Comparative Study of the Restoration Quality in Cavities prepared with Er:YAG Laser in Quantum Square Pulse Mode and Conventional Method

2016 ◽  
Vol 6 (1) ◽  
pp. 31-37 ◽  
Author(s):  
Antonis Kallis ◽  
Kosmas Tolidis ◽  
Paris Gerasimou ◽  
Nor Gutknecht ◽  
Eugenia Koliniotou-Koumpia
Keyword(s):  
Comparative Study ◽  
Conventional Method ◽  
Dental Treatment ◽  
Er:Yag Laser ◽  
Short Pulse ◽  
Pulse Mode ◽  
Smear Layer ◽  
Small Scale ◽  
Dentinal Tubules ◽  
Treatment Parameter

ABSTRACT Nowadays, dental treatment has been enriched by the use of lasers. The introduction of the novel treatment parameter of quantum square pulse (QSP) constitutes an additional challenge to older techniques, promising minimally invasive treatments. The aim of this study is to comparatively investigate the quality of cavity preparations using erbium-doped yttrium-aluminum-garnet (Er:YAG) laser with QSP technology as opposed to the conventional bur. The Er:YAG laser (2940 nm) has been used at 120 mJ energy level in QSP and medium short pulse (125 μs) modes. Subsequently, the dentin and enamel surfaces were examined using scanning electron microscopy techniques and compared with cuttings prepared with conventional bur. The laser-treated dentin samples exhibited relatively homogenous surfaces without smear layer and with open dentinal tubules. Laser-treated enamel showed scaly surfaces but again free of smear layer. In contrast, both dentin and enamel samples treated with the conventional bur showed abundance of smear layer, groove marks, small-scale cracks, and closed dentinal tubules. How to cite this article Kallis A, Tolidis K, Gerasimou P, Gutknecht N, Koliniotou-Koumpia E. Comparative Study of the Restoration Quality in Cavities prepared with Er:YAG Laser in Quantum Square Pulse Mode and Conventional Method. Int J Laser Dent 2016;6(1):31-37.

scholarly journals Effects of Er:YAG Laser on Mineral Content of Sound Dentin in Primary Teeth

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Cigdem Guler ◽  
Meral Arslan Malkoc ◽  
Veli Alper Gorgen ◽  
Erhan Dilber ◽  
Mehmet Bulbul
Keyword(s):  
Surface Roughness ◽  
Mineral Content ◽  
Primary Teeth ◽  
Er:Yag Laser ◽  
Short Pulse ◽  
Pulse Mode ◽  
Emission Spectrometry ◽  
Control Group ◽  
Group A ◽  
Group B

The aim of the present study was to evaluate the mineral content of sound dentin in primary teeth prepared using an Er:YAG laser at two different power settings. Thirty-six primary second molars were used in this study. Three dentin slabs were obtained from each tooth, and the slabs were randomly divided into three groups: Group A, control; Group B, Er:YAG laser at 3.5 W, 175 mJ, and 20 Hz, short pulse mode; and Group C, Er:YAG laser at 4 W, 200 mJ, and 20 Hz, medium-short pulse mode. One dentin slab per group was used to evaluate the dentinal morphology and surface roughness values using SEM and profilometer, respectively. Mineral content in the dentin slabs were calculated by inductively coupled plasma-atomic emission spectrometry (ICP-AES). The data were analyzed by one-way analysis of variance and Tukey’s HSD tests. No significant differences in Ca, K, Mg, Na, and P levels or Ca/P ratio were found among the groups(P>0.05). SEM micrographs showed that surface irregularities increased with a higher power setting. The surface roughness after laser treatment in Group B and Group C was found to be similar, unlike Group A.

scholarly journals SEM Evaluation of Tooth Surface after a Composite Filling Removal Using Er:YAG Laser, Drills with and without Curettes, and Optional EDTA or NaOCl Conditioning

Materials ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4469
Author(s):  
Jan Kiryk ◽  
Jacek Matys ◽  
Kinga Grzech-Leśniak ◽  
Marzena Dominiak ◽  
Małgorzata Małecka ◽  
...  
Keyword(s):  
Surface Structure ◽  
Sodium Hypochlorite ◽  
Er:Yag Laser ◽  
Mechanical Damage ◽  
Smear Layer ◽  
Tooth Surface ◽  
Dentinal Tubules ◽  
Sem Image ◽  
Diamond Drill ◽  
Tooth Surfaces

(1) Background: This study aimed to evaluate the microporosity of the tooth surface structure adjacent to the cemento-enamel junction (CEJ) after the removal of composite fillings with a drill in comparison with removal by an Er:YAG laser and after cleaning with a periodontal curette, chemical EDTA and NaOCl (sodium hypochlorite) conditioning. (2) Methods: The research material consisted of 30 extracted premolars with cervical composite fillings. The teeth were divided into six groups according to the method of tooth preparation: group G1 (n = 5)—a diamond drill; group G2 (n = 5)—a diamond drill + curette; group G3 (n = 5)—a diamond drill + 24% EDTA (PrefGel, Straumann, Switzerland); group G4 (n = 5)—an Er:YAG laser (LightWalker, Fotona, Ljubljana, Slovenia) set with the following parameters: power: 1.65 W (composite removal, CR), 1.2 (tooth conditioning, TC), energy: 110 mJ (CR), 80 mJ (TC), frequency: 15 Hz, pulse duration: 50 μs, tip diameter: 1 mm, air/fluid cooling: 4, distance 1.5 mm, energy density: 14.01 J/cm2 (CR), 10.19 J/cm2 (TC); group G5 (n = 5)—an Er:YAG laser + 2% sodium hypochlorite (NaOCl); group G6 (n = 5)—an Er:YAG laser + 5.25% NaOCl. In each tooth, three cavities were made and subjected to analysis. The dentin surface was evaluated using a scanning electron microscope (SEM). (3) Results: Groups G1 and G2 exhibited mechanical damage to the tooth surface structure caused by the rotary motion of a diamond drill. The SEM image showed a smear layer that could only be removed chemically using 24% EDTA gel (group G3). The tooth surfaces prepared with the Er:YAG laser (groups G4–G6) revealed a homogeneous structure without damage along with open dentinal tubules (without smear layer) and visible denaturation of collagen fibers. The sodium hypochlorite (NaOCl) conditioning did not increase the visibility of dentinal tubules. (4) Conclusions: Dentin surfaces have open dentinal tubules after removal of the composite filling using the Er:YAG laser and therefore do not require additional NaOCl conditioning.

scholarly journals Mind the gap – Part 1: Accurately locating warm marine boundary layer clouds and precipitation using spaceborne radars

2020 ◽  
Vol 13 (5) ◽  
pp. 2363-2379 ◽  
Author(s):  
Katia Lamer ◽  
Pavlos Kollias ◽  
Alessandro Battaglia ◽  
Simon Preval
Keyword(s):  
Boundary Layer ◽  
Cloud Cover ◽  
Marine Boundary Layer ◽  
Short Pulse ◽  
Pulse Mode ◽  
Cloud Base ◽  
Boundary Layer Clouds ◽  
Highly Sensitive ◽  
Eastern North Atlantic ◽  
Long Pulse

Abstract. Ground-based radar observations show that, over the eastern North Atlantic, 50 % of warm marine boundary layer (WMBL) hydrometeors occur below 1.2 km and have reflectivities of < −17 dBZ, thus making their detection from space susceptible to the extent of surface clutter and radar sensitivity. Surface clutter limits the ability of the CloudSat cloud profiling radar (CPR) to observe the true cloud base in ∼52 % of the cloudy columns it detects and true virga base in ∼80 %, meaning the CloudSat CPR often provides an incomplete view of even the clouds it does detect. Using forward simulations, we determine that a 250 m resolution radar would most accurately capture the boundaries of WMBL clouds and precipitation; that being said, because of sensitivity limitations, such a radar would suffer from cloud cover biases similar to those of the CloudSat CPR. Observations and forward simulations indicate that the CloudSat CPR fails to detect 29 %–43 % of the cloudy columns detected by ground-based sensors. Out of all configurations tested, the 7 dB more sensitive EarthCARE CPR performs best (only missing 9.0 % of cloudy columns) indicating that improving radar sensitivity is more important than decreasing the vertical extent of surface clutter for measuring cloud cover. However, because 50 % of WMBL systems are thinner than 400 m, they tend to be artificially stretched by long sensitive radar pulses, hence the EarthCARE CPR overestimation of cloud top height and hydrometeor fraction. Thus, it is recommended that the next generation of space-borne radars targeting WMBL science should operate interlaced pulse modes including both a highly sensitive long-pulse mode and a less sensitive but clutter-limiting short-pulse mode.

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