Clinical Corner: Information on Dental Procedures

Articles

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How to Quickly and Conservatively Restore a Natural Shine after Orthodontic Bracket Removal
SS White Surgical Length Oral Surgery Burs: Atraumatic Removal of Teeth for Maximum Bone Preservation

"How to Quickly and Conservatively Restore a Natural Shine after Orthodontic Bracket Removal"

By Dr. Jan H. Koch (text) and Fenja Felgenhauer (photos and clinical details) 

After the removal of orthodontic brackets, enamel surfaces should have the same appearance as before the treatment. They should be free of composite residues and as shiny and undamaged as possible. These aims will be achieved with a systematic approach: Composite removal with special carbide finishing burs and polishing with well-proven single-step composite polishers.

After the debonding of brackets, composite layers remain on the enamel surface. They vary in thickness, depending on the position of the tooth in the dental arch, the bonding technique selected and the bracket system used. The objective is always an absolutely smooth and shiny enamel surface, which does not differ from the adjacent, untreated surfaces. Enamel losses due to the use of unsuitable rotary burs or polishers should be avoided, because it has been observed that the loss of the hard, superficial enamel layer leads to a higher risk of cariogenic decalcification. (3) Besides, rough surfaces are more prone to plaque formation than smooth surfaces.

Carbide finishing burs have proved most suitable for excess removal and finishing. These instruments treat enamel surfaces more conservatively than diamond burs. Diamond particles perform a grinding action and do not “differentiate” between composite and enamel. Therefore, diamond burs are more aggressive and more likely to damage the enamel layer (1) and, according to our observations, tend to “jam” easily. For the same reason, it is not advisable to use diamond burs for the trimming of composites. (5)

Carbide finishers, by contrast, perform a cutting, rather than grinding, action, i.e. they remove material in the form of chips. The hardened metal blades act by means of plastic deformation processes and deformation-associated shear forces occurring between blades and surface. (1) This method produces smoother surfaces, as compared to the use of diamond finishers. Incidentally, that is why specialists in all-ceramic restorations recommend using carbide finishers to smooth preparations made with diamonds.

However, there is a large variety of carbide finishers. Working parts with non-rounded transitions may damage the enamel surface. (4) This applies to burs with non-rounded flat ends and burs with pointed cutting tips alike. The optimal instruments are carbide finishers with non-cutting tips and rounded transitions between tip and cutting blades. The latter principle also helps to protect soft tissues when excess material has to be removed from areas close to the gingival margin.

The Safe End finishing burs (SS White Burs, Lakewood, NJ USA, www.sswhiteburs.com) are a good example of instruments designed to meet these requirements (Case Report, Fig. 4, 5, 8, 9). The burs were originally developed for the trimming and finishing of composite fillings. Thanks to various beneficial properties, however, they are also highly suitable for excess removal (10-bladed version) and finishing (20-bladed version) after bracket removal. The blades selectively remove the composite residues, ensuring maximum conservation of the enamel surface (Case Report, Fig. 10).

Figure 1 The result of a short-term multi-band treatment in a 24-year-old female patient. Crowded maxillary anterior teeth were corrected for esthetic reasons. The treatment time was 5.5 months, and a fixed retainer was applied after band removal (Photos, Fig. 1-11: Fenja Felgenhauer, dentist in Hannover, Germany).

Figure 2 The thickness of the bonding composite layer is clearly visible after bracket removal.

Figure 3 This 10-bladed carbide finishing bur (Safe End SE6-10, SS White Burs) is best suited for efficient bulk removal of composite residues. It is used at approx. 40,000 rpm, and with abundant spray cooling.

Figure 4 After bulk removal of residues, the shiny surface typically produced by carbide finishers is already visible.

Figure 5 Most of the residues have now been removed from the central incisors. The burs selectively remove the composite and conserve the enamel.

Figure 6 The 20-bladed Safe End burs are optimally suited for the removal of the remaining composite material and the pretreatment of the enamel surface for polishing.

Figure 7 The 20-bladed version, with its fine dentate design, should be used at a speed of approx. 20,000 rpm, and also with abundant spray cooling.

Figure 8 The result already comes very close to the natural shine desired (see mandibular teeth).

Figure 9 The natural curvature of the labial surfaces is visible from the incisal aspect, and virtually all the composite residues have been removed, without any discernible losses of enamel.

For optimal efficiency, the burs are available in various lengths, depending on the type of tooth and the length of the area to be treated. The slender instrument shape is ideal for the treatment of transitions from composite to enamel surfaces. Besides, the burs accurately remove excess material from areas close to the gingival margin. Additional advantages of the Safe End burs include a long service life and the fact that the flutes are easy to clean, thanks to the straight blade design.

Carbide finishing burs should not rotate at very high speeds. Firstly, because this ensures a longer life, and secondly, because a dangerous 10°C increase in pulp temperature was measured when instruments with a small number of blades (i.e. 6 blades) were used at 150,000 rpm. (2) The 10-bladed Safe End burs should thus be used at approx. 40,000 to 80,000 rpm, and with maximum water cooling. It is advisable to use an electric handpiece, to ensure optimal tactile control, and work intermittently, to avoid excessive heat generation. To prevent the bur from producing grooves, almost no pressure should be applied. The recommended working time is 20 to 30 seconds per tooth.

The 20-bladed version should be used at 10,000 to 20,000 rpm, and also with abundant spray cooling. Since the smoothing effect and the composite removal are immediately visible, a working time of only 10 to 20 seconds per tooth is sufficient. Finally, the teeth are dried and checked for remaining composite residues. If there still are any, they should be removed at very low speeds and with air cooling. To reliably avoid any losses of tooth structure, excess removal and finishing should be carried out only by a dentist or an orthodontist.

The polishing can be done by assistants. Unfortunately, there is a confusing variety of polishing systems, including polishing discs with various grits, silicone polishers used with or without pastes, ceramic polishers, polishing brushes and diamond-impregnated felt discs. After bracket removal, however, complicated multi-step procedures are rather undesirable. So it is ideal that the 20-bladed carbide finishing burs already leave a very smooth surface ready for polishing (Case Report, Fig. 10).

Polishing discs coated with fine aluminum oxide particles are frequently used for the final polishing step. Surprisingly, however, these discs do not necessarily produce a better surface profile than carbide or diamond finishers, even if several grits are used successively. (1) The variations in average roughness, maximum roughness, and maximum distance between indentations and prominences do not seem to be significantly improved by the effect of these polishing discs.

Another study shows that the loss of material caused by the use of polishing discs on decalcified enamel (white spot lesions) is almost three times as high as the loss caused by carbide finishers (0.17 mm3 vs. 0.06 mm3). (6) However, according to the investigators, the clinical relevance of this difference is unclear. Interestingly, the researchers also observed that the enamel was usually damaged in the cervical one-third. And, in most cases, composite residues were still found although the teeth had already been checked – even on enamel surfaces that appeared clean on visual inspection.

Figure 10 In the last step, a Jazz Supreme composite polisher (SS White Burs) is used, with reduced spray cooling for better visual control. This single-step system eliminates the need to change instruments (low pressure creates a high shine!).

Figure 11 The final result: The enamel surface is intact, with the exception of only minute grooves, and a natural high-shine polish has been achieved.

Composite polishers easily and conservatively create a high shine in only one step. Fine diamond particles embedded in silicone or rubber produce a uniformly smooth surface, which has a shiny appearance when incident light is reflected. Single-step polishers differ from multi-step polishers in that the amount of material removed can be varied simply by applying more or less pressure. This eliminates the need to change instruments, and the polishing consumes much less time than in the case of multi-step systems.

The combination of Safe End carbide finishing burs with Jazz Supreme polishers (SS White Burs, Lakewood, NJ USA) provides a complete finishing and polishing system for bracket removal. Jazz polishers are available for composites or ceramics, as one, two or three-step systems, and in reusable or single-patient-use versions. Jazz Supreme composite polishers have proved most suitable for enamel surfaces. Their special room-temperature manufacturing process, in which very fine diamond particles are embedded in a flexible rubber matrix, makes them particularly heat-resistant, colorfast and durable.

The manufacturer recommends using Jazz Supreme single-step composite polishers at approx. 8,000 to 15,000 rpm. This speed applies to the use on composites; in the case of enamel, it should be decreased to approx. 5,000 rpm. Apart from speed, another point should be observed: A true high-shine polish will be achieved only if the correct pressure is applied. The contact pressure influences the number of diamond particles exposed, which means that almost no enamel will be removed if only light pressure is used. It is advisable to test the action of these polishers on a cured composite sample.

The debris produced during polishing is best removed by giving the surface a "tender stroke". This final step creates the excellent high-shine polish desired. Polishing pastes are not needed in this technique. Full spray cooling is not necessary, either, since the pressure and speed used are relatively low. The tooth can be intermittently wetted with either spray or water from the spray insert, depending on personal preference. The large flame is usually the most suitable polisher shape, whereas knife-edge polishers may well cause grooves in the enamel surface if used improperly. The recommended working time is approximately 20 seconds per tooth.

The restoration of a shiny enamel surface after bracket removal is an integral part of daily orthodontic practice. Specially designed carbide instruments, preventing any scratches or unnecessary removal of enamel, help to optimally conserve the natural tooth structure in this procedure. And well-proven composite polishers quickly create the natural high-shine polish desired, in a single step and without the use of polishing pastes. The patients can then fully enjoy the result of their orthodontic treatment – teeth which are absolutely intact and properly aligned in the dental arch.  

1. Eliades T, Gioka C, Eliades G, Makou M. Enamel surface roughness following debonding using two resin grinding methods. Eur J Orthod 2004;26:333-338.
2. Jonke E, Manschiebel W, Freudenthaler JW. [In vitro temperature measurement in connection with composite removal]. Stomatologie 2003 Mar;100(1):23-26 (article in German, English abstract)
3. Ogaard B. Oral microbiological changes, long-term enamel alterations due to decalcification and caries prophylactic aspects. In: Brantley WA, Eliades T (eds.). Orthodontic materials: scientific and clinical aspects. Thieme, Stuttgart 2001, pp. 124-139
4. Radlanski RJ. A new carbide finishing bur for bracket debonding. J Orofac Orthop 2001;62:296-304.
5. Rzanny A, Dornbrack M, Welker D, Fachet M. [Optimizing the surface quality of composite materials for different indications]. Dtsch Zahnarztl Z 2003;58:533-537. (article in German, English abstract)
6. Tufekci E, Merrill TE, Pintado MR, Beyer JP, Brantley WA. Enamel loss associated with orthodontic adhesive removal on teeth with white spot lesions: an in vitro study. Am J Orthod Dentofacial Orthop 2004;125:733-739.