Homann, Frank et al.

Patent Trials and Appeals Board

Sep 6, 2019

14484572 - (D) (P.T.A.B. Sep. 6, 2019)

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.
14/484,572 09/12/2014 Frank Homann 164147.02 6655
25944 7590 09/06/2019
OLIFF PLC
P.O. BOX 320850
ALEXANDRIA, VA 22320-4850
EXAMINER
PHAM, THOMAS T
ART UNIT PAPER NUMBER
1713
NOTIFICATION DATE DELIVERY MODE
09/06/2019 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):
OfficeAction25944@oliff.com
jarmstrong@oliff.com
PTOL-90A (Rev. 04/07)
UNITED STATES PATENT AND TRADEMARK OFFICE
____________

BEFORE THE PATENT TRIAL AND APPEAL BOARD
____________

Ex parte FRANK HOMANN and PHILIPPE HABERSETZER
____________

Appeal 2019-000885
Application 14/484,572
Technology Center 1700
____________

Before JEFFREY B. ROBERTSON, MONTÉ T. SQUIRE, and
JANE E. INGLESE, Administrative Patent Judges.

ROBERTSON, Administrative Patent Judge.

DECISION ON APPEAL1

STATEMENT OF THE CASE

Appellant2 appeals under 35 U.S.C. § 134(a) from the Examiner’s
Final Rejection of claims 25, 27–40, 42–52, 55, and 56. (Appeal Br. 8.) We
have jurisdiction pursuant to 35 U.S.C. § 6(b).
We REVERSE.

1 This Decision includes citations to the following documents:
Specification filed September 12, 2014 (“Spec.”); Final Office Action
mailed January 22, 2018 (“Final Act.”); Appeal Brief filed June 20, 2018
(“Appeal Br.”); Examiner’s Answer mailed September 21, 2018 (“Ans.”);
and Reply Brief filed November 14, 2018 (“Reply Br.”).
2 Appellant/Applicant is Straumann Holding AG, which is also identified in
the Appeal Brief as the real party in interest. (Appeal Br. 1.)
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Application 14/484,572

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THE INVENTION
Appellant states the invention relates to a process for providing a
topography to the surface of a dental implant using a solution comprising
hydrofluoric acid in order to etch a ceramic surface of the dental implant.
(Spec. 1, ll. 12–16.)
Claim 25 is representative and reproduced below from the Claims
Appendix to the Appeal Brief:
25. A process for providing a topography to the surf ace of a
dental implant, said surface being made of a ceramic
material consisting of yttria-stabilized zirconia, the
process comprising:
roughening the surface of the dental implant by a
mechanical process and/or injection molding technique; and
etching at least a part of the roughened surface,
wherein the etching is carried out using an etching solution
comprising hydrofluoric acid at a temperature of at least 70
°C, such that discrete grains or agglomerates of grains are
removed from the yttria-stabilized zirconia, thereby forming
recesses and cavities in the roughened surface.
(Appeal Br. (Claims Appendix) A-1.)
Claims 40 and 55 are also independent claims, and recite processes of
treating the surface of a dental implant made of a ceramic material including
yttria-stabilized zirconia with hydrofluoric acid at a temperature of at least
70 °C. (Id. at A-2–A-4.)

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REJECTIONS3
1. The Examiner rejected claims 25, 27–40, 42–52, and 55 under pre-
AIA 35 U.S.C. § 103(a) as obvious over Gahlert (US 2005/0106534
A1, published May 19, 2005), Suzuki et al. (US 2004/0267736 A1,
published December 30, 2004, hereinafter “Suzuki”), and Morita et al.
(US 2003/0215643 A1, published November 20, 2003, hereinafter
“Morita”).
2. The Examiner rejected claims 28 and 43 under pre-AIA 35 U.S.C.
§ 103(a) as obvious over Gahlert, Suzuki, Morita, and Chatterjee et al.
(US 5,855,173; issued January 5, 1999, hereinafter “Chatterjee”).
3. The Examiner rejected claim 56 under pre-AIA 35 U.S.C. § 103(a) as
obvious over Gahlert, Suzuki, Morita, and Chakupurakal (US
4,327,122; issued April 27, 1982).
(Final Act. 5–10; Ans. 3–6.)
We limit our discussion to claim 25, which is sufficient for disposition
of this appeal.
Rejection 1
ISSUE
The Examiner found Gahlert discloses a method of roughening a
dental implant of yttria-stabilized zirconia including roughening the surface
by a mechanical process such as sandblasting and etching the roughened
surface with phosphoric acid, hydrochloric acid, sulfuric acid, or mixtures
thereof. (Final Act. 5, citing Gahlert, ¶¶ 9, 10, 15, 30–33, and 71.) The

3 The Examiner withdrew all rejections under 35 U.S.C. § 112, first
paragraph set forth in the Final Action. (See Ans. 6; Final Act. 2–4.)
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Examiner found Gahlert is silent as to the temperature of the acid, and
Gahlert fails to disclose roughening by treating with hydrofluoric acid. (Id.)
The Examiner found Suzuki discloses a method for roughening a
medical implant to improve its binding with bones, the method including
treating the medical implant with a strong acid such as hydrofluoric acid,
phosphoric acid, hydrochloric acid, nitric acid, or mixtures thereof at about
40–80 °C, where for implants including zirconia and an amount of other
oxides, hydrofluoric acid is preferred. (Id. at 6, citing Suzuki, Abstract,
¶¶ 42, 44, and 45.) The Examiner found Morita discloses a method of
roughening an article including zirconia-yttria composite, by treating the
surface with hydrofluoric acid. (Id., citing Morita, ¶ 30.)
The Examiner determined it would have been obvious to have used an
acid comprising hydrofluoric acid as an equivalent acid to roughen the
dental implant in Gahlert, because Gahlert and Suzuki disclose similar acids
and Suzuki discloses hydrofluoric acid is preferred, and because Morita
discloses surfaces of zirconia-yttria composites may roughened by treating
with hydrofluoric acid. (Id. at 6–7.) The Examiner determined that it would
have been obvious to have used the acid at 40–80 °C, because Gahlert is
silent about a temperature of the acid and Suzuki teaches to use such
temperatures. (Id. at 7.)
Appellant argues, inter alia, that Suzuki does not disclose etching
yttria-stabilized zirconia using an etching solution comprising hydrofluoric
acid at a temperature of at least 70 °C. (Appeal Br. 13.) In particular,
Appellant contends Suzuki teaches away from using yttria-stabilized
zirconia. (Id. at 14–15.) Appellant argues Suzuki teaches away from
mechanical roughening. (Id. at 20–23.)
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Accordingly, the dispositive issue with respect to this rejection is: has
Appellant identified a reversible error in the Examiner’s determination that it
would have been obvious to have employed an etching solution of
hydrofluoric acid at a temperature of at least 70 °C as the etching solution in
treating the yttria-stabilized zirconia dental implants in Gahlert?

DISCUSSION
We are persuaded by Appellant’s arguments that one having ordinary
skill in the art would not have combined Gahlert and Suzuki to arrive at the
method recited in claim 25 as suggested by the Examiner. (Appeal Br. 15,
21.) In particular, as Appellant points out, Suzuki discloses a method for
producing a ceramic member for a medical implant including the steps of
etching a ceramic member with a strong acid solution and then subjecting
the etched ceramic material to a heat treatment at 1000 °C to 1800 °C.
(Suzuki, ¶ 12.) Suzuki discloses that in contrast to conventional situations
where a zirconia composite ceramic material for an implant member is
polished with an alumina slurry and then further etched with acid solution,
Suzuki’s method does not suffer from the loss of mechanical properties. (Id.
at ¶¶ 8, 9, 13, 15, 16.) Suzuki discloses that although the bond between
crystal grains of ceramic material is weakened by the strong acid treatment,
the crystals recover their bonding during the heat treatment step. (Id. at
¶ 16.)
Suzuki discloses also that when the ceramic material contains a
“single composition” such as 3Y zirconia (yttria-stabilized zirconia),
formation of desired microirregularities is “rather difficult” because the
“surface will be smoothened during the subsequent diffusion bonding by the
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heat treatment due to the weak bonding between the crystal grains.” (Id. at
¶ 42; Appeal Br. 15.)
The Examiner’s position is that the claims do not recite any heat
treatment step after chemical etching, and because the 3Y zirconia substrate
discussed in Suzuki is different than the yttria-stabilized zirconia disclosed
in Gahlert, which also does not disclose a heat treatment, one of ordinary
skill in the art would not perform a subsequent heat treatment as disclosed in
Suzuki when combined with Gahlert. (Ans. 8–9.) However, the Examiner’s
position is not based on sufficient rational underpinnings.
That is, as pointed out by Appellant, whether a heat treatment step
appears in the claims does not speak to the reasoning for combining the prior
art. (Reply Br. 7.) In this regard, the Examiner does not provide adequate
support for the position that 3Y zirconia in Suzuki is different than the
yttria-stabilized zirconia disclosed in Gahlert as a basis for omitting the heat
treatment step in Suzuki. Rather, the evidence of record favors Appellant’s
position that the yttria-stabilized zirconia materials in Gahlert and Suzuki
contain substantially the same proportion of yttria. (Id. at 8; Gahlert ¶¶ 10,
71.) Thus, the Examiner’s reasoning for discounting the heating step of
Suzuki is not supported on this basis.
In addition, the Examiner has not considered the prior art as a whole,
where Suzuki discloses issues with combining mechanical roughening
process and acid etching process as disclosed in Gahlert. (Suzuki, ¶ 13;
Gahlert, ¶¶ 30–33.) As discussed above, Suzuki discloses the heating step is
needed to strengthen the weakened bonds in the crystal grains as a result of
using the heated strong acid solution for etching, and in the case of yttria-
stabilized zirconia, the heating step smooths the surface. (Suzuki, ¶ 42.)
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Thus, the Examiner has not provided adequate reasoning to support the
position that one of ordinary skill would have combined Gahlert and Suzuki
to employ hydrofluoric acid at at least 70 °C in treating yttria-stabilized
zirconia without the subsequent heat treatment needed to strengthen the
crystal grains and maintain the desired surface roughness desired in Gahlert.
(Gahlert ¶ 27; Appeal Br. 15; Reply Br. 11–12.)
As a result we reverse the Examiner’s rejection of claim 25 as well as
claims 27–40, 42, 44–52, and 55 subject to Rejection 1.

Rejections 2 and 3
Rejections 2 and 3 are directed to dependent claims, and are deficient
for the same reasons as identified above; and the addition of Chatterjee in
Rejection 2 and Chakupurakal in Rejection 3 is insufficient to remedy such
deficiencies. As a result, we reverse the rejection of claims 28 and 43
subject to Rejection 2 and claim 56, subject to Rejection 3 for similar
reasons.

DECISION
We reverse the Examiner’s decision rejecting claims 25, 27–40, 42–
52, 55, and 56.

REVERSED