Backflow prevention system in suctioning apparatus

A dental apparatus backflow prevention system for substantially preventing contaminant backflow into a patient's mouth, the system comprising:

• a saliva ejector tube for insertion into a patient's mouth and removal of fluid therefrom upon application of a vacuum;
• a backflow prevention device operably connected to the saliva ejector tube to receive the fluid therefrom, the backflow prevention device comprising:
• a distal portion having an internal valve seat;
• a proximal portion coupled with the distal portion and constructed for operative connection to a vacuum source, said distal and proximal portions forming a housing with an inlet formed in the distal portion and an outlet formed in the proximal portion, the housing being constructed such that the vacuum source draws fluid within the housing only from the inlet to the outlet;
• and
• valve componentry disposed within the backflow prevention device, the valve componentry comprising:
• a biasing member operably coupled with the housing;
• and
• a seating mechanism operably supported by the housing to be biased by the biasing member to automatically engage the valve seat and prevent contaminant backflow upon release of vacuum, the seating mechanism automatically disengaging from the valve seat and allowing fluid flow toward the vacuum source upon application of the vacuum;
• wherein the biasing member comprises a plurality of sprung, bendable legs constructed to bias the seating mechanism toward the valve seat, each leg including at least one notch.

A dental apparatus backflow prevention system for substantially preventing contaminant backflow into a patient's mouth, the system comprising:

• a saliva ejector tube for insertion into a patient's mouth and removal of fluid therefrom upon application of a vacuum;
• a backflow prevention device operably connected to the saliva ejector tube to receive the fluid therefrom, the backflow prevention device comprising:
• a distal portion;
• a proximal portion coupled with the distal portion and constructed for operative connection to a vacuum source, said distal and proximal portions forming a housing with an inlet formed in the distal portion and an outlet formed in the proximal portion, the housing being constructed such that the vacuum source draws fluid within the housing from the inlet to the outlet, one of the distal and proximal portions supporting an internal valve seat;
• and
• valve componentry disposed within the backflow prevention device, the valve componentry comprising:
• a biasing member operably coupled with the housing;
• and
• a seating mechanism operably supported by the housing to be biased by the biasing member to automatically engage the valve seat to define a plane of contact and prevent contaminant backflow upon release of vacuum, the seating mechanism automatically disengaging from the valve seat and allowing fluid flow toward the vacuum source upon application of the vacuum;
• wherein the seating mechanism includes an engagement member defining a curved shape for engaging the valve seat in the plane of contact the curved shape also extending through the plane of contact, further wherein the biasing member comprises a lever arm extending away from the engagement member.

A dental ejector tip for substantially preventing contaminant backflow into a patient's mouth, the dental ejector tip comprising:

• a saliva ejector tube for insertion into a patient's mouth and removal of fluid therefrom upon application of a vacuum;
• a backflow prevention device operably connected to the saliva ejector tube, free of a valve member between the backflow prevention device and the saliva ejector tube, to receive the fluid therefrom, the backflow prevention device comprising:
• a distal portion having an inlet, the distal portion being directly connected to the saliva ejector tube at the inlet, the saliva ejector tube and distal portion being constructed to provide direct fluid communication from the patient's mouth to the inlet at all times;
• a proximal portion having an outlet, the proximal portion being coupled with the distal portion and constructed for readily removable connection at the outlet to a vacuum source, the distal portion and the proximal portion being constructed such that the vacuum source draws fluid within the housing only from the inlet to the outlet, the distal portion and the proximal portion defining a valve chamber;
• and
• valve componentry disposed within the backflow prevention device, the valve componentry automatically preventing contaminant backflow upon release of vacuum and automatically allowing fluid flow toward the vacuum source upon application of the vacuum, the valve componentry comprising a valve seat, an engagement member defining a curved shape for engaging the valve seat, and a biasing member comprising a lever arm extending away from the engagement member to bias the engagement member toward the valve seat;
• wherein the ejector tip comprising both the saliva ejector tube and the backflow prevention device is constructed for detachment from the vacuum source and disposal as a unit between patients.