Intrapulpal temperature during preparation with the Er:YAG laser compared to the conventional burr: an in vitro study.

OBJECTIVE: The authors explored whether the preparation with the Er:YAG laser showed a difference in increase of intrapulpal temperature in comparison to the conventional burr. SUMMARY BACKGROUND DATA: The effect of preparation with the Er:YAG laser on the temperature in the pulp is probably the biggest problem in using the laser for preparation of dental hard tissue. METHODS: The effect on the temperature in the pulp was studied on extracted human incisors and canines in vitro in palatinal class I cavities. The temperature during preparation with the Er:YAG laser was compared to that recorded during conventional tactile preparation with a diamond burr. The study was designed so that the pulpal cavity and the measuring probe were kept at a constant temperature of 37 degrees C from the root upward while the crown, which was thermally isolated, was exposed to preparation and cooling agents. RESULTS: During preparation with the laser, there was a temperature drop after a few seconds from 37 degrees C to 25 degrees C to 30 degrees C due to cooling with water and air. Even with trepanation, there was only an increase in temperature in the pulp when the temperature measuring probe was hit directly by the laser beam. With conventional preparation in comparison, even before trepanation there was a rise in temperature to more than 60 degrees C. CONCLUSIONS: The reduction in pain with clinical use of the Er:YAG laser for class V cavities has already been mentioned in publications and could, in addition to the nontactile preparation, be due to the lesser increase in intrapulpal temperature during the laser preparation in comparison to the conventional burr.

[Rheumatic fever, a disease undergoing change, based on the experience of the past 15 years]. / Egy megváltozott betegségröl, a reumás lázról másfél évtizedes tapasztalatok alapján.

The authors reviewed the records of paediatric patients treated at the cardiology department of the Svábhegyi Gyermekgyógyintézet during the period from 1 January 1979 to 31 December 1993. All the patients elected for the survey had rheumatic fever and represented about 20 percent of the national patient pool. Among the 62 children referred for suspected rheumatic fever 26 had carditis, and 3 suffered from pancarditis. Two children had chorea minor with carditis and there were 2 additional cases with chorea minor only. Valvular heart disease has developed in 21 patients. There were 16 patients with mitral regurgitation, these conditions have occurred in combination with mitral stenosis in 3 cases, whereas the insuffitientia of the aortic valve developed in two patients. The authors analysed the clinical signs of the patients and established that the chronic syndromes came in front. The authors have observed a favourable trend in the epidemiology of the disease, in particular, while 34 patients were referred during the first 5 years, there were only 18 cases in the second 5-years period. During the interval from 1989 to 1993, only 10 children with rheumatic fever have been referred to or treated at the authors' institute.