Dental composite placement protocol and dental restorations formed thereby

Abstract

A dental composite placement protocol provides a flowable composite as the dentin replacement on the pulpal floor and gingival box and then cures the flowable composite. A first increment layer of paste-type composite resin is placed against the cured flowable composite whereby it fully encapsulates the preparation walls including the circumference of the cavosurface enamel margin, including the interproximal enamel, axial wall dentin, and matrix band. A stress relieving space is positioned in the middle of the preparation walls and the first increment layer, configured for allowing the composite to flow without constraint during curing. The first increment layer is cured. A final increment layer of paste-type composite resin is placed in the remaining space against the light-cured flowable composite and against the light-cured first increment wherein the final increment layer is placed against cured composite an not against tooth substrates; and the final increment layer is cured.

Description

DENTAL COMPOSITE PLACEMENT PROTOCOL AND DENTAL RESTORATIONS FORMED THEREBY RELATED APPLICATIONS

[0001] The present application claims priority to U.S. Patent Application Serial Number 63 / 681,420 filed August 9, 2024, which application is incorporated herein by reference in its entirety. BACKGROUND OF THE INVENTION

[0002] 1. Field of the Invention

[0003] The present invention relates to dental composite placement protocol and dental restorations formed thereby.

[0004] 2. BACKGROUND INFORMATION

[0005] Dental restoration, dental fillings, or simply fillings are treatments used to restore the function, integrity, and morphology of missing tooth structure resulting from caries or external trauma as well as to the replacement of such structure supported by dental implants. Caries, also known as cavities or tooth decay, is generally a breakdown of teeth due to acids produced by bacteria. For general background see “Your Teeth and Cavities” WEBMD 2017.

[0006] Dental restorations follow two broad types of direct restorations and indirect restorations and are further classified by location and size. Direct restoration techniques involve placing a soft or malleable filling into the prepared tooth and building up the tooth. The material is then set hard and the tooth is restored. In indirect restoration techniques the restoration is fabricated outside of the mouth using the dental impressions of the prepared tooth.

[0007] Amalgams have long been used for dental restorations and are alloys formed by a reaction between two or more metals, one of which is mercury. It is a hard restorative material and is silvery-grey in color. One of the oldest direct restorative materials still in use, dental amalgam was widely used in the past with a relatively high degree of success. Recently its popularity has declined due to a number of reasons, including the development of alternative bonded restorative materials, increase in demand for more aesthetic restorations and Atlas Page 1 of 20 Patent Applicationpublic perceptions concerning the potential health risks of the material. See Opdam, N.J. et al., A Retrospective Clinical Study on Longevity of Posterior Composite and Amalgam Restorations. Dent Mater. 2007; 23:2-8, and Moncada, G. et al., Longitudinal Results of a 10-Year Clinical Trial of Repair of Amalgam Restorations. Oper Dent.2015; 40:34-43.

[0008] Dental composites, commonly described as "tooth-colored fillings", are a group of restorative materials now commonly used in dentistry. They can be used in direct restorations to fill cavities, minor buildup for restoring tooth wear (non-carious tooth surface loss) and filling in small gaps between teeth (labial veneer). Dental composites are also used as indirect restoration to make crowns and inlays in the laboratory. Examples of such commonly used monomers include bisphenol A-glycidyl methacrylate (BISMA) and urethane dimethacrylate (UDMA), together with tri-ethylene glycol dimethacrylate (TEGMA). Dental composites are typically cured (polymerized) with a light of a given wavelength. The ability to polymerize light-activated dental composite materials with dental light-curing units (DLCUs) has revolutionized dentistry. See Frazier, K et al., Dental Light-Curing Units, Journal of the American Dental Association, July 2020 Volume 151, issue 7 p544-545.

[0009] Dental composites have become the primary material for direct dental restorations in anterior and posterior teeth. Systematic reviews and meta- analyses provide evidence that these composites can be successful, contingent on the skill, knowledge, and experience of the clinician. In the posterior dentition, however, composites still have a lower success rate compared to dental amalgam, which can be placed in bulk and sets quickly without dimensional change. See Maciel C.M. et al., Longevity of Resin Composite and Amalgam Posterior Restorations: A Systematic Review; European Journal of Prosthodontics and Restorative Dentistry Apr 042022

[0010] The workflow for composite restorations is more extensive and detailed than for amalgam, and errors at any step of this workflow can expedite failure. The primary reasons for the replacement of dental composite restorations are recurrent caries and fractures of the restorative material. See Knobloch, L.A. et al., Fracture Toughness of Packable and Conventional Composite Materials. J Prosthet Dent. 2002; 88:307-313; Busato, A.L. et al., Clinical Evaluation of Atlas Page 2 of 20 Patent ApplicationPosterior Composite Restorations: 6-Year Results. Am J Dent.2001; 14:304- 308.; and Moraschini, V. et al., Amalgam and Resin Composite Longevity of Posterior Restorations: A Systematic Review and Meta-Analysis. J Dent.2015; 43:1043-1050.

[0011] Recurrent decay frequently results from gaps at the margins of the composite restoration, caused by volumetric shrinkage during the light curing or polymerization process. This contraction occurs as the composite transitions from a paste, or flowable, consistency to a solid material in seconds, while simultaneously bonding to the tooth structure. This phenomenon generates stress within the material and at the interface with the tooth substrate, emphasizing the importance of the placement method. Gaps or inconsistencies at the tooth-restoration interface will enhance bacterial colonization also leading to restoration failure. See Cenci, M. et al., Class II Resin Composite Res- torations with Two Polymerization Techniques: Relationship Between Mi- crotensile Bond Strength and Marginal Leakage. J Dent. 2005; 33:603-610; Opdam, N.J. et al., Longevity and Reasons for Failure of Sandwich and Total- Etch Posterior Resin Composite Restorations. J Adhes Dent.2007; 9:469-75.l Opdam, N.J. et al., Five Years Clinical Performance of Posterior Resin Composite Restorations Placed by Dental Students. J Dent.2002; 87:642–649; Palotie, U. et al., Longevity of 2 and 3 Surface Restorations in Posterior Teeth of 25 to 30 Year Olds Attending Public Dental Service – A 13-Year Observation. J Dent. 2017; 62:13; and Mazer, R.B. et al., Short Term Clinical Studies for Predicting Posterior Composite Performance. J Dent Res, 1992: 71-112.

[0012] As a result of the above observations, numerous placement techniques, in large part developed based on certain qualities and limitations of the materials, have been proposed for placing dental composites in, for example, class II cavity preparations. Figure 13 is a schematic illustration of proposed placement methods for placing dental composites in class II cavity preparations.

[0013] A preparation, or tooth preparation or cavity preparation technically is the mechanical alteration of a defective, injured, or diseased tooth such that placement of restorative material re-establishes normal form and function, including esthetic corrections, where indicated. In the past, most tooth Atlas Page 3 of 20 Patent Applicationpreparations required for amalgam, cast metal, and ceramic restorations were precise procedures, usually resulting in uniform depths, particular wall forms, and specific marginal configurations. The use of adhesive restorations, primarily composites and glass ionomers, has allowed a reduced degree of precision of tooth preparations. Many composite restorations may require only the removal of the defect (caries, fracture, or defective restorative material) and friable tooth structure for tooth preparation, without specific uniform depths, wall designs, retentive features or marginal forms. The terms preparation, or tooth preparation or cavity preparation are generally also used to reference the prepared tooth are together with the process of creating the same.

[0014] Embodiment A illustrates a multiple small increments process and embodiment B illustrates a conventional layered composite process, in both of which the composite material is either injected or applied with an instrument in increments or layers, each of which is individually hardened by polymerization activated with a DLCU (i.e. a curing light emitting radiation in the predominantly blue wavelength region (400–500 nm) of the electromagnetic spectrum). The restoration may be built up with a large number of layers of material or with fewer layers placed either horizontally, vertically or obliquely, with a suggested maximum thickness of 2 mm. This method has raised concerns about the cumulative layers effects on internal flexure of the tooth cusps creating residual strain within the tooth leading to cusp fracture. In the conventional layered composite process (B) the material is warmed to approximately 50–70°C prior to injection. The warmed material may be used as the first layer only or for each layer of the restoration. These processes can lead to enamel cracks from polymerization shrinkage stress.

[0015] Embodiment C may be described as a conventional composite layered over flowable liner (including the “snowplow technique”). This method is similar to the conventional layered composite, with the difference being that a flowable composite liner is applied as the first thin increment. A flowable composite in the industry, and in this application, references a relatively low viscosity composite that flows relatively freely (before curing) and is thus self-leveling. This increment is pre-cured prior to the placement of the conventional composite (the conventional composite herein referencing a higher viscosity Atlas Page 4 of 20 Patent Applicationproduct than the flowable composite and a more paste type product before curing). The snowplow technique is similar, but in this case the flowable liner is not light-cured before applying the first increment of the conventional composite. Upon dispensing the conventional composite, the uncured flowable material further disperses into a very thin layer. The two composite materials are simultaneously polymerized with a single application of the DLCU. Few studies evaluate clinical performance of snowplow technique and none provide convincing evidence for its wide adoption.

[0016] Embodiment D may be described as a flowable bulk-fill liner composite with conventional composite capping layer. In this process a flowable composite, designed to be placed and cured in bulk, that is, in increments typically up to 4 mm, is dispensed as the first increment in the preparation, light cured, and then covered with a capping layer of conventional composite that is subsequently light cured. Here gap formation is dependent upon the flowable bulk fill used.

[0017] Embodiment E may be described as a Bulk-fill restorative, including sonic energy application and dual cure. Here a composite designed with properties similar to those of conventional composites but with enhanced optical properties to allow curing in bulk (typically up to 4 mm in depth), is injected into the cavity preparation in one or two increments, depending on the depth of the cavity preparation. In one system, a specially designed hand piece is used to provide sonic energy to dispense the material directly into the cavity preparation. There is no difference in performance established with this process. Dual-cure composites have also been developed for complete bulk- filling of restorations of any depth in a single increment, polymerized by a combination of light-curing and self-curing.

[0018] As a summary of the above during the placement of resin composite in known processes and subsequent light curing, the polymerization of resin composites can lead to shrinkage. This shrinkage may cause stresses that jeopardize the integrity of the tooth structure and bonded interfaces. Shrinkage stresses have also been associated with clinical issues such as cuspal flexure, enamel crack propagation, post-operative sensitivity, gaps, and secondary caries. The filling technique used when placing a resin composite restoration Atlas Page 5 of 20 Patent Applicationsignificantly affects the amount of residual shrinkage stress. Various techniques have been proposed to control this stress.

[0019] As discussed above one such technique is the bulk filling method, which involves restoring a posterior cavity preparation with a single increment of composite material. Some studies have shown that bulk filling, regardless of the composite material used, has a higher incidence of causing new enamel cracks due to polymerization shrinkage. Alternatively, some studies claim that applying the resin composite in increments rather than in bulk can decrease shrinkage stress. However, other research indicates that composite deformation caused by incremental filling can lead to higher shrinkage stresses. Additionally, it has been shown that horizontal increments result in higher residual stresses than oblique increments.

[0020] Despite discrepancy on preferred methodology, it is clear the placement technique can significantly impact the clinical success of a composite restoration. The bulk filling technique, which involves placing the composite in one single increment, reduces clinical steps and time while causing lower cuspal strains, stresses, and cuspal displacements. However, this method could potentially increase the incidence of new enamel cracks due to the high strain rate. Horizontal incremental filling techniques may result in higher cuspal strains, stresses, and cuspal displacements. The oblique incremental filling technique, although potentially reducing stresses compared to the horizontal method, requires more time and still creates stress on the tooth structure. The goal for the restorative dentist is to use a filling technique that proficiently reduces stress on the bonded interfaces to prevent failure while being efficient in time allocation by minimizing increments.

[0021] The desire to use composite for aesthetic and other rational results in an ongoing need for an improved dental composite placement protocol which is effective and efficient. SUMMARY OF THE INVENTION The present invention meets all the prerequisites for a successful composite restoration for class 1, 2 and 5 restorations. One aspect of the present invention provides a dental composite placement protocol for a composite restoration of Atlas Page 6 of 20 Patent Applicationa tooth comprising the steps of: providing a flowable composite as a dentin replacement on a pulpal floor and gingival box of a preparation and having a thickness of about 0.5 mm to about 4.0 mm; curing the flowable composite; providing a first increment layer of paste-type composite resin placed against the cured flowable composite, which first increment is a minimum of about 1.0 mm thick, and wherein the first increment layer of paste-type composite resin fully encapsulates preparation walls which includes the circumference of an entire cavosurface enamel margin of the preparation, including the interproximal enamel, and axial wall dentin, and optional matrix band; providing a stress relieving space in a middle of the preparation walls and the first increment layer, configured for allowing the composite forming the first increment layer to flow without constraint during curing; curing the first increment layer of paste-type composite resin; providing a final increment layer of paste-type composite resin placed in the remaining space including the stress relieving space and against the light-cured flowable composite and against the light-cured first increment, and wherein the a final increment layer of paste-type composite resin is placed against cured composite an not against tooth substrates; and curing the final increment layer of paste-type composite resin.

[0022] The present invention provides a streamlined three-step approach which begins with using a flowable composite as the dentin replacement on the pulpal floor and gingival box (if it is a Class 2 restoration) of the preparation. Depending on the depth of the cavity preparation and the specific type of flowable composite used, this layer can range from 0.5 mm to 4.0 mm and should be light cured with a DLCU for 10 seconds. Regardless of the clinical circumstance, the amount of flowable placed should allow for a minimum 2.0 mm depth for the next two vertical increments. These increments represent the enamel replacement and form the distinctive steps of this filling technique.

[0023] The first increment is a minimum 1.0 mm thick layer of paste-type composite resin placed against the cured flowable composite. It encapsulates the circumference of the entire cavosurface enamel margin of the preparation, including the interproximal enamel, axial wall dentin, and a matrix band (if performing a Class 2 composite restoration). This circumferential placement Atlas Page 7 of 20 Patent Applicationleaves a space in the middle of the preparation walls, allowing the composite to flow without constraint when light polymerized with a DLCU for 10 seconds.

[0024] It is crucial to use a dental explorer placed at a right angle to the long axis of the tooth to remove any excess extending past the enamel margins before light curing. Whether it is a Class 1, 2, or 5 restoration, the first two increments seal the margins of the entire cavity preparation in the least stressed and constrained manner.

[0025] The third and final increment is condensed in the remaining space against the light-cured flowable composite and against the light-cured first increment placed against the cavity preparation enamel walls. This last increment is placed against cured composite rather than tooth substrates and light polymerized with a DLCU for 10 seconds. Although it is the most stressful increment in terms of the cavity preparation configuration, it is the smallest increment and has no negative effect on the tooth substrates and marginal adaptation.

[0026] One aspect of the present invention provides a dental restoration of a tooth comprising: a cured flowable composite positioned as a dentin replacement on a pulpal floor and gingival box of a preparation and having a thickness of about 0.5 mm to about 4.0 mm; a cured first increment layer of paste-type composite resin placed against the cured flowable composite, which first increment is a minimum of about 1.0 mm thick, and wherein the first increment layer of paste-type composite resin fully encapsulates preparation walls which includes the circumference of an entire cavosurface enamel margin of the preparation, including the interproximal enamel, and axial wall dentin, wherein the cured first increment layer is cured in the presence of a stress relieving space in a middle of the preparation walls and the first increment layer, configured for allowing the composite forming the first increment layer to flow without constraint during curing; and a cured final increment layer of paste-type composite resin placed in the remaining space including the stress relieving space and against the light-cured flowable composite and against the light- cured first increment, and wherein the a final increment layer of paste-type composite resin is placed against cured composite an not against tooth substrates Atlas Page 8 of 20 Patent Application

[0027] The protocol and resulting restoration of the present invention represents a simpler method to restore a tooth with composite resin that will enable the clinician to be more precise, productive and profitable as well as provide the patient with a better restoration for improved long term outcomes. These and other advantages of the present invention will be clarified in the brief description of the preferred embodiment taken together with the drawings in which like reference numerals represent like elements throughout. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figures 1 and 2 are sequential perspective schematic views of the provision of a flowable composite as the dentin replacement on the pulpal floor and gingival box of a preparation for a class 2 composite restoration according to the protocol of the present invention.

[0029] Figure 3 is a perspective schematic view of light curing with a DLCU of the flowable composite positioned in figures 1-2 for the class 2 composite restoration according to the protocol of the present invention.

[0030] Figures 4 and 5 are sequential perspective schematic views of the provision of a first increment layer of paste-type composite resin placed against the cured flowable composite fully encapsulating the preparation walls which includes the circumference of the entire cavosurface enamel margin of the preparation, including the interproximal enamel, axial wall dentin, and a matrix band for the class 2 composite restoration according to the protocol of the present invention.

[0031] Figure 6 is a perspective schematic view of providing a stress relieving space in the middle of the preparation walls and the first increment layer, configured for allowing the composite to flow without constraint during curing for the class 2 composite restoration according to the protocol of the present invention.

[0032] Figure 7 is a perspective schematic view of light curing with a DLCU of the first increment layer of paste-type composite resin positioned in figures 4-5 for the class 2 composite restoration according to the protocol of the present invention. Atlas Page 9 of 20 Patent Application

[0033] Figures 8, 9 and 10 are sequential perspective schematic views of the provision of a final increment layer of paste-type composite resin placed the remaining space against the light-cured flowable composite and against the light-cured first increment wherein the a final increment layer of paste-type composite resin is placed against cured composite an not against tooth substrates for the class 2 composite restoration according to the protocol of the present invention.

[0034] Figure 11 is a perspective schematic view of light curing with a DLCU of the final increment layer of paste-type composite resin positioned in figures 8- 10 for the class 2 composite restoration according to the protocol of the present invention.

[0035] Figure 12 is a perspective schematic view of restoration formed by the protocol of the present invention.

[0036] Figure 13 is a schematic illustration of proposed prior art placement methods for placing dental composites in class II cavity preparations.

[0037] Figure 14 is a schematic illustration of class 1, 2 and 5 preparations suitable for the protocol of the present invention.

[0038] Figure 15 is a schematic illustration of C factor of preparations. DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0039] The present invention provides an efficient and effective dental composite placement protocol and maximizes the possibility of an effective dental restorations 100 formed thereby. The protocol of the present invention, described in detail below, is suitable for Class 1, 2 and 5 restorations. Figure 14 is a schematic illustration of class 1, 2 and 5 preparations schematically illustrating a representative tooth 10 with cavity preparation 20, and each of these classes of composite restoration is suitable for the protocol of the present invention. Each of these classes is considered a high stress composite restoration.

[0040] One measure of the relative stress of a given restoration is known as a C-factor, schematically illustrated in figure 15, and operates by idealizing or representing a given restoration as a cube and calculating the ratio of the number of bonded, bound or constrained walls to the number of unbounded, Atlas Page 10 of 20 Patent Applicationunbonded, unconstrained or free walls. As shown, class 1, 2 and 5 are relatively high stress restorations essentially due to a large amount of constrained surface vs free surface in the restoration. As detailed below, the protocol of the present invention creates a low C-factor environment for the initial incremental layer 50 with precision composite placement of layer 50 and relief 60 to reduce stresses caused to the tooth structure 10 during light curing and minimize damage to the margins of the restoration 100 from removing excess composite by over finishing.

[0041] The details for the protocol of the invention below are shown relative to a class 2 restoration 100 (the hardest restoration) for the sake of illustration, but is equally applicable to class 1 and class 5 restorations. As detailed below the restoration 100 is formed of three composite 30, 50 and 70 components.

[0042] As noted the protocol of the invention is suitable for class 1, 2 and 5 restorations but is being illustrated in connection with a class 2 in the tooth 10 with missing tooth structure, such as a cavity, shown as a preparation 20.

[0043] Figures 1 and 2 are sequential perspective schematic views of the provision of a flowable composite 30 as the dentin replacement on the pulpal floor and gingival box of a preparation 20 for a class 2 composite restoration 100 according to the protocol of the present invention.

[0044] The present application does not address the prep work for creating the operative site or preparation 20 to form the restoration 100 of the present invention which is conventional and well known.

[0045] When using any resin-based restoratives, such as in the present invention, both isolation and accurate contact creation are essential for successful Class II outcomes. Commonly sectional and circumferential matrix systems (matrix band 22, in this case) are utilized for establishing work site isolation and proper contact. Here the matrix band 22 is designed to complement the natural anatomy of the tooth 10, working together to isolate, seal and shape the restoration 100 in the preparation 20.

[0046] Flowable composite 30 is a low viscosity, self-leveling composite applied with applicator 24 (generally a syringe with nozzle) providing a gap free, level base layer 30 for the restoration 100. SDR® FLOW+ brand composite from Dentsply Sirona is a suitable composite for composite 30, which has become a Atlas Page 11 of 20 Patent Applicationleading industry standard since its introduction over a decade ago. The SDR® FLOW+ brand composite is a combination of polymerizable dimethacrylate resins, polymerizable trimethacrylate resins, polymerizable urethane dimethacrylate, and colorants formed as synthetic inorganic iron oxides

[0047] Depending on the depth of the cavity preparation 20 and the specific type of flowable composite 30 used, this layer of composite 30 can range from about 0.5 mm to about 4.0 mm. The term “about” within the meaning of this application, unless otherwise specified, is + / - 10%. The amount of flowable composite 30 placed should allow for a minimum about 2.0 mm depth for the next two vertical composite increments or components 50 and 70.

[0048] Figure 3 is a perspective schematic view of light curing with light source or DLCU 40 of the flowable composite 30 positioned (in figures 1-2) for the class 2 composite restoration 100 according to the protocol of the present invention. The flowable composite 30 should be light cured with Dental Curing Light Unit (DCLU) 40 for about 10 seconds.

[0049] As background the American Dental Association in regard to DCLU 40 notes that the “Dental light curing units are handheld light-emitting devices used to cure such photo-activated, polymer-based restorative materials. Dental professionals spend considerable time performing tasks that involve using PBRMs, and the convenience of being able to rapidly light cure these dental materials has transformed dentistry over time. In the contemporary marketplace, there are a wide variety of dental light curing units, and the technology has developed continually since photo-curing was first used in dentistry.” It should be noted that they are also references as dental light curing units or dental curing light units, and these are interchangeable herein. There are a variety of DCLU 40 available on the market and the DCLU 40 in the protocol of the invention is preferably a low profile LED based dental curing light unit to provide easy access to the area 20 in tooth 10.

[0050] The next two increments represent the enamel replacement and form the distinctive steps of this filling technique of the present protocol. The first increment is a minimum of about 1.0 mm thick layer of paste-type composite resin 50 placed via applicator 44 against the cured flowable composite 30. Composite 50 encapsulates the circumference of the entire cavosurface Atlas Page 12 of 20 Patent Applicationenamel margin of the preparation 20, including the interproximal enamel, axial wall dentin, and a matrix band 22. Figures 4 and 5 are sequential perspective schematic views of the provision of a first increment layer of paste-type composite resin 50 placed by applicator 44 against the cured flowable composite 30. The composite 50 may be compacted and positioned with dental tool(s) 46 to fully encapsulate the preparation 20 walls which includes the circumference of the entire cavosurface enamel margin of the preparation 20, including the interproximal enamel, axial wall dentin, and the matrix band 22 for the class 2 composite restoration 100 according to the protocol of the present invention. The composite 50 is firm and packable and a higher viscosity than the flowable composite 30 (meaning composite 50 has a higher viscosity than the composite 30 before curing of composite 30).

[0051] Preferably the uncured composite 50 doesn’t stick to hand instruments or tools 46, and adapts easily to cavity preparation 20 surfaces, is relatively easy to sculpt and shape, and exhibits “excellent slump resistance”. The TPH SPECTRA® family of composites from Dentsply Sirona is a suitable composite for composite 50 and comprises Urethane modified Bis-GMA dimethacralate; 2, 6-di-tert-butyl-p-cresol; Polymerizable dimethacrylate resin; Ytterbium trifluoride; Ethoxylated Bisphenol A Dimethacrylate; and colorants formed as inorganic iron oxides and titanium dioxide.

[0052] Figure 6 is a perspective schematic view of providing a stress relieving space 60 in the middle of the preparation walls and of the first increment layer 50, configured for allowing the composite 50 to flow without constraint during curing for the class 2 composite restoration 100 according to the protocol of the present invention. The perimeter of the space 60 will roughly follow the cavity preparation 20 walls and creates a low C-factor environment for the initial incremental layer 50 with precision composite placement of layer 50 to reduce stresses caused to the structure of the tooth 10 structure during light curing of curing of layer 50. The relief space 60 is formed with tools 48 and may be an oval, ellipse or other structure just very generally creating a uniform thickness to layer 50 (for precision the generally creating a uniform thickness defines the thickness of the layer 50 is + / - 75% of the average, more preferably + / - 50%, and even more preferably + / - 25% of the average, and most preferably + / - 10% Atlas Page 13 of 20 Patent Applicationof the average) and an unbounded surface generally parallel to the walls of the cavity preparation 20.

[0053] Figure 7 is a perspective schematic view of light curing with light source or DLCU 40 of the composite 50 positioned (in figures 3-4) with stress relieving recess 60 (Figure 6) for the class 2 composite restoration 100 according to the protocol of the present invention. The composite 50 should be light cured with DCLU 40 for about 10 seconds.

[0054] Figures 8, 9 and 10 are sequential perspective schematic views of the provision of a final increment layer of paste-type composite resin 70 placed in the remaining space via applicator 64 against the light-cured flowable composite 30 and against the light-cured first increment composite 50. The final increment layer of paste-type composite resin 70 is placed against cured composites 30 and 50 and not against tooth substrates of tooth 20 for the class 2 composite restoration according to the protocol of the present invention. The composite material 70 may be the same or similar to the composite 50 and compacted and shaped with tools 66 (or other hand tools as desired). As noted above in connection with composite 50, the uncured composite 70 doesn’t stick to hand instruments or tools 66, and adapts easily to composite 30 and 50 surfaces, is relatively easy to sculpt and shape, and exhibits “excellent slump resistance”. The TPH SPECTRA® family of composites from Dentsply Sirona is a suitable composite for composite 70.

[0055] It should be noted that composite restoration, like restoration 100 (formed collectively by composite 30, 50 and 70), is selected often for the aesthetic value. The earlier figures have enhanced the contrast between composite 30, 50, 70 and tooth structure 10 for illustration of the protocol, while figure 10 illustrates a more accurate and desirable outcome with virtually no visible delineation between composite 50 and 70 and, hopefully, the tooth 10.

[0056] Figure 11 is a perspective schematic view of light curing with light source or DLCU 40 of the composite 70 positioned (in figures 8-10) on composites 30 and 50 and avoiding tooth structure contact for the class 2 composite restoration 100 according to the protocol of the present invention. The composite 70 should be light cured with DLCU 40 for about 10 seconds. Atlas Page 14 of 20 Patent Application

[0057] Figure 12 is a perspective schematic view of restoration 100 formed by the protocol of the present invention with the matrix system 22 being removed.

[0058] The above description illustrates a class 2 restoration 100 according to the present protocol. The protocol is equally applicable to class 1 and 5 preparations 20, which generally do not require a matrix system 22. The patient may be orientated such that the base or floor of the preparation 20 is generally horizontal (i.e. a class 5 preparation 20 may have the patient lie back in the chair and turn to one side or the other to orientate the preparation 20 “vertically”.) The protocol begins with the provision of the flowable composite 30 on the floor of the preparation 20 (i.e. the pulpal floor for class 5) then to the application of the first increment paste composite 50 in a 1-2 mm thick increment (depending upon the width of the preparation 20) circumferentially around the periphery of the preparation 20 and at least 2 mm in depth for a class 1 restoration leaving a space 60 in the middle to allow the composite 50 to flow as it's being light cured. The depth is less significant for a class 5 as it is not in occlusion and not a recipient of direct masticatory forces and food. The last increment of composite 70 is against cured composites 30 and 50 and not tooth structure 10 creating less stress to the tooth structure 10 and cusps.

[0059] Although the present invention has been described with particularity herein, the scope of the present invention is not limited to the specific embodiment disclosed. It will be apparent to those of ordinary skill in the art that various modifications may be made to the present invention without departing from the spirit and scope thereof. The scope of the present invention should be defined by the appended claims and equivalents thereto. Atlas Page 15 of 20 Patent Application

Claims

What is claimed is:

1. A dental composite placement protocol for a composite restoration of a tooth comprising the steps of: providing a flowable composite as a dentin replacement on a pulpal floor and gingival box of a preparation and having a thickness of about 0.5 mm to about 4.0 mm; curing the flowable composite; providing a first increment layer of paste-type composite resin placed against the cured flowable composite, which first increment is a minimum of about 1.0 mm thick, and wherein the first increment layer of paste-type composite resin fully encapsulates preparation walls which includes the circumference of an entire cavosurface enamel margin of the preparation, including the interproximal enamel, and axial wall dentin, and optional matrix band; providing a stress relieving space in a middle of the preparation walls and the first increment layer, configured for allowing the composite forming the first increment layer to flow without constraint during curing; curing the first increment layer of paste-type composite resin; providing a final increment layer of paste-type composite resin placed in the remaining space including the stress relieving space and against the light- cured flowable composite and against the light-cured first increment, and wherein the a final increment layer of paste-type composite resin is placed against cured composite an not against tooth substrates; and curing the final increment layer of paste-type composite resin.

2. The dental composite placement protocol for a composite restoration of a tooth according to claim 1, wherein the curing is performed with a dental curing light unit.

3. The dental composite placement protocol for a composite restoration of a tooth according to claim 2, wherein a matrix band is utilized.

4. The dental composite placement protocol for a composite restoration of a tooth according to claim 3, wherein the first increment layer and the final increment layer have a minimum of about 2.0 mm depth. Atlas Page 16 of 20 Patent Application5. The dental composite placement protocol for a composite restoration of a tooth according to claim 4, wherein the first increment layer is compacted and positioned with at least one dental tool.

6. The dental composite placement protocol for a composite restoration of a tooth according to claim 4, wherein the first increment layer is firm and packable and a higher viscosity than the flowable composite before curing.

7. The dental composite placement protocol for a composite restoration of a tooth according to claim 4, wherein the stress relieving space in a middle of the preparation walls and the first increment layer follows the cavity preparation walls and creates a low C-factor environment for the initial incremental layer.

8. The dental composite placement protocol for a composite restoration of a tooth according to claim 1, wherein the first increment layer and the final increment layer have a minimum of about 2.0 mm depth.

9. The dental composite placement protocol for a composite restoration of a tooth according to claim 8, wherein the first increment layer is compacted and positioned with at least one dental tool.

10. The dental composite placement protocol for a composite restoration of a tooth according to claim 8, wherein the first increment layer is firm and packable and a higher viscosity than the flowable composite before curing.

11. The dental composite placement protocol for a composite restoration of a tooth according to claim 8, wherein the stress relieving space in a middle of the preparation walls and the first increment layer follows the cavity preparation walls and creates a low C-factor environment for the initial incremental layer.

12. The dental composite placement protocol for a composite restoration of a tooth according to claim 1, wherein the first increment layer is compacted and positioned with at least one dental tool.

13. The dental composite placement protocol for a composite restoration of a tooth according to claim 1, wherein the first increment layer is firm and packable and a higher viscosity than the flowable composite before curing. Atlas Page 17 of 20 Patent Application14. The dental composite placement protocol for a composite restoration of a tooth according to claim 1, wherein the stress relieving space in a middle of the preparation walls and the first increment layer follows the cavity preparation walls and creates a low C-factor environment for the initial incremental layer.

15. A dental restoration formed by the protocol of claim 1.

16. A dental restoration of a tooth comprising: a cured flowable composite positioned as a dentin replacement on a pulpal floor and gingival box of a preparation and having a thickness of about 0.5 mm to about 4.0 mm; a cured first increment layer of paste-type composite resin placed against the cured flowable composite, which first increment is a minimum of about 1.0 mm thick, and wherein the first increment layer of paste-type composite resin fully encapsulates preparation walls which includes the circumference of an entire cavosurface enamel margin of the preparation, including the interproximal enamel, and axial wall dentin, wherein the cured first increment layer is cured in the presence of a stress relieving space in a middle of the preparation walls and the first increment layer, configured for allowing the composite forming the first increment layer to flow without constraint during curing; and a cured final increment layer of paste-type composite resin placed in the remaining space including the stress relieving space and against the light-cured flowable composite and against the light-cured first increment, and wherein the a final increment layer of paste-type composite resin is placed against cured composite an not against tooth substrates.

17. The dental restoration according to claim 16, wherein the first increment layer and the final increment layer have a minimum of about 2.0 mm depth.

18. The dental restoration according to claim 17, wherein the stress relieving space in a middle of the preparation walls and the first increment layer follows the cavity preparation walls and creates a low C-factor environment for the initial incremental layer.

19. The dental restoration according to claim 17, wherein the first increment layer follows the cavity preparation walls. Atlas Page 18 of 20 Patent Application20. The dental restoration according to claim 17, wherein the cured flowable composite has a thickness of 0.5 mm to 4.0 mm. Atlas Page 19 of 20 Patent Application

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