Deep Resin Infiltration for the conservative management of a Central Incisor affected by MIH

A clinical case by our Community member Dr. Nisha Deshpande

This article and its content are published under the Author’s responsibility as an expression of the Author’s own ideas and practice. Styleitaliano denies any responsibility about the visual and written content of this work.

Molar-incisor hypomineralisation (MIH) was first defined in 2001 by Weerheijm et al. and as “hypomineralisation of systemic origin, presenting as demarcated, qualitative defects of enamel of one to four first permanent molars (…) frequently associated with affected incisors”. In 2003, MIH was described as a developmental, qualitative enamel defect caused by reduced mineralization and inorganic enamel components which leads to enamel discoloration and fractures of the affected teeth. Although the etiology remains unclear, the localized and asymmetrical lesions seem to have a systemic origin. The clinical presentation of MIH depends on its severity and can range from whitecreamy opacities, yellow-brown opacities, post-eruptive enamel breakdown, to atypical caries located on at least one first permanent molar with or without incisor involvement.
Common clinical problems for patients with MIH are:
• Post-eruptive enamel breakdown leading to dentine exposure which increases the risk of pulp involvement
• Tooth Sensitivity
• Aesthetic Problems
• Difficulty in administering local anaesthesia
• Tooth loss
Although resin infiltration has shown good results in mild MIH cases with superficial white lesions, deeper lesions require a modified technique for the aesthetic management of incisors, called “deep resin infiltration technique” (Attal et al.). This technique involves preparation of the affected tooth by macroabrasion, either by intraoral sandblasting or a round bur at low RPM to ensure that the infiltration can indeed reach the full extent of the lesion in case of MIH.

styleitaliano style italiano smile with brown spot on central incisor

A young girl, aged 12 came into our dental office with the chief complaint of the dark brown area on her front tooth. She expressed her embarrassment at school and social situations where she was being teased about the brown spot causing her a lot of despair.

styleitaliano style italiano intraoral picture of MIH lesion

History and examination revealed the presence of brown discoloration of 11, 13, 23 and 41. Both lower first permanent molars were root canal treated at the age of 9 and given metal crowns. The upper permanent molars showed large composite restorations with hypomineralized tooth surfaces. According to the classification of MIH by Mathu – Muju and Wright, this case could be classified as Severe MIH, i.e. post-eruptive enamel breakdown, crown destruction, caries associated with affected enamel, history of dental sensitivity and aesthetic concerns.

styleitaliano style italiano mih related brown spot

Pre operative upper anterior close up reveals a well demarcated brown lesion with 11. The lesions on the other teeth were not a primary concern for the patient hence it was decided to only treat the lesion on 11 and also 23 which showed a discontinuity of the mesial surface, making it prone to caries. The lesions on 13 and 41 had a hard enamel surface and would be checked at regular follow op visits for further treatment. Tooth 11 would be treated with macroabrasion, Deep Resin Infiltration (with ICON) and composite restoration, while tooth 23 would be treated with a proximal composite restoration.

styleitaliano style italiano isolation of tooth with brown spot

Isolation with rubber dam is mandatory to ensure excellent protection of the soft tissues and too create contaminant-free environment for infiltration of the lesion and for bonding of the composite.

styleitaliano style italiano macroabration of incisor before resin infiltration

Macroabrasion is done with a large round bur at slow speed to remove the superficial enamel. This allows deeper penetration of the acid and subsequently the infiltrant to effectively mask the discoloration. The enamel is removed with a very smooth, shallow and controlled movement of the bur without causing any deep pits.

styleitaliano style italiano coarse disc working the surface of an incisor

A coarse disc (Shofu Snap on Disc) is used to smoothen the margins of the preparation to allow better blending of the composite material.

styleitaliano style italiano etching tooth with hydrochloric acid

Icon Etch is applied on the affected area for 2 mins. The hydrochloric acid helps permeabilize the non porous enamel surface.

styleitaliano style italiano treatment of brown spot

After thoroughly washing the etching gel and drying the surface, the next step in the infiltration technique is the Icon Dry (alcohol solution). It is applied for 2 minutes in order to visualize the result achievable with resin infiltration. If the desired result is not achieved, these 2 steps can be repeated up to maximum 3 times, according to manufacturer’s instructions.

styleitaliano style italiano aspect after double etching of brown spot

We decided to stop after 2 cycles of Etch and Dry.

styleitaliano style italiano infiltration of hypo-mineralized area with resin

After using a mylar strip to separate the teeth, the Icon Infiltrant is applied on the tooth surface for 3 minutess and then photocured for 40 seconds. This is repeated for 1 minute more and photocured.

styleitaliano style italiano tooth after resin infiltration before composite restoration

This was the situation after resin infiltration. Some yellow area is still visible but it will be covered with a layer of composite resin.

styleitaliano style italiano incisor after infiltration and composite restoration

After adding a Body shade composite (Filtek Z350Xt, 3M), the restoration was finished and polished.

style italiano styleitaliano 3m
style italiano styleitaliano 3m
styleitaliano style italiano light curing of composite

Photocuring under a layer of glycerin gel.

styleitaliano style italiano immediately after brown spot correction

Immediate post operative result. We must always wait for rehydration of the teeth for at least 48 hours to assess the final result.

styleitaliano style italiano two weeks after brown spot treatment

Final situation after 2 weeks showing acceptable integration and aesthetics.

styleitaliano style italiano smile after treatment of brown spot

Final smile.


When used following the correct techniques and protocols, ICON can be used to treat discolorations in the aesthetic zone of patients with MIH to provide them with a minimally invasive solution and acceptable aesthetics, restoring their lost confidence.


1. Padavala S, Sukumaran G. Molar Incisor Hypomineralization and Its Prevalence. Contemp Clin Dent. 2018;9(Suppl 2):S246-S250. doi:10.4103/ccd.ccd_161_18
2. Almuallem, Z., Busuttil-Naudi, A. Molar incisor hypomineralisation (MIH) – an overview. Br Dent J 225, 601–609 (2018).
3. Attal J P, Atlan A, Denis M, Vennat E, Tirlet G . White spots on enamel: treatment protocol by superficial or deep infiltration (part 2). Int Orthod 2014; 12: 1–31.
4. Paris S, Schwendicke F, Keltsch J, Dorfer C, Meyer-Lueckel H . Masking of white spot lesions by resin infiltration in vitro. J Dent 2013; 41: 28–34.
5. Shaalan O. Bleaching, microabrasion and composite restoration. 2019
6. Manauta J, Salat A. Layers, An atlas of composite resin stratification. Chapter 5. Quintessence Books, 2012.


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