Effect of chitosan on osteogenic properties of mesenchymal stem cell of exfoliated deciduous teeth

The exfoliated human deciduous tooth contains multipotent stem cells [Stem Cell from Human Exfoliated Deciduous tooth [SHED]] that identified to be a population of highly proliferative and clonogenic. These cells are capable of differentiating into a variety of cell types including osteoblast/osteocyte, adiopcyte, chondrocyte and neural cell. The aim of this study was to evaluate the differentiation of SHED to osteoblast in standard osteogenic medium and comparing the results with medium which supplemented with glucosamine in form of chitosan. Dental pulp cells were isolated from freshly extracted primary teeth, digested with 4 mg/ml collogenase/dispase, and grown in Dulbecco's modified Eagle's medium with 10 percent fetal bovine serum. The clonogenic potential of cells was performed after 3 weeks of culture. Flowcytometric analysis, performed at day 21 of culture to identify surface markers of mesenchymal stem cells. The cells from 3rd passage were used for osteogenic differentiation in routine osteoinductive medium. Chitosan [10 microg/ml] was added to the culture medium of case group. Alizarin Red Staining and Alkaline Phosphatase [ALP] activity were done to evaluate osteogenic differentiation in the developing adherent layer on the third passage. The results were analyzed using T-test. For the analysis of normal distribution of data, non-parametric Kolmogrov-Smirnov test was used. The colonogenic efficiency was more than 80%. Flowcytometric analysis showed that the expression of mesenchymal stem cell marker CD90, CD 105 and CD146 were positive in SHED, while hematopoietic cell marker CD34, CD45 and endothelial cell marker CD31 were negative. Quantitative analysis of Alizarin Red Staining demonstrated that: mineralized nodule formation was higher in the group supplemented with glucosamine [chitosan]. Results from Alkaline Phosphatase activity test, on day 21, demonstrated a significantly higher ALP activity in the group supplemented chitosan [P<0.001]. Stem cells isolated and cultured from exfoliated deciduous teeth pulp can be differentiated to osteoblast. Addition of chitosan can be beneficial to promote osteogenic differentiation of these cells

Clinical evaluation of the accuracy of Raypex 5 electronic apex locator on root canal length determination in primary teeth

Radiographic usage for determination of working length is difficult in children, because of hazardous irradiation, superimposition of the permanent tooth germ and primary tooth root, mouth opening limitation, lack of cooperation, and radiographic misinterpretation of primary teeth. The purpose of this clinical study was to evaluate the accuracy of the Raypex 5 apex locator for root canal length determination in primary teeth. This experimental study used 23 primary second molar teeth that were scheduled for extraction. Following access cavity preparation, the working length was determined with a Raypex5 electronic apex locator. The teeth were extracted and real lengths of root canals were measured with insertion of a K-type file into each canal until it emerged at the apical foramen. This length, minus 0.5 mm, was recorded as the real root canal length. The data were statistically analyzed using a One Sample /-test. The accuracy of the Raypex 5 electronic apex locator in determining working length within 0.5 mm of the real length was 81.2% and 100% within 1mm of the real length. This study concluded that the Raypex 5 apex locator is a useful tool for measuring root canal lengths in primary teeth