Method and arrangement for collecting data for production of replacement dental parts for the human body

• US 5,851,115 A
• Filed: 12/05/1995
• Issued: 12/22/1998
• Est. Priority Date: 12/06/1993
• Status: Expired due to Term

• Current Assignee: Nobel Biocare Services AG (Envista Holdings Corporation)
• Original Assignee: Nobel Biocare AB (Danaher Corporation)
• Inventors: Carlsson, Lennart, Lie, Anders
• Primary Examiner(s): Wilson, John J.
• Application Number:
  US08/495,620
• Time in Patent Office: 1,113 Days
• Field of Search: 433/215, 433/223, 396/324
• US Class Current: 433/215
• CPC Class Codes: A61B 5/0064 Body surface scanning
• CPC Class Codes: A61C 13/0004 Computer-assisted sizing or machining of dental prostheses
• CPC Class Codes: A61C 9/0053 Optical means or methods, e.g. scanning the teeth by a laser or light beam

Abstract

A method and apparatus thereof for collecting control data for the production of replacement dental parts. The method includes the steps of imaging a body area and a replacement part with a single imaging device which is arranged to take a simultaneous picture of the body area from different angles during one exposure. The pictures are developed and scanned with a reading device which generates digitized data of the imaged body area and the replacement part to be applied in that area. The digitized data is transmitted to computer equipment which automatically reproduces the body area and replacement part on a screen. A computer program calculates spacial relations data of surfaces of the body area and replacement part and the data is used as control data in making and fitting the replacement part in the human body.

Claims

1. An apparatus for collecting control data for production of replacement dental parts for the human body comprising:

(a) means for imaging at least one of a body area and replacement part with a single imaging device arranged to take simultaneous pictures of the body area from different angles during one exposure;

(b) means for developing the pictures and scanning them with a reading device;

(c) means for generating digitized data of at least one of the imaged body area and replacement part to be applied in the area from the reading device;

(d) means for transmitting the digitized data to computer equipment which automatically reproduces the body area and replacement part;

(e) means for calculating spacial relations data of surfaces of at least one of the body area and replacement part with a photogrammetric computer program; and

(f) means for using above data as control data in making and fitting the replacement part.

2. The apparatus of claim 1 wherein the means for imaging comprises a camera arranged to take pictures of the mouth cavity at a distance of about 50 to 150 mm, at one of the level of a fixture, down in the jaw, in an unhealed state and at the level of a spacer, in a healed state, with only spacers protruding above the healed jaw bone.

3. The apparatus of claim 2 wherein the camera comprises at least two virtual lens arranged at a predetermined distance from each other whereby a reduced number of pictures with actual lens functions are used to determine to position of body areas.

4. A method for collecting control data for production of replacement dental parts for the human body comprising the steps of:

(a) imaging at least one of a body area and replacement part with a single imaging device arranged to take simultaneous pictures of the body area from different angles during one exposure;

(b) developing the pictures and scanning them with a reading device;

(c) generating digitized data of at least one of the imaged body area and replacement part to be applied in the area from the reading device;

(d) transmitting the digitized data to computer equipment which automatically reproduces the body area and replacement part;

(e) calculating spacial relations data of surfaces of at least one of the body area and replacement part with a photogrammetric computer program; and

(f) using above data as control data in making and fitting the replacement part.

5. The method of claim 4 wherein the body area comprises mucous membrane in the mouth cavity whereby topography of the mucous membrane is reproduced.

6. The method of claim 4 further comprising the steps of,

placing reference markings on at least one of the body area and replacement part;

and

comparing the simultaneous pictures with respect to the reference markings to identify surfaces of at least one of the body area and replacement part.

7. The method of claim 6 wherein the reference markings have substantially circular shapes.

8. The method of claim 6 further comprising the step of placing no more than three reference markings around the periphery of at least one of the body area and replacement part to determine the center of the body area and replacement part.

9. The method of claim 4 wherein step (e) further comprises determining an inclination of at least one of the body are and replacement part with a surface normal in the form of a three-dimensional vector whose length substantial corresponds to a length of a radius of the body area and replacement part.

10. The method of claim 4 wherein step (e) further comprises determining a solid angle for an end of at least one of the body area and replacement part, said solid angle is determined with a precision of an order of magnitude of 0.01 radians.

11. The method of claim 4 wherein step (e) further comprises determining the position of individual points on at least one of the body area and replacement part, the precision of determining a point on the body area and replacement part is of the order of magnitude of 0.02 mm.