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.

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 The Microflora Diversity and Profiles in Dental Plaque Biofilms on Brackets and Tooth Surfaces of Orthodontic Patients

2019 ◽  
Vol 53 (3) ◽  
pp. 183-188
Author(s):  
Kabilan Velliyagounder ◽  
Anil Ardeshna ◽  
Julia Koo ◽  
Mathew Rhee ◽  
Daniel H. Fine
Keyword(s):  
Agar Plate ◽  
Bacterial Biofilm ◽  
Blood Agar Plate ◽  
Tooth Surface ◽  
Pcr Analysis ◽  
Orthodontic Appliances ◽  
Time Points ◽  
Fixed Orthodontic Appliances ◽  
Plaque Ph ◽  
Tooth Surfaces

Objective: Fixed orthodontic appliances may influence the oral environment through accumulation of plaque, decreased plaque pH, and increased gingival inflammation. These changes in the oral cavity can potentially lead to periodontal disease, demineralization, and other infectious diseases. Materials and Methods: To investigate the changes in biofilm throughout the initial 2 weeks, we placed a stainless steel bracket on the upper second premolar and collected plaque samples on the bracket and on the tooth surface at different time points (0, 24, 48 h and 1 and 2 weeks) and plated on tryptic soy agar blood agar plate, and kept at 37°C in an anaerobic chamber for 5 days to determine the CFUs of bacteria. At the end of 2 weeks, we removed the bracket and elastomeric module, and we isolated genomic DNA from the bacterial biofilm for identification of bacteria by 16S rRNA PCR analysis. We also analyzed the morphology of biofilm on the bracket by scanning electron microscope. Results: Our results show that the bacterial biofilm was significantly increased on the bracket in all the subjects, whereas on the tooth surface, the CFUs were not significantly increased. PCR assay showed that biofilm on orthodontic brackets from all subjects showed colonization by Streptococcus gordonii, Porphyromonas gingivalis and Streptococcus mutans were observed on some of the subjects after 48 h, whereas Aggregatibacter actinomycetemcomitans biofilm was observed in all the time points except 24 h. Conclusion: This study demonstrated that both periodontal and cariogenic bacterial biofilms were formed on the bracket as early as 24 h.

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 Scanning electron microscopic examination of enamel surface after fixed orthodontic treatment: In-vivo study

2012 ◽  
Vol 140 (1-2) ◽  
pp. 22-28 ◽  
Author(s):  
Tijana Sessa ◽  
Jelena Civovic ◽  
Tina Pajevic ◽  
Jovana Juloski ◽  
Milos Beloica ◽  
...  
Keyword(s):  
Electron Microscopic Examination ◽  
Surface Damage ◽  
Multivariate Regression Analysis ◽  
Enamel Surface ◽  
Orthodontic Appliances ◽  
Electron Microscopic ◽  
Fixed Orthodontic Appliances ◽  
Tooth Surfaces ◽  
Scanning Electron

Introduction. Therapy with fixed orthodontic appliances starts with bracket bonding and ends with debonding of brackets, leaving enamel surface varied. Objective. The aim of this pilot study was to examine enamel surface before and after debonding of orthodontic brackets by the use of scanning electron microscopy (SEM). Methods. Epoxy replicas of four patients? premolars indicated for therapy with fixed orthodontic appliances were made and brackets were bonded to their teeth with a different adhesives (Enlight, No-mix, Fuji Ortho LC and Heliosit Orthodontic) (n=4). Two months later, brackets on premolars were debonded and amounts of adhesive left on the tooth surfaces and the bracket bases were evaluated with the adhesive remnant index (ARI). After resin removal, epoxy replicas were made and the surface of premolars was evaluated with the enamel surface index (ESI). All replicas of premolars (n=32) were prepared for SEM examination and compared under different magnifications. Tooth damage was estimated based on correlation between ARItooth and ESI. Results. Pearson?s ?2 test showed no significant differences between ARItooth and ARIbracket of four materials used. Nonparametric correlations showed significant differences between ARItooth and ARIbracket, ESI and ARItooth, and between ESI and ARIbracket. Increasing of ARItooth is followed with the descent of ARIbracket and the ascent of ESI. Multivariate regression analysis showed a significant correlation between ESI and ARItooth. Conclusion. Most bond failures took place at enamel-adhesive interface. ARItooth was a predictor to enamel surface damage. The type of material did not affect enamel surface damage.

Silica Nanoparticles to Polish Tooth Surfaces for Caries Prevention

2008 ◽  
Vol 87 (10) ◽  
pp. 980-983 ◽  
Author(s):  
R.M. Gaikwad ◽  
I. Sokolov
Keyword(s):  
Silica Nanoparticles ◽  
Ex Vivo ◽  
Bacterial Attachment ◽  
Nanometer Scale ◽  
Human Teeth ◽  
Cariogenic Bacteria ◽  
Force Microscopy ◽  
Atomic Force ◽  
Tooth Surfaces ◽  
Scale Roughness

Although silica particles have been used for tooth polishing, polishing with nanosized particles has not been reported. Here we hypothesize that such polishing may protect tooth surfaces against the damage caused by cariogenic bacteria, because the bacteria can be easily removed from such polished surfaces. This was tested on human teeth ex vivo. The roughness of the polished surfaces was measured with atomic force microscopy (AFM). A considerably lower nanometer-scale roughness was obtained when silica nanoparticles were used to polish the tooth surfaces, as compared with conventional polishing pastes. Bacterial attachment to the dental surfaces was studied for Streptococcus mutans, the most abundant cariogenic bacteria. We demonstrated that it is easier to remove bacteria from areas polished with silica nanoparticles. The results demonstrate the advantage of using silica nanoparticles as abrasives for tooth polishing.

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.

Tool Profile Modification of Hypoid Gear Machined by Duplex Helical Method

2021 ◽  
Author(s):  
Shunxing Wu ◽  
Hongzhi Yan ◽  
Zhiyong Wang ◽  
Rengui Bi ◽  
Jia Li
Keyword(s):  
Geometric Model ◽  
Tooth Surface ◽  
Gear Pair ◽  
Hypoid Gear ◽  
Tooth Contact Analysis ◽  
Edge Contact ◽  
Profile Modification ◽  
Tool Profile ◽  
Tooth Surfaces ◽  
Loaded Tooth Contact Analysis

Abstract For the hypoid gear pair of the heavy-duty vehicle drive axle machined by the duplex helical method, in order to avoid edge contact and stress concentration on the tooth surface, a four-segment tool profile is designed to modify the concave and convex surfaces simultaneously. First, the geometric model of the four-segment tool profile is established. Second, the mathematical model of the duplex helical method based on the four-segment tool profile is established, and the method of solving the tooth surface generated by the connecting points of the four-segment tool profile is given. Finally, the finite element method of loaded tooth contact analysis is used to analyze the meshing performance of the gear pair obtained by the four-segment tool profile modification, and the results are compared with the original gear pair. The results show that after the tooth surfaces are modified, the edge contact of the tooth surfaces are avoided, the stress distribution of the tooth surfaces are improved, the maximum contact stress of the tooth surfaces are reduced, and the fatigue and wear life of the tooth surface are improved.

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