The pros and cons of selective polishing
Many of the techniques and modalities used by dental hygienists have evolved over the years. However, coronal tooth polishing has remained a staple of the dental hygiene appointment, even though its use has been controversial since the 1970s. Patients have come to expect polishing as a necessary part of the dental appointment (Daniel SJ et al, 2008). But world-wide, many dental hygiene schools now recommend selective polishing as standard protocol instead of including polishing at every professional maintenance appointment.
At the turn of the last century, Dr Alfred Civilion Fones began training his female auxiliaries to provide coronal tooth polishing (Peterson SA, 1972). By the 1970s, Esther M Wilkins RDH DMD, author of the widely used textbook. The clinical practice of the dental hygienist, was promoting polishing as a selective process due to its removal of surface enamel (Wilkins EW, 1976). In the 1990s and 2000s, further evidence has supported the adoption of selective polishing (Redford-Badwal DA, 2002; Barnes CM, 2004). However, the concept of full-mouth polishing is still used in many – if not most – dental hygiene practices.
The traditional method of polishing consists of applying a rubber tip with prophy paste to the supragingival enamel surfaces to remove plaque and stain (Wilkins EW, 2009). Some research shows that polishing can remove four micrometres of tooth surface during a 30-second pumice polishing procedure (Wilkins EW, 1976; Vrbic V et al, 1956). With frequent polishings, tooth surfaces may be damaged due to the loss of fluoride-rich enamel surface levels. However, the minerals contained in saliva consistently work to remineralise tooth surfaces (Perry DA, Beemsterboer PL, 2007). The current recommendation is to use a slow-speed handpiece with prophylaxis polishing paste for one to two seconds with a light touch while gently flaring the cup to remove extrinsic stain (Wilkins EW, 2009; Darby ML, Walsh MM, 2003).
After a scaling or debridement, the dental hygienist should evaluate the patient’s enamel surfaces. If no stain exists, polishing may not be necessary. Polishing is needed when extrinsic stains are visible on enamel, cementum, dentine or restorations (Wilkins EW, 2009). Only the necessary crown surfaces should be polished to remove extrinsic stain and dental biofilm (Wilkins EW, 2009). Stain removal is not essential for healthy teeth but is an important aesthetic procedure. Rubber cup polishing is not the only means of removing stain. Hand scaling, sonic and ultrasonic instrumentation, as well as air polishers, also remove stain (Darby ML, Walsh MM, 2003). New pumice-free polishing cups that eliminate the need for polishing paste are also available.
Considerations for prophylaxis pastes
If polishing is indicated, the characteristics of the abrasive particles – including shape, hardness, body strength, attrition resistance and particle size (grit) – should be considered when selecting prophylaxis paste for patients. Each characteristic will determine the effects on the coronal surfaces.
Abrasive agents vary in grade – from fine to coarse – with each designed for a particular use. Superfine grades are available for polishing enamel surfaces and metallic restorations, while laboratory procedures use a coarser grade. The abrasive agent should be chosen based upon frequency of use, e.g. toothpaste for daily use = superfine, prophy paste = less fine for periodic use (Wilkins EW, 2009).
Cleaning agents in polishing pastes differ in shape and hardness and include alkaline and aluminium silicate (Wilkins EW, 2009). Dental hygienists should have a variety of pastes in their armamentarium to accommodate the different tooth surfaces when polishing (Wilkins EW, 2009). Polishing pastes now contain various enhancing additives to perform special functions, such as adding to the mineral surface of enamel (calcium phosphate), adding fluoride, decreasing dentine hypersensitivity, or tooth whitening. Calcium phosphate works to stimulate remineralisation, causing original hydroxyapatite to form a stronger enamel, enhancing tooth smoothness and increasing enamel lustre (Wilkins EW, 2009).
Polishing is not necessary prior to fluoride application, since the uptake of fluoride is not inhibited by plaque biofilm (Wilkins EW, 1976; Wilkins EW, 2009; Perry DA, Beemsterboer PL, 2007).
Three Danish study groups consisting of 160 children each found that topical applications of acidulated phosphate fluoride are effective caries prevention measures and fluoride applications for caries prevention are not impacted by prior prophylaxis (Bijella MF et al, 1985).
A possible contraindication for polishing is that the abrasive pastes may scratch the outer surfaces of materials used for restorations such as composite resin, amalgams and gold restorations (Perry DA, Beemsterboer PL, 2007). Other concerns are bacteraemia and damage to the pulp of the teeth due to the heat generated by a power-driven prophy angle (Perry DA, Beemsterboer PL, 2007).
As dental professionals, we need to begin re-educating our patients on healthy procedures. Firstly, the meaning of selective polishing should be explained, along with the evidence that shows why polishing may not be necessary at every appointment when daily care is effective. Finally, patients should understand that even with the removal of stains and biofilm, acquired pellicle begins reformation within minutes (Wilkins EW, 2009).
Dr Fones stated in 1934: ‘The greatest service [the dental hygienist] can perform is the persistent education of the public in mouth hygiene and the allied branches of general hygiene.’
Coronal polishing should be reviewed with every patient. Do I polish for cosmetics or to make my patient feel good? May I just brush to complete the removal of biofilm?
Use your evidence-based knowledge to determine what is best for each of your patients. In addition, keep in mind that other products used during the polishing procedure may indeed help remineralise tooth surfaces and alleviate sensitivity. New products may change concepts about selective polishing and the jury is still out.
Reproduced with permission from Dimensions of Dental Hygiene. March 2009; 7(3): 32, 35
Barnes CM (2004) Protocol for polishing. Dimensions of Dental Hygiene 2: 26-32
Bijella MF, Bijella VT, Lopes ES, Bastos JR (1985) Comparison of dental prophylaxis and toothbrushing prior to topical APF applications. Community Dent Oral Epidemiol 13: 208-11
Daniel SJ, Harfst SA, Wilder RS (2008) Mosby’s dental hygiene concepts, cases and competencies. 2nd ed. St. Louis: Mosby Elsevier
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Fones AC (1934) Mouth hygiene. 4th Ed. Philadelphia: Lea & Febiger
Perry DA, Beemsterboer PL (2007) Periodontology for the dental hygienist. 3rd Ed. St Louis: Saunders Elsevier
Peterson SA (1972) The dentist and his sssistant. 3rd ed. St Louis: Mosby
Redford-Badwal DA, Nainar SM (2002) Assessment of evidence-based dental prophylaxis education in postdoctoral pediatric dentistry programs. J Dent Educ 66: 1044-1048
Vrbic V, Brudevold F, McCann HG (1956) Acquisition of fluoride by enamel from fluoride pumice paste. J Dent Res 35: 420
Wilkins EW (1976) Clinical practice of the dental hygienist. 4th ed. St Louis: Lea & Febiger
Wilkins EW (2009) Clinical practice of the dental hygienist. 10th ed. St Louis: Lippincott Williams and Wilkins