# Hypersensitivity in Molar Incisor Hypomineralization: Superficial Infiltration Treatment
## 2 Materials and Methods  
This study was approved by the Ethics Committee of the Area Vasta Emilia Nord, Emilia Romagna, Italy (EC Prot. # 307/2018/OSS/AOUMO). All patients' parents/legal guardians read and signed an informed consent for participation in the study and authorization for treatment. Sixty-seven pediatric patients (6 to 14 years old) were selected from the Department of Pediatric Dentistry, University of Modena and Reggio Emilia. The recruitment period lasted 3 months. Patients were assessed by a dental expert in restorative treatments (A.M.D.D.) and subjects who presented visual enamel defects of permanent molars due to MIH, according to the diagnostic criteria proposed by the European Academy of Pediatric Dentistry (EAPD) in 2010 [18], were considered for study inclusion. Patients with sensitivity of at least one of the molars affected by MIH, or with post eruptive enamel fractures, but without dentin involvement or cavitated carious lesions were approached (Figure 1). Bitewing examinations were performed to exclude interproximal carious lesions. Twenty-five patients were excluded due to lesions with dentin involvement or cavitated and interproximal caries. The patient was asked to respond to a questionnaire regarding the selected tooth's sensitivity, both prior to and following the treatment. The patients' parents or legal  
Figure 1: Clinical view of enamel defects of permanent molars due to molar incisor hypomineralization (MIH). guardians were asked to respond to questions regarding time of gestation, maternal health during gestation, child's weight at delivery, complications during childbirth, diseases in early childhood, breastfeeding, antibiotics assumption during the first two years of life, administration of fluoride-based tablets, and family history of MIH. All information was recorded by an operator and stored in a dedicated database. Before treatment, the following parameters were recorded into a dedicated Excel spreadsheet: plaque accumulation evaluated by the full mouth plaque score (FMPS) [19], periodontal status with the Loe and Silness gingival index (GI) [20], and bleeding on probing (BoP) with the caton bleeding score [21]. Sensitivity was determined by the examiner using the Schiff cold air sensitivity scale (SCASS), measured by responses to a thermal, cold air jet stimulus (0 = subject does not respond to stimulus, 3 = subject responds to stimulus, considers stimulus to be painful, and requests discontinuation of the stimulus) [22]. Sensitivity to tactile stimulation (during oral hygiene and eating ice cream) with patients' response to the intensity of pain was registered according to the Wong-Baker faces scale (WBFS) for pediatric patients (0 = no pain, 10 = intense pain) [23]. All measurements of clinical parameters were repeated at baseline (T0), immediately after treatment (T1), one week (T2), one month (T3), and twelve months (T4) after treatment. The superficial infiltration technique was performed with ICON (DMG, Hamburg, Germany) [14; 24; 25], an infiltration system that appears to be extremally useful in the treatment of initial caries and enamel alterations. Manufacturer instructions were followed, with the exception of the etching phase, and carried out with orthophosphoric acid rather than with hydrochloric acid, given the greater porosity of the tissue and the high hypersensitivity of the patient. This technique allows, after an initial erosion phase of the most superficial enamel layer, to infiltrate the porosity system of the defect with a low viscosity resin. The procedure included no anesthesia, rubber dam isolation followed by affected tooth cleaning and removal of any cleaning residue with water spray, 30 s of etching with 37% orthophosphoric acid, 30 s of drying with Icon Dry, 3 min of infiltration with Icon Infiltration, and 40 s of light curing. The application of Icon Infiltration should be repeated for 1 min, followed by 40 s of light curing and final polishing.