Method and composition for adhering to tooth structure

A dental adhesive composition has an adhesive component and an activator component. The adhesive composition has a volatile organic solvent component, one or more polymerizable (meth)acrylate compounds optionally containing fillers, and a polymerization photoinitiator. The adhesive component may also be a substantially homogeneous mixture of one or more polymerizable (meth)acrylate compounds and an effective amount of a photoinitiator, without a solvent. The activator component includes an aromatic sulfinate salt and an activator component solvent. A method for adhering a restorative to a dental surface includes preparing the surface for restoration; applying a mixture of an adhesive component and an activator component to the prepared cavity, thereby forming a coated cavity surface; and, applying a direct or indirect dental restorative to the coated cavity surface.

EXAMPLE 1 This inventive composition was tested for shear bond strength (SBS) using a Single Plane Shear Test Assembly apparatus (SPSTA) as described by L. G. Watanabe, et al., in Journal of Dental Research, 76 (Special Edition) Abs. 1398, 1977 and/or other standard compressive shear bond strength test methods as described in U.S. Pat. No. 5,645,429 which is hereby incorporated by reference for such disclosure, and for example, in Dental Materials, vol. 3;185, 1987 by Hammesfahr et al. The compositions tested included self curing (SC) and light curing (LC or VLC for “visible light cure”) materials. Further, the inventive materials were tested with etching or non-etching to dental surfaces as will be noted below, and were also compared to various commercially available adhesive products. As will be shown in the following tables, the inventive material shows comparable or improved results over the commercially available products. “SD” as used below is standard deviation, and “Del.” is dentin or enamel delamination. Cohesive failure as reported indicate bond fracture occurred within either tooth substrate dentin or enamel or restoratives and are reported as the number of failures (F) per the total number tested (T) (F/T). Both immediate (15 minute) and 24-hour bond strength of different composite resin luting cements to human dentin using the inventive composition or other commercially available dual-cure adhesive systems were evaluated by SPSTA test methods as described above. The results are summarized in TABLE I. 1 TABLE I System Comparison* of The Inventive Composition Immediate (15 minute) and 24 Hours Shear Bond Strength** Dual-Cure Universal Immediate SBS (MPa) 24 Hrs SBS (MPa) Dental Adhesive Systems X ± SD, Dentin Del (%) X ± SD, Dentin Del (%) Comments Dual-Cure Prime & Bond ™ 2.1 6.72 ± 2.38 20% 10.32 ± 1.75 40% total SC (Dentsply/Caulk) (total SC) &gE;13.97 ± 0.96 100% Enforce LC 1′ 8.53 ± 1.98 0% 15.47 ± 2.27 75% Primers LC 10″ (total SC) &gE;13.67 ± 2.64 100% LC both Primers and Enforce SBMP&plus; 4.98 ± 1.00 20% 6.36 ± 2.71 20% total SC (per DFU) (3M) 8.98 ± 3.05 0% LC 10″ Activator/Primer All-Bond 2 9.15 ± 0.73 60% 11.89 ± 2.91 80% Primers LC 20″ (BISCO, Inc.) (per DFU) OptiBond 8.22 ± 3.70 0% 7.68 ± 1.72 0% Nexus Cement LC 1′ (Ker) (per DFU) *All the test samples for different system were prepared according to the manufacturer's directions for use (DFU), and the manufacturer's recommended resin cement was used for different system, i.e. the inventive composition/EnForce WF (Caulk), SBMP&plus;/3M Resin Cement (3M), All-Bond 2/Duo-Link (BISCO, Inc.), and OptiBond/Nexus (Kerr). **SBS was tested using Single Plane Shear Test Assembly. As indicated by the SBS data, the inventive composition, two-bottle dual-cure dental adhesive system showed equivalent (or improved) bonding performance to competitors' multi-bottle dental adhesive system (3M's SBMP&plus;, Bisco's All-Bond and Kerr's OptiBond), with the additional advantages of simplicity, i.e. simple technique, less total application time, time/cost saving, fluoride-release, thin-film thickness, and the like. 
 EXAMPLE II Using the SPSTA test method, bond strength of different restorative materials to human teeth (dentin) using the inventive composition was evaluated and the results are shown in TABLE II. 2 TABLE II 24 hr. Shear Bond Strength of Different Restoratives to Human Teeth Using The Inventive Composition BONDING SURFACE Inventive 24 Hour SUBSTRATE TREATMENT Composition RESTORATIVES Shear Bond Strength (MPa) Dentin Etched Self Cure (SC) SC Enforce ™ WF 11.20 ± 2.58 80% Dentin Etched Visible Light SC Enforce ™ WF 13.93 ± 1.81 75% Cure (VLC) Dentin Etched Visible Light SC Enforce ™ WF 15.47 ± 2.27 75% Cure (VLC) Dentin Etched Visible Light VLC Enforce ™ WF &gE;13.67 ± 2.64 100% Cure (VLC) Dentin Unetched Self Cure (SC) SC Enforce ™ WF 4.18 ± 2.91 0% Dentin Unetched Visible Light SC Enforce ™ WF 9.79 ± 3.0 60% Cure (VLC) Dentin Etched Self Cure (SC) SC FluoroCore ™ 8.90 ± 3.0 33% Dentin Etched Visible Light VLC TPH ™ 31.34 ± 3.82 10% Cure (VLC) Spectrum Composite As can be seen from the SBS results in TABLE II (and TABLE III below) the inventive composition can be used to adhere different restorative materials to tooth structure in a variety of direct and indirect restoration applications with good bonding performance. 
 EXAMPLE III Using the SBS test method as described in Dental Materials, Vol. 3;185, 1987, and in the incorporated U.S. Pat. No. 5,645,429, 24-hour enamel SBS of different restoratives used in direct and/or indirect restorations using the inventive composition was evaluated. The results are summarized in TABLE III. 3 TABLE III 24 Hour SBS* of Different Restoratives to Human Tooth Using the Inventive Composition BONDING SURFACE INVENTIVE 24 Hrs. SBS (MPa) SUBSTRATE TREATMENT COMPOSITION RESTORATIVES X ± SD: Enamel Del (%) Enamel Etched Self Cure (SC) 1 SC Enforce ™ WF 1 26.8 ± 4.7 100% Enamel Etched Visible Light Cure 2 (VLC) VLC Enforce ™ WF 2 23.7 ± 4.8 100% Enamel Etched Visible Light Cure 3 (VLC) VLC TPH ™ 31.0 ± 8.0 80% Spectrum Composite 3 *SBS was tested using Caulk's Compressive Shear Bond Strength Test Method 1 Bonding Protocol-1(total SC): Etched Enamel (Caulk 34% tooth gel/15″)/P & B 2.1 & SC Activator (1/1 premix) &lsqb;1C/wet, NC&rsqb;/Enforce(SC) 2 Bonding Protocol-2: Etched Enamel (Caulk 34% tooth gel 15″)/P & B 2.1 & SC Activator (1/1 premix) &lsqb;1C/wet, LC 10″&rsqb;/Enforce(LC 40″) 3 Bonding Protocol-3: Etched Enamel (Caulk 34% tooth gel 15″)/P & B 2.1 & SC Activator (1/1 premix) &lsqb;1C/wet, LC 10″&rsqb;/TPH Spectrum (LC 40″) As indicated by the 24 hour enamel SBS data in TABLE III, the inventive composition as a 2-bottle dual cure dental adhesive system showed very good bonding performance (up to 31 MPa, with 100% cohesive failure within human enamel) to human enamel (even in total self cure mode) in relevant to direct and indirect dental applications. 
 EXAMPLE IV Using the SBS test method as in Example III, except that a porcelain substrate is used in place of human enamel, 24 hour SBS of Enforce Resin Cement to an all-ceramic substrate (commercially available from DENTSPLY International Inc.) using the inventive composition was tested. The obtained results are shown in TABLE IV, indicated that the inventive composition can be used to adhere to a porcelain substrate with high bond strength. 4 TABLE IV 24 Hour SBS* of Enforce WF (B1) Cement to All-Ceramic Substrate Using the Inventive Composition Bonding Substrate Bonding Protocol X ± SD: &num; Coh  (MPa) Porcelain Control: substrate porcelain (microetched w/50 &mgr;m alumina, then silanated per DFU)/Enforce WF 12.5 ± 3.9; 0/6 &lsqb;B1&rsqb;(1/1)(LC) Porcelain substrate porcelain (microetched, then silanated per DFU)/P & B 2.1 & SCA (1/1 mix) &lsqb;C/NC&rsqb;/Enforce WF 14.8 ± 4.1; 0/7 &lsqb;B1&rsqb;(1/1)(SC) Porcelain Substrate porcelain (microetched, then silanated per DFU)/P & B 2.1 & SCA (1/1 mix) &lsqb;C/LC&rsqb;/Enforce WF 25.0 ± 6.6; 6C/6 (Substrate &lsqb;B1&rsqb;(1/1)(LC) porcelain) Porcelain Substrate porcelain (Microetched, HF etched/60″, then silanated)/Enforce WF &lsqb;B1&rsqb;(1/1)(LC) 11.1 ± 5.0; 4C/5 (Substrate porcelain) Porcelain Substrate porcelain (Microetched, HF etched/60″, silanated)/P & B 2.1 (1/1 mix) &lsqb;C/NC&rsqb;/Enforce WF 20.7 ± 3,51; 5C.5 (Substrate &lsqb;B1&rsqb;(1/1)(SC) porcelain) *SBS was tested using Caulk's Compressive Shear Bond Strength Test Method. 5 TABLE V 24 hr. SBS of Non-Precious Metal (Rexillium III) to Etched Human Enamel Using the Inventive Composition and Enforce WF (Opaque)* Bonding Substrate Bonding Protocol X ± SD (MPa) Fracture Mode Enamel Enamel (34% Gel/30″)/Prime & Bond 2.1 & SC Activator (1C/wet, 23.2 ± 15.4 33% enamel coh. Fail, NC)/Enforce w/F &lsqb;OP&rsqb;(1/1) (SC mode) others adh/coh mixed. (1L, SC 6′, LC 3 × 20″)/Rex III &lsqb;microetched, Prime & Bond 2.1 SC Activator (1C/wet, LC 10″)&rsqb; Enamel Enamel (34% Gel/30″)/Prime & Bond 2.1 & SC Activator (1C/wet, 13.1 ± 9.4 Mixed failure LC 10″)/Enforce w/F &lsqb;OP&rsqb;(1/1) (Add LC) (Cement) Coh/adh. (1L, SC 6′, LC 3 × 20″)/Rex III &lsqb;microetched, Prime & Bond 2.1 & SC Activator (1C/wet, LC 10″)&rsqb; *SBS was tested by Caulk's Compressive Shear Bond Strength Test Method where 3.15 mm Rexillium III Post used 6 TABLE VI 24 Hour Shear Bond Strengh* of Fresh Amalgam with Human Dentin Sample Bonding Protocol X (SD), &num;Del. Prime & Bond ® 2.1 Etched dentin (Caulk gel/15″)/P & B 2.1 & SC Activator (1/1 premix) &lsqb;1C/wet, NC&rsqb;/Caulk SC 4.1 (1.3), 0/5 Dual Cure Adhesive Bonding Agent Base/catalyst (1/1 equal drop mix) &lsqb;1L, SC&rsqb;/Dispersalloy ® amalgam SBMP&plus; Etched dentin (3M etchang/15″)/Activator/Primer &lsqb;1C, NC&rsqb;/Adhesive & Catalyst (1/1 mix) 2.2 (0.9), 0/5 &lsqb;1 Thin Layer, SC&rsqb;/Dispersalloy ® amalgam Per DFU SBMP&plus; Repeat amalgam bonding, per DFU 3.7 (0.2), 0/5 OptiBond ® Per DFU: Etched (Kerr's etching/15″)/Primer 1 &lsqb;C/scrub 30″, NC&rsqb;/Adhesive 2 &lsqb;1 thin Layer; 1.8 (1.9), 0/5 LC 30″&rsqb;/Dispersalloy ® amalgam All-Bond ® 2 Per DFU: Etched dentin (Uni-Etch/15″)/Primer P & B (1/1 mix) &lsqb;5C, LC 20″&rsqb;/Pre-Bond & D/E 2.6 (1.8), 0/5 Bond (1/1 mix) &lsqb;1 Thin Layer, SC&rsqb;/Dispersalloy ® amalgam Amalgam Bond Plus Unetched dentin/Activator/ahd. Agent/Mix (base/cat/HPA) &lsqb;1L, SC&rsqb;/Dispersalloy ® amalgam 6.5 (1.7), 0/5 w/HPA Per DFU Amalgam Bond Plus Unetched dentin/Activator/adh. agent/Mix (base & cat) &lsqb;1L, SC&rsqb;/Dispersalloy ® amalgam 2.4 (1.8), 0/5 w/o HPA →1.7 (0.6), 0/5 ←(repeated BS) *SBS was tested using Single Plane Shear Test Assembly It is apparent therefore, that the dental compositions as described herein are effective in carrying out the objects of the invention. While the principles of the invention have been made clear by the illustrative embodiments discussed, those skilled in the art will appreciate that modifications to composition components including the addition of other components to the composition for promoting chemical or photocure polymerization, amounts, grades, process and method conditions and the like, can be made and still fall within the scope of the those principles and of the invention.