Journal of Dental Medicine

Background and Aims: Since a large marginal opening allows more plaque accumulation, gingival sulcular fluid flow and bone loss, microleakage, recurrent caries and periodontal disease, marginal fit is of great importance in fixed restorations. The aim of this study was to compare the marginal fit of zirconium-based all ceramic (Cercon) frameworks, made by two different approaches (Direct and Wax-up scanning).

Materials and Methods: An abutment analog, with 5.5 mm width and height, was selected as an experimental model. Twenty all ceramic cores were made for this model (10 specimens per each group). In the first group (Direct), experimental models were scanned directly using Computer Aided Design/Computer Aided Manufacturing (CAD/CAM). The core was then designed with the aid of a computer and machined. In the second group (Wax-up or CAM) a wax-up pattern was made on the experimental model and then scanned and milled from Cercon blocks. The marginal discrepancy of each specimen was recorded using a stereomicroscope (SZX9, Olympus, Japan) and digital camera (Mode TK, C1380E, JVC, Japan) and then measured by Adobe Photoshop CS software. The data were analyzed using T-test.

Results: Mean marginal discrepancy of Direct group (85.2±3.95 µm) was significantly less than that of Wax-up group (120.2±6.91 µm).

Conclusion: Improved marginal fit of zirconia ceramics was found with the direct model scanning compared with that of Wax-up scanning using CAD/CAM.

Background and Aims: Apoptosis or programmed cell death plays an important role in the pathogenesis of many diseases. Previous studies suggest that apoptosis is involved in the pathogenesis of periodontal disease, on the other hand it is also suggested that diabetes mellitus enhances apoptosis of connective tissue cells. Thus, we measured expression of proteins which are relevant to apoptosis in the gingival tissue of diabetic patients with chronic periodontitis in comparison to non diabetic individuals.

Materials and Methods: 25 patients with diabetes and chronic periodontitis and 16 non diabetic controls were included in this study. 4 weeks after scaling and root planning and oral hygiene instructions, periodontal surgery was done and gingival tissues obtained during surgery, were sent to lab to investigate expression of Fas, P53, Bcl-2 and Survivin using real-time PCR technique. Data were analyzed using Mann-Whitney and Chi-squared.

Results: Pro-apoptotic proteins (Fas, P53) were significantly (P<0.05) higher in gingival tissues of diabetics (9.5×10^-6, 2.4×10^-6, respectively) in comparison to non diabetics (9.4×10^-7, 5.6×10^-7), whereas the difference in expression of anti-apoptotic proteins (Bcl-2, Survivin) between 2 groups was not significant (9.7×10^-8, 3.5×10^-7 in comparison to 1.4×10^-7, 3.1×10^-7, respectively)( P =0.91, P =0.29 respectively).

Conclusion: Apoptosis was increased in gingival connective tissue of diabetic patients with chronic periodontitis in comparison to non diabetic ones. Therefore , intervention in expression or function of pro-apoptotic proteins (Fas, P53) could be a new goal in the treatment of periodontal disease of diabetic patients.