scholarly journals Assessment of Demineralization Inhibition Effects of Dentin Desensitizers Using Swept-Source Optical Coherence Tomography

Materials ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 1876
Author(s):  
Kumiko Matsuzaki ◽  
Yasushi Shimada ◽  
Yasuo Shinno ◽  
Serina Ono ◽  
Kozo Yamaji ◽  
...  

The purpose of this study was to evaluate the mechanism of action and the inhibiting effects of two types of desensitizers against dentin demineralization using pre-demineralized hypersensitivity tooth model in vitro. In this study, we confirmed that a hypersensitivity tooth model from our preliminary experiment could be prepared by immersing dentin discs in an acetic acid-based solution with pH 5.0 for three days. Dentin discs with three days of demineralization were prepared and applied by one of the desensitizers containing calcium fluoro-alumino-silicate glass (Nanoseal, NS) or fluoro-zinc-silicate glass (Caredyne Shield, CS), followed by an additional three days of demineralization. Dentin discs for three days of demineralization (de3) and six days of demineralization (de6) without the desensitizers were also prepared. The dentin discs after the experimental protocol were scanned using swept-source optical coherence tomography (SS-OCT) to image the cross-sectional (2D) view of the samples and evaluate the SS-OCT signal. The signal intensity profiles of SS-OCT from the region of interest of 300, 500, and 700 µm in depth were obtained to calculate the integrated signal intensity and signal attenuation coefficient. The morphological differences and remaining chemical elements of the dentin discs were also analyzed using scanning electron microscopy and energy-dispersive X-ray spectroscopy. SS-OCT images of CS and NS groups showed no obvious differences between the groups. However, SS-OCT signal profiles for both the CS and NS groups showed smaller attenuation coefficients and larger integrated signal intensities than those of the de6 group. Reactional deposits of the desensitizers even after the additional three days of demineralization were observed on the dentin surface in NS group, whereas remnants containing Zn were detected within the dentinal tubules in CS group. Consequently, both CS and NS groups showed inhibition effects against the additional three days of demineralization in this study. Our findings demonstrate that SS-OCT signal analysis can be used to monitor the dentin demineralization and inhibition effects of desensitizers against dentin demineralization in vitro.

Author(s):  
Anna Lentzsch ◽  
Laura Schöllhorn ◽  
Christel Schnorr ◽  
Robert Siggel ◽  
Sandra Liakopoulos

Abstract Purpose To compare swept-source (SS) versus spectral-domain (SD) optical coherence tomography angiography (OCTA) for the detection of macular neovascularization (MNV). Methods In this prospective cohort study, 72 eyes of 54 patients with subretinal hyperreflective material (SHRM) and/or pigment epithelial detachment (PED) on OCT possibly corresponding to MNV in at least one eye were included. OCTA scans were acquired using two devices, the PLEX Elite 9000 SS-OCTA and the Spectralis SD-OCTA. Fluorescein angiography (FA) was used as reference. Two graders independently evaluated en face OCTA images using a preset slab as well as a manually modified slab, followed by a combination of en face and cross-sectional OCTA. Results Sensitivity (specificity) for the automated slabs was 51.7% (93.0%) for SS-OCTA versus 58.6% (95.3%) for SD-OCTA. Manual modification of segmentation increased sensitivity to 79.3% for SS-OCTA but not for SD-OCTA (58.6%). The combination of en face OCTA with cross-sectional OCTA reached highest sensitivity values (SS-OCTA: 82.8%, SD-OCTA: 86.2%), and lowest number of cases with discrepancies between SS-OCTA and SD-OCTA (4.2%). Fleiss kappa as measure of concordance between FA, SS-OCTA, and SD-OCTA was 0.56 for the automated slabs, 0.60 for the manual slabs, and 0.73 (good agreement) for the combination of en face OCTA with cross-sectional OCTA. Concordance to FA was moderate for the automated slabs and good for manual slabs and combination with cross-sectional OCTA of both devices. Conclusion Both devices reached comparable results regarding the detection of MNV on OCTA. Sensitivity for MNV detection and agreement between devices was best when evaluating a combination of en face and cross-sectional OCTA.


2017 ◽  
Vol 51 (4) ◽  
pp. 410-418 ◽  
Author(s):  
Rupert S. Austin ◽  
Maisalamah Haji Taha ◽  
Frederic Festy ◽  
Richard Cook ◽  
Manoharan Andiappan ◽  
...  

Swept-source optical coherence tomography (SS-OCT) shows potential for the in vivo quantitative evaluation of micro-structural enamel surface phenomena occurring during early erosive demineralization. This randomized controlled single-blind cross-over clinical study aimed to evaluate the use of SS-OCT for detecting optical changes in the enamel of 30 healthy volunteers subjected to orange juice rinsing (erosive challenge) in comparison to mineral water rinsing (control), according to wiped and non-wiped enamel surface states. Participants were randomly allocated to 60 min of orange juice rinsing (pH 3.8) followed by 60 min of water rinsing (pH 6.7) and vice versa, with a 2-week wash-out period. In addition, the labial surfaces of the right or left maxillary incisors were wiped prior to SS-OCT imaging. An automated ImageJ algorithm was designed to analyse the back-scattered OCT signal intensity (D) after orange juice rinsing compared to after water rinsing. D was quantified as the OCT signal scattering from the 33 µm sub-surface enamel, normalised by the total OCT signal intensity entering the enamel. The back-scattered OCT signal intensity increased by 3.1% (95% CI 1.1-5.1%) in the wiped incisors and by 3.5% (95% CI 1.5-5.5%) in the unwiped incisors (p < 0.0001). Wiping reduced the back-scattered OCT signal intensity by 1.7% (95% CI -3.2 to -0.3%; p = 0.02) in comparison to the unwiped enamel surfaces for both rinsing solutions (p = 0.2). SS-OCT detected OCT signal changes in the superficial sub-surface enamel of maxillary central incisor teeth of healthy volunteers after orange juice rinsing.


Diagnostics ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 658
Author(s):  
Federico Corvi ◽  
Federico Zicarelli ◽  
Matteo Airaldi ◽  
Salvatore Parrulli ◽  
Mariano Cozzi ◽  
...  

Background: To compare four different optical coherence tomography (OCT) devices for visualization of retinal and subretinal layers in highly myopic eyes. Methods: In this prospective, observational, cross-sectional study, consecutive patients with high myopia and control subjects were imaged by four OCT devices: Spectralis OCT2, PlexElite 2.0 100 kHz, PlexElite 2.0 200 kHz and the Canon Xephilio OCT-S1. The acquisition protocol for comparison consisted of single vertical and horizontal line scans centered on the fovea. Comparison between the devices in the extent of visible retina, presence of conjugate image or mirror artifacts, visibility of the sclerochoroidal interface and retrobulbar tissue. Results: 30 eyes with high myopia and 30 control subjects were analyzed. The visualized RPE length was significantly different between the OCT devices with Xephilio OCT-S1 imaging the largest extent (p < 0.0001). The proportion of eyes with conjugate image artifact was significantly higher with the Spectralis OCT (p < 0.0001), and lower with the PlexElite 200 kHz (p < 0.0001). No difference in visibility of the sclerochoroidal interface was noted among instruments. The retrobulbar tissue was visible in a higher proportion of eyes using swept-source PlexElite 100 kHz and 200 kHz (p < 0.007) compared to the other devices. Conclusions: In highly myopic eyes, the four OCT devices demonstrated significant differences in the extent of the retina imaged, in the prevalence of conjugate image artifact, and in the visualization of the retrobulbar tissue.


2021 ◽  
Author(s):  
Raphael Lejoyeux ◽  
Raphael Atia ◽  
Kiran Vupparaboina ◽  
Mohamed Ibrahim ◽  
Jose-Alain Sahel ◽  
...  

Abstract Purpose: To study the topographic distribution of the short posterior ciliary arteries (SPCA) entry sites into the choroid in normal eyes using structural en-face swept source optical coherence tomography (SS-OCT). Methods: Retrospective analysis of SS-OCT scans (wide-field structural SS-OCT 12x12mm) of 13 healthy subjects was performed. Cross-sectional swept-source OCT scans derived from a volume scan were represented as en-face image display following the Choroid-Scleral Interface to obtain en-face OCT. SPCAs in their last scleral location before choroidal entrance were identified manually, counted and localized by two masked observers. Correlations between two masked observers were analyzed using inter- and intra- class correlation. Results: Accuracy for the choroidal inner and outer border segmentation was 95-99%. Eighteen eyes from 13 normal subjects were included for SPCA analysis. The mean number of arteries was 13.8±3.5 per eye. Thirty-six percent were in the center of the posterior pole image; however, 21% were in the temporal part of the posterior pole. Median accuracy of the detection is 0.94. The correlation between the two observers was fair (0.54).Conclusion: Our algorithm allows visualization of the SPCA at the posterior pole of the eye using wide-field en-face SS-OCT. It can also help the clinicians to study the SPCAs in numerous ocular diseases, particularly its relationship with focal choroidal diseases.


2018 ◽  
Vol 103 (2) ◽  
pp. 216-221 ◽  
Author(s):  
Takao Hirano ◽  
Jyunya Kitahara ◽  
Yuichi Toriyama ◽  
Hirotsugu Kasamatsu ◽  
Toshinori Murata ◽  
...  

AimsTo evaluate quantitative metrics of the retinal microvasculature in eyes with diabetic retinopathy (DR) using various en face swept-source optical coherence tomography angiography (SS-OCTA) image sizes.MethodsNon-segmented and segmented images were acquired using an SS-OCTA device (PLEX Elite 9000; Carl Zeiss Meditec, Dublin, California, USA). The scanning protocols included the 3×3 mm, 6×6 mm and 12×12 mm fields of view. Quantitative analysis of the perfusion density (PD), vessel length density (VLD) and fractal dimension (FD) was performed. The area under the receiver operating characteristic curve was estimated to assess the ability of each image size to predict DR.ResultsThis prospective, cross-sectional study included 60 eyes, (non-DR, 13 eyes; non-proliferative DR (NPDR), 24 eyes; proliferative DR (PDR), 23 eyes) of 46 patients with diabetes and 21 eyes of 16 healthy individuals. In the 12×12 mm images, the PD of healthy individuals was significantly greater than that of patients with NPDR or PDR for all layers (NPDR, p<0.05; PDR, p<0.001 0.001; FD, p<0.001) or PDR (VLD, p<0.001; FD, p<0.001 for all layers). The results were similar for the 3×3 mm and 6×6 mm images. Overall, PD, VLD and FD progressively decreased with worsening DR severity in segmented and non-segmented layers for all SS-OCTA scan sizes. For detecting DR, 3×3 mm images best predicted DR for all evaluated quantitative parameters.ConclusionsVascular changes in DR can be monitored in detail through quantitative evaluations that combine different SS-OCTA scan sizes and parameters.


2020 ◽  
Vol 20 (1) ◽  
Author(s):  
A. R. Kee ◽  
V. C. H. Yip ◽  
E. L. T. Tay ◽  
C. W. Lim ◽  
J. Cheng ◽  
...  

Abstract Background To understand the differences between two different optical coherence tomography angiography (OCTA) devices in detecting glaucomatous from healthy eyes by comparing their vascular parameters, diagnostic accuracy and test-retest reliability. Methods A cross-sectional observational study was performed on healthy and glaucoma subjects, on whom two sets of OCTA images of optic disc and macula were acquired using both AngioVue (Optovue, USA) and Swept Source (Topcon, Japan) OCTA devices during one visit. A novel in-house software was used to calculate the vessel densities. Diagnostic accuracy of the machines in differentiating healthy versus glaucomatous eyes was determined using area under the receiver operating characteristic curve (AUROC) and test-retest repeatability of the machines was also evaluated. Results A total of 80 healthy and 38 glaucomatous eyes were evaluated. Glaucomatous eyes had reduced mean vessel density compared to healthy controls in all segmented layers of the optic disc and macula using AngioVue (p ≤ 0.001). However, glaucomatous eyes had higher mean vessel density on optic disc scans using Swept Source, with lack of statistically significant difference between healthy and glaucomatous eyes. The AUROC showed better diagnostic accuracy of AngioVue (0.761–1.000) compared to Swept Source (0.113–0.644). The test-retest reliability indices were generally better using AngioVue than Swept Source. Conclusions AngioVue showed better diagnostic capability and test-retest reliability compared to Swept Source. Further studies need to be undertaken to evaluate if there is any significant difference between the various machines in diagnosing and monitoring glaucoma.


2019 ◽  
Vol 2019 ◽  
pp. 1-9 ◽  
Author(s):  
Naresh Kumar Ravichandran ◽  
Hemanth Tumkur Lakshmikantha ◽  
Hyo-sang Park ◽  
Mansik Jeon ◽  
Jeehyun Kim

Bonding of braces is an essential part in contemporary orthodontic treatment. For the proper strength of bracket bonding, enamel conditioning or surface treatment on tooth surface is required. Treatment on the tooth surface such as prophylaxis smoothing with pumice and enamel etching results in considerable damages to the enamel surface of the tooth. In this study, we have proposed optical coherence tomography as a noninvasive imaging technique for the evaluation of damage induced during such treatment procedures. Using depth intensity analysis of the obtained cross-sectional images, the damage resulting to the enamel surface was studied after prophylaxis smoothening and etching steps.


2013 ◽  
Vol 5 (2) ◽  
pp. 31-33
Author(s):  
Prakash Lokhande

ABSTRACT Innovative technique has been introduced in the field of dentistry for the purpose of diagnosis and treatment. Technologies like laser, composite curing techniques, optical imaging have been utilized in the field of dentistry. OCT(optical coherence tomography) is a recent. technique which creates cross-sectional high resolution images. SS-OCT(Swept -Source optical coherence tomography) is a variant of optical coherence tomography, which provides instant imaging with high resolution, non-invasive and ease of handling. This article provides a overview of Swept -Source OCT and its application in the field of dentistry.


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