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.

Effect of Model Variables on in vitro Erosion

2015 ◽  
Vol 49 (5) ◽  
pp. 508-514 ◽  
Author(s):  
Miten Mistry ◽  
Shanshan Zhu ◽  
Rebecca Moazzez ◽  
Nora Donaldson ◽  
David W. Bartlett
Keyword(s):  
Acrylic Resin ◽  
Smear Layer ◽  
Step Height ◽  
Tooth Surface ◽  
Height Loss ◽  
Permanent Molar ◽  
Detailed Method ◽  
Tooth Surfaces ◽  
Molar Teeth

The aim of this study was to investigate the effects of tooth type (molar/premolar), tooth surface (buccal/lingual), smear layer or no smear layer, storage of specimens in deionised water, mode and speed of agitation, and rinsing method between cycles on mean step height loss and Knoop microhardness (KHN) change. Polished human enamel specimens embedded in acrylic resin were prepared from sound permanent molar and premolar tooth surfaces. A 0.3% (pH 3.2) solution of citric acid was used to erode the specimens, in a cycling procedure, consisting of 10 min immersion followed by rinsing in deionised water for 30 s with a spray bottle, for 5 cycles. The specimens were analysed with a non-contact white light profilometer and KHN. Molar teeth (148.99 ± 24.49 KHN) and buccal surfaces (155.62 ± 30.35 KHN) produced significantly less microhardness change compared to premolar (186.40 ± 20.74 KHN) and lingual surfaces (179.76 ± 23.21 KHN; p < 0001). The effect of storage and rinsing showed little difference in mean step height loss (<1 µm) and microhardness change. With no smear layer a significantly lower mean step height loss and microhardness change (p < 0.001) was observed. Agitation was performed with Orbital, Gyro and See-Saw rockers at 30, 40, 60, and 70 rpm. The mean step height loss was largest for See-Saw at 70 rpm (11.73 ± 0.91 μm) and lowest for Orbital at 30 rpm (2.76 ± 1.12 μm). A statistical difference was found between all types of agitation and speeds (p < 0.001). In conclusion, this study has shown that the variables investigated here have a significant impact on the measurable outcome, highlighting the importance of accurate and detailed method sections.

scholarly journals Laser Aided Ceramic Restoration Removal: A Comprehensive Review

2019 ◽  
Vol 10 (2) ◽  
pp. 86-91 ◽  
Author(s):  
Rezvaneh Ghazanfari ◽  
Nahal Azimi ◽  
Hanieh Nokhbatolfoghahaei ◽  
Marzieh Alikhasi
Keyword(s):  
Bond Strength ◽  
Temperature Rise ◽  
Temperature Increase ◽  
Shear Bond Strength ◽  
Er:Yag Laser ◽  
Tooth Surface ◽  
Laser Application ◽  
Conventional Procedure ◽  
Tooth Surfaces ◽  
Ceramic Restorations

Introduction: All-ceramic restorations are being widely used due to its various advantages. However, they have restricted durability and may have to be removed. The conventional procedure for removal is grinding the restoration with rotary instruments which are considered time-consuming and inconvenient. A newer advantageous method is the application of lasers for debonding ceramics from the tooth surface. The objective of this study is to provide a comprehensive literature review on laser-aided ceramic restorations debonding. Methods: We searched PubMed and Google Scholar databases. Seven articles from 2011 to 2018 were identified. Studies were assessed for the efficacy of laser application and the amount of pulpal temperature rise. Results: Studies selected were categorized according to variables including shear bond strength, debonding time and intrapulpal temperature. Oztoprak and Iseri investigated that erbium-doped yttrium, aluminum, and garnet (Er:YAG) laser application reduced shear bond strength of ceramic laminate veneers. The time of debonding took an average of 190 seconds in Rechmann’s study and 106 seconds in Morford’s study. One of the main issues while using the laser is thermal irritation of the pulp. A 5.5°C temperature increase may cause pulpal damage according to Zach and Cohen. Philips et al and Rechmann et al reported no intrapulpal harm due to temperature increase. Additionally, Phillips et al demonstrated that the laser setting affects both the debonding time and the temperature alterations and that a laser adjustment of 2.5 W/25 Hz would be the best safest group. Conclusion: Removal of ceramic crowns and veneers from tooth surfaces can be successfully done by Er:YAG laser application in a less time-consuming procedure and without any harm to the underlying dentin. However, a temperature rise in the pulp may occur which could be overcome by adequate air water cooling.

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.

Estimation of Gear Friction Coefficient using Directional Parameter of Tooth Surface

2021 ◽  
pp. 1-27
Author(s):  
Junichi Hongu ◽  
Ryohei Horita ◽  
Takao Koide
Keyword(s):  
Friction Coefficient ◽  
Contact Surface ◽  
Gear Tooth ◽  
Correction Term ◽  
Tooth Surface ◽  
Oil Film ◽  
Tooth Surfaces ◽  
Frictional Coefficients ◽  
Finishing Processes ◽  
The Relationship

Abstract This study proposes a modification of the Matsumoto equation using a directional parameter of tooth surfaces to adapt various gear finishing processes. The directional parameters of a contact surface, which affect oil film formations, have been discussed in the field of tribology; but this effect has been undetermined on the meshing gear tooth surfaces having directional machining marks. Thus, this paper investigates the relationship between the gear frictional coefficients and the directional parameters (based on ISO25178) of their tooth surfaces with the various finishing processes; and modifies the Matsumoto equation by introducing a new directional parameter to augment the various gear finishing processes. Our findings indicate that through optimizing the coefficient of the correction term the include the new directional parameter, the calculated friction values using the modified Matsumoto equation correlate more highly to the experimental friction values than that using the unmodified Matsumoto equation.

scholarly journals Exopolysaccharides Produced by Streptococcus mutans Glucosyltransferases Modulate the Establishment of Microcolonies within Multispecies Biofilms

2010 ◽  
Vol 192 (12) ◽  
pp. 3024-3032 ◽  
Author(s):  
H. Koo ◽  
J. Xiao ◽  
M. I. Klein ◽  
J. G. Jeon
Keyword(s):  
Streptococcus Mutans ◽  
Extracellular Polysaccharide ◽  
Fluorescence Labeling ◽  
Tooth Surface ◽  
Bacterial Cells ◽  
Actinomyces Naeslundii ◽  
Multispecies Biofilm ◽  
Tooth Surfaces ◽  
Glucan Synthesis

ABSTRACT Streptococcus mutans is a key contributor to the formation of the extracellular polysaccharide (EPS) matrix in dental biofilms. The exopolysaccharides, which are mostly glucans synthesized by streptococcal glucosyltransferases (Gtfs), provide binding sites that promote accumulation of microorganisms on the tooth surface and further establishment of pathogenic biofilms. This study explored (i) the role of S. mutans Gtfs in the development of the EPS matrix and microcolonies in biofilms, (ii) the influence of exopolysaccharides on formation of microcolonies, and (iii) establishment of S. mutans in a multispecies biofilm in vitro using a novel fluorescence labeling technique. Our data show that the ability of S. mutans strains defective in the gtfB gene or the gtfB and gtfC genes to form microcolonies on saliva-coated hydroxyapatite surfaces was markedly disrupted. However, deletion of both gtfB (associated with insoluble glucan synthesis) and gtfC (associated with insoluble and soluble glucan synthesis) is required for the maximum reduction in EPS matrix and biofilm formation. S. mutans grown with sucrose in the presence of Streptococcus oralis and Actinomyces naeslundii steadily formed exopolysaccharides, which allowed the initial clustering of bacterial cells and further development into highly structured microcolonies. Concomitantly, S. mutans became the major species in the mature biofilm. Neither the EPS matrix nor microcolonies were formed in the presence of glucose in the multispecies biofilm. Our data show that GtfB and GtfC are essential for establishment of the EPS matrix, but GtfB appears to be responsible for formation of microcolonies by S. mutans; these Gtf-mediated processes may enhance the competitiveness of S. mutans in the multispecies environment in biofilms on tooth surfaces.

scholarly journals Isolation of Candida species in children and their biofilm-forming ability on nano-composite surfaces

2020 ◽  
Vol 1 (1) ◽  
pp. 40-52
Author(s):  
Harina Akila Che Hussin ◽  
Nadiah Arshad ◽  
Siti Nor Humaira Nor Azemi ◽  
Raja Izzatun Nisa Raja Sahrul Hishan ◽  
Wan Nur Fatihah Wan Mohd Kamaluddin ◽  
...  
Keyword(s):  
Dental Caries ◽  
Oral Cavity ◽  
Buccal Mucosa ◽  
Candida Species ◽  
Soft Tissues ◽  
Tooth Surface ◽  
Nano Composites ◽  
Candida Spp ◽  
Nano Composite ◽  
Tooth Surfaces

Candida species including Candida albicans, Candida krusei and Candida glabrata are opportunistic microorganisms that inhabit oral cavity. The objective of this study is to determine the effect of dental caries on Candida spp. biofilm-forming ability on nano- composite with the hypothesis that dental caries enhances the colonization of Candida spp. To assess Candida spp. colonisation in the oral cavity of the paediatric patient, samples were obtained from 30 subjects aged five to six years old from Kuantan, Pahang, Malaysia. The samples were collected from buccal mucosa, palate and tooth surfaces using sterile swabs. 10 mL of patient’s saliva suspension was also collected. Following that, the samples were inoculated on CHROMagar and incubated for 24 h at 37 ºC. Candida biofilm of caries isolate C. albicans (HNFC2), and C. albicans ATCC 32354 were developed on three different types of nano-composites. The study showed that no C. albicans was isolated from the caries-free oral cavity while 76% of children with caries possessed Candida spp. 65% of the yeasts were isolated from the tooth surface. Only 35% of the total isolates were obtained from soft tissues, including palatal and buccal mucosa. C. albicans is the most isolated Candida spp. with 82% and 67% of the yeast were obtained from the tooth surface and buccal mucosa, respectively. Besides, HNFC2 significantly colonised the nano- composites more than the ATCC (P < 0.05). In the comparison of the three types of nano- composites, nano-hybrid-based containing pre-polymerised filler (cB) exhibited the least C. albicans HNFC2 cells colonisation with 7.7 x 10³ cells mL-1. In contrast, the nano-composite that contained bulk-filled nanohybrid (cC) was the most colonised with 14.3 x 10³ cells mL-1. In conclusion, dental caries enhances the colonization of Candida spp. in children's oral cavity, and that caries isolate form more biofilm on nano-composites compared to the lab strain C. albicans.

scholarly journals Minimization of Deviations of Gear Real Tooth Surfaces Determined by Coordinate Measurements

1993 ◽  
Vol 115 (4) ◽  
pp. 995-1001 ◽  
Author(s):  
F. L. Litvin ◽  
C. Kuan ◽  
J. C. Wang ◽  
R. F. Handschuh ◽  
J. Masseth ◽  
...  
Keyword(s):  
Linear Equations ◽  
Least Square Method ◽  
Least Square ◽  
Tooth Surface ◽  
Hypoid Gear ◽  
Overdetermined System ◽  
Entire Surface ◽  
First Order ◽  
Tooth Surfaces ◽  
Coordinate Measurements

The deviations of a gear’s real tooth surface from the theoretical surface are determined by coordinate measurements at the grid of the surface. A method has been developed to transform the deviations from Cartesian coordinates to those along the normal at the measurement locations. Equations are derived that relate the first order deviations with the adjustment to the manufacturing machine tool settings. The deviations of the entire surface are minimized. The minimization is achieved by application of the least-square method for an overdetermined system of linear equations. The proposed method is illustrated with a numerical example for hypoid gear and pinion.

scholarly journals Efficacy of four different irrigation techniques combined with 60°C 3% sodium hypochlorite and 17% EDTA in smear layer removal

2014 ◽  
Vol 14 (1) ◽  
Author(s):  
Xiangjun Guo ◽  
Hui Miao ◽  
Lei Li ◽  
Shasha Zhang ◽  
Dongyan Zhou ◽  
...  
Keyword(s):  
Sodium Hypochlorite ◽  
Smear Layer ◽  
Layer Removal
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