Treatment options for deciduous molar hypomineralization: a report of three cases

Case reports

Three paediatric patients diagnosed with DMH were treated at the IPS CES Sabaneta Clinic (Colombia). The biological parents provided signed informed consent, and were administered a structured questionnaire¹² addressing issues of pregnancy and the child's early life (Table 1). For each case, treatment was designed taking into consideration age, disease severity, family's socio-economic conditions, patient's behaviour and parents' expectations. Clinical assessment was performed with artificial light, and complementary diagnostic aids if required.

Case 1

A 4-year-old male patient presented to the paediatric dentistry clinic because his parents were concerned about white spots on his teeth. Dental examination revealed hypomineralization in the upper and lower deciduous molars and canines, characteristic of mild DMH (Figure 1). URE had a fractured vestibular surface with slight enamel loss that could be cleaned easily, avoiding accumulation of dental biofilm, and without compromising tooth function or sensitivity. Therefore, this case was classified as mild HMD.

A non-surgical treatment focusing on control of risk factors, such as consumption of carbohydrates and brushing with 1,450 ppm fluoridated toothpaste, was implemented. In addition, dental prophylaxis with rubber cup and prophylactic paste (Proquident, Envigado, Colombia), as well as application of fluoride varnish (Duraphat^® Colgate, New York, USA), were part of this patient's treatment plan; the application of fluoride was carried out as a risk control measure for dental caries.¹³ Screening was performed every three months. At the first control appointment, no enamel fracture was observed in the affected tooth.

Case 2

A 4-year-old male patient, presenting negative behaviour, active nail and solid structure biting habits, loss of tooth structure in teeth URE, LLE and LRE, and with dentinal sensitivity, was diagnosed with severe DMH in deciduous molars and canines (Figures 2a, b).

For this patient, treatment was aimed at preserving his dental structure, relieving symptoms, and improving his behaviour. Initially, a non-surgical treatment, as described for Case 1, was implemented (Figures 2a, b). Teeth with loss of dental structure (URE, LLE, and LRE) were temporarily restored (Figures 2c, d) with nano-filled, resin-modified, glass nanoionomer cement (Ketac™ N100, 3M ESPE, New York, USA) following manufacturer's instructions.

During the follow-up period, while temporary restorations of teeth URE, LLE, and LRE were found fractured at every visit, there was no compromise of the remaining dental structure. Additionally, the parents were informed that the dental sensitivity had significantly decreased. After six months of follow-up, his symptoms had improved and the remaining dental structure was intact.

Case 3

A 5-year-old female patient was brought to our dental clinic with her parents complaining that she had a ‘really ugly tooth, the filling is always falling off, it hurts, and it's breaking’. The parents and the patient attended the consultation requesting a treatment with durability and high aesthetics. The patient had a dental history of pulpotomy on tooth LLE (Figure 3b). The patient complained of hypersensitivity and that it was difficult to brush teeth and eat. Nonetheless, she presented with positive behaviour. Based on clinical and radiological findings (Figure 3e, 3f), this patient was diagnosed with severe DMH (Figure 3a–d).

For this patient, an initial non-surgical preventive treatment for teeth without dental structure loss was implemented, as described for the previous cases (Figures 3a, b). Teeth ULE and LRE presented moderate enamel loss that was restored with glass ionomer cement (Ketac™ Molar Easymix, 3M ESPE, New York, USA), as described by Fragelli et al.¹⁴ As shown in Figure 4a, a zirconia dental crown (NuSmile^®, Houston, USA) was used on tooth LLE. Topical anaesthesia (Garhocaína^®, Bogotá, Colombia) was applied for 2 minutes on the buccal mucosa sulcus, and local anaesthetic using lidocaine with 2% epinephrine (New Stetic^®, Antioquia, Colombia). Subsequently, the crown was prepared with a high-speed diamond bur (Jota^®, Switzerland) by initially grinding 0.5 mm from the buccal and lingual cusps, followed by 0.5 mm deep buccal and lingual cuts, and proximal surface reduction of 1.5 mm performed with a black line diamond bur.

Scuffs were levelled and occlusal fit was verified by performing the pink pigment test (Figure 4c). The shoulder of the finish line was removed with a green-line diamond bur, extending the preparation to the sub-gingival level in a knife-edge configuration. Next, the crown was cemented with resin-modified glass ionomer cement (RelyXTM Luting 3M^®, Sao Paulo, Brazil) following manufacturer's instructions (Figure 4d).

At 6-month (Figure 4) and 1-year (Figure 5) clinical and radiological follow-up, the crown on LLE showed proper adaptation, periodontal integrity, and no changes in structure or colour. Furthermore, no alterations were observed in antagonist teeth. The distal surface of LLD (Figure 4h) showed progression of dental caries without surface cavitation, so that education measures were increased. During the one-year follow-up, the eruption of the lower left first permanent molar with white opacity without loss of tooth structure was observed (Figures 5a–c). On the distal occlusal surface of LLD, progression of dental caries was found, with cavitation of the surface; this was restored with adhesive material and habits of diet and toothbrushing were reinforced.

Discussion

Hypomineralization is a condition that may lead to clinical, functional and aesthetic discomfort, as well as to a greater need for dental treatment, particularly in severe cases. The prevalence DMH ranges from 4.6%¹⁵ to 21.8%.¹⁶ Currently, there are no clinical guidelines describing treatment options for DMH, making its treatment challenging for the general and paediatric dentist, and possibly leading to under- or over-treatment of teeth affected by DMH.

Treatment of hypomineralization of deciduous and permanent teeth is a clinical challenge. In addition to taking into account severity, symptoms, dental age, cost-benefit, and patients' expectations,³ choice of treatment must also consider patients' behaviour. Furthermore, the majority of research on hypomineralization treatment options is usually done on permanent teeth,¹⁰ and those results have been extrapolated to deciduous teeth.

The recommended guidelines for MIH¹⁰ were applied for the patient presenting with mild DMH (Case 1). Educational measures for parents and patient were prioritized, aiming to motivate and raise awareness of the importance of proper oral hygiene and eating habits. As a complementary measure, 5% fluoride varnish was applied. The use of this product in patients with hypomineralization is intended to increase calcium and fluoride ion release, control hypersensitivity,¹⁷ and control development of dental carious lesions.¹³

For severe DMH cases, implementation of health promotion and sugar control is recommended, together with preventive or minimally invasive restorations through the use of occlusal sealants, glass ionomer cement restoration, resin composites, steel crowns, exodontias, and/or orthodontic treatment.¹⁸ Cases 2 and 3 (Figures 2 and 4) presented deciduous molars with severe lesions. However, three factors determined the final choice of treatment: reason for consultation, patient's and parents' expectations of treatment, and patient behaviour.

For the patient described in Case 2 (severe DMH), nano-filled, resin-modified, glass ionomer cement was used since, in addition to having conventional glass ionomer cement properties, it has been shown to exhibit proper physical and mechanical properties¹⁹ which, in this case, were required given the severity and location of the lesions (Figures 2a and b). In addition, those teeth had a history of unsuccessful restoration using high-viscosity glass ionomer cement, hence the need for an adhesive material. The restoration with glass ionomer cement was made temporarily for the purpose of preserving the molar²⁰ while seeking a more positive patient behavioural response.

The patient described in Case 3, with severe DMH on tooth LLE, presented with pain, loss of structure, recurrent failure of adhesive restoration and aesthetic concern was expressed by the parents. In this context, a more invasive approach was taken in order to reduce the number of interventions and to improve aesthetics. Therefore, the treatment included a preformed zirconia crown, which is considered a simple and effective treatment that shows good long-term benefits.²¹ Compared to other commercially available brands, NuSmile^® requires less tooth reduction.²² On the other hand, this technique removes fragile dental tissue, leaving the remaining dental structure in optimal condition. After one year of follow-up, the parents and the patient were satisfied with the treatment and, in addition, periodontal integrity, marginal adaptation, occlusal fit and colour stability were observed during clinical evaluation. Nonetheless, further longitudinal studies are required in order to evaluate this type of treatment, as well as its cost-benefit ratio for DMH treatment.

For molars severely affected by DMH with dental sensitivity, post-eruptive fractures and/or dental caries lesions affecting more than two surfaces, stainless steel crowns are one of the treatment options. The ‘Hall technique’ is a non-invasive approach, in which an appropriately sized steel crown is seated on the tooth by digital pressure and cemented with glass ionomer cement, without prior use of local anaesthesia, tissue removal (carious or hypomineralized) or tooth preparation.²³ Despite the clinical and biological benefits of this method,^{24, 25} and having been offered to parents as the first treatment option of the patients described in Cases 2 and 3, it was not accepted due to unfavourable aesthetics.

For severe MIH cases, in which considerable structure loss is evidenced, exodontia is a treatment option at an ideal age. Elhennawy and colleagues argue that, in these cases, the approach presents an adequate cost-benefit ratio, since preserving teeth with severe defects would increase costs for patients in the long run and it would be more effective to perform an extraction and implement an early orthodontic treatment.¹¹ However, any extraction of a permanent first molar should consider the ideal dental age for this to be performed, which has been recommended between 8.5 and 9 years of age,²⁶ to allow the migration of the second permanent molars in the position of the first permanent molar to establish an ‘acceptable’ occlusion,²⁷ and orthodontic treatment may not be necessary.

For severe cases in deciduous teeth, exodontia may also be a choice of treatment. However, the implications of the premature loss of the second deciduous molar, and the occlusal, skeletal, functional and behavioral consequences should be considered.

Finally, the importance of early diagnosis of DMH and differential diagnosis with other enamel defects and dental caries is emphasized, as well as the need for providing patients and parents with the necessary education and awareness to establish a conservative treatment plan, for which it is necessary to establish clinical guidelines that consider symptoms, severity, cost-benefit ratio and patient behaviour.²⁸

Conclusions