Effect of Sprue Design in Nickel-Chromium Cast Crown Margin

ABSTRACT Objective: To determine the effect of sprue design on the marginal accuracy of the casting. Material and Methods: It was an experimental in-vitro study. There are forty-four crowns of single sprue group with a forty-four double sprue group that was compared in 6 different locations of the margin. The sections were inspected under a microscope at 50X magnification and took a micrograph. The radius from an actual casting edge to a possibly excellent margin was then documented as marginal discrepancy (d), in µm. The marginal discrepancy was documented for each of the six sections per casting. Thus 264 sections were measured for each group. Data were analysed using (ANOVA) for analysis of variance. For bivariate analyses, Chi-square and Student t test were used. The significance level was set at < 0.05. Results: The marginal discrepancy was greater in the single sprue group of cast crown (43.1 ± 4.74 µm) and in double sprue group of cast crown was less (25.7 ± 4.25 µm). This difference is statistically significant (p<0.05). The correlation between single sprue group of casting with a double sprue group of casting by student's t-test where determination height was 95%. Conclusion: Double sprue design produces a higher accurate margin than single sprue design in the nickel-chromium alloy cast crown.

Fresh Frozen Amniotic Membrane and Buccal Pad of Fat for Reconstruction of Oral Mucosal Defect After Surgical Excision of Leukoplakia

Objective: To compare the use of Fresh Frozen Amniotic Membrane (FFAM) and Buccal Pad of Fat (BPF) for reconstruction of oral mucosal defect after surgical excision of leukoplakia. Material and Methods: Twenty patients were randomly selected and divided into two groups. Group 1 use amniotic membrane graft and Group 2 BPF. Both groups were evaluated preoperatively and postoperatively. Incisal opening, epithelialization and fibrosis were evaluated after one month of surgery. Chi square and Student t tests were used. Results: According to the presence of smoking habits, the highest frequencies were for smoking (30%) and betel leaf areca nut with tobacco (30%). Regarding the diameter of oral leukoplakia, in 40% of the participants it was 2x3 cm2. In Group1, after one month of surgery preoperative and postoperative inter-incisal opening values were 44.20 ± 3.37 and 42.05 ± 3.47 (p<0.001). In Group 2, preoperative and postoperative inter-incisal opening values were 44.09 ± 3.32 and 43.01±3.38 (p>0.05). When FFAM was used complete epithelialization in 70% and incomplete epithelialization in 30% patients. When BPF was used the results were almost similar. Fibrosis occurred in 30% in Group 1. There were no complications like flap necrosis, infectiona and hematoma formation. Conclusion: Incisal opening was significantly better in Fresh Frozen Amniotic Membrane Group, epithelialization and fibrosis were almost same in both groups after surgical excision of oral leukoplakia.

Comparative Study Between Standard Ward's Incision and Coma Shaped Incision and its Postoperative Outcome on Impacted Mandibular Third Molars Extraction in Bangladeshi Population

Objective: To evaluate the postoperative outcome in standard Comma Shaped incision and Ward's incision on postoperative complications in surgical removal of impacted mandibular third molar. Material and Methods: In this study, 100 patients with impacted mandibular third molar were selected for study. The patients were divided in to two groups. Each group contains 50 patients. A standard Ward's incision was made on one group and a Comma incision was made on another group to reflect the mucoperiosteal flap, after the common steps for removal of impacted third molars were followed. The postoperative parameters were recorded immediately on the postoperative days 1, 3 and 7. For bivariate analyses, Chi square and Student t test were used. The significance level was set at 5%. Results: The pain and swelling scores were found to be significantly lower in the surgical area with Comma incisions, which was recorded on days 1, 3 and 7 as compared to the area where standard Ward's incision were made. In mouth opening, there was a sufficiently great difference seen between the two incisions on first postoperative day, but on day 3 and 7 there was no statistical significance. Conclusion: the Comma Shaped incision design was preferable over the standard Ward's incision, considering the lesser degree of postoperative complications.