Influence of the Text Neck Posture on the Static Dental Occlusion.

Background and Objectives: The excessive use of smartphones for various tasks led to a new adverse postural phenomenon called text neck. The aim of this study was to investigate the effect of the text neck posture (TNP) on static occlusion by using the T-Scan III occlusal diagnostic system. Materials and Methods: Nineteen subjects (aged 20 to 24 years) were considered for this research. They had normal values for anterior overbite and overjet, Angle Class I occlusion, no posterior crossbite, and no signs or symptoms of cervical or temporo-mandibular disorders. Occlusal registrations were performed with the T-Scan III system in a normal, neutral head posture (NHP), as well as in the TNP. The investigated parameters were: occlusion time (OT), asymmetry index of the occlusal force (AOF), percent of the maximum movie force (%MMF), and the time elapsed from the last occlusal contact until the maximum intercuspation (MAT-OTB). The last three parameters were analyzed in the maximum area frame (MA) of the registrations. For the statistical analysis of the recorded data, the Wilcoxon Signed Ranks test and the Spearman's correlation coefficient were used. Results: The following values were obtained in NHP and in TNP: for AOF, 14.88 ± 10.39% and 18.04 ± 12.83%, respectively; for OT, 1.34 ± 1.84 s and 1.32 ± 1.8 s, respectively; for the %MMF, 97.5 ± 2.83% and 96.31 ± 3.17%, respectively; for MAT-OTB, 2.08 ± 1.82 s and 1.45 ± 2.3 s, respectively. There were no statistically significant differences between the static occlusal parameters measured in NHP and those in TNP. However, the high values of the AOF and OT in NHP revealed an imbalance of the occlusal force distribution between the right and left side in maximum intercuspation (MI), as well as a lack of simultaneity of static occlusal contacts. Furthermore, there was a significant, direct, and strong correlation between OT and AOF in NHP. Conclusions: The NHP should not be used as the starting position in TNP simulations in T-Scan studies, so as to avoid statistically insignificant differences between static occlusion in NHP and TNP. The healthy standing subjects, with normal occlusal relationships from the clinical point of view, revealed an occlusal instability in NHP when examined with the T-Scan.

Additive Manufactured Polymers in Dentistry, Current State-of-the-Art and Future Perspectives-A Review.

3D-printing application in dentistry not only enables the manufacture of patient-specific devices and tissue constructs, but also allows mass customization, as well as digital workflow, with predictable lower cost and rapid turnaround times. 4D printing also shows a good impact in dentistry, as it can produce dynamic and adaptable materials, which have proven effective in the oral environment, under its continuously changing thermal and humidity conditions. It is expected to further boost the research into producing a whole tooth, capable to harmoniously integrate with the surrounding periodontium, which represents the ultimate goal of tissue engineering in dentistry. Because of their high versatility associated with the wide variety of available materials, additive manufacturing in dentistry predominantly targets the production of polymeric constructs. The aim of this narrative review is to catch a glimpse of the current state-of-the-art of additive manufacturing in dentistry, and the future perspectives of this modern technology, focusing on the specific polymeric materials.

Comparative Assessment of the Shaping Ability of Reciproc Blue, WaveOne Gold, and ProTaper Gold in Simulated Root Canals.

Maintaining the original trajectory of the root canal is a major challenge in endodontic therapy, especially in narrow and curved root canals. The present study aims to assess the shaping capacity of three endodontic systems made of different nickel−titanium alloys on simulated curved root canals. Thirty-six endodontic resin blocks (Ref. V040245, VDW) divided into three groups, each of twelve blocks (n = 12), were shaped, photographed, and analyzed: Group 1-Protaper Gold (PTG) (Dentsply Maillefer, Ballaigues, Switzerland) F2 25/08; Group 2-Reciproc Blue (RB), RB 25/08 (VDW, Munich, Germany); Group 3-WaveOne Gold (WOG) (Dentsply Maillefer), WOG 25/07. Each block was standardized and photographed before and after shaping in the same position, with the foramen oriented to the left. Post-shaping images were superimposed onto the initial ones. Thirteen measurement points were used for evaluation, spaced with 1 mm distance from one another, from level 0, apical foramen, to level 12, coronal orifice. The amount of removed resin from inner (X1) and outer (X2) walls, the direction of transportation (X1 − X2), and the centering ability (X1 − X2)/Y were measured, calculated, and comparatively analyzed. Statistical differences (p < 0.05) were observed between the shaping capacity of the considered systems in the middle and coronal thirds. PTG had a better centering ability than WOG and RB in the coronal third, while RB was more centered in the middle third in comparison to both WOG and PTG. In the apical third, the centering capacity of WOG was higher, without being statistically significant. WOG 25/07 and PTG 25/08 tend to cut more on the inner wall of the root canals, and RB 25/08 on the external one.

Emerging Technologies for Dentin Caries Detection-A Systematic Review and Meta-Analysis.

This systematic review and meta-analysis aimed at assessing the diagnostic accuracy of emerging technologies, such as laser fluorescence (LF), transillumination, light-emitting diode devices, optical coherence tomography (OCT), alternating current impedance spectroscopy, fluorescence cameras (FC), photo-thermal radiometry, and modulated luminescence technology. In vivo and in vitro results of such non-ionizing, non-invasive, and non-destructive methods' effectiveness in non-cavitated dentin caries detection are sometimes ambiguous. Following the PRISMA guidelines, 34 relevant research articles published between 2011-2021 were selected. The risk of bias was assessed with a tool tailored for caries diagnostic studies, and subsequent quantitative uni- and bi-variate meta-analysis was carried out in separate sub-groups according to the investigated surface (occlusal/proximal) and study setting (in vivo/in vitro). In spite of the high heterogeneity across the review groups, in vitro studies on LF and FC proved a good diagnostic ability for the occlusal surface, with area under the curve (AUC) of 0.803 (11 studies) and 0.845 (five studies), respectively. OCT studies reported an outstanding performance with an overall AUC = 0.945 (four studies). Promising technologies, such as OCT or FC VistaProof, still need well-designed and well-powered studies to accrue experimental and clinical data for conclusive medical evidence, especially for the proximal surface. Registration: INPLASY202210097.

Evaluation of the Shaping Ability of Three Thermally Treated Nickel-Titanium Endodontic Instruments on Standardized 3D-printed Dental Replicas Using Cone-Beam Computed Tomography.

Background and Objectives: The aim of the present study is to compare the efficacy of three root canal preparation systems in the shaping of 3D-printed root canal replicas of single rooted teeth. Materials and Methods: Sixty 3D-printed root canal replicas were produced and divided into three groups, each consisting of twenty samples. Each group was shaped with a different instrument: Reciproc Blue R25/08 (VDW GmbH, Munich, Gemany), WaveOne Gold Primary 25/07 (Dentsply Sirona, Ballaigues, Switzerland), and ProTaper Gold F2 25/08 (Denstply Sirona). To ensure the reproducibility of pre- and post-operative CBCT images of the root canals, the endodontic printed replicas were placed in a mould of silicon impression material. A cone-beam computed tomography (CBCT) software was used to compare pre- and post-instrumentation images collected at three levels of the root canal length: 3, 6, and 9 mm from the apical foramen. The amount of transportation, centring ability, and curvature angle after shaping were evaluated for each system. The results were statistically analysed and compared using one-way analysis of variance (ANOVA). Results: Regarding the transportation of the root canal after shaping, significant differences between groups at 3 mm (p = 0.010721) and 6 mm (p = 0.000046) were recorded in the mesio-distal direction, while in the bucco-lingual significant differences were only observed at 6 mm (p = 0.000554). Reciproc Blue removed more dentin from the mesial and buccal wall of the root canal. When evaluating the centring ability of the three systems, significant differences were observed between the groups at the level of 9 mm (p = 0.037258) in the mesio-distal direction, and at the level of 6 mm (p = 0.038197) in the bucco-lingual direction. Significant differences of the canal curvature angle after shaping were also observed between groups (p = 0.000001). Reciproc Blue straightened the curvature the most, while ProTaper Gold the least. Conclusions: All systems produced minor root canal transportation. No instrument was able to achieve a perfect centring preparation of the root canal. All systems produced a small degree of root canal straightening.

En-face optical coherence tomography analysis of gold and silver nanoparticles in endodontic irrigating solutions: An in vitro study.

Optical coherence tomography (OCT) is a non-invasive, non-radioactive optical diagnostic method based on low-coherence interferometry, which achieves images with different orientation. In dentistry, its major advantage is represented by the localization and characterization of the smallest defects in hard dental tissues, dental materials and of the smallest details in dental anatomy (supplementary canals, recesses, isthmuses, or intra-radicular connections). The aim of the present in vitro study was to evaluate using c-scan en-face optical coherence tomography, the optical opacity, and the distribution inside the root canal lumen of several extracted human teeth of silver and gold nanoparticles from special irrigating solutions used in endodontic treatment. Twelve root canals from 5 human teeth were instrumented using the ProTaper Universal system after initial negotiation with hand K-files ISO no. 10 and rotary nickel-titanium PathFile instruments. An initial c-scan OCT analysis was performed for each sample to confirm that the root canal lumen was empty from radiopaque materials (Group 1). Teeth were first irrigated with NanoCare Plus (Group 2) and then with NanoCare Gold (Group 3) and C-scans were repeated after each irrigation method. The OCT investigation started at the tooth apex, at a depth of 1 mm from its tip. Subsequently, 100 slices of 10 microns were obtained from each root canal. Images were captured and then analyzed with ImageJ software to calculate the level of grey inside the root canal lumen. The highest values of grey were obtained in the samples irrigated with NanoCare Gold after NanoCare Plus (Group 3). The present study proved that both nanoparticles inserted in root canal irrigants were evidenced through OCT imagistic analysis due to their optical opacity, which allowed their highlighting in an empty root canal lumen, after the endodontic treatment was performed and the root canal was cleaned and shaped using specific protocols.

Scaffold-Type Structure Dental Ceramics with Different Compositions Evaluated through Physicochemical Characteristics and Biosecurity Profiles.

The design and development of ceramic structures based on 3D scaffolding as dental bone substitutes has become a topic of great interest in the regenerative dentistry research area. In this regard, the present study focuses on the development of two scaffold-type structures obtained from different commercial dental ceramics by employing the foam replication method. At the same time, the study underlines the physicochemical features and the biological profiles of the newly developed scaffolds, compared to two traditional Cerabone® materials used for bone augmentation, by employing both the in vitro Alamar blue proliferation test at 24, 48 and 96 h poststimulation and the in ovo chick chorioallantoic membrane (CAM) assay. The data reveal that the newly developed scaffolds express comparable results with the traditional Cerabone® augmentation masses. In terms of network porosity, the scaffolds show higher pore interconnectivity compared to Cerabone® granules, whereas regarding the biosafety profile, all ceramic samples manifest good biocompatibility on primary human gingival fibroblasts (HGFs); however only the Cerabone® samples induced proliferation of HGF cells following exposure to concentrations of 5 and 10 µg/mL. Additionally, none of the test samples induce irritative activity on the vascular developing plexus. Thus, based on the current results, the preliminary biosecurity profile of ceramic scaffolds supports the usefulness for further testing of high relevance for their possible clinical dental applications.

Cognitive dysfunction in young subjects with periodontal disease.

BACKGROUND: Periodontal disease is an inflammatory, dysbiotic condition. Studies have shown that in the elderly, periodontal disease was associated with cognitive dysfunction and Alzheimer's disease. OBJECTIVE: To investigate whether young healthy subjects with periodontal disease have lower cognition compared to those without periodontal disease. The salivary cytokines (IL-1ß, TNF-α) levels in relation to cognition were also tested. METHODS: In a monocenter, cross-sectional study, forty subjects [mean age (SD) = 34 (5) and 48% female] from western Romania were classified into periodontal disease conditions using radiographic assessment: 10 subjects had aggressive periodontitis (AGG_P), 20 chronic mild-moderate periodontitis (CR_P), and 10 no periodontitis (NL_P). Neuropsychological assessment performed by standardized neurologists and psychologist included Rey Auditory Verbal Learning Test (RAVLT), Montreal Cognitive Assessment test (MOCA), Mini-Mental State Examination (MMSE), and Prague tests. Salivary cytokines levels were determined by ELISA. RESULTS: RAVLT and MOCA delayed recall scores were lower in AGG_P group compared to NL_P and CR_P. The learning curve was also different with subjects with AGG_P showing reduced learning performance. Contrary to our hypothesis, salivary IL-1ß associated with immediate but not delayed cognitive scores. CONCLUSIONS: These results showed for the first time that subjects with AGG_P had cognitive dysfunction and IL-1ß may play a role in this process.

Endodontic fillings evaluated using en face OCT, microCT and SEM.

OBJECTIVES: The goal of endodontic therapy is mechanically cleaning and shaping the root canal system, the removal of organic and inorganic debris followed by sealing with permanent filling materials. MATERIALS AND METHODS: Therefore, the aim of this in vitro study was to engage three imagistic methods: (i) en face (ef) time domain (TD) optical coherence tomography (OCT), (ii) micro-computed tomography (µCT), and (iii) scanning electron microscopy (SEM), in terms of their efficiency in assessing the quality of endodontic fillings. So far, is settled that efOCT images can identify defects∕voids in several of the investigated root canal fillings and identify gaps of 50 µm. RESULTS: The results delivered by µCT technology also showed several imperfections of the endodontic filling but also at the interfaces formed by the sealer and the root canal walls. SEM investigations highlights the complex form of the interface formed the endodontic filling material and the walls of the root canal, as well as shortcomings of the materials from several samples. Gaps of 50 µm are identified with efOCT. CONCLUSIONS: The net advantage of OCT technology, in respect to the other two technologies consists in its non-invasiveness. The OCT axial resolution is also sufficient to see the material gaps. Another advantage of efOCT investigations is that they allow real-time imaging of complex arrangement at the interfaces of the filling material with dentinal root.

Morphological aspects in remineralizing potential of Silver Diamine Fluoride.

OBJECTIVES: The purpose of this study was to demonstrate the efficacy of Silver Diamine Fluoride (SDF) antibacterial solution in penetrating the demineralized areas of enamel. MATERIALS AND METHODS: It was considered a group of four extracted teeth (with no color fading, fissures, decay, or demineralization). Each tooth was sectioned in two equal parts, in mesio-distal direction, using a dental handpiece and a special rounded, flat bur. Each specimen was demineralized, for one minute, with 45% orthophosphoric acid, on occlusal and proximal zones. The specimens were then washed and dried with water-air dental syringe. All the probes were inspected with an optical microscope and enamel thickness was digitally measured. Advantage Arrest (Elevate Oral Care, USA), which contains SDF, was applied on the previous demineralized zones. The penetration of the substance was visually inspected with the optical microscope and electronically measured. RESULTS: It was observed an improvement in remineralizing the white spots on enamel surfaces, the optical microscope being able to detect both demineralization and the penetration of SDF through enamel. CONCLUSIONS: Based on our in vitro study, SDF (Advantage Arrest) was capable to induce/increase enamel remineralization, through SDF penetration.

The use of baropodometric analysis in musculoskeletal disorders of dentists working in orthostatic posture - a series of 3 cases.

INTRODUCTION: Musculoskeletal disorders (MSDs) caused by incorrect working posture among dentists is a serious issue and one that leads to decreased productivity and quality of life. AIM: The aim of this study was to evaluate the impact of MSDs caused by postural errors in dental healthcare professionals on the body's center of gravity through a new and innovative technique - baropodometry. METHODS: In this study we included 3 oral healthcare specialists with over 20 years experience of practicing in orthostatism, with confirmed work-related MSDs, and performed a baropodometric analysis on them. RESULTS: According to the analysis, all 3 test subjects had alterations of the body's center of gravity, with uneven distribution of pressures on the feet being recorded by the baropodometer. CONCLUSION: In an effort to maintain a good field of view and workplace in orthostatism, the subject is forced to adopt an non-ergonomic position that leads to uneven weight distribution, shifted center of gravity that eventually cause musculoskeletal disorders.

Dental Adhesive Interfaces Reinforced with Magnetic Nanoparticles: Evaluation and Modeling with Micro-CT versus Optical Microscopy.

Dental adhesives are used in a wide range of applications, including to place direct composite restorations in frontal or posterior teeth. One of the most frequent causes for the failure of composite resin restorations is microleakages. The first aim of this work is to introduce a new type of self-etched dental adhesive doped with magnetic nanoparticles (MPs) synthetized in the laboratory. The scope is to produce adhesives with a minimized width/thickness to decrease the risk of microleakages. The second aim is to assess the width/thickness of the adhesive layer in all the characteristic areas of the teeth using both the less precise but most common optical microscopy and the more accurate and volumetric micro-Computed Tomography (CT) investigations. Twenty extracted teeth have been divided into four groups: Group 1 includes 'blank' samples with adhesives that are not doped with MPs; Group 2 includes samples with adhesives doped with MPs; Groups 3 and 4 include samples with adhesives doped with MPs that are subjected to an active magnetic field for 5 and 10 min, respectively. Microscopy investigations followed by micro-CT and EDAX are performed on the adhesive. While a rather good agreement is obtained between the microscopy and micro-CT results, the capability of the latter to offer a full volumetric reconstruction of the layer is exploited to analyze the adhesion of the four considered dental materials. Thus, from micro-CT results the graphs of the surface areas as functions of the adhesive layer width are modeled mathematically, as well as the volume of sealants, for each of the four groups. To our knowledge, it is the first time that such a methodology is used. Characteristic parameters are extracted and the ascertainment of the optimal parameter that should be utilized for such assessments is discussed. The study demonstrates the adhesion improvement produced for Groups 3 and 4, where MPs are used. It also concludes that the magnetic field should be applied to the adhesive material for the longest possible exposure time (with a trade-off with the clinical duration of the treatment).

The use of thermal imaging in evaluating musculoskeletal disorders in dentists.

Musculoskeletal disorders (MSDs) caused by incorrect working positions among dentists is a serious health issue and one that leads to decreased productivity and quality of life. Muscle activity and strain is correlated with higher surface temperatures due to increased metabolic activity [2]. The main objective of this study is to evaluate, using thermal imaging, the muscular strain experienced by oral healthcare professionals during work depending on their position, and to assess whether periodic stretching exercises have an impact on preventing MSDs. The study included four subjects and used thermal imaging to evaluate the heat pattern produced by muscle strain in two different states, one while working in incorrect postures and the other after performing stretching exercises. We used a FLIRB200 thermal imaging camera to measure skin surface temperature changes of the underlining muscles in the cervical, right arm triceps, and lumbar areas. According to the imaging, all four subjects recorded a drop in temperature in evaluated muscle regions after performing stretching exercises, corresponding to a decrease in muscle strain. Thermal imaging can be effectively used to evaluate muscle strain and MSDs. Stretching exercises could be viewed as effective preventive measures to avoid MSDs caused by erroneous work postures, however, more subjects are required to draw a definite conclusion.

Periodontal disease in a young Romanian convenience sample: radiographic assessment.

BACKGROUND: The goal of this study was to determine the distribution of periodontal disease in a population seeking oral rehabilitation in a Romanian prosthodontics department and to identify the factors associated with each type of periodontal condition. METHODS: The study population consisted of patients presenting consecutively to the Prosthodontics Department of the Faculty of Dental Medicine, Victor Babes University of Medicine and Pharmacy, Timisoara. The diagnosis and classification of periodontal conditions, as well as dental pathologies and conditions, were based on examination of panoramic radiographs. A standardized questionnaire was administered to obtain socio-demographic characteristics (age, gender, ethnicity, education, residency, marital status), medical history, dental/periodontal history (family history of periodontal disease), and behavior (smoking, brushing, flossing and regular cleaning). RESULTS: Among subjects presenting to the Prosthodontics department, only 34.2% were periodontal disease-free and 65.8% had periodontal disease, of which 11.4% had aggressive periodontitis. In univariate models, age, education, marital status, smoking, and tooth number were associated with chronic periodontitis. Age, education, family history, smoking, and tooth number were associated with aggressive periodontitis. However, in a multivariable model, only age, tooth number and family history were significant. CONCLUSIONS: This study found a high prevalence of periodontal disease in patients seeking oral rehabilitation from the Prosthodontics department. Age, tooth number and family history of periodontal disease were associated with the type of periodontal disease. These results suggest the need for periodontal examination prior to prosthetic oral rehabilitation in this population.

Micro-CT and optical microscopy imagistic investigations of root canal morphology.

Protecting the root's internal morphology is the first key toward the success of the endodontic treatment. Due to the vast diversity of endodontic space, it is difficult to visualize and to establish the shape and limits of the root canal, especially the morphology of apical area and lateral root canals. Optical microscopy is a classical imagistic investigation method, widely used along classical methods like radiographs that also offer limited information about root morphology and extension of decay. Micro-computed tomography (micro-CT), a modern imagistic investigation method can provide detailed three-dimensional reconstructions of root canal. Micro-CT is a non-invasive method that has the possibility to offer cross-sectional and axial images of the endodontic space. The success of root canal treatment is based on cleaning and shaping. Beyond these two procedures, sealing the endodontic space by respecting its limits is another prerequisite for long-term success of endodontic therapy. Micro-CT can perform three-dimensional reconstruction of the root canal, root canal filling and can provide accurate images of the endodontic space. The assessment of root morphology can be obtained through imagistic invasive optical microscopy and already mentioned non-invasive methods (micro-CT). The aim of this study is to illustrate and analyze the endodontic space, according to its diversity by using micro-CT, a non-invasive imagistic investigation method an also optical microscopy. The two techniques can also provide the extension of carries or demineralized substance on different levels of the root.

Noninvasive Quantitative Evaluation of the Dentin Layer during Dental Procedures Using Optical Coherence Tomography.

A routine cavity preparation of a tooth may lead to opening the pulp chamber. The present study evaluates quantitatively, in real time, for the first time to the best of our knowledge, the drilled cavities during dental procedures. An established noninvasive imaging technique, Optical Coherence Tomography (OCT), is used. The main scope is to prevent accidental openings of the dental pulp chamber. Six teeth with dental cavities have been used in this ex vivo study. The real time assessment of the distances between the bottom of the drilled cavities and the top of the pulp chamber was performed using an own assembled OCT system. The evaluation of the remaining dentin thickness (RDT) allowed for the positioning of the drilling tools in the cavities in relation to the pulp horns. Estimations of the safe and of the critical RDT were made; for the latter, the opening of the pulp chamber becomes unavoidable. Also, by following the fractures that can occur when the extent of the decay is too large, the dentist can decide upon the right therapy to follow, endodontic or conventional filling. The study demonstrates the usefulness of OCT imaging in guiding such evaluations during dental procedures.

Design and testing of prototype handheld scanning probes for optical coherence tomography.

Three simple and low-cost configurations of handheld scanning probes for optical coherence tomography have been developed. Their design and testing for dentistry applications are presented. The first two configurations were built exclusively from available off-the-shelf optomechanical components, which, to the best of our knowledge, are the first designs of this type. The third configuration includes these components in an optimized and ergonomic probe. All the designs are presented in detail to allow for their duplication in any laboratory with a minimum effort, for applications that range from educational to high-end clinical investigations. Requirements that have to be fulfilled to achieve configurations which are reliable, ergonomic-for clinical environments, and easy to build are presented. While a range of applications is possible for the prototypes developed, in this study the handheld probes are tested ex vivo with a spectral domain optical coherence tomography system built in-house, for dental constructs. A previous testing with a swept source optical coherence tomography system has also been performed both in vivo and ex vivo for ear, nose, and throat-in a medical environment. The applications use the capability of optical coherence tomography to achieve real-time, high-resolution, non-contact, and non-destructive interferometric investigations with micrometer resolutions and millimeter penetration depth inside the sample. In this study, testing the quality of the material of one of the most used types of dental prosthesis, metalo-ceramic is thus demonstrated.

Zirconia enriched dental adhesive: a solution for OCT contrast enhancement. Demonstrative study by synchrotron radiation microtomography.

OBJECTIVE: The major aim of this study was to prove the capability of the optical coherence tomography (OCT) method in visualizing the integrity of the adhesive fillings and of the interfaces between the adhesive, tooth structures and composite resin. As zirconium dioxide was added to the composition of the adhesive layer in order to strengthen the backscattered light in the OCT investigation, for a better visualization of the interfaces, the determination of a proper zirconia concentration was another aim of our study. METHOD: Several class II cavities were prepared in human premolars and were filled with dental adhesive containing different zirconia concentrations and light-curing composite resin. Both OCT and synchrotron radiation microtomography (micro-CT) were used to analyse the morphology of the tooth-adhesive-composite interfaces and to investigate the adhesive layer. RESULTS: The pore distribution, both at the interfaces level and in the resin, and the analysis of the adhesive layer integrity were obtained. A good agreement between OCT and micro-CT analyses was observed in terms of detecting discontinuities in the adhesive layer. Furthermore, micro-CT showed that zirconia percentages in the adhesive higher than 20 vol.% lead to conglomerates formation, which can negatively influence mechanical properties. Meanwhile, OCT confirmed a factor of 3 for the contrast enhancement when 20% of zirconia was included in the adhesive composition. SIGNIFICANCE: The present study proved the capability of the OCT method in visualizing the morphology and integrity of zirconia doped tooth adhesive fillings, to be used for a further in vivo tool development.

Quantitative evaluation of dental abfraction and attrition using a swept-source optical coherence tomography system.

A fast swept-source optical coherence tomography (SS-OCT) system is employed to acquire volumes of dental tissue, in order to monitor the temporal evolution of dental wear. An imaging method is developed to evaluate the volume of tissue lost in ex vivo artificially induced abfractions and attritions. The minimal volume (measured in air) that our system could measure is 2352 µm3. A volume of 25,000 A-scans is collected in 2.5 s. All these recommend the SS-OCT method as a valuable tool for dynamic evaluation of the abfraction and attrition with remarkable potential for clinical use.

En face optical coherence tomography investigation of apical microleakage after laser-assisted endodontic treatment.

The aim of our study was to evaluate the potential of en face optical coherence tomography (OCT) for the detection of apical microleakage after 980 nm and 1,064 nm laser-assisted endodontic treatment. Ninety, human, single-rooted teeth with one straight root canal and closed apices were used. All roots were prepared biomechanically to the working length at an apical size 30 and 0.06 taper. The teeth were divided into three equal groups of 30 samples each, according to the treatment to be applied to the root canal. Group I received 980 nm diode laser (3 W, 0.01 s on time, 0.01 s off time, 5 s per procedure, four procedures); group II received neodymium:yttrium-aluminum-garnet (Nd:YAG) laser (1.5 W, 15 Hz, 5 s per procedure, four procedures). In group III the root canals were approached conventionally only. In all groups the root canal filling was performed with AH Plus endodontic sealer and gutta-percha points. An en face OCT prototype was used for the investigation of apical microleakage. According to one-way analysis of variance (ANOVA) and en face OCT, the number of defects in the laser groups was significantly lower (P < 0.005) than in the control group. No statistical differences were noted between the laser groups (P = 0.049). En face OCT imaging proved that laser-assisted endodontic treatment improved the prognosis of root canal filling and led to a reduction in apical microleakage.