Evaluation of gingival displacement, bleeding and ease of application for polytetrafluoroethylene (PTFE) and conventional retraction cord - a clinical trial.

OBJECTIVE: Conventional use of retraction cord in soft tissue management is effective only when the non-resilient nature of material does not jeopardize gingival health. Therefore this study aims to clinically evaluate the gingival displacement, ease of application and bleeding from polytetrafluoroethylene (PTFE) retraction cord. PATIENTS AND METHODS: This study is a single-center, parallel-group, randomized controlled clinical trial (1:1). Sixty patients indicated for full coverage metal-ceramic restoration for first molars were enrolled and randomly allocated to experimental (PTFE Cord) and control (conventional plain retraction cord) groups. After crown preparation and isolation, a pre-displacement impression was made. Assigned gingival displacement material was applied for 5 minutes, followed by post-displacement impression. Casts were prepared and used for assessment of mean horizontal gingival displacement by measuring displacement using a stereomicroscope (20 x). Post-displacement gingival bleeding and ease of application were also assessed clinically. t-test and Chi-square tests were used for statistical assessment of gingival displacement, gingival bleeding and ease of application. RESULTS: Gingival displacement, bleeding and ease of application were similar among study groups (p > 0.05). Mean gingival displacement in the experimental group was 197.1 µm, and 167.7 µm in the control group. Bleeding was observed in 30% and 20% of cases of experimental and control group, respectively. Ease of application was 'difficult' in 53.3% and 43.3% of cases of experimental and control group, respectively. Non-impregnated gingival retraction cord and PTFE cord displayed similar outcomes of gingival displacement, ease of placement and bleeding after cord removal. CONCLUSIONS: Post-displacement bleeding and discomfort for PTFE cord placement suggest that this technique needs improvement. Therefore further studies are warranted to improve and investigate the physical and biological response to PTFE retraction cord.

The diagnostic value of a panel of serological markers in acute appendicitis.

BACKGROUND: Appendicitis is a frequent reason for hospital admissions. Elevated C-reactive protein, white blood cell count, and serum bilirubin have been suggested as individual markers for appendicitis and appendiceal perforation. The aim of this study was to analyze if a combination of serologic markers could increase the prognostic accuracy of diagnosing non-perforated and perforated appendicitis. MATERIAL AND METHODS: Demographic data, histological findings, blood tests, and clinical symptoms were collected on all patients who underwent a diagnostic laparoscopy, a laparoscopic appendectomy, or conventional (open) appendectomy between May 2009 and May 2012 from a surgical department. The patients were grouped into those with either perforated appendicitis, non-perforated appendicitis, or differential diagnosis. Univariate and multivariate models were used to identify which markers were useful in predicting acute and perforated appendicitis, and receiving operating characteristics curves were used to find the specificity, sensitivity, and the negative and positive predictive values. RESULTS: A total of 1008 patients were operated under suspicion of appendicitis. From these, 700 patients had a pathologically verified inflamed appendix and 190 had a perforated appendix. Patients with acute appendicitis had significantly higher blood levels of white blood cell, bilirubin, C-reactive protein, and alanine transaminase than patients without appendicitis. Patients with perforated appendicitis had significantly higher levels of white blood cell, bilirubin, and C-reactive protein than patients with non-perforated appendicitis. The highest positive predictive value to discriminate between acute appendicitis and non-appendicitis was of a linear regression model combining white blood cell count, bilirubin, and alanine transaminase. C-reactive protein levels and a linear regression model, including white blood cell count, bilirubin, and C-reactive protein levels as variables, had the highest negative predictive values when discriminating between perforated and non-perforated appendicitis. CONCLUSION: Combining blood markers was useful in predicting appendicitis and perforated appendicitis. In addition to C-reactive protein and white cell count, blood levels of bilirubin, and alanine transaminase may be useful.