Luana Osório Fernandes

Non-Invasive Periodontal Probing Through Fourier-Domain Optical Coherence Tomography.

BACKGROUND Periodontitis is a multifactorial and infectious disease that may result in significant debilitation. The aim of this study is to exploit two optical coherence tomography (OCT) systems operating in the Fourier domain at different wavelengths, 930 and 1,325 nm, for structural analysis of periodontal tissue in porcine jaws. METHODS Five fresh porcine jaws were sectioned and stored in formalin before OCT analysis. Two- and three-dimensional OCT images of the tooth/gingiva interface were performed, and measurements of the gingival structures were obtained. The 930-nm OCT system operates in the spectral domain, whereas the 1,325-nm system is a swept-source model. Stereomicroscope images, the gold standard, were used for direct comparison. RESULTS Through image analysis, it is possible to identify the free gingiva and the attached gingiva, the calculus deposition over tooth surfaces, and the subgingival calculus that enables the enlargement of the gingival sulcus. In addition, the gingival thickness and the gingival sulcus depth can be non-invasively measured, varying from 0.8 to 4 mm. CONCLUSIONS Regarding the ability of the two OCT systems to visualize periodontal structures, the system operating at 1,325 nm shows a better performance, owing to a longer central wavelength that allows deeper tissue penetration. The results with the system at 930 nm can also be used, but some features could not be observed due to its lower penetration depth in the tissue.

Comparative analysis of gingival phenotype in animal and human experimental models using optical coherence tomography in a non-invasive approach

Imaging methods are widely used in diagnostic and among the diversity of modalities, optical coherence tomography (OCT) is nowadays commercially available and considered the most innovative technique used for imaging applications, in both medical and non-medical applications. In this study, we exploit the OCT technique in the oral cavity for identification and differentiation between free and attached gingiva, as well as determining the gingival phenotype, an important factor to determination of periodontal prognosis in patients. For the animal studies, five porcine jaws were analyzed using a Swept Source SS-OCT system operating at 1325nm and stereomicroscope, as gold pattern. The SSOCT at 1325nm was chosen due to the longer central wavelength, that allows to deeper penetration imaging, and the faster image acquisition, an essential factor for clinical setting. For the patient studies, a total of 30 males and female were examined using the SS-OCT at 1325nm and computer controlled periodontal probing. 2D and 3D images of tooth/gingiva interface were performed, and quantitative measurements of the gingival sulcus could be noninvasively obtained. Through the image analysis of the animals jaws, it was possible to quantify the free gingiva and the attached gingiva, the calculus deposition over teeth surface and also the subgingival calculus. For the patient’s studies, we demonstrated that the gingival phenotype could be measured without the periodontal probe introduction at the gingival sulcus, confirming that OCT can be potentially useful in clinic for direct observation and quantification of gingival phenotype in a non-invasive approach.

Optical coherence tomography follow‐up of patients treated from periodontal disease

Optical coherence tomography (OCT) is one of the most important imaging modalities for biophotonics applications. In this work, an important step towards the clinical use of OCT in dental practice is reported, by following-up patients treated from periodontal disease (PD). A total of 147 vestibular dental sites from 14 patients diagnosed with PD were evaluated prior and after treatment, using a swept-source OCT and two periodontal probes (Florida probe and North Carolina) for comparison. The evaluation was performed at four stages: day 0, day 30, day 60 and day 90. Exceptionally one patient was evaluated 1-year after treatment. It was possible to visualize in the two-dimensional images the architectural components that compose the periodontal anatomy, and identify the improvements in biofilm and dental calculus upon treatment. In the follow-up after the treatment, it was observed in some cases decrease of the gingival thickness associated with extinction of gingival calculus. In some cases, the improvement of both depth of probing with the traditional probes and the evidence in the images of the region was emphasized. The study evidenced the ability of OCT in the identification of periodontal structures and alterations, being an important noninvasive complement or even alternative for periodontal probes for treatment follow-up. OCT system being used in a clinical environment. Above OCT image (left) prior treatment and (right) 30 days after treatment.

Optical coherence tomography as a method for quantitative skin evaluation in systemic sclerosis

Improved, non-invasive techniques for the diagnosis, classification and monitoring of patients with systemic sclerosis (SSc) are needed. One potential technique for quantifying the extent of cutaneous sclerosis in these patients is optical coherence tomography (OCT).1 ,2 Recently, Abignano et al 3 suggested the use of OCT as a feasible and reliable technique to evaluate skin fibrosis in SSc. Based on that initial work, the aim of this study was to evaluate OCT images and compare the findings with the modified Rodnan skin score (mRSS) in patients with SSc. Thirty-three Brazilian patients with SSc (28 women; mean age 46.1 years; range 19–71 years) were recruited and fulfilled criteria for SSc proposed by American College of Rheumatology (ACR), 19804 or ACR/European League Against Rheumatism, 2013.5 Patients were classified into limited SSc (n=18) and diffuse SSc (n=15) groups. The mean disease duration was 9.7 years (median 8 years, range 2–26 months). Thirty-five healthy control (HC) (28 women, …

Non-invasive diagnostic and monitoring of periodontal disease through optical coherence tomography: validation of the technique with animal model and patients

We propose the application of optical coherence tomography as an auxiliary tool for periodontal disease diagnostic, and demonstrated in three stages: animal modeling, healthy patients and follow up of disease regression upon treatment.

Monitoring the gingival regeneration after aesthetic surgery with optical coherence tomography

The aim of this study was to use the Optical Coherence Tomography (OCT) technique working in spectral domain (Swept Source OCT at 1325 nm, Thorlabs, New Jersey, USA) to monitor the tissue repair in patients undergoing periodontal plastic surgery. The evaluations were done over a period of 60 days. It was observed that 15 days after periodontal surgery the gum was still in different healing process as compared to the observation after 60 days. Thus it is clear that, despite some technical limitations, the OCT is an efficient method in the evaluation of regeneration gingival.

Optical coherence tomography investigations of ceramic lumineers

Lumineers are veneer laminates used as an alternative for aesthetic dental solutions of the highest quality, but the only current means of its performance assessment is visual inspection. The objective of this study was to use the Optical Coherence Tomography (OCT) technique working in spectral domain to analyze in vivo in a single patient, 14 lumineers 180 days after cementation. It was possible to observe images in various kinds of changes in the cementing line and the laminate. It was concluded that the OCT is an effective and promising method to clinical evaluation of the cementing line in lumineers.

Study of lumineers' interfaces by means of optical coherence tomography

OCT has been used to evaluate dental materials, and is employed here to evaluate lumineers for the first time. Lumineers are used as esthetical indirect restoration, and after wearing and aging, several undesirable features such as gaps, bubbles and mismatch can appear in which would only be seen by invasive analysis. The OCT (spectral domain SD-OCT, 930nm central wavelength) was used to evaluate noninvasively the lumineercement-tooth interface. We analyzed 20 specimens of lumineers-teeth that were prepared in bovine teeth and randomly allocated in 4 experimental groups (n=5) with two different cementation techniques and two different types of cementing agent (RelyX U200 and RelyX Veneer, 3M ESPE, with the adhesive recommended by the manufacture). The lumineers were made of lithium disilicate and obtained using a vacuum injection technique. The analysis was performed by using 2D and 3D OCT images, obtained before and after cementing and the thermal cycling process to simulate thermal stress in a oral cavity. Initial measurements showed that the SD-OCT was able to see through the 500μm thick lumineer, as delivered by the fabricant, and internal stress was observed. Failures were found in the cementing process and also after ageing simulation by thermal cycling. The adhesive failures as bubbles, gaps and degradation of the cementation line are the natural precursors of other defects reported by several studies of clinical follow-up (detachments, fractures and cracks). Bubble dimensions ranging from 146 μm to 1427 μm were measured and the OCT was validated as an investigative and precise tool for evaluation of the lumineer-cement-tooth.OCT has been used to evaluate dental materials, and is employed here to evaluate lumineers for the first time. Lumineers are used as esthetical indirect restoration, and after wearing and aging, several undesirable features such as gaps, bubbles and mismatch can appear in which would only be seen by invasive analysis. The OCT (spectral domain SD-OCT, 930nm central wavelength) was used to evaluate noninvasively the lumineer- cement-tooth interface. We analyzed 20 specimens of lumineers-teeth that were prepared in bovine teeth and randomly allocated in 4 experimental groups (n=5) with two different cementation techniques and two different types of cementing agent (RelyX U200 and RelyX Veneer, 3M ESPE, with the adhesive recommended by the manufacture). The lumineers were made of lithium disilicate and obtained using a vacuum injection technique. The analysis was performed by using 2D and 3D OCT images, obtained before and after cementing and the thermal cycling process to simulate thermal stress in a oral cavity. Initial measurements showed that the SD-OCT was able to see through the 500μm thick lumineer, as delivered by the fabricant, and internal stress was observed. Failures were found in the cementing process and also after ageing simulation by thermal cycling. The adhesive failures as bubbles, gaps and degradation of the cementation line are the natural precursors of other defects reported by several studies of clinical follow-up (detachments, fractures and cracks). Bubble dimensions ranging from 146 μm to 1427 μm were measured and the OCT was validated as an investigative and precise tool for evaluation of the lumineer-cement-tooth.