Pulsed radiation source adapted for curing dental restoratives
AssigneeMinnesota Mining and Manufacturing Company
InventorWilliam H. Long
Life of this patent
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Abstract
An apparatus for providing controlled flashes of radiation, including a handpiece within which is mounted a gaseous discharge tube and a light pipe for conducting the radiation, enabling it to be directed into an oral cavity to effect in situ curing of radiation polymerizable resins used as dental restoratives. The apparatus further includes electrical circuitry for producing a train of a fixed number of relatively constant intensity flashes each time a switch is closed, and for disabling the apparatus after the flash tube has been discharged a predetermined number of times, thereby preventing unsatisfactory performance resulting from a fall-off in intensity due to aging of the tube.
Claims15
Apparatus adapted for hardening radiation polymerizable compositions used in making dental restorations, said apparatus comprising
- a housing adapted to be hand-held proximate an oral cavity.
- a gaseous discharge tube mounted within the housing for providing a source of radiation,
- a radiation transmissive rod for coupling radiation from said tube and through the housing, said rod being adapted for insertion into an oral cavity to direct said radiation toward a said composition, and
- a power supply including charge storage means for intermittent energization of said tube,
- characterized by
- said power supply including
- (i) control means for applying a predetermined potential to said charge storage means during quiescent periods during which said discharge tube is unenergized,
- (ii) hold-off means coupled to said control means for preventing said application of potential to said charge storage means for at least a predetermined duration following each energization of said discharge tube,
- (iii) pulse control means for generating a train of a predetermined number of electrical pulses within a given interval of time, and for coupling said pulse train to trigger means associated with said discharge tube in response to an initiate signal to cause said discharge tube to be discharged a like number of times, each flash having associated therewith a substantially constant energy as controlled by said predetermined potential from said control means, and
- (iv) means for providing an indication when the intensity of successive flashes produced upon the discharge of said substantially constant amount of energy into the tube decreases to a predetermined minimum level, said indication providing means comprising counter means responsive to said pulse control means for representing the number of pulses coupled to said trigger means and for providing an indication when said number exceeds a predetermined value, such that the desirability of replacing said discharge tube is indicated prior to the onset of unsatisfactory curing of said compositions due to a fall-off in said intensity.
Apparatus adapted for hardening radiation polymerizable compositions used in making dental restorations, said apparatus comprising
- (a) a handpiece adapted to be hand-held proximate an oral cavity, including
- an exterior, UV radiation impermeable housing,
- a gaseous discharge tube mounted within said housing for providing a source of radiation, and
- a radiation transmissive rod optically coupled to said tube for conducting radiation from the tube and through the housing, said rod being adapted for insertion into an oral cavity to direct said radiation toward a said composition, and
- (b) a power supply for intermittent energization of said tube,
- characterized by
- said rod including a light pipe having a lower index cladding layer surrounding a higher index core,
- said handpiece including means for receiving an end of said rod into said housing such that said end is butted against a first surface of said tube, reflector means positioned within said housing having a generally concave, reflecting surface for receiving said tube therein such that said first surface of said tube may be butted against said received end of said rod and for redirecting radiation emitted from said tube toward said end of said rod, and mechanical bias means for maintaining said rod, tube, and reflector means in a butted-together relationship in intimate optical contact so as to maximum the collection of emitted radiation within the light pipe and thence toward a said composition.
Dependencies are inferred from the claim text.