Oral hygiene devices employing an acoustic waveguide

Abstract

An oral hygiene device having an ultrasound transducer 22 and an acoustic waveguide 24 facilitating the transmission of ultrasonic acoustic energy to fluids in the oral cavity is disclosed. Preferred ultrasound operating parameters for operation in aqueous environments and in dental slurries are disclosed. Devices may incorporate a drive motor 16 for oscillating a device head 23, acoustic waveguide 24 and one or more bristle tuft(s) 26 at sonic frequencies, and preferred sonic operating parameters are also provided. Multi-element piezoelectric transducer assemblies 30, 40, and various control and communications features are disclosed. Oral hygiene devices disclosed herein achieve improved plaque and stain removal from the teeth as well as interproximal and subgingival regions, while enhancing the user experience, massaging the gums, stimulating dental tissue, and disrupting biofilm.

Description

CROSS-REFERENCE TO RELATED APPLICATION [0001] This application claims priority to U.S. Patent Application 60 / 677,577 filed May 3, 2005.REFERENCE TO GOVERNMENT SUPPORT [0002] One or more of the inventions disclosed herein were made with Government support under SBIR Contract No. 1-R43-DEO16761-01. The Government may have certain rights in one or more of those inventions.BACKGROUND OF THE INVENTION [0003] 1. Technical Field of the Invention [0004] The present invention relates generally to the field of oral hygiene devices and, more specifically, to the field of oral hygiene devices such as toothbrushes that employ sonic and / or ultrasonic acoustic mechanisms. [0005] 2. Brief Description of the Related Art [0006] Even the most effective existing power toothbrushes leave clinically significant plaque at tooth-to-tooth contact surfaces, at the gingival-tooth contact points, below the gingiva and beyond the direct reach of the bristles or other toothbrush components. Many oral hygiene dev...

AI Technical Summary

Benefits of technology

[0026] Within various embodiments, the present invention provides oral hygiene devices, such as toothbrushes, including manual (non-motorized) toothbrushes incorporating an ultrasound transducer and an acoustic waveguide structure, power (motorized) toothbrushes incorporating an acoustic waveguide structure, and power (motorized) toothbrushes incorporating both an ultrasound transducer and an acoustic waveguide structure. The acoustic waveguide structure, in combination with an ultrasound transducer and / or motor for generating oscillation at sonic frequencies, and optionally in combination with one or more bristle tufts, acts upon the microscopic bubbly flow within fluid in the operating environment to induce cavitation, acoustic streaming and / or acoustic microstreaming within the fluid. Oscillation of the brush head at sonic frequencies, in combination with emission of acoustic energy from the acoustic waveguide at ultrasound frequencies, and / or in combination with the oscillation of one or more bristle tufts, furthermore generates a favorable mouth feel, stimulates and massages the gums and other dental tissue and, in general, provides an improved dental cleaning experience.

[0027] An oral hygiene device such as a toothbrush, employing an acoustic waveguide in combination with an ultrasound transducer and / or a motor generating oscillations at sonic frequencies under the conditions described herein, provides improved cleaning properties and disruption of biofilm. As described in detail herein, oral hygiene devices according to the present invention are effective in increasing bubbly fluid flow by motion, including sonic motion, of the acoustic waveguide and promoting bubble formation by movement of the waveguide and / or one or more bristle tufts. Oscillation of the brush head at sonic frequencies moves and activates the bristle tips so that they cleanse tooth surfaces by means of direct bristle contact and also generates bubbles within the dental fluid surrounding the waveguide that, when exposed to acoustic energy at ultrasound frequencies, provide improved plaque and biofilm removal.

[0028] In embodiments employing an ultrasound transducer, devices of the present invention are effective in transmitting ultrasound waves generated by the ultrasound transducer and propagating those waves through an acoustic waveguide into;the oral cavity and the dental fluid to achieve improved plaque disruption and removal, as well as biofilm reduction. Devices of the present invention employing an ultrasound transducer operating in accordance with the parameters described herein in combination with a sonic component are also effective in facilitating bubbly fluid flow and transmitting ultrasound to produce cleaning effects at and beyond the bristles, e.g., from about 0.5 mm to about 7 mm beyond the bristle tips, more typically at least about 1 mm and up to about 5 mm beyond the bristle tips.

[0029] Oscillation of bristle tufts and an acoustic waveguide at sonic frequencies generates bubbly flow and improves cleaning, even absent the action of an ultrasound transducer and transmission of acoustic energy through the acoustic waveguide at ultrasound frequencies. It is, however, the combination of the ultrasonic transducer, acoustic waveguide, and sonic component that together achieve the most effective power toothbrush embodiment of the present invention and yield synergistic cleaning effects that are substantially superior to the additive effects of the sonic and ultrasonic components in isolation.

Problems solved by technology

Previous attempts to take advantage of ultrasound acoustic energy in toothbrushes failed to exploit microbubble formation in dental fluid for purposes of facilitating plaque removal, or failed to consider microbubbles and macrobubbles as a potential impediment to ultrasound propagation beyond the bristle tips.

Because conventional toothbrush bristles and bubbly dental fluid can reduce rather than facilitate the propagation of ultrasound waves, the toothbrushes disclosed in these references would not achieve efficient ultrasound wave propagation.

Also, the ultrasound systems in prior art toothbrushes did not take advantage of the specific bubble structure within dental fluid.

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