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Background and Objective Previous studies in laser assisted vascular welding have been limited by the lack of a reliable end point for tissue fusion. As a means of improving the reproductibility of laser assisted repairs, a system incorporating real time temperature monitoring and closed loop feedback was used. Study Design/Materials and Methods The system consisted of a direct view infrared thermometer for monitoring the laser heated spot, a 1.9 μm diode laser, and a microprocessor for data acquisition and feedback control of the laser power to maintain a constant tissue temperature. Rat aortas were welded under constant surface temperature conditions. Results In vivo temperature stability of ±2°C was achieved over a temperature range of 70–90°C pertinent to welding small vessels. When welds were completed using the feedback system to maintain the tissue temperature at 80°C, the acute success rate was 100% and the burst pressure was 290 ± 70 mmHg. Conclusion These studies demonstrate that the use of real time monitoring and feedback control results in improved consistency for vascular tissue welding. © 1996 Wiley‐Liss, Inc.

Elevated temperature, normally a characteristic of inflammation, is a potential indicator of periodontal disease. Conversely, local periodontal site temperatures within normal variation could suggest relative periodontal health. To evaluate this potential, a temperature probe was designed with rapid response (< 1 s), high accuracy and reproducibility ( + 0.1°C), good transducer thermal isolation and physical dimensions approximating those of a conventional periodontal probe. To compensate for subject-to-subject variations in core temperature, site temperatures were measured and expressed as differences relative to the sublingual temperature. A cross sectional study was conducted using this instrument in which pocket temperatures of 14 subjects with advanced adult periodontitis were measured and compared with the sulcus temperatures of 11 healthy subjects. Overall, the mean site temperature of the diseased subjects was 0.65 °C higher than that of the healthy subjects. A natural posterior-to-anterior temperature gradient was observed with the posterior sites being hotter than the anterior sites. Tooth-by-tooth analysis showed that diseased teeth have higher temperatures than anatomically equivalent healthy teeth (p

Elevated temperature, normally a characteristic of inflammation, is a potential indicator of periodontal disease. Conversely, local periodontal site temperatures within normal variation could suggest relative periodontal health. To evaluate this potential, a temperature probe was designed with rapid response (less than 1 s), high accuracy and reproducibility (+/- 0.1 degree C), good transducer thermal isolation and physical dimensions approximating those of a conventional periodontal probe. To compensate for subject-to-subject variations in core temperature, site temperatures were measured and expressed as differences relative to the sublingual temperature. A cross sectional study was conducted using this instrument in which pocket temperatures of 14 subjects with advanced adult periodontitis were measured and compared with the sulcus temperatures of 11 healthy subjects. Overall, the mean site temperature of the diseased subjects was 0.65 degree C higher than that of the healthy subjects. A natural posterior-to-anterior temperature gradient was observed with the posterior sites being hotter than the anterior sites. Tooth-by-tooth analysis showed that diseased teeth have higher temperatures than anatomically equivalent healthy teeth (p less than 0.01). Threshold temperatures for differentiating diseased and healthy teeth were determined to optimize sensitivity and specificity. The results suggest that site temperature is a diagnostic of inflammatory activity associated with periodontal disease. The specifically designed instrument detected significant disease-related departures from normality.

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