Evaluation of the Occlusal Effects of Stainless Steel Crowns Placed Using the Modified Hall Technique in Permanent Molars Affected by Molar-Incisor Hypomineralization
Trial Snapshot
- Phase
- Not Applicable
- Status
- Not yet recruiting
- Sponsor
- Enrollment
- 46
- Locations
- 1
- Primary Endpoint
- Cusp Tip Displacement (Linear Measurement in mm)
Study Overview
Brief Summary
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.
Detailed Description
The aim of this study is:
- to evaluate the occlusal adaptation process following SSC placement using the modified Hall technique in first permanent molars affected by MIH.
- to quantify three-dimensional occlusal changes, including cusp displacement, occluso-vertical dimension changes, and occlusal contact area alterations over time using digital model superimposition.
- to investigate the potential effects of this treatment on surrounding structures by assessing temporomandibular joint function and periodontal parameters.
MIH is a developmental enamel defect primarily affecting permanent first molars and often leading to hypersensitivity, rapid post-eruptive enamel breakdown, and significant coronal destruction. Recent literature has increasingly recommended biologically oriented and minimally invasive approaches for restoring MIH-affected molars, including the Hall technique and its modifications, which allow SSC placement without conventional tooth preparation. Although SSC placement is clinically successful, it may temporarily increase the occluso-vertical dimension and alter occlusal contacts. While clinical observations suggest that occlusal relationships gradually adapt over time through dentoalveolar compensation, no studies to date have quantitatively evaluated three-dimensional occlusal adaptation following SSC placement in MIH-affected permanent molars.
This prospective longitudinal clinical study will include 46 children with MIH-affected first permanent molars requiring SSC restoration. SSCs will be placed using the modified Hall technique.
Teeth will be equally distributed between maxillary and mandibular arches (23 maxillary and 23 mandibular molars), with only one tooth included per participant. Eligibility for SSC placement will be determined using the MIH-TNI index; teeth with scores 2 and 4 will be considered for inclusion. In cases where more than one first permanent molar meets the inclusion criteria within the same patient, the tooth showing the greatest degree of coronal breakdown will be selected for SSC placement. If multiple teeth present with similar severity level, tooth selection will be determined by computer-generated randomization. To minimize potential occlusal interference during treatment, all other necessary restorative procedures will be completed before SSC placement. Any additional teeth requiring SSC restoration will receive caries management during initial visits, while crown placement for those teeth will be postponed for three months to avoid interference with occlusal assessment.
Study Design
- Study Type
- Interventional
- Allocation
- Non Randomized
- Intervention Model
- Parallel
- Primary Purpose
- Treatment
- Masking
- Single (Outcomes Assessor)
Masking Description
The biostatistician performing the data analysis will be blinded to group allocation. The clinician performing treatment and model analysis will not be blinded.
Eligibility Criteria
- Ages
- 6 Years to 14 Years (Child)
- Sex
- All
- Accepts Healthy Volunteers
- Yes
Inclusion Criteria
- •for Participants
- •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
- •Emergency dental needs (e.g., toothache or acute conditions) previously managed
- •Presence of at least one permanent first molar with an MIH-TNI score of 2 or 4 requiring SSC restoration
- •No pain, clicking, or functional limitation in the temporomandibular joint region
- •Children and their legal guardians who read, understand, and provide written and verbal informed consent Inclusion Criteria for Tooth
- •Permanent first molars with MIH Treatment Need Index (MIH-TNI) score of 2 or 4 indicating the need for SSC restoration
- •Occlusal contact with the opposing tooth maintained at maximum intercuspation despite post-eruptive enamel breakdown, with a noticeable reduction in posterior occluso-vertical dimension
- •Absence of clinical and radiographic signs or symptoms associated with irreversible pulp inflammation or necrosis
- •Absence of gingival or periodontal pathology in the surrounding soft tissues
Exclusion Criteria
- •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
Arms & Interventions
Maxillary First Permanent Molar
A preformed SSC will be placed and cemented on the selected MIH-affected first permanent molar using the modified Hall technique. The procedure will involve selective caries removal while avoiding conventional tooth preparation, and local anesthesia will be administered only when clinically indicated.
Digital intraoral scans and bite registrations will be obtained at 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) for occlusal analysis.
Intervention: Modified Hall Technique (Procedure)
Mandibular First Permanent Molar
A preformed SSC will be placed and cemented on the selected MIH-affected mandibular 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 intraoral scans and bite registrations will be obtained at 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) for occlusal analysis.
Intervention: Modified Hall Technique (Procedure)
Outcomes
Primary Outcomes
Cusp Tip Displacement (Linear Measurement in mm)
Time Frame: From crown placement to 3 months post-placement
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)
Time Frame: From crown placement to 3 months post-placement
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)
Time Frame: From crown placement to 3 months post-placement
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.
Secondary Outcomes
- Change in Maximum Occlusal Contact Area (Surface Area Measurement in mm²)(From crown placement to 3 months post-placement)
- Assessment of Probing Depth (Linear Measurement in mm)(From crown placement to 3 months post-placement)
- Assessment of Temporomandibular Joint Function (Helkimo Dysfunction Index Score)(From crown placement to 3 months post-placement)
- Assessment of Gingival Status (Gingival Index Score)(From crown placement to 3 months post-placement)
- Assessment of Plaque Accumulation (Plaque Index Score)(From crown placement to 3 months post-placement)