The following pictures are meant to display possible physical characteristics of the present invention and are not to be taken in a limiting sense. It is understood that other embodiments may be utilized and that structural changes may be made without departing from the scope of the invention.

LIST OF REFERENCE NUMERALS 10 present invention 44 shutter plate sections 12 single use applicator 46 split edge of 42 14 attachment collar 48 displaceable valve 16 curvilinear nozzle 50 pressure disc 17 conduit of 16 52 stationary plate 18 valve member 54 snap-on nub 22 user 56 passage means cut-out 24 contaminated toothpaste 58 ball valve assembly 26 toothbrush 60 helical channel 28 dentifrice 62 ball valve 30 mouth of 22 64 point of egress of 17 32 tooth of 22 66 throughbore of 62 34 cap of 20 68 pivotal valve assembly 36 threads of 14 70 tube valve 38 threads of 20 72 valve plunger 40 shutter valve 74 applicator valve 42 shutter ring 76 valve stop

FIGURE 1 FIGURE 1 is an illustrative view of the prior art 20. Shown is an example of prior art comprising a deformable tube of toothpaste 20 that when utilized by multiple individuals can make the transmission of bacteria or disease from toothpaste 24 to toothbrush 26 a health risk to the user 22 which can be eliminated through use of disposable single use nozzles. The present invention provides a single-use nozzle having a collar with an outwardly extending tubular spout that decreases in diameter to a dispensing port. The nozzle has a curvilinear shape whereby any mateable container of a substance requiring oral cavity application can use the curvilinear nozzle to deliver said substance to a desired location in the desired predetermined amount. FIGURE 2 FIGURE 2 is a perspective view of the periodontal/oral cross contamination prevention system 10 of the present invention in use. Shown is the single use applicator 12 attached to a toothpaste tube 20 via a threaded attachment collar 14 to provide for a single use application of a dental substance either to a desired location within an oral cavity or to prevent direct contact between the toothpaste dispenser nozzle 16 and the user's toothbrush. The nozzle 16 includes a central throughbore forming a conduit 17 having a nozzle valve 18 disposed therein that as the dental substance, in this case illustrated as toothpaste, is dispensed by pressure applied to the pliable tube 20 acts upon the valve 18 to block the throughbore 17 after a predetermined amount of dental substance has been dispensed. FIGURE 3 FIGURE 3 is a perspective view of the periodontal/oral cross contamination prevention system of the present invention 10 in use. Shown is the single use applicator 12 in use with a toothpaste tube 20. The curvilinear form of the nozzle 16 allows for direct oral application of a dental dentifrice 28 to precise locations in one's mouth 30 such as exact location of gum line for sensitive teeth 32 or for placement of dentifrice 28 between or under orthodontic appliance. FIGURE 4 FIGURE 4 is an illustrative view of the periodontal/oral cross contamination prevention system of the present invention 10 during installation. Shown is the single-use applicator 12 being installed to a typical dispensing end of a dental substance tube 20 much like a cap 34. The nozzle collar 14 has threads 36 that screw onto mating threads 38 on the tube 20 which normally accommodate the cap 34. Additionally the present invention 10 provides a curved and extended nozzle 16 with a central conduit 17 to aid the user in more precise application of a substance. Furthermore, the conduit 17 projects into the collar 14 thereby penetrating into the tube 20 upon threading to assure the introduction of fresh dentifrice therein. FIGURE 5 FIGURE 5 is a stepwise view of the single-use nozzle 12 having a shutter-like valve 40. Depicted is the single use applicator 12 of the present invention 10 that provides a collar 14 for engaging a pliable toothpaste tube 20. The first step of usage requires screwing the applicator 12 onto the tube 20. The applicator 12 has a nozzle 16 with a conduit 17 curvilinearly extending in a diametrically decreasing fashion with an interiorly movable valve member 18 whereby the applicator 12 is single use as a result it advancing down the conduit 17 allowing toothpaste 24 to be dispensed until the valve 18 moves to its blocking position whereby no further toothpaste 28 can be dispensed. Having no means to retract the valve 18 results in a single use applicator 12. As illustrated, the movable valve 18 is a shutter valve 40 comprising a resilient shutter-like cylindrical ring 42 with a split edge 46 on the side and internal plate sections 44 that are spaced apart when the split edges 46 of the shutter ring 42 are separated and abut one another when the split edges 42 meet thereby effectively forming a barrier restricting any further dispensing of the toothpaste 28. The shutter valve 40 advances down the conduit 17 under pressure from the toothpaste 28 allowing toothpaste 28 to pass therethrough. The shutter valve 40 closes incrementally as it travels down the conduit 17 due to the decreasing diameter of the conduit 17 until the shutter valve 40 closes whereby no further toothpaste 28 will be dispensed and with no means for retracting the valve creates the single-use valve. FIGURE 5A & 5B FIGURE 5A and 5B shown is an illustration of the single-use nozzle with an advancing shutter valve and a sectional view through said valve. Depicted is the single use applicator 12 of the present invention 10 that provides a collar 14 for engaging a pliable toothpaste tube 20. The first step of usage requires screwing the applicator 12 onto the tube 20. The applicator 12 has a nozzle 16 with a conduit 17 curvilinearly extending in a diametrically decreasing fashion with an interiorly movable valve member 18 whereby the applicator 12 is single use as a result it advancing down the conduit 17 allowing toothpaste 24 to be dispensed until the valve 18 moves to its blocking position whereby no further toothpaste can be dispensed. Having no means to retract the valve 18 results in a single use applicator 12. As illustrated, the movable valve 18 is a shutter valve 40 comprising a resilient shutter-like cylindrical ring 42 with a split edge 46 on the side and internal plate sections 44 that are spaced apart when the split edges 46 of the shutter ring 42 are separated and abut one another when the split edges 42 meet thereby effectively forming a barrier restricting any further dispensing of the toothpaste. The shutter valve 40 advances down the conduit 17 under pressure from the toothpaste 28 once the tube 20 is squeezed by the user thus allowing toothpaste 28 to pass therethrough. The shutter valve 40 closes incrementally as it travels down the conduit 17 due to the decreasing diameter of the conduit 17 until the shutter valve 40 closes whereby no further toothpaste will be dispensed and with no means for retracting the valve creates the single-use applicator 12. FIGURE 6 FIGURE 6 is a stepwise view of the single-use applicator 12 of the present invention 10 having a displaceable valve 48. The single use applicator 10 provides a collar 14 for engaging a pliable tube 20 of toothpaste 28 with a nozzle 16 curvilinearly projecting therefrom. A conduit 17 is disposed within said nozzle 16 to provide passage of toothpaste 28 from the tube 20 to the desired point of delivery. Shown is the displacable valve 48 comprising a movable pressure disc 50 disposed within the collar 14 proximal to the point of egress of the dispensing tube 20 and a spaced apart stationary plate 52 disposed within said collar 14 proximal the conduit 17. The pressure disc 50 and the stationary plate 52 are offset to encourage passage of toothpaste 28 therethrough while they are in a spaced apart relation. The introduction of toothpaste 28 therethrough applies a bias to the pressure disc 50 thereby urging it towards the stationary plate 52 as the toothpaste 28 is being delivered through the conduit 17. Engagement of the pressure disc 50 with the stationary plate 52 prohibits further egress of the toothpaste 28. FIGURE 6A FIGURE 6A is an enlarged view of the displaceable valve 48 of the present invention 10. Depicted is the pressure disc 50 moving to engage the stationary plate 52 under pressure from the toothpaste allowing toothpaste to pass the valve 48 through cut-out passage means 56 in the disc 50 and the plate 52 and proceed through the conduit 17 of the nozzle 16 until the pressure disc 50 engages the stationary plate 52 whereby no further toothpaste will be dispensed and with no means for retracting, the displaceable valve 48 creates the single-use applicator 12. The attachment collar 14 further includes a snap-on nub 54 to enable the user to simply snap the applicator 12 on and of the dispensing tube 20 without threading. FIGURE 7 FIGURE 7 is a stepwise view of the single-use applicator 12 of the present invention 10 having a ball valve assembly 58. Depicted is the single use applicator 12 that provides collar 14 for engaging a pliable toothpaste tube 20 with a nozzle 16 curvilinearly projectinging therefrom. A diametrically decreasing conduit 17 extends through the nozzle 16 with a helical channel 60 therein. A ball valve 62 is positioned within the conduit 17 proximal the collar 14 when in the open static position. The ball valve 62 has a central throughbore 66 passing therethrough The introduction of toothpaste 28 into the conduit 17 urges the ball valve 64 forward along the helical channel 60 while the throughbore 66 permits toothpaste 28 to flow therethrough for delivery at the point of egress 64 of said conduit 17. The flow of toothpaste 28 is terminated upon the ball valve 62 reaching the distal end of said helical channel 60 wherein the throughbore 66 is in transverse relation to the point of egress 64. The diameter of the point of egress 64 is less than that of the ball valve 62 thereby prohibiting further travel thereof. FIGURE 7A FIGURE 7A is an illustration of the single-use applicator 12 of the present invention 10 with an advancing ball valve 62. As illustrated, the single use applicator 12 has a nozzle 16 that extends curvilinearly from the nozzle mounting collar 14. The nozzle 16 has an integral conduit 17 with and interiorly movable ball valve 62 whereby the applicator 12 is single use as a result of the ball valve 62 advancing down the helical channel 60 of the conduit 17 allowing toothpaste to be dispensed until the ball valve 62 moves to its blocking position whereby no further toothpaste can be dispensed. Depicted is the ball valve 62 having a throughbore 66 that advances down the helical channel 60 under pressure from the toothpaste allowing toothpaste to therethrough until the throughbore 66 rotates transversely out of alignment with the point of egress 64. FIGURE 8 FIGURE 8 is a stepwise view of the single-use applicator 12 of the present invention 10 having a pivotal valve assembly 68. Depicted is the single use applicator 12 having an additional element wherein the pliable toothpaste tube 20 has an integral tube valve 70 so that no toothpaste will be dispensed without employing the single-use applicator 12 with the pliable tube 20. The applicator 12 provides a collar 14 for engaging a pliable tube of toothpaste 20 and a nozzle 16 projects curvilinearly therefrom. A conduit 17 extends longitudinally through the nozzle 16 for delivering a pre-determined amount of toothpaste 28 to the distal end thereof. The proximal end of the conduit 17 projects beyond the edge of the collar 14 for entry into the dispensing tube 20 when engaged therewith thereby forming a valve plunger 72. A pivotal tube valve 70 is employed within the tube 20 and refuses egress of any toothpaste 28 until the valve plunger 72 drives it back to allow entrance into the conduit. A pivoting applicator valve 74 is disposed within the collar 14 and is driven towards the conduit 17 entrance as the toothpaste 28 travels through the conduit 17. Once the applicator valve 74 engages a valve stop 76 disposed at the conduit 17 entrance the flow of any further of toothpaste 28 therethrough is prohibited. The tube valve 70 within the dispensing tube 20 assures that no toothpaste 28 will be dispensed therefrom bypassing the usage of a new sanitized single use applicator. FIGURE 8A FIGURE 8A is an illustration of the single-use applicator 12 with a pivotal valve assembly 68. As illustrated, the valve plunger 72 extends from the nozzle mounting collar 14 into a tube 20 spout having an interior pivoting tube valve 70. The curvilinear spout is single use as a result of the pivot valve assembly 68 that allows toothpaste to be dispensed until the applicator pivot valve 74 pivots to its blocking position at the valve stop 76 whereby no further toothpaste can be dispensed. Depicted is the applicator valve 74 pivoting under pressure from the toothpaste allowing toothpaste to move past the valve as it pivots to closure so that no further toothpaste will be dispensed until replaced with a new, sanitized applicator 12.