Ex Parte Hurson

Patent Trial and Appeal Board

Nov 15, 2013

12172881 (P.T.A.B. Nov. 15, 2013)

UNITED STATES PATENT AND TRADEMARK OFFICE
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BEFORE THE PATENT TRIAL AND APPEAL BOARD
__________

Ex parte STEVEN M. HURSON
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Appeal 2012-001540
Application 12/172,881
Technology Center 3700
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Before FRANCISCO C. PRATS, ERICA A. FRANKLIN, and
JOHN G. NEW, Administrative Patent Judges.

FRANKLIN, Administrative Patent Judge.

DECISION ON APPEAL
This is an appeal under 35 U.S.C. § 134(a) involving claims to dental
implants. The Patent Examiner rejected the claims as obvious. We have
jurisdiction under 35 U.S.C. § 6(b). We reverse.

STATEMENT OF THE CASE
Claims 1-25 are on appeal. Claims 1, 9, and 23 are representative and
read as follows:
1. A dental implant for supporting a dental prosthesis, the implant
comprising:
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a body comprising an outer surface, an apical end, a coronal end, a
threaded portion and a longitudinal axis, the coronal end of the body
comprising a collar, the threaded portion comprising a coronal portion
configured to engage cortical bone and an apical portion configured to
engage cancellous bone, the threaded portion further comprising at least one
thread extending from a root surface that forms a longitudinal side of the
body, the at least one thread comprising a coronal flank, an apical flank, and
a thread face that defines a length extending between the coronal flank and
apical flank, wherein the length of the thread face is larger in the apical
portion than the coronal portion and the thread has a thread depth d3 in the
coronal portion of the thread that is less than a thread depth d4 in the apical
portion and the coronal flank and the apical flank in the coronal portion form
an angle that is greater than an angle formed by the coronal flank and the
apical flank in the apical portion and wherein the thread face of at least a
portion of the at least one thread is substantially flat.

9. A dental implant for supporting a dental prosthesis, the implant
comprising:
a body comprising an outer surface, an apical end, a coronal end, a
coronal portion, a threaded portion and a longitudinal axis, the coronal
portion of the body comprising a collar, the collar tapering outwardly with
respect to the longitudinal axis, the threaded portion comprising a coronal
portion, an intermediate portion and an apical portion, the threaded portion
further comprising at least one thread extending from a root surface, the at
least one thread comprising a face that forms a thread face surface,
in the intermediate portion of the threaded portion, the root surface
tapering inwardly at a first angle with respect to the longitudinal axis,
in the apical portion of the threaded portion the root surface tapering
inwardly at a second angle with respect to the longitudinal axis, the first
angle being greater than the second angle;
the at least one thread comprising a coronal flank, an apical flank, and
the face extending between the coronal flank and apical flank.

23. A dental implant for supporting a dental prosthesis, the implant
comprising:
a body comprising an outer surface, an apical end, a coronal end, a
threaded portion and a longitudinal axis, the coronal end of the body
comprising a collar, the threaded portion comprising a coronal portion, an
intermediate portion and an apical portion, the threaded portion further
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comprising at least one thread extending from a root surface, the at least one
thread comprising a coronal flank, an apical flank, and a face extending
between the coronal flank and apical flank, wherein the thread face has a
thickness that generally increases from the coronal portion to the apical
portion and wherein at least in the apical portion the face of the at least one
thread is substantially flat.

(Emphasis added.)
The Examiner rejected the claims as follows:
• claims 1-4 under 35 U.S.C. § 103(a) as unpatentable over Hansson1
and Fromovich;2
• claims 5-7 under 35 U.S.C. § 103(a) as unpatentable over Hansson,
Fromovich, and Lazzara;3
• claim 8 under 35 U.S.C. § 103(a) as unpatentable over Hansson,
Fromovich, and Cuilleron;4
• claims 9, 10, 14, 19, and 22 under 35 U.S.C. § 103(a) as
unpatentable over Hansson, and Schlapfer;5
• claim 11 under 35 U.S.C. § 103(a) as unpatentable over Hansson,
Schlapfer, and Kownacki;6
• claims 12, 13, 15, 16, 18, and 20-21 under 35 U.S.C. § 103(a) as
unpatentable over Hansson, Schlapfer, and Cuilleron;

1 Patent No. US 6,547,564 B1 issued to Stig Hansson, Apr. 15, 2003.
2 Patent Application Publication No. US 2007/0099153 A1 by Ophir
Fromovich, published May 3, 2007.
3 US Patent No. 5,702,346 issued to Richard J. Lazzara et al., Dec. 30, 1997.
4 Jean Cuilleron, FR 2,610,512, published Feb. 6, 1987.
5 US Patent No. 6,585,740 B2 issued to Fridolin J. Schlapfer et al., Jul. 1,
2003.
6 US Patent No. 5,816,812 issued to Charles D. Kownacki et al., Oct. 6,
1998.
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• claim 17 under 35 U.S.C. § 103(a) as unpatentable over Hansson,
Schlapfer, Cuilleron, and Fontenot;7
• claims 23-24 under 35 U.S.C. § 103(a) as unpatentable over
Hansson, and Choi;8
• claim 25 under 35 U.S.C. § 103(a) as unpatentable over Hansson,
Choi, and Cuilleron.

OBVIOUSNESS
I. Claim 1
The Examiner found that Hansson taught a dental implant for
supporting a dental prosthesis as substantially claimed, including at least one
thread comprising a thread face that defines a length extending between the
coronal flank and apical flank, wherein the length of the thread face is larger
in the apical portion than in the coronal portion. (Ans. 5.) However, the
Examiner found that Hansson did not teach “the coronal flank and the apical
flank [in the coronal portion] form an angle that is greater than an angle
formed by the coronal flank and the apical flank in the apical portion and
wherein the thread face of at least a portion of the at least one thread is
substantially flat.” (Id.)
The Examiner found that Fromovich taught a dental implant wherein
(a) the coronal flank and the apical flank in the coronal portion form an
angle that is greater than an angle formed by the coronal flank and the apical

7 US Patent No. 5,639,237 issued to Mark G. Fontenot, Jun. 17, 1997.
8 Patent Application Publication No. US 2004/0219488 A1 by Young-Wook
Choi et al., published Nov. 4, 2004.
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flank in the apical portion, and (b) the thread face of at least a portion of the
at least one thread is substantially flat. (Id. at 5-6.)
According to the Examiner, it would have been obvious to a person of
ordinary skill in the art at the time the invention was made to modify the
thread taught by Hansson with the thread angle and surface taught by
Fromovich “in order to get more condensation for soft bone.” (Id. at 6.)
Appellant asserts that the Examiner has not articulated reasoning with
some rational underpinning why one of skill in the art would have combined
the alleged features of Hansson and Fromovich to arrive at the implant of
Claim 1. (App. Br. 10.) In particular, Appellant asserts that “[t]he thread of
Hansson does not include a thread face (positioned between the coronal
flank and apical flank) having a length nor does the thread of Hansson have
a thread face length that generally increases from the coronal portion to the
apical portion.” (Id.)
After considering the evidence and the arguments, we agree with
Appellant that the Examiner has not established a prima facie case of
obviousness. In particular, we agree with Appellant that the Examiner’s
finding that Hansson disclosed an implant wherein the length of the thread
face is larger in the apical portion than the coronal portion is not supported
by the evidence. The Examiner relies on an annotated Figure 1 of Hansson,
reproduced below:
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Figure 1 of Hansson depicts a side view of the dental implant.
(Hansson, col. 5, l. 24.) The Examiner’s annotations indicate, among other
things, an apical flank, a coronal flank, the coronal portion, the apical
portion, a “thinner thread face” and a “thicker thread face.” (Final Rej. 11.)
According to the Examiner, Hansson depicts “the thread in the coronal
portion of the implant being smaller than the thread in the apical portion of
the implant . . . , therefore the connecting surface, i.e. the thread face, is
smaller in the coronal portion than the apical portion.” (Ans. 15.) We
disagree. Although the size of the apical flank and coronal flank are
increased in the apical portion of the implant, the thread face that defines a
length extending between the coronal flank and apical flank remains
essentially an edge, i.e., having a length extending between the coronal and
apical flanks of nearly zero (see, e.g., Spec. [0028]). Further, to the extent
that the Examiner also relies on Hansson Figures 6 and 7 (see Ans. 15) we
do not find these figures helpful as they depict the thread element height (h1,
h2) and crest-to-crest depth (d, 3d) and not the length of the thread face (see
Hansson, col. 6, l. 22-col. 7, l. 13.)
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Moreover, modifying Hansson’s thread with the thread face taught by
Fromovich, as proposed by the Examiner, does not cure this deficiency. The
Examiner relied on Fromovich Figure 6, reproduced below:

Figure 6 depicts a partial section taken from a cross-sectional view of
the Fromovich implant. (Fromovich [0063]-[0064].) As depicted in
Fromovich Figure 6, the length of the thread face (F) is larger in the coronal
portion (12) than in the apical portion (14), an arrangement that is the
opposite of what is instantly claimed.
Accordingly, we reverse the rejection of independent claim 1 and its
dependent claims 2-4 as being unpatentable over Hansson and Fromovich.
II. Claim 9
The Examiner found that Hansson taught a dental implant for
supporting a dental prosthesis as substantially claimed, except that Hansson
did not teach “the intermediate portion tapering inwardly at the first angle
and the apical portion tapering inwardly at the second angle wherein the first
angle is greater than the second angle.” (Ans. 9.)
The Examiner found that Schlapfer taught an implant wherein the
intermediate portion tapers inwardly at the first angle and the apical portion
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tapers inwardly at the second angle. (Id.) The Examiner found that while
Schlapfer does not teach that the first angle is greater than the second angle,
this parameter is a matter of design choice within the skill of the ordinary
artisan that may be obtained through routine experimentation in determining
optimum results. (Id.) Therefore, the Examiner concluded that it would
have been obvious to a person of ordinary skill in the art at the time the
invention was made to have modified Hansson’s implant to taper inwardly
as taught by Schlapfer, wherein the first angle is greater than the second to
provide an implant that may “be guided and centered easily.” (Id.)
Appellant contends that the Examiner is “merely picking and
choosing elements from the prior art using hindsight to meet the claimed
limitations.” (App. Br. 13.) Specifically, Appellant asserts that Hansson
teaches a dental implant with an intermediate cylindrical section that has a
constant diameter and that one of skill in the art at the time of the invention
would not have had any reason to change this shape. (Id. at 15.) According
to Appellant, a skilled artisan would not have been motivated to modify the
implant so that it may be guided and centered easily, as the Examiner
reasons, because “Hansson already discloses a conical apical section that can
serve to guide and center the implant.” (Id.)
We agree with Appellant that the Examiner has not established prima
facie obviousness. As Appellant asserts, Hansson provides an implant that
may be guided and centered easily. Indeed, Hansson states that its invention
“facilitat[es] its insertion into the bone tissue structure in the first place.”
(Hansson, col. 2, ll. 20-22.) Thus, we agree with Appellant that a person of
ordinary skill would not be motivated to modify Hansson’s implant to
provide a benefit that already exists.
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Further, claim 9 recites, in part,
[T]he threaded portion comprising a coronal portion, an
intermediate portion and an apical portion, the threaded portion
further comprising at least one thread extending from a root
surface, the at least one thread comprising a face that forms a
thread face surface,
in the intermediate portion of the threaded portion, the
root surface tapering inwardly at a first angle with respect to
the longitudinal axis,
in the apical portion of the threaded portion the root
surface tapering inwardly at a second angle with respect to the
longitudinal axis, the first angle being greater than the second
angle ….

(App. Br. 18, Claims App’x.) While the Examiner found that
Schlapfer’s Figure 1 depicts “an implant wherein the intermediate
portion 32 that tapers inwardly at a first angle and the apical portion 4
that tapers inwardly at the second angle,” the Examiner has not clearly
explained why these tapered portions are root surfaces, as required by
claim 9. (Ans. 9.) Nor do we find that Schlapfer teaches that these
portions represent root surfaces. (See, e.g., Schlapfer, col. 3, l. 39-
col. 4, l. 64.) Thus, even if combined, we do not find that the cited
references would have yielded the claimed invention.
Accordingly, we reverse the rejection of independent claim 9
and its dependent claims 10, 14, 19, and 22 as unpatentable over
Hansson and Schlapfer.
III. Claim 23
The Examiner found that Hansson taught a dental implant for
supporting a dental prosthesis as substantially claimed, including at least one
thread comprising a face extending between the coronal flank and apical
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flank, “wherein the thread face has a thickness that generally increases
[from] the coronal portion to the apical portion.” (Ans. 13.) However, the
Examiner found that Hansson did not teach “wherein at least in the apical
portion the face of the at least one thread is substantially flat.” (Id.)
The Examiner found that Choi taught a dental implant wherein, at
least in the apical portion, the face of the at least one thread is substantially
flat. (Id.) According to the Examiner, it would have been obvious to a
person of ordinary skill in the art at the time the invention was made to have
modified the screw thread taught by Hansson with the screw thread having a
flat surface, taught by Choi, to increase the surface area of the fixture portion
to form an advantageous structure for stress dispersion, as also taught by
Choi. (Id.)
Appellant contends, among other things, that Hansson’s implant does
not include a thread face having a thickness that generally increases from the
coronal portion to the apical portion. (App. Br. 16.) We agree. As
discussed regarding the rejection of claim 1, Hansson’s Figure 1 depicts an
increase in the size (i.e., length or thickness) of the apical flank and the
coronal flank in the apical portion of the implant, however, the thread face
remains the same, having a length extending between the coronal and apical
flanks of nearly zero. As the Examiner relied only on Hansson as teaching
the limitation of the thread face thickness generally increasing, the
combination of Choi and/or Cuilleron (claim 25) does not remedy this
deficiency.
Accordingly, we reverse the rejection of independent claim 23 and its
dependent claims 24 and 25 over combinations including Hansson and Choi.

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SUMMARY
We reverse each of the obviousness rejections.

REVERSED

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