Dispensing syringe having multiple barrels for discharging a dental composition

Abstract

A dispensing syringe for dispensing a multi-component dental composition, preferably a two component composition, is provided. The syringe includes a syringe body with multiple elongated barrels for storing the components of the composition; a threaded plunger rod assembly; and a rotatable, threaded connector knob. Preferably, the syringe body has a double-barrel structure and the plunger rod assembly includes two plunger rods that slide within the barrels. The threaded knob has a through-bore with a continuous internal thread for engaging the outer threads of the first and second plunger rods. A dental practitioner manually rotates the knob to displace the first and second plunger rods and discharge the components. The dispensing syringe may further include a dispensing tip containing a static mixing element for mixing the components and dispensing the mixed composition.

1 . A dispensing syringe for dispensing a two-component composition, comprising: 
 a) a syringe body including, 
 i) a first elongated barrel having a proximate opening for receiving a first plunger rod and a first exit port for discharging a first component of the composition;  
 ii) a second elongated barrel having a proximate opening for receiving a second plunger rod and a second exit port for discharging a second component of the composition, the first and second barrels being arranged in parallel along the length of the syringe body;  
   b) a plunger rod assembly including, 
 i) a rearward stop plate,  
 ii) a first plunger rod having an outer threaded edge and an inner non-threaded edge, the first plunger rod having a forward-facing end portion for forcing the first component of the composition into the first exit port, and an opposing rear-facing end portion attached to the stop plate,  
 iii) a second plunger rod having an outer threaded edge and an inner non-threaded edge, the second plunger rod having a forward-facing end portion for forcing the second component of the composition into the second exit port, and an opposing rear-facing end portion attached to the stop plate, wherein the first and second plunger rods are arranged in parallel for joint movement within the first and second barrels respectively; and  
   c) a rotatable, threaded knob for connecting the plunger rod assembly to the syringe body, the threaded knob having a through-bore with a continuous internal thread for engaging the outer threaded edges of the first and second plunger rods so that as the knob is rotated, the plunger rods move together in a forward or rearward direction within the barrels.    
   
   
       2 . The dispensing syringe of  claim 1 , wherein the two component composition is a dental composition.  
   
   
       3 . The dispensing syringe of  claim 2 , wherein one component of the dental composition is a base paste and the second component is a catalyst paste.  
   
   
       4 . The dispensing syringe of  claim 2 , wherein the dental composition is a dental cement.  
   
   
       5 . The dispensing syringe of  claim 1 , wherein the first and second barrels have cylindrical structures.  
   
   
       6 . The dispensing syringe of  claim 1 , wherein the first and second exit ports are cylindrically-shaped.  
   
   
       7 . The dispensing syringe of  claim 1 , wherein the first and second exit ports are semi-circular shaped.  
   
   
       8 . The dispensing syringe of  claim 1 , wherein the inner edges of the first and second plunger rods each includes a radial fin, each radial fin extending along a length of the respective edge and radiating at an angle of about ninety degrees to the edge.  
   
   
       9 . The dispensing syringe of  claim 1 , wherein the first and second plunger rods each includes a piston attached to their forward-facing end portions for forcing the first and second components of the composition into the first and second exit ports respectively.  
   
   
       10 . The dispensing syringe of  claim 1 , wherein the syringe body further comprises a central supporting member having a pair of inner grooved segments for receiving the radial fins of the first and second plunger rods and guiding the plunger rods into the first and second barrels respectively.  
   
   
       11 . The dispensing syringe of  claim 1 , wherein the syringe body further comprises a ledge having a recessed area for receiving the rotatable threaded knob that connects the plunger rod assembly to the syringe body.  
   
   
       12 . The dispensing syringe of  claim 11 , wherein the ledge is circular-shaped and surrounds the first and second barrels of the syringe body.  
   
   
       13 . The dispensing syringe of  claim 11 , wherein the rotatable knob includes a locking flange so that the knob can be snap-fitted into the recessed area of the ledge on the syringe body.  
   
   
       14 . A dispensing syringe for dispensing a two-component composition, comprising: 
 a) a syringe body including, 
 i) a first elongated barrel having a proximate opening for receiving a first plunger rod and a first exit port for discharging a first component of the composition into a dispensing tip;  
 ii) a second elongated barrel having a proximate opening for receiving a second plunger rod and a second exit port for discharging a second component of the composition into the dispensing tip, the first and second barrels being arranged in parallel along the length of the syringe body;  
   b) a plunger rod assembly including, 
 i) a rearward stop plate,  
 ii) a first plunger rod having an outer threaded edge and an inner non-threaded edge, the first plunger rod having a forward-facing end portion for forcing the first component of the composition into the dispensing tip, and an opposing rear-facing end portion attached to the stop plate,  
 iii) a second plunger rod having an outer threaded edge and an inner non-threaded edge, the second plunger rod having a forward-facing end portion for forcing the second component of the composition into the dispensing tip, and an opposing rear-facing end portion attached to the stop plate, wherein the first and second plunger rods are arranged in parallel for joint movement within the first and second barrels respectively; and  
   c) a rotatable, threaded knob for connecting the plunger rod assembly to the syringe body, the threaded knob having a through-bore with a continuous internal thread for engaging the outer threaded edges of the first and second plunger rods so that as the knob is rotated, the plunger rods move together in a forward or rearward direction within the barrels.    d) a dispensing tip for receiving the first and second components of the composition from the first and second barrels and dispensing the composition to a desired area.    
   
   
       15 . The dispensing syringe of  claim 14 , wherein the dispensing tip includes a static mixer element.  
   
   
       16 . The dispensing syringe of  claim 14 , wherein the two component composition is a dental composition.  
   
   
       17 . The dispensing syringe of  claim 16 , wherein one component of the dental composition is a base paste and the second component is a catalyst paste.  
   
   
       18 . The dispensing syringe of  claim 16 , wherein the dental composition is a dental cement.  
   
   
       19 . A dispensing syringe for dispensing a multi-component composition, comprising: 
 a) a syringe body including multiple elongated barrels, each barrel having a proximate opening for receiving a plunger rod and an exit port for discharging a single component of the composition;    b) a plunger rod assembly including, 
 i) a rearward stop plate,  
 ii) multiple plunger rods, each plunger rod having an outer threaded edge and an inner non-threaded edge, and each plunger rod further having a forward-facing end portion for forcing a single component of the composition into an exit port, and an opposing rear-facing end portion attached to the stop plate, wherein the plunger rods are arranged for joint movement within the barrels; and  
   c) a rotatable, threaded knob for connecting the plunger rod assembly to the syringe body, the threaded knob having a through-bore with a continuous internal thread for engaging the outer threaded edges of the multiple plunger rods so that as the knob is rotated, the plunger rods move together in a forward or rearward direction within the barrels.    
   
   
       20 . The dispensing syringe of  claim 19 , wherein the syringe includes a dispensing tip.  
   
   
       21 . The dispensing syringe of  claim 20 , wherein the dispensing tip includes a static mixer element.  
   
   
       22 . The dispensing syringe of  claim 19 , wherein the multi-component composition is a dental composition.