A Clinical Comparison of the Gingivitis Reduction and Plaque - removal 37 Efficacy of a New Manual

A cross-functional team was assembled to take on the project of developing a toothbrush that could deliver a “whole mouth clean.” As such, this brush needed to not only demonstrate superior plaque removal from teeth, it also needed to provide a means for safe cleaning of soft oral tissues. During use, the brush needed to be comfortable both in hand and in mouth, and it required contemporary esthetics to help drive consumer acceptance. This article will take the reader through the full development cycle of the new toothbrush, identifying the proposed benefit of each brush feature along the way. Where appropriate, care was taken to identify the specific insights leading to the development of several new features not previously seen in commercial toothbrushes. This article also will attempt to demonstrate the value of forming new product development teams with representatives of multiple functional areas, including marketing, product development, advanced technology, clinical, engineering, and manufacturing. 7 Vol. 25, No. 10 (Suppl 2) Compendium / October 2004 clinical efficacy of the toothbrush, it does impact rather significantly on the comfort and resulting compliance of the brushing experience. The angled offset design and the offset design (Figure 2) have excellent ergonomics by maintaining the point-of-bristle contact in line with the longitudinal axis of the handle during toothbrushing. This prevents the handle from becoming unstable as forces are applied to the head. Initial Research: Soft Tissue Cleaning The next area requiring research was soft tissue cleaning. Cleaning the gingival margin has been a subject of previous toothbrush design research by Volpenhein and Hartman. Toothbrush features that address the cleaning of this area include extended tufts of bristles along the sides of the brush head. Seeking to broaden the efficacy of this product, the team also researched the state of the art of cleaning other major oral soft tissues—the tongue and the cheeks. Rosenberg and McCulloch reported on the benefits of tongue cleaning in the control of bad breath. The primary methods of tongue cleaning used by the general population include tongue scraping and tongue brushing. The function of both is to mechanically remove the biofilm that develops on the surface of the tongue. Research by Yaegaki and Sanada supported findings that the tongue coating is comprised of desquamated epithelial cells, blood cells, and bacteria. A very interesting hypothesis was put forth that removing these epithelial cells from the mouth by cleaning the cheeks could help minimize the number of dead cells available to settle on the tongue, thus minimizing the food source for a host of odor-causing bacteria. Initial Research: Materials and Manufacturing In addition to reviewing the hygienic and ergonomic aspects of toothbrush design, the team also conducted a review of the latest material and manufacturing trends to be sure that it was armed with the latest opportunities these critical areas had to offer. Of particular interest were “anchorless” manufacturing technologies that could allow unique bristle-tuft shapes, unlike conventional brush-making technology, which, for all practical purposes, is limited to uniformly sized bristle tufts. Another benefit of anchorless technology is its ability to produce thinner brush heads, thereby potentially offering a lower-profile brush head for improved oral access. A material trend noted by the development team was the availability of soft, yet highly durable elastomer, which could be molded into nearly any shape for novel toothbrush-cleaning features. These synthetic materials did not contain latex, and they had been approved for many medical applications. Initial Research: Summary Armed with the general knowledge and insights gained through the initial research stage, a design brief was generated with specific guidelines as follows: Brush Head 1. Explore cleaning features based on the functionality of dental prophy cups for improved broadsurface cleaning and surface-stain removal. 2. Include taller outer tufts of bristles for gingivalmargin and interproximal cleaning. 3. Include a raised tip for improved cleaning behind posterior teeth as well as the lingual surfaces of teeth. 4. Explore soft tissue cleaning features (tongue and cheeks). 5. Explore all of the above with the expanded design opportunities offered by state-of-the-art toothbrush manufacturing processes and materials. Figure 1—Typical prophy cup, noted for its paste-holding characteristics. Figure 2—Four basic types of toothbrush handles. 8 Compendium / October 2004 Vol. 25, No. 10 (Suppl 2) 9 Vol. 25, No. 10 (Suppl 2) Compendium / October 2004 Handle 1. Working within the context of either an offset head or an angled offset head, develop a handle that is comfortable to use. Comfortable is defined as offering ease of maneuverability and control with minimal effort. 2. The design must be esthetically attractive, considering current design trends both within the toothbrush category and beyond. The focus of this article is, as it should be, on the development of the efficacious aspects of this toothbrush. It is, however, worth a brief discussion about one of the less tangible aspects of toothbrush design—product esthetics. This subject has drawn a fair amount of attention in recent years. Vanderbilt quotes the Norwegian Design Council regarding the Jordan Multi Action toothbrush: “its soft contemporary form and topical colors turn what is usually regarded as an annoying duty into a pleasure.” Product esthetics play a large role in consumer perception: Is it a modern design? Is it an object I want to use? While on the surface these perceptions may seem to belong solely in the “commercial” domain, these factors also must be acknowledged for their ability to foster patient compliance. To this end, the development team sought the assistance of an external industrial design partner. A particular interest was expressed for a European influence, so a review of potential European design partners ensued. A firm based in Milan convinced the development team they had the ability to digest the team’s insights and experiences and help deliver a leading-edge product. Design Execution: Fulfilling the Brief Working closely with Colgate’s experts, a winning combination of ideas began to emerge. In an effort to evaluate the function of prophy cups, a design emerged with three cups in the center of the bristle field. These cups went through a series of evolutions to achieve the benefits of a prophy cup, while being comfortable to use. The winning combination—developed through a series of three-dimensional computer-aided design models, physical models, and working prototypes— was a soft elastomer ring surrounding a round tuft of bristles (Figure 3). It was hypothesized that this ring would help to retain dentifrice in and around these central tufts, making them more effective at broad tooth-surface cleaning and surface-stain removal, similar to its inspiration, the prophy cup. It was discovered during the prototype stage that the comfort of the configuration was significantly increased by slitting these rings into four arcs, providing greater flexibility to adapt to nonplanar tooth surfaces and improving the manufacturability of the design. A further prophycup–inspired enhancement was added to the central cup. A pair of long, arc-shaped tufts of bristles was added to help surround the center cup to aid in maintaining the presence of dentifrice. These long, continuous walls of bristles would be achieved easily with the aforementioned anchorless tufting technology. Another key benefit of this new brush-making technology was its ability to consistently deliver high-quality bristle-end Figure 3—Close-up of three polishing cups at the center of the toothbrush head. Figure 4—Side view of the pointed outer tufts. Previous research has indicated that regardless of the design of toothbrush people use, their brushing technique will remain basically unchanged and sorely inadequate. The task, therefore, was to design an effective plaque-removing toothbrush with a bristle configuration that could adapt to any brushing style.