The effectiveness of a novel optical probe in subgingival calculus detection.

OBJECTIVES: The aim of the present study was to evaluate the effectiveness of a novel optical calculus detection system under in vivo conditions. METHODS: One hundred and seventy-six tooth surfaces from 44 adult teeth that were indicated for extraction were selected for the present study. The patients were randomly assigned to one of the two experimental groups. In group A (n = 96), clinical presence or absence of subgingival calculus deposits was determined using the light-emitting diode-based optical probe (OP). In group B (n = 80), the subgingival deposits were first recorded with the OP followed by root surface debridement until no subgingival deposits could be detected by the device. Teeth were then extracted and examined under a stereomicroscope by two trained dentists (DENT 1, DENT 2) and a dental student. Results were compared with the measurements of the OP and direct visual control. RESULTS: In group A, post-extraction results revealed 89% and 90% agreement with the positive and negative OPs detection. In group B, 17% of the surfaces demonstrated even after subgingival debridement and control with the detecting device still calcified deposits in the microscopic evaluation. The highest inter-examiner agreements were observed between DENT 1 and DENT 2. CONCLUSION: It was shown that the optical detection system identifies subgingival calculus with a high efficacy and therefore, may be a support for the operator to determine the endpoint of root surface instrumentation.

Tannenbaum and metal stents in the palliative treatment of malignant distal bile duct obstruction: a comparative study of patency and cost effectiveness.

BACKGROUND: Stent clogging is the major limitation of palliative treatment for malignant biliary obstruction. Metal stents have much better patency than plastic stents, but are more expensive. Preliminary data suggest that the recently designed plastic (Tannenbaum) stent has better duration of patency than the polyethylene stent. This study aimed to compare the efficacy and cost effectiveness between the Tannenbaum stent without side holes and the uncovered metal stent for patients with malignant distal common bile duct obstruction. METHODS: In this study, 47 patients (median age, 73 years, range, 56-86 years) with inoperable malignant distal common bile duct strictures were prospectively randomized to receive either a Tannenbaum stent (n = 24) or an uncovered self-expandable metal stent (n = 23). The patients were clinically evaluated, and biochemical tests were analyzed if necessary until their death or surgery for gastric outlet obstruction. Cumulative first stent patency and patient survival were compared between the two groups. Cost-effectiveness analysis also was performed for the two study groups. RESULTS: The two groups were comparable in terms of age, gender, and diagnosis. The median first stent patency was longer in the metal group than in the Tannenbaum stent group (255 vs 123.5 days; p = 0.002). There was no significant difference in survival between the two groups. The total cost associated with the Tannenbaum stents was lower than for the metal stents (17,700 vs 30,100 euros; p = 0.001), especially for patients with liver metastases (3,000 vs 6,900 euros; p < 0.001). CONCLUSIONS: Metal stent placement is an effective treatment for inoperable malignant distal common bile duct obstruction, but Tannenbaum stent placement is a cost-saving strategy, as compared with metal stent placement, especially for patients with liver metastases and expected short survival time.