A permanent dental bridge comprised entirely of one or more types of dental composite material may be constructed directly, i.e., without laboratory assistance, either in situ or ex situ, without reduction of the abutment teeth. The direct composite bridge comprises one or more composite pontics, integrally laminated attachment portions and substructure, and optional embedded reinforcement materials. In the in situ process, composite material is applied between abutment teeth in the patient's mouth, attachment portions are formed from the composite material, those attachment portions respectively attaching to corresponding surfaces on the abutment teeth, and the composite material is cured. The steps of application and curing of composite material are successively repeated until a completed dental bridge, including a pontic portion, is formed entirely within the patient's mouth. The ex situ process is accomplished by fabricating a composite pontic, applying composite material between the patient's abutment teeth, curing the composite material, applying a lamination of additional composite material between the abutment teeth, inserting the composite pontic into the lamination, and curing the lamination. In either process, a gingival stent can be utilized to act as a platform upon which the successive composite laminations may be formed and also, if employed immediately following tooth extraction, to act as a bandage. The stent is inserted into the patient's mouth before application of composite material between the abutment teeth, and is removed after formation of the completed bridge but prior to the contouring and finishing thereof. In either process, one or more reinforcement materials (including different types of dental composite) may be introduced in laminations between the abutment teeth for reinforcement.

BACKGROUND OF THE INVENTION
 1. Field of the Invention
 The invention is concerned with, generally, the domain of restorative and
 prosthetic dentistry, specifically, "fixed partial dentures," more
 commonly known as "fixed dental bridgework." The traditional or "indirect"
 method of producing fixed dental bridgework typically involves the
 extra-oral, or outside the patient's mouth, use of molds, metal
 frameworks, and pressurized ovens to produce bridgework. The "direct"
 method of producing fixed dental bridgework is done in situ, intraorally,
 entirely within the patient's mouth using particle-filled dental
 restorative resin (called "dental composite" or simply "composite"), and
 plain dental restorative resin, without reduction of the abutment teeth or
 the use of cement or luting agents.
 2. Description of Related Art
 Fixed dental bridgework has traditionally involved the following process:
 (1) during the first office visit by the patient, the dentist surgically
 reduces the anchor or "abutment" teeth on either side of a space
 (edentulous area) in a dental arch to be spanned by the bridgework; (2)
 the dentist makes an impression of the reduced abutment teeth and
 edentulous area; (3) the impression is sent to a laboratory for
 construction of a model to which the bridgework is conformed during
 fabrication; (4) metal "pontic" castings, a metal framework that holds the
 pontics (artificial teeth), and attachment wings are fabricated; (5) in a
 special high temperature oven, porcelain may then be fused to the pontic
 forms, and to the metal attachment wings on each end of the metal bridge
 framework if desired, depending on the original bridgework design; (6) the
 bridgework is sent from the laboratory to the dentist, (7) during a second
 office visit by the patient, the dentist inserts and adjusts the
 bridgework in the patient's mouth; and (8) the dentist "permanently"
 cements the attachment wings or crowns on the ends of the bridgework to
 abutment teeth to fix the bridgework in place. Examples lo of the type of
 bridgework described above are shown in U.S. Pat. No. 5,194,001 to Salvo
 and in U.S. Pat. No. 5,000,687 to Yarovesky, et al.
 A poor fit between the traditional bridgework and the abutment teeth cannot
 be discovered until the finished bridgework is inserted into the patient's
 mouth; a poor fit sometimes develops after a period of wear. To cure a
 poor fit, the bridgework must be removed from the patient's mouth,
 modified, then reattached. Sometimes, several iterations of attachment,
 removal, modification, reattachment are necessary, each requiring an
 office visit by the patient. Attachment wings or crowns run the range of
 mechanical and/or adhesive devices, such as screws, foils, films, screens,
 mastics, hooks, etc. Frequently, the reduction and/or process of
 attachment (especially the use of screws) injures the abutment teeth and
 can lead to caries, abscesses, and/or tooth death. Removal of the
 bridgework after cementation of the attachment wings to the abutment teeth
 sometimes injures the abutment teeth, or even requires their removal.
 For decades there has been a quest for a more efficient, effective, and
 non-invasive means of replacing missing teeth in a fixed manner.
 Extraordinary efforts have been devoted to trying to devise methods that
 do not require cutting or otherwise mutilating the abutment teeth. Two of
 the most common methods devised to avoid reducing the abutment teeth are
 well known as the "Maryland bridge" and the "Rochette bridge." The
 Maryland bridge and the Rochette bridge are constructed with a metal
 framework of nickel-chromium and beryllium in a laboratory, etched with an
 acid medium or sandblasted on the tissue side surface of the attachment
 hooks, and then cemented to the natural abutment teeth with a polymer
 luting agent. Due to the inflexibility of the metal frame and the weak
 bond of the polymer to metal and polymer to teeth, the attachment hooks
 can separate from the abutment teeth. There are additional serious
 disadvantages with the Maryland and Rochette bridges, as well as with
 other indirect bridgework. In the area of aesthetics, the underlying metal
 may "shine-through" the pontic surface, disrupting the color, hue, value
 and shade of the replacement tooth. The high-fusing-porcelain can rapidly
 abrade natural teeth opposite the bridge. The metallic content of the
 metal bridges sometimes precipitates allergic or even less understood
 impairment of the patient's health. There is a growing and real concern
 for the quality and quantity of metal used in dentistry and the
 deleterious effects on the bio-environment of the oral cavity. All three
 kinds of metals utilized in the previously mentioned bridges are bio-toxic
 to some degree. Nickel is known for its allergenic capacity and is an
 experimental carcinogen and equivocal tumor former. Chromium is a
 suspected carcinogen and an equivocal tumor producer. Beryllium is an
 equivocal neoplastic producer concerned with pulmonary problems that
 produce tumors and is an experimental carcinogen.
 In additional to undesirable health side effects, laboratory fabricated
 porcelain/metal bridges have structural and aesthetic deficiencies.
 Structurally, the metal can fracture, the porcelain can fracture, and/or
 the porcelain/metal fused interface can separate. All of these structural
 failures require removal of the bridge for repair. Aesthetically, after
 cementation of the bridge, changes over time in pontic color or shade
 versus natural teeth, or bridgework fit, require removal of the bridge.
 All these deficiencies of indirect, laboratory fabricated porcelain/metal
 bridges are difficult, if not impossible, to resolve. The chronic failure
 of the metal-polymer-tooth bond, and the other deficiencies noted above,
 have prompted research into other bridgework materials, namely those in
 the porcelain, ceramic, and composite groups.
 These other attempts to eliminate or reduce the deficiencies noted above
 all rely, however, on the "indirect method," that is, fabrication of
 bridgework in a dental laboratory or operatory. To improve the strength of
 the bridgework to abutment tooth bond, methyl-acrylate polymers doped with
 more durable filler particles, collectively known as "composites," were
 introduced. Attempts have also been made to affix a natural tooth or a
 fabricated pontic to abutment teeth utilizing webs of materials such as
 metal rods, carbon fiber rods, screens, films, and foils made of various
 materials.
 U.S. Pat. No. 5,171,147, to Burgess, discloses a dental bridge prepared
 using the indirect method in which the bridgework pontic and attachment
 wings are fabricated as an integral unit out of heat-polymerized
 composite. Unlike traditional bridgework, the Burgess bridge does not use
 a metal framework, metal pontics, or fused porcelain, but like traditional
 bridgework, it uses the indirect method, including a pressurized oven. For
 installation in a patient's dental arch, the Burgess bridge requires
 reduction of the abutment teeth, reduction of the attachment wings to
 conform them with the attachment surfaces on the abutment teeth, and the
 use of cements or other bonding agent to fix the Burgess bridge in place.
 Structurally, the Burgess bridge "product" comprises not only a single,
 composite pontic with composite attachment wings, but the cement or other
 bonding agent necessary to give the bridge utility in situ.
 Installing a fixed bridge without cement is contrary to the teaching of the
 prior art, even that of Burgess. Burgess does not disclose or claim a
 bridge that is bonded without a cement, or a bridge of more than one
 pontic, and the shown structure of the Burgess bridge has attachment
 contours that are useless without reduction of the abutment teeth and/or
 attachment wings and cementation. The Burgess bridge "product" is a
 two-element combination: pontic plus cement. Every claim in the Burgess
 patent recites, directly or indirectly, the limitation of cementing the
 bridge to the abutment teeth. An inventive step would be a composite
 bridge of one or more pontics that does not use cement or a luting agent,
 but is an integral bridge in situ, not a combination of "pontic plus
 cement." Moreover, the Burgess bridge has an implied limitation in the
 same way that a threaded bolt has an implied limitation. A threaded bolt
 requires a threaded nut or other threaded channel for utility. The Burgess
 bridge requires reduction of the abutment teeth for utility. All
 embodiments of the Burgess bridge are disclosed as requiring a reduction
 of the abutment teeth in the same way that a threaded bolt requires a
 threaded channel for utility. Fixed bridgework that in all, or virtually
 all, cases does not require reducing the abutment teeth is contrary to the
 teaching of the prior art.
 Burgess describes and claims an "indirect" product that uses a bonding or
 luting agent different, or differently polymerized, from the pontic
 compound, which introduces two chemical interfaces, composite to cement,
 and cement to tooth. An inventive step would be bridge created in situ
 that does not use a different bonding or luting agent and has only one
 chemical interface, composite to tooth. A single compound, single chemical
 interface, completed product is a structurally different product from a
 two compound, two chemical interface, completed product. The Burgess
 bridge lacks utility without cement.
 To use a different structural analysis, the Burgess bridge is made in a
 generic form that requires further adaptation for end use; it is a
 "workpiece" or "blank" lacking conforming attachment surfaces. The
 structure and form of the Burgess bridge permit it to be mass produced. In
 its end-product form, the Burgess bridge fits nobody without structural
 modifications to the cured composite and to the abutment teeth.
 The indirect method has proven to be lengthy and complicated. Approximately
 ten laboratory steps are needed in the simplest traditional bridge
 construction, and with these steps come costs. Some methods are even more
 complex; for instance, U.S. Pat. No. 5,000,687 to Yarovesky et al.
 discloses an indirect method involving about 14 or 15 separate process
 steps. Furthermore, many indirect methods require the abutment teeth to be
 surgically reduced in some form; for example, the process disclosed in the
 patent to Yarovesky et alii requires cutting and contouring of the lingual
 surfaces of the abutment teeth prior to bridge installation. U.S. Pat. No.
 5,120,224 to Golub, seeking to eliminate or minimize the need for abutment
 tooth reduction, discloses a bridge structure wherein a thin fabric
 laminate may be internally sandwiched within the pontic/bridge. The fabric
 extends outwardly from the pontic/bridge for placement on abutment teeth
 and for bonding thereto by an cement or luting agent. As stated in the
 Golub patent, however, the disclosed structure is intended to function
 only as a temporary or provisional bridge. Moreover, it has been found
 that the placement of an inappropriate fabric or screen within composite
 material, particularly within the attachment wings, may weaken, rather
 than strengthen, the bridge framework. All laboratory-based indirect
 methods are therefore relatively costly, time consuming, and ineffective.
 U.S. Pat. No. 4,172,323 to Orlowski discloses a method for securing a
 previously-made pontic or a fixed bridge, wherein a thin film or screen is
 applied to the appropriate surfaces on the abutment teeth. Cement or a
 luting agent is applied to the screens and to the attachment wings of the
 pontic/bridge being installed, whereafter the pontic/bridge is held in
 place while the cement or luting agent cures. Orlowski, however, discloses
 that small undercuts are made in the enamel of the abutment teeth contact
 areas, so as to increase the area available for bonding and resistance to
 shear forces. Despite that attempt to increase contact areas, it has been
 found that these areas are still limited such that weakness of joints
 results. Consequently, the securement structure disclosed by Orlowski has
 been found to be temporary or at best provisional, i.e., lasting
 considerably less than five years.
 Where tooth or dental implant extraction is required before insertion of
 fixed dental bridgework, regardless of whether the bridgework has been
 constructed directly or indirectly, the traditional approach requires two
 to four months healing of the extraction site (alveolar socket) prior to
 bridge installation. The fabrication and installation of a fixed dental
 bridge during the same office visit as extraction of teeth or implants
 from the area to be bridged has heretofore been regarded as impossible.
 Accordingly, there is a need in the art for a method of directly producing
 a permanent dental bridge that (i) eliminates invasive tooth preparation
 steps, (ii) can be done during the same office visit as tooth or dental
 implant extraction, (iii) can bridge an edentulous area of one or more
 alveoli, and (iv) eliminates the need for separate cementation of the
 bridge to the abutment teeth.
 BRIEF SUMMARY OF THE INVENTION
 It is thus an object of the present invention to provide a method of
 constructing a dental bridge which overcomes the drawbacks associated with
 prior art methods.
 It is a further object of the present invention to provide a direct method
 of constructing a permanent dental bridge which is efficient, effective,
 and less inexpensive than traditional bridgework.
 It is a further and more particular object of the present invention to
 provide a direct method of constructing a permanent dental bridge that
 contains one or more pontics and can be accomplished in situ, that is,
 entirely within the patient's mouth, or alternatively ex situ, at least
 partially constructed outside the patient's mouth.
 It is a further object of the present invention to provide reinforcement of
 composite bridgework, especially for multi-pontic composite bridges.
 These and other objects are accomplished by a method of constructing a
 dental bridge in situ, the dental bridge when completed occupying an
 edentulous space between a first abutment tooth and a second abutment
 tooth in a patient's mouth, comprising the steps of applying gingival
 laminations of a composite material, called "base composite," between the
 first and second abutment teeth, forming first and second attachment
 portions from the composite material, the attachment portions respectively
 attaching to corresponding surfaces on the first and second abutment teeth
 without the use of cement or other bonding agent, curing the composite
 material, and optionally introducing one or more reinforcement materials
 in laminations between the abutment teeth for reinforcement, whereby the
 dental bridge is constructed entirely within the mouth of the patient in a
 single office visit. After curing the laminations of base composite,
 additional composite material is applied between the abutment teeth, from
 which the first and second attachment portions and, in the in situ
 process, the body of one or more pontics, continue to be formed, and the
 additional composite material is cured. These latter steps are
 successively repeated, thus forming built-up laminations of composite
 material and optionally of reinforcement material, until the dental
 bridge, including at least one pontic portion, is formed and
 simultaneously secured to the abutment teeth.
 The foregoing objects are also accomplished by a method of constructing a
 dental bridge ex situ, the dental bridge when completed occupying an
 edentulous space between a first abutment tooth and a second abutment
 tooth in a mouth of a patient, comprising the steps of fabricating a
 composite pontic ex situ, applying base composite material between
 attachment surfaces on the abutment teeth, curing the composite material,
 applying one or more laminations of additional composite material between
 the abutment teeth, optionally introducing one or more reinforcement
 materials in laminations between the abutment teeth for reinforcement,
 inserting the previously prepared composite pontic into the laminations of
 base composite and any reinforcement composite, and curing the
 laminations.
 In the in situ process and the ex situ process, the optional reinforcing
 material is selected from the group comprising bondable reinforcement
 ribbon, metallic or non-metallic rods, metallic or non-metallic posts
 (including posts made of bondable reinforcement ribbon), composite
 material that differs from the base composite, foils, films, trusses
 (including tensegrity masts), and screens.
 A composite with a modulus of elasticity comparatively lower than that of
 the base or of the reinforcement composite, can be used in the incisal,
 buccal, labial, and occlusal portions of a pontic, and introduces
 resilience and dispersion of biting and/or chewing over the base composite
 and any reinforcement material.
 In either the in situ process or the ex situ process, a gingival stent can
 be utilized to act as a platform upon which the successive laminations of
 one or more types of composite may be formed and also, if employed
 immediately following tooth or implant extraction, to act as a bandage or
 obturator. The stent is inserted into the patient's mouth before
 application of composite material between the abutment teeth, and is
 removed after formation of the completed bridge but prior to the
 contouring and finishing thereof. The gingival stent comprises a base and
 a leaf extending from the base. The base of the stent has a lateral margin
 into which concave sections are formed that fit snugly around lingual
 surfaces of the abutment teeth and teeth adjacent thereto. When the stent
 is placed within the mouth, the leaf of the stent covers the gingival
 surface of the edentulous space to be bridged.
 The fully composite bridge may contain a plurality of pontics. The greater
 the number of pontics included in the bridge, the more desirable it may be
 to introduce reinforcement material.
 In summary, the foregoing objects are achieved by applying base composite
 between the first and second abutment teeth, forming first and second
 attachment portions from the base composite, the attachment portions
 respectively attaching to corresponding surfaces on the first and second
 abutment teeth, and curing the composite material to produce fixed dental
 bridgework. The foregoing objects are also achieved by fabricating a
 composite pontic ex situ, applying composite material between the first
 and second abutment teeth, curing the composite material, applying one or
 more laminations of additional composite material between the first and
 second abutment teeth, inserting one or more fabricated composite pontics
 into the one or more laminations, and curing the one or more laminations
 to produce fixed dental bridgework. For added strength, reinforcement
 material can be introduced during construction of the laminated, composite
 bridge. For better dispersion of biting and chewing forces, a more
 resilient composite can be used to form the incisal and occlusal portions
 of a pontic.

DETAILED DESCRIPTION OF THE INVENTION
 The "immediate, laminated, light-cured direct multi-composite bridge"
 comprises one or more "direct composite pontics," a bridge substructure,
 attachment portions, and optional reinforcement portions that are
 integrally fabricated and affixed in place between two or more abutment
 teeth in an immediate process; moreover, abutment teeth need not be
 reduced. "Composite" means light curable composite dental materials, such
 as various formulations of a colloid paste of methyl methacrylate resin
 and silica commonly available from dental supply houses, preferably of the
 type made commercially available from Prisma APH of Milford, Del.
 "Composite pontic" means a false tooth ("pontic") made only of light-cured
 composite. "Direct multi-composite pontic" means a composite pontic made
 without dental laboratory assistance by application and light curing of
 successive laminations of two or more types of composite, either in situ
 or ex situ, as explained below. "Direct composite bridge" means a bridge
 according to the present invention made using one or more types of
 composite. "Immediate" means that the process of fabricating and affixing
 the composite bridge can be completed in one office visit. The fabrication
 of an individual composite pontic can be performed either completely
 within the patient's mouth (called "in situ" or intraoral fabrication) or
 outside the patient's mouth (called "ex situ" or operatory fabrication). A
 "direct composite bridge" contrasts with traditional "indirect" methods of
 dental bridge construction that require fabrication of bridgework in a
 dental laboratory and also with methods that require the use of cement or
 a luting agent to affix bridgework to the abutment teeth.
 Different formulations of composite have different physical
 characteristics; formulations that cure with higher shear and tensile
 strength tend to have less resilience or elasticity; formulations that
 cure with lower shear and tensile strength tend to have higher resilience
 or elasticity. A direct composite bridge may contain reinforcing material,
 as described below, yet also use a more resilient composite for incisal
 and occlusal portions of a pontic. "Base composite" means light curable
 composite dental materials with a modulus of elasticity acceptable for use
 throughout all portions of a direct composite bridge. "Reinforcement
 composite" means light curable composite dental materials with a modulus
 of elasticity comparatively higher than that of the base composite.
 "Finishing composite" means light curable composite dental materials with
 a modulus of elasticity comparatively lower than that of the base
 composite or of the reinforcement composite.
 The in situ fabrication of an immediate laminated, light-cured composite
 bridge will be described in detail first, followed by detailed
 descriptions of the use of a gingival stent, reinforcement methods, and ex
 situ fabrication of such a bridge.
 FIG. 1 shows a palatal view of an upper dental arch 10 of a patient's
 mouth. Dental arch 10 includes a row of teeth, one of which teeth has been
 removed, thereby leaving an edentulous (toothless) space 12 between
 abutment teeth, namely, a first abutment tooth 14 and a second abutment
 tooth 16. In the first step of the in situ method of direct composite
 bridge fabrication according to the present invention, each attachment
 surface of each abutment tooth 14, 16 is etched, preferably with a 35%
 phosphoric acid gel for about twenty seconds. As used herein, the term
 "attachment surface" means the surface areas of the abutment teeth 14, 16
 to which dental composite will be applied during construction of a direct
 composite bridge, which attachment surfaces normally include proximal
 surfaces 14a, 16a (FIG. 1) and lingual surfaces 14b, 16b (FIG. 1), and may
 include facial surfaces 14c, 16c (FIG. 1) of abutment teeth 14 & 16.
 FIG. 2 shows a palatal view of upper dental arch 10 after base composite 28
 has been applied between the attachment surfaces of the abutment teeth 14,
 16. Preferably, the base composite 28 is applied in a series of strings or
 laminations leading from the attachment surface of the first abutment
 tooth 14 across the edentulous space 12 to the attachment surface of the
 second abutment tooth 16, each string being no thicker than 1-2 mm to
 ensure proper photo-curing. The initial laminations of base composite are
 applied close to the alveolar ridge in edentulous space 12 of dental arch
 10. Subsequent laminations build up the bulk of the applied base composite
 to create a pontic or pontic substructure, as explained below, in the
 region of the edentulous area 12 and to create the attachment portions
 28a, 28b.
 FIG. 3 shows a frontal view of dental arch 10 after base composite material
 28 has been applied between the attachment surfaces of the abutment teeth
 14, 16. Referring to FIGS. 2 and 3, the initial laminations of base
 composite 28 are smoothed with various instruments and shaped so as to
 begin to form a first attachment portion 28a on the attachment surface of
 first abutment tooth 14, and a second attachment portion 28b on the
 attachment surface of the second abutment tooth 16. It has been found that
 the attachment surface on each abutment tooth can exceed 1 cm.sup.2, thus
 providing an exceptionally strong bridge attachment. The initial, shaped
 laminations of base composite 28 closest to the gingiva are then cured,
 preferably with a light source (not shown). Following that curing step,
 additional base composite is applied between the abutment teeth 14, 16,
 and the first and second attachment portions 28a, 28b. These steps of
 applying additional composite material, shaping the uncured composite
 material to form first and second attachment portions and a pontic in situ
 (or pontic substructure in the case of the ex situ process) between the
 abutment teeth, and curing the additional composite material are
 successively repeated. Each lamination should be no thicker than 1-2 mm to
 ensure proper photo-curing.
 To ensure a broad, perfectly conforming bond by the composite material with
 the etched enamel in the attachment surfaces, it is important to apply
 continuous strings of composite material across the attachment surface,
 rather than merely "tacking" the end of a lamination to a single point on
 the attachment surface, or building and curing an attachment portion and
 then building and curing an adjacent pontic or pontic substructure.
 Preferably, the inner portion of a pontic and the external faces of an in
 situ pontic are concurrently built and cured as integral layers, beginning
 with the layer adjacent to the gingiva and ending with the crown of the
 pontic, rather than building and curing the substructure, then applying,
 shaping, and curing a veneer of composite for the external faces of the
 bridge. The attachment portion may include the buccal or labial portions
 of an abutment tooth, especially if such abutment tooth is lingually
 disposed. The series of shaped and cured laminations form the attachment
 portions and the pontic. A completed in situ, composite bridge made of a
 single composite material, is shown in FIG. 3.
 FIG. 4 shows a frontal view of a composite bridge spanning a single
 alveolus edentulous area and provides datum lines a-a' and b-b' for the
 cross-section views in FIG. 4A and FIG. 4B, respectively. To strengthen a
 composite bridge, reinforcement materials can be introduced in the core
 area 100 (FIG. 4A) of the bridge during construction of the bridge. To
 construct a reinforced composite bridge, after applying, shaping, and
 curing laminations of base composite in the layer adjacent to the gingiva,
 reinforcing material selected from the group consisting of reinforcement
 composite, bondable reinforcement ribbon, metallic or non-metallic rods,
 foils, films, trusses, masts, and screens is inserted or applied in or
 near core area 100 of the bridge. Reinforcement composite can be applied
 so that it does, or does not, form part of the attachment portions 28a,
 28b. FIG. 4B shows a cross-section of a reinforced composite bridge in
 which only base composite comprises the attachment portion. Various types
 of reinforced composite bridges are described in detail, and common
 sources of reinforcement materials are identified, after the following
 sections about the use of a gingival stent and of construction of
 multi-pontic composite bridges.
 If the missing tooth or dental implant has been extracted immediately prior
 to the time of bridge fabrication and installation, then it has been found
 that the use of a gingival stent is particularly advantageous. Referring
 to FIGS. 5, 6, and 7, to control, form, and contour the flow of uncured
 composite laminations over the edentulous space 12 (FIGS. 1 & 2) prior to
 solidification by light curing, a gingival stent 20 is used. The gingival
 stent 20 is installed commencing approximately five minutes after tooth or
 dental implant extraction is completed. The gingival stent 20 has a dual
 function: it acts as a bandage or obturator stabilizing the clotting
 process in the alveolar socket (if tooth extraction occurs during the same
 office visit as bridge formation), and it also serves as a platform upon
 which the composite bridge is fabricated.
 Referring to FIGS. 5, 6, & 7, the gingival stent 20 includes a base 22
 having a lateral margin 25 (FIGS. 6 and 7) into which a plurality of
 concave sections 24 are formed. Concave sections 24 are dimensioned to
 snugly fit around lingual surfaces of the abutment teeth 14, 16 and teeth
 adjacent thereto (such as teeth 15, 17, 19 in FIG. 1). A leaf 26 (FIGS. 6
 & 7) extends from the facial margin 25 of the base 22; the leaf's shape
 conforms to the gingival surface in the edentulous space 12 (FIG. 1) when
 the gingival stent 20 is placed within the patient's mouth. Preferably,
 leaf 26 is formed integrally with the base 22 such that the leaf 26 and
 the base 22 form a one-piece structure.
 The gingival stent 20 is preferably constructed with vinyl polysiloxane
 impression material or equivalent, such as that commercially available as
 type "o" putty from GC America, Inc. of Chicago, Ill. under the trademark
 EXAFLEX. The material is mixed in hand and adapted to the lingual surfaces
 of the abutment teeth and adjacent teeth, molded intraorally and
 interdentally where possible, to cover the entire edentulous ridge to the
 facial cervical, defined as the substantially straight datum line a-a' in
 FIG. 9, passing through or very near the cervical surface (the area where
 the gum meets the tooth) of each of the abutment teeth 14, 16. The lateral
 face 25 of gingival stent 20 should be even, in a horizontal attitude,
 with the tooth cervical areas. The setting agent in the polysiloxane
 material causes the gingival stent 20 to solidify as formed. When set, the
 gingival stent 20 is removed and contoured with a fine fluted finishing
 bur to minimal acceptable thickness. During the months that follow the
 extraction, the alveolar ridge in the edentulous area 12 gradually shrinks
 as it heals; this shrinkage exposes a space gingival to the tissue side of
 the composite bridge. That space is easily closed by applying additional
 composite in the gingival space and light curing the composite to the
 existent bridge. Some space should be left for hygienic irrigation,
 however.
 Referring to FIGS. 8 & 9, the gingival stent 20 is inserted into the
 patient's mouth before application of any composite material. FIGS. 8 & 9
 show a direct composite bridge constructed using a single composite
 material, and additionally shows the leaf 26 of the gingival stent 20
 covering the previously-exposed alveolar ridge in the edentulous area 12;
 the lateral faces of leaf 26 are contiguous with both abutment teeth 14,
 16. The leaf 26 of the stent 20 acts as a platform for the placement of
 the base composite 28, meaning that the composite material occupying the
 edentulous space 12 contacts the stent face on the opposite side of leaf
 26 from the gingiva during the bridge fabrication process.
 To construct a reinforced composite bridge using a gingival stent, a
 gingival stent is formed and inserted intraorally in the same manner as
 for a stent-assisted bridge constructed of a single composite material.
 FIG. 10 shows a frontal view of a composite bridge spanning a single
 alveolus edentulous area, and provides datum lines a-a' and b-b' for the
 cross-section views in FIG. 11 and FIG. 12, respectively. The gingival
 stent is used as a platform for the initial laminations of base composite,
 and reinforcement materials are introduced in or near core area 100 (FIG.
 11) of the bridge during construction of the bridge. Other than the
 insertion and removal of the stent, the process of constructing a
 reinforced composite bridge is the same as described above for
 constructing a reinforced composite bridge without using a gingival stent.
 FIG. 12 is a cross-section view, along the datum line a-a' shown in FIG.
 10, of a direct, composite bridge constructed using base composite,
 reinforcement composite 105 in core area 100, and a gingival stent. The
 gingival stent is removed no later than the completion of the direct
 composite bridge.
 As explained above, if a stent is not used, the laminations of base
 composite in the edentulous area 12 (FIG. 1) are placed atop the alveolar
 ridge. Use of a gingival stent may not be necessary if a patient's
 alveolar ridge has healed following tooth or implant extraction prior to a
 given office visit, which would be the case if a direct composite bridge
 were replacing traditional cemented bridgework. When constructing direct
 composite bridgework over a healed alveolar ridge in a patient's maxillary
 arch, gravity tends to create a gap between gingiva and composite), and
 when constructing direct composite bridgework over a healed alveolar ridge
 in a patient's maxillary or mandibular arch, residual saliva on the
 alveolar ridge tends to create a gap between gingiva and composite; the
 gingival gap thereby created, upon completion of the direct composite
 bridge, is acceptable for hygienic irrigation of the alveolar ridge
 proximal to the bridge. During application of the reinforcement composite
 in the core area 100 (FIG. 4A), laminations of reinforcement composite are
 applied that either do not terminate on the attachment surfaces, as shown
 in FIG. 13, or terminate on the attachment surfaces, as shown in FIG. 14.
 FIG. 13 shows a cross-section view, along the datum line a-a' shown in
 FIG. 2, of a direct, composite bridge constructed using base composite
 that does contact abutment teeth and reinforcement composite that does not
 contact the abutment teeth. Reinforcement composite has a higher modulus
 of elasticity than base composite, and tends to flex less than base
 composite and to disperse incisal and occusal forces across the area in
 which reinforcement composite is applied. Whether the less flexible
 reinforcement composite should be part of the attachment portion, and
 thereby convey incisal or occlusal forces more directly to the abutment
 teeth 14, 16, is in part determined by how strong, and how strongly
 affixed in the mandible or maxilla, the abutment teeth are. FIG. 14 is a
 cross-section view, along the datum line a-a' shown in FIG. 2, showing a
 direct, composite bridge constructed using base composite and
 reinforcement composite that both contact the abutment teeth. The
 remaining steps in completing the direct composite bridge are as described
 above.
 An endodontic post can be used to reinforce a direct composite bridge.
 Unlike other reinforcement materials, which are embedded in, near, or as,
 the core laminations of the pontic, endodontic posts protrude through the
 alveolar ridge 18 (FIG. 15), through the initial laminations of base
 composite, and into the core area of the pontic. FIG. 15 is a
 cross-section view, along the datum line a-a' shown in FIG. 4, showing a
 direct, composite bridge constructed using an endodontic post 110 anchored
 in the alveolar ridge 18, with the protruding portion 110a of the
 endodontic post embedded in base composite 28 and reinforcement composite
 105. If crowns on posts are to be replaced by a direct composite bridge,
 the crowns are reduced to reveal the posts. The exposed posts can be
 shaped to provide reinforcement for a direct composite bridge or reduced
 to be flush with the top of the alveolar ridge. Posts protruding above the
 alveolar ridge normally preclude, or complicate, the use of a gingival
 stent. The protruding portion 110a of an endodontic post 100 is etched,
 preferably with a 35% phosphoric acid gel for about twenty seconds, at the
 same time the attachment surfaces are etched. The initial and subsequent
 laminations of composite are applied to encase the protruding portion 110a
 of the endodontic post 110. The remaining steps in completing the direct
 composite bridge are as described above. Reinforcement of a direct
 composite bridge using an endodontic post is normally not used unless the
 alveolar ridge around the post has healed, thereby minimizing the need for
 use of a gingival stent and possible problems related to seating of the
 post in the mandibular or maxillary arch. Care should be taken so that the
 protruding portion 110a of the endodontic post 110 does not terminate too
 close to the buccal or labial surface of the pontic and thereby discolor
 the pontic.
 A direct composite bridge can span an edentulous area of more than one
 alveolus. FIG. 16 is a front view of a dental arch of a mouth of a
 patient, showing an edentulous space of two alveoli between first and
 second abutment teeth. FIG. 17 shows a direct, composite bridge
 constructed in a two-alveoli edentulous space 112 (FIG. 16) between first
 and second abutment teeth 14, 16. The steps in constructing a direct
 composite bridge that spans an edentulous area of more than one alveolus
 are as described above for a direct composite bridge that spans an
 edentulous area of one alveolus, except for the greater distance between
 abutment teeth 14, 16 across which the composite and any reinforcement
 materials must be applied. FIG. 17A is a cross-section view, along the
 datum line a-a' shown in FIG. 17, showing a direct, two-pontic composite
 bridge constructed using a single composite 28. The cross-section view in
 FIG. 17 along datum line c-c' is substantially identical to that along
 datum line a-a'. FIG. 17B is a cross-section view of the attachment
 portion along the datum line b-b' shown in FIG. 17, showing a direct,
 two-pontic composite bridge constructed using a single composite 28 in the
 attachment portion 28a.
 Reinforcement composite can be applied entirely within the substructure of
 the pontics in a multi-pontic direct composite bridge, so that the
 reinforcement composite does not contact the abutment teeth 14, 16. FIG.
 19 shows a cross-section view, along the datum line a-a' shown in FIG. 18,
 of a direct, two-pontic composite bridge constructed using base composite
 that does contact abutment teeth and reinforcement composite that does not
 contact the abutment teeth. FIG. 19A is a cross-section view, along the
 datum line a-a' shown in FIG. 18, showing a direct, two-pontic composite
 bridge constructed using base composite and reinforcement composite that
 both contact the abutment teeth 14, 16. The factors that determine whether
 the reinforcement composite should attach directly to the abutment teeth
 are the same in multi-pontic composite bridges as in single pontic
 reinforced composite bridges, as described above. During application of
 the reinforcement composite in the core area 100 (FIG. 20), laminations of
 reinforcement composite are applied that either terminate on the
 attachment surfaces, as shown in FIG. 19A, or do not terminate on the
 attachment surfaces, as shown in FIG. 19. The remaining steps in
 completing the direct composite bridge are as described above. FIG. 21 is
 a cross-section view of the attachment portion along the datum line b-b'
 shown in FIG. 17, showing a direct, two-pontic composite bridge
 constructed using base composite 28, and reinforcement composite 105 in
 the core of the pontic.
 An endodontic post can be used to reinforce a multi-pontic, direct
 composite bridge. The steps in constructing an endodontic post-reinforced,
 multi-pontic, direct composite bridge are as described above for an
 endodontic post-reinforced, direct composite bridge that spans an
 edentulous area of one alveolus, except for the greater distance between
 abutment teeth 14, 16 across which the composite and any longitudinal
 reinforcement materials must be applied, and the use of more than one
 endodontic post. FIG. 22 is a cross-section view, along the datum line
 a-a' of the two-pontic bridge shown in FIG. 17, showing a direct composite
 bridge constructed using base composite 28, reinforcement composite 105,
 and an endodontic post 110. The cross-section view, along the datum line
 c-c' shown in FIG. 17, is the same as that shown in FIG. 22.
 In addition to the use of reinforcement composite and of endodontic posts
 for reinforcement, other materials can be used, e.g., bondable
 reinforcement ribbon, metallic or non-metallic rods, foils, films,
 trusses, masts, or screens. These reinforcement materials can be used in
 either single pontic, or multi-pontic, composite bridges. When bondable
 reinforcement ribbon, metallic or non-metallic rods, foils, films,
 trusses, or screens are used, after lamination and curing of the initial
 one or more layers of base composite, the selected reinforcement material
 is held in place in or near the core area 100 (FIG. 20) by laminations of
 composite material (either base composite or reinforcement composite),
 then additional laminations of base composite are applied between the
 attachment surfaces 28a, 28b (FIG. 18) and shaped to form the external
 faces of the attachment portions and pontic, and then all composite in the
 layer just applied is cured, securing the reinforcement material in place.
 It is important to avoid introducing air pockets or contaminants when
 laminating the reinforcement material in place. Additional laminations of
 composite are applied in and near core area 100 and other portions of the
 bridge (either base composite or reinforcement composite, according to the
 type and placement used in the just-cured laminations), shaped, and cured.
 The bridge is thereafter completed in the manner described for a composite
 bridge reinforced only with reinforcement composite in core area 100.
 FIG. 23 is a cross-section view, along the datum line a-a' of the
 multi-pontic bridge shown in FIG. 17, showing a direct, composite bridge
 constructed using base composite 28, reinforcement composite 105, and rod
 reinforcement 115. The rod reinforcement 115 is shown embedded both in
 base composite 28 and in reinforcement composite 105, but could have been
 embedded in only one type of composite. Rod reinforcement is available
 from Moyco Union Broach Division, 589 Davies Drive, York, Pa. 17402.
 FIG. 24 is a cross-section view, along the datum line a-a' of the
 multi-pontic bridge shown in FIG. 17, showing a direct, composite bridge
 constructed using base composite 28, reinforcement composite 105, and
 bondable ribbon reinforcement 120. The bondable ribbon reinforcement 120
 is shown embedded both in base composite 28 and in reinforcement composite
 105, but could have been embedded in only one type of composite. Bondable
 ribbon reinforcement is specially made to form strong bonds with dental
 composite materials. Bondable ribbon reinforcement is available from
 Ribbond, Inc., 1402 Third Ave., Ste 1030, Seattle, Wash. 98101.
 FIG. 25 is a cross-section view, along the datum line a-a' of the
 multi-pontic bridge shown in FIG. 17, showing a direct, composite bridge
 constructed using base composite 28, reinforcement composite 105, and foil
 or film reinforcement 125. The foil or film reinforcement 125 is shown
 embedded only in base composite 28, although it could also have been
 embedded in reinforcement composite 105. Foil and film reinforcement is
 available from Glasspan, Inc., 101 John Robert Thomas Drive, Extion Pa.
 19341.
 FIG. 26 is a cross-section view, along the datum line a-a' of the
 multi-pontic bridge shown in FIG. 17, showing a direct, composite bridge
 constructed using base composite 28, reinforcement composite 105, and
 screen reinforcement 130. The screen reinforcement 130 is shown embedded
 only in base composite 28, although it could also have been embedded in
 reinforcement composite 105. Screen reinforcement is available from
 Jordco, Inc., 595 N.W. 167th Avenue, Beaverton, Oreg. 97006.
 FIG. 27 is a cross-section view, along the datum line a-a' of the
 multi-pontic bridge shown in FIG. 17, showing a direct, composite bridge
 constructed using base composite, reinforcement composite, and truss
 reinforcement. The truss reinforcement 135 is shown embedded only in base
 composite 28, although it could also have been embedded in reinforcement
 composite 105. Truss reinforcement is available from Gramm Technology,
 Inc., 3016 PS Business Center, Woodbridge, Va. 22192.
 FIG. 28 is a cross-section view, along the datum line a-a' of the
 multi-pontic bridge shown in FIG. 17, showing a direct, composite bridge
 constructed using base composite, reinforcement composite, and tensegrity
 mast reinforcement. The tensegrity mast reinforcement 140 is shown
 embedded only in base composite 28, although it could also have been
 embedded in reinforcement composite 105. Tensegrity mast reinforcement is
 custom made according to the description of tensegrity technology in
 "Cosmography," by R. Buckminster Fuller, Macmillian Publishing Co.
 A composite with a comparatively lower modulus of elasticity than the
 reinforcement composite, when used in the incisal and occlusal portions of
 a pontic, introduces resilience and dispersion of biting and/or chewing
 over the base composite and over any reinforcement material. A composite
 that responds better to polishing, or is more stain resistant, than base
 composite may be selected for the incisal, occlusal, labial, and/or buccal
 portions of composite pontics. The composite used for the incisal,
 occlusal, labial, or buccal portions of a pontic, if different from the
 base composite and reinforcement composite, is called "finishing
 composite". Finishing composite can be used in single-pontic composite
 bridges or in multi-pontic composite bridges. FIG. 29 is a front view of a
 direct, two-pontic composite bridge constructed of primarily of base
 composite 28, but with finishing composite 145 in the incisal and some
 facial portions of the pontics. The steps in constructing a direct
 composite bridge that includes finishing composite are as described above
 for any of the other reinforced or unreinforced, direct composite bridges,
 except that the final laminations of composite in the incisal, occlusal,
 labial, and/or buccal portions of the pontics are made using finishing
 composite. After shaping and curing of the finishing composite, the bridge
 is contoured and finished. FIG. 30 is a cross-section view, along the
 datum line a-a' shown in FIG. 29, showing a direct, two-pontic composite
 bridge constructed using base composite 28 for all but the laminations in
 the incisal and some facial portions of the pontic, and finishing
 composite 145 in the incisal and some facial portions of the pontics.
 As alluded to above, finishing composite can also be used in reinforced,
 direct composite bridges, both single pontic and multi-pontic. FIG. 31
 shows a direct, two-pontic composite bridge constructed of base composite,
 reinforcement material, and finishing composite. FIG. 32 is a
 cross-section, along the datum line a-a' shown in FIG. 31, showing a
 direct, two-pontic composite bridge constructed using base composite 28,
 core area 100 (containing base composite or reinforcement material) of the
 pontic, and finishing composite 145. Reinforcement of a direct, composite
 bridge that includes finishing composite is not limited to the use of
 reinforcement composite, and can include any of the reinforcement methods
 described above. FIG. 33 is a cross-section view, along the datum line
 a-a' shown in FIG. 31, showing a direct, two-pontic composite bridge
 constructed using base composite 28, reinforcement composite 105, rod
 reinforcement 115, and finishing composite 145. The steps in constructing
 a reinforced, direct composite bridge that includes finishing composite
 are as described above for any of the other reinforced direct composite
 bridges, except that the final laminations of composite in the incisal,
 occlusal, labial, and/or buccal portions of the pontics are made using
 finishing composite.
 Shaping of composite is done before curing of the fresh laminations of
 composite. Viscosity of most types of light-cured composite is
 proportional to the proximity and length of irradiation by a curing light.
 The iterations of lamination, irradiation, and shaping are a matter of
 composite formulation, pontic or attachment portion being built, and
 individual preference and skill. The final laminations of composite may
 include extra laminations of composite, called "overbulked composite", to
 insure adequate pontic volume, especially when final shaping is to be done
 by reduction of cured composite. It is critical when applying composite to
 avoid the introduction of air bubbles and contaminants.
 The application, shaping, and curing of laminations ceases when a composite
 dental bridge, including the attachment portions and all portions of each
 pontic, has been formed. The bridge resulting from this novel process of
 fabrication is a solid, acceptably flexible, high strength structure that
 integrates pontics, attachment portions, substructure, and optional
 reinforcement. Once a direct, composite bridge has been formed, any
 gingival stent 20 (FIG. 5), including its leaf 26, that was used during
 bridge construction is removed from the patient's mouth and discarded.
 Stent removal is made possible by the fact that the gingival stent 20,
 being constructed of material differing from the composite material
 comprising the bridge, does not chemically fuse or weld to the composite.
 Without such adhesion, the gingival stent 20, once the composite has been
 cured, easily slides from beneath the bridge pontic portion and from
 around the abutment teeth 14, 16 and teeth adjacent thereto.
 As a final step in the in situ process, the bridge is contoured and
 finished, i.e., any "overbulked" composite is trimmed with various rotary
 instruments such as diamond burs, fine fluted finishing burs, and rubber
 wheels, then finished with polishing paste. If an error is made during
 finishing, the area of the error can be cleaned of debris, appropriate
 composite (base or finishing) applied, shaped, and cured, and then
 finished.
 In the ex situ process, which will now be described in detail, a composite
 pontic must first be fabricated outside the patient's mouth, e.g., in an
 operatory.
 In FIGS. 34 & 35, a layer of warm wax is placed over another tooth, such as
 lateral incisor 15, within dental arch 10, thereby forming a wax mold 32
 of lateral incisor 15. The wax used to comprise mold 32 is preferably a
 number 3 wax, commercially available from Miles, Inc. of South Bend,
 Indiana under the trademark MODERN MATERIALS.
 Referring to FIGS. 36, 37, & 38, the mold 32 is removed from the lateral
 incisor 15 (FIG. 1) and is allowed to cool. As seen in FIG. 37, the mold
 32 has a somewhat V-shaped profile, whereby an internal wall 32a of the
 mold 32 defines an internal chamber 34. A layer of un-filled resin polymer
 is placed within mold 32 and is then cured. The layer of unfilled resin
 polymer acts as a lubricant on wall 32a and allows for ease of removal of
 the completed pontic from the mold 32, to be described later herein. Next,
 layers of a filled resin polymer are successively placed within the mold
 32, preferably at a thickness each of 1 mm to 2 mm, and cured until a
 completed composite pontic 36 is formed within the mold 32, as shown in
 FIG. 38.
 As depicted in FIGS. 39, 40, & 41, the mold 32 is peeled back, or removed,
 from the completed pontic 36, which is seen as being substantially
 identical to the lateral incisor 15 from which the mold 32 was formed.
 Although these figures show a single pontic 36, the term "pontic", as used
 in the claims stated herein, shall be construed to mean a plurality of
 pontics (if the patient is initially missing more than one tooth), as well
 as a singular pontic.
 Referring to FIGS. 42, 43, & 44, the pontic fabrication process can employ
 a crown form 35 instead of the mold 32, such that mold formation steps
 would be eliminated, with polymer deposition and curing steps occurring
 identically in the manner described with regard to the wax mold process.
 Custom-fabricating the pontic 36 using the ex situ method described above
 has been found to be advantageous over merely selecting a pontic from
 commercially available stock, because stock pontics will not chemically
 adhere to attachment portions or a bridge substructure, which are formed
 of composite material according to the present invention.
 In FIGS. 46 & 47, the attachment surfaces of the abutment teeth 14, 16 have
 been prepared, and the gingival stent 20, if used (including leaf 26),
 inserted in the same manner as previously described with regard to the in
 situ process. Here, the completed pontic 36 is aligned with the edentulous
 space 12, as shown in FIG. 45. Next, an initial layer of composite
 material 38 is seen as having been applied between the first and second
 abutment teeth 14, 16, respectively. Layer 38 is then cured, whereafter a
 lamination of additional composite material 40 is applied between the
 abutment teeth; curing does not immediately follow; rather, the composite
 pontic 36 is first inserted into the uncured lamination 40, as seen in
 FIG. 46. Once this occurs, lamination 40 is cured. If desired, the
 gingival surface of composite pontic 36 may be serrated, or roughened,
 while partially cured to create more surface area with which to bond the
 pontic to one or more uncured composite laminations on the bridge
 substructure.
 Referring to FIG. 47, successive additional laminations of composite
 material and curing thereof result in a completed dental bridge 42,
 including pontic portion 42a and attachment portions 42b, 42c. If desired,
 reinforcement material can be introduced in the manner described for the
 in situ process. The ex situ process is then completed by shaping and
 finishing the bridge 42 in the same manner as that described with regard
 to the in situ process.
 It is therefore seen that a direct, immediate, light-cured direct composite
 dental bridge spanning one or more alveoli, with or without reinforcement,
 and constructed with one or more dental composites may be efficiently
 constructed in a manner which results in several advantages, namely: a) no
 tooth preparation by extensive enamel reduction, which prevents pulpal
 death and attendant complex endodontic treatment; b) often no need for
 anesthetic injections; c) no need for dental impressions in the in situ
 process; d) no need for temporary bridges; e) aesthetic input from the
 patient at the time of bridge lamination and completion; f) elimination of
 casting or porcelain errors within the laboratory; g) obviates errors in
 occlusion (bite) due to articulation errors and model inaccuracies; h)
 revolutionary "one-phase" material application; i) no laboratory
 procedures saving time, materials, and expense; j) no cementation of the
 bridge framework to the abutment teeth after the indirect construction of
 the bridge framework with the pontic; k) one appointment only for the
 patient; l) when non-metallic reinforcement materials are used, no metal
 corrosive activity or ionization, thus preventing metal ion
 bio-contamination; m) the bridge can be reinforced as appropriate; n)
 finishing errors can be easily corrected; and, o) the bridge will not need
 to be removed for repair or correction of shade, since all addition or
 shade changes may be made directly to the pontics in the existing direct
 composite bridge at any time in the future.
 As the above description is merely exemplary in nature, being merely
 illustrative of the invention, many variations will become apparent to
 those of skill in the art. Such variations, however, are included within
 the spirit and scope of this invention as defined by the following
 appended claims.