Most dental patients have some level of anxiety or fear associated with dental procedures, particularly those procedures involving a dental drill. While dental anxiety is common, this anxiety has often risen to the level of fear or even dental phobia in a significant percentage of the population. Dental anxiety, fear, or phobia is most often caused by previous, unpleasant dental experiences resulting in trauma due to physical and/or psychological pain. Other contributing factors include, but are not limited to, feeling trapped, a loss of control, physical pain and the helplessness and vulnerability associated with many dental procedures.
Fear of dental procedures resulting in avoiding the dentist can have adverse physical and emotional consequences. Dental health will certainly suffer, possibly leading to physical and psychological problems, such as loss of self-esteem and even depression. Often patients who avoid regular dental care believe that all dental treatment is painful. In addition, these patients fear the dentist may be unresponsive to their expression of pain, either intentionally or unintentionally, leaving them feeling helpless and in pain.
Testing has shown that patient anxiety is reduced and pain tolerance is increased when the patient has a sense of control over the source of the pain. Accordingly a dentist may be more efficient with a less anxious patient. Previous attempts to alleviate patient anxiety include predetermined signals to the dentist or even paddles the patient could raise to alert the dentist to pain. Glen et al., U.S. Pat. No. 4,810,996 even provides a patient controlled audible alarm indicating a level or degree of pain to the dentist. These systems have proven unsuccessful, in part, because a sudden or erratic movement or loud noise may startle a dentist during a drilling procedure. Further, anticipation of a sudden erratic movement or loud noise would likely increase the anxiety felt by the dentist during such procedures. More importantly, these methods do not address the helplessness felt by patients. Even when a patient does alert the dentist to pain, there is no guarantee the dentist will stop the drilling procedure. The dentist may choose to continue because the procedure is “almost done” thus reducing the sense of security of the patient.
Previous efforts to reduce patient anxiety related to pain and helplessness include a patient interrupt switch. Reference in this regard, Smithwick et al., U.S. Pat. No. 4,767,327, which discloses a patient control mechanism for an air conduit of a dental unit using a three valve mechanism. However, the switch and valve arrangement, as depicted in FIGS. 1 and 3 of this reference, seems to allow undesirable results in some situations and/or in the hands of a nervous patient. For example, a single switch, in the patient's control, has the capability to both turn off and turn on the drill. In other words, in addition to stopping the drill in response to pain, the patient may inadvertently restart the drill at an inopportune moment creating a potentially dangerous situation. Because the valves operate sequentially in response to the patient, there is a small inherent delay between switch actuation and the cessation of rotation of the drill. This delay is caused, in part, as the air pressure is diverted to the second and third valves, and finally the air pressure decays in the line to the drill causing the drill to slow to a stop. The delay may be seen in the system in FIG. 3 of the patent, where it appears that the patient interrupt operates on valve 24, valve 22, and eventually closes valve 20 leaving a positive air pressure along the line that must be dissipated through pedal 16 and dental unit 14 before the drill stops. In addition, the line must repressurize after the system resets which may produce a noticeable delay in restarting the drill. A highly sensitive patient may sense and misinterpret the delay and depress the switch more than one time. A nervous patient may fiddle with the switch unintentionally causing one or more partial or full depressions to the switch. Disruptions to the airflow may create erratic or unpredictable drill rotation and even cause the cycling of power to the drill.
Additionally the Smithwick system appears to pose a significant problem for use with modern dental equipment. Typically the same pressurized air source that provides power to the dental hand piece also provides power to the dental chair and associated equipment. According to FIG. 3 of the Smithwick patent, valve 22 as connected to the compressed air source 18 seems to remove the air source completely. Used with modern dental equipment, the patient interrupt of Smithwick would not only stop the drill, but it would also remove power from the dental chair and associated equipment.
Additional shortcomings of the Smithwick system are related to its complexity and difficulty in implementation. Because the system requires diverting air pressure to numerous locations in the overall dental system, additional tubing must be installed each of the locations. Also the system requires three independent pneumatic valves installed at different locations. Pneumatic valves are sensitive to variations in air pressure at the source and include a decay time as the air pressure bleeds out of the system. As a result, instead of a desirable nearly instantaneous stop in response to the patient input, the drill of the prior art system will likely appear to gradually slow to a stop with the possibility of unintentionally being restarted by the patient.
It is therefore desirable to provide a dental patient anxiety and pain management system which overcomes at least one of the problems, shortcomings or disadvantages set forth above.