Note: Descriptions are shown in the official language in which they were submitted.
1~5'~ 3 - :
This applicatlon is a division of Canadian S.N. 215,009, filed
ecember 2, 1974.
FIELD OF THE Il~VENTIO~
~:
This invention relates generally to both cosmetic and
structural restoration of teeth such as teeth that are badly
discolored, teeth that have been fractured or teeth that have
become cariously involved. More particularly, the invention
` relates to restoration of teeth by means of laminar overlay
where a desirably colored preformed facing of fully polymerized
::.
plastic material may be bonded to the enamel of the tooth to
provide teeth of pleasing cosmetic appearance or to provide
~- a fully restored properly shaped and properly colored tooth
.:
~ restoration. The invention also relates to laminar support ~ ~
~ .,,, :
- means for pontics in dental bridgework and for laminar splinting
; of periodontically involved teeth. `
BACKGROU~ID OF THE INVENTION
' Many phenomenon occur that have the adverse effect
~ .
~. of causing teeth to become badly discolored and in many cases,
, , .
teeth of children or adults become discolored during the formative
.. .: .
period or later. Some of the causes of tooth discoloration are
j ~ pharmaceutical discoloration that occurs when children are
,,,:.; : :
required to take certain drugs. Certain drugs have been known
, to cause the teeth of children to have various shades of yellow ~;
: .. .. . .
or brown if such drugs are taken before the permanent teeth of
; a child erupt. Discoloration also occurs due to the diet of
` persons that live in certain parts of the world, largely due to :
~ the minerals that are ingested along with the water that is
} consumed. The dental patient may also have a hyperplastic cond~
~ ~ tion where the enamel of the teetll does not fully develop, causing - ~`
., 30 the teeth to become easily discolored. ~ hyperplasti~c condition
, ~ .
,:
~` '
"
~ ` 2
i :
. :. . : : . .
`: ~
9~303
~` may also be evident, where the teeth of the patient may have an
excess of mineral salt deposit that causes the teeth of the
patient to have white spots. (Metabolic diseases such as those
releasing bile pigments or hemorrhagic disturbances that release
blood pigments may cause a discoloration o~ teeth. Bacteria ~;
frequently cause staining of teeth, e.g., green stain or
tobacco stain.)
~; Thus far, there has been no effective method of treat-
:. :: . . : - .
~ ing discolored teeth in order to give them a pleasing cosmetic ~
,, , . .: .
appearance. In the past, the only effective way the cosmetic
~;1 appearance of teeth could be improved is for the teeth to be
.. `:`'' capped with plastic or porcelain crowns. This is a very expensive
;` and time consuming procedure and the costs involved have the ~;
~',~ effect of eliminating cosmetic capping for all but a few
: .; . . . , ~
`` patients. Decorative inlays have also been employed in the
past but the difficulty of bonding materials to the enamel of
s teeth effectively prevent this procedure from being commercially
feasible in the practice of dentistry.
When teeth become fractured or cariously involved, it
. ` 20 frequently becomes necessary to restore the teeth to their proper `~
shape and appearance to promote proper incisive and masticatory
function and for cosmetic purposes. If a tooth has become
fractured and restoration is desirable, in the past restoration
~? ~.,, ' : .
has been accomplished by application of crowns to the teeth,
which crowns have been composed of metal materials such as gold
;.~. . ~ . :and plastic materials, such as methyl methacrylate polymer. An
acceptable restoration has been accomplished in the past by
; application of jacket crowns to the teeth and by application of
, . .
~ porcelain that is fused to gold crowns. These crowns typically ;~ ~
:, , :
, ~ 3
~; ', ''
~LOS~303
;; ' . ,` , involve a great deal of expense and also involve a great deal
~;; of dental chair time for application. For example, restoration
of teeth by application of gold crowns may cost in the order
~ of $200 to $225 and may require as much as three hours chair time
.~ !
~, ~ in order to completa the installation of each c~ow~.
A primary disadvantage in the application of crown
~-~ restorations to teeth is the requirement that the tooth be pre~
shaped to the drastic degree in order that the crown may be
.:
properly applied thereto. For proper application of crowns
it is necessary that the crown and the tooth be prepared in
order to achieve resistance as retention of the crown. The
crown, in a proper applicationj is retained in position on the
tooth by proper fitting to provide resistance and retention and
the presence of crown cement between the prepared tooth and the
crown is primarily for the purpose of filling aliy voids that might
exist and thereby prevent debris from becoming deposited in the
voids between the crown and the prepared tooth. The cèment ~ ~
disposed between the crown and the tooth, although providing a ~ --
i :. -
~ gripping function to some degree, does not provide the primary
i;:. .;-, ~ .
gripping function that retains the crown in physical assembly
v,~ ~ with a tooth structure. One reason for this is the fact that
~ ; the cements that have been used in the past for cementing crowns
., . ~
`~ , to prepared teeth, during crown restoration of the teeth, is a
~;~ water soluble material and in time, if a crack or fissure is
.... ...
present between the tooth and the crown, saliva will penetrate
the joint between the crown and the tooth and dissolve the
;~ - cement. If proper resistance and retention were not provided
~: ? ::
h between the crown and the tooth, the crown would become
~, separated quite readily from the tooth structure.
,.;~, ,' .
'~' ' ' ' ' .
."~ : . ' ' :
' ~, ' . I ' '
.~'; ~' .
1~598~
A more recently utilized method of -tootll restoration
has been utilized that is effective in restora-tion of
fractured teeth as well as teeth that have developed caries.
After etching of the teeth with an acid solution, such as 50%
; to 75% phosphoric acid or citric acid for a short period of
time, for the purpose of removing mineral salts from the
~; enamel surface and creating spaces or "micro pores" in the - -
-
- enamel where the mineral salts have been dissolved by the acid,
a dental sealant material may be applied to the acid prepared
enamel surface which sealant enters the micro pores and when
,:
polymerized, forms an intimate mechanical bond with the enamel
surface of the tooth. The dental sealer material may be of the
type that is produced by the reaction product of Bisphenol A -
: ~;
and Glycidyl Methacrylate such as a product manufactured and
sold under the trademark of Nuva-Seal by the Caulk Division of
Dentsply International, Inc. of Millford, Delaware. The
: ~, .
sealant product, referred to as "Nuva-Seal", is activated by
Benzoin methyl ~ther ca~alyst prior to application thereof to a
: ., .
`~ tooth surface and is polymerized after application to the
-: ~
~ 20 surface by exposure to ultra-violet light.
::- :. ,~ :
~ After application of the sealant material to the
-. -, .. ~ - .
i~ ` prepared enamel surface o the tooth, a dental filler material
,,,.,. ~ ,.
may be applied to the prepared and sealed surface and may be
shaped essentially to the original configuration of the tooth
~-~ with a plastic shaping instrument. The dental filler matcrial
. ~ .
. "
may also be of a character that is based upon the reaction ;~
product of Bisphenol A and Glycidyl Methacrylate which is also
,,.,.
activated by Benzoin methyl ether catalyst and selectively
polymerized by exposure to ultra-violet light. ~ de~tal filler
~ ~ .
, .. . .
:: .
,,~ " ' '
:
: ', , - : ' ' . ~ ' :: : . '
.:
: ~ ~ : " :; : , . :: :
~05~ 3
material that is suitable for this purpose is sold by the
` Caulk ~ivision of Dentsply International, Inc. under the
trademark "Nuva-~il". This material ~ill not become polymclized
until it is selectively exposed to ultra-violet light. The
material, therefore, may be worked for whatever period of
;~ time is necessary to properly shape the tooth restoration to
. . .; ,
its desired physical characteristics and polymerization will~
occur in a few seconds time after application of ultra-violet -
light to the shaped material. After the dental filler material
.. .
'~ 10 has been shaped and polymerized, the outer surface of the filler --
~ material and a portion of the exposed enamel at the marginal
~ . , .
portions of the filler material may be finally shaped with ~ -
appropriate sanding or grinding instruments and a coating of
dental sealer material may be then applied to desirable portions
of the restored tooth and may be subsequently polymerized by
appllcation of ultra-violet light.
Although excellent tooth restorations may be
accomplished by the above noted use of ultra-violet light
polymerized dental sealer and filler material, it is very
difficult to achieve precise color matching of the restored
tooth to the color of adjacent teeth. The restoration process
therefore ls often less than desirable from aesthetic stand- `
,: ,,, ~.
point. The dental filler and sealer material is commercially
produced in a few different shades in order that color matching
may be accomplished as nearly as possible, but it ls well known
that wide variation in color and tooth appearance is found in
the teeth of dental patients. It is virtually impossible to
select from the few shades of materials that are available a
material that is capable of precisely matchin~ witll the color
, :
and appearance of adjacent tooth if color matchin~ is indeed
desirable.
~' ':' '
.; : . .
~598~3 . ~-
..
;~, , . `.' ~
.
In many cases, it is not desirable to match the
tooth restoration material with the adjacent teeth, especially
when the patients natural teeth have become discolored to the
point that the cosmetic appearance is undesirable.
In the event one or more teeth should be missing,
it is typically necessary to employ a dental bridge wherein a
dental prothesis is connected to teeth adjacent the opening
produced by the missiny tooth and an artificial tooth or pontic
forming a part of the prothesis is supported in the space to
prevent migration of the adjacent teeth. In view o the fact
that bridge work may not be supported by the enamel of abutment
teeth adjacent an opening, it is typically necessary to provide
the adjacent teeth with crown restorations even though these
teeth may be perfectly normal. The crowns may be provided `-
with appropriate means for physical attachment of the bridge
work in ordex to support the bridge work prothesis. It is, ' `
of course, undesirable to provide crown restorations for
perfectly normal teeth, although in some cases this is i~
necessary to avoid the problems that may occur by migration of
teeth by absence of one or more of the patient's permanent
teeth. It is desirable, therefore, to provide means for
preparing the abutment teeth adjacent an opening caused by a
missing tooth or teeth with means for positively securing a
prothesis bridge work in place without necessitating the tooth
preparation that is necessitated by application o bridga work
' ,
support cro~ns.
..... : .. .
" -,::- .,
,, ,: .... . .
~ 7 -
5~1!36)3
S~MMARY_OF THE INVENTION
.
Although there are various apsects of the
invention disclosed, one aspect of the present invention
is to provide a novel preformed fully polymerized laminant
that may be effectively bonded to the enamel surface of a
patient's teeth for the purpose of im~roving the cosmetic `~
appearance of the teeth and for the purpose of providing- ~ -~
eficient low cost, cosmetically pleasing tooth restorations.
It is another feature of the present invention to
provide anchor means for dental brldge work prothesis with~
~`~ out necessitating grinding away of abutment teeth adjacent
to an opening caused by a missing tooth or teeth that
~otherwise must be necessary in order to provide prothesis
' anchor crowns on the abutment teeth supporting the bridge
:1~ ' work-
~ In one aspect the invention in this divisional
'";13 application comprehends dental bridge work apparatus compris~
;i ing a pontic formed of dental restoration material and
adapted to be disposed in the space defined between abutment
20 ~ teeth, and at least a pair of laminar facings being connected
one on either side of the pontic and supporting the pontic,
the facings conforming to at least the labial surfaces of
~- the abutment teeth.
`~ Another aspect of the invention in this divisional
~ application pertains to a laminar tooth restoration element ~ ;;
`~^ adapted to be bonded to the enamel surface of at least one
, i ,: ; :-
~ ` of a patient's teeth. The tooth restoration element
i ~ includes a body of dental restoration material being pre~
formed to conform to desirable body portions of the outer
:: .:, ~ : ,
5g8~3~ ~
enamel surface of the teeth to which it is to be bonded,
and being of such color to provide a completed too-th
restoration of pleasiny cosmetic appearance. The body
defines a pair of abutment facings adapted to be bonded to
,~ . . ,
the labial surfaces of abutment teeth disposed on either side
of a tooth space created by a missing tooth or teeth. A
pontic is connected to each of the abutment facings and
is suppor-ted b~ the abutment facings within the space.
Other and further aspects, advantages and features ;
of the present invention will become apparent to one skilled
in the art upon consideration thereof. The form of the
invention, which will now be described in detail, illustrates
the general principles of the invention, but it is to be ; ~ ;
understood that this detailed description is not to be
taken as limiting the scope of the present invention.
~, Briefly there is disclosed a method and materials
~' Eor restoring badly discolored, fractured or cariously involved
teeth, wherein the method includes selection of a preformed
fully polymerized plastic lamination or facing that may be
composed of a suitable plastic material and which may be
selected according to color and physical appearance
,.. . . .
in order to provide teeth of pleasing aesthetic appearance. `~
The preformed facing or lamination may be further -
modified by shaping or grinding in order to fit the
. ;, ~ :
configuration of the tooth being restored as precisely as ~;
$ ~
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` ~59803
: :
possible. After the color, shape and physical characteristics
of the tooth have been matched as desired and after the facing
has been preshaped to fit the tooth being restored, the enamel
::
- surface of the tooth to be restored may be etched with an acid
:::
`~ material, such as a solution of 75% phosphoric acid, for a sufficient
. .
period of time to prepare the appropriate enamel surface of the
`~
tooth for reception of a dental sealant material that may be
.. : .
polymerized in place. The inside surface of a plastic facing to
be secured to the tooth to be restored may also be coated with
. :,::
. ~ .....
~ ~ 10 a thin coating of the same dental sealant material which material
: ;.
may be polymerized in any suitable manner. A coating of a dental
, . ..
'~ filler material that may be subsequently polymerized may then be
. :~
applied to the tooth to be restored or to the facing to be bonded ~-
, ~ to the tooth and the facing may be applied to the tooth in such
manner as to squeeze out any excess dental filler material, thus
~;- ;: '
filling all of the voids between the tooth and the facing with
the iller material. A small amount of the dentaI material
existing at the marginal edges of the facing may be smoothed
~` about the marginal edges in order to provide a smooth contour at
the joint between the edges of the facing and the enamel surface
of the tooth. After inspection of the tooth to insure that the
.
.~ color and physical characteristics of the facing exactly match ;~
;,. ~ .
~;~` the color and physical characteristics of adjacent teeth, the
filler material may be selectively polymerized in place, where
it is rendered from a paste or putty-like consistency to a hard
porcelain-like durable consistenry. The dental sealant material
: .
~ j and~the dental filler material may-both be composed of a
~,.....
~- compound that will remain unpolymerized or uncured for a relatively
indefinite period of time and which may be subsequently polymerized
in a few seconds time by application of ultra-violet li~ht thereto.
'
`~ - 1 0
.: ~05~803
,,
.,.
The dental filler material may also be of the type that is
... . .
premixed prior to application thereof to the teeth of the patient
- and which is allowed to become polymerized in place following a
: ~.. , ~ .
predetermined curing period.
~; BRIEF DESCRIPTIO~I OF THE DR~WINGS . . :.
So that the manner in which the above recited features,
advantages and objects of the present invention, as well as others,
which will become apparent, are attained and can be understood
:' :,: . - :. . -
in detail, more particular description of the invention, briefly
` ~ 10 summarized above, may be had by the reference to the embodiments
thereof which are illustrated in the appended drawings, which
drawings form a part of this specification.
`` - It is to be noted however that the appended drawings
illustrate only typical tooth restorations that are made possible
by employment of the method and materials set forth herein and
are therefore not to be considered limiting of its scope, for the
` invention may admit to other equally effective embodiments. ,
...:.
~'`'.,' ~
~' ~ In the Drawin~:
. :,....................................................................... .
: `- Fig. 1 is a side elevational view of an anterior
20 tooth having a portion of the enamel thereof shown in section -
and showing a preformed plastic facing that has been applied to
the labial and incisal portions of the tooth in accordance with
:,.
' the present method.
Figs. 2A - 2D are illustrations of some of the
s various tooth restorations that are possible through employment ;~
of the present invention.
,t, . ..
,'.'. ,.`. , ` , 5
''.; `~ ' ~ ;-
~, :,
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~5~ 3
Fig. 3 is a view showil)g the upper teeth o~ a patient and
depicting a dental bridge prothesis including lamina preparation of
teeth that support the bridge prothesis in operative position.
. . ~. .
Fig~ 4 is a partial elevational view of the bridge work
-j prothesis illustrated in Fig. 3 illustrating the outward appearance
of a completed bridge installation
, ,., , . :
Fig. 5 is an end view of the upper incisor teeth of a
patient illustrating periodontal splinting of the patient's tceth
5 .`'
and showing the relationship of the laminar splint structure to
the tooth structure of the patient's teeth.
.. . .
DESCRIPTION OF PREFERRED EMBODIMENTS
Now re~erring to the ~rawings and first to Fig. 1 a tooth
i,: ~,.
structure is illustrated generally at 10, which tooth is an an~
terior incisor having a fractured incisal portion. The exposed
crown portion 12 of the tooth is shown as having a laminar plastic
res~oration applied thereto ~hich laminar restoration also includes
a lower incisal portion to restore the racture of the tootll. A
portion o the root 14 of the tooth is sho~n positioned relative to
gum tissue surrounded thereabout~
Assuming that the tooth 10 has a fractured incisal portion
as shown and perhaps that the labial surface of the enamel is badly
discolored or that perhaps the incisal or labial lingual or proxi-
mal portions of the tooth may be cariously involved to the point ;
that partial restoration is desirable, according to the method
of the present invention, a restoration technique may be employed
wherein a preformed plastic facing 18 may be bonded to the en-
,~
~ amel portion 20 of the tooth structure. It is not necessary,
,",
~- - 12 -
,i': :., ~ o : ,
as in the past, to grind away the tooth structure and expose the
dentin shown in broken line at 22 unless the presen~e of cari~s
necessitates such actlvity. In fact, it is not necessary to
remove any major portion ~f the tooth structure to achieve
complete restoration of the tooth.
- It may be desirable to prepare a very small portion of
the exposed surface of the enamel in order to remove undesirab'e
mineral deposits that might interfere with the bonding process.
This may be accomplished by very light sanding. Desired portions
of the exposed enamel then may be prepared for bonding by appli~
c . cation of a suitable acid material for a short period of time.
This is known as acid etching, a process that creates spaces or
.. :~ . . .
` ~ "micropores" within the surface layer of enamel which will allow
a dental sealant material to penetrate into the surface of the
enamel itself and establish an efficient mechanical interlocking
bond with the enamel. As the tooth is etched, projections,
which may be referred to as "rods" or "tags" are developed ~ ,~
: i
which increase the physical bonding of the sealant to the
tooth structure. The employment o acidic conditioning agents
` , 20 has an effect on the tooth enamel that removes at least a
f' ` " .
"' ';
~`A` portion of the mineral salts from the enamel surface to a very
i-i shallow depth, i.e., in the order of 25 microns, thereby creating `~
i spaces or micropores in the enamel where the mineral salts have
; . ,................................................................... .::
: been dissolved. Etching of the tooth enamel, although initially ~
...... .
~ creating a dull appearance on the enamel surface does not ~ ~
, ~
constitute permanent alteration of the enamel surface of the
tooth. In fact, areas of enamel surface that are etched, if not
covered by a coating of dental sealant material, will return to
its normal translucency within a few days. It is t~e~orized that
!
acid etched enamel is remineralize~ by the disposition of
calcium phosphate salts from the saliva. Other than the creation
- 13 -
, . . . .
f`~ :
59810~
of a superficial etch, there appears to be no detrimental
effect to the tooth tissue.
After acid etching of desirabIe portions of the
~ enamel of the tooth, the acid etched enamel is maintained clear
;~ of any material such as water, oil, saliva that~might interfere
~;~` with the bonding process and a dental sealant material is applied
thereto and is allowed to subsequently become catalyzed in place
~` in order to seal the micropores that have been established by
the etching process and to establish the physical surface to which ;
a plastic lamination may be effectively bonded. Although the
dental sealant material may take any suitable form within the
spirit and scope of the present invention, it may be desirable
to employ a dental sealant material such as that sold under the ;~
trademark Nuva-Seal by the Caulk Division of Dentsply -
. International, Inc., mentioned hereirlabove, and referred to
` hereinafter merely as sealant. The sealant is a very "wet"
~'`,''~ , , ,
:,t`, " ~ material that will readily penetrate the minute interstices or
micropores that are developed on the enamel surface during the
etching process. After application of the coating 24 to the
.`';'.J~ 2 0 prepared surface portions of the tooth enamel, a coating 26 of
~" ~ slmilar sealant material may be applied to the inside surface
psrtion of the preformed plastic ~acing 18. The surface coatings ^~
of both the tooth and the facing may be then polymerized, which
~,:; c
: in the case of Nuva-Seal dental sealant is accomplished by
means of exposure to ultra-~iolet light after having been
~; previously activated b~ Benzoin methyl ether catalyst in the
manner discussed above. ~;~
j After the coatings 24 and 26 of the enamel an~l facing,
respectively, have become catalyzed, hardening the~sealant
:S~
~' .'
~[35~ 3~ `:
material to a porcelain-like quality, a quanti'ty 28 of a
dental filler rnaterial may be applied ,ci-ther to the facing 18
or to the prepared and coated portion 24 of the tOOtll enamel
and the plastic facing material may be brought into intimate
contact with the tooth structure. It is desirable that the
dental filler material be capable of controlled polymerization
or curing in order that it may be inspected for physical shape
and cosmetic appearance and approved before it is permanently
bonded to the tooth structure. If during inspection, it is found
, 10 hat the preformed facing 18 is of undesirable color
characteristics and does not precisely match, with adjacent teeth
or~with exposed portions of the tooth being restored, it will ~,`
. ~ . , ",
,',;~ be desirable to simply remove the pre:Eormed facing and substitute
a facing of proper color and shape. Ordinarily,,the facing
', material will be emplaced prior to application of coatings to - ~`~
`, the tooth structure in order that the color characteristics of
i, the facing may be precisely matched w:ith adjacent teeth. ~ '~
,.~, After the preformed facing has been installed in ~'
proper position, it is tightly pressed to the tooth structure
20 and excessive dental filler material is squeezed out about the ~
' marginal edges of the facing material. All of the voids ' -~ -
~ between the external tooth structure and the internal surface of
,`'~ the facing material will be filled with the dental filler
: :-
- material thereby establishing proper structural integrity of the
restoration. Most of the excessive filler material that has
.: - .
''' been squeezed from between the tooth and facing is removed and a ,'
'' small portion of the filler material may be molded ab,out the ~ '~
: , : --
joint established between the marginal edge of the facing material
:, .
'~ and the adjacent enamel portion of the tooth. A!ftèr'this has
;.,.:, . . ~ :
, - 15 - ~ ~
~, ,2V~ ':
:,
~ 59~)3
~'
been done and the physical shape of the restoration has been
approved, the dental filler material may be polymerized, thereby
causing it to harden to a very hard porcelain-like characteristic.
Following polymerization of the dental filler
material, the preformed plastic facing and the tooth enamel
~ `surface adjacent the marginal edges of the facing may be sanded
or ground lightly in order to ensure a smooth and continuous
restored tooth surface. Restoration then may be completed by
application of a coating of dental sealant material to the
exposed surfaces of the preformed plastic facing and the tooth ~
enamel adjacent the marginal edges of the facing. The outer ~"
coating 30 of dental sealant material then may be polymerized ln
any suitable manner thereby achieving a completed restoration
having~the glossy outer appearance of the natural enamel
surface of the restored -tooth and havin~ color characteristics
that precisely correspond to the color characteristics of
adjacent teeth.
.; .
~, :
~ If either the filier or sealant materials are premixed
,. j ~
and become polymerized after a predetermined limit peri.od of
` time, it will be necessary of course, to insure that the tooth
: ~,
restoration is properly colored, is properly emplaced and shaped
before the curing or polymerization period ends. Use of sucl~
.. :
- materials is within the spirit and scope of the present invention.
The preformed plastic facing or lamination that is to
be applied to the teeth during restoration according to the -
method set forth herein may conveniently take any suitable form
that is suitable for tooth restoration. It has been found
.:. ,
through initial tests that a plastic material such as fully
polymerizcd, preformed methyl methacrylate is a suita~le material
~0 for tooth restoration in accordance with the te~chin~s o~ the
present invention. Methyl methacrylate is utilized presently in
- 16 -
.
,
, '
~ ~S98~3~ ~
the manufacture of denture teeth and therefore corresponds very
closely to the appearance and functional capabilities of natural
teeth. It is envisioned that the plastic facings may be pre-
manufactured according to various shapes, forms, colors, contour
and the type of restoration desired, whether thé restoration be
complete crown coverage or whether the restoration be of minimal ~-
nature such as for restoring a fracture of an incisal edge of a
tooth. Plastic facings or laminations may also be provided for
restoration of proximal caries. In most cases the marginal -
edges of the preformed plastic facings would be of knife edged ~
. . . , ~ , .configuration in order to establish a smooth contiguous surface
of~the joint between the enamei and'the laminant facing. ~ '
'~ The plastic facings, if desired, may be composed of
';~ very thin and flexible material that rnay be readily molded '~
~l by application o~ mecih~nical pressure thereby causing the
' flexlble facing to conform to the tooi:h surface that is to be ;
Y restored. For example, it may be desirable to provide a flexible
i-'Y . ',~
and moldable plastic facing that may be molded to conform to
selected surfaces of the tooth. For example, a~thin and flexible
... :. : .-
facing may cover the labial surface of the tooth and may cover
one or more of the proximal edges. After applying the bonding .~ -~
' ~ agent to the tooth surface or to the facing, the facing may '~ '
'~ simply be emplaced and formed to conform to the;configuration
of the tooth. The bonding agent may then be selectively ''~
polymerized by application of ultra-violet light or by any ~'
other suitable means to achieve a proper bond between the ~'
$ ~;
-~' facing and the tooth. Also, if desired, the facing and ;~
' the etched surace of the tooth, may'be provided with a thin ~'
., . .~ ~. .
coating of dental sealant that is allowed to harde'n''i`n place ~'
! 30 either responsive to application of ultra-violet li~ht or by
- ~ ' any other suitable mcans of activation.
l~ - 17 -
.,i '~
.:, ,:- , , ~ . . ~ . ~ , . ; .
: .: . :., , : , . . ::. : , ~ .. .: : :
~sg8~3
With reference now to Figs. 3 and 4, in accordance
with the teachings of the present invention, simple and
efficient bridge ~ork may be accomplished without necessitating
provision of abutment crowns on abutment teeth adjacent a missing
tooth opening within which a pontic is to be disposed. As
` ~illustrated in Fig. 3, a number of permanent teeth of a patient
are depicted pictorially and a pontic 34 is substituted for a
missing natural tooth. The pontic 34 is shown to be disposed
` between abutment teeth 36 and 38. As was mentioned herein-
above, ordinarily it is necessary, in order to support the
pontic 34 in place between the abutment teeth, to provide the
abutment teeth with abutment or bridge support crowns. In
;; - ,. ;, ~
;~ order to accomplish this, the abutment teeth 36 and 38 must
ordinarily be reshaped by grinding to prepare the teeth for
reception of abutment crowns and, of course, such reshaping
permanently distorts the normal configuration of the teeth.
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~59~03
In accordance with the present invention, it is not
necessary to reshape the abutment teeth 36 and 38 or make
impressions, it being only necessary to prepare the anterior
enamel surface of the abutment teeth for efficient bonding of
; bridge support laminations thereto~ In accorda~ce with the
:. . -
present invention, the pontic 34 will be formed integrally with
~- or connected to support facing elements 40 and 42, the inner,
~` surface of which may be prepared in the same manner as discussed
above in connection with preparation of the plastic facing 18
, - 10 depicted in Fig. 1.
;' After application and polymerization of the coating
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of sealant to both the inside surfaces of the plastic laminar ~ -
facings 40 and 42, the labial surfaces of the abutment teeth 36
;~ and 38 may be etched with a solution of phosphoric acid or ~ith
any other suitable etching material that provides a microporous
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`, enamel surface on the abutment teeth. A coating of dental sealant ~
: ~ ,; ., . :
may then be applied to the abutment teeth and may be subsequently ~ ,
polymerized. Dental filler material then may be applied ~`
either to the inside surfaces of the laminar support facings 40 -~
and 42 or to the prepared and coated labial surfaces of the
~ . :,?
i'l abutment teeth 36 and 38 and the pontic may then be positioned ;~ ~
;~ by positioning of the laminar facings 40 and 42 into intimate ~ `
engaging assembly with the prepared surfaces of the abutment `-
teeth 36 and 38. Sufficient pressure is then applied to the
:.: ,. - ~ ~ :
facings 40 and 42 to squeeze out excess dental filler material.
;~ A portion of the excess dental material is then molded about the
`~1 joint created between the mar~inal edges o~ the respective
facings and the prepared and coated enamel surfaces of the
abutment teeth to provide a smooth contiguous surfac~ at the joint.
. ... ' . ~ ~'~:
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~la3598613
After the pontic and the facings have been emplaced
in the manner illustrated in Figs. 3 and 4, the bridge work
will have its final appeaxance and can be inspected both by
the patient and by the de-ntist for determination if the
appearance is cosmetically pleasing. After acceptance, the ~ ;
dental filler matsrial then may be selectively polymerized in
any suitable manner, such as by application of ultra-violet
light, for example, thereby completing the bond between the
facing and the tooth and ensuring that all voids that might
exist between the facing and the adjacent abutment teeth~are -
completely filled with dental filler material. After hardening
of the dental filler material, desirable portions of the ; ~
abutment ~eeth, facings and perhaps also the pontic may be ~ ~`
lightly sanded or abraded with pumice to eliminate any ;~ ~
irregularities in the exposed surfaces of the facings, the - ~ ;
abutment teeth and the pontic and to prepare these surfaces for
a coating of dental sealant material that is subsequently
.
applied. The dental sealer material, after being applied will
have a very glossy finish and when subsequently polymerized,
such as by application of ultra-violet light thereto, will provide
a bridge work that conforms as precisely as possible to the
appearance of the patient's other teeth, if in fact such
conformance is indeed desirable. Where the remaining teeth of
, , ,
the patient are discolored or cariously involved, it may be ;
appropriate to also provide certain ones of the patientls teeth
with laminar facings as discussed above in connection with
Fig. 1 for enhancing the cosmetic appearance of the patient's
teeth.
Referring particularly to Fig. 4, the po~tic 3~ will
be physically connected or formed integrally with t}lC adjacent
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~OS~8~3
facings 36 and 38 a-t the typical tooth contact areas 44 and 46.
The anterior portions of the pontic and the adjacent facin~s will
be of such configuration that the appearance of tooth separation
will be given. The anterior facing and pontic structure will
make effective use of shadows to enhance the appearance of tooth
separation and embrasures 48 and 50 will appear between the
acings and pontic and below the gum line 52. The bridge
` work prothesis, therefore, will have a natural appearance and it
will not be necessary to modiy the abutment teeth by crowning
10 in order to provide proper support for the pontic. If it
subsequently becomes desirable to remove the pontic, this may
be done very simply and efficiently and the abutment teeth 36 ~ i
and 38 may, if desired, be returned to the original condition
thereof simply by effective removal o the facing material
3 therefrom. If desired, the facing material may simply be
~ removed by grinding and polishing thereby exposing the original ~ `
,~ .
`~ enamel surface of the abutment teeth.
;3 With reference now to Fig. S, it may be desirable to
~ establish periodontic splinting between one or more teeth, if a ~-
'1 , . .
3:: 20 tooth needs to be physically supported by another tooth.
Ordinarily/ when periodontically involved teeth are splinted ~ -
`J together, it is necessary to provide both of the teeth with ;
appropriate splinting crowns and to secure the crowns together
~ by appropriate bonding or by other physical means. Fig. 5
- discloses a pair of teeth that have been splinted together by
-~ means of laminar plastic facings that are either integrally
-~ formed or bonded together at the contact points of thë teeth. ' ~;~
Here again, the facings and the teeth to be splinted will be
~ prepared by acid etching and coating in the same manner as
: '
21
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~L~5~3
discussed above in connection with Fig. 1. The plastic laminar
facings 54 and 56, which are joined together at the contact
point 58, are applied to the teeth with dental filler material
and dental sealant in the-same manner as discussed above. The
material from which the facings are composed may be appropriately
colored to match the adjacent teeth or may be colored as
desired for pleasing cosmetic appearance. Moreover, it is not
necessary to grind away the major portion of each of the teeth
in order to provide splinting crowns that will secure the
teeth together. In the event it is subsequently desirable to
eliminate the physical support between the teeth it may be
simply desirable to separate them at the contact points or in
the àlternative, the facing material may be removed from the
~eeth in any suitable manner thereby e~posing the original
enamel surface of the teeth. ~ `
Figs. 2a, 2b, 2c and 2d illustrate a few of the many
possible tooth restorations that are possible according to the
teachings of the present invention. For example, in Fig. 2a
i .
the tooth has a fractured incisal edge, as shown in broken line.
; 20 The facing applied to the labial surface of the tooth would
` therefore be provided with a thin labial portion covering the -
labial surface of the tooth and a relatively thick incisal portion
would be formed integrally with the thin labial portion. The
:; . : - .
thin labial portion, in addition to covering the labial surface ~ -
of the tooth and providing a pleasing cosmetic appearance thereto,
;..................... . .
; will also lend strength to the labial portion of the restoration.
Fig. 2b depicts a tooth wherein the restoration facing
includes a pair of proximal portions and an incisal portion formed
integrally with a thin labial portion thereby provi~dlng proximal
restoration such as would be required in the event of proximal
,' ` ' , ' .
22
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~S19~03 :
caries. The laminar facing, in this case, will be provided with
a pair of proximal portions that may both be utilized, if desirable.
One of the proximal portions may be readily removed from the
~acing in the event only one proximal portion is desired. Fig.
2c illustrates a tooth in side view, being provided with a facing
having a proximal edge portion.
Fig. 2d shows a tooth restoration wherein the tooth
is fully covered with a thin crown overlay covering the labial,
~ incisal, proximal and lingual portions of the tooth. `~
,... . .
It is practical to assume that cosmetic facings and
plastic tooth restorations may become unsatisfactory in
appearance or function after a logical period of effective use.
It is also logical to assume that in a small number of cases
the plastic facings or restorations may become chipped, broken,
worn or detached and may need replacement. When replacement is -~
~ necessary, it is simply appropriate to restore the tooth
;~ involved to the original form thereof by removal of the plastic
. -. .
material and thereby exposing the original enamel surface of
the tooth. The process for installation of cosmetic facings -
and plastic restorations may simply be repeated without any ;
..
structural damage to the tooth that is treated in this manner.
It may be desirable to remove only part of the facing material
to accomplish restoration because a plastic to plastic bond may
be readily accomplished. Restoration of fractured, cariously
involved or badly discolored teeth may be accomplished at
minimal cost through employment of low cost materials and through
conservation of dental chair time for such treatment. Through ; -~
employment of the invention in practice, dental bridge work and
splinting of periodontically involved teeth may also`be
; ~
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23
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~LIP59~ 3
effectively accomplished at very low cost. Moreover, it will
not be necessaxy to alter abutment teeth or to provide crowns
for periodontic splinting because the facing material itself
will be of sufficient structural integrity for support of pontics
and for the establishment of supporting connections between
splinted teeth. One of the most important aspects of the present ~ -
invention is the fact that there is no need whatever for permanently
.:
altering the physical structure of teeth either for the accomplish- -~
ment of cosmetic facing or for preparation of support crowns as
in the case of bridge work or periodontic splinting and the teeth
may be returned to their original condition simply by removal of
the facing material therefrom.
Where the teeth of a patient have become severely
discolored or cariously involved such as frequently occurs when
a patient lives in certain parts of the world, the teeth can be
. ~ . .
~` treated very simply and efficiently and at minimum cost in order -
., ~ .
; to provide the teeth with a pleasing cosmetic appearance.
~i During the process of installation of facings for cosmetic
: . ' " :''
appearance, after the facings have been attached to the teeth
~; 20 and before the bonding material has become polymerized, the
,:.. ~ . . ,.: :
facings may be inspected for cosmetic appearance and if ; ~;~
unacceptable, may be simply and efficiently removed and other
facings may be substituted therefor. The plastic facings both
for cosmetic improvement of the teeth and for restoration of
fractures or carious deformation may be readily accomplished
without necessitating the use of anesthesia to prepare the
patient for treatment.
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lL~5~03
It is therefore apparent that the present invention
is one well adapted to attain all of the objects and advantages
- hereinabove set forth, together with other advantages which
will become obvious and inherent from a description of the ~'
method and materials utilized according to the teachings of
~; the invention. It will be understood that certain combinations
and subcombinations are of utility and may be employed without
;~ reference to other features and subcombinations. This is
contemplated by and is within the scope of the present inven-
tion.
~ As many possible embodiments may be made of this
;;~ invention without departing from the spirit or scope thereof,
it is to be understood that all matters hereinabove set forth
,~ or shown in the accompanying drawings are to be interpreted as
`~ illustrative and not in a limiting sense.
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