[Evaluation of adhesion and morphologic changes of human osteoblasts exposed to gray MTA, white MTA and Portland cement]

Osteoblasts and periodontal ligament cells play a major role in wound healing after root end resection. The interaction of osteoblasts with filling materials is critical in healing of surgical lesions. The aim of this study was to evaluate the morphology and adhesion of human osteoblasts [MG-63 cell line] in contact with IRM, gray MTA, white MTA and Portland cement [PC] as root end filling materials. In this in vitro study, human osteoblasts of osteosarcoma were provided from the cell bank of Iran Pasteur Institute, and cultured in RPMI 1640 medium. Test materials were mixed according to the manufacturer's instructions and placed in contact with osteoblast cells. After the first, third and seventh days discs of materials with grown cells were fixed and examined by scanning electron microscopy. Results showed that after 7 days most of the osteoblasts were attached to the surface of both gray and white MTA and PC and appeared flat or round, however cells adjacent to IRM were round without any adhesion and spread. Based on the results of this study, human osteoblasts have a favorable response to gray and white MTA and Portland cement compared to IRM

[Mental health and psychological consequences of chronic low back pain in a group of Iranian labors]

The present study examines the mental health of labors diagnosed with CLBP in one of the Iranian industrial factory as one of the top ranked factories in the Middle-East. In all, 45 people with CLBP and 72 controls were entered into the study. The General Health Questionnaire [GHQ-28] and a pain questionnaire were administered to assess mental health and pain intensity. Findings showed a significant difference between the two groups; the overall level of mental health in CLBPP was significantly lower than the control group. However, no significant difference was shown in the Social Dysfunctional [SD] subscale, CLBP patients showed a noticeable difference in the rest subscales. Patients with more sick leave, showed more anxiety, depression and social dysfunction. In addition, there were significant difference in the sleep disorder, fatigue and job satisfaction between CLBP patients and control group but no significant difference was shown in the smoking. According to our hypothesis, CLP impressed mental health in more aspects; anxiety and depression as two important factors for disability are related to sick leave and job satisfaction. Main results of the present study are congruent with the previous researches in this field

[ comparative study on the tensile strength of 3 luting cements: zinc phosphate, gloss ionomer and core maxII in the retention of custom posts [research]]

Post retention in endodontically treated teeth is an important factor in post-core technique. One of the factors effective in post retention is the type of applied luting cement. The goal of this study was to compare the tensile strength of 3 luting cemnts: zinc phosphate, glass ionomer and Core max II in the retention of custom posts. In this study, 33 extracted maxillary central incisors, of the similar dimensions, were selected and divided into three groups randomly. All the teeth crowns were cut at 2 mm above CEJ. Following standard 2 root canal therapy, 2/3 of the canal space was enlarged with pizo reamer No 2 and 3. The length of posts were 12 mm. Acrylic resin patterns, of the same dimensions, were made for all samples. In order to do the tensile strength test, a hole with the diameter of 2 mm was prepared on the crown of each tooth. Castings were fabricated using silver cast alloy, Then each group was cemented with one of the studied cements. Following cementation, the tensile strength of posts was measured using the instron testing machine. In order to analyze the data, using SPSS software, one-way variance analysis test was used and for parried comparisons t-student test was used [P=0.05]. No statistically significant differences were found in the tensile strength of glass ionomer [29.11 kg] and zinc phosphate [29.19kg] [P=0.97], whereas both of these cements showed significantly higher tensile strength than Core maxII [11-56Kg] [P=0.000]. It is concluded that the retention of posts luted with glass ionomer and zinc phosphate are higher than Core max II