a therapeutic gum irrigator for home use is described below . the irrigator allows a user to perform periodontal irrigation between visits to a treating professional . the irrigator allows for subgingival irrigation with a fluid , including a chemotherapeutic / bactericidal fluid , a fluoride - containing fluid , and / or water . depending on the type of fluid used , the process of irrigation helps to cleanse periodontal pockets through mechanical disruption of a plaque biofilm within the cavity and / or bactericidal effect of the irrigating fluid . moreover , the fluid may contain an anti - inflammatory and / or analgesic component to help relieve symptoms of periodontitis . the fluoride fluid component may help to desensitize root surfaces and to arrest or prevent root caries . the therapeutic gum irrigator is designed to facilitate ergonomic irrigation of a user &# 39 ; s periodontal pockets , but may also be used by a lay person or treating professional to irrigate periodontal pockets of a patient . in this context , treating professionals include , but are not limited to , oral hygienists , dentists , periodontists , and / or oral surgeons . as seen in fig1 and 2 , a therapeutic gum irrigator 10 has a housing 12 connected to a neck 14 . the neck 14 includes a proximal end 16 that connects the neck to the housing 12 , and a distal end 18 . a cannula 20 for subgingival application of a fluid to a user &# 39 ; s periodontal pockets depends from the neck distal end 18 . the housing 12 is shaped such that a user can easily and comfortably manipulate the therapeutic gum irrigator 10 . further , the housing is removably connected to and preferably at least partially surrounds a generally cylindrical reservoir 22 and a pump 24 . the housing 12 defines a fill opening 26 ( fig3 ) that allows a user to fill the reservoir 22 without need to remove the reservoir . a cover 28 is hingedly attached to the housing 12 and covers the fill opening 26 . when closed , the cover 28 and housing 12 preferably form a substantially water - tight barrier to help prevent liquid from escaping the reservoir 22 . the cover 28 is preferably attached to the housing 12 via a biased hinge , such as a biased living hinge or a spring - biased barrel hinge , such that the cover 28 is biased towards a closed position . however , artisans will recognize that additional biased and non - biased hinge options are within the scope of the invention . the reservoir 22 is preferably formed from a relatively light weight , resilient material , such as plastic or acrylic , and is preferably transparent or translucent so a user can easily monitor the fluid in the reservoir . as shown in fig1 , the reservoir 22 generally defines a reservoir axis r , which passes through the center of the reservoir . the neck 14 is generally j - shaped , having a straight portion 30 adjacent to the proximal end 16 , and an arcuate portion 32 adjacent to the distal end 18 . preferably , the neck 14 is formed from a relatively soft , resilient biocompatible acrylic , plastic , or rubber material , but those of skill in the art will recognize that any known biocompatible material may be used to form the neck . the neck 14 serves to connect the cannula 20 to the housing 12 . as shown in fig1 , the straight portion 30 defines a neck axis n passing through a center of the straight portion . the neck axis n is angled obliquely relative to the reservoir axis r . this helps to ergonomically position the cannula 20 for proper subgingival insertion . preferably , the neck 14 is connected to the housing 12 by a rotatable coupler 34 . the coupler 34 is generally coaxial with the straight portion 30 of the neck 14 , and allows the neck to rotate about the neck axis n . this rotation may be a smooth rotation about the axis n to allow for arbitrary positioning of the neck , or there may be one or more predefined positions at which the rotation is halted , for example by detents in the rotational coupling or other known systems . the rotational coupler 34 allows for positioning of the neck 14 and cannula 20 to help allow easy , ergonomic access to all four quadrants of the user &# 39 ; s mouth without need to rotate the housing 12 . the cannula 20 is a hollow tube formed from a resilient biocompatible material , such as metal , plastic , or acrylic . the cannula 20 is preferably generally cylindrical , though one of skill in the art will recognize that other shapes are possible without departing from the scope of the invention . the cannula 20 depends from the arcuate portion 32 of the neck 14 , and defines a cannula axis c passing through the center of the cannula . the cannula axis c is oriented such that the axis c is not parallel with the reservoir axis r or the neck axis n . preferably , the axes c and n are approximately orthogonal , though all orientations of the axis c that are non - parallel with axes n and r are contemplated . accordingly , an angle α is formed between the reservoir axis r and neck axis n . similarly , an angle β is formed between the neck axis n and the cannula axis c , and an angle γ is formed between the cannula axis c and the reservoir axis r . preferably , β is approximately equal to 90 °, and α is approximately equal to 90 − γ . the angles α , β , and γ are selected to help ensure that relatively difficult to reach portions of the mouth , such as distal areas of the back molars , are accessible . accordingly , those of skill in the art will recognize that other angles may be selected without departing from the scope of the invention . the cannula 20 is sized for subgingival insertion , and to accurately direct fluid to an area selected by the user , such as a periodontal pocket . in some embodiments , the cannula may direct the fluid in a single direction . other embodiments include side ports on the cannula , allowing for a more dispersed flow of the fluid . turning now to fig3 , a cross - sectional view of the therapeutic gum irrigator 10 is shown . the pump 24 is preferably a single - acting , single - cylinder positive displacement reciprocating pump as shown in fig2 ; however , artisans will recognize that other pumps may be used without departing from the scope of the invention . the pump 24 is disposed such that an intake siphon 36 extends into the reservoir 22 . a pump outlet 38 is in fluid communication with the cannula 20 . the intake siphon 36 includes a one - way valve allowing fluid to flow from the reservoir 22 to the pump 24 , but preventing fluid flow in the opposite direction . similarly , the outlet 38 includes a one - way valve allowing fluid to flow from the pump 24 to the cannula 20 , but preventing opposite - direction flow . the pump 24 further includes a displacing element such as piston 40 movable between first and second positions , and a biasing element such as biasing spring 42 biasing the piston to the first position . a mechanical actuator lever 44 is hingedly connected to the housing 12 and positioned to mechanically move the piston 40 to the second position . in operation , a user applies force to the lever 44 sufficient to overcome the biasing force of the biasing spring 42 . this user - applied force causes piston 40 to move from the first position to the second position . as the piston 40 moves , it displaces fluid in the pump , causing the fluid to be flow through the pump outlet 38 to be expelled at the cannula 20 . once the user releases the lever 44 , the biasing spring 42 causes the piston 40 to return to the first position , inducing fluid flow from the reservoir 22 into the pump 24 via intake siphon 36 . those of skill in the art will recognize that the volume of fluid displaced by each actuation of the pump 24 is proportional to both the cross - sectional area of the piston and the piston travel distance . preferably , area and travel distance are selected so that the volume of displaced fluid is within a range of about 1 - 4 ml . however , larger and smaller volumes are contemplated . additionally , a pressure at which fluid is expelled from the cannula 20 is a function of the selected fluid volume and a cross - sectional area of the cannula . thus , it is preferable that the fluid volume and cannula cross - sectional area are chosen so that the pressure produced is sufficient to irrigate the pockets without causing damage to the surrounding tissue or causing undue discomfort to the user / patient . the therapeutic gum irrigator 10 can include a light source 46 positioned to illuminate at least an area surrounding the cannula 20 . the light source 46 may include one or more light emitting diodes , fluorescent bulbs and / or incandescent bulbs . electrically coupled to the light source 46 is a power source 48 such as a battery , and an operating switch 50 . the operating switch 50 is disposed in a position to open or close a circuit including the light source and battery , thereby enabling or disabling flow of electricity from the power source 44 to the light source 46 . the switch 50 is preferably a known electrical switch such as a biased normally - open switch or a toggle switch , but those of skill in the art will recognize that other switches may be used without departing from the scope of the invention . the light source 46 is arranged near the rotatable coupler 34 . preferably , at least portions of the neck 14 and cannula 20 are formed from a transparent or translucent material to allow for better illumination . turning now to fig4 , 5 a , and 5 b , the therapeutic gum irrigator 10 preferably further includes a filling cup 52 to aid a user in filling the therapeutic gum irrigator 10 . the cup 52 is sized such that a volume of the cup is substantially similar to a volume of the reservoir 22 . preferably , the cup 52 may include gradations indicating volume , and is preferably formed from a transparent or translucent material to easily allow a user to determine a volume of fluid contained in the cup . the cup 52 further includes a pour spout 54 having a size and shape selected to aid a user in transferring fluid from the cup to the reservoir 22 via the fill opening 26 formed in the housing 12 . alternatively , the reservoir 22 may be detached from the housing 12 and filled directly , with or without use of the fill cup 52 . as shown in fig5 a and 5b , the cup 52 can have a tear - drop shape , with a relatively wide portion and a tapered spout 54 . this allows the cup to rest comfortably in a user &# 39 ; s hand , while adequately directing liquid . a base 56 of the fill cup 52 is sized to accommodate a base of the reservoir 22 when the fill cup is not being used to fill the reservoir . optionally , the base 56 may be sized to closely fit at least a portion of the reservoir 22 , such that the therapeutic gum irrigator 10 is removably engaged with the cup 52 by a frictional fit . turning to fig6 , the housing 12 surrounding at least a portion of the therapeutic gum irrigator 10 may include a textured coating 58 to aid the user in gripping the irrigator . the coating 58 is preferably formed from a soft - touch plastic or rubber , though any material suitable for forming the housing 12 could also be used to form the coating . while the principles of the invention have been described above in connection with specific apparatus and applications , it is to be understood that this description is made only by way of example and not as a limitation on the scope of the invention .