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OpenTrials
Completed

NCT Number: NCT07837960

Exploration of Diagnosis, Etiology, and Prognosis Prediction of Cracked Teeth in Young Adults

Cracked teeth are a common dental problem where tiny cracks form in the teeth. These cracks can be hard to find early, and if not treated, they may cause the tooth to break. This study aims to see if a new, non-invasive imaging method called Near-Infrared Imaging (NIRI) can help us find these cracks better in young adults aged 18 to 30 years. Participants will attend a single dental visit where they will receive a standard dental examination, including checks for pain when biting or when the tooth is tapped or exposed to cold. Additionally, pictures of their teeth will be taken using a special NIRI camera that uses a safe, painless light, and their teeth will be examined closely using a dental operating microscope, which is the current standard method for comparison. The main goals are to evaluate how accurate the NIRI method is compared to the microscope, to determine if NIRI can serve as a reliable alternative or helpful supplement for dentists, and to identify patterns and factors such as tooth position, wear, and bite that may be linked to cracked teeth, helping dentists recognize patients at higher risk. The study enrolled participants from September 2025 to March 2026 at the School and Hospital of Stomatology, Fujian Medical University.

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Key information

Conditions

Cracked Tooth Syndrome Bites and Stings Chemically-Induced Disorders Poisoning Stomatognathic Diseases Tooth Diseases Tooth Fractures Tooth Injuries Tooth Wear Wounds and Injuries

Age range

18 year–30 year

Sex eligibility

All sexes

Study type

Observational

Primary location

Fujian Medical University Stomatological Hospital

Fuzhou, Fujian, 350002, China

About this study

The diagnosis of cracked teeth relies heavily on subjective clinical findings, including patient-reported pain upon biting, cold sensitivity, and visual inspection under magnification. However, these methods lack objective quantifiable measures, often leading to delayed or missed diagnoses. Near-Infrared Imaging (NIRI) has emerged as a promising non-invasive imaging modality that can detect subtle structural changes in tooth hard tissues. This study is designed to systematically evaluate the diagnostic utility of NIRI in detecting cracked teeth among young adults, using the dental operating microscope (OM) combined with clinical examination as the reference standard. This study was designed as a prospective, self-controlled, diagnostic accuracy trial. All participants underwent both diagnostic examinations: the index test was near-infrared imaging (NIRI) and the reference standard was operating microscope (OM) combined with conventional clinical examination.

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

Adults aged 18 to 30 years old Presence of ≥20 natural teeth that are either unrestored or have minor restorations Willingness to provide written informed consent Capability to cooperate with clinical oral examination and NIRI scanning

Exclusion criteria

Presence of <20 natural teeth History of radiotherapy or surgery in the maxillofacial region Inability to cooperate with clinical examinations or questionnaire surveys History of facial trauma Undergoing orthodontic treatment

Treatment and study plan

Observational Assessment Only

Other

This is an observational diagnostic study with no therapeutic intervention administered. Participants undergo a single baseline oral examination, including clinical assessment of occlusion, tooth wear, restoration status, and symptoms (biting pain, cold-stimulus pain, percussion pain), followed by two diagnostic imaging procedures: Near-Infrared Imaging (NIRI) and operating microscope (OM) examination. All procedures are non-invasive and performed for diagnostic data collection purposes only. No drug, device, or therapeutic procedure is administered as part of the study protocol.

Primary outcomes

  1. Sensitivity and Specificity of NIRI for Detecting Cracked Teeth

    Time frame: At baseline upon completion of oral examinations

    Sensitivity and specificity of Near-Infrared Imaging (NIRI) for detecting cracked teeth, using dental operating microscope (OM) examination as the reference standard. Calculated at both the tooth level and the patient level with 95% confidence intervals.

  2. Positive and Negative Predictive Values of NIRI for Detecting Cracked Teeth

    Time frame: At baseline upon completion of oral examinations

    Positive predictive value (PPV) and negative predictive value (NPV) of Near-Infrared Imaging (NIRI) for detecting cracked teeth, using dental operating microscope (OM) examination as the reference standard. Calculated at both the tooth level and the patient level with 95% confidence intervals.

  3. Area Under the ROC Curve (AUC) of NIRI for Detecting Cracked Teeth

    Time frame: At baseline upon completion of oral examinations

    Overall discriminative ability of Near-Infrared Imaging (NIRI) assessed by the area under the receiver operating characteristic curve (AUC), with 95% confidence intervals at both the tooth and patient levels.

Secondary outcomes

  1. Diagnostic Agreement Between NIRI and Operating Microscope（OM）

    Time frame: At baseline upon completion of oral examinations

    Cohen's Kappa statistic evaluating the inter-method agreement between Near-Infrared Imaging (NIRI) and operating microscope (OM) examination for cracked tooth diagnosis.

  2. Patient-Level Prevalence of Cracked Teeth

    Time frame: At baseline upon completion of oral examinations

    Proportion of participants classified as crack-positive by operating microscope (OM) examination, reported as a descriptive prevalence estimate in the study population.

  3. Crack Status and NIRI Diagnostic Performance by Tooth Position

    Time frame: At baseline upon completion of oral examinations

    Proportion of teeth classified as crack-positive by operating microscope (OM) examination, reported separately for anterior teeth, premolars, and molars as percentages of examined teeth in each tooth position category. Subgroup analyses of the primary outcomes (sensitivity, specificity, PPV, NPV, and AUC with 95% CIs) are reported separately for each tooth position, using OM as the reference standard.

  4. Crack Status and NIRI Diagnostic Performance by Tooth Wear

    Time frame: At baseline upon completion of oral examinations

    Proportion of teeth classified as crack-positive by OM examination, reported for teeth with versus without wear based on the Smith and Knight Tooth Wear Index (grades 0-4). Subgroup analyses of the primary outcomes (sensitivity, specificity, PPV, NPV, and AUC with 95% CIs) are reported by wear grade, using OM as the reference standard.

  5. Crack Status and NIRI Diagnostic Performance by Clinical Symptoms

    Time frame: At baseline upon completion of oral examinations

    Proportion of teeth classified as crack-positive by OM examination, reported separately for each clinical symptom (tenderness to percussion, pain on biting, and positive cold test). Subgroup analyses of the primary outcomes (sensitivity, specificity, PPV, NPV, and AUC with 95% CIs) are reported separately for teeth with versus without each symptom, using OM as the reference standard.

  6. Crack Status and NIRI Diagnostic Performance by Caries and Restoration Status

    Time frame: At baseline upon completion of oral examinations

    Proportion of teeth classified as crack-positive by OM examination, reported separately by caries status, filling status, and prosthetic restoration status. Subgroup analyses of the primary outcomes (sensitivity, specificity, PPV, NPV, and AUC with 95% CIs) are reported separately for each condition, using OM as the reference standard.

  7. Crack Status and NIRI Diagnostic Performance by Special Dental Conditions

    Time frame: At baseline upon completion of oral examinations

    Proportion of teeth classified as crack-positive by OM examination, reported separately for each special dental condition (enamel hypoplasia, lateral displacement, joint clicking, central cusp deformity, and fused tooth). Subgroup analyses of the primary outcomes (sensitivity, specificity, PPV, NPV, and AUC with 95% CIs) are reported separately for each condition, using OM as the reference standard.

  8. Patient-Level Crack Status and NIRI Diagnostic Performance by Occlusal Factors

    Time frame: At baseline upon completion of oral examinations

    Proportion of participants classified as crack-positive by OM examination, reported separately by occlusal factors (sex, overbite, overjet, and molar relationship). Subgroup analyses of the primary outcomes (sensitivity, specificity, PPV, NPV, and AUC with 95% CIs) are reported at the patient level, stratified by each occlusal factor, using OM as the reference standard.

Other outcomes

  1. Positive and Negative Percent Agreement Between NIRI and OM

    Time frame: At baseline upon completion of oral examinations

    Positive percent agreement and negative percent agreement between Near-Infrared Imaging (NIRI) and operating microscope (OM) for cracked tooth detection, with 95% confidence intervals.

  2. Patient-Level Prevalence of Cracked Teeth

    Time frame: At baseline upon completion of oral examinations

    Proportion of participants classified as crack-positive by operating microscope (OM) examination, reported as a descriptive prevalence estimate in the study population.

  3. Prevalence of Clinical Symptoms in Crack-Positive Teeth

    Time frame: At baseline upon completion of oral examinations

    Descriptive prevalence of clinical symptoms (biting pain, cold-stimulus pain, and percussion pain) among crack-positive teeth identified by operating microscope examination.

Sponsors and collaborators

Lead sponsor

Fujian Medical University

Other

Registry information

Acronym: CDCP

Important dates

Study start
2025
Primary completion
2026
Study completion
2026
First posted
Sep 24, 2026
Registry last updated
Sep 24, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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