Abstract: A dental appliance for positioning a patient's teeth includes a removable orthodontic tooth positioning appliance having teeth receiving cavities shaped to directly receive at least some of the patient's teeth and apply a resilient positioning force to the patient's teeth. The appliance includes a hard polymer layer having a hard polymer layer elastic modulus disposed between a first soft polymer layer having a first soft polymer layer elastic modulus and a second soft polymer layer having a second soft polymer layer elastic modulus. The hard polymer layer elastic modulus is greater than each of the first soft polymer layer elastic modulus and the second soft polymer layer elastic modulus. At least one of the first soft polymer layer and the second soft polymer layer has a flexural modulus of greater than about 35,000 psi.

Abstract: A surgical instrument for use in a sinus lift procedure and methods for performing sinus lift procedures. A surgical instrument includes a shank having a body portion, a first end, an opposite second end, and a neck portion disposed between the body portion and the first end. The shank body portion defines a first longitudinal axis and the neck portion defines a second longitudinal axis. The shank further defines a head coupled with the first end. The head includes a flat proximal surface that extends radially outward of the neck portion and a domed distal surface opposite the first proximal surface. The second longitudinal axis is perpendicular to the proximal surface.

Abstract: The invention relates to a dental prosthesis part production method, wherein: a dental prosthesis part model is generated taking into account a dental model; a load analysis of the dental prosthesis part model is carried out; a first reinforcing structure model having a first shape and position is arranged inside the dental prosthesis part model and the dental prosthesis part model is reduced by a volume corresponding to the arranged first reinforcing structure model; the reduced dental prosthesis part model is divided into a lower partial volume and an upper partial volume; a lower part of the dental prosthesis part is produced from a first composite material according to the lower partial volume by means of the 3D printer; a first reinforcing structure corresponding to the first reinforcing structure model is arranged on the first part of the dental prosthesis part; and, by means of the 3D printer using the first composite material, an upper part of the dental prosthesis part according to the upper partial

Abstract: An orthodontic aligner includes a first plastic segment having a first shape that fits over a first portion of a dental arch of a patient, a second plastic segment having a second shape that fits over a second portion of the dental arch of the patient, and a connector that joins the first plastic segment to the second plastic segment. The connector is configured to be disposed along a lingual side of one or more additional teeth of the patient without exerting a clinically significant force on the one or more additional teeth. The connector spans a gap between the first plastic segment and the second plastic segment, the gap corresponding to the one or more additional teeth that are not to receive the clinically significant force. The connector includes a flexible material that will perform at least one of flex, move or change shape responsive to applied forces.

Abstract: Provided is an apparatus for measuring implant osseointegration, and the apparatus for measuring implant osseointegration includes: a vibration generation unit configured to apply multiple vibrations with frequencies in different bands, respectively, to an implant fixture; a vibration sensor configured to measure three-axis vibration information of the implant fixture caused by the vibrations from the vibration generation unit; and a control unit configured to determine the degree of osseointegration based on the measured vibration information.

Abstract: A pontic device for preserving soft tissue in a tooth-extraction site includes a generally curved apical end. The apical end has a first perimeter and is configured to rest in a tooth extraction socket and substantially conform to soft tissue of a tooth-extraction site immediately after a tooth has been extracted. The pontic device further includes an opposing, generally concave coronal end. The coronal end has a second perimeter that is configured to substantially correspond to and form a seal with gingival tissue surrounding the tooth-extraction site. The coronal end is configured to receive a tooth-shaped coronal pontic portion to form a final restoration.

Abstract: A mouth piece removal tool. The mouthpiece removal tool includes an elongated handle having a first end opposite a second end. A first hook extends perpendicular from the second end of the elongated handle. The first hook includes a pointed tip curving upwards.

Abstract: An image generation system for implant diagnosis includes a first image information acquirement apparatus acquiring first three-dimensional (3D) image data about a mouth area of a target patient, a second image information acquirement apparatus acquiring second 3D image data by scanning plaster patterns of teeth of the target patient, and a data processing apparatus receiving and matching the first 3D image data and the second 3D image data and generating synthetic 3D image data. In the image generation system, the plaster patterns of teeth are provided with a matching reference marker for matching the first 3D image data and the second 3D image data, and the data processing apparatus pre-matches the first 3D image data and the second 3D image data based on a coordinate of a matching reference marker of the second 3D image data.

Abstract: Disclosed is a computer-implemented method of designing a number of dental restorations for a patient, wherein the method includes: selecting a composed set of teeth including a number of teeth, where the number of teeth are arranged spatially relative to each other forming a high aesthetic composition; applying the composed set of teeth to a virtual three dimensional representation of the patient's present oral situation to obtain an initial set of teeth; optionally modifying one or more parameters of one or more of the teeth in the initial set of teeth to obtain a finalized set of teeth.

Abstract: A device for mitigation of temporomandibular joint disorder with lingual tooth surface contact surface, hard palate conformity, anterior pad, and pad wings.

Abstract: A radio frequency identification (RFID) system for detecting and identifying lost dentures in a facility, includes readers deployed in fixed locations in the facility. Each of the readers is configured to transmit a first signal and to detect from a distance a second signal, which is generated at an RFID transponder embedded in a denture in response to receiving the first signal by backscattering a part of the first signal. The second signal contains information related to the denture, including an identification of the denture owner. The RFID system also includes a first server located within the facility. The first server is configured to communicate with the readers over a network in the facility and to control operations of the readers. Each of the readers sends the information related to the denture to the first server when it detects the second signal from the RFID transponder.

Abstract: The present invention relates to orthodontic positioning appliances that represent teeth in desired positions and related systems and methods. An appliance can include teeth receiving cavities shaped to receive and apply a resilient positioning force to a patient's teeth. An appliance can include an outer component having a surface representing teeth in desired positions. An outer component can be integral with an appliance. An outer component can be separate and configured to couple with an appliance main body.

Abstract: A subject of the invention relates to providing a powder for a translucent zirconia sintered body which is necessary for the production of a zirconia sintered body having a high sintered-body density and high strength and giving an excellent sense of translucency, without conducting any special sintering, such as HIP sintering. The invention relates to a technique for obtaining, through normal-pressure sintering, a translucent zirconia sintered body characterized by comprising zirconia which contains 2-4 mol % yttria as a stabilizer and has an alumina content of 0.2 wt % or lower, and by having a relative density of 99.8% or higher and a total light transmittance, as measured at a thickness of 1.0 mm, of 35% or higher. It is preferred that a powder containing 0-0.2 wt % alumina with a particle diameter of 0.01-0.5 ?m, having a BET specific surface area of 5-16 m2/g and an average particle diameter of 0.3-0.7 ?m, and having a rate of sintering shrinkage in normal-pressure sintering (??/?T; g/cm3·° C.) of 0.

Abstract: The invention provides apparatus and processes for non-load bearing endosteal implants and specifically to an implant tack for mitigating effects of bone resorption and atrophy due to lost or extracted teeth in the maxilla and/or mandible.

Abstract: A dental component comprising a modified porcelain veneering coating thereon is provided, wherein the porcelain veneering coating can comprise a plurality of crystalline inclusions. The crystalline inclusions can serve to strengthen the porcelain veneering coating and the dental component as a whole. A method for the preparation of such treated implants is also provided, the method involving providing a dental component; applying a porcelain slurry comprising about 5% or more by weight of an additive capable of forming a crystalline silicate phase to at least a portion of the surface of the dental component to give a coated dental component; and firing the porcelain-coated dental component.

Abstract: Dental prostheses and methods for making them are disclosed. In one embodiment, a method comprises a sequence of steps including milling a cavity in a block of a coping material, filling the cavity with a green ceramic material, milling a portion of the green ceramic material away to leave a layer of green ceramic material on an occlusal surface formed in the coping material, milling the underside of the block of coping material to form the coping with green ceramic material, and sintering the coping with green ceramic material to complete the prosthesis. The milling steps may be performed by a computer-controlled mill. The computer may execute a CAD-CAM program that includes data from a three dimensional model of a tooth that is to receive the prosthesis. The dental prosthesis may be a dental crown or a dental bridge.

Abstract: A system and method for making a layered dental appliance. The system can include a first mold comprising a negative of a first layer of a layered dental appliance, a second mold comprising a negative of a second layer, and a dental core dimensioned to be at least partially received in the first mold and the second mold. The method can include positioning a first slurry in the first mold, and pressing the dental core into the first slurry to form a first article comprising the dental core and a first layer formed from the first slurry. The method can further include removing the first article from the first mold, positioning a second slurry in the second mold, and pressing the first article into the second slurry to form a second article comprising the dental core, the first layer, and a second layer formed from the second slurry.

Abstract: Various methods and systems are provided for multifunctional denture systems. In one example, among others, a multifunctional oral prosthetic system includes an oral prosthetic device that may be located in an oral cavity. The oral prosthetic device includes a plurality of sensors and an internal module in communication with the plurality of sensors. The internal module is configured to provide sensor data corresponding to at least one of the plurality of sensors to an external processing unit when located in an oral cavity.

Abstract: A device for inserting a threaded dental implant (I) in a patients jawbone as well as for loosening and removing a threaded dental implant (I) mounted and possibly osseointegrated in the alveolus jaw-bone of a patient. An ultrasonic vibration actuator, e.g. a piezoelectric transducer, generates ultrasonic vibrations with a frequency within the range 20-50 kHz, preferably within 24-36 kHz, and preferably in a direction around the longitudinal axis of the dental implant (I). The actuator, being a handpiece (H) structurally connected with a handpiece head (HD). A fitting-means (F), e.g. a socket, is positioned in the head (HD) of the handpiece (H), the head (HD) being arranged for entering the patient's mouth. The fitting-means (F) is shaped to provide a rigid engagement directly with the dental implant (II, I2) or indirectly by an adaptor (AD1, AD2) being rigidly tightened on top of the dental implant (II, I2) platform.

Abstract: A method for forming at least a tooth root in a tooth containing a tooth crown, including: forming a culture core containing the tooth and a cell-containing base material, the tooth being wrapped with the cell-containing base material, and culturing the culture core in a medium to form at least the tooth root in the tooth contained therein, wherein the cell-containing base material contains at least one kind of cells selected from periodontal ligament-derived cells, bone marrow-derived cells, dental follicle-derived cells, dental pulp-derived cells and dental papilla-derived cells, and the medium contains a component contained in a conditioned medium of a serum-free-cultured cell line of a human uterocervical squamous carcinoma cell line; an additive containing at least one selected from IL-1?, IL-6, IL-8, IL-9, EGF, IGF-I, GH, PDGF-AB, VEGF, LIF, HGF, FGF-2, FGF-1, BMP-2, BMP-4, M-CSF, dexamethasone, insulin, thyroxine, thyrocalcitonin, ascorbic acid and ?-glycerophosphate; or both of them.

Abstract: This invention relates to a composite material for biomedical applications, in particular dental applications, which possesses self-healing capacity and is able to incorporate a system for the release of active ingredients at the stage of application and use.

Abstract: A method for manufacturing an inner structure as an insertion geometry and/or as a rotation lock of a ceramic implant or of a ceramic attachment element. Thereby, a rotating disc for removing ceramic material is advanced in an advance direction of the rotating disc perpendicular to the rotation axis of the disc, into a proximally accessible surface of the ceramic implant or into an end surface of a ceramic attachment element.

Abstract: The present embodiments relate to health monitoring systems and, in certain embodiments, to take-home monitoring systems designed for oral appliance monitoring. Embodiments include a method for obtaining data from an oral appliance. The method comprises placing an oral appliance comprising embedded electronics in an oral cavity, wherein the embedded electronics collect data; transmitting the data to a reader, wherein the reader comprises a computer, tablet computer, smart device, reader box, relay transmitter, or a combination thereof.

Abstract: A system and method for making a layered dental appliance. The system can include a mold comprising a negative of an outer shape of a layered dental appliance, and a dental core dimensioned to be at least partially received in the mold. The method can include positioning a first slurry in the mold, and pressing the dental core into the first slurry in the mold to form a first article comprising the dental core and a first layer formed from the first slurry. The method can further include removing the first article from the mold, and firing the first article. The method can further include positioning a second slurry in the mold, and pressing the first article into the second slurry in the mold to form a second article comprising the dental core, the first layer, and a second layer formed from the second slurry.

Abstract: Herein are provided methods, systems, computer-readable media, techniques and processes for adjusting dental prostheses based on soft tissue. These include allowing an operator to define the surface of a dental prosthesis, such as an abutment, that is proximal to the patient's gum relative to a 3D scan of the patient's gums. The operator can define the offset of that surface as well as the limits of that surface.

Abstract: An apparatus for the detection of dental caries on the surface of a remaining tooth present underneath a crown are provided. Such an inventive concept involves the utilization of a proper electrically conductive pathway from the crown exterior to the tooth itself, allowing for impedance measurements to be undertaken to determine the degree of potential demineralization within the tooth and/or adhesive loss at the tooth/crown interface, all due to decay attributable to dental caries or like problems. A measuring electrode may be applied to a specific point on the target crown as well as on the adjacent gum, to measure impedance levels for any appreciable decreases which would indicate underlying tooth decay has been initiated. From that point, the dental professional may undertake proper therapeutic measures to treat such tooth locations in order to avoid far more expensive repairs, such as the implementation of bridges or implants.

Abstract: A biocompatible material, wherein at least a part of a surface of the biocompatible material is characterized by a micro or nano-meter scale topographical structure comprising a plurality of features where the structure is selected to promote the growth of undifferentiated pluripotent stem cells or serve to promote the uniform differentiated growth of stem cells. Furthermore, a biocompatible material is provided having a surface structure and composition that affects a cellular function, in particular cellular functions related to gene induction, cell differentiation and the formation of bone tissue in vivo and ex-vivo.

Abstract: Presented herein are methods and devices for designing dental components, such as physical models of a patient's anatomy, crowns and bridges. An operator of a prosthetic designing system can receive information, such as from a scanner, which provides information on the topology of the patient's dentition. The operator can use this information to design a custom prosthetic to fit the patient. Part of the designing process involves using a finish line defined for a preparation as a segmentation line for a physical die corresponding to the preparation, and using a path of draw line as an insertion axis line for a dental prosthetic.

Abstract: An appliance fabricated to improve the appearance of a patient's smile includes a plurality of simulated teeth. The interior surfaces of each of the teeth closely fits and conforms to the surface of a patient's real teeth while the outer surfaces of each of the simulated teeth has an ideal surface configuration. The dental appliance provides the patient with the appearance of a perfect set of teeth and an ideal smile without a need to alter the dental structure of the patient's teeth.

Abstract: The present invention relates to a material for dental products comprising a mixture of at least one polymerizable monomer and at least one polymer based on polysulfones which is preswollen in a portion of the polymerizable monomer.

Abstract: The present invention relates to a recording medium a method and an apparatus for generating virtual teeth and recording media storing a program performing the method. According to an embodiment of the present invention, a method for generating virtual teeth includes (a) acquiring a tooth image having three-dimensional information from teeth including a damaged tooth; (b) determining an image of a virtual tooth to be inserted into a position of the damaged tooth in a tooth image library having predetermined three-dimensional information and inserting the determined virtual tooth image into the acquired tooth image; and (c) modifying the virtual tooth image by considering tooth images positioned at upper and lower sides or right and left sides of the virtual tooth image. According to the embodiment of the present invention, it is possible to produce a prosthesis most suitable for the state of patient's teeth only once and an operator can minimize post-processing of the produced prosthesis.

Abstract: Implants for forming a positive connection with human or animal parts include a material, such as thermoplastics and thixotropic materials, that can be liquefied by means of mechanical energy. The implants are brought into contact with the tissue part, are subjected to the action of ultrasonic energy while being pressed against the tissue part. The liquefiable material liquefies and is pressed into openings or surface asperities of the tissue part so that, once solidified, the implant is positively joined thereto. The implantation involves the use of an implantation device that includes a generator, an oscillating element, and a resonator. The generator causes the oscillating element to mechanically oscillate, and the element transmits the oscillations to the resonator. The resonator is used to press the implant against the tissue part to transmit oscillations to the implant.

Abstract: Embodiments described herein are related to fillers that are placed within an extraction site in need of bone augmentation and preservation. The fillers encourage sufficient new bone growth in order that normal jaw bone deterioration following tooth removal is prevented. The fillers create, arrange, and assemble an ideal growth environment for new bone growth to rapidly grow and preserve the original contours of an individual's jaw bone. Further embodiments described herein are related to dental implants that are arranged to provide a scaffold upon which a damaged or missing dental papilla may regrow. The dental implants may include a micro-pattern to facilitate directional cell growth.

Abstract: An apparatus and method for the detection of dental caries on the surface of a remaining tooth present underneath a crown are provided. Such an inventive concept involves the utilization of a proper electrically conductive pathway from the crown exterior to the tooth itself, allowing for impedance measurements to be undertaken to determine the degree of potential demineralization within the tooth and/or adhesive loss at the tooth/crown interface, all due to decay attributable to dental caries or like problems. In such a manner, a measuring electrode may be applied to a specific point on the target crown as well as on the adjacent gum, to measure impedance levels for any appreciable decreases which would indicate underlying tooth decay exists. The dental professional may then undertake proper therapeutic measures to treat such tooth locations in order to avoid far more expensive repairs, such as the implementation of bridges or implants.

Abstract: Unlike conventional dental ceramic powder made by grinding, dental ceramic nanocrystals are formed by vaporization into individual particles. Tetragonal zirconia particles thus formed are not broken into pieces, and so do not transform to weaker monoclinic zirconia and weaker sintered products. The particles created by this approach can be much smaller, and dental prostheses sintered from this powder can be stronger and more realistic. For instance, the smaller size of sintered tetragonal zirconia crystals increases optical translucence by reducing scattering from birefringence, and the small average particle size and tight distribution of sizes and shapes can essentially eliminate pores in a sintered product. Cylindrical and spherical particles can be manufactured by this approach, whereas prior art dental ceramic particles were generally neither.

Abstract: Embodiments are provided for accurately characterizing a tooth's movement. One method embodiment includes associating an abnormal tooth shape with a model tooth shape from a reference library of model tooth shapes, mapping a predefined dental reference from the model tooth shape onto at least a portion of the abnormal tooth shape, and adding a location of the predefined dental reference to the abnormal tooth shape based on the mapped predefined dental reference from the model tooth shape.

Abstract: Dental articles are produced using relatively low sintering temperatures to achieve high density dental articles exhibiting strengths equal to and greater than about 700 MPa. Ceramic powders comprised of nanoparticulate crystallites are used to manufacture dental articles. The ceramic powders may include sintering agents, binders and other similar additives to aid in the processing of the ceramic powder into a dental article. The ceramic powders may be processed into dental articles using various methods including, but not limited to, injection molding, gel-casting, slip casting, or electroforming, hand, cad/camming and other various rapid prototyping methods. The ceramic powder may be formed into a suspension, pellet, feedstock material or a pre-sintered blank prior to forming into the dental article.

Abstract: Fastening screws for prosthetic components are provided with a thread achieved by a rolling process (thread rolling). These fastening screw are connected to the fitted screw of universal trunnion CM, angled universal trunnion CM, angled conic mini pillar CM over the dental implant CM (Morse Cone system) intraorally placed. The screw can be used in a variety of prosthetic components line for CM dental implants (Morse Cone system) and other implants lines (outer hexagon, inner hexagon, etc.). The screw made by the rolled thread process provides stronger screws that can be used to fasten prosthetic components onto various dental implants.

Abstract: A system for a dental superstructure to be attached to an implant using a digital model description of a shape of the superstructure, the superstructure including first and second elements. The system comprises a computing device arranged to (a) analyze a recorded real clinical situation or shaped clinical situation of an implant axis and insertion axis, (b) compute a shape of the dental superstructure based at least in part on the determined implant axis, (c) generate digital data representing the shape of the superstructure, and (d) separate the computed shape into first digital data representing a shape of the first element to be connected to the implant and second digital data representing a shape of the second element to be connected to the first element, the shape of the first element being optimized, at least in part, based on a tilt angle between the determined implant axis and insertion axis.

Abstract: A dental prosthesis removal tool comprising a handle portion and a top portion, the top portion including a head portion and a beak portion. The beak portion is configured to engage both a maxillary dental prosthesis and a mandibular dental prosthesis without the tool needing to be reoriented. The dental prosthesis removal tool makes it possible for a dental prosthesis wearer to remove dental prostheses without the user placing his or her fingers inside of his or her mouth. The dental prosthesis removal tool also allows a denture wearer to remove dental prosthesis without bending, work hardening, or breaking metal clasps contained in some dental prostheses. The dental prosthesis removal tool further allows a denture wearer to more comfortably remove his or her dental prosthesis, promoting better patient compliance with maintenance procedures and oral hygiene.

Abstract: Systems and methods are disclosed for intra-oral delivery of drugs.

Abstract: It is intended to provide artificial teeth designed to easily enable bilateral balanced occlusion with less grinding adjustment. According to the present invention, angles formed by occlusal facets of the artificial teeth with an occlusal plane are suitably set. An artificial tooth for maxillary central incisor, for example, has a protrusive facet and a retrusive facet on an incisal edge thereof. Of angles formed by the protrusive facet with the occlusal plane, the angle in cross section along a sagittal plane is 22.0° to 25.5°, and the angle in cross section along a coronal plane is 1.5° to 6.5°. Of angles formed by the retrusive facet with the occlusal plane, the angle in cross section along the sagittal plane is 20.5° to 23.0°, and the angle in cross section along the coronal plane is 1.5° to 6.5°.

Abstract: For a resilient mounting of a spider die onto a dental prosthetic suprastructure on a male spider mold, at least one retention element is molded onto a sleeve, and the retention element has a substantially occlusal alignment. The at least one retention element extends across the entire length of the sleeve and has a head having a connecting neck in its cross-section. In this manner, retention undercuts are formed on both sides of the connecting neck. The connecting neck of the at least one retention element is molded at an offset as opposed to the crown line of the sleeve. A spider die is thus created, which has an improved retention with an increased retention force at a smaller installation height.

Abstract: A billet holder comprising a base and a frame is described. The base and frame are connectable, and when connected are relatively moveable between an open configuration when a billet may be inserted or removed from the billet holder and, a closed configuration when a billet is retained within the billet holder. A billet for being retained within a billet holder, said billet having one or more orientation feature, is also described. The billet may have essentially a D-shape. Further described is a method of manufacture of an article from a billet.

Abstract: In implant dentistry, scan templates, also known as scan appliances or radiographic guides, are fabricated according to patients' anatomy, and later on transferred into surgical guides through CT scan, image segmentation, surface reconstruction, CAD modification, and manufacturing. This approach may be also applied to other kinds of surgery. The final manufactured surgical guides can hardly match the actual geometry of the initial scan templates, thus cannot fit well into patients' mouths, which can pose serious risks for surgery. This invention introduces calibration features to design and make a scan template, and accordingly the workflow to perform treatment planning with the template. Calibration features are geometric form features or their patterns. Iterations are utilized to make sure the reconstructed model of a scan template can replicate or match with the calibration features.

Abstract: A device for handling workpieces. The device has a magazine (12) for holding at least one workpiece, and a delivery location (10). The device is retainable in the magazine by a retainer (s) (43) in the delivery location and displaceable to a position in which the workpiece because of its shape releases the retainer (s) so that the workpiece is free for being removed from the magazine. The device may provide for easy handling of workpieces and may be manufactured cost effectively.

Abstract: Method for extracting an implant installed in a bone, which comprises the application of a torque on an extraction tool in order to thread it in the interior of the implant until the implant-bone connection is broken, with the specific feature that the torque is applied in phases. In each phase a torque that is increasingly greater than in the previous phase is applied and the application of torque is then eased. This method brings about a gradual and controlled deformation of the head of the implant, with the result that the extraction tool is inserted more deeply into the implant. As a result, higher breakage torques may be applied without damage being caused to the extraction tool.

Abstract: A composite bio-ceramic dental implant and fabricating method thereof are disclosed. The composite bio-ceramic is sintered at a temperature between 1000 and 1800° C. using the nearly inert bio-ceramic powder and the active bio-ceramic powder or the completely resorbable bio-ceramic powder. The bioactive bio-ceramic material is dispersed in the inert bio-ceramic material. Therefore, the composite bio-ceramic has enough mechanical strength and good bioactivity for dental implant.

Abstract: The invention provides an identification device, which comprises a dental implantation carrier and an information storage element therein. The identification device has good privacy and bio-compatibility. The invention also provides a method for identification by using the device.

Abstract: Disclosed is a computer-implemented method of designing a number of dental restorations for a patient, wherein the method includes: selecting a composed set of teeth including a number of teeth, where the number of teeth are arranged spatially relative to each other forming a high aesthetic composition; applying the composed set of teeth to a virtual three dimensional representation of the patient's present oral situation to obtain an initial set of teeth; optionally modifying one or more parameters of one or more of the teeth in the initial set of teeth to obtain a finalized set of teeth.