Molar-incisor hypomineralization (MIH) frequently affects permanent first molars and increases the risk of rapid post-eruptive breakdown and restorative failure. Stainless steel crowns (SSCs) are considered a reliable treatment option for severely affected molars; however, SSC placement may temporarily alter the occlusal vertical dimension and occlusal contacts. Quantitative evidence describing the occlusal adaptation process following SSC placement in MIH-affected permanent molars is limited.
This prospective longitudinal clinical study aims to evaluate occlusal adaptation after SSC placement using the modified Hall technique in MIH-affected permanent first molars. Forty-six children will be included. Intraoral scans will be obtained at baseline, immediately after treatment, and during follow-up visits up to 3 months. Digital models will be superimposed to measure three-dimensional changes in cusp position, occluso-vertical dimension, and occlusal contact area. Temporomandibular joint function and periodontal parameters will also be assessed. The results are expected to provide quantitative evidence on occlusal adaptation following SSC treatment in MIH-affected molars.
Absence of any skeletal anomalies
ASA physical status I or II according to the American Society of Anesthesiologists classification
Frankl behavior rating score of 3 or 4
All permanent first molars erupted and in contact at maximum intercuspation
Individuals with serious systemic or psychological conditions
Participants who fail to attend follow-up appointments
Those who exhibit excessive fear or anxiety reactions and are unable to cooperate during treatment
Parallel
Modified Hall Technique
Procedure/SurgeryA preformed SSC will be placed on the selected MIH-affected first permanent molar using the modified Hall technique. The procedure will involve selective caries removal while maintaining a minimally invasive approach and avoiding conventional tooth preparation. Local anesthesia will be administered only when clinically indicated. Digital Scan and Bite Registration Schedule * T0 (Baseline): Immediately before crown placement * T1 (Immediate): Immediately after crown placement * T2 (Two Weeks): Two weeks after crown placement * T3 (One Month): One month after crown placement * T4 (Three Months): Three months after crown placement. At each time point (T0-T4), digital scans of both the maxillary and mandibular arches will be obtained, and a buccal bite registration will be recorded. In addition, temporomandibular joint examination and periodontal evaluation of the tissues surrounding the crowned tooth will be performed at T0, T2, T3, and T4 follow-up visits.
Cusp Tip Displacement (Linear Measurement in mm)
Positional changes of the mesiobuccal, mesiolingual/palatal, distobuccal, and distolingual/palatal cusp tips of all first permanent molars, including the crowned tooth, will be measured and recorded in millimeters using digital model superimposition across time points. In cases where one or more cusp tips of the crowned tooth are absent due to coronal breakdown, the distances between the corresponding cusp tips of the stainless-steel crown and their projected anatomical locations on the original tooth surface will be measured.
Anterior Vertical Distance (Linear Measurement in mm)
The vertical distance between the cusp tips of the maxillary and mandibular primary/permanent canines located on the same side as the crowned tooth will be measured at each time point: T0 (immediately before crown placement), T1 (immediately after crown placement), T2 (two weeks after crown placement), T3 (one month after crown placement), and T4 (three months after crown placement). Measurements will be compared across time points to evaluate potential anterior vertical positional changes associated with SSC placement. If the canine on the treated side is not clinically visible in the oral cavity, the measurement will be performed between the opposing canines in the contralateral arch.
Posterior Vertical Distance (Linear Measurement in mm)
The vertical distance between the mesiobuccal cusp tips of the maxillary and mandibular first permanent molars on both the right and left sides will be measured and recorded in millimeters. Measurements will be obtained at each time point (T0: immediately before crown placement, T1: immediately after crown placement, T2: two weeks after crown placement, T3: one month after crown placement, and T4: three months after crown placement) and compared across time points to evaluate posterior vertical positional changes.
Change in Maximum Occlusal Contact Area (Surface Area Measurement in mm²)
The change in maximum occlusal contact areas (in mm²) will be analyzed based on bite registration records. Since the 3Shape software does not allow direct quantitative measurement of occlusal contact areas, the analysis will be performed using the color-coded occlusal contact maps generated by the software. Specifically, the red zones representing the areas of maximum contact will be identified from the screenshots, and their surface areas will be measured using the ImageJ software. This analysis will be two-dimensional, based on calibrated screenshots, and will provide a comparative assessment of occlusal contact area changes across different time points: T0: immediately before crown placement, T1: immediately after crown placement, T2: two weeks after crown placement, T3: one month after crown placement, and T4: three months after crown placement.
Assessment of Temporomandibular Joint Function (Helkimo Dysfunction Index Score)
Temporomandibular joint (TMJ) function will be assessed at predefined follow-up time points: T0 (baseline, immediately before crown placement), T2 (two weeks after crown placement), T3 (one month after crown placement), and T4 (three months after crown placement) using a pediatric-adapted modification of the Helkimo Clinical Dysfunction Index. The index includes five parameters: maximum mouth opening, deviation during opening, joint function impairment, TMJ pain on palpation, and masticatory muscle pain. Each parameter is scored as 0 (none), 1 (mild), or 2 (severe), and the total composite dysfunction score (range: 0-10; higher scores indicate worse dysfunction) is obtained by summing all parameters. Scores will be categorized as 0 = no dysfunction, 1-4 = mild (Grade I), 5-9 = moderate (Grade II), and ≥10 = severe dysfunction (Grade III), and recorded and compared across time points to evaluate changes in TMJ function associated with SSC placement.
Assessment of Gingival Status (Gingival Index Score)
The gingival status of the tissues surrounding the SSC-treated teeth will be evaluated at each time point: T0 (immediately before crown placement), T2 (two weeks after crown placement), T3 (one month after crown placement), and T4 (three months after crown placement). The clinical condition of the gingival tissues will be assessed using the Löe and Silness Gingival Index. Gingival conditions will be assessed at the marginal gingiva and proximal surfaces using a periodontal probe. Scores are defined as follows: 0 = normal healthy gingiva; 1 = mild inflammation (slight color change and edema, no bleeding on probing); 2 = moderate inflammation (redness, edema, glazing, bleeding on probing); 3 = severe inflammation (marked redness and edema, ulceration, possible spontaneous bleeding). Index scores will be recorded and compared across time points to evaluate changes in gingival health associated with SSC placement.
Assessment of Plaque Accumulation (Plaque Index Score)
Plaque accumulation around the SSC-treated teeth will be evaluated at each time point: T0 (immediately before crown placement), T2 (two weeks after crown placement), T3 (one month after crown placement), and T4 (three months after crown placement).Plaque accumulation will be assessed using the Silness and Löe Plaque Index. Assessments will be performed at the marginal gingiva and proximal surfaces using a periodontal probe. Scores are defined as follows: 0 = no plaque; 1 = plaque detectable only by probe or disclosing, not visible clinically; 2 = visible plaque limited to the gingival margin; 3 = abundant plaque accumulation along the gingival margin, including interproximal areas. Index scores will be recorded and compared across time points to evaluate changes in plaque accumulation associated with SSC placement.
Click on the lead sponsor to view all of their trials.
This trial is not recruiting at the moment. You can still explore other options:
