Pulpotomias com laser

Abstract

O objetivo deste estudo foi avaliar o aspecto clínico das polpas dentárias submetidas a pulpotomias parciais seguidas por irradiação por laser do tipo CO₂. 66 dentes de cães foram abertos e aproximadamente 2 a 3mm da polpa coronária foi removida, sob irrigação abundante com soro fisiológico. Após a hemostasia, no grupo I, o laser CO₂ foi irradiado por 1 segundo a uma potência de 5 watts; no grupo II, 2 segundos a 3 watts; no grupo III, 2 segundos a 5 watts; no grupo IV, 1 segundo a 3 watts; no grupo V, um modo contínuo a 3 watts; no grupo VI serviu de controle, sem irradiação. Os resultados mostraram que não houve diferenças enter as potências de 3 a 5 watts. O tempo de irradiação influenciou definitivamente no aspecto clínico das polpas coronárias. Os grupos I e IV (1 segundo) causaram sangramento, que persistiu por mais de 15 minutos em todos os dentes. Os grupos II e II (2 segundos) também causaram sangramento mas este parou em aproximadamente 10 minutos. O grupo V (modo contínuo) não causou sangramento, mas houve extravasamento de plasma por quase 2 minutos. Quando comparados com o controle, todas as polpas irradiadas assumiram um aspecto gelatinoso com um tecido granular negro na superfície, cobrindo totalmente as polpas do grupo V e parcialmente os outros grupos.

The aim of this study was to evaluate the clinical aspects of dental pulps submitted to shallow pulpotomy followed by CO₂ laser irradiation at five different procedures. For this purpose, initially 66 dogs'teeth were opened and about 2 or 3 mm of coronal dental pulp was removed. Continuous irrigation with saline solution was proceeded. The teeth were randomly divided into 6 groups of 11 each. After cessation of bleeding in group I,CO2 laser (Xanar-20, USA) was irradiated for 1 second at a power of 5 watts, in group II, 2 seconds at 3watts, in group III, 2 seconds at 5 watts, in group IV, 1 second at 3 watts; in group V, a continuous mode at 3 watts; group VI served as a control, with no laser irradiation. The results showed no clinical differences between the 3W and SW powers. Time period of irradiation exposition influenced definitively to the clinical appearance of the dental pulps. Groups I and IV (1 second) were unable to stop the bleeding, which persisted over 15 minutes for all teeth. This may be due to the intense heat generated by CO₂ laser, causing vasodilation. Groups II and II (2 seconds) displayed a similar appearance, but bleeding stopped in about 10 minutes. Group V (continuous mode) had no bleeding after irradiations, but a plasma-like liquid would come out for almost 2 minutes. When comparing to the control (groupVI), all the pulps would assume a gelly-like aspect, with black granulated tissue on the surface, covering totally pulps of group V and partially the other groups. The histological results will be discussed in a further study. From the data obtained, it seems that CO₂ laser irradiation should be done in a continuous mode, for clinical convenience in terms of time taken and effective irradiation. However, further studies must be gone through before advocating this procedure in humans.