DETAILED ACTION
Status of Application
1. The claims 1-22 and 25 are pending and presented for the examination.
Priority
2. Receipt is acknowledged of certified copies of papers required by 37 CFR 1.55.
Information Disclosure Statement
3. The information disclosure statement (IDS) submitted on 08/23/2023, 07/29/2025, 11/05/2025, and 11/12/2025 are being considered by the examiner.
Claim Rejections - 35 USC § 112
The following is a quotation of 35 U.S.C. 112(b):
(b) CONCLUSION.—The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention.
The following is a quotation of 35 U.S.C. 112 (pre-AIA ), second paragraph:
The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention.
4. Claim 2 is rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor (or for applications subject to pre-AIA 35 U.S.C. 112, the applicant), regards as the invention. The claim limitation of a non-stoichiometric quartz solid solution phase is unclear. It is ambiguous as to which types of crystalline phases this term would cover. The instant Specification defines stoichiometric phases as those having Si:Al ratios of x:y wherein x and y are integers. However, the corresponding non-stoichiometric phases are not so clearly defined. It is unclear if any phase wherein an Si:Al ratio cannot be defined by an x:y integer ratio constitutes a non-stoichiometric phase, or if this term is meant to encompass some other type of phase. Because of these ambiguities, the metes and bounds of claim 2 are indefinite and the claim is rejected under USC 112.
Claim Rejections - 35 USC § 102
5. The following is a quotation of the appropriate paragraphs of 35 U.S.C. 102 that form the basis for the rejections under this section made in this Office action:
A person shall be entitled to a patent unless –
(a)(1) the claimed invention was patented, described in a printed publication, or in public use, on sale, or otherwise available to the public before the effective filing date of the claimed invention.
6. Claims 1-22 and 25 are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Dittmer et al (US 2018/0244563 A1).
Regarding claim 1, Dittmer et al teaches a lithium silicate-wollastonite glass ceramic that comprises 72.7 wt% SiO2, 3.3 wt% Al2O3, and 12.9 wt% Li2O and that has crystalline phases of lithium disilicate, wollastonite, and lithium aluminosilicate (see Table 1, example 29). Said wollastonite and lithium aluminosilicate phases are quartz solid solution phases according to the definitions of the instant Specification. Each limitation of claim 1 is therefore met, and the claim is anticipated by the prior art of record.
Regarding claim 2, Dittmer et al teaches a glass ceramic having a phase LixAlxSi1-x-O2. The variable “x” is not specified to be an integer, and as such this crystalline phase is considered to encompass non-stoichiometric phases as defined by the instant Specification.
Regarding claim 3, the aforementioned Dittmer et al glass ceramic comprises a lithium aluminosilicate crystal phase LixAlxSi1-x-O2.
Regarding claim 4, Dittmer et al does not specify the highest intensity reflection peaks of the two quartz solid solution phases. However, as the phases are equivalent to those described in the instant Specification, these phases would lead to equivalent XRD information and peaks falling within the same angle range as those of the instant Specification and claims. It is well settled that when a claimed composition appears to be substantially the same as a composition disclosed in the prior art, the burden is properly upon the applicant to prove by way of tangible evidence that the prior art composition does not necessarily possess characteristics attributed to the CLAIMED composition. In re Spada, 911 F.2d 705, 15 USPQ2d 1655 (Fed. Circ. 1990); In re Fitzgerald, 619 F.2d 67, 205 USPQ 594 (CCPA 1980); In re Swinehart, 439 F.2d 2109, 169 USPQ 226 (CCPA 1971).
Regarding claim 5, Dittmer et al does not specify the spacing of the highest intensity reflection peaks of the two quartz solid solution phases. However, as the phases are equivalent to those described in the instant Specification, these phases would lead to equivalent XRD information and peaks having the same spacing as those of the instant Specification and claims.
Regarding claim 6, the aforementioned Dittmer et al glass ceramic comprises 72.7 wt% SiO2.
Regarding claim 7, the aforementioned Dittmer et al glass ceramic comprises 12.9 wt% Li2O.
Regarding claim 8, the aforementioned Dittmer et al glass ceramic comprises 3.3 wt% Al2O3.
Regarding claim 9, the aforementioned Dittmer et al glass ceramic comprises 2.4 wt% P2O5.
Regarding claims 10-11, the aforementioned Dittmer et al glass ceramic comprises 1.0 wt% K2O.
Regarding claim 12, the aforementioned Dittmer et al glass ceramic comprises 7.7 wt% CaO.
Regarding claim 13, the aforementioned glass ceramic comprises 0 wt% MgO.
Regarding claim 14, the aforementioned Dittmer glass ceramic contains 0 wt% of trivalent oxides selected from those of the claim.
Regarding claim 15, the molar ratio of SiO2/Li2O in the aforementioned Dittmer et al glass ceramic is 2.8.
Regarding claim 16, Dittmer teaches that lithium disilicate is the main crystalline phase in the inventive glass ceramics.
Regarding claim 17, the claim differs from Dittmer et al as applied above because Dittmer et al does not specify the amount of lithium disilicate crystals in terms of wt%. However, as shown above, Dittmer teaches a glass ceramic that is compositionally equivalent to that of the instant claims are that has equivalent crystalline phases. The degree of crystallinity in terms of amount of lithium disilicate phase in a glass ceramic is resultant from the starting composition and the crystallization treatment applied thereto. Dittmer teaches processing by hot pressing and sintering; each of these heat treatments is carried out at temperatures and for times that fall within the ranges disclosed in the instant Specification as leading to the instantly claimed glass ceramics. As such, the equivalently composed and structured glass ceramic taught by Dittmer and discussed above, being processed by equivalent hot pressing and sintering, would inherently also have equivalent crystallinity resultant therefrom. The amount of lithium disilicate would therefore inherently be at least 20 wt%. Each limitation of instant claim 17 is thus met by the teachings of the prior art of record, and the claim is obvious and not patentably distinct.
Regarding claim 18, the claim differs from Dittmer et al as applied above because Dittmer et al does not specify the amount of quartz solution phases in terms of wt%. However, as shown above, Dittmer teaches a glass ceramic that is compositionally equivalent to that of the instant claims are that has equivalent crystalline phases. The degree of crystallinity in terms of amount of quartz solid solution phases in a glass ceramic is resultant from the starting composition and the crystallization treatment applied thereto. Dittmer teaches processing by hot pressing and sintering; each of these heat treatments is carried out at temperatures and for times that fall within the ranges disclosed in the instant Specification as leading to the instantly claimed glass ceramics. As such, the equivalently composed and structured glass ceramic taught by Dittmer and discussed above, being processed by equivalent hot pressing and sintering, would inherently also have equivalent crystallinity resultant therefrom. The amount of quartz solid solution phases would therefore inherently be 0.2-28 wt%. Each limitation of instant claim 18 is thus met by the teachings of the prior art of record, and the claim is obvious and not patentably distinct.
Regarding claim 19, Dittmer et al teaches that the inventive glass ceramic that is equivalent to that of instant claim 1 results from a starting glass that thus meets each limitation of and anticipates instant claim 19.
Regarding claim 20, the Dittmer et al starting glasses are subject to nucleation (see Table 1), and the resultant glass ceramics contain lithium disilicate and two quartz solid solution phases. Said starting glass thus contains nuclei for the crystallization of two different quartz solid solution phase and for lithium disilicate.
Regarding claim 21, Dittmer et al teaches that the inventive glass ceramic is in the form of a blank or dental restoration (see claim 18).
Regarding claim 22, Dittmer et al teaches that the inventive glass ceramic is produced by heating a starting particulate glass in a treatment in a range of 750-900 °C, wherein examples are taught that are heat treated at e.g. 870 °C (see Table 1, example 29).
Regarding claim 25, Dittmer et al teaches that the inventive glass ceramic is shaped into a dental restoration such as a bridge, inlay, onlay, veneer, abutment, partial crown, crown or facet, by pressing or machining (see claim 23.
Conclusion
7. No claim is allowed.
8. The prior art made of record and not relied upon is considered pertinent to applicant's disclosure.
9. Any inquiry concerning this communication or earlier communications from the examiner should be directed to NOAH S WIESE whose telephone number is (571)270-3596. The examiner can normally be reached on Monday-Friday, 7:30am-4:30pm.
If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Amber Orlando can be reached on 571-270-3149. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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/NOAH S WIESE/Primary Examiner, Art Unit 1731
NSW20 November 2025
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