Scanning electron microscopic and energy dispersive spectrometric investigations on the effect of XeCl excimer laser on human dentin with smear layer.
The purpose of this study was to study the effect of XeCl excimer laser on smear layer covered dentine of extracted human teeth. Twenty-four freshly extracted human molar teeth were collected and randomly divided into one control group and three experimental groups of six teeth each (groups A-D). The teeth in the experimental groups were irradiated with XeCl 308-nm excimer laser at a fluence of 0.4 J cm-2 and a constant pulse repetition rate of 25 Hz. Group A was used as the control, while groups B, C and D were irradiated at different exposure times of 3, 5 and 7 s, respectively. Subsequently these teeth specimens were subjected to scanning electron microscopic (SEM) examination and energy dispersive X-ray (EDX) spectrometric analysis. The SEM examination revealed melting of the smear layer covered dentin to conceal the underlying dentinal tubules. At a longer exposure time (7 s), dentin melted to form large grains and this resulted in non-uniform closure of underlying dentinal tubules. Under the conditions of this study, it is concluded that the pulsed XeCl 308-nm excimer laser at a fluence of 0.4 J cm-2, with an exposure time of 5 s uniformly occluded exposed smear layer covered dentine with no conspicuous variation in chemical structure.
Kumar
A R Pradeep
AR
Department of Conservative Dentistry, Madras Dental College, India. arpradeeep@vsnl.com
Rao
C V Subba
CV
Parameswaran
A
A
Kishen
A
A
Lim
C S
CS
D002118:Calcium / Q000032:analysis; D002713:Chlorine; D003804:Dentin / Q000737:chemistry / Q000528:radiation effects* / Q000648:ultrastructure; D006801:Humans; D053685:Laser Therapy; D008274:Magnesium / Q000032:analysis; D008855:Microscopy, Electron, Scanning; D008963:Molar; D010758:Phosphorus / Q000032:analysis; D013052:Spectrometry, X-Ray Emission; D014978:Xenon
D010758:Phosphorus; D014978:Xenon; D002713:Chlorine; D008274:Magnesium; D002118:Calcium