WO2006039509A1

WO2006039509A1 - Sterilizer for and method for sterilizing dental handpieces

Info

Publication number: WO2006039509A1
Application number: PCT/US2005/035222
Authority: WO
Inventors: Eugene J. Novak; Amit Patel; Kevin Rogers Brennan
Original assignee: Dentsply International Inc.
Priority date: 2004-09-30
Filing date: 2005-09-29
Publication date: 2006-04-13
Also published as: EP1796740A1; CA2581900A1; JP2008514375A

Abstract

A sterilizer for a dental handpiece is provided. The sterilizer provides equalized distribution of steam to a plurality of handpieces, assured minimum lubrication delivery and pressurized exhaust handpiece maintenance adapters. There is also provided a swivel adapter for a fixed-back handpiece and a detergent tablet for the cleaning chamber. There is also provided oil and evaporable solvent solution for lubrication purposes; reservoir inlet specific pour spout; SCBI and steam strip holder; a water reservoir flush routine; and, a forced chamber drain cycle.

Description

STERILIZER FOR AND METHOD FOR STERILIZING DENTAL

HANDPIECES

Related Applications

[0001] This application is a U.S. non-provisional application which claims the priority benefit from U.S. Provisional Application No. 60/614,820 filed September 30, 2004.

Technical Field

[0002] The present invention generally relates to an improved sterilizer for dental handpieces.

Background of the Invention

[0003] Sterilizers for dental handpieces are known. For example, US Pat. Nos. 5,520,892 and 5,348,711 disclose sterilizers for dental handpieces and are hereby incorporated by reference. A commercially available dental sterilizer over which the present invention is an improvement is the DAC-2000 available from Nitram Dental. [0004] Uniform temperature of an autoclave chamber during sterilization is required to meet industry standards such as AAMI ST-55. This requirement is to insure that the autoclave will not have cold-zones that compromise sterilization efficacy or hot-zones that can cause damage to the articles being sterilized.

[0005] The original DAC-2000 design provided by Nitram Dental introduced steam, introduced into the chamber in an undistributed fashion, which resulted in uneven hea-ting requiring long chamber stabilization periods. Specifically, the Nitram design did not evenly distribute steam to all four entry ports in the autoclave chamber due to different pressure drops along the four different plumbing paths which consisted of several lengths of tubing and various fittings and adapters.

[0006] The general concept of a distribution manifold with equal path lengths and equal pressure drops is well known in engineering. No prior art patents related to steam distribution in an autoclave are known at this time. No other instances of autoclaves with such an equalizing manifold are known to the inventors. In the most narrow case of a dental handpiece autoclave with a vertical chamber and bottom entry steam ports the prior art is the Nitram design which does not have the inventive feature of equal steam distribution.

[0007] Dental handpiece manufacturers recommend that a measured amount of lubricant be delivered to the dental handpiece after each use to achieve full life of the handpiece. Our studies show that lubrication during reprocessing removes debris from the handpiece bearings and reduces friction during subsequent operation. Failure to flush the handpiece with sufficient new lubricant allows destructive accumulation of debris and a decline in lubrication, leading to premature failure of the handpiece bearings and other components.

[0008] Further, automation of lubricant delivery is advantageous during reprocessing, since it can assure proper and consistent lubrication (i.e. eliminating human factors), and provide labor reduction by allowing the lubrication of multiple handpieces in one step. [0009] hi the original DAC-2000 design provided by Nitram Dental, oil was pumped to the six handpieces through a distribution manifold which favored the path of least resistance so that more restrictive handpieces were not adequately lubricated. In the worst case, a handpiece with high flow resistance might receive no oil at all while other handpieces processed at the same time were over-lubricated.

[0010] The general concept of a distribution manifolds with equal path lengths and equal pressure drops is well known in engineering. No prior art patents related to oil distribution in dental handpiece lubricating system are known at this time. No other instances of handpiece lubricating systems with the inventive manifold and method are known to the author. The original Nitram design did not have a manifold with equal channels, nor did it effectively use a two-step process to supply an assured minimum volume of lubricant to each handpieces. Adec and W&H sell the W&H Assistina, which lubricates only a single handpiece, using air pressure to drive liquid oil through the handpiece for a fixed duration. The Assistina does not have an oil pump, or manifold. [0011] The KaVo QuatroCare lubricates one to four handpieces simultaneously using a single aerosol can filled with lubricant and a propane/butane propellant. The QuatroCare has neither an oil pump, manifold nor a two-step method. The NSK CareThree lubricates one to three handpieces simultaneously using air pressure to drive a liquid mixture of oil and alcohol through the handpiece for a fixed duration. The CareThree uses neither an oil pump nor a two-step method.

[0012] Providing a measured amount of new lubrication to a dental handpiece at each reprocessing cycle is required by most handpiece constructions to achieve their full useful life. Lubrication during reprocessing has been shown by internal studies to both remove operational debris and provide friction abatement for a headpiece's moving components. Failure to flush the handpiece with sufficient new lubricant allows for a destructive accumulation of debris and a decline in friction abatement, leading to premature failure of the handpiece. Further, excessive lubricant may become pooled within the handpiece and later be expelled onto the patient's teeth during use, compromising restorative bonding. [0013] The original Nitram design did not effectively remove excessive lubricant from handpieces. Oil delivered to the handpiece was pressed up into the exhaust channel and left to pool. Adapter designs constructed to block the exhaust channel also allowed lubricant to pool in the exhaust channels due to the compressibility of the trapped air. [0014] Dental handpiece reprocessing systems require a positive connection to the lumens of each handpiece via an adapter to deliver lubricant and/or steam to each handpiece. The adapter must also securely hold the handpiece within the reprocessing device.

[0015] Adapter design is relatively simple for dental handpieces, attachments, or motors having some form of quick-connect coupling. The original DAC-2000 design provided by Nitram Dental had only adapters for handpieces with quick-connect couplers. However, handpieces with so-called "fixed back-ends" have a threaded connection which ordinarily requires the user to laboriously turn and tightened a threaded ring to affix the handpiece to a hose or adapter. The various types of fixed back-end connections are commonly defined by ISO standard 9168. [0016] A further problem is that different handpieces or motors may need to be oriented in different direction to fit in the chamber of the reprocessing device. Ordinarily, an adapter for "fixed back-ends" handpieces will only allow a handpiece to be mounted in one orientation determined by the holes in the adapter and corresponding tubes on the back-end of the handpiece. The original design provided by Nitram Dental did hot have any provision for altering the orientation of a fixed back-end handpiece in the chamber. [0017] There have been devices for attaching to, and holding, dental handpieces with fixed back-ends:

• Dental hoses. These lack the spring loaded feature of the inventive device. Some hoses may have a rotation feature built into the hose end.

• The adapter in the W&H Assistina handpiece lubrication device sold in the US by Adec. This adapter is similar to the original Nitram design and lacks the spring loaded & swivel features of the inventive device.

• The adapter in the KaVo QuatroCare handpiece lubrication device. [0018] The original design by Nitram Dental, which lacked both the spring loaded and swivel features of the inventive design.

[0019] Lubrication of dental handpieces after each use is necessary to achieve full useful life. This lubrication step, whether manual or automated, can result in oil on the exterior of the dental handpiece. This eternal oil is obviously undesirable to the dentist. [0020] Handpieces processed in the original DAC-2000 rinse-lube-autoclave device supplied by Nitram Dental had excessive eternal oil after processing. Attempts to vary the timing of a post-lubrication rinse step did not solve the problem. [0021] The use of detergents to remove oil and otherwise clean articles is obviously well known, including in the dental and medial field. Manually cleaning the exterior of dental handpieces with water and detergent (or disinfectants) is routine practice. Ultrasonic cleaners, filled with water and detergent, are often used to clean dental handpieces. There are several devices similar to home dishwashing machines sold for cleaning dental instruments with water and detergents, though none of these washers has been approved for use on dental handpieces. The supplier of the inventive tablet, Alconox, has previously made effervescent detergent tablets for other applications. However, there is no known prior instance, either in practice or by patent, of a detergent tablet used in an automated handpiece reprocessing device. [0022] Dental handpiece manufacturers recommend that a measured amount of lubricant be delivered to the dental handpiece after each us to achieve full life of the handpiece. Our studies show that lubrication during reprocessing removes debris from the handpiece bearings and reduces friction during subsequent operation. Failure to flush the handpiece with sufficient new lubricant allows destructive accumulation of debris and a decline in lubrication, leading to premature failure of the handpiece bearings and other components.

[0023] Further, automation of lubricant delivery is advantageous during reprocessing, since it can assure proper and consistent lubrication (i.e. eliminating human factors), and provide labor reduction by allowing the lubrication of multiple handpieces in one step. [0024] hi the original DAC-2000 design provided by Nitram Dental, oil was pumped from a reservoir to the six handpieces and subsequent steps attempted to remove excess oil with air and water. The oil served two functions: flushing and lubrication. If the amount of oil was sufficient for proper flushing of debris, oil would accumulate on and in the handpieces and would not be expelled during the automatic reprocessing cycle. Residual oil on external surfaces was objectionable to customers, and excess internal oil could later be expelled onto trie patient's teeth during use. [0025] Midwest Plus™ liquid oil is one of the constituents of the inventive mixture. [0026] Several handpiece manufacturers (eg KaVo, Midwest, BienAir) sell aerosol spray cleaner/lubricants which consist of oil with a propane/butane propellant which also serves as a cleaning solvent and diluent for the oil.

[0027] NSK sells a mixture of oil and alcohol as a cleaner/lubricant in their CareThree automated handpiece lubricator.

[0028] In Europe only, KaVo sells a liquid mixture of oil and solvent for manual handpiece cleaning and lubrication.

[0029] There is no known commercial instance of a oil/solvent mixture used in a device which rinses, lubricates and sterilizes dental handpieces.

[0030] In the DAC-2000 lube-rinse-sterilizer design supplied by Nitram Dental, users often mistakenly fill the water reservoir with oil, which requires significant service to correct.

[0031] There are numerous instances of liquid filled bottles with "push to dispense" nozzles. There are very likely commercial instances and patent prior art related to dispensing bottles with tips configured to be compatible with the proper fill port.

[0032] The Harvey ChemiClave solution uses a dispensing nozzle, however no commercial or patent prior art is known to the author for such a filling system used in an autoclave, or in a dental handpiece rinse-lube-sterilize device.

[0033] To meet current industry regulations and practices an autoclave must provide means to perform periodic validation of sterilization efficacy of a representative full load at its point of use, as well as provide independent verification of a completed cycle. The original DAC-2000 design by Nitram Dental did not include any means to do this.

Specifically, what was needed was a means to hold steam strips and SCBIs (self- contained biological indicators) in the sterilizer chamber during a full rinse-lube-sterilize cycle. The means needed to be convenient for the user, accommodate several commercially available types of strip and SCBI, not distort the results of the indicators, and allow the chamber to be fully loaded.

[0034] The general concept of spring clips of similar physical construction is well known. The author is not aware of any commercial or patent prior art related to such a clip or holding means in an autoclave chamber. With regard to the Nitram DAC-2000, there was no provision for mounting of indicators.

[0035] To meet current industry regulations and practices an autoclave must provide means to be easily flushed and cleaned. The original DAC-2000 design supplied by

Nitram Dental did not have this capability, but required a laborious manual process.

Water tanks are emptied by siphoning out the tank or other external means.

[0036] Providing lubrication at each reprocessing cycle is required by most handpiece constructions to achieve their full useful life. Excess internal lubrication must be mitigated or it will be expelled onto the patient's teeth during use, compromising restorative bonding. Handpiece manufacturers' reprocessing instructions typically recommend the handpiece be blown out with compressed air after lubrication to remove excess internal oil and then wiped to remove any resulting external oil prior to sterilization.

[0037] hi the lube-rinse-sterilizer DAC-2000 originally designed by Nitram Dental, expelling of internal oil with compressed air within the device's chamber redeposited the oil on the external surfaces of the handpieces during subsequent water rinsing. In. particular, the expelled oil remained in the bottom of the chamber where it mixed with residual water from the previous rinse steps. During rinsing, water entering the four ports at the bottom of the chamber sprayed the residual oil/water mixture over all handpiece exteriors.

[0038] The notion of using compressed air to drain a chamber is likely used in some autoclaves and probably in other similar devices as well. There is no known commercial or patent prior art describing this particular inventive modification to a dental handpiece rinse-lube-sterilize device.

Brief Description of the Drawings

[0039] Figure 1 is a sectional and partially schematic, elevational view of a dental handpiece sterilizing appliance according to the invention.

[0040] Figure 2 is a schematic view of a prior art steam flow path.

[0041] Figure 3 is a schematic view of a steam flow path according to the present invention.

[0042] Figure 4 is a top view of a manifold used to affect the flow path of Figure 3.

[0043] Figure 5 is a side sectional view of one portion of the manifold of Figure 4, taken along line A-A of Figure 4.

[0044] Figure 6 is another side sectional view of one portion of the manifold of Figure

4, taken along line C-C of Figure 4.

[0045] Figure 7 is a is another side sectional view of one portion of the manifold of

Figure 4, taken along line B-B of Figure 4.

[0046] Figure 8 is a perspective view of the manifold of Figure 4.

[0047] Figure 9 is another view of a sterilizing appliance as in Figure 1. [0048] Figure 10 is a top view of an oil distribution manifold useful with the appliance of Figure 9.

[0049] Figure 11 is another view of a sterilizing appliance as in Figure 1.

[0050] Figure 12 is a top view of an oil distribution manifold useful with the appliance of Figure 11.

[0051] Figure 13 is another view of a sterilizing appliance as in Figure 1.

[0052] Figure 14 is a top view of an oil distribution manifold useful with the appliance of Figure 13.

[0053] Figure 15 is a perspective view of an adapter used with the sterilizer of Fig. 1.

[0054] Figure 16 is a sectional side elevational view of the adapter of Figure 15.

[0055] Figurel7 is one of a series of drawings showing a stage of exhausting a handpiece according to the invention and using the adapter of Figure 15.

[0056] Figure 18 is another of a series of drawings showing a stage of exhausting a handpiece according to the invention and using the adapter of Figure 15.

[0057] Figure 19 is another of a series of drawings showing a stage of exhausting a handpiece according to the invention and using the adapter of Figure 15.

[0058] Figure 20 is another of a series of drawings showing a stage of exhausting a handpiece according to the invention and using the adapter of Figure 15.

[0059] Figure21 is another of a series of drawings showing a stage of exhausting a handpiece according to the invention and using the adapter of Figure 15.

[0060] Figure 22 is another of a series of drawings showing a stage of exhausting a handpiece according to the invention and using the adapter of Figure 15. [0061] Figure 23 is another of a series of drawings showing a stage of exhausting a handpiece according to the invention and using the adapter of Figure 15.

[0062] Figure 24 is another of a series of drawings showing a stage of exhausting a handpiece according to the invention and using the adapter of Figure 15.

[0063] Figure 25 is another of a series of drawings showing a stage of exhausting a handpiece according to the invention and using the adapter of Figure 15.

[0064] Figure 26 is another of a series of drawings showing a stage of exhausting a handpiece according to the invention and using the adapter of Figure 15.

[0065] Figure 27 is a sectional, side view of one portion of the adapter of Figure 15.

[0066] Figure 28 is a is a sectional side view of a liquid supply source according to the invention.

[0067] Figure29 is another sectional side view of the source of Figure 28.

[0068] Figure30 is a side sectional view of the source of Figure 28 shown in place on a fluid reservoir such that the source supplies the reservoir.

[0069] Figure 31 is a side sectional view of the source of Figure 28 shown on another reservoir but in a closed or non-supplying mode.

[0070] Figure 32 is another view of a sterilizing appliance as in Figure 1, shown having a clip closing off one of the supply channels.

[0071] Figure 33 is a perspective view of one embodiment of the clip of Figure 32.

[0072] Figure 34 is another view of a sterilizing appliance as in Figure 1, also showing oil and water supply reservoirs and connecting fluid channels therebetween. Summary of the Invention

[0073] There is provided according to the invention, a sterilizing or sterilizing and lubricating appliance for dental handpieces of the type having an operating end and an attachment end as such handpieces are conventional in the art. According to one aspect of the invention, a sterilizing appliance for at least one dental handpiece comprises a steam chamber; means for removably affixing the handpiece in said steam chamber; means for introducing steam to said steam chamber; said means for introducing steam including a manifold having a single entry port and at least four steam outlet ports; such that steam is substantially equally distributed from said single entry port to each of said outlet ports.

[0074] According to another embodiment of the invention a sterilizing and lubricating appliance for a plurality of dental handpieces, each of the type having an operating end and an attachment end, comprises a steam chamber; means for removably affixing at least one of the handpieces in said steam chamber; a lubricating oil inlet fluidly connected to the handpiece connecting end by a fluid supply channel, such that said fluid supply channel follows a preselected oil flow path; an oil supply manifold positioned in the flow path of said fluid channel; said oil supply manifold having an oil inlet and a plurality of oil supply outlets at substantially equal distance from said inlet; such that each of said oil outlets of said oil supply manifold receive a substantially equal amount of oil. The oil manifold may also be fluidly connected to a source of pressurized gas such that said gas is conveyed to said oil outlets of said oil supply manifold. Preferred Embodiments For Carrying Out The Invention

[0075] According to the present invention, a distribution manifold 10 (Figure 3) is provided which insures that the steam flow is evenly split between four paths 1 Ia, 1 Ib, lie and Hd with equal pressure drop along each path 11 a - 11 d.

[0076] Figure 1 shows a cross-section of autoclave chamber 20 and schematic of flows 21a, 21b, 21c, 21d and 21e during steam introduction and sterilization phases. [0077] Figure 2 shows a schematic of original Nitram design for steam distribution plumbing. Note that flow will be unequal between each of the four chamber entry ports due to differing pressure drops along different lengths of distribution plumbing. [0078] Figure 3 shows the inventive design. Steam flow is equally split and equally distributed to each of the four paths 1 Ia - 1 Id.

[0079] Figures 4 — 7 show a detailed drawing of the steam distribution manifold 10. [0080] The concept of multiple equal flow paths can be implemented in numerous ways other than the preferred embodiment:

• discrete plumbing (tubing and fittings) with equal path lengths

• differing numbers and locations of steam entry ports into the chamber

• plumbing or manifold with different path lengths, but with varying diameters or restriction orifices to produce the desired result of equal steam flow rates

• manifolds comprised of welded stainless steel tubing

• manifold formed integrally with the chamber

• any other similar means which produce the desired result of approximately equal steam flow rates through the multiple entry ports into the chamber [0081] Eliminates temperature overshoots during the autoclave cycle, thereby reducing possible damage or degradation of the sterilized articles.

[0082] Facilitates air exchange during steam delivery, reducing trapped-air cold-zones.

Reduces spatial temperature variations within the chamber and thereby reduces stabilization time. This also enables a reduction in overall cycle time without compromising autoclave lethality to infectious organisms.

[0083] To further address the above problems, there has been developed an inventive manifold and method to assure an adequate volume of oil to each handpiece regardless of differing flow resistances.

[0084] Figure 9 shows a cross-section of autoclave chamber and plumbing schematic having a distribution manifold 30, and Figure 10 shows the inside of distribution manifold 30.

[0085] Figure 11 shows the first step of the lubrication process. Oil pump 40b is turned on for approximately 3 seconds, sufficient time to fill the plumbing leading to the distribution manifold 30 and fill all six channels 30a - 30f in the distribution manifold.

Some oil may also be pumped into and through the handpieces 50, but that is not necessary at this stage. An inventive aspect is the equal volume of lubricant (not shown) in each of the six distribution channels 30a - 30f.

[0086] Figure 13 shows a second step of the inventive lubrication process. The air valve 40c is opened for approximately 6 seconds and the air pressure pushes the oil out through the plumbing and each channel in the distribution manifold 30a - 30f. This insures that an assured minimum volume of oil passes through and into each handpiece 50 regardless of the back-pressure restrictions in each handpiece. A mist of air and excess oil is vented to the drain 21a.

[0087] The inventive concept can be implemented in other ways including:

• plumbing or manifold with different path lengths, but with varying diameters to produce the desired result of equal oil volumes;

• a manifold comprised of welded stainless steel tubing or other fabrication means;

• additional manual or controlled valves to shut off oil flow to unused handpiece positions;

• various timings of oil and water flow;

• initial oil inj ection by means of air pressure rather than a pump.

[0088] This aspect of the invention provides for an assured minimum of lubricant to be delivered to each handpiece substantially simultaneously.

[0089] The innovation of pressurizing the entire backend of the handpiece (i.e. pressurized exhaust), was demonstrated through testing to force excess lubricant through the handpiece bearing assemblies, as desired.

[0090] Figure 15 shows a handpiece adapter 60 having a flange 61 for connection to the inventive device. Adapter 60 is also provided with a handpiece coupling 62 and an internal channel 63 fluidly connecting to the handpiece drive port when in place. An exhaust channel 64 is provided and connects between the handpiece drive port and the exhaust ports.

A) Handpiece coupled to adapter within automate

B) Oil delivered to handpiece C) Oil fills handpiece

D) Compressed air applied to remove excess oil (desire only an oil film on bearing surfaces)

E) Oil is moved by compressed air (out of the handpiece for pressurized exhaust, into the exhaust channels for other designs.

[0091] The precise details of the adapter are not critical to the inventive concept; any number manifolds, ports, valves, or connections could achieve the same purpose. The pressurizing function could be achieved within the unit rather than by its adapter.

[0092] The inventive adapter permits sufficient lubricant to be delivered to flush operational debris without leaving excess oil. It improves lubricant penetration to critical handpiece components.

[0093] To address these problems, the inventive adapter of Figure 27 is provided for conventional fixed back-end handpieces.

[0094] The adapter 70 has a base 71 having mounting holes 72 and fluid passages 73.

Adapter 70 also has an inner body 80 which is independently rotatable from base 71 and has holes 81 which are matable with holes in an attached handpiece.

[0095] O-rings 82 and 83 seal air and fluids between base 71 and inner body 80. Bias means such as coil spring 84 urges inner body 80 towards an attached handpiece.

[0096] This adapter design could be utilized in devices which lubricate dental handpieces, use air to expel excess lubricant from dental handpieces, clean dental handpieces, sterilize dental handpieces, or any combination thereof.

[0097] Straightforward variations to the design which result in the same features (two rotating elements, spring loading) will be obvious to those skilled in the art. [0098] Different arrangements of holes in the inner body to accommodate different back-end configurations, as commonly defined in ISO 9168. [0099] Allows fixed back handpieces to be installed within autoMate rinse-lube- sterilizer. Ease of user (less turns because of spring loading).

[0100] A threaded collar 90 is provided to thread onto a handpiece in a substantially conventional manner. A retaining ring 91 is to axially restrain the inner body. Retaining ring 91 is affixed to collar 90 such that both may rotate.

[0101] To address the above problem, there is provided a detergent tablet that can be loaded into the chamber prior to cycling and which will quickly dissolve in water to form a mild free-rinsing detergent solution during the wash cycle.

[0102] The detergent tablet is a formulation of a mild, neutral pH soap, of the proper amount to make a soap solution of proper concentration to remove oils, yet not leave a soap residue after rinsing. It is formed with effervescent materials to quickly dissolve when it is in contact with water.

[0103] The autoTAB is a 0.5 " diameter by 0.16" thick white effervescent tablet formulated to quickly dissolve, remove oil residue and then freely rinse away. [0104] The tablet is designed to be placed in the autoMate prior to cycling, and then activate, releasing detergent, with the introduction of water at the start of the wash cycle. The detergent is medical grade, free-rinsing and non-toxic. After thoroughly rinsing the articles of sterilization the detergent is drained away, and fresh water is introduced to the chamber to facilitate rinsing, (see cycle description attached).

[0105] In one case, the tablet would be used in an automated dental article lube-rinse- sterilize reprocessing device. ("Reprocessing" includes lubrication, washing, cleaning, rinsing, disinfection, sterilization, or any combination thereof. "Dental article" includes dental handpieces, attachments, motors, static instruments, mirrors, hand tools, tips, and the like.) [0106] Other contemplated forms which would also solve the stated problem include:

• detergent powder in a single-use bag, the bag being made of a material which dissolves in water (eg corn-starch based plastics)

• detergent powder in a permeable bag, similar to a "tea-bag"

• effervescent detergent powder in a pre-measured unit dose bag or other container, which the user empties into the chamber

• detergence powder which readily dissolves, although without the effervescent feature

• effervescent detergent powder in a bulk container which the user measures into the chamber

• detergent formulations which not only remove oil but also remove and/or inactivate biological residue on the articles being reprocessed

[0107] Eliminates undesirable oil on exterior surfaces of handpiece deposited by the autoMate rinse-lube-sterilizer during lubrication.

[0108] To address the above problem, the invention provides a mixture of solvent and oil.

[0109] This mixture allowed a sufficient volume of liquid to be pumped through the handpieces to remove internal debris. The solvent component of the lubricant then evaporated during sterilization, leaving the desired film of oil for lubrication. [0110] The solvent-oil combination was carefully chosen to have a low viscosity oil suitable for dental handpieces and a non-toxic solvent that boils between ambient and sterilization temperature. Both liquids needed to be compatible with materials used in handpieces, non-toxic, and miscible. The solvent needed to have a low evaporation rate at room temperature, yet rapidly boil-off at sterilization temperatures.

[0111] The solvent selected, Isopar-C is an isopariffin hydrocarbon solvent from

Exxon-Mobile with many industrial uses. It is also known as light alkylation naphtha with CAS#64741-66-8. Isopar is a complex combination of hydrocarbons prodxiced by distillation of the reaction products of isobutane with monoolefmic hydrocarbons usually ranging in carbon numbers from C3 through C5. It consists of predominantly branched chain saturated hydrocarbons having carbon numbers predominantly in the range of C7 through ClO. The oil is a 100% synthetic hydrocarbon PAO (polyalphaolefin) manufactured by Nye lubricants.

[0112] The inventive function could be achieved with other types of oil and solvent which meet the criteria described above and with different ratios of oil and solvent.

[0113] Permits sufficient lubricant to be delivered to flush operational debris without leaving excess oil.

[0114] Improves lubricant penetration into critical handpiece components.

[0115] To address this problem, the present invention provides an oil bottle 100 with a spout 101 which only allows oil to flow when the bottle 100 is inserted into the oil reservoir fill port 102 (Figure 30), thereby removing the possibility of this use error.

[0116] Figure 28 shows the flow of oil with the pour spout 101 in the closed position while Figure 29 shows spout 101 in the open position with oil 103 flowing. [0117] Figure 30 shows oil bottle 100 inserted into an oil reservoir 104 inlet 102 thereby actuating spout 101 by compressing spring 110 and disengaging stopper 111 from a flow channel 112 in spout 102.

[0118] If oil bottle 100 is removed from oil reservoir 104 or inserted into water reservoir 113 with an inlet 114 suitably larger than inlet 102, then spring 110 causes spout 102 to be biased away from oil bottle 100 such that stopper 111 physically engages channel 112 stopping the flow of oil therethrough (Figures 28 and 31 respectively). [0119] The precise details of the nozzle are not critical to the inventive concept; any number of springs, type of springs, materials, sealing valve, and nozzle designs could achieve the same purpose. The keying function could be achieved by shape or length of nozzle and fill port rather than by its diameter (not shown). A feature projecting above the water fill port could prevent the user from depressing the bottle sufficiently to actuate (open) the bottle nozzle. The valve feature could be built into the reservoir fill ports rather than into the bottle. This feature helps to prevent user-error of pouring oil into water reservoir.

[0120] The invention provides a method of suspending sterilization indicators in a rinse-lube-sterilizer in the form of a simple clip 120 which addresses all of the above needs.

[0121] The clip 120 may be employed by simply snap-fitting it in place to close off any of the conduits for the drain 21a, oil 21b, air 21c (shown in Figure 32), water 21d and/or steam 21 e. Any suitable means of facilitating the use of clip 120 may be employed, such as mating grooves 130 or the like. Clip 120 may be fabricated from any material such as steel, plastic or the like, and may be provided with lodgements 121 for holding other components such as vials, steam strips (not shown) or the like.

[0122] Numerous means could be devised to perform a similar holding function. Ttie inventive design is unique in it's simplicity, low cost, ease of use, and small size.

[0123] Clip 120 helps to permit sterilization validation of unit such as in an installation setting, consistent to industry requirements. It also permits use of cycle verification steam strips commonly used in the dental industry.

[0124] The invention provides a method of quickly draining and flushing an attached water tank 113 via an automatic water supply line 140. Providing a means for a user to open a valve 141 placed in the device's water supply inlet 140, the water tank can be easily drained without the use of a siphon. The user is instructed to disconnect a water supply line 140 and route it to a drain (not shown) below the water tank 113, and them cycle the valve 141 via the unit's normal controls. Valve 141 may be any type of vaWe but is preferably a solenoid-type valve.

[0125] Other embodiments could be a drain plug or manual valve placed at the bottom of the water supply tank, placed so it can be easily accessed by the user (not shown).

[0126] This arrangement permits autoclave cleaning procedures for the inventive riLnse- lube-sterilizer, consistent with current industry practice.

Claims

What is claimed is:

1. A sterilizing appliance for at least one dental handpiece comprising: a steam chamber; means for removably affixing the handpiece in said steam chamber; means for introducing steam to said steam chamber; said means for introducing steam including a manifold having a single entry port and at least four steam outlet ports; such that steam is substantially equally distributed from said single entry port to each of said outlet ports.

2. A sterilizing and lubricating appliance for a plurality of dental handpieces, each of the type having an operating end and an attachment end, comprising: a steam chamber; means for removably affixing at least one of the handpieces in said steam chamber; a lubricating oil inlet fluidly connected to the handpiece connecting end by a fluid supply channel, such that said fluid supply channel follows a preselected oil flow path; ail oil supply manifold positioned in the flow path of said fluid channel; said oil supply manifold having an oil inlet and a plurality of oil supply outlets at substantially equal distance from said inlet; such that each of said oil outlets of said oil supply manifold receive a substantially equal amount of oil.

3. An appliance as in claim 2, wherein said manifold is also fluidly connected to a source of pressurized gas such that said gas is conveyed to said oil outlets of said oil supply manifold.