Ex Parte Robb et al

Board of Patent Appeals and Interferences

Jan 24, 2012

10843916 (B.P.A.I. Jan. 24, 2012)

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.
10/843,916 05/12/2004 T. Tait Robb 247168-000270USPT 6102
70001 7590 01/24/2012
NIXON PEABODY, LLP
300 S. Riverside Plaza, 16th Floor
CHICAGO, IL 60606-6613
EXAMINER
LEWIS, RALPH A
ART UNIT PAPER NUMBER
3732
MAIL DATE DELIVERY MODE
01/24/2012 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 T. TAIT ROBB, BRUCE BERCKMANS III,
ROSS W. TOWSE, and ROBERT L. MAYFIELD
____________

Appeal 2010-001525
Application 10/843,916
Technology Center 3700
____________

Before JENNIFER D. BAHR, LINDA E. HORNER, and
EDWARD A. BROWN, Administrative Patent Judges.

HORNER, Administrative Patent Judge.

DECISION ON APPEAL

STATEMENT OF THE CASE
T. Tait Robb et al. (Appellants) seek our review under 35 U.S.C.
§ 134 of the Examiner’s decision rejecting claims 1, 3-10, 12-17, 19, 20, and
22-24 under 35 U.S.C. § 103(a) as unpatentable over Lazzara
(US 5,863,201; iss. Jan. 26, 1999), Hama (US 4,818,559; iss. Apr. 4, 1989),
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and Beaty (US 5,876,453; iss. Mar. 2, 1999). An oral hearing was held on
January 19, 2012. We have jurisdiction under 35 U.S.C. § 6(b). We
REVERSE.
THE INVENTION
Appellants’ claimed invention “relates to roughened surfaces provided
on dental implants to improve the osseointegration of the implant surface
with the bone, thereby shortening the time between initial insertion of the
implant and the installation of a prosthetic tooth.” Spec. 2, ll. 15-18.
Claim 1, reproduced below, is representative of the subject matter on appeal.
1. A method of producing a uniformly roughened surface
on Ti 6/4 alloy for contact with living bone comprising:
(a) removing native oxide from said Ti 6/4 alloy to
expose metal; and
(b) contacting said exposed metal with an aqueous
solution of hydrofluoric acid and hydrochloric acid for a
suitable period of time to create a desired surface topography
having irregularities with peak-to-valley heights of less than 10
microns.
The claims on appeal also include independent method claims 8, 20,
and 24 and independent apparatus claims 14 and 22. Independent method
claim 8 is similar to claim 1 and further recites ranges for the specific
concentrations of the acids in the aqueous solution. Independent method
claim 20 is similar to claim 1 except in step (b) the aqueous solution is
Keller’s Solution.1 Independent method claim 24 is directed to a method of
producing a uniformly roughened surface on a dental implant using steps
similar to claim 1 and recites that the exposed metal surface in step (b)

1 Keller’s Solution contains hydrofluoric acid, nitric acid, and hydrochloric
acid. Spec. 9, l. 2.
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includes a neck section and a threaded section directly below the neck
section. Independent apparatus claim 14 is directed to a dental implant of Ti
6/4 alloy with a threaded section having a desired roughened surface
topography having irregularities with peak-to-valley heights of less than 10
microns created by etching the threaded portion with the aqueous solution of
claim 8. Independent apparatus claim 22 is directed to a dental implant
assembly having a threaded section comprising Ti 6/4 alloy and a roughened
surface topography having irregularities with peak-to-valley heights of less
than 10 microns created by etching the threaded portion with the aqueous
solution of claim 1.
ISSUE
The Examiner determined that, in light of the disclosure in Hama that
mineral acids such as sulfuric acid, hydrochloric acid, and hydrofluoric acid,
alone or in combination of two or more can be used to etch the surface of a
dental implant, it would have been obvious to use the claimed combination
of hydrofluoric acid and hydrochloric acid or Keller’s Solution in the surface
roughening method of Beaty on the dental implant of Lazzara made from Ti
6/4 alloy “as a matter of routine practice.” Ans. 4. Appellants presented
evidence to show that one of ordinary skill in the art would not have viewed
these acids as interchangeable and that an acid mixture including
hydrofluoric acid would not have been expected to create a roughened
surface topography of less than 10 microns on a Ti 6/4 alloy. App. Br. 15;
Reply Br. 2. The issue presented by this appeal is:
Would the disclosure in Hama of a method for producing endosseous
implants have led one of ordinary skill in the art to modify the surface
roughening method of Beaty employed in Lazzara to use hydrofluoric acid
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in an aqueous solution to etch a Ti 6/4 alloy dental implant to achieve the
claimed surface topography?
FINDINGS OF FACT
We find that the following enumerated findings are supported by at
least a preponderance of the evidence.
1. Appellants’ Specification describes that the procedure used on
commercially pure titanium dental implants to create a surface of
generally uniform peaks with a maximum peak-to-valley height of
10 µm or less by removing a native oxide layer and etching with a
solution of hydrochloric and sulfuric acids surprisingly did not
provide the same surface topography when performed on Ti 6/4 alloy
implants. Spec. 6, l. 19 – 7, l. 2; Spec. 8, ll. 13-17; fig. 1E.
2. Appellants provide the Declaration of Keith D. Beaty Under 37 C.F.R.
§ 1.132 (“Beaty Decl.”). Mr. Beaty is a founder of Biomet 3i, the real
party-in-interest, has a bachelor of science in engineering, and worked
in the dental implant industry, including involvement with the design
of dental implant products, since 1987. Beaty Decl. at paras. 2, 3.
3. Appellants also provide the Declaration of Richard J. Lazzara Under
37 C.F.R. § 1.132 (“Lazzara Decl.”). Dr. Lazzara is also a founder of
Biomet 3i, has a doctorate of dental medicine, a degree in
periodontics, and a master of science in dentistry, currently practices
periodontics and implant dentistry, and has worked in the dental
implant industry, including involvement with the design of dental
implant products, since 1987. Lazzara Decl. at paras. 1-3.
4. Both Mr. Beaty and Dr. Lazzara declare that “Hama teaches the
general use of acids, such as sulfuric acid, hydrochloric acid, and
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hydrofluoric acid, to create a surface roughness in the range of
15 microns to 100 microns” to adhere ceramic coating to a metallic
core. Beaty Decl. at paras. 7, 8; Lazzara Decl. at paras. 8, 9.
5. Mr. Beaty and Dr. Lazzara declare that “it appears from Hama that
using hydrochloric acid and hydrofluoric acid to etch an implant
surface would not obtain the desired surface topography of less than
10 microns.” Beaty Decl. at para. 8; Lazzara Decl. at para. 9.
6. Mr. Beaty and Dr. Lazzara further declare that at the time of
Appellants’ invention, “using hydrofluoric acid to etch an implant
surface was considered an aggressive treatment” and that “[r]egardless
of the concentration and the duration of exposure, an acid mixture
including hydrofluoric acid would not have been expected to create a
roughened surface topography of less than 10 microns on a Ti 6/4
alloy.” Beaty Decl. at para. 10; Lazzara Decl. at para. 11.
7. Mr. Beaty and Dr. Lazzara further declare that “different acids (and
acid mixtures) react differently on different types of metals, producing
unpredictable degrees of surface roughness” and “[m]erely
interchanging metals and/or acids does not produce the same result.”
Beaty Decl. at para. 11; Lazzara Decl. at para. 12.
8. Hama discloses applying ceramic coating to the surface of a metallic
dental implant core material to obtain an implant with a good affinity
to the surrounding bone tissues. Col. 1, ll. 48-52; col. 2, ll. 59-63.
9. Hama discloses that the metallic core materials can be “any
conventional materials which have usually been used as artificial
materials for bones, joints and tooth roots which do not exhibit
harmful effects on living bodies and possess an appropriate
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mechanical strength, for example, cobalt-chromium alloys, stainless
steels, titanium, titanium alloys, tantalum, zirconium, and the like.”
Col. 2, l. 65 – col. 3, l. 3.
10. Hama discloses that the preferred materials are titanium, titanium
alloys, zirconium and tantalum for their excellent corrosion resistance,
and most preferred are titanium and titanium alloys (e.g., 6% Al – 4%
V-Ti) for “their excellent processability and safety.” Col. 3, ll. 3-8.
11. Hama discloses that the surface of the metallic core materials is made
rough to a maximum surface roughness “in the range of 15 µm to
100 µm” and that “[w]hen the maximum surface roughness is smaller
than 15 µm, the thermally sprayed ceramic coating layer demonstrates
insufficient adhesion.” Col. 3, ll. 28-35.
12. Hama discloses that to make the surface of the metallic core materials
rough chemical etching can be carried out “using mineral acids, such
as sulfuric acid, hydrochloric acid, hydrofluoric acid, which are used
alone or in combination of two or more thereof.” Col. 3, ll. 41-55.
13. Lazzara discloses a titanium alloy implant which is roughened to
improve osseointegration with the bone using the method of
roughening disclosed in Beaty. Col. 1, ll. 62-63; col. 2, ll. 48-49,
59-65.
14. Beaty’s process includes removal of the native oxide layer “by
immersing the titanium implant in an aqueous solution of hydrofluoric
(HF) acid at room temperature” and then subjecting the implant to “a
relative mild acid-etching treatment which forms a multitude of fine
cone-like structures having relative uniform, small dimensions.”
Col. 5, ll. 1-3, 54-57.
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15. Beaty discloses:
The treatment that follows removal of the native oxide
layer must be different from the treatment that is used to
remove the native oxide layer. A relatively aggressive
treatment is normally required to remove the oxide layer,
and such an aggressive treatment does not produce the
desired uniform surface texture in the resulting oxide-free
surface.
Col. 5, ll. 44-49.
16. Beaty discloses that the acid etching step uses
an etch solution (“Modified Muriaticetch”) consisting of
a mixture of two parts by volume sulfuric acid (96% by
weight H2SO4, 4% by weight water) and one part by
volume hydrochloric acid (37% by weight HCl, 63% by
weight water) at a temperature . . . preferably in the range
from about 60ºC to about 80ºC
and that “the final etched surface consists of a substantially uniform
array of irregularities having peak-to-valley heights of less than about
10 microns.” Col. 6, ll. 7-15, 31-34.
ANALYSIS
Independent Method Claims 1, 8, 20, and 24
The evidence before us supports Appellants’ position that one of
ordinary skill in the art would not have been led by the disclosure in Hama
to use hydrofluoric acid in the aqueous acid mixture of Beaty’s method to
achieve a surface topography having irregularities with peak-to-valley
heights of less than 10 microns. Hama provides merely a category of acids
that may be used to chemically etch a list of metals to produce a surface
roughness of 15 µm to 100 µm for adhering a ceramic coating to the metal
(Facts 8-12). The Specification and the Declarations of Mr. Beaty and
Dr. Lazzara show that hydrofluoric acid was not interchangeable with the
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acids of Beaty’s method and its use to etch a Ti 6/4 alloy dental implant to
achieve the claimed surface topography was more than the predictable use of
prior art elements according to their established functions (Facts 1-7). The
prior art further shows that one of ordinary skill in the art at the time of
Appellants’ invention considered hydrofluoric acid too aggressive to use in
the second acid etch step of Beaty’s method (Facts 14-16). For these
reasons, we do not sustain the obviousness rejection of the method claims.
Apparatus claims 14 and 22
While apparatus claims 14 and 22 are directed to an implant and
implant assembly, respectively, having a roughened surface topography
created by a particular process, and thus contain product-by-process
limitations, the prior art process of Beaty does not produce the claimed
surface topography when performed on Ti 6/4 alloy (Fact 1). Thus, the
Examiner’s conclusion of obviousness of these apparatus claims appears to
be based on the determination that one of ordinary skill in the art would have
been led by the disclosure in Hama to use hydrofluoric acid in the aqueous
solution of Beaty’s method to etch Ti 6/4 alloy. For the reasons provided
supra in our analysis of the method claims, we agree with Appellants that
Hama would not have led one of ordinary skill in the art to modify Beaty’s
method to use hydrofluoric acid in an aqueous solution to etch a Ti 6/4 alloy
such that the claimed roughened surface topography would result. For these
reasons, we do not sustain the obviousness rejection of the apparatus claims.
CONCLUSION
The disclosure in Hama of a method for producing endosseous
implants would not have led one of ordinary skill in the art to modify the
surface roughening method of Beaty employed in Lazzara to use
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hydrofluoric acid in an aqueous solution to etch a Ti 6/4 alloy dental implant
to achieve the claimed surface topography.
DECISION
The decision of the Examiner to reject claims 1, 3-10, 12-17, 19, 20,
and 22-24 is REVERSED.

REVERSED

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