Hydrophilic endodontic sealing compositions and methods for using such compositions

Abstract

Endodontic sealant compositions and methods for sealing a root canal using sealant or other filling materials. The compositions include one or more resins that promote adhesion to hydrophilic dental tissues. Examples include alkyl methacrylates and derivatives thereof, such as alkylamino acrylates and methacrylates, oxyphosphoro acrylates and methacrylates, and acrylates and methacrylates substituted with oxysulfur, borate, carboxylic acid, or cyano groups or derivatives. The compositions include a radio opacifying agent, so that they may be seen using X-rays, and one or more polymerization initiators to effect curing, at least one chemical initiator and, optionally, a photoinitiator, to yield a curable sealant composition. The compositions are introduced into the root canal using a narrow cannula coupled to a high pressure hydraulic delivery device. Additional pressure may be applied to the sealant compositions using a syringe-like plunger introduced within a cylindrical access hole drilled through the crown of the tooth. The chemical initiator causes the mixed composition to harden over time. Hardening of at least a portion of the composition can be accelerated by including a photoinitiator and irradiating the mixed composition with radiant energy (e.g., from a dental curing lamp).

What is claimed and desired to be secured by United States Letters Patent is:  
     
         1 . A multipart endodontic filling and sealing composition comprising at least two initially separate parts which, upon mixing the parts together, form a mixed composition which is initially flowable and suitable for placement into a root canal during a root canal procedure and which hardens over a time, the multipart endodontic composition including: 
 a polymerizable resin portion contained in at least one of the initially separate parts, the polymerizable resin portion including a polymerizable adhesive resin that includes at least one of an alkyl acrylate or alkyl methacrylate and that is capable of bonding to dental tissue found within a root canal, wherein the at least one alkyl acrylate or alkyl methacrylate is substituted with at least one of an oxysulfur radical, borate radical, carboxyl radical, nitro radical, or cyano radical; and    at least one chemical initiator contained in at least one of the initially separate parts which, upon mixing the parts together, causes at least a portion of the polymerizable resin portion to polymerize over a period of time.    
     
     
         2 . A multipart endodontic filling and sealing composition as defined in  claim 1 , wherein the at least one of alkyl acrylate or alkyl methacrylate is substituted with at least one oxysulfur radical selected from the group consisting of:  
       
         
           
           
               
               
           
         
         wherein R comprises a hydroxyl, alkyl, or alkoxy radical.  
       
     
     
         3 . A multipart endodontic filling and sealing composition as defined in  claim 1 , wherein the at least one of alkyl acrylate or alkyl methacrylate is substituted with at least one borate radical selected from the group consisting of:  
       
         
           
           
               
               
           
         
         wherein R 1  and R 2  may variously comprises a hydrogen or alkyl radical.  
       
     
     
         4 . A multipart endodontic filling and sealing composition as defined in  claim 1 , wherein the at least one of alkyl acrylate or alkyl methacrylate is substituted with at least one carboxyl radical in addition to any acrylate or methacrylate ester groups, the at least one carboxyl radical having the general formula:  
       
         
           
           
               
               
           
         
         wherein R comprises a hydroxyl, alkoxy, or amino radical, the amino radical, if included at all, having the generally formula:  
         
           
             
             
                 
                 
             
           
         
         wherein R 1  and R 2  may variously comprises a hydrogen or alkyl radical.  
       
     
     
         5 . A multipart endodontic filling and sealing composition as defined in  claim 1 , wherein the at least one of alkyl acrylate or alkyl methacrylate is substituted with at least one cyano radical selected from the group consisting of —CN, —NC, —CNO, and —NCO.  
     
     
         6 . A multipart endodontic filling and sealing composition as defined in  claim 1 , wherein the adhesive resin has a concentration in a range from about 0.01% to about 90% by total combined weight of the initially separate parts.  
     
     
         7 . A multipart endodontic filling and sealing composition as defined in  claim 1 , wherein the adhesive resin has a concentration in a range from about 0.5% to about 30% by total combined weight of the initially separate parts.  
     
     
         8 . A multipart endodontic filling and sealing composition as defined in  claim 1 , wherein the adhesive resin has a concentration in a range from about 1% to about 10% by total combined weight of the initially separate parts.  
     
     
         9 . A multipart endodontic filling and sealing composition as defined in  claim 1 , wherein the polymerizable resin portion further includes at least one additional polymerizable resin comprising at least one of an alkyl acrylate, an alkyl methacrylate, an alkyl hydroxy methacrylate, an alkyl amino methacrylate, or bisphenol-A-diglycidyl dimethacrylate.  
     
     
         10 . A multipart endodontic filling and sealing composition as defined in  claim 9 , wherein the at least one additional polymerizable resin has a concentration of up to about 95% by total combined weight of the initially separate parts.  
     
     
         11 . A multipart endodontic filling and sealing composition as defined in  claim 9 , wherein the at least one additional polymerizable resin has a concentration in a range from about 5% to about 80% by total combined weight of the initially separate parts.  
     
     
         12 . A multipart endodontic filling and sealing composition as defined in  claim 9 , wherein the at least one additional polymerizable resin has a concentration in a range from about 10% to about 70% by total combined weight of the initially separate parts.  
     
     
         13 . A multipart endodontic filling and sealing composition as defined in  claim 1 , wherein the at least one chemical initiator includes a plurality of initially separate and unmixed components, each component being contained in a different one of the at least two initially separate parts.  
     
     
         14 . A multipart endodontic filling and sealing composition as defined in  claim 13 , wherein the at least one chemical initiator includes a peroxide-based component contained in one of the at least two initially separate parts and an amino component contained in a different one of the at least two initially separate parts.  
     
     
         15 . A multipart endodontic filling and sealing composition as defined in  claim 14 , wherein the peroxide-based component includes at least one of benzoyl peroxide, 2-butanone peroxide, lauroyl peroxide, or tert-butyl peroxide.  
     
     
         16 . A multipart endodontic filling and sealing composition as defined in  claim 14 , wherein the amino component includes at least one of dimethylamino ethyl methacrylate, triethyl amine, 2-dimethylamino ethanol, diethylamino ethyl methacrylate, trihexyl amine, N,N-dimethyl-p-toluidine, N-methylethanolamine, or 2,2′(p-tolyimino) diethanol.  
     
     
         17 . A multipart endodontic filling and sealing composition as defined in  claim 1 , wherein the chemical initiator is included in an amount so that the polymerizable resin portion within the mixed composition cures in a time period of about 2 minutes to about 2 hours after mixing the parts together.  
     
     
         18 . A multipart endodontic filling and sealing composition as defined in  claim 1 , wherein the chemical initiator is included in an amount so that the polymerizable resin portion within the mixed composition cures in a time period of about 5 minutes to about 1 hour after mixing the parts together.  
     
     
         19 . A multipart endodontic filling and sealing composition as defined in  claim 1 , wherein the chemical initiator is included in an amount so that the polymerizable resin portion within the mixed composition cures in a time period of about 10 minutes to about 30 minutes after mixing the parts together.  
     
     
         20 . A multipart endodontic filling and sealing composition as defined in  claim 1 , further including at least one polymerization photoinitiator contained in at least one of the initially separate parts which, upon irradiating at least a portion of the mixed composition with radiant energy, causes accelerated polymerization and hardening of at least a portion of the polymerizable resin portion.  
     
     
         21 . A multipart endodontic filling and sealing composition as defined in  claim 20 , wherein the at least one polymerization photoinitiator includes at least one of camphor quinone, benzoin methyl ether, 2-hydroxy-2-methyl-1-phenyl-1-propanone, diphenyl 2,4,6-trimethylbenzoyl phosphine oxide, benzoin ethyl ether, benzophenone, or 9,10-anthraquinone.  
     
     
         22 . A multipart endodontic filling and sealing composition as defined in  claim 20 , characterized in that, upon irradiating the mixed composition with radiant energy, at least a portion of the mixed composition hardens within a time period of about 10 seconds to about 1 minute.  
     
     
         23 . A multipart endodontic filling and sealing composition as defined in  claim 1 , further including a radiopaque filler contained in at least one of the initially separate parts that comprises at least one of a bismuth salt, silver, a silver salt, a barium salt, a strontium salt, a tungsten-containing compound, or titanium dioxide.  
     
     
         24 . A multipart endodontic filling and sealing composition as defined in  claim 1 , further including at least one antimicrobial agent contained in at least one of the initially separate parts.  
     
     
         25 . An endodontic filling and sealing composition comprising the mixture products of: 
 a polymerizable resin portion contained in at least one of initially separate parts and including a polymerizable adhesive resin that includes at least one of an alkyl acrylate or alkyl methacrylate and capable of bonding to dental tissue found within a root canal, wherein the at least one alkyl acrylate or alkyl methacrylate is substituted with at least one of an oxysulfur radical, borate radical, carboxyl radical, nitro radical, or cyano radical; and    at least one chemical initiator contained in at least one of the initially separate parts which, upon mixing the parts together, causes at least a portion of the polymerizable resin portion to polymerize over a period of time.    
     
     
         26 . An endodontic filling and sealing composition as defined in  claim 25 , wherein the composition is characterized as hardening in a time period of about 10 minutes to about 30 minutes after mixing the polymerizable resin portion and chemical initiator together.  
     
     
         27 . An endodontic filling and sealing composition as defined in  claim 25 , further including at least one polymerization photoinitiator which, upon irradiating at least a portion of the composition with radiant energy, causes accelerated polymerization and hardening of at least a portion of the polymerizable resin portion.  
     
     
         28 . An endodontic filling and sealing composition as defined in  claim 27 , characterized in that, upon irradiating the composition with radiant energy, at least a portion of the composition hardens within a time period of about 10 seconds to 1 minute.  
     
     
         29 . A multipart endodontic filling and sealing composition comprising at least two initially separate parts which, upon mixing the parts together, form a mixed composition which is initially flowable and suitable for placement into a root canal during a root canal procedure and which hardens over time, the multipart endodontic composition consisting essentially of: 
 a polymerizable resin portion contained in at least one of the initially separate parts, the polymerizable resin portion including a polymerizable adhesive resin that includes at least one of an alkyl acrylate or alkyl methacrylate and that is capable of bonding to dental tissue found within a root canal, wherein the at least one alkyl acrylate or alkyl methacrylate is substituted with at least one of an oxysulfur radical, borate radical, carboxyl radical, nitro radical, or cyano radical;    at least one radiopaque filler contained in at least one of the initially separate parts;    at least one chemical initiator contained in at least one of the initially separate parts which, upon mixing the parts together, causes the mixed composition to harden within a time period of about 2 minutes to about 2 hours as a result of chemical curing; and    optionally, at least one polymerization photoinitiator contained in at least one of the initially separate parts which, upon irradiating at least a portion of the mixed composition with radiant energy, causes accelerated polymerization and hardening of at least a portion of the mixed composition.    
     
     
         30 . A multipart endodontic filling and sealing composition as defined in  claim 29 , wherein the at least one radiopaque filler comprises at least one of a bismuth salt, silver, a silver salt, a barium salt, a strontium salt, a tungsten-containing compound, or titanium dioxide.  
     
     
         31 . A method for treating a tooth following an endodontic procedure comprising: 
 providing a tooth that includes an access hole drilled into and extending through the crown of the tooth, said access hole providing access to at least one root canal of the tooth that has been cleaned by an endodontic procedure;    mixing together initially separate parts of a multipart endodontic composition to form a mixed composition which is initially flowable and suitable for placement into a root canal during a root canal procedure and which hardens over time, the mixed composition initially including: 
 a polymerizable resin portion including an adhesive resin that is at least one of an alkyl acrylate or alkyl methacrylate and capable of bonding to dental tissue found within a root canal, wherein the at least one alkyl acrylate or alkyl methacrylate is substituted with at least one of an oxysulfur radical, borate radical, carboxyl radical, nitro radical, or cyano radical; and  
 at least one chemical initiator which causes at least a portion of the polymerizable resin portion to polymerize over a period of time;  
   introducing the mixed composition into the at least one root canal of the tooth;    allowing the mixed composition to at least partially polymerize and harden within the root canal; and    filling the access hole with a filling material.    
     
     
         32 . A method for treating a tooth as defined in  claim 31 , wherein the filling material chemically bonds to an exposed portion of the mixed composition within the root canal.  
     
     
         33 . A method for treating a tooth as defined in  claim 31 , wherein the mixed composition is introduced into the root canal by means of a cannula sized to fit within the root canal and in fluid communication with a high pressure hydraulic system.  
     
     
         34 . A method for treating a tooth as defined in  claim 31 , further including applying additional pressure to the mixed composition after introducing it into the root canal.  
     
     
         35 . A method for treating a tooth as defined in  claim 34 , wherein the application of additional pressure is carried out by means of inserting an elastomeric plug into a said access hole and applying force to said plug in order to exert fluid pressure onto the mixed composition, said elastomeric plug being sized so as to form a substantially fluid-tight seal between said plug and dental tissue surrounding said access hole.  
     
     
         36 . A method for treating a tooth as defined in  claim 35 , wherein said elastomeric plug comprises gutta percha.  
     
     
         37 . A method for treating a tooth as defined in  claim 31 , wherein the mixed composition hardens in a time period of about 2 minutes to about 2 hours due to chemical curing.  
     
     
         38 . A method for treating a tooth as defined in  claim 31 , wherein the mixed composition further includes at least one polymerization photoinitiator, the method further comprising irradiating with radiant energy an exposed portion of the mixed composition within the root canal in order to polymerize and harden at least a portion of the mixed composition within a period of time of about 10 seconds to about 1 minute.