Correlation Between Colour of Defect and Enamel Breakdown in First Permanent Molars With Molar Incisor Hypomineralisation (MIH)

Official title

Molar-Incisor Hypomineralisation (MIH): Correlation Between Colour of Defect and Enamel Breakdown

Overview

Cheese molars (MIH) can be recognized not only by their colour abnormalities but also by the enamel breakdown. Clinical management of those teeth may become challenging by the chronic hypersensitivity, that makes various steps during treatment, such as pain control or light curing of any type of composite restorations, difficult or even impossible, despite profound local anaesthesia. The aim of this study is to determine the relationship between colour of the defect and loss of ename in the affected teeth. A correlation between colour of the defect and risk of enamel breakdown could enable early prognosis leading to preventive measures in order to delay or even avoid completely any breakdown of the enamel. Children diagnosed with MIH on their first permanent molars of different severity are matched to children with sound molars. They are identified by the annual school dental check-up and are invited to take part in the study. The children will be invited to the university dental clinic via letter for the first appointment. Upon parental consent, the teeth will be photographed and scanned on the first appointment. Three follo-up appointments will be organised in order to take pictures and scan again the teeth. The baselne scan of the tetth will be compared to the scans of the subsequent appointments in order to measure the level of enamel breakdown and correlate it to the colour of the defect.

Detailed description

Aim of the study is the correlation between the colour of the enamel defect and enamel breakdown in young first permanent molars. Children diagnosed with MIH from the onset of eruption of the first permanent molar, matched by age with children with sound first permanent molars are investigated. Children screened by the school dental services of Basel-Stadt as well children attending the department of children and adolescents (KJZM) of the University Centre for Dental Medicine in Basel (UZB), diagnosed with MIH on one or more first permanent molars receive a letter of information- invitation to be seen in the department of children and adolescents (KJZM). The control group consists of fit and healthy children 5-8 years old, who attend the department of children and adolescents (KJZM-UZB) for their regular dental check-ups. A written informed consent will be obtained from the parents/legal guardians.

Colour definition:

The exact colour determination of the teeth will be carried out as follows: the teeth are photographed with a canon SLR camera. (Canon EOS 80D; Canon inc. Japan), a ringflash (Macro Ring Lite MR-14EXII; Canon) and a macro lens (EF-S 60mm 1:2:8 USM; Canon) will be used. All camera settings (1/250, aperture F20, iso-sensitivity 100 and a fixed white balance AWBW (white priority), flash intensity +/-0) and the tooth-lens distances (25 cm) are standardized by one operator (VM, SR). A colour reference card (grey card) is photographed together with the tooth of interest in order to identify and equalize the colour deviations. The resulting photo will be uploaded to the Adobe Photoshop 6 and the values of the RGB code (0-255 for each of the three colours) will be determined. The tolerance range is set to +/- 10. If the 3 colours are within the tolerance, the photo can be used to determine the colour of the tooth to be examined. The darkest part of the tooth is then determined. The degree of darkness is indicated by a number between zero and one hundred, where L=100 is white and L=0 is black (Wiedrichs et al. 2023).

Degree of enamel loss will be investigated and measured as follows:

The teeth will be scanned using the iTero 5D Plus intraoral scanner in the first appointment and then at 3, 6 and 9 months. The obtained stl file is optimised for the subsequent digital superimposition procedures. The distances between surface points of the two digital models (initial scan vs scan at 3months, initial scan vs scan at 6 months and initial scan vs scan at 9 months) will be converted to root mean square (RMS) values that assess the mean value of errors in the comparison of two datasets with an identical coordinate system. The RMS values represent the data of trueness or loss of enamel. The results of deviation analysis will be complemented by visualisation of the 3D colour-coded maps in which the yellow-to-red fields indicate that distance values are greater than the positive limits while turquoise-to-dark blue fields indicate that distance values are smaller than the negative limits. The range of tolerance (green color) is set at ± 0.05 mm, which means that the software report surface differences in the color-coded maps only beyond this range.

Primary outcome measures

• Colour of the defect [Time frame: Baseline appointment until the 9-months follow-up appointment]
• Enamel breakdown [Time frame: From enrollment to the last follow-up appointment at 9 months]

Eligibility criteria

MIH Study Group

Inclusion criteria

• Children between 5 to 8 years with MIH molars with or without hypersensitivity according to the MIH-TN Index (Bekes et al 2016)
• Children with first molars in occlusion
• Children fit and healthy

Exclusion criteria

• MIH first permanent molars that have already received any kind of dental treatment
• Children diagnosed with HSPM (hypomineralised second primary molars)
• Children older than 8 years - Children younger than 5 years
• Children with any cranio-facial and/or other developmental dental defects
• Children diagnosed with parafunctions (attrition/ erosion)
• Children and/or parents who did not consent to the study
• Children with MIH teeth that show clinically visible enamel loss during the eruption
• Children without the first molars in occlusion

Non- MIH Control Group

Inclusion criteria

• Children between 5 to 8 years with no clinically affected molars- Page 4 of 5
• Children fit and healthy

Exclusion criteria

• Children who have already received any kind of dental treatment on their permanent or primary teeth
• Children diagnosed with MIH or any other disease of the teeth
• Children older than 8 years
• Children younger than 5 years
• Children with any cranio-facial and/or other developmental dental defects
• Children diagnosed with parafunctions (attrition/ erosion)
• Children and/or parents who did not consent to the study

Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.

Healthy volunteers: Yes

Study design

Observational model

Case-control

Study locations

Switzerland · 1 center

• University Centre for Dental Medicine — Basel

Identifiers

NCT: NCT07727200 · MIH UZB 2024-02231

Primary sources (government registries)

• ClinicalTrials.gov (US NIH)

View this study on ClinicalTrials.gov ↗