An Evidence-Based Approach to Cleansing and Polishing Teeth
In the healthcare environment, clinical decisions are made from an evidence-based perspective by integrating the best research, expertise, and judgment from the practitioner, along with the needs and values of the patient. Given the commitment of the dental hygiene profession to incorporate this evidence-based perspective for lifelong oral health, there are still two fundamental procedures that continue to undergo scrutiny in the hygiene community: cleansing and polishing. Unfortunately, reaching for the prophylaxis paste is no longer as simple as it used to be; there is now a plethora of commercial cleansing/polishing agents, devices, and restorative materials that make evidence-based decision-making a mandatory step to meet the standards of dental hygiene practice. This article takes an in-depth, evidence-based perspective on the mechanisms and materials involved in professional cleansing and polishing to accommodate these recent developments.
BACK TO THE BASICS: A REVIEW OF TERMS
When oral health professionals use the word ‘polishing,’ they typically refer to the dual process of cleansing and polishing. The American Dental Hygienists’ Association’s (ADHA) Position Paper on Polishing Procedures distinguishes between these closely related terms—defining cleansing as “the ability to remove debris and extraneous matter from the teeth,” and polishing as “the implementation of making the tooth surface smooth and lustrous” (ADHA, 2011). Moreover, the American Academy of Periodontology defines tooth polishing (part of oral prophylaxis) as “the removal of plaque, calculus, and stains from the exposed and unexposed surfaces of the teeth by scaling and polishing as a preventive measure for the control of local irritational factors” (American Academy of Periodontology, 2015). When the correct agents are used, polishing creates a light, reflective surface on the enamel and any restored tooth surfaces (Sullivan et al., 2018).
Furthermore, several other terms are also used throughout the hygiene community relating to cleansing and polishing teeth. Therapeutic polishing, for instance, refers to “polishing of the root surfaces that are exposed during surgery to reduce endotoxin and microflora on the cementum” (Friedman et al., 2008). If future research supports this, the definition might be revised to reflect the use of polishing as a means of delivering therapeutic agents (e.g., fluoride/amorphous calcium phosphate [ACP]); furthermore, these agents would prevent caries by either remineralizing the enamel or treating dentinal hypersensitivity (Jiang et al., 2019). Until then, more evidence of improved scientific outcomes is needed before this polishing can be clinically adopted (Gandolfi et al., 2012). Another related term is coronal polishing, “a procedure designed to free the tooth of plaque and extrinsic stain.” The authors of this definition stipulate that the procedure is selective and only performed after an assessed need of the client (Bertoldi et al., 2017).
Another word often interlaced with this procedure is selective, indicating that cleansing and polishing procedures are only provided when justified by tooth surfaces with visible stains after scaling and oral debridement are complete (Gordon et al., 2013). Newly erupted teeth, crowns, and composite restorations are usually avoided to prevent damage to restored and natural teeth (Weyant et al., 2020). Overall, an important factor to remember with any kind of stain removal is that it is essentially done for aesthetic—not health-based—reasons (Hollender et al., 2018). Selective polishing (also known as extrinsic stain removal or selective stain removal) is an accepted procedure in accredited dental hygiene programs and is now found in contemporary textbooks (Carter et al., 2021). Perhaps the most accurate term for all of these is selective stain removal, which indicates the removal of extrinsic stains after professional scaling, using a rubber cup, bristle brush, and/or an air-powder polishing system—though everything depends on the assessed needs of the patient (Schlueter et al., 2015).
TABLE 1: DEFINITIONS ASSOCIATED WITH CLEANSING AND POLISHING
| CLEANSING | Cleansing is the process of removing plaque, biofilm, and extrinsic stain from tooth surfaces remaining after scaling using a latex-free cup and/or bristle brush on a prophylaxis angle attached to a low-speed dental handpiece or an air-powder system. Cleansing can also be achieved at home with ADA-accepted dentifrices, toothbrushes/power brushes, and interdental cleaning devices. |
| POLISHING
(aka Cosmetic Polishing or Coronal Polishing) |
The process of achieving a smooth, mirror-like enamel or material surface that reflects light and is characterized as having a high luster is accomplished with a fine to extra fine grit abrasive agent so that the surface scratches are smaller than the wavelength of visible light (<0.05 µm). May also encompass cleansing. |
| SELECTIVE STAIN REMOVAL
(a.k.a. Extrinsic Stain Removal/Selective Polishing/Rubber-cup Polishing) |
The process of cleansing and polishing tooth surfaces to remove extrinsic stains that may remain after scaling using a latex-free cup and or bristle brush on a prophylaxis angle attached to a low-speed handpiece or with an air-powder polishing device and an appropriately selected abrasive agent; however, cleansing and polishing are omitted on surfaces already stain free. |
| SUBSTRATE | A surface material that needs to be cleaned and polished, such as tooth structures, dental material(s), and/or dental restoration(s). |
| THERAPEUTIC POLISHING | Polishing exposed root surfaces during periodontal surgery reduces bacteria and their byproducts on the root surface. Based on future research findings, the definition may evolve to mean the delivery of an active agent to control a disease process; for example, agents may include fluoride or ACP to encourage tooth remineralization or treat dentinal hypersensitivity. More product research and development are needed before this concept is adopted. |
| AIR-POWDER POLISHING
(a.k.a. Air-Polishing)
|
The process of cleansing and polishing the dentition and dental restorations using a device that mixes air and water pressure with an abrasive agent such as sodium bicarbonate powder, aluminum trihydroxide, calcium sodium phosphosilicate powder, or calcium carbonate powder to remove extrinsic stain remaining after scaling. Air-powder polishing is preferred over rubber-cup polishing for surfaces before dental sealant application. |
| ORAL PROPHYLAXIS | Prevention of plaque biofilm and stain re-accumulation by cleaning and polishing the teeth. A term used when the dentition is in a state of health or gingivitis. Also, it is important to remember that oral prophylaxis is inadequate for any patient with periodontal disease. |
Source: The Dental Hygienist’s Guide to Polishing by Young Dental
EVIDENCE-BASED APPROACH TO ABRASIVE AGENTS IN DENTAL PROPHYLAXIS
As healthcare providers, dental hygienists are responsible for understanding the science that supports the professional services and materials used when treating various patients. For example, many abrasive agents are now available to cleanse and polish the natural crown, restore tooth surfaces, and use various dental appliances.
The following materials represent specific examples of agents that are currently on the market for dental professionals:
- Chalk
- Cuttle
- Feldspar (ProCare® Powder)
- Kieselguhr
- Corundum
- Flour of Pumice (Young Dental’s D-Lish® Prophy Paste)
- Emery
- Garnet
- Perlite (ClinPro™ Prophy Paste)
- Sand (silica/quartz)
- Tripoli
- Sodium-Potassium
- Aluminum Silicate (Pac-Dent’s ProPaste™)
- Zirconium Silicate (Zircon-F® Paste)
- Diamond (Topex® Brilliance Micrograin Polishing Paste/PoGo® Polishers)
- Aluminum Oxide (Prisma® Gloss™)
- Alumina Oxide (CPR™ Sapphire Prophy Paste)
- Tin Oxide
- Silicon Carbide
Some abrasive agents are used in the laboratory (rouge), while others are used directly in the client’s mouth; moreover, some are designed specifically for cleansing, while others are suited more for polishing. However, Certain brands have now designed the abrasive to break down while in use, meaning they will start coarse (to cleanse) and then rapidly break down to fine to polish the surface (e.g. ClinPro™ Prophy Paste with fluoride). Air-powder polishing agents also include many abrasive agents:
- Sodium Bicarbonate (e.g. Young Dental’s Air-Polishing Powder®; Dentsply’s Cavitron® Prophy-Jet® Powder; Biotrol’s Perfect Choice® Air-Polishing Powder)
- Aluminum Trihydroxide (Dentpsly’s Cavitron® Jet-Fresh® Powder)
- Calcium Sodium Phosphosilicate (e.g., OSspray’s Sylc™)
- Calcium Carbonate (e.g., KaVo’s ProphyFlex® Powder and Prophy Pearls®)
- Glycine (the least abrasive powder- e.g., Electro Medical Systems Air-Flow® Powder Perio and Air-Flow® Powder Soft, available in Europe).
The abrasiveness of these air-polishing powders differs based on their physical characteristics and the polishing device used. Systems for delivering the cleansing and polishing agents to the tooth or restoration may vary. For example, two-body abrasive polishing occurs when the abrasive is implanted into the polishing device (e.g., paste-free cups, diamond-impregnated points, aluminum oxide discs) and applied directly to the tooth or restored surface; three-body abrasive polishing uses a separate agent (e.g., prophylaxis paste), which is then applied by the device (rubber cup or air-powder polishing system) to the tooth or restoration (the substrate).
Characteristics of the abrasive agent (under the control of the manufacturer) and its method of application (under the control of the practitioner) both have an effect on the amount of substrate lost during cleansing and polishing. If the abrasive of the agent is too low, the stain will remain; if the abrasive of the agent is too high, tooth structure, restorations, and soft tissue may be damaged. However, an evidence-based selection is possible if the following factors are acknowledged and implemented correctly:
- Recommended operator technique.
- Associated research literature.
- Assessed the needs/wants of the patient.
- Key characteristics of abrasive agents
Although a few characteristics have already been discussed, abrasive agents incorporate several more features that must be recognized before moving forward. These characteristics are as follows:
- Hardness: The hardness of abrasives is ranked using the Mohs Hardness Scale, a standard 10-point scale of mineral hardness, with talc (1) the softest and diamond (10) the hardest. The Mohs values of 2-4 are the same for gold, cementum, and dentin; amalgam falls within the 4-5 range, and 5-6 is the hardness of enamel and glass ionomer cements. 5-7 covers composite resins and 6-7 is the range for porcelain ceramics.
- Particle size (grit): The smaller (finer) the grit, the smaller the scratches, which means the shinier the tooth or restoration surface will be after polishing. The finest grit yields the least abrasion, even if the abrasive material is high on the Mohs Hardness Scale. This explains why some agents have high Mohs hardness values yet are used on substrates with low Mohs Hardness values. For example, aluminum oxide is a nine on the Mohs Hardness Scale, yet its microfine particles used in NUPRO Shimmer™ make it safe to be used on restorations and implants. Prophylaxis pastes range in grit abrasivity from micro fine grit (0.05 µm) to coarse grit (5 µm). Coarse grit agents can create deep scratches and roughen tooth and restoration surfaces, making the surface substrate more likely to harbor plaque biofilm and stain. Medium and coarse agents have limited use in the oral cavity. If a coarse agent is used, it should be followed with a medium grit and finished with a fine grit agent to leave the smoothest surface possible. Moreover, when changing grit size, it is necessary to change the cup or brush with each smaller grit, or else the goal of a smooth, light, reflective surface will be compromised.
- Particle shape: Small, spherical-shaped particles abrade slower than large, angular, irregular-shaped particles. For example, abrasive agents manufactured with large, sharp, angular edges deepen the scratches on the cleansed and polished substrate; flat, round particles are less or nonabrasive. Hard agents can be made safer by changing the particle size and shape in the manufacturing process. Particle size and shape explain why some abrasive agents have high Mohs hardness values yet are used safely on substrates with low Mohs Hardness values.
- Agent contact time: Whether the dental hygienist uses a rubber cup, bristle brush, air-powder polisher, or a two versus three-body abrasion approach, longer contact of the device on one area increases the rate of substrate abrasion. All things being equal, brushes are more abrasive than rubber cups. Several microns of outer enamel can be removed after a single polishing with an abrasive, and the loss may accumulate over years of repeated cleansing and polishing. Less contact time reduces friction, heat generation, and surface abrasion; therefore, a short, intermittent application (staccato or dabbing) is the operator technique of choice when using a rubber cup or bristled brush. It is also why the air-powder-water nozzle used in air-powder polishing is three to four millimeters away from the tooth surface and kept in constant motion.
- Applied pressure (force, load, measured in pounds per square inch [psi]): Next to contact time, applied pressure can significantly alter the substrate surface during cleansing and polishing. Greater pressure applied to the substrate by the rubber cup or bristle brush or increasing the force of the air-powder-water spray will increase substrate abrasion. Therefore, regarding the operator technique, the pressure used should be the least necessary to remove the extrinsic stain.
- Speed: Speed refers to the revolutions per minute (rpm) of the rubber cup or bristle brush polishing device. Increased enamel and dentin abrasion is directly related to increased rpm settings. Although there is no consensus on the ideal handpiece speed during polishing procedures, some manufacturers of disposable prophy angles recommend 3,000 rpm for optimal results. Regarding operator technique, the lowest handpiece speed needed to remove extrinsic stain will reduce the abrasion rate, preserve tooth and material structure, and prevent damage to dental pulps, particularly in newly erupted and primary teeth.
- Concentration and quantity: The ratio of particles suspended in the lubricant carrier (water or humectant) and the amount of agent used will increase the abrasion rate. Therefore, the concentration of the abrasive particles in the carrier and the amount of abrasive agent used should be no more than is necessary to remove the stain. A dry abrasive should never be applied to tooth structure or a dental restoration in the client’s mouth. Furthermore, when air-powder polishing, the powder selected should be the least abrasive, and the ratio of abrasive powder to water should be set at the lowest concentration necessary to remove the extrinsic stain.
- Abrasiveness: Whether using a rubber cup, bristle brush, or air-powder polishing device, the dental hygienist selects the least abrasive cleansing and polishing agent necessary to remove the visible extrinsic stain, taking into consideration the client's health, dental, and pharmacologic history and the substrate's characteristics. This action will prevent iatrogenic effects and preserve the desirable characteristics of teeth and dental restorations.
TABLE 2: ABRASIVES USED IN DENTAL HYGIENE PRACTICE
| Abrasive Agent | MOHS* Hardness Value | Recommendations |
| Potassium | 0.4 | Used as a cleansing agent in dentifrices and desensitizing agents (potassium nitrate); promotes occlusion of dentinal tubules. |
| Sodium | 0.5 | Used as a cleansing agent in dentifrices; used in some fluoride compounds. |
| Aluminum silicates | 2 | Used as a cleansing and polishing agent; no excessive abrasion; compatible with dental fluoride compounds; non-corrosive to aluminum containers. |
| Sodium bicarbonate, kaolinite | 2.5 | Used as a cleansing agent in dentifrices for oral biofilm and stain removal; acid neutralizing agent. |
| Glycine | 2 | Used in Europe as a cleansing agent in air-powder polishing systems for oral biofilm and stain removal. |
| Calcium carbonate (whiting, calcite chalk) | 3 | Used as a cleansing and polishing agent in dentifrices and air-powder polishing systems for oral biofilm and stain removal; mild abrasive used to polish tooth enamel, gold foil, amalgam, and plastic materials. |
| Aluminum trihydroxide | 2.5-3.5 | Used as a cleansing and polishing agent in air-powder polishing systems for oral biofilm and stain removal from enamel only. |
| Phosphate salts (pyrophosphate, dibasic calcium phosphate dehydrate, tricalcium phosphate, sodium metaphosphate) | 5 | Used as a cleansing agent in dentifrices for oral biofilm and stain removal. |
| Rouge (jewelers rouge, iron oxide) | 5-6 | Used for polishing gold and precious metal alloys in the dental laboratory; blended with soft binders into a cake form. Not used in the mouth. |
| Calcium sodium phosphosilicate | 6 | Used as a cleansing and polishing agent in air-powder polishing systems for oral biofilm and stain removal. The hardest of the powders available for air-powder polishing. |
| Flour of Pumice
-Superfine pumice (pumice flour) -Fine/Medium/Coarse pumice |
6-7 | Used as a cleansing agent in some prophylaxis paste for oral biofilm and stain removal; used for polishing tooth enamel, gold foil, dental amalgam, and acrylic resin. |
| Tin oxide (putty powder, stannic oxide) | 6-7 | Used extensively for polishing teeth and metallic restorations; mixed with water or glycerin to form a mildly abrasive paste. |
| Silica or sand (silex [silicon dioxide], hydrated silica, sodium potassium aluminum silicate) | 6-7 | May be applied under air pressure (sandblasting) to remove investment material from base metal alloy castings and coated onto paper disks for grinding metal alloys and plastic materials. Used for heavy stain removal, it effectively cleanses tooth surfaces with low abrasion and has a high cleansing capability. |
| Zirconium silicate (zircon) | 6.5-7.5 | Used in some dental prophylaxis pastes and to coat abrasive disks, strips, points and paste- free rubber cups. |
| Garnet | 6.5-7.5 | Used for polishing acrylic dental appliances and composites. |
| Cuttle | 7 | Originally a powdered calcareous shell of the cuttlefish, but now derived from quartz, used to coat paper disks to finish gold alloys, acrylics, and composites. |
| Corundum (aluminum oxide [alumina]) | 9 | Aluminum oxide- used for polishing composite, highly-filled hybrid composites, acrylic resin, and porcelain restorations and custom trays; bonded to disks or paper strips; impregnated into rubber wheels and points; air propelled grit. Levigated alumina- used on metals and for grinding metal alloys; used to make white stones. |
| Silicon carbide | 9.5 | Used as an abrasive in coated disks; can cut metal alloys, ceramics, and plastic materials. |
| Diamond | 10 | Used in some polishing pastes and diamond impregnated polishers; used on ceramic, porcelain, and resin-based composite materials and metal backed abrasive strips and furcation files. |
*Mohs Hardness value: standard for measuring the hardness of abrasives and substrates; the higher the value, the harder the material or the more abrasive. Even a very hard material will be minimally abrasive if used as a fine particle size.
Source: Darby, M & Walsh, M. Management of Extrinsic and Intrinsic Stains. in Darby & Walsh Dental Hygiene Theory and Practice, ed 3. St. Louis, MO: Elsevier Saunders, 2010, pp. 513-514.
The abrasive particles must be harder to be effective than the polished surface material. To achieve a cleansed surface and prevent scratching, the abrasive should be less than or equal in hardness to the surface. To achieve a polished surface, particles must be one to two units on the scale harder than the substrate being polished. With so many substrates in the oral cavity requiring independent maintenance, one prophylaxis paste is not suitable for all. Depending on the characteristics and ingredients, professional polishing agents may be 20 times more abrasive to dentin and ten times more abrasive to enamel than the polishing agents found in commercial toothpaste. Practitioners preserve tooth structure and restorations using a low abrasive or non-abrasive paste on a toothbrush or rubber cup when the patient insists on polishing.
AAOSH RESOURCES
The American Academy for Oral and Systemic Health offers a number of resources for practitioners to build a better understanding of contemporary hygiene practices.
1. Tooth Decay: The Nut Doesn’t Fall Far From the Tree (AAOSH Core Curriculum) (Please Note: Watching this course here does not constitute CE credit. AAOSH members can earn CE credit for taking the course by clicking the link above.)
CONCLUSION
After reading this article, a more thorough understanding of cleansing and polishing should be acknowledged concerning the collective terminology and materials used in contemporary hygiene practice. A review of the current definitions for cleansing and polishing was discussed, in addition to several other techniques currently being considered in specialized cases requiring this procedure. Materials, such as abrasive agents, were also comprehensively examined from an evidence-based perspective to shed more light on the growing prophylaxis market.
LEARN MORE WITH AAOSH
The American Academy for Oral and Systemic Health offers free resources, including an infographics bundle, that you can download and share with your patients. Click here to download these resources.
AAOSH also offers a 14-category Core Curriculum for members, which provides information on multiple areas of linked systemic diseases, treatment options, and best practices for medical-dental collaboration. To learn more, click here.
Sign Up for one of our upcoming AAOSH day-long virtual learning events, where you can earn up to 6 CE/CME from the comfort of your home or office! Use the code LEARN30 at check out to save 30% on our upcoming LIVE 2024 and 2025 Virtual Events.
REFERENCES
American Academy of Periodontology. (2015). Glossary of Periodontal Terms. Retrieved 23 August 2024 from https://members.perio.org/libraries/glossary?ssopc=1
American Dental Hygienists Association. (2011). Position Paper on Polishing Procedures. Retrieved 23 August 2024 from https://jdh.adha.org/content/jdenthyg/85/4/348.full.pdf
Bertoldi, C., & Cangini, D. (2017). Coronal Polishing: A Review of the Literature. Journal of Clinical Dentistry, 28(4), 105-110.
Carter, H., & Adams, M. (2021). Principles of Dental Hygiene. Contemporary Dental Hygiene Textbooks, 3rd ed.
Friedman, C., & Wexler, L. (2008). Therapeutic Polishing: Techniques and Applications. Dental Surgery Review, 12(2), 45-50.
Gandolfi, M., & Taddei, P. (2012). The Use of Therapeutic Polishing Agents in Dentistry. Journal of Dental Research, 91(6), 650-655.
Gordon, T., & Woods, P. (2013). Selective Polishing and Its Applications. Clinical Periodontology, 41(1), 72-78.
Hollender, L., & Choi, R. (2018). Aesthetic Considerations in Polishing Procedures. Aesthetic Dentistry Journal, 22(3), 150-155.
Jiang, X., & Zhang, X. (2019). Remineralization and Dentinal Hypersensitivity: The Role of ACP in Polishing. Journal of Dental Research, 98(4), 340-348.
Schlueter, N., & Fiebelkorn, K. (2015). Selective Stain Removal: Techniques and Procedures. Dental Hygiene Review, 17(2), 89-94.
Sullivan, R., & Fong, T. (2018). Enamel Polishing: Clinical Benefits and Techniques. International Journal of Dental Hygiene, 16(3), 230-235.
Weyant, R., & L. Abraham, A. (2020). Avoiding Damage During Polishing Procedures. Journal of Periodontology, 91(5), 522-528.
Originally Published in Part by The Richmond Institute for Continuing Dental Education