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Remineralization effects when using different methods to apply fluoride varnish in vitro

Available online 1 September 2018
Journal of Dental Sciences

Abstract

Background/purpose

Remineralization efficacy for early caries lesion may change when fluoride varnish (FV) is applied directly or indirectly to the lesion. This in vitro study compared direct and indirect remineralization efficacies of FV on artificial caries lesions and evaluated acid-resistance of lesion remineralized by FV and artificial saliva.

Materials and methods

One hundred and twenty-six bovine demineralized specimens were allocated to four varnish groups (Duraphat®, EnamelPro®, MI™, and ClinproWhite™, n = 28 each) and a negative-control group (n = 14). Half of specimens from each varnish group had the FV applied and the other specimens didn’t. The specimens treated and not treated with the FV were immersed together in 20 mL of artificial saliva at 37 °C for 24 h. Then the applied FV was removed carefully from the specimen, and immersion process was continued in fresh artificial saliva for 48 h. The negative-control group was immersed in artificial saliva for same time as in varnish groups. The acid resistance of remineralized specimens from varnish groups was compared to negative-control group. Vickers microhardness number (VHN) was measured to evaluate re-demineralization effect.

Results

The ΔVHN was significantly higher for indirect remineralization (134.4 ± 31.5, mean ± SD) than for direct remineralization (66.8 ± 27.9). All varnish groups showed significant differences between the direct and indirect application methods. The acid resistance of remineralized specimens was higher in the all FV groups than in the negative-control.

Conclusion

This in vitro study confirmed that the remineralization effect of fluoride varnishes would be higher in the vicinity than the underneath of the varnish treated surface.
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Research and Education Loss of tooth structure associated with preparation for two monolithic CAD-CAM complete coverage restorations

Abstract

Statement of problem

Different techniques are used to fabricate complete coverage restorations. Each fabrication technique requires a specific preparation design that may violate a principle of tooth preparation, that is, conservation of tooth structure.

Purpose

The purpose of this in vitro study was to compare the volume of loss of mandibular first molar structure associated with a preparation for computer-aided design and computer-aided manufacturing (CAD-CAM) versus conventionally fabricated complete coverage restorations.

Materials and methods

Fifty artificial mandibular right first molars were weighed before and after preparation for complete coverage restorations of the following types: complete cast, monolithic zirconia, monolithic pressed lithium disilicate, monolithic milled lithium disilicate, and metal-ceramic crowns (n=10 per method). Tooth mass loss was measured by subtracting the mass after preparation from the mass before the preparation, and tooth volume loss was calculated by dividing the mass by the density of the material. A robust analysis of variance (ANOVA), followed by a post hoc test, was used to compare the volume of tooth loss (α=.01).

Results

Mean tooth volume losses were 255.6 mm3, 270.0 mm3, 312.7 mm3, 331.7 mm3, and 309.9 mm3 for complete cast, monolithic zirconia, monolithic pressed lithium disilicate, monolithic milled lithium disilicate, and metal-ceramic crowns, respectively. Teeth prepared for monolithic CAD-CAM zirconia and lithium disilicate crowns did not exhibit a significantly lower (P>.01) decrease in volume loss than with complete cast and monolithic pressed lithium crowns.

Conclusions

Preparation of teeth for monolithic CAD-CAM complete coverage restorations is not associated with a significantly higher volume of tooth loss than their conventionally fabricated counterpart preparations.
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Systematic Review Intraoral scan bodies in implant dentistry: A systematic review

Abstract

Statement of problem

Intraoral scan body (ISB) design is highly variable and its role in the digital workflow and accuracy of digital scans is not well understood.

Purpose

The purpose of this systematic review was to determine the relevant reports pertaining to ISBs with regard to design and accuracy and to describe their evolution and role in the digital dentistry workflow. Special attention was placed on their key features in relation to intraoral scanning technology and the digitization process.

Materials and methods

A MEDLINE/PubMed search was performed to identify relevant reports pertaining to ISB usage in dentistry. This search included but was not limited to scan body features and design, scan body accuracy, and scan body techniques and the role of ISBs in computer-aided design and computer-aided manufacturing (CAD-CAM) processes. Commercially available scan bodies were examined, and a patient situation was shown highlighting the use of ISBs in the digital workflow.

Results

Deficiencies in the reports were found regarding various scan body topics, including ISB features/design, accuracy, and the role of ISBs in CAD-CAM processes.

Conclusions

ISBs are complex implant-positioning-transfer devices that play an essential role in the digital workflow and fabrication of accurately fitting implant-supported restorations. With scanner technology rapidly evolving and becoming more widespread, future studies are needed and should be directed toward all parts of the digital workflow when using ISBs. By understanding the basic components of ISBs and how they relate to digital scanning and CAD-CAM technology, more emphasis may be placed on their importance and usage in the digital workflow to ensure accurate transfer of implant position to the virtual and analog definitive cast. Efforts should be made by clinicians to identify an optimal ISB design in relation to the specific intraoral scanning technology being used.
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Carestream Dental’s New CBCT System Drives Precision Through Intelligence


ATLANTA—Today at CDA North, Carestream Dental launched an all-new imaging system: The CS 9600 cone beam computed tomography (CBCT) system, which enables new levels of image quality, usability and, ultimately, precise diagnostic capabilities. 
Featuring intelligent automation, first-time-right imaging technology and highly simplified workflows, this system ensures reliable patient positioning, reproducible results and exceptional images. For a future beyond today, the CS 9600 can also grow with a doctor’s practice—thanks to upgradeable fields of view, versatile imaging options and intuitive software.
Blending 2D panoramic technology, CBCT scanning, 3D model/impression scanning1 with 3D facial scanning,2 the CS 9600 can also be upgraded to include cephalometric imaging.2 Three different editions, featuring 10, 12 and 14 fields of view, can be upgraded to a larger FOV without replacing the unit—ensuring that the system covers all the needs of practices that place implants, perform oral and maxillofacial surgery or perform orthodontic, periodontal or endodontic procedures.
“Digital dentistry is in a constant state of change,” Ed Shellard, D.M.D, chief dental officer, Carestream Dental, said. “We not only want to enable doctors to keep up with these changes, but we also want them to use these innovations to their fullest potential. The CS 9600 is an intelligent and powerful imaging system that allows users of any experience level to capture high-quality diagnostic images.”
A prime example of the CS 9600’s intelligent features is the SmartPad, an intuitive touchscreen interface that guides the operator through the exam and simplifies procedures from exam setup to image quality control. The unique live positioning assistant utilizes cameras to properly position the patient—with no need for laser beams. Combined with optional Scout scan and face-to-face positioning, this unique technology helps the operator capture the right image the first time. The operator can also verify the image quality immediately after the acquisition on the high-resolution touch screen using quality control tools.
The CS 9600’s SmartAuto technology further enhances workflow automation and exam precision. SmartAuto Pan3 captures the patient’s jaw shape and position in three dimensions and automatically calculates the correct exposure settings and trajectory, while SmartAuto 3D3 enables users to precisely define the field of view position on a low dose scout view, virtually eliminating the risk of incorrect positioning for repeatable image quality each time.
Images are further enhanced thanks to the CS 9600’s patented CS MAR3 technology. Carestream Dental’s high-end MAR algorithm provides specific metal artifact reduction and a unique tool to dynamically compare images with and without the MAR filter; helping to confirm diagnosis and reducing the risk of misinterpretation.
The CS 9600 also helps to address concerns regarding patient safety and adherence to the ALARA (as low as reasonably achievable) principle. With its low dose programs, the CS 9600 delivers 3D images at a significantly lower dose than 2D panoramic imaging; helping to protect patients.
Another new feature to the CS 9600 is an integrated retractable seat,3 which enables users to scan patients either in a comfortable seated position when higher stability is required or rotated out of the way when not in use or to accommodate patients in wheelchairs.
“These unique features all add up to deliver what every doctor is seeking: Exceptional image quality,” Shellard said. “When you can position the patient better the first time; capture images faster; and not have to worry about things like metal artifacts, it ultimately means you’re getting the best image, every time.”
The CS 9600 is supported by Carestream Dental’s newest imaging platform: CS Imaging version 8. This updated software enables one-stop access to all 2D images, 3D images and CAD/CAM data through a single system. Additional modules, such as the Prosthetic-Driven Implant Planning module, CS Airway, CS Model and CS Model+, can be integrated with CS 9600 to expand diagnoses and treatment planning capabilities. The CS 9600 will also be fully integrated into Carestream Dental’s suite of practice management software including CS PracticeWorks, CS SoftDent, CS OrthoTrac and CS WinOMS.
Carestream Dental’s CS Advantage comprehensive service offering further enhances doctors’ CS 9600 investment. For example, the innovative CS UpStream advanced monitoring service continuously screens the CS 9600 system and—by monitoring its historical behavior—prevents downtime and maximizes system availability. CS Advantage members also get extended warranty coverage, software updates, training and support to ensure the best ownership experience.
To learn more about the groundbreaking CS 9600, or any of Carestream Dental’s innovative technology, visit Carestream Dental in booth #1112, call 800.944.6365 or visit carestreamdental.com.
1Work in progress, not available for sale
2Option: work in progress, not available for sale
3Option
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About Carestream Dental

Carestream Dental provides industry-leading dental digital product lines and services, including imaging equipment, CAD/CAM systems, software and practice management solutions, for dental and oral health professionals. With more than 100 years of industry experience, Carestream Dental technology captures two billion images annually and aids in more precise diagnoses, improved workflows and superior patient care. For more information or to contact a Carestream Dental representative, please call 800.944.6365 or visit carestreamdental.com.

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Review Article Effects of blue-light irradiation during dental treatment

Available online 31 August 2018

Summary

In dentistry, blue light is widely used for tooth bleaching and restoration procedures involving composite resin. In addition, many dentists use magnification loupes to enable them to provide more accurate dental treatment. Therefore, the use of light is indispensable in dental treatment. However, light can cause various toxicities, and thermal injuries caused by light irradiation are regarded as particularly important. In recent years, the eye damage and non-thermal injuries caused by blue light, the so-called “blue light hazard”, have gained attention. Unfortunately, much of the research in this field has just begun, but our recent findings demonstrated that blue-light irradiation generates reactive oxygen species (ROS) and induces oxidative stress in oral tissue. However, they also showed that such oxidative stress is inhibited by antioxidants. There have not been any reports that suggested that the ROS-induced phototoxicity associated with blue-light irradiation causes direct clinical damage, but some disorders are caused by the accumulation of ROS. Therefore, it is presumed that it is necessary to suppress the accumulation of oxidative stressors in oral tissues during treatment. In the future, we have to promote discussion about the suppression of phototoxicity in dentistry, including concerning the use of antioxidants to protect against phototoxic damage.
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Comparison of sealing ability of ProRoot mineral trioxide aggregate, biodentine, and ortho mineral trioxide aggregate for canal obturation by the fluid infiltration technique

Abstract

Background: Adequate seal of the root canal is necessary to prevent recontamination and ensure
the long‑term clinical success. The aim of this study was to evaluate the sealing ability of ProRoot
mineral trioxide aggregate (MTA), Biodentine, and Ortho MTA as the root canal obturation materials
using the fluid infiltration method.
Materials and Methods: In this invitro study a total of 66 extracted human mandibular
premolars were randomly divided into five groups according to the material used for the root
canal obturation. Group I ‑ ProRoot MTA (20 samples), Group II ‑ Biodentine (20 samples),
Group III ‑ Ortho MTA (20 samples), Group IV ‑ negative group (3 samples), and Group V‑positive
group (3 samples). MTA, Biodentine, and Ortho MTA were applied using a cotton‑tipped K‑file
#30 and hand plugger into the root canals of each group. In Group 4 (negative control), no
filling material was used. In Group 5 (positive control), a single gutta‑percha size #40 was
inserted into the root canal without using a sealer. The teeth were mounted and exposed to
the fluid infiltrarion system. Statistical analysis was performed using Kruskal–Wallis test the level of significance was set at α = 0.05.
Results: Mean values of microleakage in MTA ProRoot, Biodentine and Ortho MTA groups
were 1.83 ± 0.62, 1.95 ± 1.27 and 1.72 ± 0.83 μL in 8 minutes. No statistically significant difference was observed between the sealing ability of ProRoot MTA, Biodentine, and Ortho
MTA (P = 0.091).
Conclusion: Within the limitations of this study, microleakage values were similar to MTA ProRoot,
Biodentine, and Ortho MTA using the fluid infiltration technique.
Key Words: Dental leakage, filtration, mineral trioxide aggregate, root canal filling materials
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