A method for retrieving endodontic or atypical nonendodontic separated instruments from the root canal: a report of two cases.

AIM: This clinical report presents a new method for retrieving separated instruments from the root canal with minimally invasive procedures. BACKGROUND: The presence of separated instrument in root canal may interfere in the endodontic treatment prognosis. There are several recommended methods to retrieve separated instruments, but some are difficult in clinically practice. CASE REPORT: This study describes two cases of separated instrument removal from the root canal using a stainless-steel prepared needle associated with a K-file. Case 1 presented a fractured gutta-percha condenser within the mandibular second premolar, it was separated during incorrect intracanal medication calcium hydroxide placement. Case 2 had a fractured sewing needle within the upper central incisor that the patient used to remove food debris from the root canal. After cervical preparation, the fractured instruments were fitted inside a prepared needle and then an endodontic instrument (#25 K-file) was adapted with clockwise turning motion between the needle inner wall and the fragment. CONCLUSION: The endodontic or atypical nonendodontic separated instrument may be easily pull on of the root canal using a single and low cost device. CLINICAL SIGNIFICANCE: The methods for retrieving separated instruments from root canal are difficult and destructive procedures. The present case describes a simple method to solve this problem.

Human Dental Pulp Cells: A New Source of Cell Therapy in a Mouse Model of Compressive Spinal Cord Injury

Strategies aimed at improving spinal cord regeneration after trauma are still challenging neurologists andneuroscientists throughout the world. Many cell-based therapies have been tested, with limited success in termsof functional outcome. In this study, we investigated the effects of human dental pulp cells (HDPCs) in a mousemodel of compressive spinal cord injury (SCI). These cells present some advantages, such as the ease of theextraction process, and expression of trophic factors and embryonic markers from both ecto-mesenchymal andmesenchymal components. Young adult female C57/BL6 mice were subjected to laminectomy at T9 andcompression of the spinal cord with a vascular clip for 1 min. The cells were transplanted 7 days or 28 days afterthe lesion, in order to compare the recovery when treatment is applied in a subacute or chronic phase. Weperformed quantitative analyses of white-matter preservation, trophic-factor expression and quantification, andultrastructural and functional analysis. Our results for the HDPC-transplanted animals showed better whitematterpreservation than the DMEM groups, higher levels of trophic-factor expression in the tissue, better tissueorganization, and the presence of many axons being myelinated by either Schwann cells or oligodendrocytes, inaddition to the presence of some healthy-appearing intact neurons with synapse contacts on their cell bodies. Wealso demonstrated that HDPCs were able to express some glial markers such as GFAP and S-100. The functionalanalysis also showed locomotor improvement in these animals. Based on these findings, we propose that HDPCsmay be feasible candidates for therapeutic intervention after SCI and central nervous system disorders inhumans.