scholarly journals Effect of 940 nm Gallium Arsenide Laser on dental hard tissues temperature propagation

2015 ◽  
Vol 18 (4) ◽  
pp. 104
Author(s):  
Javier Higuera ◽  
Ariel Denis Espinoza ◽  
Sebastian Contreras Marino

<p align="left"><span style="color: #212121;"><span><span>Despite the extensive literature available on laser at the present, there are few articles about the temperature of laser radiation and its propagation on dental hard tissues. The present study general objective is to evaluate </span></span></span><span style="color: #212121;"><span><span><em>in vitro</em></span></span></span><span style="color: #212121;"><span><span><span> the effect of temperature increase produced by the laser radiation of 940 nm on the dental hard tissues and, as specific objectives a) analyze current parameters using 940 nm laser on dental hard tissues b) assess the most appropriate criteria for this wavelength on dental hard tissues. 4 groups of 5 teeth each (lower incisors, upper incisors, canines and molars) were irradiated with 6 powers and frequencies (0.1 to 0.4W, in continuous or pulsed mode). The results of this study allow us to ensure that, in the chosen parameters, major powers, but delivered in pulsed manner, generate less temperature rise. Extremely significant differences were found between groups of lower incisors and molars. 0.1W power, pulsed mode for 20 msec, with 20 millisecond intervals, generated less than 4 Celsius degrees of temperature increase in all the cases studied. In conclusion, the use of powers of up to 0.4W, in pulsed mode, generated thermal effects of less than 4 Celsius degrees.</span></span></span></span></p>

2011 ◽  
Vol 36 (5) ◽  
pp. 529-536 ◽  
Author(s):  
FY Cakir ◽  
Y Korkmaz ◽  
E Firat ◽  
SS Oztas ◽  
S Gurgan

SUMMARY Purpose To determine the change in the chemical composition of enamel and dentin as well as to evaluate the differences in surface texture of the same dental hard tissues following three at-home bleaching systems in vitro. Methods Sixty extracted intact human anterior teeth were used in this study. Thirty teeth were used as samples for enamel, and the buccal surfaces of the remaining 30 teeth were abraded and used as dentin samples. Prior to bleaching treatments, calcium (Ca), phosphorus (P), potassium (K), sodium (Na), magnesium (Mg), fluoride (F), and oxygen (O) levels of each sample were measured using an energy dispersive spectrometer. The teeth were then randomly allocated into three groups according to the bleaching system used, as follows: GI, 10% carbamide peroxide (CP); GII, 20% CP; GIII, and 35% CP. Following the bleaching treatments, Ca, P, K, Na, Mg, F, and O measurements were repeated. The surface configurations were examined using scanning electron microscopy (SEM). The data were analyzed using Wilcoxon signed rank and Kruskal-Wallis tests followed by the Dunn test. Results All three bleaching systems tested caused similar changes in the chemical composition of enamel and dentin. Bleaching systems decreased Ca and K, while F and O levels increased in enamel. In dentin, Ca, P, and K levels decreased; however, Na, F, and O levels increased. SEM observations revealed no deleterious effect on enamel and dentin. Conclusion The use of home bleaching agents could affect the chemical composition of dental hard tissues, whereas the change in the chemical composition of enamel and dentin was not affected by the CP concentration of the bleaching systems used.


1996 ◽  
Author(s):  
David C. Attrill ◽  
Simon R. Farrar ◽  
A. S. Blinkhorn ◽  
R. M. Davies ◽  
Mark R. Dickinson ◽  
...  

2018 ◽  
Vol 69 (6) ◽  
pp. 1574-1577
Author(s):  
Monica Monea ◽  
Daniela Esian ◽  
Reka Soos ◽  
Adrian Tohati ◽  
Alexandru Sitaru ◽  
...  

Lasers can interact with dental tissues inducing changes in tooth characteristics, regarding the surface morphology and elemental composition. The alterations were observed in Calcium, Phosphorus, Sodium, Oxygen and Carbon elements, which influence the resistance and chemical properties of dental hard tissues. The thermal energy used by laser reduces water content of the tissues and as a consequence, the level of oxygen composition decreases after irradiation. Numerous studies had demonstrated its ability to ablate hard-tissues, without any detrimental thermal effects such as cracking or melting for the adjacent tissues. The aim of this article is to present the in vitro effects of Er:YAG laser in comparison with sonic, ultrasonic and manual instruments on the root cement during scaling and root planning, evaluated by scanning electron microscope. The study was conducted on extracted teeth, divided in four groups according to the method used for scaling and root planning. The specimens were analyzed by scanning electron microscopy and the morphological alterations of the cement were evaluated based on a scoring system. Data were statistically analyzed using Mann-Whitney test and the level of significance was set at p[0.05.We noted unfavorable results on the root cement after using Er:YAG laser as craters and cracks induced by heat. There was a greater amount of roughness on the root surface after Er:YAG was used for scaling and root planning compared to manual, sonic and ultrasonic methods. Despite favorable results obtained after the use of Er:YAG laser during periodontal treatment, further clinical studies are necessary in order to determine in which moment of the therapy these methods are most suitable.


1993 ◽  
Author(s):  
Harvey A. Wigdor ◽  
Joseph T. Walsh, Jr. ◽  
Steven R. Visuri

2000 ◽  
Vol 28 (4) ◽  
pp. 265-270 ◽  
Author(s):  
M.L Hunter ◽  
N.X West ◽  
J.A Hughes ◽  
R.G Newcombe ◽  
M Addy

2010 ◽  
Vol 38 (3) ◽  
pp. 182-190 ◽  
Author(s):  
J. Field ◽  
P. Waterhouse ◽  
M. German

1990 ◽  
Vol 80 (3) ◽  
pp. 431-436 ◽  
Author(s):  
Isabelle Delvallee ◽  
Annie Paffen ◽  
Geert-Jan De Klerk

1973 ◽  
Vol 29 (01) ◽  
pp. 183-189
Author(s):  
C. A Praga ◽  
E. M Pogliani

SummaryTemperature represents a very important variable in ADP-induced platelet aggregation.When low doses of ADP ( < 1 (μM) are used to induce platelet aggregation, the length of the incubation period of PRP in the cuvette holder of the aggregometer, thermostatted at 37° C, is very critical. Samples of the same PRP previously kept at room temperature, were incubated for increasing periods of time in the cuvette of the aggregometer before adding ADP, and a significant decrease of aggregation, proportional to the length of incubation, was observed. Stirring of the PRP during the incubation period made these changes more evident.To measure the exact temperature of the PRP during incubation in the aggre- gometer, a thermocouple device was used. While the temperature of the cuvette holder was stable at 37° C, the PRP temperature itself increased exponentially, taking about ten minutes from the beginning of the incubation to reach the value of 37° C. The above results have a practical significance in the reproducibility of the platelet aggregation test in vitro and acquire particular value when the effect of inhibitors of ADP induced platelet aggregation is studied.Experiments carried out with three anti-aggregating agents (acetyl salicyclic acid, dipyridamole and metergoline) have shown that the incubation conditions which influence both the effect of the drugs on platelets and the ADP breakdown in plasma must be strictly controlled.


Sign in / Sign up

Export Citation Format

Share Document