Colorimetric, Ultra-structural and Elemental Comparison of Dental Enamel Defects

Colorimetric Comparison of Email Defects Using Spectrophotometric and Computer Techniques and Biological, Structural and Physico-chemical Analyses of Teeth or Pathological Enamel

The study focuses on the analysis of enamel defects grouping together hypomineralization and hypoplasia. It focuses on 3 very characteristic enamel pathologies that are most often encountered in dental consultations: Molar Incisor Hypomineralization (MIH), dental fluorosis (FD) and amelogenesis imperfecta (AI). The research focuses on the use of a spectrophotometer for measuring tooth colors: the Zfx SpectroShade® (MHT) and its software as a means of early diagnosis of pre-eruptive enamel abnormalities. The main objective of the study is to analyze the color parameters of teeth affected with one of the 3 enamel abnormalities for use of the spectrophotometer as a non-invasive diagnostic tool for enamel defects.

The secondary objective is focused on the biological, structural and physicochemical characterizations of these different enamel pathologies from extracted teeth or enamel biopsies that must be ground to achieve a restoration.

Methodology:

V1 inclusion visit (D1):

The subjects will be screened during a consultation carried out as part of the treatment in the participating dentistry departments. The inclusion and non-inclusion criteria for participants will be verified and the study will be offered to eligible patients and controls. The research briefing note will be given and the non-objection of the participants (adults and representative (s) of parental authority) will be collected. The investigator will then take the photographs and spectrophotometer shots (at least 2 teeth per participant).

V2 follow-up visit (within 2 months of the inclusion visit (D2 to M2)):

The patients will be reviewed in consultation as part of the treatment for selective grinding for dental restoration or extraction (if the tooth (s) is (are) no longer storable). The teeth or pathological enamel samples will be recovered and centralized at the Laboratory of Oral Molecular Physiopathology.

Biological, structural and physico-chemical analyzes will be carried out from these samples.

In order to ensure follow-up of participants, the principal investigator of each center will maintain a correspondence table including the participant's identity and his research identification number. He will also keep a register of oppositions up to date.

The subject's opposition or participation will be notified in his medical file. A copy of the briefing notes and non-objection forms signed by the dentist will be kept on site with the research documents. Minors who become adults during their participation will benefit from appropriate information and their non-objection will be collected.

Primary endpoint Analysis, using the spectrophotometer, of the numerical values of the color of the teeth in each of the populations studied (Hereditary amelogenesis imperfecta (AIH), dental fluorosis (FD), Hypomineralization Incisors and Molar (MIH) and control).

For each pathology, the values of these parameters will be compared. Secondary endpoints

• Intra-pathology classification according to the severity of each pathology.
• Characterization and biological, structural and physicochemical analysis of these different pathologies from extracted teeth or enamel biopsy to be ground to achieve a restoration.

Sample analysis The teeth samples will be stored at room temperature in the Oral Molecular Physiopathology laboratory in the Research Center.

During the research, biological, structural and physicochemical analyzes will be carried out at the laboratory or in another laboratory in France or abroad. A contract will be established upstream of these analyzes with the partner laboratory.

At the end of the research, samples not destroyed by destructive analysis techniques will be embedded in the resin and stored for 10 years before being destroyed. These samples can be used for additional analyzes (biological, structural and physico-chemical) according to the request of the references for the publication process.

For patients :

Inclusion Criteria :

1. Age between 8 and 55 years old
2. Carrier of one of the following 3 quantitative pre-eruptive enamel anomalies : AIH, dental fluorosis or MIH
3. Information and collection of the non-opposition of the adult patient or of the representative(s) of parental authority present for the minors.

Criteria for non-inclusion :

1. Pregnant or breastfeeding woman
2. Under guardianship or curators
3. Opposition of the minor patient
4. Presenting pre-eruptive anomalies only on the molars (the spectrophotometer can only take pictures of the anterior dental sector (incisors and canines)).
5. Other types of hypomineralization (post-eruptive, of traumatic or infectious origin, idiopathic).
6. Having undergone radiotherapy or chemotherapy inducing dental and periodontal damage.
7. Having systemic abnormalities (unbalanced diseases), haemochromatosis, porphyria
8. Under medication likely to disturb the coloring of the teeth

For witnesses :

Inclusion Criteria :

1. Age between 8 and 55 years old
2. Information and collection of the non-opposition of the adult witness or of the representative(s) of parental authority present for the minors.
3. Free of any anomaly of tooth structure, exogenous dyschromia and carious lesions.

Criteria for non-inclusion :

1. Pregnant or breastfeeding woman
2. Under guardianship or curators
3. Opposition of the minor witness
4. Carrier of a quantitative pre-eruptive enamel anomaly
5. Polycarpus (preventing the diagnosis of amyl hypomineralization)