Marked extrinsic staining following microabrasion: a case report of a boy with dental fluorosis

Case report

A 12-year-old boy attended the Department of Paediatric Dentistry for assessment of his discoloured teeth. He was fit and well. He did not like the appearance of his front teeth and, for that reason, he rarely smiled. He was born and raised in Iran before moving to the UK at 10 years of age. His sister, who was 13 years old, also had the same condition.

Clinical examination revealed that his oral hygiene was good and there was no caries. It was noted that he had generalized, symmetrical mottling of the enamel affecting all his permanent teeth. The maxillary central incisors also had significant brown discoloration towards the incisal edges (Figure 1). The clinical appearance, together with the history of his first 10 years spent in an area of water fluoridation, indicated a diagnosis of dental fluorosis.

After discussion with his parents, it was agreed to carry out microabrasion of the maxillary central incisors and then, if needed, vital bleaching. The patient attended a few days later for the initial treatment of microabrasion. This was carried out on the labial aspect of the maxillary central incisors under rubber dam. No local anaesthesia was given thus the rubber dam was secured with Rubber Dam Wedgets® (Coltène) (Figure 2). Using a prophylaxis brush in a slow handpiece and a mixture of pumice and 37% phosphoric acid to create a slurry, the labial surfaces of the incisors were polished. The acid-etch 37% (SDI) and pumice (CR Minerals) mixture was used for 10 seconds, five times followed by washing, drying and polishing with fine Sof-Lex discs (3M). This technique was first described in 1989.¹⁶

Following microabrasion, the brown opacities on the maxillary central incisors became less obvious, but were still visible (Figure 3). On the same day, an alginate impression for a maxillary bleaching tray was obtained in order for the patient to carry out home bleaching.

The patient and the parents were provided with verbal post-operative instructions emphasizing the need to avoid food and drinks with colouring for two days. He was reviewed after one week. Unfortunately, both the father and his son were unhappy when they returned as the microabraded teeth had developed a marked yellow discoloration (Figure 4). On questioning, the young boy stated that he had consumed a drink containing turmeric the same night that he had attended for his treatment of microabrasion. An attempt was made to polish the yellow stains with pumice, however, this failed. Thus, a second course of microabrasion was carried out using the same method as previously described.

Whilst the majority of the yellow staining was removed following a second course of microabrasion, a yellow hue still remained (Figure 5). On the same day, the patient was given a bleaching tray and two tubes of 10% carbamide peroxide gel (Opalescence) with clear instructions on its use. The patient was asked to clean his teeth last thing at night, apply the carbamide peroxide gel to the labial aspect of the bleaching tray and, following insertion of the tray to cover his maxillary teeth, wipe away any excess gel. The tray was worn overnight for 7 nights. In the morning, the tray was removed and cleaned, and the teeth brushed. Instructions were also given for managing sensitivity, however, the patient did not experience any during the treatment. Finally, advice was given on foods to avoid during the treatment, similar to the advice given for the microabrasion.

Follow up

The patient was reviewed after 2 weeks (Figure 6). The brown discolorations had almost completely disappeared and the staining from the turmeric was completely removed. However, on close examination, the teeth appeared ‘cream’ when compared to the opaque white colour of the adjacent and opposing teeth affected by fluorosis. Although this did not concern the patient, others may wish to continue bleaching the affected incisors for a longer period to reduce the contrast further. In a subsequent appointment 2 months later, the appearance of the teeth remained unchanged.

Discussion

The risks of microabrasion are minimal and side-effects rare. The main post-operative instructions following treatment are to avoid foodstuff with colouring for 48 hours. A review of microabrasion techniques in 2015 by Pini et al makes no reference to complications similar to that found in this case report.⁹

Microabrasion has been the technique of choice for managing dental fluorosis for many years. However, as demonstrated in this case, it may have complications if the post-operative instructions are not followed correctly. In recent years, bleaching materials, such as carbamide peroxide and hydrogen peroxide, have been used alone or in conjunction with microabrasion for the management of developmental defects of enamel, such as fluorosis and amelogenesis imperfecta.^{14, 15, 17} The reasons for that are the simplicity of the procedure, the potentially good results observed, and the minimal risk to the dentition. There remains no guidance as to whether microabrasion should be carried out before bleaching or bleaching ahead of microabrasion. This is best decided on an individual basis. It is, however, important to mention the guidelines regarding tooth bleaching for under 18s which, according to the EU regulation (Directive 2011/84 EU), is illegal. The GDC's position, however, is extremely helpful for cases such as that described, given that it states that the use of hydrogen peroxide to treat or prevent disease in individuals with defects of enamel is possible. In this case, bleaching was beneficial in reducing the discoloration of the enamel. The alternative, composite restorations would be very destructive and would not have benefited the patient.

A randomized control trial comparing microabrasion with microabrasion and bleaching for patients with fluorosis found that there was no difference in the outcome between the two techniques.¹⁸ However, they do conclude that the combination of the two techniques is a more effective means of reducing enamel fluorosis staining and observed that patient satisfaction was better when both techniques were used.¹⁸ This case demonstrated that bleaching did manage to remove the brown opacities towards the incisal edges of the maxillary central incisors, which microabrasion did not. This suggests that the combination of the two techniques resulted in a more successful result.

A literature search found only one published paper discussing similar complications following microabrasion for a child with amelogenesis imperfecta. In this case report, tomato sauce was ingested the same day as the microabrasion was performed and the teeth turned yellow.¹⁹ Management of the discoloured teeth was resolved by bleaching with 16% carbamide peroxide alone before placement of composite resin restorations. Apart from this study, there are no other documented cases of extrinsic staining following microabrasion. A study in 2000 found no instances of staining following a four-year follow-up of 18% hydrochloric acid and pumice treatment for the management of enamel discolorations.²⁰ There are, however, studies linking extrinsic staining with vital bleaching, possibly because of its much wider use. There is an increased risk of extrinsic staining following bleaching with carbamide peroxide, which is due to increased surface roughness of the enamel following bleaching, which has been found to facilitate subsurface penetration of colourants.^{21, 22} However, these studies are in vitro. A literature search for clinical reports of discoloration following vital bleaching found no such cases, whereas other complications, such as sensitivity, are common.²³ The changes in enamel structure following microabrasion are fundamentally different from that of bleaching, however, an increase in surface roughness is seen after both treatments.⁹ Additionally, a small amount of enamel is removed by microabrasion which, for 37% phosphoric acid with pumice, can reach 40 μm.¹⁰ Based on that assumption, the post-operative instructions following microabrasion are very similar to those of bleaching. These should include the avoidance of consumption of food and liquids with colourings for a minimum of 48 hours, as well as advising the patient to refrain from smoking for a minimum of 2 hours.

This case raises the question as to whether microabrasion should be the first treatment of choice for dental fluorosis. As seen here, vital bleaching provided a better result, by removing the yellow hue as well as the majority of the brown discoloration.

Conclusion

In the patient discussed, failure to follow post-operative instructions resulted in a complication, which is rarely seen. The consumption of a drink containing turmeric the same day as microabrasion of the maxillary incisors resulted in a yellow discoloration of the treated teeth. In order to resolve the acquired staining, it was necessary to provide a further course of microabrasion in addition to bleaching the teeth. The final result was satisfactory. This case illustrates the importance of post-operative instructions to inform patients of the need to avoid foodstuffs with colourings for at least 48 hours following treatment. Post-operative instructions for such cases should be written and given to both patient and parent, as complications can be avoided by carefully following them. This case also highlights the need for further research to understand how food and drinks with colourings can stain teeth with DDEs following microabrasion.