Ex Parte WhiteDownload PDFBoard of Patent Appeals and InterferencesAug 22, 201211878337 (B.P.A.I. Aug. 22, 2012) Copy Citation UNITED STATES PATENT AND TRADEMARK OFFICE UNITED STATES DEPARTMENT OF COMMERCE United States Patent and Trademark Office Address: COMMISSIONER FOR PATENTS P.O. Box 1450 Alexandria, Virginia 22313-1450 www.uspto.gov APPLICATION NO. FILING DATE FIRST NAMED INVENTOR ATTORNEY DOCKET NO. CONFIRMATION NO. 11/878,337 07/23/2007 Dennis Joseph White 7817 7590 08/23/2012 Dennis J. White 41 N Main St Cranbury, NJ 08512 EXAMINER SINGH, SUNIL K ART UNIT PAPER NUMBER 3732 MAIL DATE DELIVERY MODE 08/23/2012 PAPER Please find below and/or attached an Office communication concerning this application or proceeding. The time period for reply, if any, is set in the attached communication. PTOL-90A (Rev. 04/07) UNITED STATES PATENT AND TRADEMARK OFFICE __________ BEFORE THE BOARD OF PATENT APPEALS AND INTERFERENCES __________ Ex parte DENNIS JOSEPH WHITE __________ Appeal 2011-011471 Application 11/878,337 Technology Center 3700 __________ Before ERIC GRIMES, LORA M. GREEN, and ERICA A. FRANKLIN, Administrative Patent Judges. GRIMES, Administrative Patent Judge. DECISION ON APPEAL This is an appeal under 35 U.S.C. § 134 involving claims to a method of making a dental cast, which the Examiner has rejected for obviousness. We have jurisdiction under 35 U.S.C. § 6(b). We reverse. STATEMENT OF THE CASE The Specification discloses a method of “making accurate stone dental casts and models, which are used in the process of fabricating removable dental appliances and indirect dental restorations” such as dentures (Spec. 1). Appeal 2011-011471 Application 11/878,337 2 The Specification discloses that coating a dental impression with a stone- setting catalyst, such as dental stone that has set and been ground into a powder, results in a dental cast that more accurately reproduces the original tooth (id. at 12-13, 18). Claims 1, 10, and 11 are on appeal. Claim 1 is representative and reads as follows: 1. An improved method for producing a stone dental cast comprising the steps of: a. placing stone setting catalyst, onto the internal surface of an elastomeric dental impression; b. pouring a wet, mixed dental stone into said elastomeric dental impression and onto said catalyst, whereby the dental stone juxtaposed to said catalyst sets faster, and further whereby, an accurate gypsum cast is formed by a stratified set, thereby, producing accurate restoration or prosthesis. The Examiner has rejected all of the claims on appeal under 35 U.S.C. § 103(a) as obvious based on Eisner 1 and Hamer 2 (Answer 3). The Examiner finds that Eisner discloses “placing a thin layer of dental stone setting catalyst (veneer) onto the internal surface of a dental impression material (column 3, lines 15-18)” and pouring dental stone into the impression; “whereby the dental stone juxtaposed sets faster; wherein the cast is formed by a stratified set (layers) (column 3, lines 23-29)” (id. at 4). The Examiner finds that Hamer “teaches that it is known to use gypsum and elastomeric impression materials to form a dental cast (column 1, lines 15-19)” and concludes that it would have been obvious to modify Eisner’s method to use gypsum as the 1 Eisner, US 4,243,389, issued Jan. 6, 1981. 2 Hamer, US 5,085,811, issued Feb. 4, 1992. Appeal 2011-011471 Application 11/878,337 3 dental stone material and to use an elastomeric dental impression based on Hamer’s teaching (id.). Appellant argues, among other things, that “Eisner does not first place a catalyst before his first pour of stone. Eisner places wet mixed stone . . . [and] wet stone does not share the chemical properties and attributes of a catalyst” (Appeal Br. 17). Appellant also argues that Hamer “places an impression setting catalyst onto the surface of the impression material . . . to remove unwanted hydrogen gas, and thus, form a smoother stone cast. Hamer’s catalyst does not influence the setting of dental stone. He does not apply a stone setting catalyst.” (Id. at 19.) We agree with Appellant that the Examiner has not shown that a method meeting all the limitations of claim 1 would have been obvious to a person of ordinary skill in the art based on Eisner and Hamer. Claim 1 requires two distinct steps: (1) placing stone setting catalyst onto the internal surface of a dental impression, and (2) pouring dental stone into the impression and onto the catalyst (see claim 1). The Specification describes different ways in which the catalyst can be applied to the impression: as powdered dental stone (Spec. 12-13), as a liquid slurry that is allowed to evaporate to leave a thin film coating (id. at 15), or by discarding a first cast and pouring a second cast from the original impression (id. at 16). In each case, however, the Specification describes a catalyst-applying step that is separate from the step of pouring the dental stone into the impression to produce the final cast. Eisner discloses an apparatus for accurately placing a dowel pin in the center of a tooth impression, to allow removal and repeated placement and Appeal 2011-011471 Application 11/878,337 4 fitting of the tooth model during fabrication (Eisner, col. 1, ll. 5-28). Eisner states that its device is used to position an indicator showing where the dowel pin should be placed (id. at col. 3, ll. 2-15) relative to a “dental impression . . . taken in the usual manner” (id. at col. 3, ll. 1-2). Eisner’s process continues as follows: Casting material is subsequently deposited within the impression and subjected to vibration in the usual manner. During such vibration, base 1 is held firmly in place by the impression material and stop 6. Prior to setting of the plaster, dowel pin P, in its holder 7, is set back into place on base member 1 in abutment with indicator 10. Upon setting of the impression deposited dental stone, all components of the present apparatus are removed leaving the partially exposed dowel pin in place. A second pour is then made with the jaw reproduction being removed from the impression after setting of the second pour. Subsequent removal of the tooth model and prosthetic fitting is all thereafter done in the conventional manner. (Id. at col. 3, ll. 15-30.) Hamer discloses that “curable vinyl polysiloxane compositions are used to make negative impressions of teeth, which serve as molds for casting the positive model, the positive model being a cured epoxy or gypsum material” (Hamer, col. 1, ll. 15-19). Hamer discloses that hydrogen gas escaping from the mold can cause pits in the casting material (id. at col. 1, ll. 21-23), and that finely divided palladium can prevent this problem (id. at col. 1, ll. 24-34). Hamer does not disclose any stone-setting catalysts. We agree with Appellant that neither Eisner nor Hamer discloses the first step recited in claim 1: placing a stone-setting catalyst on the internal surface of an impression before pouring dental stone onto it. The Examiner Appeal 2011-011471 Application 11/878,337 5 has not persuasively explained why such a step would have been obvious to a skilled worker despite the references’ silence on this point. The Examiner argues that “the claims are broadly claiming a catalyst in which Eisner discloses a stone that sets. Therefore, the initial layer must inherently have a catalyst that causes or initiates the material to set.” (Answer 5.) The Examiner has not, however, pointed to any evidence showing that dental stone does not set in the absence of a catalyst, and therefore has not shown that a skilled worker would have understood Eisner’s process to require a catalyst. The Examiner also argues that Appellant has not claimed any specific properties/characteristic of the catalyst to differentiate from the prior art. The Appellant[’]s specification states that the catalyst is a dental stone material that is hydrated. The Examiner points out, that the initial dental stone that is poured in the impression material is a paste like substance and therefore must be hydrated in order to have the flowing property of a paste/puddy [sic]. (Answer 5.) As we understand it, the Examiner’s reasoning is that the Specification states that dental stone material that is hydrated is a catalyst and, since Eisner’s process uses wet dental stone, it is also a catalyst. This reasoning is also unpersuasive. The Examiner has pointed to no passage in the Specification to support the position that wet dental stone itself is a catalyst, and our review of the Specification did not reveal one. In addition, as discussed above, claim 1 requires two separate steps: placing a catalyst onto an impression, and then pouring wet dental stone onto the catalyst. The claim does not read on a single step of pouring wet dental stone that is also a catalyst into a dental impression. Appeal 2011-011471 Application 11/878,337 6 Finally, the Examiner argues that “dental stone is a plaster type material and will form a porous layer upon setting. Therefore, once a second layer of plaster is poured on top of the first layer, some of the dental[ ] stone will be seeped into the first porous layer causing the second stone to set at a slower rate.” (Answer 5.) This argument is also unpersuasive. First, the Examiner has pointed to no evidence in the record to show that the asserted effect actually occurs. Second, the Specification describes the effect of a catalyst layer as speeding the hardening of the dental stone in contact with it, not causing subsequently applied stone to set at a slower rate. (See Spec. 13: “Any errant set stone particle from a previous stone mix would detrimentally serve as a catalyst to start the setting of wet dental stone at a site away from the impression surface . . . [and] compete with the desired setting of wet stone juxtaposed to the surface of the impression” (emphasis added).) SUMMARY We reverse the rejection of claims 1, 10, and 11 as obvious based on Eisner and Hamer. REVERSED alw Copy with citationCopy as parenthetical citation