scholarly journals Surface morphology modifications of human teeth induced by a picosecond Nd:YAG laser operating at 532 nm

2009 ◽  
Vol 27 (1) ◽  
pp. 103-108 ◽  
Author(s):  
B.M. Mirdan ◽  
H.A. Jawad ◽  
D. Batani ◽  
V. Conte ◽  
T. Desai ◽  
...  
Keyword(s):  
Nd:Yag Laser ◽  
Tooth Enamel ◽  
Tooth Surface ◽  
Human Teeth ◽  
Tooth Surfaces ◽  
Sharp Edges ◽  
Short Time ◽  
Surface Morphologies ◽  
532 Nm ◽  
Conical Form

AbstractThe interaction of an Nd:YAG laser, operating at 532 nm with 40 ps pulse duration, with human teeth was studied. The results show that teeth were significantly modified at an energy fluence of about 11 J/cm2. Various surface morphologies of enamel and dentine were recorded. Features on enamel include crater (conical form) in the central part and cauliflower morphology at the periphery, whereas on dentine the crater looks like a stretched dome between sharp edges. The behavior of the enamel-dentine junction area showed different morphology with respect to both tooth enamel and dentine alone. Finally, the junction channel showed a removal of collagen fibers and the formation of a needle-like bottom structure. Generally, this investigation showed that the picosecond Nd:YAG laser can ablate a tooth surface practically instantaneously, implying that large tooth surfaces can be processed in short time.

scholarly journals Influence of different types of whitening tooth pastes on the tooth color, enamel surface roughness and enamel morphology of human teeth

F1000Research ◽  
2019 ◽  
Vol 8 ◽  
pp. 1764
Author(s):  
Mohamed Shamel ◽  
Mahmoud M. Al-Ankily ◽  
Mahmoud M. Bakr
Keyword(s):  
Surface Roughness ◽  
Tooth Enamel ◽  
Morphological Changes ◽  
Enamel Surface ◽  
Tooth Surface ◽  
Tooth Whitening ◽  
Sem Images ◽  
Human Teeth ◽  
Tooth Color ◽  
Different Types

Background: Tooth whitening usually includes the direct use of gels containing carbamide or hydrogen peroxide on the tooth enamel surface through a wide variety of products formulas. A generally new advancement in whitening of teeth uses the significant importance of the tooth color shift from yellow to blue in delivering a general enhancement in the observation of tooth whiteness. The aim of the current work was to measure the tooth whitening effects, surface roughness and enamel morphology of six different types of blue covarine-containing and blue covarine-free toothpastes using in vitro models. Methods: A total of 70 sound extracted human premolars were randomly and equally divided into seven groups, and each subjected to tooth brushing using different toothpastes. Tooth color and enamel surface roughness were measured before and after the brushing procedure using a white light interferometer, and scanning electron microscopy (SEM) was used to assess tooth surface after the procedure. Results: Toothpaste containing blue covarine resulted in the greatest improvement in tooth color amongst all groups as well as a statistically significant color difference when compared to blue covarine-free toothpaste.  Furthermore, blue covarine-containing toothpaste resulted in fewer morphological changes to the enamel surface. This was confirmed with SEM images that showed smooth enamel surfaces with fine scratches.   Conclusions: The results from the present study show that blue covarine containing toothpastes are reliable, effective in tooth whitening and produce less surface abrasion when compared to blue covarine-free toothpastes.

Thermal Stress Effects and Surface Cracking Associated With Laser Use on Human Teeth

1977 ◽  
Vol 99 (4) ◽  
pp. 189-194 ◽  
Author(s):  
R. Boehm ◽  
J. Rich ◽  
J. Webster ◽  
S. Janke
Keyword(s):  
Thermal Stress ◽  
Thermal Stresses ◽  
Tooth Enamel ◽  
Laser Energy ◽  
Surface Damage ◽  
Tooth Surface ◽  
Human Teeth ◽  
Surface Cracking ◽  
Stress Effects ◽  
Before And After

A detailed study is reported of the potential thermal stress effects and surface cracking of human teeth after absorption of laser energy. This study was motivated by the desire to define damage thresholds if lasers are used for preventive dentistry techniques. A large group of extracted teeth was exposed to manually pulsed bursts of energy of varying durations from a CW CO2 laser. The teeth were examined photographically under magnification before and after irradiation, using fluorescent dye to facilitate observation of cracks in the tooth surface. In an attempt to understand the cracking phenomena, predictions of the temperatures and thermal stresses were made. The tooth surface in the vicinity of the focused beam impingement was assumed to behave as a semi-infinite solid for the short periods of time considered. Estimated stresses where cracking occurred are compared in the paper to measured values of the ultimate strength of tooth enamel. Results are shown to be in reasonable agreement with predictions. Based on this work, a criterion is given for minimizing surface damage to the tooth.

scholarly journals Fluorescence-Aided Identification Technique (FIT) Improves Tooth Surface Clean-Up after Debonding of Buccal and Lingual Orthodontic Appliances

2021 ◽  
Vol 11 (1) ◽  
pp. 213
Author(s):  
Olivia Engeler ◽  
Oliver Stadler ◽  
Simone Horn ◽  
Christian Dettwiler ◽  
Thomas Connert ◽  
...  
Keyword(s):  
Clinical Practice ◽  
Tooth Surface ◽  
Fluorescent Light ◽  
Orthodontic Appliances ◽  
Human Teeth ◽  
Enamel Defects ◽  
Tooth Surfaces ◽  
Identification Technique ◽  
Best Fit

The aim of this study was to evaluate the use of fluorescence inducing light to aid the clean-up of tooth surfaces after bracket removal when using buccal or lingual orthodontic appliances. Two full sets of dental arches using extracted human teeth were assembled, with 14 teeth per arch. All teeth were bonded on their buccal and lingual surfaces. After debonding, a single blinded operator performed the tooth surface clean-up, as commonly performed in clinical practice; without the use of fluorescent light (non-FIT) and with two methods using fluorescent light to identify composite remnants on the tooth surfaces (FIT; OPAL and BRACE). Tooth surfaces were scanned before bonding and after clean-up, and the two scans were superimposed using the best-fit method. The results showed that the debonding method, type of tooth and type of tooth surface had a significant effect on the presence of composite remnants, enamel defects, and on debonding time. Contrary to the non-FIT method, there were no composite remnants after clean-up with the use of fluorescence inducing light. Clean-up time was significantly reduced on the buccal surfaces when using the FIT methods. On the lingual surfaces, the FIT methods resulted in larger enamel defects.

Outcomes of 532 nm Frequency-Doubled Nd:YAG Laser Use in the Treatment of Port-Wine Stains

2006 ◽  
Vol 31 (5) ◽  
pp. 509-517 ◽  
Author(s):  
Buket Pençe ◽  
Bekir Aybey ◽  
Gönül Ergenekon
Keyword(s):  
Nd:Yag Laser ◽  
Port Wine ◽  
Port Wine Stains ◽  
532 Nm

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 Comparison of 10 cm and 50 cm Long Iodine Cells in Iodine-Stabilized Diode Laser-Pumped Nd:YAG Laser at 532 nm

2018 ◽  
Vol 15 (5) ◽  
pp. 306-313
Author(s):  
Prayut Potirak ◽  
Monludee Ranusawud ◽  
Pichet Limsuwan ◽  
Prathan Buranasiri
Keyword(s):  
Diode Laser ◽  
Nd:Yag Laser ◽  
532 Nm

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.

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