This PDF file contains the front matter associated with SPIE Proceedings Volume 10831, including the Title Page, Copyright information, Table of Contents, and Conference Committee listing.

Lasers usage in dentistry intend to be a more efficient way to cut and coagulate in comparison with traditional scalpel blades. The aim of this study is to evaluate the time efficiency for different surgical procedures of diode lasers compare with the classical cutting technique. Soft tissue modeling with this type of laser was slower, but in the whole management of these cases the economy of time during the healing process was analyzed. In this study the Epic X (Biolase) diode laser was used for performing three procedures: 1)gingivectomy, 2) a surgical procedure to discover of an impacted canine and 3)a vestibuloplasty. In the gingivectomy procedure, the final impression was possible in the same appointment, so it can be estimate a 14 days economy of time. When the impacted canine was discovered, cutting and coagulating with laser beam create the possibility to attach the bracket much more easy easy to the tooth, due to reduced bleeding and improved visibility. The same advantages were also during the vestibuloplasty procedure, which enable not to damage the mental nerve and the healing process was much quicker. In conclusion, using the laser for different surgical procedures in dentistry offer the advantages of better controlling the bleeding and also reducing the healing time.

Aim of the study. Marginal fit of the all ceramic chair side CAD CAM inlays evaluation.

Materials and methods. Inlay class II standardized preparations were performed on twelve natural teeth (molars) which were adapted and fixed on a typodont. Scanning of the cavities was done (Planmeca FIT) and the milling of the inlays was realized (Planmeca Mill 40). Light body silicone (Fit Checker II, GC, Tokyo, Japan) was injected on the preparations of the typodont model, and then each of the Empress CAD inlays were seated on the abutments under finger pressure, reproducing the clinical situation of the luting process. The marginal gap between the all ceramic inlays and the cavities was measured using microscopic photos of the silicone fit checker between the inlays and the cavities in 12 points/restoration. A calibration scale and imaging computer software (Image J) were used for the measurements.

Results The values measured for the occlusal cavity (marginal occlusal) were ranged between 19.026µ and 139.669µ and the values for the vertical cavity (marginal cervical) ranged between 69.256 µ and 295.091. Marginal openings below 100μ-120μ are clinically acceptable so there where some problems regarding the cervical fit.

Conclusion Within the limits of this study there were some cases with poor cervical marginal fit. Extensive studies could be useful for more accurate evaluations.

Digital impressions were introduced in order to overcome some inconveniences related to conventional impression materials.The aim of this in vitro study is to determine and evaluate the way the abutment geometry influences the accuracy of both, digital and conventional impressions. Crown preparations with occlusal convergence angles (0,6,10 and 20 degrees) were created from 4 resin maxillary right incisors.Each preparation was scanned using a high resolution scanner (reference scanner) and saved in stereolithography (STL) format. Then the prepared resin teeth were scanned (PlanScan group) using an intraoral scanner and saved in STL format as well.A number of three conventional polyvinyl siloxane (PVS) impressions were made from each preparation, which were poured with Type IV dental stone and scanned using the same intraoral scanner (PVS group). All STL files were compared using metrology software (Geomagic Studio 2013), in terms of trueness and precision. Based on the findings in this study, it may be concluded that the accuracy of digital impressions is superior to conventional methods, but the difference between them is not significant.

The potential for fabricating metallic dental components directly from digital data using alternative technologies is a topic of ongoing interest. The most recent developed procedures, like laser-based additive manufacturing methods represent an excellent opportunity to increase their application in achieving dental restorations. Purpose: The objective of the study was to assess the fracture behavior of metal-ceramic molar crowns obtained with laser-based additive manufacturing methods related to other manufacturing procedures of the metallic frameworks. Materials and methods: For the experimental analyses metal-ceramic crowns were prepared using alternative technologies for the frameworks: traditional casting (CST), computerized milling (MIL), selective laser sintering (SLS) and selective laser melting (SLM). These were veneered with specific hot-pressed ceramics. Crowns were cemented on duplicated composite dies and tested under compressive load to fracture. Results: Maximal compressive loads were registered. The mean registered values were 2432.93 N for CST, 1955.02 N for MIL, 2104.96 N for SLS and 2141.76 N for SLM. Higher variations between the samples were registered for samples with frameworks obtained with additive manufacturing methods. Conclusion: Application of laser-based additive manufacturing methods is currently a challenge in dental alloys processing. The mechanical behavior of metal-ceramic crowns obtained with different manufacturing technologies is important from clinical point of view and should be related to other structural and morphological characteristics of the frameworks.

Interactions between oral environment and dental alloys can impair metal framework of dental restorations, due to corrosion compounds. The aim of the study was to determine corrosion resistance of dental Co-Cr alloys obtained by modern technologies, as selective laser sintering (SLS) and selective laser melting (SLM), depending on microstructure, pH and surface preparation. Materials and method: A commercial Co-Cr powder was used to prepare metallic plates both SLS and SLM technologies. Relief-firing under argon was conducted, and also oxide-firing. All specimens were polished. Half of them were air-blasted with 75 μm Al2O3 particles for ceramic veneering. Both polished and air-blasted samples, were divided into three groups, and exposed to different pH solutions: 2, 7 and 11. The degree of corrosion inhibition was determined for all specimens. Results: Lowest corrosion rate was observed in electrolyte with pH of 11, and the highest in pH of 2. Surface roughness pay an essential role, proved by the higher corrosion rate of the surfaces prepared for ceramic veneering. This is why corrosion behavior at metal-ceramic interfaces shows some particularities. Conclusions: Loss of adhesion at metal-ceramic interface is accentuated by oral environment through the intervention of corrosion on metal surfaces prepared for veneering.

Objectives: The aim of the present study was to assess the capability of the VELscope system to image the tissue autofluorescence of potentially malignant oral lesions and to assess the diagnostic accuracy, sensitivity, and specificity of this method.

Methods: 10 patients were evaluated by conventional oral examination (COE) followed by direct visual fluorescence evaluation (DVFE) using VELscope. Areas clinically suspicious detected by COE or with positive DVFE (visual fluorescence loss (VFL)) have been further investigated using surgical biopsy. The association between COE and DVFE has also been assessed and compared with the gold standard, i.e. histopathology.

Results: Eight positive biopsies for malignant lesions were detected using COE and DVFE. Only one positive biopsy for a premalignant lesion was not in accordance with COE and DVFE. One of the lesions, determined on the VELscope and COE as a non-malignant lesion was also confirmed by the biopsy. Therefore, the VELscope system had a sensitivity of 100% and specificity of 50% in discriminating in situ normal mucosa from carcinoma or invasive carcinoma, compared with histology. The predictive positive value was 88.89% and the negative predictive value was 100% (95% confidence interval).

Conclusions: DFVE allows for simple and cost-effective margin determinations, in order to detect and screen oral precancerous and early cancerous disorders. We found that for the moment the VELscope system could not replace the histopathology procedure. Nonetheless, its usefulness for clinical examination was determined, as well as for monitoring oral lesions and guiding biopsies. Therefore, this method may add sensitivity to oral tissue examinations and be an effective adjunct procedure for high-risk patients.

The healing process of bone defects is time consuming, and new bone generation takes place slowly because of decreased blood supply to the fracture site and insufficiency of calcium and phosphorus to strengthen and harden new bone. In addition, large defects, also known as critical bone defects, may not heal spontaneously and lead to nonunion prognosis due to the size of defects or unstable biomechanical properties, unfavorable wound environment, suboptimal surgical technique, metabolic factors, hormones, nutrition, and applied stress.

There are limited clinical trials that deal with the influence of photodynamic therapy (PDT) in addition to conventional scaling and root planing (SRP), due to the clinical and biological parameters of periodontitis. The scope of this review is to evaluate the interest for photodynamic therapy (PDT) over the last 10 years, as an alternative to traditional methods, more comfortable for all patients. Randomized controlled trials, systematic reviews, in the last 10 years were identified, all of them having PDT compared to conventional non-surgical treatment as FMD and medication. Data on changes in clinical and microbiological parameters were extracted. Screening, data abstraction and quality assessment were conducted. There were clinical heterogeneities among included studies. PDT as an independent treatment or as an adjunct to SRP did not demonstrate major statistically or clinically significant advantages. Combined therapy of PDT + SRP indicated a probable efficacy in CAL gain or probing depth reduction.

Dental caries are multifactorial, transmissible and infectious diseases, caused mainly by the complex interaction of cariogenic oral flora (bacterial biofilm) with fermentable alimentary carbohydrates on the tooth surface, over a period of time. The aim of this study was to evaluate the residual caries using a fluorescent lamp, caries detection dye, as well as combining these two methods in the diagnosing phase. The sample consisted of 4 patients with age between 23-29, from which were evaluated 10 dental units (9 molars and 1 premolar) with uncomplicated carious process of the occlusal surface and no other oral pathologies. First of all, was performed an initial clinical and x-ray exam, after that the carious process was removed. The next step was represented by visual and tactile examination of excavated cavity and the examination with UV lamp was also performed. These two methods of examination were performed after that together with revealing substance. The value obtained by using the revealing substance and lamp exams are insignificantly higher than the ones obtained through the revelling substance (p=0.414 with the significance threshold of α=0,05). Using the fluorescent lamp is more efficient than using caries revealing substances, because the substances need to be used carefully, and only as an adjuvant of the clinical exam, since these can lead to an over-preparation.

A short-review of optical coherence tomography (OCT) technologies employed to evaluate and image flow and tiny movements is presented. Over the time, the progress of OCT from time domain to spectral (Fourier) domain SD-OCT has led to new approaches in measuring flow and tissue (object) vibration. In the present document, several procedures are presented of what is known today as OCTA, used to visualize tiny vessels in the human retina and replacing the need for injection in angiography. These methods are now extended to measurements of minuscule spatial variations due to action potential, cell division or tissue deformation in elastography.

Non-destructive sensing and imaging within the body of materials is essential for quality control and very importantly for the development of new materials, equally for industrial and medical applications. Conventional non-destructive testing (NDT) methods, such us ultrasound, exhibit low imaging resolutions, of hundreds of microns and typically require a direct contact between the probe and the sample to be investigated. The speed at which the standard NDT methods performs is also quite restricted. The development of optical coherence tomography (OCT) applications in the field of NDT have grown immensely over the past years, offering faster, higher resolution images in a completely contactless environment with the sample. Optical Coherence Tomography brings a plethora of benefits to the current non-destructive methods. However, a multitude of challenges still need to be overcome to truly make OCT the technique of choice for NDT applications. In this paper, a short overview of the main challenging of producing cross-sectional, transversal and volumetric OCT images are presented with an emphasize on OCT’s capabilities and limitations in producing images in real-time. Real-time OCT images of various samples produced using the Master/Slave technique developed within the Applied Optics Group at the University of Kent are demonstrated.

With the advent of instruments incorporating elements of confocal microscopy and Optical Coherence Tomography (OCT), optical technologies are steadily gaining usage in a variety of biomedical applications. They offer tissue visualization both at the superficial level and in depth, they operate using non-ionizing radiation at a relatively low cost, and the procedures are easily tolerated by patients. One area of growth for optical imaging is in the oral cavity, which has excellent optical accessibility both for dental tissue and oral mucosa. The need to image features accurately (both as part of oral mapping and as part of investigating the underlying tooth structure) requires producing 3-D volumes with sufficiently good lateral and vertical resolution to allow identification of features of interest. Although a few types of intraoral optical scanners are already successfully commercialized for surface mapping, the examination of optical design considerations that are particular to scanned beam imaging in the oral cavity does highlight particular challenges of interest to both clinicians and optical engineers engaged in designing the next generation of optical instruments.

In this brief review we point to very fresh publications illustrating the latest developments in imaging techniques that are able to tackle biological samples, with particular emphasis on brain/neurons. Visualizing living cells/neurons, single molecules, and even ions/atoms is crucially important, but, unfortunately, excruciatingly difficult. Still, recent progress reveals that a wide variety of novel/enhanced imaging techniques is reaching maturity. We will recap here the principles behind techniques that allow imaging beyond the diffraction limit, and highlight a few fresh advances when modeling for neuroscience (as a result of such imaging techniques). These include among others: interferometric scattering microscopy, atomic force microscopy (contact and dynamic modes), multiparametric, molecular recognition, multifrequency and high-speed imaging. As yet another example, single-particle tracking is one of several tools able to study single molecules inside cells/neurons, hence revealing the dynamics of biological processes (e.g., receptor trafficking, signaling and cargo transport). Obviously, with such improvements in resolving power new avenues for studying/modeling synapses, axons and neurons more generally are being opened. Finally, a few of the latest experiments that highlight unique capabilities will be mentioned, and their implications for advancing modeling and for achieving a much better functional understanding of neurons will be brought to light.

Collageneus tissues manifest strongly pronounced viscoelastic behavior. Namely, viscosity leads to time-dependence of the deformation processes. This concerns both compression (loading) and unloading of the tissue. Both processes can be characterized by a relaxation time - the time during which the strain changes e-times. We demonstrate the applicability of the OCT-based 2D relaxography to characterize local relaxation time of collageneous tissues. The developed technique can be used for further investigation of the viscoelastic properties of healthy and pathological collageneous tissues.

In this report we discuss some practical obstacles/pitfalls arising in realization of quantitative compressional OCE, as well as discuss possible ways of their resolution. More specifically we consider (i) complications in quantification of the Young modulus of tissues related to influence of partial adhesion between the OCT probe and pre-calibrated reference layers - "compliant sensors", (ii) distorting influence of surface curvature/corrugation on strain distribution in the tissue bulk, (iii) ways of enhancement of effective SNR in OCT-based strain mapping without periodic averaging, and (iv) potentially significant influence of nonlinearity of the elastic response of biological tissues on quantification of their stiffness.

Optical Coherence Tomography (OCT) is a technology capable of producing 3-D volumes of microscopic structures with micron-scale resolution. Its main area of application remains ophthalmology and in particular retinal imaging. The quality and usability of the images depends upon the frame rate and the properties of the light being used. Swept source OCT (SS-OCT) can offer a speed advantage; variants using polygon mirrors (PMs) as spectral filters in SS-OCT have resulted in a variety of different arrangements. Although their application has been successfully demonstrated, a more detailed study of the particular aspects and requirements of beam propagation through the filter and their overall impact on the system performance have not been reported. Examining aspects related to vignetting at the PM facet leads to maximizing light throughput and system performance, which is the aim of this work. A swept source spectral filter consisting of a transmission grating, a two-lens telescope, an off-axis PM, and an end reflector mirror has been evaluated in terms of the beam width at the PM facet and how this parameter varies across the entire width of the spectrum at the input of the spectral filter.

"Table tops"/occlusal veneers are partial crowns that allow for the biomimetic restoration of worn teeth in bruxing patients. The biomimetic approach includes a CAD/CAM composite resin for the manufacturing of the "table tops", for example Tizian, which is a zirconia reinforced composite (Schutz Dental Group). In the present study we prove the value of a fast swept source optical coherence tomography (SS-OCT) system in the evaluation of the marginal fit of Tizian "table tops". 12 maxillary first premolars were extracted and minimally invasive prepared for "table tops". The Tizian "table tops" were then adhesively cemented on the natural teeth with Variolink II (Ivoclar Vivadent). A SS-OCT system has been used to evaluate the marginal and internal adaptation of Tizian "table tops". The SS (Axsun Technologies, Billerica, MA) has a central wavelength of 1060 nm, a sweeping range 106 nm (quoted at 10 dB), and a 100 kHz line rate. The depth resolution of the system, measured experimentally in air was 10 μm. The same samples were analyzed by using a micro-computed tomography (μCT) system, in order cu confirm the data obtained by using OCT. The imaging system used for this study offers good spatial resolutions in both directions, transversal and longitudinal, of around 10 μm, a high sensitivity, and it is also able to acquire entire 3D volumes as fast as 2.5 s. Once the full dataset has been acquired, rendered high resolutions en-face projections could be produced. With it, the "table top" – cement – abutment tooth interfaces were observed on both C-scans as 2D images and also in the 3D reconstructions; the system was able to detect several open interfaces, which were confirmed on the μCT images. The SS-OCT system allows for an efficient evaluation of biomimetic Tizian "table tops".

Technological improvements and the progress of new adhesive materials have led to the development of minimally invasive restorations, like overlays; these are also indicated in the treatment of pathological tooth wear caused by bruxism. In this study we evaluated the marginal adaptation of Tizian overlays through two non-invasive methods: digital microscopy and confocal laser scanning microscopy. 12 maxillary first premolars were extracted and prepared for overlays. The Tizian overlays were cemented with Variolonk II (Ivoclar Vivadent). The marginal adaptation of each specimen was analyzed, on all four surfaces, with a digital microscope at 40x to 800x magnification ratio; we also used a confocal laser scanning microscope, at 10x magnification, in Z mode, with 10 μm slices and a resolution of 1020 x 1024. The exposure time per pixel was 8 μs and the wavelength of the laser was set at 405 nm, corresponding to a blue light laser. We concluded that confocal laser scanning microscopy, with its a higher horizontal and vertical resolution with regard to digital microscopy, and with its volumetric reconstructions capability of the sample image, is therefore a more appropriate method for this particular dental field, i.e., to investigate the marginal adaptation of Tizian overlays.

Dental indirect veneers have become the most functional and cost-effective method for providing high-aesthetic results whenever smile design enhancement is required. Yet, clinical failures have been reported due to the detachment of the veneers from the dental hard tissues, as well as to chipping and microleakage. Many experimental studies have been conducted in order to identify clinical and technical solutions for enhancing the adhesive and biomechanical properties of the veneers, by promoting the same classical, linear marginal contour of these particular indirect restorations. Thus, the aim of this study is to develop a novel design of the veneers deemed to augment the interfacial adhesive forces and, furthermore, to investigate the bonded interfaces by using optical coherence tomography.

Orthodontic treatments imply the use of different types of adhesives and brackets. However, concerns have been raised regarding the effect of these treatments on the structure of the involved teeth. The debonding process is especially regarded as a concern: due to the use of different pliers tensile and pulling forces the develop on the surface of the tooth. The finishing bur is also a concern. Optical Coherence Tomography (OCT), an emerging technology that performs transverse sections of biological systems has been used in order to obtain a more accurate assessment of enamel quality due to its wide applicability and to its non-invasive properties.OCT, analogous to ultrasound imaging(with the difference that it uses light instead of sound), provides cross-sectional images of the tissue structure on the micron scale, in vivo and in real time. Regarding fixed orthodontic treatments, patients are often subjected in the process to a high risk of enamel decalcification and carious processes. Demineralization usually occurs in the area adjacent to the orthodontic bracket location, where bacterial plaque control is difficult. Therefore, in this study we evaluate using OCT the degree of demineralisation produced in the enamel structure, following the removal of the orthodontic bracket. Also, the amount of adhesive remnants after the removal of the adhesive and the finishing of the dental surface with specific instrumentation is evaluated.

The aim of this study was to evaluate a relatively new calcium silicate cement (Biodentine(R)) used as a dentine substitute. The marginal adaptation in Class II restorations have been studied; this is the spot, where gingival margins are situated apical to the cemento-enamel junction (CEJ). 20 Class II cavities have been prepared on mesial and distal surfaces of 10 extracted teeth, with margins extending 1 mm below the cementum-enamel junction. Cavities have been restored with composite resin and Biodentine(R) in an "open sandwich" technique. The assessment of the marginal adaptation was performed using Laser Scanning Confocal Microscopy. The considered interfaces have been evaluated and the differences between the different materials have been discussed. In conclusion, contemporary calcium silicate materials, such as Biodentine, can be used as substitute materials for the dentin. However, because Biodentine needs extensive time to set, the operating time is longer than when a Resin-Modified Glass-Ionomer (RMGI) is used.

A remarkable progress has been made over the last decades on regular structures having dimensions similar to, or even smaller than the wavelengths of light. Such regular structures exhibit peculiar behaviors when interacting with light travelling through them - in quite different way from what would be expected from classical optics - like, for example, inhibition of light transmission and photonic band gap formation. As a noteworthy example we mention the exploits of photonic crystals properties in the field of supercontinuum lasers. This paper will briefly review photonic crystals by going over their basic topologies, as well as comparing their capabilities and range of medical applications. Our directions of research in this respect are pointed out.

To determine the roughness is an important aspect in both industrial and biomedical applications. We propose and utilize for roughness evaluations, a non-destructive evaluation methods, Optical Coherence Tomography (OCT). For the metallic surfaces investigated from this point of view, the Ra and Rz parameters are utilized, according to ISO 4287/1988. Also, according to ISO 4280 and ISO 3274 standards, the measurements have been made on 12.5 mm portions. In order to accommodate such evaluations with the specific OCT field-of-view, four consecutive OCT images have been made for each sample, and an appropriate processing of the data collected from the surface profiles has been made. A validation of the results obtained with OCT has been completed with the gold standard for such evaluations, using a contact mechanical method, with a Mitutuyo profiler.

1) Background: One of the key factors for a successful endodontic therapy is to adequately fill the root canals. The aim of this in vitro study was to compare the quality of three different techniques of root canal obturation: tapered singlecone, cold lateral condensation, warm vertical condensation and injection system, using non-invasive Optical Coherence Tomography (OCT). 2) Materials and methods: A total of 30 extracted single-rooted teeth, prepared with Reciproc System (VDW, silver Reciproc ) were divided into three groups, based on the filling method: the first group obturated with “single-cone” (n=10) Reciproc guttapercha single-cone tapered according to the diameter, length and conicity of the preparation, the second group obturated with cold lateral condensation (n=10) and the third group, “combined-system” (EQ META BIOMED) (n=10). OCT technology can generate high-resolution cross-sectional imaging, capable to evaluate the micro-leakages of dental restorations and endodontic fillings. 3) Results: OCT showed that none of the root canal filled teeth were gape-free; the highest percentage of filling material was observed in the combined system group (warm vertical and injection system). 4) Conclusions: OCT represents a valuable method for investigation with high depth resolution which can be used for evaluation of endodontic fillings.