Dentistry – Apparatus – Having intra-oral dispensing means
Reexamination Certificate
1999-10-22
2001-11-27
Lucchesi, Nicholas D. (Department: 3732)
Dentistry
Apparatus
Having intra-oral dispensing means
C433S006000, C433S215000
Reexamination Certificate
active
06322360
ABSTRACT:
FIELD OF THE INVENTION
The present invention broadly relates to structure and methods for delivering medication to the teeth and/or gingiva of a dental patient. More particularly, the field of the present invention concerns a medication retention assembly for a custom-made oral delivery tray that can be fabricated in a dental laboratory or in the practitioner's office.
DESCRIPTION OF THE RELATED ART
A variety of methods have been proposed in the past to deliver medication to the teeth and/or gingiva (i.e., the gum tissue) of a dental patient. One method of applying medication to teeth involves direct application of the medication to the tooth surface by the use of a brush, swab or the like. This method is relatively inexpensive and can be carried out either by the dental practitioner or by the patient.
Unfortunately, the direct application of a medicant to oral structures is generally unsatisfactory because the medication typically does not remain on the oral structure for a significant length of time. The length of time is variable and may depend on factors such as the viscosity of the medication, the presence of saliva and the ability of the patient to prevent adjacent soft tissues such as inner surfaces of the labia or lips and bucca or cheeks from contacting the tray containing the medication. In many instances, the effectiveness of the medication is substantially diminished if the medication is prematurely removed from the oral structure under treatment.
Another common method for delivering medication to teeth involves the use of a dental tray that is placed over the dental arch. The tray has a channel that receives the teeth and has a length that is sufficient to receive all or at least a portion of the dental arch. In some instances, the channel has a sufficient depth to receive a portion of the gingiva along with the teeth.
Many dental medication delivery trays are mass-produced and not custom made to closely fit the dental arch of a particular patient. Although such trays are relatively inexpensive, they are often considered quite bulky and unpleasant to wear for any significant length of time. Additionally, some mass-produced dental trays do not retain medication against the oral structures under treatment unless the patient remains relatively immobile.
Dental trays that are custom-made to closely fit the dental arch of a patient are considered by many to represent a significant improvement over mass-produced dental trays. The close fit provided by custom-made trays largely avoids unnecessary void spaces that are common with mass-produced dental trays. Most custom-made trays are less obtrusive in the mouth than mass-produced trays, and as such are more comfortable to wear for extended periods of time.
One technique of making a custom dental tray involves taking an alginate impression of a patient's dental structure, and then making a model or casting from the impression. Next, a thin sheet of heat softenable plastic material (such as a thermoplastic material) is placed over the casting and heated, often under vacuum, causing the plastic sheet to drape over the model and ultimately form a configuration that closely matches the shape of the underlying model. The tray is then trimmed as needed.
One of the most common uses of both mass-produced and custom-made dental medication trays is in connection with a bleaching gel or solution to whiten the patient's teeth. Many individuals desire whiter teeth and seek to eliminate or at least reduce the discoloration of stained teeth. Tooth stains are caused by a variety of sources, including food and beverages, drugs (such as tetracycline), tobacco products and poor oral hygiene.
When dental trays are used for bleaching teeth at home, the patient is typically instructed to place an amount of bleaching solution into a corresponding area of the tray for each tooth to be treated. The tray is then placed over the dental arch. Often, the bleaching solution is changed every 0.5 to 2.5 hours and the tray is removed during meals. Sometimes a recommendation is made to wear the dental tray overnight. The efficacy of the bleaching procedure depends on factors such as the type and intensity of the stain, the bleaching agent contact time on the tooth surfaces, the amount of available active ingredient in the bleaching solution as well as patient acceptance and adherence to the procedure.
Unfortunately, the volume of bleaching solution that is available in conventional trays tends to diminish rapidly over time, thereby decreasing the amount of active ingredient available for bleaching the teeth. Test results in the April, 1997 issue of the
Clinical Research Associates Newsletter
show that in many instances after 30 minutes, less than 50% of the original quantity of bleaching agent was available for bleaching activity. The same test results show that in many instances after one hour, less than 25% of the bleaching agent was available for bleaching activity. Consequently, it is often recommended to replenish the bleaching agents in conventional trays about every 15 to 30 minutes in order to maintain the most efficacious dosage of bleaching agent in contact with the tooth.
However, the daytime schedules of many patients do not easily accommodate periodic, continuous replenishment of the bleaching agent. In addition, periodically replenishing the bleaching agent during the night is unrealistic for many patients. Since patient adherence to the procedure determines the ultimate success of the treatment program, the need to constantly replenish the dental bleaching solution is a major obstruction that limits the success of the treatment.
An improved custom-made dental tray for delivering medication to oral structure is described in U.S. Pat. No. 6,126,443. The dental tray described in that reference has one or more medication reservoirs that each include a plurality of discreet support members projecting away from the reservoir to engage the dental structure of the patient. The support members are arranged to resist the flow of medication such as bleaching solution in a gingival direction so that retention of the solution in the tray is enhanced.
In certain embodiments of the custom-made dental tray described in U.S. Pat. No. 6,126,443, the reservoirs are made by placing one or more substrates over a mold, casting or other model of the patient's dental structure, and then forming a sheet member over the substrate(s) and the model to provide a custom-molded structure. The substrate(s) in preferred embodiments include a backing layer with a number of spaced apart protrusions extending from the backing layer in a direction toward the model. Once the tray is completed, removed from the model and placed in the oral cavity of the patient, the protrusions extend toward the patient's dental structure that is intended to receive the medication. The protrusions serve as the discreet support members mentioned above to facilitate retention of the medication (such as dental bleaching solution) in the tray.
In certain embodiments of the medication delivery tray described in U.S. Pat. No. 6,126,443, the substrate is elongated and of a size sufficient to extend over several model teeth. As a result, application of reservoir-making material to the surface of each model tooth on an individual basis can be avoided and the total time required to make the tray is substantially reduced. The tray is preferably made with the elongated substrate permanently bonded to the thermoplastic tray material, although as an alternative the substrate may be placed over the model teeth with its protrusions facing outwardly such that an impression of the substrate is formed in the thermoplastic material to create the discreet support members mentioned above.
The elongated substrate that is described in U.S. Pat. No. 6,126,443, is optionally supplied to the practitioner in an assembly (known as a dental medication retention assembly) that also includes a section of double-sided adhesive tape (i.e., a section of tape with adhesive on both sides) and a release li
3M Innovative Properties Company
James D. Christoff
Lucchesi Nicholas D.
LandOfFree
Medication retention assembly for oral delivery tray does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Medication retention assembly for oral delivery tray, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Medication retention assembly for oral delivery tray will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2577368