A device for disinfecting and/or sterilization of a dental cavity includes: an electrode pair that extends into the cavity to provide current along a portion of the cavity; and a controller that sends controlled electrical energy to the cavity via current flowing between the electrodes when located in the cavity, thereby to provide electrical energy for disinfection and/or sterilization.

A spacer for an endodontic instrument includes a base surface with a diameter d.sub.G, a top surface with a diameter d.sub.D, which is smaller than the diameter d.sub.G, an axis of rotation, a lateral surface, a height h, an opening with a longitudinal axis for receiving an endodontic instrument and a cylindrical recess for receiving a stopper on the base surface. The spacer is frustoconically formed, and the opening extends from the base surface to the top surface. The longitudinal axis of the opening is coaxial to the axis of rotation of the spacer, and the cylindrical recess is coaxial to the opening.

A spacer for an endodontic instrument includes a base surface with a diameter d.sub.G, a top surface with a diameter d.sub.D, which is smaller than the diameter d.sub.G, an axis of rotation, a lateral surface, a height h, an opening with a longitudinal axis for receiving an endodontic instrument and a cylindrical recess for receiving a stopper on the base surface. The spacer is frustoconically formed, and the opening extends from the base surface to the top surface. The longitudinal axis of the opening is coaxial to the axis of rotation of the spacer, and the cylindrical recess is coaxial to the opening.

In a medical system, a medical device includes a first display that displays a figure or a character corresponding to data relevant to medical treatment performed in the medical device, and a first controller that causes the first display to display the figure or the character corresponding to the data and that, when the data satisfies conditions for notification of a warning, causes the medical device to emit a first warning. A remote control device includes a second display that displays the figure or the character corresponding to the data, and a second controller that causes the second display to display the figure or the character corresponding to the data and that, when the data satisfies the conditions for notification of the warning, causes the remote control device to emit a second warning that is different than the first warning.

In a medical system, a medical device includes a first display that displays a figure or a character corresponding to data relevant to medical treatment performed in the medical device, and a first controller that causes the first display to display the figure or the character corresponding to the data and that, when the data satisfies conditions for notification of a warning, causes the medical device to emit a first warning. A remote control device includes a second display that displays the figure or the character corresponding to the data, and a second controller that causes the second display to display the figure or the character corresponding to the data and that, when the data satisfies the conditions for notification of the warning, causes the remote control device to emit a second warning that is different than the first warning.

A processing device receives, from an image capture device associated with an augmented reality (AR) display, a plurality of images of a face of a patient. The processing device selects a subset of the plurality of images that meet one or more image selection criteria. The selection comprises determining, from the plurality of images, a first image that represents a first position extreme for the face; determining, from the plurality of images, a second image that represents a second position extreme of the face; selecting the first image; and selecting the second image. The processing device further generates a model of a jaw of the patient based at least in part on the subset of the plurality of images that have been selected.

A processing device receives, from an image capture device associated with an augmented reality (AR) display, a plurality of images of a face of a patient. The processing device selects a subset of the plurality of images that meet one or more image selection criteria. The selection comprises determining, from the plurality of images, a first image that represents a first position extreme for the face; determining, from the plurality of images, a second image that represents a second position extreme of the face; selecting the first image; and selecting the second image. The processing device further generates a model of a jaw of the patient based at least in part on the subset of the plurality of images that have been selected.

A dental drill system with electrical-impedance sensing indicates when a bit of the drill system approaches cortical-cancellous bone, or bone-soft tissue interfaces. The drill system has a dental drill handset having a cannula bearing electrically coupled to a drilling bit, the drilling bit having an electrically insulated portion and an exposed portion. The cannula bearing is coupled to an electrical impedance spectroscopy sensing device configured to measure impedance between the cannula bearing of the dental drill handset and a ground plate, and a processing system uses EIS measurements to distinguish when the bit of the drill system approaches cortical- or cancellous bone, or bone-soft tissue interfaces.

A dental drill system with electrical-impedance sensing indicates when a bit of the drill system approaches cortical-cancellous bone, or bone-soft tissue interfaces. The drill system has a dental drill handset having a cannula bearing electrically coupled to a drilling bit, the drilling bit having an electrically insulated portion and an exposed portion. The cannula bearing is coupled to an electrical impedance spectroscopy sensing device configured to measure impedance between the cannula bearing of the dental drill handset and a ground plate, and a processing system uses EIS measurements to distinguish when the bit of the drill system approaches cortical- or cancellous bone, or bone-soft tissue interfaces.

A dental tool includes: a hand piece; an endodontic hand file; a stopper, wherein the stopper comprises a first hole for receiving a portion of the endodontic hand file; and a mechanical motion module that imparts mechanical motion to the endodontic hand file. A dental system includes: a hand piece; an endodontic file; and a stopper comprising at least two holes, wherein a first hole receives a portion of the endodontic file, and wherein a second hole receives a portion of a first tube for delivering a liquid to the endodontic file. The dental system can further include a second tube partially contained in a third hole of the stopper for suctioning liquids from a patient's mouth. The dental system can also further include a mechanical motion module.