A Novel Evaluation Method for Detecting Defects of the Bonded Orthodontic Bracket-Tooth Interface

Background. Orthodontic patients are at high risk to develop caries. This study is introducing a clinical method detecting interfacial defects between ceramic brackets and enamel utilizing optical coherent tomography in addition to using the nanoleakage expression in vitro test. Methods. Transbond XT primer and moisture insensitive primer (MIP) were bonded to 75 human premolar enamel surfaces and divided into (XTD), (MIPD), and (MIPW) groups. The (XTD) and (MIPD) groups had ceramic brackets bonded to dry enamel surfaces using TransBond and moisture insensitive primers, respectively, while the (MIPW) samples were bonded to moist enamel using moisture insensitive primer. All specimens were examined under crosspolarization optical coherence tomography. Debonding forces of the brackets to 45 teeth (15 teeth/group). 30 bonded specimens (15 specimens/group) were cross-sectioned to detect the nanoleakage expression using scanning electron microscope equipped with energy-dispersive spectroscopy (SEM/EDS). The degree of conversion of the specimens in the experimental groups was tested using attenuated total reflectance Fourier transform infrared spectroscopy (FTIR/ATR). Results. Optical coherence tomography detected the interfacial defects between the ceramic brackets and tooth structure. One way ANOVA showed that (XTD) and (MIPD) groups recorded significantly higher bond strength values and less nanoleakage expression when compared to MIPW ( p > 0.05 ). Conclusions. Optical coherence tomography can be utilized to detect interfacial adhesive-tooth defects. Dry enamel surfaces improve the quality of the enamel/primer interface (200 words).

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A method to determine the radial compliance of porcine coronary arteries ex vivo via optical coherence tomography

Current Directions in Biomedical Engineering ◽

10.1515/cdbme-2020-3013 ◽

2020 ◽

Vol 6 (3) ◽

pp. 48-51

Author(s):

Christoph Brandt-Wunderlich ◽

Franziska Bonin ◽

Wolfram Schmidt ◽

Niels Grabow ◽

Klaus- Peter Schmitz ◽

...

Keyword(s):

Optical Coherence Tomography ◽

Coronary Arteries ◽

Vascular Tissue ◽

Ex Vivo ◽

Imaging Method ◽

In Vitro Test ◽

Optical Coherence ◽

Porcine Coronary Artery ◽

Vitro Test

AbstractOptical coherence tomography (OCT) as imaging method is widely used in ophthalmology, oncology and cardiology. For intravascular imaging the OCT is used for pre-interventional as well as post-procedural assessments. Within the current study a test setup for ex vivo determination of the compliance of porcine coronary arteries via OCT is described. Diameter measurements based on OCT imaging were performed during consecutive pressurization of a porcine coronary artery from 40 to 200 mmHg in a physiological environment. The test results indicate that the radial compliance depends on the specific segment of the artery as well as the pressure range considered. The revealed compliance data can be used for numerical simulations of the vascular tissue as well as for optimization of in vitro test setups for pulsatile testing of vascular implants.

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Dental optical coherence tomography: a comparison of two in vitro systems

Dentomaxillofacial Radiology ◽

10.1038/sj.dmfr.4600507 ◽

1999 ◽

Vol 29 (2) ◽

pp. 85-89 ◽

Cited By ~ 27

Author(s):

L L Otis ◽

B W Colston ◽

M J Everett ◽

H Nathel

Keyword(s):

Optical Coherence Tomography ◽

Optical Coherence ◽

In Vitro Systems

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Optimization of X-ray Investigations in Dentistry Using Optical Coherence Tomography

Sensors ◽

10.3390/s21134554 ◽

2021 ◽

Vol 21 (13) ◽

pp. 4554

Author(s):

Ralph-Alexandru Erdelyi ◽

Virgil-Florin Duma ◽

Cosmin Sinescu ◽

George Mihai Dobre ◽

Adrian Bradu ◽

...

Keyword(s):

Optical Coherence Tomography ◽

Radiation Dose ◽

Imaging Techniques ◽

Image Resolution ◽

Optical Coherence ◽

X Rays ◽

High Quality ◽

X Ray

The most common imaging technique for dental diagnoses and treatment monitoring is X-ray imaging, which evolved from the first intraoral radiographs to high-quality three-dimensional (3D) Cone Beam Computed Tomography (CBCT). Other imaging techniques have shown potential, such as Optical Coherence Tomography (OCT). We have recently reported on the boundaries of these two types of techniques, regarding. the dental fields where each one is more appropriate or where they should be both used. The aim of the present study is to explore the unique capabilities of the OCT technique to optimize X-ray units imaging (i.e., in terms of image resolution, radiation dose, or contrast). Two types of commercially available and widely used X-ray units are considered. To adjust their parameters, a protocol is developed to employ OCT images of dental conditions that are documented on high (i.e., less than 10 μm) resolution OCT images (both B-scans/cross sections and 3D reconstructions) but are hardly identified on the 200 to 75 μm resolution panoramic or CBCT radiographs. The optimized calibration of the X-ray unit includes choosing appropriate values for the anode voltage and current intensity of the X-ray tube, as well as the patient’s positioning, in order to reach the highest possible X-rays resolution at a radiation dose that is safe for the patient. The optimization protocol is developed in vitro on OCT images of extracted teeth and is further applied in vivo for each type of dental investigation. Optimized radiographic results are compared with un-optimized previously performed radiographs. Also, we show that OCT can permit a rigorous comparison between two (types of) X-ray units. In conclusion, high-quality dental images are possible using low radiation doses if an optimized protocol, developed using OCT, is applied for each type of dental investigation. Also, there are situations when the X-ray technology has drawbacks for dental diagnosis or treatment assessment. In such situations, OCT proves capable to provide qualitative images.

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