Prosecution Insights
Last updated: April 19, 2026
Application No. 18/238,671

METHOD FOR PRODUCING ACID-REACTIVE GLASS POWDER, ACID-REACTIVE GLASS POWDER OBTAINED BY THE PRODUCTION METHOD, AND DENTAL GLASS IONOMER CEMENT COMPOSITION CONTAINING THE SAME

Non-Final OA §102§103§112
Filed
Aug 28, 2023
Examiner
WIESE, NOAH S
Art Unit
1731
Tech Center
1700 — Chemical & Materials Engineering
Assignee
Kabushiki Kaisha Shofu
OA Round
1 (Non-Final)
83%
Grant Probability
Favorable
1-2
OA Rounds
2y 4m
To Grant
80%
With Interview

Examiner Intelligence

Grants 83% — above average
83%
Career Allow Rate
929 granted / 1118 resolved
+18.1% vs TC avg
Minimal -3% lift
Without
With
+-3.0%
Interview Lift
resolved cases with interview
Typical timeline
2y 4m
Avg Prosecution
45 currently pending
Career history
1163
Total Applications
across all art units

Statute-Specific Performance

§101
0.2%
-39.8% vs TC avg
§103
50.8%
+10.8% vs TC avg
§102
20.8%
-19.2% vs TC avg
§112
24.9%
-15.1% vs TC avg
Black line = Tech Center average estimate • Based on career data from 1118 resolved cases

Office Action

§102 §103 §112
DETAILED ACTION The claims 1-9 are pending and presented for the examination. Notice of Pre-AIA or AIA Status The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA . Priority Receipt is acknowledged of certified copies of papers required by 37 CFR 1.55. Information Disclosure Statement The information disclosure statements (IDS) submitted on 08/28/2023 and 03/12/2024 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. Claims 1-4 are 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. Claim 1 recites that there is a powder that is pulverized that is a large-particle-size powder, and that said pulverizing is done “in a state” where a small-particle-size powder “coexists” therewith. From this language, the natures of the these two powders and how they are or are not combined is unclear. The language “coexists” does not necessarily mean that the two powders are mixed or are even present in the same physical container or space. As such, it is not clear what sort of process step is occurring during the pulverization. Because of the ambiguity resultant from the use of the “coexists” term, the metes and bounds of claim 1 are indefinite under USC 112. For purposes of examination on merits, the claimed process will be interpreted as one in which the two types of powders are mixed together or are otherwise in contact with one another during the pulverization process. Claim 1 is further indefinite because the terminology used for the particle size distribution is no standard or fully clear. Describing the powder as “having a range of 250 to 3000 µm of a 50% particle size” is not sufficiently clear as to whether this is meant to refer to the size below which the diameters of 50% of the particles fall. Such is the commonly used parameter for describing particle size distributions, and it should be clarified if this is meant to indicate that the D50 size of the large-particle-size powder is, in fact, what is being claimed. The equivalent limitation for the small-particle-size powder is similarly indefinite for the same reasons. Claim 4 is similarly indefinite and it should be clarified that the terms “10% particle size” and “90% particle size” are meant to refer to the value that 10% or 90% of the particles fall below in terms of diameter. Claims 2-3 are indefinite as dependent from claim 1 and therefore containing the indefinite limitations thereof. Claim Rejections - 35 USC § 102 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. Claims 5-8 are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Yoshimitsu et al (US 2021/0196580 A1). Regarding claim 5, the claim is a product-by-process claim that is drawn to a glass powder that is able to be obtained by the method of claim 1. As discussed in further detail below, Yoshimitsu et al teaches a method of forming a glass powder that meets each limitation of the instant process claim 1. The powder produced by the Yoshimitsu et al method would thus meet each limitation of instant claim 5. Further, as the Yoshimitsu et al glass powder meets each particle size limitation of the final product glass powder of claim 1, the prior art powder in question would also anticipate that claimed as product-by-process in this claim even if the intermediate particle sizes recited in the process limitations were not met. The claim coverage of a product claim is dictated by what is resultant and present in the final product, and not by features of intermediate or starting products. Claim 5 is therefore anticipated by the prior art of record. Regarding claim 6, the claim is a product-by-process claim that is drawn to a glass powder that is able to be obtained by the method of claim 4. As discussed in further detail below, Yoshimitsu et al teaches a method of forming a glass powder that meets each limitation of the instant process claim 1. The powder produced by the Yoshimitsu et al method would thus meet each limitation of instant claim 6. Further, as the Yoshimitsu et al glass powder meets each particle size limitation of the final product glass powder of claim 4, the prior art powder in question would also anticipate that claimed as product-by-process in this claim even if the intermediate particle sizes recited in the process limitations were not met. The claim coverage of a product claim is dictated by what is resultant and present in the final product, and not by features of intermediate or starting products. Claim 6 is therefore anticipated by the prior art of record. Regarding claim 7, Yoshimitsu et al teaches that the inventive glass powder is used as a part of a dental ionomer cement. Regarding claim 8, Yoshimitsu et al teaches that the inventive glass powder is used as a part of a dental ionomer cement. Claim Rejections - 35 USC § 103 The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action: A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made. The factual inquiries for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows: 1. Determining the scope and contents of the prior art. 2. Ascertaining the differences between the prior art and the claims at issue. 3. Resolving the level of ordinary skill in the pertinent art. 4. Considering objective evidence present in the application indicating obviousness or nonobviousness. This application currently names joint inventors. In considering patentability of the claims the examiner presumes that the subject matter of the various claims was commonly owned as of the effective filing date of the claimed invention(s) absent any evidence to the contrary. Applicant is advised of the obligation under 37 CFR 1.56 to point out the inventor and effective filing dates of each claim that was not commonly owned as of the effective filing date of the later invention in order for the examiner to consider the applicability of 35 U.S.C. 102(b)(2)(C) for any potential 35 U.S.C. 102(a)(2) prior art against the later invention. Claims 1 and 4 are rejected under 35 U.S.C. 103 as being unpatentable over Yoshimitsu et al (US 2021/0196580 A1). Regarding claim 1, the claim recites a method in which a glass powder is produced by pulverizing a glass powder described as a large-particle-size powder, said pulverizing caried out “in a state” wherein a small-particle-size powder “coexists” therewith. The resultant pulverized powder has a certain 50% particle size. It is not required by the claim limitations that said large-particle-size powder and said small-particle-size powder are produced separately, or are mixed before pulverization. Thus, the distinction between the two powders having different sizes only indicates that there is some portion of the particulate having a 50% particle size of 250-3000 µm (large-particle-size), and some other portion of the particulate having a 50% size of 1-5 µm (small-particle-size). These two portions can be produced during the pulverization and would still be within the coverage of the instant claim limitations; in such cases, the portion arbitrarily chosen as small-particle-size would be considered to “coexist” with the portion chosen to meet the large-particle-size portion. In the method taught by Yoshimitsu et al, a glass is produced by melting and then crushed to eventually form a glass having a D5-0 size of i.e. 6.3 µm, 5.1 µm, 6.9 µm (see Table 1). At some period after pulverization begins, there would necessarily exist a particulate portion having a size of 250-3000 µm, as the melt-formed glass would being as pieces larger than this size; this portion during pulverization would constitute a large-particle-size portion meeting the instant claim limitation. A D50 size of close to 5 µm would necessarily indicate the presence of particles with a size less than 5 µm and between 1-5 µm. Thus, this portion would constitute a small-particle-size portion meeting the limitation of the instant claims. Though not specifically disclosed, it would have been obvious to one of ordinary skill in the art that the pulverizing method taught by Yoshimitsu would be one in which particle portions meeting the two size limitations of the instant claim would coexist during the formation of a particle having a D50 size falling within the instantly claimed range. Each limitation of claim 1 is therefore met by the teachings of the prior art of record, and the claim is obvious and not patentably distinct. Regarding claim 4, Yoshimitsu et al teaches embodiments such that the difference between the D90 and D10 particle sizes are within the range 9-25 µm (see Table 1). Claim 9 is rejected under 35 U.S.C. 103 as being unpatentable over Yoshimitsu et al (US 2021/0196580 A1) in view of Peez et al (US 10080708 B2). Regarding claim 9, Yoshimitsu et al teaches that the inventive glass powder is used in an ionomer cement in combination with polyacrylic acid and water. Said polyacrylic acid is a type of polyalkenoic acid. The claim differs from Yoshimitsu et al because Yoshimitsu et al teaches only an embodiment wherein 50% of the glass powder is mixed with an aqueous solution of the polyacrylic acid to form the cement, and thus does not teach an embodiment wherein the content of glass powder is 60-80 wt%. However, it would have been obvious to one of ordinary skill in the art to modify Yoshimitsu et al in view of Peez et al in order to form ionomer cements as taught therein. Peez et al teaches glass ionomer cement compositions, and teaches ranges for each of the components that are also taught in the Yoshimitsu et al cement. Peez et al teaches cements formed from mixtures of Part A comprising 60-95 wt% glass powder, and Part B comprising 40-60 wt% polyacid and 30-70 wt% water (see claims 1 and 10); Part A is present in a weight ratio of 2:1-4:1 relative to Part B (see claim 8). From these ranges, a cement comprising 50-80 wt% glass powder, 5-25 wt% polyalkenoic acid, and 10-25 wt% water would be produced through routine optimization and experimentation. The glass content of Part A is the substantial portion of the component, thus 66-75 wt% Part A would constitute a range of in terms of glass powder that would overlap the range of the instant claim. Further, the polyacid and water portions of the Part B component are closely equivalent, so a remainder constituting 25-33 wt% Part B would lead to polyacid and water amounts each also falling within the 10-25 wt% or 5-25 wt% range of the instant claims. It would have been obvious to one of ordinary skill in the art at the time the invention was made to have selected from the overlapping portion of the ranges disclosed by the reference because overlapping ranges have been held to establish prima facie obviousness. See MPEP 2144.05. One of ordinary skill in the art would have had motivation to use the ranges taught by Peez et al when preparing the ionomer cements taught by Yoshimitsu et al because Yoshimitsu et al only provides for a single cement composition in terms of water, glass, and acid contents, and Peez et al shows that broader ranges for these contents are possible and lead to advantageously composed cements. One would have had a reasonable expectation of success in the modification because Yoshimitsu et al and Peez et al are drawn to substantially similar glass powders and ionomer cements made therefrom. Each limitation of claim 9 is therefore met by the teachings of the prior art of record, and the claim is obvious and not patentably distinct. Allowable Subject Matter Claims 2-3 would be allowable if rewritten to overcome the rejection(s) under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), 2nd paragraph, set forth in this Office action and to include all of the limitations of the base claim and any intervening claims. The prior art, either alone or in combination, fails to teach or suggest a method meeting each limitation of instant claim 1 as they are interpreted for purposes of examination on merits as discussed above, and further having the particle size distribution features of instant claims 2 or 3. Conclusion 15. No claim is allowed. 16. The prior art made of record and not relied upon is considered pertinent to applicant's disclosure. 17. 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. Information regarding the status of an application may be obtained from the Patent Application Information Retrieval (PAIR) system. Status information for published applications may be obtained from either Private PAIR or Public PAIR. Status information for unpublished applications is available through Private PAIR only. For more information about the PAIR system, see http://pair-direct.uspto.gov. Should you have questions on access to the Private PAIR system, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative or access to the automated information system, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000. /NOAH S WIESE/Primary Examiner, Art Unit 1731 NSW27 February 2026
Read full office action

Prosecution Timeline

Aug 28, 2023
Application Filed
Feb 27, 2026
Non-Final Rejection — §102, §103, §112 (current)

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Study what changed to get past this examiner. Based on 5 most recent grants.

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Prosecution Projections

1-2
Expected OA Rounds
83%
Grant Probability
80%
With Interview (-3.0%)
2y 4m
Median Time to Grant
Low
PTA Risk
Based on 1118 resolved cases by this examiner. Grant probability derived from career allow rate.

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