Patent ID: 7806689

Claim:
A disposable dental instrument capable of discharging tooth cleaning fluid therefrom, comprising: a housing having a central bore terminating in a head portion with a wheel room formed at said head portion in said housing and wherein a drain hole is formed to serve as a passageway between said wheel room and a tube room formed in said housing having inside wall surfaces with an insertion groove formed at a given depth along the top of said inside wall surfaces; a tube composed of a flexible material mounted in said tube room and having a tube inlet that fits snuggly into said drain hole in said housing and also having flexible sidewalls that are sealed such that a planar surface is formed; a roller having protrusions on opposite side surfaces that fit within said inside wall surfaces of said tube room; a lid having a roller guide formed in one direction thereof being coupled therealong with said insertion groove after said tube and said roller are mounted in said tube room in such a manner as for said roller to be pushed with one finger along said roller guide to apply compressive force to said tube; a wheel mounted in said wheel room and having a bottom face, a wheel drain hole, and a wheel gear; a drive shaft centered and mounted for rotation within said central bore and having a shaft gear that is rotatably mounted with said wheel gear; a prophy cup having a lower portion, a middle portion, a prophy cup drain hole formed in said prophy cup to pass through said middle portion for receiving said tooth cleaning fluid therethrough, a top periphery with a ring-shaped close contact face formed along said top periphery, an inner periphery of said ring-shaped close contact face, an elastic close contact groove formed along said inner periphery of said ring-shaped close contact face, and wherein said ring-shaped close contact face and said elastic close contact groove are adapted for close contact with said head portion of said housing and with said bottom face of said wheel; and a rod that is long, thin, and very flexible and that said rod seals said tube inlet of said tube and that said rod is inserted into said dental instrument through said prophy cup drain hole, through said wheel drain hole, through said drain hole in said housing, and into said inlet of said tube in such a manner as to unseal said inlet of said tube when said rod is pulled out of said dental instrument.