Auto Dispensing Prophy Angle

1. Auto Dispensing Prophy Angle Ari Katz Brendan LaBrecque Stefan Mag Matt Rao Nick Starno 1 2 . 0 4 . 0 7

2. The Cleaning Process Doriot Handpiece Disposable Prophy Angle Dentifrice (“Prophy Paste”) The duration of the average cleaning is approximately 5 - 10 minutes Dentifrice is reloaded up to one time per tooth (32 times) during cleaning Between 50-100% of a container of dentifrice is used per patient 2

3. Purpose Problem Statement: The amount of time a hygienist spends in an awkward position can be reduced and the dental cleaning procedure can be made more efficient. Objective: Integrate a dentifrice dispensation system into a disposable prophy angle to simplify the process and reduce the overall time of the procedure.

4. Benefits Allows cleaning to become one continuous process Reduces the duration of the cleaning Increases cleaning efficiency in hard to reach areas Reduces materials and sterilization processes required for packaging Improved ergonomics

5. Dentifrice Characteristics Before Use After 15 Seconds • A two-phase visco-elastic material comprised of abrasives, binders, humectants, and other agents • Viscosity: >300 Pa*s; Re<1 • Does not behave as a fluid • Composed of solid particles • Abrasive • Solid particles break down

6. Existing Patents 1 2 3

7. Design Requirements Required Systems • Dispensation Mechanism • Drive Mechanism • Dentifrice Storage • Size – must interface with standard handpiece, fit in any patient’s mouth, and maintain ergonomics. • Reliability & Ease of Use – must continuously dispense dentifrice at an acceptable rate or allow user control. • Safe and Sterile – must use biocompatible materials, can’t generate excessive heat, and must be manufactured to allow for sterilization processes. • Low Cost – currently the cost of a container of dentifrice and a disposable prophy angle is around 40 cents.

8. Initial Designs • Simple Design • Rifled Tube Integrates all Required Systems • Orifice Restricts Flow Rate • Spring Auger Drive Mechanism • Clutch Enabled User Control of Dispensation

9. Test 1 – Auger Dispensation Test Fixture Medium Grit Dentifrice Dremel Tool Scale Objectives: • Investigate the feasibility of using an auger as a dispensation mechanism • Establish a correlation between pitch and volumetric flow rate

10. Test 2 – Plunger Dispensation Objectives: • Investigate the feasibility of using a plunger as a dispensation mechanism Weight Plunger

11. Test 3 – Orifice Constriction • Objective: • Determine how much a reduction in orifice size restricts the flow of dentifrice AY AX Weight Scale Dremel Tool Test Configuration with Taper

12. Test 4 – Bend Radius Objectives: • Determine the feasibility of transporting dentifrice around a 90º bent flow path. Scale Bent Tube Fixture Dremel Tool Dentifrice Displacement

13. Test Conclusions • No constrictions • Effect of bend in flow path is minimal Auger or reservoir must be rotating relative to the other No plunger mechanism Higher pitch yields higher velocity and force

14. Revised Designs Design 1 Design 2 • Auger dispensation • Enables user control • Eliminates: • Orifice constrictions • Bent Spring • Excess friction and heat generation

15. Design 1 Spring Auger Bent Flow Path Clutch System User Control

16. Design 1 Prototype Testing Pre-Test Post-Test 16

17. Design 2 Straight Flow Path Spring Auger Brake System User Control

18. Design 2 Prototype Testing 18

19. Final Design

20. Questions 20