methods. A 34-year-old male patient was referred to the Department of Endodontics at Inonu University's Faculty of Dentistry because of severe pain in his right maxillary second molar. Clinical and radiographic examinations identified unusual roots and root canals anatomy, and CBCT was planned in order to understand the nature of these variations. Cleaning and shaping procedures were performed using the crown down technique with Sybron Endo (Glendora, CA, USA) rotary instruments, and endodontic treatment was completed with gutta-percha cones and AH Plus resin sealers using the cold lateral compaction technique. Conclusions. The maxillary second molar exhibits aberrations and variations in terms of the numbers and configurations of its roots and root canals, and CBCT can be a useful imaging technique in endodontics.

Operative dental procedures may promote pulpal infections, such as tooth cavity, trauma and teeth abrasion, anaerobic microorganism colonization causing total pulp necrosis, and periapical lesions that result in bone destruction in the periapical region. Periapical radiographs are important tools for identifying periapical pathologies. However, given that the imaging system shows three-dimensional formations in two dimensions, the knowledge about the actual size of the lesion and the real relationship with the anatomic structures is limited. These limitations force clinicians to choose the high resolution and current imaging methods that show all the details of the oral structures, such as conic beam computed tomography (CBCT). CBCT is a highly effective diagnostic device for early period bone lesion detection in which the gray value for bone density is measured in Hounsfield unit (HU). Other than using CBCT, bone mineral density measurement can be done to assess the healing of existing lesions. When the periapical lesion is healing, a series of formation and destruction processes follow each other. On the one hand, mediators and tissues that must be removed from the region are destroyed by host defense cells; on the other hand, cells included in the repair process provide new tissue generation and remodelling to provide the pre-disease anatomic properties in the lesion region. This review discusses recent studies using current three-dimensional imaging methods, compared with traditional methods for bone damage due to periapical lesion formation and healing after suitable treatment. This study aims to investigate the advantages and shortcomings of existing treatment and diagnosis approaches in endodontic periradicular lesion diagnosis and treatment. The findings highlight promising diagnosis and treatment tools and suggest the expansion of minimally invasive approaches to eliminate the problems in periapical lesions.   How to cite this article: How to cite this article: Akın Tartuk G, Tekin Bulut E. The effects of periapical lesion healing on bone density. Int Dent Res 2020;10(3):90-9. https://doi.org/10.5577/intdentres.2020.vol10.no3.5   Linguistic Revision: The English in this manuscript has been checked by at least two professional editors, both native speakers of English.

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