Deep learning-based prediction of indication for cracked tooth extraction using panoramic radiography.

BACKGROUND: We aimed to determine the feasibility of utilizing deep learning-based predictions of the indications for cracked tooth extraction using panoramic radiography. METHODS: Panoramic radiographs of 418 teeth (group 1: 209 normal teeth; group 2: 209 cracked teeth) were evaluated for the training and testing of a deep learning model. We evaluated the performance of the cracked diagnosis model for individual teeth using InceptionV3, ResNet50, and EfficientNetB0. The cracked tooth diagnosis model underwent fivefold cross-validation with 418 data instances divided into training, validation, and test sets at a ratio of 3:1:1. RESULTS: To evaluate the feasibility, the sensitivity, specificity, accuracy, and F1 score of the deep learning models were calculated, with values of 90.43-94.26%, 52.63-60.77%, 72.01-75.84%, and 76.36-79.00%, respectively. CONCLUSION: We found that the indications for cracked tooth extraction can be predicted to a certain extent through a deep learning model using panoramic radiography.

Occlusal veneer restoration treatment outcomes of cracked tooth syndrome: A 22.4-month follow-up study.

OBJECTIVES: The aims of this clinical study were to investigate success rate, vital pulp survival rate, tooth survival rate and patient-reported masticatory ability by evaluating the pain symptoms and signs of the cracked teeth as well as Index of Eating Difficulty (IED) and Oral Health Impact Profile-14 (OHIP-14) questionnaire after cracked teeth were restored with occlusal veneers. MATERIALS AND METHODS: 27 cracked teeth of 24 patients with cold and/or biting pains without spontaneous/nocturnal pains were recruited in this study. The cracked teeth were restored with occlusal veneers fabricated by lithium disilicate ceramic. Cold test and biting test were used to evaluate pain signs. IED and OHIP-14 questionnaire were used to evaluate masticatory ability. FDI criteria was used to evaluate restorations. The paired Wilcoxon test was used to analyze significant differences of detection rate of pain signs, OHIP scores and IED grade before and after restorations. Kaplan-Meier survival curve was used to describe the success rate, vital pulp survival rate, and tooth survival rate. RESULTS: 27 cracked teeth were restored with occlusal veneers with average of 22.4-month follow-up. Two cracked teeth had pulpitis and pain signs of the other cracked teeth completely disappeared. OHIP total scores were significantly reduced after treatment. Scores of 'pain', 'occlusal discomfort', 'uncomfortable to eat', 'diet unsatisfactory' and 'interrupted meals' reduced significantly after treatment. After treatment, IED grades of 25 vital teeth were significantly lower than those before treatment. FDI scores of 25 restorations except for 2 teeth with pulpitis were no greater than 2. The 12 months accumulated pulp survival rate of the cracked teeth was 92.6%. The 12 months accumulated tooth survival rate was 100%. The success rate at the latest recall was 92.6%. CONCLUSION: Occlusal veneer restorations with success rate of 92.6% and the same pulp survival rate might be an effective restoration for treating the cracked teeth. CLINICAL RELEVANCE: The occlusal veneer restorations might be an option for treating the cracked teeth when cracks only involve enamel and dentin, not dental pulp.

Saving Cracked Teeth: The Current State of Evidence.

Treatment planning for cracked teeth can be quite challenging for clinicians, as various outcomes-related clinical parameters must be considered. Historically, extraction was recommended for cracked teeth with radicular extensions due to their poor prognosis. Recent literature, however, suggests that these teeth may be saved with careful case selection and appropriate treatment. This article closely examines Davis and Shariff's 2019 study, which demonstrated a promising prognosis for treating cracked teeth with radicular extensions following a specific treatment protocol. This literature review discusses current findings regarding cracked teeth and suggested treatment modalities to optimize outcomes.

A retrospective clinical study to compare the ability of cone-beam computed tomographic images and periapical radiographs to reveal cracked teeth, split teeth, and teeth with vertical root fractures.

BACKGROUND: This retrospective clinical study aimed to compare the sensitivity of cone-beam computed tomographic (CBCT) images and periapical (PA) radiographs to reveal cracked teeth, split teeth, and teeth with vertical root fractures (VRFs). METHODS: The authors included 98 patients (98 teeth) diagnosed with a longitudinal tooth fracture (LTF) (cracked tooth, split tooth, VRF) through direct visualization after extraction and with comprehensive clinical and radiographic records. They collected demographic, clinical, and radiographic data. The authors evaluated PA radiographs and CBCT images to identify fractures, fracture lines, and the different patterns of bone loss associated with these teeth. They used the McNemar test to compare PA radiographs and CBCT scans when assessing bone loss. They used the Fisher test to determine statistical relationships between fracture types and demographic, clinical, and radiologic traits. They used an analysis of variance test to compare patient age with fracture types. RESULTS: CBCT images were significantly more effective (P < .05) in detecting bone loss patterns associated with LTFs than with PA radiographs, with 71% of cases detected via CBCT images compared with 42% via radiographs. Mean age was significantly greater (P < .05) in patients with teeth with VRFs than in patients with split teeth. A significant relationship was observed between the type of fracture and the following variables: root canal treatment (split, VRF, P = .002), deep probing depth (≥ 5 mm) (VRF, P = .026), and having more than 8 teeth extracted from the mouth (VRF, P = .032). Overall, there was a significant difference (P < .001) between the visualization of fracture lines (45% on PA radiographs, 65% on CBCT images). CONCLUSIONS: CBCT scans provided more information on LTFs than PA radiographs, particularly in the identification of periradicular bone changes. PRACTICAL IMPLICATIONS: CBCT imaging can assist in making the clinical diagnosis of LTFs through observation of bone loss patterns, providing more information than PA radiographs.

Pulp Survival of Cracked Teeth with Reversible Pulpitis after Orthodontic Banding and Coronal Coverage - A Prospective Cohort Study with One Year Follow Up.

INTRODUCTION: The aim of this prospective study was to investigate the 1-year pulp survival of cracked teeth with reversible pulpitis managed with initial stabilization using orthodontic bands, followed by coronal coverage restorations. METHODS: One-hundred-and-twenty-five patients with a cracked tooth with reversible pulpitis each were recruited. Preoperative patient and tooth data were collected. After definitive pulp diagnoses were determined following an interim period of orthodontic banding, coronal coverage restorations were placed. Cox and logistic regression analyses were used to assess possible prognostic factors and to correlate initial time to pulp stabilization while in orthodontic bands with eventual outcome. Pulp survival was determined using both clinical and radiographic findings. RESULTS: One-hundred-and-six cracked teeth were followed up at 1 year. Pulp survival based on clinical and radiographic findings was found in 81 teeth (76.4%). Out of 25 failures, 11 (44%) required root canal treatment (RCT) in the orthodontic band stage and 10 (40%) required RCT during the process of or after coronal coverage restorations. Four teeth (16%) had incidental findings of periapical radiolucencies at the 1-year review without clinical symptoms. Teeth requiring RCT were found to have required longer periods in orthodontic bands prior to a definitive pulp diagnosis (P < .05). CONCLUSION: A step-by-step approach by using orthodontic banding to monitor pulp status may reduce the incidence of RCT required through definitive coronal coverage restorations for cracked teeth with reversible pulpitis.

Survivability of endodontically treated cracked tooth: A systematic review.

BACKGROUND: Literature evidence describes various treatment protocols that have been employed for the effectiveness in improving survival and addressing associated symptoms of cracked teeth. OBJECTIVE: This systematic review investigates the survivability of endodontically treated cracked teeth and associated assessments, focusing on various treatment protocols. METHODS: The PRISMA guidelines were utilised for guiding the article selection framework of this review. A comprehensive search of relevant literature was conducted in May 2023 across various databases, and studies meeting the inclusion criteria were selected. Data extraction, guided by a standardized form, captured crucial details, including study characteristics, treatment protocols, and treatment outcomes, enhancing the consistency and accuracy of information collection. Data extraction and synthesis was done by two reviewers independently. The Newcastle Ottawa tool was used to measure the methodological quality of the study. Six observational studies were eventually included. RESULTS: Mandibular molars are particularly prone to developing cracks, with research indicating a heightened susceptibility to this dental issue. Studies reveal that endodontically treated cracked teeth boast robust overall survival rates ranging from 75.8% to 100%. The risk of bias assessment, utilizing the Newcastle Ottawa scale, indicated a moderate risk across studies, highlighting the necessity for careful interpretation of findings. CONCLUSION: Endodontically treated cracked teeth show marked success in survival, with the incorporation of crowns post-endodontic treatment significantly enhancing longevity and resilience.

Prognostic factors associated with pulp status in patients with cracked teeth treated with occlusal veneer: A 6- through 24-month prospective clinical study.

BACKGROUND: The authors evaluated the prognostic factors associated with pulp status in patients with cracked teeth (CT) treated with occlusal veneer. METHODS: An analysis of 80 CT (71 patients) with 1 or more crack lines (CLs) and normal pulp vitality or reversible pulpitis was performed. All patients received occlusal veneer and their demographic and clinical data were recorded. Pulp status and clinical features were recorded at 1 week and posttreatment at 1, 2, 3, 6, 12, 18, and 24 months. RESULTS: Maxillary first molars were commonly involved (30 [38%]). The number of CLs on the finish line ranged from 1 through 7 and most had 3 CLs (24 [30%]). The number of CLs through preparation on the finish line ranged from 0 through 4, and 2 CLs (42 [53%]) were the most prevalent. During follow-up, 5 of 80 CT progressed to pulp disease, resulting in a success rate of 93.8%. Results of the Cox model and Kaplan-Meier analysis showed that probing depth greater than 6 mm, widening periodontal ligament of apical area, more than 4 CLs on finish line, and more than 2 CLs through preparation on the finish line were risk factors associated with pulp status (P < .05). CONCLUSIONS: Occlusal veneer can protect CT without preventive root canal therapy. PRACTICAL IMPLICATIONS: The success rate and risk factors of pulp disease in CT restored with occlusal veneer are reported.

The treatment outcomes of cracked teeth: A systematic review and meta-analysis.

OBJECTIVES: The aim of this review was to analyze the clinical treatment outcomes of cracked teeth (CT) retaining vital dental pulp (CT-VDP) or undergoing root canal treatment (CT-RCT). SOURCES: A systematic search was conducted in Medline, Embase, PubMed, and Cochrane Library databases. STUDY SELECTION: Studies evaluating tooth survival rate (TSR), pulp survival rate (PSR), and success rate (SR) with at least a one-year follow-up were included. The risk of bias was evaluated with the Newcastle-Ottawa scale. DATA: Twenty-seven studies underwent qualitative analysis, 26 of which were included in the meta-analysis. SR of monitoring without restorative treatments was 80 % at three years. TSR of CT-VDP was 92.8-97.8 % at 1‒6 years, PSR of CT-VDP was 85.6‒90.4 % at 1‒3 years, and SR of CT-VDP was 80.6‒89.9 % at 1‒3 years; TSR of CT-RCT was 90.5‒91.1 % at 1‒2 years, and SR of CT-RCT was 83.0‒91.2 % at 1‒4 years. Direct restorations without cuspal coverage for CT-VDP increased the risk ratio (RR) of pulpal complications (RR=3.2, 95 % CI: 1.51-6.82, p = 0.002) and tooth extraction (RR=8.1, 95 % CI: 1.05-62.5, p = 0.045) compared with full-crown restorations. The CT-RCT without full-crown restorations had an 11.3-fold higher risk of tooth extraction than the CT-RCT with full-crown restorations (p < 0.001). CONCLUSIONS: Monitoring without restorative treatments might be an option for the CT without any symptoms. Direct restorations without cuspal coverage for the CT-VDP could significantly increase the RR of pulpal complications and tooth extraction compared with full-crown restorations. Full-crown restorations are strongly recommended for the CT-RCT. CLINICAL SIGNIFICANCE: Monitoring without restorative treatments could be a viable option for the CT without any symptoms. Full-crown restorations are strongly recommended for the CT with any symptoms and the CT-RCT.

A narrative review of cracks in teeth: Aetiology, microstructure and diagnostic challenges.

OBJECTIVES: To summarize the available evidence of crack formation in teeth and to discuss the limitations of the current clinical diagnostic modalities for crack detection in teeth. BACKGROUND: Cracks are a common clinical finding in teeth and yet clinicians still struggle to identify the full extent and orientation of cracks for their appropriate timely management. The biomechanics of crack development can be due to multiple factors and can differ from an unrestored tooth to a restored or endodontically treated tooth. DATA & SOURCES: This narrative review has been designed following the guidelines published by Green et al. 2006 [1] Published literature in the English language that addresses the objectives of this review up to July 2022 was sourced from online databases and reference lists. The relevance of the papers was assessed and discussed by two reviewers. A total of 101 publications were included in this narrative review. CONCLUSIONS: The initiation and development of cracks in teeth are likely linked to an interplay between the masticatory forces and fracture resistance of the remaining tooth structure. From the identified literature, the quality and quantity of remaining tooth structure in a restored or endodontically-treated tooth affects the biomechanics of crack development compared to an unrestored tooth. The extent, orientation, and size of the cracks do affect a clinician's ability to detect cracks in teeth. There is still a need to develop reliable diagnostic tools that will accurately identify cracks in teeth beneath restorations to enable effective monitoring of their propagation and provide appropriate interventions. CLINICAL SIGNIFICANCE: The development and propagation of cracks in an unrestored tooth differ greatly from a restored and endodontically treated tooth; mainly linked to the quantity and quality of the remaining tooth structure and the forces acting on them. Identifying the extent of cracks in teeth remains challenging for early clinical intervention.

Biting and thermal sensitivity relief of cracked tooth restored by occlusal veneer: A 12-to 24 months prospective clinical study.

OBJECTIVES: To analyze the relief time and risk factors of biting/thermal sensitivity in cracked tooth (CT) restored using occlusal veneer. METHODS: 63 CT were analyzed, and their demographic and clinical data and medical history were collected. Patients were followed-up to examine the relief of thermal/biting sensitivity. RESULTS: The maxillary first molar was the most prevalent (N = 25, 40%). The number of crack lines on the finish line ranged from 1 to 6 while the number of crack lines through preparation on the finish line from 0 to 4. Pain relief achieved steadily to 52% for thermal and 62% for biting at 1 week to over 90% for each by 3 months and was completely resolved (no pain) for each by 12 months. Painful of lateral percussion was related to a long period of thermal sensitivity (≥1 month) after restoration with occlusal veneer. The number of crack lines through preparation on the finish line >2 was correlated with biting sensitivity (≥1 month) post-treatment. CONCLUSIONS: Most patients (>90%) became asymptomatic of biting and thermal sensitivity within 3 months of CT restored by occlusal veneer. Lateral percussion and the number of crack lines through preparation on the finish line could be significant factors affecting postoperative symptoms. CLINICAL SIGNIFICANCE: Occlusal veneer is an ultrathin restoration and had no need for restricting clinical crown height, which could protect and relief the biting/thermal sensitivity of CT without preventive root canal therapy.

Clinical applications of a quantitative light-induced fluorescent (QLF) device in the detection and management of cracked teeth: A case report.

INTRODUCTION: The aim of this case report was to discuss the clinical application using a quantitative light-induced fluorescent (QLF) device for the diagnosis and treatment of a cracked tooth as visualizing the tooth's crack. CASE REPORT: A 39-year-old woman visited a dental hospital complaining of throbbing pain on tooth #36. Observation of the tooth with naked eyes showed that tooth had a ceramic restoration with no specific findings. QLF device's images around the restoration, and after removal of the restoration were taken. In the QLF image after removal of the restoration, clear red-fluorescent crack line was shown, indicating that microorganism had penetrated along the crack path. During root canal treatment, the QLF image of the inside of the pulp chamber showed a pattern in which the crack line progressed into the tooth. During the treatment of the cracked tooth, the crack line was removed as much as possible using the fluorescent information obtained by the QLF device, and crack lines of fluorescence images quantitatively analyzed using a QLF's software. CONCLUSION: Images acquired with the QLF device can provide useful information for detecting crack lines, recording the treatment process, and restorative management of cracked teeth.

Mechanical properties of cracked teeth with different dental materials and crown parameters: An in vitro proof-of-concept.

OBJECTIVE: This work analyzed and compared the mechanical properties of identical cracked tooth models treated with different materials and crown parameters. Thus, to provide dentists with a more structured way to select materials and geometric parameters and determine the strongest restoration model for cracked teeth. METHODS: This work used finite element analysis (FEA). We applied 25 restorative models, including five restorative materials, and three preparation parameters. Seven mechanical properties of the cracked tooth preparation were analyzed using correlation analysis. RESULTS: The highest lifetime of the cracked preparation was obtained for crowns with a 5° of polymerization, width = 0.8 mm, and a length offset of 0.2 mm. The highest lifetime was obtained with ZC crown material, but the least deformation of the cracked tip was obtained with LU material. SIGNIFICANCE: The results showed that the larger MOE material for the crown and a reasonable increase in the thickness and length of the crown is a favorable method to prevent further cracks to extend. This FEA study, thereby forming a novel basis for clinical guidance as to preparation of dental crowns applicable to cracked teeth.

Diagnostic and treatment preferences for cracked posterior teeth.

BACKGROUND: Longitudinal cracks in teeth are common and often present challenges in diagnosis and management. This study investigated the preferred diagnostic process and treatment modalities for these cracked teeth. METHODS: Dentists currently registered with Dental Board of Australia and practising within Australia were invited to complete an online Qualtrics-based survey on their perspectives on the presentations, diagnosis, and treatment preferences for cracked teeth. RESULTS: Of respondents, 56.8% chose to place an indirect cuspal-coverage restoration on an asymptomatic cracked vital tooth. When the tooth was mildly cold sensitive, direct cuspal-coverage restoration was favoured (64.9%), while 36.8% preferred placing an orthodontic band in a tooth with biting pain. Respondents had higher odds of recommending indirect restoration when CAD-CAM milling was available on-site or magnification was routinely used, regardless of presenting symptoms. Almost half (46.8%) preferred to extract if the tooth undergoing root canal treatment had a crack with a 5 mm probing pocket depth. Most (71.4%) demonstrated a poor understanding of cracked tooth biomechanics. CONCLUSION: Australian dentists varied in their diagnostic and treatment preferences for cracked teeth, reflecting a need for more well-controlled clinical studies in the diagnostic process, clinical biomechanics and treatment modalities for these teeth. © 2023 Australian Dental Association.

Biomechanical perspectives on dentine cracks and fractures: Implications in their clinical management.

OBJECTIVES: The present review discussed the biomechanical properties of cracks and fractures in crown and root dentine and attempted to explain why cracked teeth and vertical root fractures are so frequent despite the existence of multiple crack toughening mechanisms in dentine. The implications of this knowledge were used to justify how these defects are managed clinically. DATA, SOURCES AND STUDY SELECTION: Literature search was conducted on PubMed, Web of Science, and Scopus for a narrative review on fracture mechanics of crown and root dentine as well as the clinical management of cracked teeth and teeth with vertical root fracture. CONCLUSIONS: Although dentine is tougher and less brittle than enamel, it's facture toughness is considerably lower than most ductile metals. Because the initiation toughness of dentine is very low, cracks initiate from incipient damage under low stress While crack toughening mechanisms exist that enable dentine to resist crack extension, these mechanisms are often inadequate for protecting dentine from crack propagation that ultimately leads to catastrophic failure. Additional factors such as ageing also reduces the resistance of dentine to crack growth. Because dentine cracks are eventually filled with bacteria biofilms upon exposure to oral fluids, they enable rapid bacteria ingress into the dental pulp via open dentinal tubules. To date, treatment options for cracked teeth are limited. While most teeth with vertical root fracture are recommended for extraction, new strategies have been reported that appeared to achieve short-term success in preserving these teeth. CLINICAL SIGNIFICANCE: Current strategies for the management for dentine cracks and fractures are limited and their long-term effectiveness remain uncertain. Understanding the characteristics, toughening mechanism and weakening factors of tooth cracks is helpful in designing better treatment.

Lessons learned from the Cracked Tooth Registry: A 3-year clinical study in the Nation's Network.

BACKGROUND: This article reviews the most salient lessons learned from a large, multisite, 3-year observational study of posterior teeth with cracks conducted by The National Dental Practice-Based Research Network. TYPES OF STUDIES REVIEWED: Eight articles published over a 6-year period (2017-2022) describing clinical characteristics of posterior teeth with cracks and their treatment and outcomes are reviewed and discussed to answer 3 common questions faced by oral health care clinicians: Which cracked teeth will get worse? When should practitioners intervene? What is the best treatment? RESULTS: Although cracks in teeth are prevalent, few will fracture (3%) or show crack progression in 3 years (12%). Characteristics that guide the clinician to treatment include active caries, biting pain, and to a lesser degree, having a crack detectable with an explorer, connecting with a restoration, or blocking transilluminated light; the main treatment chosen is a complete crown. Of those teeth treated (36%), few (14%) will need retreatment but will still survive, despite having an internal crack as well. CONCLUSIONS AND PRACTICAL IMPLICATIONS: Although cracked teeth often pose a dilemma to clinicians, clincians are generally good at deciding which teeth to treat and when and which to monitor.

Characteristics of Cracked Teeth with Reversible Pulpitis After Orthodontic Banding-A Prospective Cohort Study.

INTRODUCTION: Cracked teeth with reversible pulpitis can be managed with orthodontic bands in the interim before definitive restorations. The aim of this study was to determine short-term outcomes of these teeth following orthodontic band placement. The time taken for definitive pulp diagnoses after orthodontic band placement and associated prognostic factors was also analyzed. METHODS: One hundred twenty-five patients with a cracked tooth with reversible pulpitis each were recruited. Preoperative data including patient and tooth factors were collected. Cracked teeth were banded and reviewed until symptoms resolved before referral for coronal coverage. Kaplan-Meier and Cox analyses were performed to analyze pulp survival of these teeth. Prognostic factors were investigated using Pearson's chi-square and Student's t-test. RESULTS: One hundred twenty-two cracked teeth were analyzed. One hundred thirteen (92.6%) teeth had the pulpitis resolved within 2 months (median 40.0; interquartile range 28-61). The median time taken for progression to irreversible pulpitis or pulp necrosis for teeth that required root canal treatment was 3 months (median 90.0; interquartile range 68-110). No prognostic factors were associated with the resolution of pulpal symptoms. However, higher preoperative triggered pain scores (P < .05, hazards ratio 1.547) and absence of a distal marginal ridge crack (P < .05, hazards ratio 0.638) were correlated with a longer duration before definitive pulp diagnoses. CONCLUSION: Following orthodontic band placement, a normal pulp diagnosis was achieved in 92.6% of cracked teeth with preoperative reversible pulpitis. Definitive pulp diagnoses could be determined in approximately 2 months. Teeth with higher preoperative triggered pain scores may require a longer review period.

Therapeutic strategy for cracked teeth.

The management of cracked teeth represents a difficulty because their diagnosis is complex and there is no consensus concerning their treatment. The present article explains this pathology within enamel and dentin and also focuses on the clinical consequences of crack development in dental tissue. As cracks have both biologic and mechanical implications, a complete review of the literature on the subject has enabled the development of a comprehensive diagnostic approach to identify cracked teeth and optimize their management. The elements of diagnosis are the bite test, transillumination, the pulp sensitivity test, the periodontal test, radiologic examinations, removal of existing restorations, and the use of quantitative light-induced fluorescence. Finally, the management of biologic and mechanical imperatives relating to the treatment of cracked teeth has allowed the proposal of a reliable and reproducible therapeutic strategy based on two pillars: the arrest of bacterial infiltration using immediate dentin sealing, and the limitation of crack propagation using relative cuspal coverage. In this article, the proposed clinical protocol is explained through the use of a decision map and is illustrated by a clinical case example.

Was the Coronavirus Disease 2019 Pandemic Associated with an Increased Rate of Cracked Teeth?

INTRODUCTION: There is lack of data on whether the coronavirus disease 2019 (COVID-19) pandemic was associated with changes in the etiology of pathosis in endodontic patients. The aim of this study was to determine the rate of cracks and other etiologic factors during the period of March 16th to May 31st in 2020 (COVID-19 initial outbreak) and 2021 (COVID-19 ongoing pandemic) compared with figures from the same period in 2019 (pre-COVID era) in 2 endodontists' practices. METHODS: The etiologies of patients' chief complaints were determined from records of 2440 teeth (740 in 2019, 651 in 2020, and 1049 in 2021). Changes in the proportion of etiologic factors among all 3 periods were analyzed. The association between the rate of cracked teeth and patients' age and sex was determined using a logistic regression model. RESULTS: The rates of all etiologies collectively during the studied periods showed a significant change (P < .0001). The rate of cracks significantly increased in 2020 (11.8%) (P = .0001) and 2021 (8%) (P = .0018) compared with 2019 (4.3%). The rate of persistent infections decreased in 2020 (22.3%) (P = .0013) and then increased in 2021 (27.5%) (P = .0153) compared with 2019 (30%). Cracked teeth were associated with the age group of 40-60 years (odds ratio [OR] = 1.882; 95% confidence interval [CI], 1.063-3.330) in 2020 and with age ranges of 40-60 years (OR = 2.051; 95% CI, 1.120-3.759) and >60 years (OR = 2.038; 95% CI, 1.050-3.956) and male sex (OR = 1.599; 95% CI, 1.019-2.510) in 2021. CONCLUSIONS: The rate of cracked teeth increased during the initial outbreak of the COVID-19 pandemic and 1 year later. This study provided evidence on the association between the COVID-19 pandemic and changes in the rate and presentation of endodontic etiologic factors.

Treatment of cracked teeth: A comprehensive narrative review.

OBJECTIVES: The term "cracked tooth" is used to describe an incomplete fracture initiated from the crown and progressing towards a subgingival direction. Despite the high prevalence of cracked teeth and their frequent association with symptoms and pulpal or periapical pathoses, there is still no consensus in the literature with regard to their restorative and endodontic management. Therefore, the aim of this narrative review was to evaluate the most relevant research and provide an up-to-date comprehensive overview regarding the treatment of cracked teeth. MATERIALS AND METHODS: An electronic literature search was carried out in MEDLINE (via Ovid), Embase (via Ovid), Scopus, and Web of Science as well as several "Grey literature" sources up to February 22nd 2022 using a combination of pre-specified 'free-text' terms (keywords) and "subject headings." The search process was supplemented by handsearching in relevant dental journals and reference lists. This narrative review focused on clinical follow-up studies (observational or interventional studies, case series/reports), laboratory studies and systematic reviews written in English language that reported data on treatment of permanent cracked teeth. The selection of relevant studies was carried out by two reviewers (AK and DG) working independently in two consecutive stages: title/abstract screening and full-text retrieval. Any discrepancies in the study selection were resolved by discussion between the reviewers. RESULTS: In total, 64 articles were selected for inclusion in this narrative review. CONCLUSIONS: Cracked teeth with normal pulp or reversible pulpitis have exhibited high pulp and tooth survival rates by the provision of direct or indirect composite restorations. Besides, recent data favour monitoring, especially in the absence of symptoms or compromised tooth structure. When endodontic intervention is required, current evidence suggests that along with appropriate restorative management, outcomes of cracked teeth may be comparable to those of non-cracked root filled teeth.

A perspective on the diagnosis of cracked tooth: imaging modalities evolve to AI-based analysis.

Despite numerous clinical trials and pre-clinical developments, the diagnosis of cracked tooth, especially in the early stages, remains a challenge. Cracked tooth syndrome is often accompanied by dramatic painful responses from occlusion and temperature stimulation, which has become one of the leading causes for tooth loss in adults. Current clinical diagnostical approaches for cracked tooth have been widely investigated based on X-rays, optical light, ultrasound wave, etc. Advances in artificial intelligence (AI) development have unlocked the possibility of detecting the crack in a more intellectual and automotive way. This may lead to the possibility of further enhancement of the diagnostic accuracy for cracked tooth disease. In this review, various medical imaging technologies for diagnosing cracked tooth are overviewed. In particular, the imaging modality, effect and the advantages of each diagnostic technique are discussed. What's more, AI-based crack detection and classification methods, especially the convolutional neural network (CNN)-based algorithms, including image classification (AlexNet), object detection (YOLO, Faster-RCNN), semantic segmentation (U-Net, Segnet) are comprehensively reviewed. Finally, the future perspectives and challenges in the diagnosis of the cracked tooth are lighted.