SWIR Imaging of Lesions on Tooth Surfaces

2021 ◽  
Author(s):  
Daniel Fried
Keyword(s):  
Tooth Surfaces

The Use of High - Sucrose Culture Media for the Identification of Oral Streptococci in Infant- Mother Pairs

2017 ◽  
Vol 68 (11) ◽  
pp. 2691-2693
Author(s):  
Krisztina Martha ◽  
Cristina Bica ◽  
Edva Anna Frunda
Keyword(s):  
Culture Media ◽  
Bacterial Flora ◽  
Mutans Streptococci ◽  
Resistant Bacteria ◽  
Oral Streptococci ◽  
Streptococcus Sobrinus ◽  
Sugar Intake ◽  
Tooth Surfaces ◽  
Refined Carbohydrates ◽  
High Sucrose

By the end of the 60�s, the theory that refined carbohydrates promotes the absorption of saccharolytic Gram-positive microbial species on the tooth surfaces has become generally. Mutans streptococci (Streptococcus mutans and Streptococcus sobrinus) were key players in this theory. On agar plates, Str. mutans produces small, circular colonies, in the presence of glucose, and in the presence of sucrose large, sticky, gelatinous colonies. This gelatinous texture is due to the shell material: mutant 1 � 3 glucose polymers and dextran 1 �! 6 glucose polymers. Str. mutans are able to survive in the oral cavity with a pH lower than 5.5. That is why consecutive multiple sugar intake promotes the colonization of Str. mutans, which results in dental caries in stagnant zones. As oral pH is continuously shifted to acid, more acid-resistant bacteria appear. Our aim was to identify species in infant-mother pair gingival crevicular bacterial flora, which can be detected on high-sucrose culture media and to underline the jeopardy of vertical oral contamination from mother to infant.

scholarly journals Is the number of procedures completed a valid indicator of final year student competency in operative dentistry?

BDJ ◽  
2021 ◽  
Vol 230 (10) ◽  
pp. 663-670
Author(s):  
Luke J. Dawson ◽  
Kathryn Fox ◽  
Mark Jellicoe ◽  
Elliot Adderton ◽  
Vince Bissell ◽  
...  
Keyword(s):  
Valid Measure ◽  
Operative Dentistry ◽  
Student Activity ◽  
Frequent Type ◽  
Student Cohorts ◽  
Tooth Surfaces

AbstractIntroduction Concerns regarding the preparedness of dental graduates often focus on the number of procedures undertaken before qualification.Aims To assess the validity of numerical requirements in determining whether a student has sufficient competency to graduate.Materials and methods In total, 50,821 observations of student activity while on the restorative clinic, for two integrated student cohorts (n = 139), were continuously recorded using the LiftUpp system from their third year to graduation. Analysis of data determined the most frequent type, location and difficulty of the direct restorations provided.Results Four groups of students, categorised by the total number of restorations they provided, were identified. Those with the most restorations (70+) had a statistically significantly greater experience in restoring different tooth surfaces, in different quadrants, on different patients than those with the least (40-49). However, increased numbers did not correlate with increasing difficulty, suggesting that students simply became more adept at easier procedures.Discussion Using a derived measure of 'consistency', it was observed that increased performance consistency was not correlated with greater overall experience. Furthermore, only 4% of students were 100% consistent in their performance in their final year.Conclusions These data suggest that a 'numerical requirements' approach cannot be used, in isolation, as a valid measure of the competency of an individual. Further work is needed to validate consistency as a holistic measurement to characterise the performance of graduates.

Effect of Sustained Interventions from Infancy to Toddlerhood in Children with Cleft Lip and Palate for Preventing Early Childhood Caries

2021 ◽  
pp. 1-9
Author(s):  
Sivasubramanian Abirami ◽  
Noopur Panchanadikar ◽  
Murugan Satta Muthu ◽  
Suganya Balasubramanian ◽  
Jyotsna Murthy ◽  
...  
Keyword(s):  
Early Childhood ◽  
Early Childhood Caries ◽  
Cleft Lip ◽  
Cleft Lip And Palate ◽  
Intervention Group ◽  
Primary Caregivers ◽  
Assessment System ◽  
Incidence Density ◽  
Tooth Surfaces ◽  
Childhood Caries

The study aimed to evaluate the effectiveness of sustained interventions in children with cleft lip and palate (CLP) for preventing early childhood caries (ECC). This prospective, nonrandomized interventional cohort study was conducted in infants aged 0–12 months with congenital CLP. Interventions were given to parents/primary caregivers in the form of combined oral health-care measures (sterile wet gauze piece, finger brush, toothbrush, and toothpaste) by a motivational interviewing approach. Education of primary caregivers on oral hygiene was provided by audiovisual aids and demonstration. Reinforcement of the prescribed regimen was done through daily short message services in caregivers’ preferred language and bimonthly telephone calls. Participants were followed up for 9–32 months from the time of recruitment, with a mean period of 18.3 ± 5.1 months. Rates of dental caries were represented as prevalence rates, incidence density, and transitional probability. The distribution of the International Caries Detection and Assessment System (ICDAS) scores on different tooth surfaces affected in the intervention group was compared descriptively with that of the age- and sex-matched historical control groups. On analysis of surface-wise distribution of the ICDAS scores in the intervention group (<i>n</i> = 1,919), 1.2% (<i>n</i> = 24) had noncavitated lesions (ICDAS codes 1 and 2), 0.88% (<i>n</i> = 17) had cavitated lesions (ICDAS codes 3–6), and 0.26% (<i>n</i> = 5) had both cavitated and noncavitated lesions (ICDAS codes 1–6). The incidence density of caries-affected children observed at the first and last follow-ups was 1.2 persons/100 person-months and 1.3 persons/100 person-months of observation, respectively. The incidence density of new caries-affected tooth surfaces at the first and last follow-ups was 0.163 surfaces/100 surface-months and 0.062 surfaces/100 surface-months, respectively. Maxillary first molars had the maximum transition from sound to the cavitated lesion (11.5%), followed by maxillary incisors from sound to noncavitated (7.5%) at the last follow-up. Based on the newly developed assessment criteria in our study, sustained interventions proved to be significantly effective in preventing ECC in children with CLP.

A Method for in vitro Studies on Fluoride Uptake in Enamel Using Single Tooth Surfaces

1976 ◽  
Vol 10 (5) ◽  
pp. 370-378 ◽  
Author(s):  
E. Kirkegaard ◽  
I.J. Møller ◽  
Skov Jensen
Keyword(s):  
In Vitro Studies ◽  
Fluoride Uptake ◽  
Single Tooth ◽  
Tooth Surfaces

The Effect of Curcumin against In Vitro Adhesion of Implant Device-Associated Bacteria on Nanosized Titanium Dioxide

2013 ◽  
Vol 23 ◽  
pp. 83-90
Author(s):  
Seung Han Oh ◽  
In Young Na ◽  
Kyoung Hee Choi
Keyword(s):  
Titanium Dioxide ◽  
Bacterial Adhesion ◽  
Curcuma Longa ◽  
Human Tooth ◽  
Bacterial Strains ◽  
Associated Bacteria ◽  
Tooth Surfaces ◽  
Titanium Surfaces ◽  
Main Component

Although titanium dioxide (TiO2) is an implantable biomaterial with its antibacterial activity, infection on TiO2 surfaces remains a problem for medical settings. According to our previous studies, curcumin, the main component of turmeric (Curcuma longa), partially hindered the attachment of Streptococcus mutans to human tooth surfaces. Therefore, it was examined whether several implant device-associated bacteria were able to adhere to nanosized TiO2 surfaces. In addition, the effect of curcumin on the bacterial adhesion was investigated. Bacterial strains were cultured on pure Ti and TiO2 surfaces with various nanotube sizes in the absence or presence of curcumin and observed by scanning electron microscopy. Consequently, most bacteria adhered to Ti and TiO2 surfaces. However, curcumin increased the adhesion of bacteria including S. mutans. The results suggest that bacterial adhesion to implant titanium surfaces can be augmented via curcumin ingestion.

scholarly journals Computerized Design and Generation of Low-Noise Helical Gears with Modified Surface Topology

1995 ◽  
Vol 117 (2A) ◽  
pp. 254-261 ◽  
Author(s):  
F. L. Litvin ◽  
N. X. Chen ◽  
J. Lu ◽  
R. F. Handschuh
Keyword(s):  
Gear Tooth ◽  
Error Function ◽  
Transmission Error ◽  
Low Noise ◽  
Surface Topology ◽  
Helical Gears ◽  
Transmission Errors ◽  
Bearing Contact ◽  
Pinion Gear ◽  
Tooth Surfaces

An approach for the design and generation of low-noise helical gears with localized bearing contact is proposed. The approach is applied to double circular arc helical gears and modified involute helical gears. The reduction of noise and vibration is achieved by application of a predesigned parabolic function of transmission errors that is able to absorb a discontinuous linear function of transmission errors caused by misalignment. The localization of the bearing contact is achieved by the mismatch of pinion-gear tooth surfaces. Computerized simulation of meshing and contact of the designed gears demonstrated that the proposed approach will produce a pair of gears that has a parabolic transmission error function even when misalignment is present. Numerical examples for illustration of the developed approach are given.

Deformations and Stresses in Face-Hobbed Spiral Bevel Gears

2011 ◽  
Author(s):  
Vilmos V. Simon
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Nodal Point ◽  
Design Parameters ◽  
Element Discretization ◽  
Spiral Bevel Gears ◽  
Bevel Gears ◽  
Tooth Surfaces ◽  
Spiral Bevel ◽  
Element Method

In this study an attempt is made to predict displacements and stresses in face-hobbed spiral bevel gears by using the finite element method. A displacement type finite element method is applied with curved, 20-node isoparametric elements. A method is developed for the automatic finite element discretization of the pinion and the gear. The full theory of the generation of tooth surfaces of face-hobbed spiral bevel gears is applied to determine the nodal point coordinates on tooth surfaces. The boundary conditions for the pinion and the gear are set automatically as well. A computer program was developed to implement the formulation provided above. By using this program the influence of design parameters and load position on tooth deflections and fillet stresses is investigated. On the basis of the results, obtained by performing a big number of computer runs, by using regression analysis and interpolation functions, equations for the calculation of tooth deflections and fillet stresses are derived.

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