3M INNOVATIVE PROPERTIES COMPANY

Patent Trials and Appeals BoardNov 1, 2021

2021000107 (P.T.A.B. Nov. 1, 2021)

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. 15/319,138 12/15/2016 Helmut Mayr 75372US004 9460 32692 7590 11/01/2021 3M INNOVATIVE PROPERTIES COMPANY PO BOX 33427 ST. PAUL, MN 55133-3427 EXAMINER DEHGHAN, QUEENIE S ART UNIT PAPER NUMBER 1741 NOTIFICATION DATE DELIVERY MODE 11/01/2021 ELECTRONIC 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. Notice of the Office communication was sent electronically on above-indicated "Notification Date" to the following e-mail address(es): LegalUSDocketing@mmm.com PTOL-90A (Rev. 04/07) UNITED STATES PATENT AND TRADEMARK OFFICE BEFORE THE PATENT TRIAL AND APPEAL BOARD Ex parte HELMUT MAYR and GALLUS SCHECHNER Appeal 2021-000107 Application 15/319,138 Technology Center 1700 Before TERRY J. OWENS, JEFFREY T. SMITH, and JENNIFER R. GUPTA, Administrative Patent Judges. OWENS, Administrative Patent Judge. DECISION ON APPEAL STATEMENT OF THE CASE Pursuant to 35 U.S.C. § 134(a), the Appellant1 appeals from the Examiner’s decision to reject claims 1–6 and 8–14. We have jurisdiction under 35 U.S.C. § 6(b). We AFFIRM. 1 “Appellant” refers to “applicant” as defined in 37 C.F.R. § 1.42. The Appellant identifies the real party in interest as 3M Company (Appeal Br. 2). Appeal 2021-000107 Application 15/319,138 2 CLAIMED SUBJECT MATTER The claims are directed to a process and kit for producing a sintered lithium disilicate glass ceramic dental restoration. Claim 1, reproduced below, is illustrative of the claimed subject matter: 1. A process for producing a sintered lithium disilicate glass ceramic dental restoration out of a porous 3-dim article, the process comprising: sintering the porous 3-dim article having the shape of a dental restoration with an outer and inner surface to obtain a sintered lithium disilicate ceramic dental restoration, the sintered lithium disilicate glass ceramic dental restoration comprising: Si oxide calculated as SiO2: from 55 to 80 wt.-%; Li oxide calculated as Li2O: from 7 to 16 wt.-%; Al oxide calculated as Al2O3: from 1 to 5 wt.-%; and P oxide calculated as P2O5: from 1 to 5 wt.-%, wt.-% with respect to the weight of the dental restoration, the sintering being done under reduced atmospheric pressure conditions, the reduced atmospheric pressure conditions being applied above a temperature of 600°C. REFERENCES The prior art relied upon by the Examiner is: Name Reference Date Burger US 2010/0248189 A1 Sept. 30, 2010 Ritzberger US 2018/0099899 A1 Apr. 12, 2018 Schechner WO 2008/098157 A1 Aug. 14, 2008 Mayr EP 2 450 000 A1 May 9, 2012 REJECTIONS The claims stand rejected under 35 U.S.C. § 103 as follows: 1) claims 1–4, 8, and 11–14 over Ritzberger in view of Burger; claims 5 and 6 over Ritzberger in view of Burger and Mayr; and claims 9 and 10 over Ritzberger in view of Burger and Schechner. Appeal 2021-000107 Application 15/319,138 3 OPINION The Appellant argues the claims as a group (Appeal Br. 4–5). We therefore limit our discussion to one claim, i.e., claim 1. See 37 C.F.R. § 41.37(c)(1)(iv) (2013). Ritzberger heat treats a lithium silicate glass ceramic dental restoration comprising 66.0–77.0 wt% SiO2, 12.0–20.0 wt% Li2O, 0 to 7.0 (in particular 3.0 to 7.0) wt% P2O5, and 0 to 6.0 (in particular 3.0 to 4.0) wt% Al2O3 at a temperature of 450–780 ºC, preferably 480–500 ºC followed by 650–750 ºC (¶¶ 33, 51, 53, 59–62, 65). The heat treatment can take place during hot pressing, preferably at a pressure of 2–10 bar (¶¶ 64, 66). Ritzberger is silent as to the heat treatment atmospheric pressure. Bulgur sinters a dental restoration facing precursor at a temperature of 700–1100 ºC and a pressure of about 25–50 mbar (¶¶ 28, 45). An exemplary glass ceramic facing precursor formulation “comprises 60% to 70% by weight of silica, 9% to 13% by weight of alumina, 5% to 10% by weight of potassium-oxide, 9% to 13% by weight of sodium-oxide, 0% to 1 % by weight of lithium-oxide, 2% to 5% by weight of calcia, 1 % to 2% by weight of barium-oxide, 0% to 1 % by weight of zirconium oxide and 0% to 1 % cerium-oxide or cerium-fluoride” (¶ 71). The Appellant argues that Ritzberger “teaches the heating step under increased atmospheric pressure, e.g., 2-10 bar (Ritzberger, e.g., paras [0066] and [0090]-[0093]” (Appeal Br.4), and “provides no motivation for modifying the sintering process in any way, let alone motivation to modify the sintering under reduced pressure instead of increased pressure” (id.). Ritzberger’s 2–10 bar is the hot pressing pressure, not the heat treatment atmospheric pressure (¶ 66). Appeal 2021-000107 Application 15/319,138 4 The Appellant argues that “Burger fails to teach a composition consistent with the composition in Ritzberger” (Appeal Br. 4), and “[e]ven if the skilled artisan was motivated to modify the process disclosed in Ritzberger, they would not haven [sic] looked to the process disclosed in Burger with any expectation of success, considering the Burger process is directed toward preparing a different composition” (id.). Burger’s disclosure that the glass ceramic material can be a commercially available glass ceramic material (¶83) would have indicated to one of ordinary skill in the art that Burger’s process is suitable for glass ceramic dental restoration materials generally, including that of Ritzberger. The Appellant argues that “[n]othing in Ritzberger or Burger suggest[s] that the processes would be interchangeable, let alone that either process would be suitable for a composition having self-supporting properties, as presently disclosed” (Appeal Br. 4–5), and that “Burger specifically teaches using a support frame during sintering” (Appeal Br. 5). The rejection does not require Ritzberger’s and Burger’s processes to be interchangeable, the Appellant’s claim 1 does not require self-supporting properties, and Burger does not indicate that use of the facing precursor sintering pressure requires the presence of a facing precursor frame. For the above reasons, we are not persuaded of reversible error in the rejections. CONCLUSION The Examiner’s rejections are affirmed. Appeal 2021-000107 Application 15/319,138 5 DECISION SUMMARY In summary: Claims Rejected 35 U.S.C. § Reference(s)/Basis Affirmed Reversed 1–4, 8, 11– 14 103 Ritzberger, Burger 1–4, 8, 11– 14 5, 6 103 Ritzberger, Burger, Mayr 5, 6 9, 10 103 Ritzberger, Burger, Schechner 9, 10 Overall Outcome 1–6, 8–14 TIME PERIOD FOR RESPONSE No time period for taking any subsequent action in connection with this appeal may be extended under 37 C.F.R. § 1.136(a). See 37 C.F.R. § 1.136(a)(1)(iv). AFFIRMED