Patent Publication Number: US-2022211476-A1

Title: Apparatus and Method for Removing Amalgam and Waste Particles From Dental Office Suction Effluent

Description:
BACKGROUND OF INVENTION 
     This application is a continuation of U.S. application Ser. No. 16/446,734, filed on Jun. 20, 2019, which claims priority to U.S. application Ser. No. 15/239,214, filed Aug. 17, 2016, now issued as U.S. Pat. No. 10,342,647, which claims priority to U.S. application Ser. No. 14/519,959, filed Oct. 21, 2014, and claims priority to U.S. Prov. Patent App. Ser. No. 61/893,933, filed on Oct. 22, 2013, and U.S. Prov. Patent App. Ser. No. 62/013,019, filed on Jun. 17, 2014, all of which are incorporated by reference herein in their entirety. 
    
    
     The present invention relates to an apparatus and a method for removing amalgam and waste particles from dental office suction effluent. 
     In dentistry and in the present specification, the term “amalgam” generally refers to the alloys of mercury and other metals such as silver, tin, copper, which are used to form dental restorative materials (e.g., fillings). Amalgam was the restorative material of choice for many years due to its relatively low cost, ease of application, strength and durability. However, it has become less popular due to concerns over the toxicity of mercury, which is the major component of amalgam, the development of alternative materials that are more aesthetically pleasing, and also due to concerns over environmental pollution. 
     Although amalgam is less frequently used for new dental fillings than was the case some decades ago, amalgam nevertheless continues to comprise a significant portion of the metallic particle component of dental office effluent. This is the case because when old fillings comprising amalgam are drilled out and removed, amalgam particles are evacuated from the mouth as waste in such effluent. Furthermore, amalgam continues to be preferred for some tooth filling applications. 
     In addition to amalgam, dental office suction effluent includes saliva, rinsing fluid and solid particles such as aluminum oxides, which are used in abrasion treatments. It is important that the solid components of dental office suction effluent be separated from the liquid wastes before the latter are discharged into sanitary treatment systems. 
     The International Organization for Standardization (hereinafter “ISO”) has adopted a standard, which specifies the efficiency of amalgam separators in terms of the level of retention of amalgam based on a laboratory test (ISO 11143:2008). And there are many amalgam separators available that comply with such standard. 
     One amalgam separator known in the art is sold by SolmeteX, Inc. of Northborough, Mass. under the trade designation HG5®. This device consists of an upper chamber having two openings in an upper end and two openings in a lower end. One of the openings in the upper end is in fluid communication with a vacuum pump via piping, and the other opening in the upper end is in fluid communication with a dental suction wand. A collection chamber is removably connected to the lower end of the upper chamber. Waste is drawn into the upper chamber through the dental suction wand with air drawn into the upper chamber by the vacuum pump. Liquids and solids in the dental suction effluent stream are separated from the air to some degree in the upper chamber. The air flows out of the upper chamber to the vacuum pump. The liquids and solids flow under the force of gravity through one of the openings in the lower end of the upper chamber and then through straight tubing into the collection chamber. Solid particles settle and accumulate in the bottom of the collection chamber. Liquid waste is drawn up through a filter that extends into the collection chamber from the second opening in the lower end of the upper chamber. This opening is in fluid communication with a bypass conduit, which is connected to the piping to the vacuum pump. While the SolmeteX HG5® amalgam separator, and other similar products, are capable of separating amalgam and other solid particles from dental waste effluent streams, there is substantial room for improvement in terms of collection capacity, separation efficiency and ease of use. 
     BRIEF SUMMARY OF THE INVENTION 
     In view of the foregoing, the present invention is directed toward an apparatus and method for removing amalgam and waste particles from dental office suction effluent. The apparatus includes an upper chamber and a solids collection canister removably secured thereto. Dental office suction effluent drawn through a dental suction wand enters the upper chamber along a lateral flow path above a substantially cylindrical internal wall portion. A gas component of dental office suction effluent changes direction by more than 60°. before it exits the upper chamber through an exit port. A riser conveys a liquid and solids component of dental office suction effluent through a drain into the solids collection canister. A flow restrictor allows liquids and gases to exit the solids collection canister interior volume but prohibits solids from exiting the solids collection canister interior volume. 
     According to one aspect, an apparatus for removing amalgam and waste particles from dental office suction effluent comprises an upper chamber having an upper end and a lower end, and a solids collection canister removably secured to the lower end of the upper chamber. The upper chamber includes an upper portion, a central portion having a substantially cylindrical internal wall portion, and a lower portion having a basin portion. The upper portion, the central portion and the basin portion of the lower portion cooperate to define an upper chamber interior volume. An inlet provided in the upper portion of the upper chamber establishes a connection to an inlet line in fluid communication with at least one dental suction wand. An outlet provided in the lower portion of the upper chamber establishes a connection to an outlet line in fluid communication with a vacuum pump. The solids collection canister includes a top portion and a bottom portion which together define a solids collection canister interior volume. The top portion of the solids collection canister is provided with a first opening and a second opening. The first opening communicates with a drain provided in the basin portion of the upper chamber, and the second opening communicates with the outlet. A riser communicates with the first opening. The riser is adapted to convey liquids and solids of the dental office suction effluent flowing from the upper chamber interior volume through the drain and the first opening to the bottom portion of the solids collection canister. A flow restrictor communicates with the second opening. The flow restrictor is adapted to allow liquids and gases of the dental office suction effluent to exit the solids collection canister interior volume but prohibit solids of the dental office suction effluent from exiting the solids collection canister interior volume. 
     According to another aspect, an apparatus for removing amalgam and waste particles from dental office suction effluent comprises an upper chamber having an upper end, a lower end and a basin portion. The upper chamber defines a longitudinal axis. A solids collection canister removably secured to the lower end of the upper chamber. The solids collection canister includes a top portion provided with a first opening and a second opening. The first opening communicates with a drain provided in the basin portion of the upper chamber. An inlet is provided in the upper chamber for establishing a connection to an inlet line in fluid communication with at least one dental suction wand. The inlet is shaped and configured such that dental office suction effluent enters the upper chamber along a lateral flow path which is substantially perpendicular to the longitudinal axis of the upper chamber. An outlet is provided in the upper chamber for establishing a connection to an outlet line in fluid communication with a vacuum pump. An exit port is provided in the upper chamber and communicates with the outlet. The exit port discharges gases of dental office suction effluent entering the upper chamber through the inlet. A separate gas conduit is provided in the upper chamber and has a longitudinal axis substantially parallel to the longitudinal axis of the upper chamber. The gas conduit communicates with the exit port and the outlet for directing the discharged gases toward the outlet. A flow restrictor is located in the solids collection canister. The flow restrictor is adapted to allow liquids and gases of the dental office suction effluent to exit the solids collection canister but prohibit at least about 99% by weight of solids of the dental office suction effluent that enter the solid collection canister from exiting the solids collection canister. 
     According to yet another aspect, a method for removing amalgam and waste particles from dental office suction effluent comprises imparting a circular flow path to a dental office suction effluent entering an upper separation chamber of a separation apparatus; separating gases from the dental office suction effluent and discharging the separated gases from the upper separation chamber; directing the dental office suction effluent into a solids collection canister removably secured to a lower end of the upper chamber via a riser located in the solids collection canister; separating solids from the dental office suction effluent in the solids collection canister; and discharging liquids and gases of the dental office suction effluent through a flow restrictor located in the solids collection canister. 
     The foregoing and other features of the invention are hereinafter more fully described and particularly pointed out in the claims, the following description setting forth in detail certain illustrative embodiments of the invention, these being indicative, however, of but a few of the various ways in which the principles of the present invention may be employed. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of one embodiment of an apparatus for removing amalgam and waste particles from dental office suction effluent according to the present invention. 
         FIG. 2  is a partial section view of the upper portion of the apparatus shown in  FIG. 1 , which shows the primary flow path of dental office suction effluent drawn into the apparatus. 
         FIG. 3  is a side section view taken through the middle of the apparatus shown in  FIG. 1 , which also shows the primary flow path of dental office suction effluent drawn into the apparatus. 
         FIG. 4  is a perspective view of an upper chamber of the apparatus shown in  FIG. 1 , as viewed from the bottom. 
         FIG. 5  is a partial section view of a solids collection canister of the apparatus shown in  FIG. 1 . 
         FIGS. 6A-6D  are perspective views of another embodiment of an apparatus for removing amalgam and waste particles from dental office suction effluent according to the present invention. 
         FIG. 7  is a partial section view of the apparatus shown in  FIG. 6B . 
         FIG. 8  is a section view through an upper portion of an upper chamber of the apparatus shown in  FIG. 6A . 
         FIG. 9  is a section view of the apparatus shown in  FIG. 6B . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     It should, of course, be understood that the description and drawings herein are merely illustrative and that various modifications and changes can be made in the structures disclosed without departing from the present disclosure. In general, the figures of the exemplary apparatus for removing amalgam and waste particles from dental office suction effluent are not to scale. It should be appreciated that the term “plurality” means “two or more”, unless expressly specified otherwise. It will also be appreciated that the various identified components of the exemplary apparatus disclosed herein are merely terms of art that may vary from one manufacturer to another and should not be deemed to limit the present disclosure. 
       FIGS. 1-5  illustrate one embodiment of an apparatus  100  for removing amalgam and waste particles from dental office suction effluent according to the present invention. The apparatus  100  generally comprises an upper chamber  102  having an upper end  104  and a lower end  106 , and a solids collection canister  110  removably secured to the lower end  106  of the upper chamber  102 . The upper chamber  102  includes an upper portion  120 , a central portion  122  and a lower portion  124 . The upper portion  120  includes an outer wall portion  126  having a first wall portion  128  and a second wall portion  130  projecting outwardly from the first wall portion  128 . According to one aspect, the first wall portion  128  can be substantially hemispherical dome-shaped; although, this is not required. A flange  134  extends about a periphery  136  of the outer wall  126 . The flange  134  is shaped and configured to receive an upper part  140  of the central portion  122 , thereby securing the upper portion  120  to the central portion  122 . It should be appreciated that the connection between the flange  134  of the upper portion  120  and the central portion  122  can be in the form of a sealed interference fit allowing for the removal of the upper portion  120  from the apparatus  100 . In the alternative, the connection between the flange  134  of the upper portion  120  and the central portion  122  can be in the form of a permanent connection via, for example, an adhesive and/or welding. 
     The central portion  122  includes an outer wall  142  defined by the upper part  140  and a lower part  144 . The upper and lower parts  140 ,  142  of the central portion  122  together define a substantially cylindrical internal wall portion  150 , which in the depicted embodiment in an inner wall portion of the outer wall  142 . The inner wall portion  150  is adapted to impart a circular flow to the dental office suction effluent being drawn into the upper chamber  102 . The lower portion  124  of the upper chamber  102  includes a basin portion  156  defined by an outer wall  158  and a bottom wall  160 . Located about a periphery of an upper part  162  of the outer wall  158  is a flange  164  shaped and configured to receive the lower part  144  of the central portion  122 , thereby securing the lower portion  124  to the central portion  122 . Again, it should be appreciated that the connection between the flange  164  of the lower portion  124  and the central portion  122  can be in the form of a sealed interference fit allowing for the removal of the basin portion  156  from the apparatus  100 . In the alternative, the connection between the flange  164  of the lower portion  124  and the central portion  122  can be in the form of a permanent connection via, for example, an adhesive and/or welding. As better illustrated in  FIG. 3 , the upper portion  120 , the outer wall  142  (i.e., the substantially cylindrical internal wall portion  150 ) of the central portion  122  and the basin portion  156  of the lower portion  124  cooperate to define an upper chamber interior volume  170 . 
     An inlet  180  is provided in the upper portion  120  of the upper chamber  102  for establishing a connection to an inlet line (not shown) in fluid communication with at least one dental suction wand (not shown). The inlet  180  is configured such that dental office suction effluent drawn through the at least one dental suction wand enters the upper portion  120  of the upper chamber  102  along an initial lateral flow path into the upper portion  120  and then a circular flow path through the upper portion  120  above the internal wall portion  150  of the central portion  122  (the lateral/circular flow path shown by arrows “A 1 ” in  FIGS. 1-3 ). The term “lateral” as used herein means that the flow path is substantially sideways or horizontal (i.e., perpendicular) relative to a longitudinal axis defined by the upper chamber  102 , and the term “circular” as used herein mean a flow path substantially around the longitudinal axis of the upper chamber  102 . It should be appreciated that the use of the substantially hemispherical domed-shaped first wall portion  128  of the upper portion outer wall  126  allows the incoming dental office suction effluent to quickly change direction as it enters the upper portion  120  of the apparatus  100 . 
     With reference to  FIGS. 2 and 3 , an exit port  186  is provided in the upper portion  120 . The exit port  186  can be defined by the second wall portion  130  of the upper portion outer wall  126  together with an internal divider  188  formed in the upper portion  120  to separate the inlet  180  from the exit port  186 . As depicted, the divider  188  includes a cylindrical section  190  and a curved section  192  extending from the cylindrical section and into engagement with an interface of the first and second wall portions  128 ,  130  adjacent the inlet  180 . The first wall portion  128  together with the divider  188  define a circular flow path for the dental office suction effluent being drawn into the upper portion  120  of the upper chamber  102 . According to one aspect, the exit port  186  is so arranged such that gases of dental office suction effluent entering the upper chamber  102  through the inlet  180  has to change direction by more than at least 50°, and more preferably at least 60°, before the gases can exit the upper chamber  102  through the exit port  186 . In  FIGS. 1-3 , the primary flow of gases through the upper chamber  102  is illustrated using arrows “A 2 ”. The dental office suction effluent is permitted to expand as it enters the upper portion  120  of the apparatus  100 . The expansion and the change of flow direction in the upper portion  120  help separate gases from liquids and solids of the dental office suction effluent being drawn into the apparatus  100 . The divider  188  defines an expansion/deceleration zone within the upper chamber interior volume  170 , which further assists in separating liquids and solids from the intake stream. 
     An outlet  200  is provided in the lower portion  124  for establishing a connection to an outlet line (not shown) in fluid communication with a vacuum pump (not shown). As best shown in  FIGS. 1-3 , the central portion  122  includes a columnar portion  202  having a longitudinal axis substantially parallel to the longitudinal axis defined by the upper chamber  102 . The columnar portion  202  can be defined by an arcuate shaped outer wall  204  and the internal wall portion  150 . The columnar portion  202  is further separated from the upper chamber interior volume  170  by the internal wall portion  150  of the central portion  122 . The columnar portion  202  is in communication with the exit port  186  and the outlet  200  and cooperates with the upper portion  120  and the lower portion  124  to define a gas conduit  210  for gases of the dental office suction exiting the upper chamber interior volume  170  through the exit port  186  to flow out of the outlet  200 . 
     A flow path for liquids and solids of the dental office suction effluent are illustrated using arrows “A 3 ” in  FIGS. 1-3 . The liquids and solids of the dental office suction effluent travel along the substantially cylindrical internal wall portion  150  of the central portion  122  of the upper chamber  102  and, predominantly by the force of gravity, flow into the basin portion  156  of the lower portion  124 . 
     The upper portion  120  and the lower portion  124  of the upper chamber  102  can be formed of non-transparent or non-translucent materials. To comply with ISO standards, the central portion  122  is preferably formed of transparent or translucent materials. As depicted in  FIG. 2 , the central portion  122  is defined by the pair of stacked parts  140 ,  144 , which can be common shaped and sized parts  220 . It should be appreciated that more or less than the depicted number of parts  220  can be used to form the central portion  122 . For example, a plurality of parts  220  can be formed and joined together intermediate the upper portion  120  and the lower portion  124 , if desired. It should be appreciated that the materials utilized for the upper chamber  102  are polymeric in nature, and are joined using conventional methods (e.g., adhesives and/or welding). 
     With reference to  FIG. 3 , the solids collection canister  110  includes a top portion  230  and a bottom portion  232 . The bottom portion  232  can have an outer circumference that is greater than an outer circumference of the top portion  230 ; although, this is not required. The top portion  230  includes and upper end portion  236  releasably secured to the basin portion  156  of the upper chamber lower portion  124 . In the depicted embodiment, a pair of circumferentially spaced fastening members  238  which together with the bottom wall  160  of the basin portion  156  define a recess  240  dimensioned to receive the upper end portion  236  (see  FIG. 4 ). Once properly positioned opposed end portions of one fastening member  238  are connected to corresponding end portions of the other fastening member  238  thereby securing the upper end portion  238  of the top portion  230  to the basin portion  156 . As best depicted in  FIGS. 3 and 5 , the upper end portion  236  can include a circumferential groove  246  dimensioned to receive a seal  248  (such as an O-ring) which provides a leak-tight connection between the upper chamber  102  and the solids collection canister  110 . Further, to provide for a compact apparatus  100 , a longitudinal axis defined by the solids collection canister  110  can be aligned (i.e., coaxial) with the longitudinal axis of the upper chamber  102 . 
     A lower end portion  250  of the top portion  230  is joined to an upper end portion  252  of the bottom portion  232  by a circumferential seam  256  to define a solids collection canister interior volume  260 . According to one aspect depicted in  FIG. 3 , the circumferential seam  256  is defined by a flange  262  located on the lower end portion  250  overlapping the upper end portion  252 , which is located on the outside of the lower end portion  250 . An adhesive can be applied to the circumferential seam  256  (to define a glue joint) to permanently affix the top and bottom portions  230 ,  232  of the solids collection canister  110 .  FIG. 5  illustrates an alternative configuration for the circumferential seam  256 ′ between the top portion  230  and the bottom portion  232 . It will be appreciated that other seam techniques could be utilized without departing from the invention. 
     As perhaps best illustrated in  FIG. 5 , the top portion  230  of the solids collection canister  110  is provided with top wall  270  including a first projection  272  having a first opening  274  and a second projection  276  having a second opening  278 . The first opening  274  communicates with a drain  280  provided in the bottom wall  160  of the basin portion  156  of the upper chamber  102  (see  FIG. 4 ). The second opening  278  communicates with an inlet port  282  (which communicates with the outlet  200 ) also provided in the bottom wall  160  of the basin portion  156  (see  FIG. 4 ). In the assembled condition of the apparatus  100 , the first projection  272  is received in the drain  280  and the second projection  276  is received in the inlet port  282 . To provide for a sealed connection between these components, each of the first and second projections  272 ,  276  includes a respective circumferential groove  286 ,  288  for receiving a respective seal (i.e.,OO-ring)  290 ,  292  (see  FIG. 3 ). 
     The solids collection canister  110  further comprises a riser  300  that conveys liquids and solids of the dental office suction effluent flowing from the upper chamber interior volume  170  through the drain  280  and the first opening  274  to the bottom portion  232  of the solids collection canister (see  FIG. 5 ). According to one embodiment, the riser  300  is an elongated cylindrical shaped member having a longitudinal axis substantially parallel to the longitudinal axis of the solids collection canister  110 . According to one aspect, an upper end  302  of the riser  300  is secured in a boss  304  depending from the top wall  270  of the top portion  230 , the boss  304  having an axis that is coincident with an axis of the drain  280 . A lower end  306  of the riser  300  includes a tip portion  310  having an exit opening  312 . The tip portion  310  is shaped and configured to direct liquids and solids of the dental office suction effluent conveyed thereby toward an inner wall  316  of the bottom portion  232  of the solids collection canister  110 . According to one aspect, the tip portion  310  includes an inner surface  322  canted upwardly toward the top wall  270  which directs liquids and solids of the dental office suction effluent away from a flow restrictor  320 . 
     As noted, the solids collection canister  110  further includes the flow restrictor  320 , which is mounted to and depends from the top wall  270  of the top portion  230 . According to one aspect, the flow restrictor has an upper end  322  secured in a second boss  324  depending from the top wall  270 , the second boss  324  having an axis that is coincident with an axis of the inlet port  282 . A cap  326  can be secured to a lower end  328  of the flow restrictor  320 . The flow restrictor  320  is in fluid communication with the outlet  200  via the second opening  278  in the top portion  230  and a lower conduit  330  formed in the basin portion  156  of the lower portion  124  of the upper chamber  102  (see  FIGS. 3 and 4 ). The lower conduit  330  is in communication with the inlet port  282  and the outlet  200  and extends in a direction substantially perpendicular to the longitudinal axis of the upper chamber  102 . The flow restrictor  320  allows liquids and gases of the dental office suction effluent to exit the solids collection canister interior volume  260 , but prohibits solids of the dental office suction effluent from exiting the solids collection canister interior volume  260 . This can be accomplished through the use of a tubular element  336 , which is provided with circumferential slits  338  dimensioned to prevent the passage of solids larger than a predetermined size. Within the flow restrictor  320 , a porous material (not shown) can be provided (e.g., sand media), which allows the passage of liquids and gases, but does not allow for the passage of solids. 
     With reference to  FIG. 5 , the inner wall  316  of the bottom portion  232  of the solids collection canister  110  can be provided with a plurality of upwardly extending flutes  350 . Similarly, a bottom wall  352  of the bottom portion  232  can be provided with a plurality of flutes  354 , which can be contiguous with the flutes  350 . The flutes  350 ,  354  provide strength and also enhance separation of solids from liquids. The bottom wall  352  of the solids collection canister  110  can further include an indentation or punt  356 , which encourages solids of the dental office suction effluent to settle initially along a perimeter of the solids collection canister interior volume  260 . The punt  356  also makes it easy to hold and maintain the solids collection canister  110  in position with one hand with respect to the upper chamber  102  during removal and replacement operations. 
     As indicated previously, in the depicted embodiment, the bottom portion  232  of the solids collection canister  110  has an outer circumference that is greater than the outer circumference of the top portion  232 . This allows the solids collection canister  110  to collect a larger volume (e.g., 1.5 L) of solids of the dental office suction effluent than could otherwise be collected if the dimensions were the same or if the bottom portion  232  was smaller than the top portion  230 . This configuration can be utilized as a replacement for solids collection receptacles on known amalgam separators, such as the HG5® unit presently being sold by SolmeteX, Inc., which only are able to collect 1.0 L of solids. This reduces the frequency of canister changes. An outer ribbing  360  can also be provided on the solids collection canister  110  to improve its strength and also the ease by which it can be gripped (see  FIG. 1 ). It should be appreciated that the solids collection canister  110  can be replaced once a predetermined volume (e.g., 1.5 L) of solids has been collected therein. 
       FIG. 6A  through  FIG. 9  depict another embodiment of an apparatus  400  for removing amalgam and waste particles from dental office suction effluent according to the present invention. The apparatus  400  has the same functionality and defines the same flow paths as the apparatus  100  shown in  FIGS. 1-5 , but includes additional features, which are discussed in greater detail below. 
     As shown in  FIGS. 6A-6D , the apparatus  400  generally comprises an upper chamber  402  having an upper end  404  and a lower end  406 , and a solids collection canister  410  removably secured to the lower end of the upper chamber. The upper chamber includes an upper portion  420 , a central portion  422 , and a lower portion  424 . The upper portion  420  includes an outer wall portion  426  having a first wall portion  428  and a second wall portion  430  projecting outwardly from the first wall portion  128 . According to one aspect, the first wall portion  428  can be substantially hemispherical dome-shaped; although, this is not required. 
     With particular reference to  FIGS. 7 and 9 , the central portion  422  includes a substantially cylindrical internal wall portion  440  adapted to impart a circular flow to the dental office suction effluent being drawn into the upper chamber  402 . The lower portion  424  of the upper chamber  402  includes a basin portion  442 . The basin portion  442  is defined by a vertical wall  444  and a bottom wall  446 . The upper portion  420 , the substantially cylindrical internal wall portion  440  of the central portion  422  and the basin portion  446  of the lower portion  424  cooperate to define an upper chamber interior volume  450 . 
     The upper portion  420  and the lower portion  424  of the upper chamber  402  can be formed of non-transparent or non-translucent materials. To comply with ISO standards, the central portion  422  is preferably formed of transparent or translucent materials. It should be appreciated that the materials utilized for the upper chamber  402  are polymeric in nature, and can be joined using conventional methods (e.g., adhesives and/or welding). For example, as best depicted in  FIGS. 7 and 9 , one manner for connecting the upper portion  420  to the central portion  422  and the central portion  422  to the lower portion  424  is to form grooves  452 ,  454  at the peripheral edges of the central portion  422 , which receive straight peripheral edges of the upper and lower portions, respectively. This configuration improves the moldability of the parts, and ensures an accurate seal between the portions  420 ,  422 ,  424  that comprise the upper chamber  402 . 
     An inlet  460  is provided in the upper portion  420  of the upper chamber  402  for establishing a connection to an inlet line (not shown) in fluid communication with at least one dental suction wand (not shown). The inlet  460  is configured such that dental office suction effluent drawn through the at least one dental suction wand enters the upper portion  420  of the upper chamber  402  along an initial lateral flow path into the upper portion  420  and then a circular flow path through the upper portion  420  above the internal wall portion  440  of the central portion  422 . Again, it should be appreciated that the use of the substantially hemispherical domed-shaped first wall portion  428  of the upper portion outer wall  426  allows the incoming dental office suction effluent to quickly change direction as it enters the upper portion  420  of the apparatus  400 . 
     With reference to  FIGS. 7-9 , an exit port  466  is provided in the upper portion  420 . The exit port  466  can be defined by the second wall portion  430  of the upper portion  420  together with an internal divider  468  formed in the upper portion  420  to separate the inlet  460  from the exit port  466 . As depicted, the divider  468  includes a cylindrical section  470  and a pair of curved sections  472 ,  474  extending from the cylindrical section and into engagement with an interface of the first and second wall portions  428 ,  430  adjacent the inlet  460 . The first wall portion  428  together with the divider  468  define a circular flow path for the dental office suction effluent being drawn into the upper portion  420  of the upper chamber  402 . According to one aspect, the exit port  466  is so arranged such that gases of dental office suction effluent entering the upper chamber  402  through the inlet  460  has to change direction by more than at least 50°, and more preferably at least 60°, before gases can exit the upper chamber  402  through the exit port  466 . The dental office suction effluent is permitted to expand as it enters the upper portion  420  of the apparatus  400 . The expansion and the change of flow direction help separate gases from liquids and solids of the dental office suction effluent. The divider  468  defines an expansion/deceleration zone  476  within the upper chamber interior volume  450 , which further assists in separating liquids and solids from the intake stream (see  FIG. 7 ). 
     An outlet  480  is provided in the lower portion  424  for establishing a connection to an outlet line (not shown) in fluid communication with a vacuum pump (not shown). The central portion  422  includes a columnar portion  482  and the lower portion  426  includes a corresponding columnar portion  484 . Each columnar portion  482 ,  484  has a longitudinal axis substantially parallel to a longitudinal axis defined by the upper chamber  402 . As best depicted in  FIGS. 7 and 9 , the columnar portion  482  can be defined by an arcuate shaped outer wall  486  and the internal wall portion  440 , which separates the columnar portion  482  from the upper chamber interior volume  450 . The columnar portion  484  can be defined by an arcuate shaped outer wall  488  and the wall  444  of the basin portion  442 . Each columnar portion  482 ,  484  is in communication with the exit port  466  and the outlet  480  and cooperates with the upper portion  420  and the lower portion  424  to define a gas conduit  490  for gases of the dental office suction exiting the interior volume  450  through the exit port  466  to flow out of the outlet  480 . Similar to the function of the apparatus  100 , liquids and solids of the dental office suction effluent travel along the substantially cylindrical internal wall portion  440  of the central portion  422  of the upper chamber  402  and, predominantly by the force of gravity, flow into the basin portion  446  of the lower portion  424 . 
     With reference to  FIGS. 6A-6D , the solids collection canister  410  includes a top portion  500  and a bottom portion  502 . The bottom portion  502  can have an outer circumference that is greater than an outer circumference of the top portion  500 ; although, this is not required. The top portion  500  includes and upper end portion  506  releasably secured to the basin portion  442  of the upper chamber lower portion  424 . As best depicted in  FIGS. 7 and 9 , the upper end portion  506  can include a circumferential groove  510  dimensioned to receive a seal  512  (such as an O-ring) which provides a leak-tight connection between the upper chamber  402  and the solids collection canister  410 . To provide for a compact apparatus  400 , a longitudinal axis defined by the solids collection canister  410  can be aligned (i.e., coaxial) with the longitudinal axis of the upper chamber  402 . A lower end portion  516  of the top portion  230  is joined to an upper end portion  518  of the bottom portion  502  by a circumferential seam  520  to define a solids collection canister interior volume  524 . An adhesive can be applied to the circumferential seam  520  to permanently affix the top and bottom portions  500 ,  502 . Again, it will be appreciated that other seam techniques could be utilized without departing from the invention. 
     With continued reference to  FIGS. 7 and 9 , the top portion  500  of the solids collection canister  410  is provided with top wall  530  including a first projection  532  having a first opening  534  and a second projection  536  having a second opening  538 . The first opening  534  communicates with a drain  540  provided in the bottom wall  446  of the basin portion  442  of the upper chamber  402 . The second opening  538  communicates with an inlet port  542  also provided in the bottom wall  446  of the basin portion  442 . In the assembled condition of the apparatus  400 , the first projection  532  is received in the drain  540  and the second projection  536  is received in the inlet port  542 . To provide for a sealed connection, each of the first and second projections  532 ,  536  can include a circumferential groove for receiving a seal (i.e., O-ring) (see  FIG. 9 ). 
     The solids collection canister  410  further comprises a riser  550  mount to and depending from the top wall  446  that conveys liquids and solids of the dental office suction effluent flowing from the upper chamber interior volume  450  through the drain  540  and the first opening  534  to the bottom portion  502  of the solids collection canister  410 . The riser  550  is shaped and configured similar to riser  300 , and the manner for securing the riser  550  to the top wall  446  is similar to the connection of the riser  300  to the top wall  270 . Therefore, further description of these features of the apparatus  400  is omitted for conciseness. 
     A flow restrictor  560  is mounted to and depends from the top wall  446 . Because the manner for securing the flow restrictor  560  to the top wall  446  is similar to the connection of the flow restrictor  320  to the top wall  270 , further description of these features of the apparatus  400  will be omitted for conciseness. The flow restrictor  560  is in fluid communication with the outlet  480  via the second opening  538  in the top portion  500  and a lower conduit  570  formed in the basin portion  442  of the lower portion  424  of the upper chamber  402  (see  FIGS. 7 and 9 ). The lower conduit  570  is in communication with the inlet port  542  and the outlet  480  and extends in a direction substantially perpendicular to the longitud°inal axis of the upper chamber  402 . The flow restrictor  560  allows liquids and gases of the dental office suction effluent to exit the solids collection canister interior volume  524 , but prohibits solids of the dental office suction effluent from exiting the solids collection canister interior volume  524 . 
     In the depicted embodiment, the flow restrictor  560  can be formed of an inert micro-fiberglass material bonded with a stable resin, randomly set into a multi-layer composite. In the present embodiment of the invention, the material of the flow restrictor  560  has a 3 micron absolute rating. In the illustrated flow restrictor  560 , the fiberglass material is co-pleated with inner and outer support layers, which can be made of corrosion resistant materials such as metal (stainless steel) and/or plastic. It is important that the material, at gravity feed, have a low pressure differential across the separation media. Use of a flow restrictor having a configuration as described should improve the separation efficiency of the amalgam separator apparatus  400  substantially, with amalgam particle separation efficiencies of 99% or greater being expected in accordance with testing under the ISO 11143:2008 standard. 
     With reference to  FIG. 9 , an inner wall  576  of the bottom portion  502  of the solids collection canister  410  can be provided with a plurality of upwardly extending flutes  580 . Similarly, a bottom wall  582  of the bottom portion  502  can be provided with a plurality of flutes  584 , which can be contiguous with the flutes  580 . The flutes  580 ,  584  provide strength and also enhance separation of solids from liquids. The bottom wall  582  of the solids collection canister  410  can further include an indentation or punt  586 , which encourages solids of the dental office suction effluent to settle initially along a perimeter of the solids collection canister interior volume  524 . 
       FIG. 8  depicts mounts  590 , which are formed in the upper portion  420 . The mounts  590  can be connected to brackets or hardware (not shown) allowing the upper chamber  402  to be fixedly mounted to a wall or other location. It will be appreciated that the location and configuration of the mounts  590  is not per se critical, and that a variety of different mounting arrangements could be used. 
     In its broadest sense, an exemplary method for removing amalgam and waste particles from dental office suction effluent comprises providing an apparatus as disclosed herein, and suctioning waste from a patient&#39;s mouth through a dental office suction effluent wand in fluid communication with the apparatus. Once the interior volume of the solids collection canister has been sufficiently filled with solid particles (e.g., 1.5 L), the entire solids collection canister is removed from the upper chamber, and a new solids collection canister is secured to the upper chamber in its place. The solids collection canister filled with collected solids can be packed and shipped to a recycling facility, where the metals are recovered. 
     According to one aspect, a method for removing amalgam and waste particles from dental office suction effluent comprises imparting a circular flow path to a dental office suction effluent entering an upper separation chamber of a separation apparatus; separating gases from the dental office suction effluent and discharging the separated gases from the upper separation chamber; directing the dental office suction effluent into a solids collection canister removably secured to a lower end of the upper chamber via a riser located in the solids collection canister; separating solids from the dental office suction effluent in the solids collection canister; and discharging liquids and gases of the dental office suction effluent through a flow restrictor located in the solids collection canister. The method can further comprise discharging the separated gases through a separate gas conduit provided in the upper chamber. The method can further comprise conveying liquids and solids of the dental office suction effluent flowing from the upper chamber toward an inner wall of the solids collection canister. 
     The device and method are preferably capable of handling an effluent flow rate of at least one 1 L per minute. The flow rate of effluent is primarily governed by the flow restrictor. The amount of effluent flowing into the device will vary depending upon the number of chairs in use. When the effluent inflow temporarily exceeds the maximum flow rate, the effluent will accumulate in the upper chamber, and then gradually drain off through the solids collection canister when inflow rates diminish. Thus, the device can be used in conjunction with multiple dental chairs simultaneously. 
     Additional advantages and modifications will readily occur to those skilled in the art. Therefore, the invention in its broader aspects is not limited to the specific details and illustrative examples shown and described herein. Accordingly, various modifications may be made without departing from the spirit or scope of the general inventive concept as defined by the appended claims and their equivalents.