Method for making dental coping

Claim 2

In a method for making a fixed precision dental restoration comprising either a fixed crown, coping, inlay, or bridge from an impression of teeth having first been ground to receive a fixed dental restoration constructed of an alloy base metal and on which a tooth simulating porcelain or plastic jacket may be subsequently applied, which method comprises making an artificial stone model of the teeth from the impression; making removable dies from the stone model simulating those teeth that have been ground to receive the fixed dental restoration; making a wax crown pattern having the desired configuration of the dental restoration, to which pattern a sprue is attached for removal of the wax forming the wax crown pattern and which also subsequently serves as a channel by which metal is centrifugally cast into a mold of the wax crown pattern; making a mold of the wax crown pattern; centrifugally casting a chrome cobalt alloy into the cavity defined in the mold; recovering the formed metal configuration; cleaning and polishing the formed metal configuration; and facing with porcelain the portions of those teeth having been ground to receive a plastic or porcelain material; the improvement for casting a single posterior full crown restoration comprising: attaching the sprue to the wax crown pattern at the thickest area of the pattern.

Claim 3

The method of claim 1 further characterized in that said sprue is formed of an essentially straight piece of about 10 gauge round sprue wax approximately 3 mm in length.

Claim 4

In a method for making a fixed precision dental restoration comprising either a fixed crown, coping, inlay, or bridge from an impression of teeth having first been ground to receive a fixed dental restoration constructed of an alloy base metal and on which a tooth simulating porcelain or plastic jacket may be subsequently applied, which method comprises making an artificial stone model of the teeth from the impression; making removable dies from the stone model simulating those teeth that have been ground to receive the fixed dental restoration; making a wax crown pattern having the desired configuration of the dental restoration, to which pattern a sprue is attached for removal of the wax forming the wax crown pattern and which also subsequently serves as a channel by which metal is centrifugally cast into a mold of the wax crown pattern; making a mold of the wax crown pattern; centrifugally casting a chrome cobalt alloy into the cavity defined in the mold; recovering the formed metal configuration; cleaning and polishing the formed metal configuration; and facing with porcelain the portions of those teeth having been ground to receive a plastic or porcelain material; the improvement for casting inlays and 3/4 crowns comprising attaching a sprue formed into a loop to the wax crown pattern at the thickest area of the pattern.

Claim 5

In a method for making a fixed precision dental restoration comprising either a fixed crown, coping, inlay, or bridge from an impression of teeth having first been ground to receive a fixed dental restoration constructed of an alloy base metal and on which a tooth simulating porcelain or plastic jacket may be subsequently applied, which method comprises making an artificial stone model of the teeth from the impression; making removable dies from the stone model simulating those teeth that have been ground to receive the fixed dental restoration; making a wax crown pattern having the desired configuration of the dental restoration, to which pattern a sprue is attached for removal of the wax forming the wax crown pattern and which also subsequently serves as a channel by which metal is centrifugally cast into a mold of the wax crown pattern; making a mold of the wax crown pattern; centrifugally casting a chrome cobalt alloy into the cavity defined in the mold; recovering the formed metal configuration; cleaning and polishing the formed metal configuration; and facing with porcelain the portions of those teeth having been ground to receive a plastic or porcelain material; the improvement for casting inlays and 3/4 crowns comprising attaching a sprue formed into a loop to the wax crown pattern at the thickest area of the pattern.

Claim 6

The method of claim 1 further characterized in that said sprue is formed into a 360* horizontal loop of about 10 gauge to about 14 gauge round sprue wax of less than about 12 mm in length.

Claim 7

In a method for making a fixed precision dental restoration comprising either a fixed crown, coping, inlay, or bRidge from an impression of teeth having first been ground to receive a fixed dental restoration constructed of an alloy base metal and on which a tooth simulating porcelain or plastic jacket may be subsequently applied, which method comprises making an artificial stone model of the teeth from the impression; making removable dies from the stone model simulating those teeth that have been ground to receive the fixed dental restoration; making a wax crown pattern having the desired configuration of the dental restoration, to which pattern a sprue is attached for removal of the wax forming the wax crown pattern and which also subsequently serves as a channel by which metal is centrifugally cast into a mold of the wax crown pattern; making a mold of the wax crown pattern; centrifugally casting a chrome cobalt alloy into the cavity defined in the mold; recovering the formed metal configuration; cleaning and polishing the formed metal configuration; and facing with porcelain the portions of those teeth having been ground to receive a plastic or porcelain material; the improvement for casting a porcelain fired on cobalt coping comprising attaching a sprue formed into a loop to the apex of the labial lingual planes when casting a single anterior crown and to the apex of the lingual occlusal when casting a single posterior crown, equidistant from the mesial to the distal at the incisal edge at an inclination of about 45* to the occlusal plane.

Claim 8

In a method for making a fixed precision dental restoration comprising either a fixed crown, coping, inlay, or bRidge from an impression of teeth having first been ground to receive a fixed dental restoration constructed of an alloy base metal and on which a tooth simulating porcelain or plastic jacket may be subsequently applied, which method comprises making an artificial stone model of the teeth from the impression; making removable dies from the stone model simulating those teeth that have been ground to receive the fixed dental restoration; making a wax crown pattern having the desired configuration of the dental restoration, to which pattern a sprue is attached for removal of the wax forming the wax crown pattern and which also subsequently serves as a channel by which metal is centrifugally cast into a mold of the wax crown pattern; making a mold of the wax crown pattern; centrifugally casting a chrome cobalt alloy into the cavity defined in the mold; recovering the formed metal configuration; cleaning and polishing the formed metal configuration; and facing with porcelain the portions of those teeth having been ground to receive a plastic or porcelain material; the improvement for casting a porcelain fired on cobalt coping comprising attaching a sprue formed into a loop to the apex of the labial lingual planes when casting a single anterior crown and to the apex of the lingual occlusal when casting a single posterior crown, equidistant from the mesial to the distal at the incisal edge at an inclination of about 45* to the occlusal plane.

Claim 9

The method of claim 5 further characterized in that said sprue is formed into a horizontal loop of about 360*.

Claim 10

In a method for making a fixed precision dental restoration comprising either a fixed crown, coping, inlay, or bridge from an impression of teeth having first been ground to receive a fixed dental restoration constructed of an alloy base metal and on which a tooth simulating porcelain or plastic jacket may be subsequently applied, which method comprises making an artifical stone model of the teeth from the impression; making removable dies from the stone model simulating those teeth that have been ground to receive the fixed dental resotration; making a wax crown pattern having the desired configuration of the dental restoration, to which pattern a sprue is attached for removal of the wax forming the wax crown pattern and which also subsequently serves as a channel by which metal is centrifugally cast into a mold of the wax crown pattern; making a mold of the wax crown pattern; centrifugally casting a chrome cobalt alloy into the cavity defined in the mold; recovering the formed metal configuration; cleaning and polishing the formed metal configuration; and facing with porcelain the portions of those teeth having been ground to receive a plastic or porcelain material; the improvement for casting multiple unit restorations including abutments and pontics, full coverage porcelain veener or thermoplastic, or porcelain labail buccal veener, by attaching a multiple of final lead, base feed, and primary lead sprues to said unit restorations, which in the case of anterior abutment or pontic copings, the final lead sprue is attached at the incisal apex with about a 20 degree lingual inclination, and in the case of posterior units of either the full coverage or cast occlusal type, the final lead sprue is attached at the intersection of the lingual occlusal planes with about a 45 degree lingual inclination, being equidistant from the mesial distal segments; the lingually inclined ends of the final lead sprues being tied together with a single length of base feed sprue wax formed in a straight or arched line essentially parallel to the longitudinal geometry of the bridge and positioned essentially at right angles to each individual final lead; the primary leads being connected to the base feed sprue at essentially its mid-point, between the final leads, forming an arch and a convergence at a point approximately at the center of the work, from the lingual aspect, the primary leads forming a juncture with the base feed line at essentially a 90 degree angle; the primary leads being thereafter sealed together, the work lifted from the model, contact points built out, and then sealed to an appropriate sprue former constructed in a circular design with an extended portion protruding downward in the investment assembly, the sprue former being attached at the apex of its extended portion to the sprue of the wax pattern.

Claim 11

In a method for making a fixed precision dental restoration comprising either a fixed crown, coping, inlay, or bridge from an impression of teeth having first been ground to receive a fixed dental restoration constructed of an alloy base metal and on which a tooth simulating porcelain or plastic jacket may be subsequently applied, which method comprises making an artifical stone model of the teeth from the impression; making removable dies from the stone model simulating those teeth that have been ground to receive the fixed dental resotration; making a wax crown pattern having the desired configuration of the dental restoration, to which pattern a sprue is attached for removal of the wax forming the wax crown pattern and which also subsequently serves as a channel by which metal is centrifugally cast into a mold of the wax crown pattern; making a mold of the wax crown pattern; centrifugally casting a chrome cobalt alloy into the cavity defined in the mold; recovering the formed metal configuration; cleaning and polishing the formed metal configuration; and facing with porcelain the portions of those teeth having been ground to receive a plastic or porcelain material; the improvement for casting multiple unit restorations including abutments and pontics, full coverage porcelain veener or thermoplastic, or porcelain labail buccal veener, by attaching a multiple of final lead, base feed, and primary lead sprues to said unit restorations, which in the case of anterior abutment or pontic copings, the final lead sprue is attached at the incisal apex with about a 20 degree lingual inclination, and in the case of posterior units of either the full coverage or cast occlusal type, the final lead sprue is attached at the intersection of the lingual occlusal planes with about a 45 degree lingual inclination, being equidistant from the mesial distal segments; the lingually inclined ends of the final lead sprues being tied together with a single length of base feed sprue wax formed in a straight or arched line essentially parallel to the longitudinal geometry of the bridge and positioned essentially at right angles to each individual final lead; the primary leads being connected to the base feed sprue at essentially its mid-point, between the final leads, forming an arch and a convergence at a point approximately at the center of the work, from the lingual aspect, the primary leads forming a juncture with the base feed line at essentially a 90 degree angle; the primary leads being thereafter sealed together, the work lifted from the model, contact points built out, and then sealed to an appropriate sprue former constructed in a circular design with an extended portion protruding downward in the investment assembly, the sprue former being attached at the apex of its extended portion to the sprue of the wax pattern.

Claim 12

The method of claim 7 further characterized in that when said multiple unit restoration is a two unit casting, a single primary lead is employed with the total distance from the casting surface to the top of the sprue cone should be from about 10 to 13 mm.

Claim 13

In a method for making a fixed precision dental restoration comprising either a fixed crown, coping, inlay, or bridge from an impression of teeth having first been ground to receive a fixed dental restoration constructed of an alloy base metal and on which a tooth simulating porcelain or plastic jacket may be subsequently applied, which method comprises making an artificial stone model of the teeth from the impression; making removable dies from the stone model simulating those teeth that have been ground to receive the fixed dental restoration; making a wax crown pattern having the desired configuration of the dental restoration, to which pattern a sprue is attached for removal of the wax forming the wax crown pattern and which also subsequently serves as a channel by which metal is centrifugally cast into a mold of the wax crown pattern; making a mold of the wax crown pattern; centrifugally casting a chrome cobalt alloy into the cavity defined in the mold; recovering the formed metal configuration; cleaning and polishing the formed metal configuration; and facing with porcelain the portions of those teeth having been ground to receive a plastic or porcelain material; the improvement which comprises making said mold of the wax crown pattern out of a phosphate bound silica investment material.

Claim 14

In a method for making a fixed precision dental restoration comprising either a fixed crown, coping, inlay, or bridge from an impression of teeth having first been ground to receive a fixed dental restoration constructed of an alloy base metal and on which a tooth simulating porcelain or plastic jacket may be subsequently applied, which method comprises making an artificial stone model of the teeth from the impression; making removable dies from the stone model simulating those teeth that have been ground to receive the fixed dental restoration; making a wax crown pattern having the desired configuration of the dental restoration, to which pattern a sprue is attached for removal of the wax forming the wax crown pattern and which also subsequently serves as a channel by which metal is centrifugally cast into a mold of the wax crown pattern; making a mold of the wax crown pattern; centrifugally casting a chrome cobalt alloy into the cavity defined in the mold; recovering the formed metal configuration; cleaning and polishing the formed metal configuration; and facing with porcelain the portions of those teeth having been ground to receive a plastic or porcelain material; the improvement which comprises making said mold of the wax crown pattern out of a phosphate bound silica investment material.

Claim 15

The method of claim 9 further characterized in that said phosphate bound silica mold is heated to a temperature within the range of from about 1,450* F to about 1,800* F.