Method and arrangement for cleaning of a canal

Patent metadata

Field	Value
Publication number	US-11638634-B2
Application number	US-201715714409-A
Country	US
Kind code	B2
Filing date	Sep 25, 2017
Priority date	Sep 25, 2017
Publication date	May 2, 2023
Grant date	May 2, 2023

Abstract

The invention relates to a method and an arrangement for the cleaning of a circumferentially closed canal by means of a light guide conducting a laser beam, wherein the entry of the laser beam into the light guide is interrupted when the free end of the light guide is outside of the canal and/or the movement of the light guide within the canal is monitored and if there is no movement or the movement is below a first threshold value then a signal is triggered and/or the laser radiation is turned off or its output is reduced, and wherein the turning off of the laser radiation or its reducing is controlled in dependency of at least one signal change and/or a second threshold and/or a signal change relative to the second threshold determined during at least one course of time starting before and including the entry of the light guide into the canal.

First claim

The invention claimed is:

1. A method for the cleaning of a circumferentially closed canal by means of a light guide conducting a laser beam, comprising:
measuring a position of a free end of the light guide within the canal;
wherein a supply of the laser beam to the light guide is interrupted when the free end of the light guide is moved from inside the canal to outside the canal;
monitoring a movement of the light guide within the canal;
turning off or reducing an output of a laser radiation, responsive to detecting that there is no movement or the movement is below a first threshold value, based on at least one signal change representative of the movement,
wherein a verification of whether the light guide is inside the canal or outside the canal is carried out through a combination of:
a) radiation received by the light guide that is derived from an area surrounding the light guide,
b) through a changing reflection component of a radiation reflected at the free end of the light guide,
c) measurement of a change in impedance via an outer metallization of the light guide,
d) measuring the distance to the nearest object in the vicinity of a fiber tip with time of flight measurement (TOF),
e) measuring the ambient light with a sensor integrated in a TOF chip, and
f) measuring the distance to the nearest object in the vicinity of the fiber tip by ultrasound pulses and
wherein the combination is a combination selected from the group consisting of a)+b), a)+c), b)+c), c)+f), a)+b)+c), c)+d), d)+e), and c)+d)+e),
wherein data of one or several verification methods that detect the entry of the light guide in the canal is recorded over a plurality of time intervals corresponding to a plurality of usages of the light guide and said data is stored to obtain a plurality of time profiles that define at least a normal use and an abnormal use of the light guide, said normal use comprising entering the canal with a fiber of the light guide, moving the fiber up and down the canal and removing the fiber from the canal, and said abnormal use comprising moving the fiber tip towards an eye and,
wherein responsive to obtaining said plurality of time profiles, detecting the abnormal use based on the plurality of time profiles, and either prohibiting switching the laser on or switching the laser off responsive to said laser being already active.

2. A method according to claim 1 , wherein the turning off of the laser radiation or its reducing is controlled in dependency of at least two signal changes and/or two second thresholds different from each other and/or signal changes relative to the two second thresholds determined during at least two courses of time determined in dependency of the entry of the light guide into the canal.

3. A method according to claim 1 , wherein material present on the inside of the canal is removed through laser-induced hydrodynamic fluid movement.

4. A method according to claim 1 , further comprising enhancing bacteria killing with traditional PDT (photodynamic therapy) fluids by using laser induced hydrodynamic fluid motion to agitate these fluids.

Assignees

• Dentsply Sirona Inc

Inventors

• Ertl Thomas
• Diebolder Rolf

Classifications

• A61L2/18

  Liquid substances · CPC title

• A61L2/08

  Radiation · CPC title

• A61N5/067

  using laser light · CPC title

• A61C5/50

  Implements for filling root canals; Methods or instruments for medication of tooth nerve channels · CPC title

• A61C1/0007

  Control devices or systems (fluid temperature control in air and water supply systems of dental machines or apparatus A61C1/0069) · CPC title