Treatment of Cracked Teeth

Insights into Predicting Tooth Extraction from Panoramic Dental Images: Artificial Intelligence vs. Dentists

OBJECTIVES

Tooth extraction is one of the most frequently performed medical procedures. The indication is based on the combination of clinical and radiological examination and individual patient parameters and should be made with great care. However, determining whether a tooth should be extracted is not always a straightforward decision. Moreover, visual and cognitive pitfalls in the analysis of radiographs may lead to incorrect decisions. Artificial intelligence (AI) could be used as a decision support tool to provide a score of tooth extractability.

MATERIAL AND METHODS

Using 26,956 single teeth images from 1,184 panoramic radiographs (PANs), we trained a ResNet50 network to classify teeth as either extraction-worthy or preservable. For this purpose, teeth were cropped with different margins from PANs and annotated. The usefulness of the AI-based classification as well that of dentists was evaluated on a test dataset. In addition, the explainability of the best AI model was visualized via a class activation mapping using CAMERAS.

RESULTS

The ROC-AUC for the best AI model to discriminate teeth worthy of preservation was 0.901 with 2% margin on dental images. In contrast, the average ROC-AUC for dentists was only 0.797. With a 19.1% tooth extractions prevalence, the AI model's PR-AUC was 0.749, while the dentist evaluation only reached 0.589.

CONCLUSION

AI models outperform dentists/specialists in predicting tooth extraction based solely on X-ray images, while the AI performance improves with increasing contextual information.

CLINICAL RELEVANCE

AI could help monitor at-risk teeth and reduce errors in indications for extractions.

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.

The exploration of a compound cone-beam CT contrast agent for diagnosis of human extracted cracked tooth

Objectives

This study aims to investigate the use of sodium iodide (NaI), dimethyl sulfoxide (DMSO), ethyl alcohol, and ethyl acetate as cone-beam CT (CBCT) contrast agents for diagnosing cracked teeth. The optimal delay time for detecting the number of crack lines beyond the dentino-enamel junction (Nd), the number of cracks extending from the occlusal surface to the pulp cavity (Np), and the depth of the crack lines was explored.

Methods

14 human extracted cracked teeth were collected, 12 were used for enhanced scanning, and 2 were used for exploring the characteristic of crack lines. The teeth were scanned in 3 CBCT enhanced scanning (ES) modes: ES1 using meglumine diatrizoate (MD); ES2 using NaI and DMSO, ES3 using NaI, DMSO, ethyl alcohol and ethyl acetate. Three delay times (15mins, 30mins, and 60mins) were set for scanning. Nd, Np, and depth of crack lines were evaluated.

Results

There were totally 24 crack lines on 12 cracked teeth. Nd was 10 in ES1 at 60mins, 24 in ES2 at 60mins and 24 in ES3 at 15mins. Np was 1 in ES1 at 60mins, 10 in ES2 at 60mins and 21 in ES3 at 60mins, and there were significantly different among them (p < 0.01). The average depth presented on ES3 was significantly deeper than ES1 and ES2 (p < 0.01).

Conclusion

NaI, DMSO, ethyl alcohol and ethyl acetate show potential as contrast agents for enhanced CBCT scanning in diagnosis of cracked teeth and their depth in vivo. A delay time of 15 min is necessary to confirm the existence of crack lines, while a longer delay time is required to ascertain if these crack lines extend to the pulp cavity.

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.

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.

Automatic Detection of Cracks in Cracked Tooth Based on Binary Classification Convolutional Neural Networks

Cracked tooth syndrome is a commonly encountered disease in dentistry, which is often accompanied by dramatic painful responses from occlusion and temperature stimulation. Current clinical diagnostic trials include traditional methods (such as occlusion test, probing, cold stimulation, etc.) and X-rays based medical imaging (periapical radiography (PR), cone-beam computed tomography (CBCT), etc.). However, these methods are strongly dependent on the experience of the clinicians, and some inconspicuous cracks are also extremely easy to be overlooked by visual observation, which will definitely affect the subsequent treatments. Inspired by the achievements of applying deep convolutional neural networks (CNNs) in crack detection in engineering, this article proposes an image-based crack detection method using a deep CNN classifier in combination with a sliding window algorithm. A CNN model is designed by modifying the size of the input layer and adding a fully connected layer with 2 units based on the ResNet50, and then, the proposed CNN is trained and validated with a self-prepared cracked tooth dataset including 20,000 images. By comparing validation accuracy under seven different learning rates, 10⁻⁵ is chosen as the best learning rate for the following testing process. The trained CNN is tested on 100 images with 1920 × 1080-pixel resolutions, which achieves an average accuracy of 90.39%. The results show that the proposed method can effectively detect cracks in images under various conditions (stained, overexplosion, images affected by other diseases). The proposed method in this article provides doctors with a more intelligent diagnostic solution, and it is not only suitable for optical photographs but also for automated diagnosis of other medical imaging images.

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.

Review of Cracked Tooth Syndrome: Etiology, Diagnosis, Management, and Prevention

Cracked tooth syndrome refers to a series of symptoms caused by cracked teeth. This article reviews the current literature on cracked tooth syndrome from four aspects, etiology, diagnosis, management, and prevention, to provide readers integrated information about this. The article begins with an introduction to the odontiatrogenic factors and then covers the noniatrogenic factors that induce cracked tooth syndrome. While the former discusses inappropriate root canal therapy and improper restorative procedures, the latter covers the topics such as the developmental and functional status of cracked tooth syndrome. This is then followed by the description of common clinical diagnosis methods, the prospects of new technologies, and summaries of current clinical management methods, including immediate management and direct and indirect restoration. In the final section, preventive methods and their importance are proposed, with the aim of educating the common population.

Does bidirectional splinting improve outcomes in cracked teeth with reversible pulpitis?

Aim To investigate the success rate of 'bidirectional' splinting - both internal and external - of teeth with longitudinal cracks and reversible pulpitis, as well as to identify any signs or symptoms that could give a prognostic indication of success.Design Cohort study.Cohort selection Thirty-four teeth from 33 patients visiting the Department of Conservative Dentistry at the Yonsei University Dental Hospital, Seoul, South Korea, between June 2016 and November 2017, diagnosed with longitudinal cracked teeth with reversible pulpitis. Teeth with signs of pulp necrosis, irreversible pulpitis or other types of longitudinal cracks were excluded.Data analysis These teeth were treated by a systematic protocol of initial external splinting with a metal band, crack removal and internal splinting with composite resin, placement of a temporary crown, before a final permanent crown. Symptoms and vitality were assessed at every stage and root canal treatment provided where deemed necessary. The teeth were then followed up for up to four years to assess tooth survival and pulp vitality.Results Accounting for five dropouts during the treatment protocol, 29 teeth reached at least a one-year recall. Of these, 21 (72%) had pulp survival, eight (28%) had required root canal treatment - six of those before final crown cementation - and zero teeth required extraction (100% survival rate). Cracked teeth without initial tenderness to percussion showed a 94% pulp survival rate, while those with tenderness had only a 46% pulp survival rate.Conclusions A systematic approach to treating cracked teeth with reversible pulpitis should be utilised to maintain tooth vitality and survival. Using a bidirectional splinting method provides good outcomes for these teeth. Tenderness to percussion is a significant prognostic indicator of pulp vitality and whether root canal treatment should be initiated.

"THE CORRELATION OF CRACK LINES AND DEFINITIVE RESTORATIONS WITH THE SURVIVAL AND SUCCESS RATES OF CRACKED TEETH: A LONG-TERM RETROSPECTIVE CLINICAL STUDY"

INTRODUCTION

Cracked teeth (CT) frequently require protective adhesive restorations. This long-term, longitudinal retrospective clinical study aimed to evaluate the factors influencing the success and survival rates of CT with crack lines (CLs) in different directions, when restored early with onlays or full-coverage crowns.

METHODS

The dental records of 71 patients with a total of 86 CT, with different pulpal and periapical diagnoses, and with follow-ups spanning over 1-11 years were included. Data regarding the demographics; clinical symptoms and signs; bruxism; occlusal interferences; eating habits; pulpal and periapical diagnoses; number, direction, location, and extent of crack lines; probing depth; and coronary condition before and after the placement of definitive restorations were collected. Univariate associations between tooth survival and explanatory variables were assessed. The long-term survival rate was estimated using the Kaplan-Meier analysis and the log-rank test. A multivariate analysis was performed using Cox regression analysis.

RESULTS

The overall success rate was 93.0%, and the overall survival estimates of CT restored early were 98.6%, 94.9% and 55.9% at the 1-, 5-, and 11-year follow-ups, respectively. The direction of the CLs did not influence the survival of the tooth. No significant association was observed between the type of tooth, probing depth, root canal treatment (RCT), and tooth loss (P>0.05). The multivariate analysis showed that previously treated CT (P<0.05), provision of onlay restorations (P<0.05), and placement of posts (P<0.05) had higher correlations with tooth loss. Additionally, placement of full-coverage crowns resulted in lower tooth loss compared with the placement of onlays (P<0.05).

CONCLUSION

Previous endodontic treatment in teeth that subsequently develop CLs has a negative impact on the survival rate of the teeth. Moreover, early placement of full-coverage crowns should be implemented for CT, regardless of the direction or number of CLs, since it is associated with a higher cracked tooth survival rate.

Association between masticatory muscle activity and oral conditions in young female college students

The purpose of this study was to determine the characteristics of masticatory muscle activity and various oral condition factors, and to analyze their associations in order to improve the prevention and diagnosis of masticatory muscle-related diseases. This study included 30 Korean females (mean age of 20 years, age range of 19-21 years). Participants were instructed to complete a self-written questionnaire on factors that may affect their muscle activity. Surface electromyography was used to measure the activity of the masseter and temporalis muscles. We also observed the buccal mucosa ridge, tongue indentation, tooth cracks and fractures, and mandibular tori in the oral cavity. Spearman correlation analysis and the nonparametric Mann-Whitney U test were applied to the data. When subjects had temporomandibular disorder, the right temporalis muscle exhibited significantly lower activity (P<0.05). Those who had received orthodontic treatment within the previous 2 years showed significantly lower activity of the left masseter muscle (P<0.05). Those who had a left buccal mucosa ridge exhibited lower activity of the left masseter muscle and higher activity of the right temporalis muscle compared with those without such a ridge (P<0.05). Participants with no tongue indentation showed significantly higher activity in the left masseter muscle (P<0.05). These results indicate that there are relationships between masticatory muscle activity and various factors related to the oral condition.

Effect of Root Canal Therapy Combined with Full Crown Restoration on the Level of Inflammatory Factors and Chewing Function in Patients with Cracked Teeth and Chronic Pulpitis

Objective

To explore the clinical effect of root canal therapy combined with full crown restoration in patients with cracked teeth and chronic pulpitis.

Methods

From May 2018 to June 2020, 87 patients with cracked teeth and chronic pulpitis in our hospital were selected; the patients were randomly divided into the control group and the research group by random number method. The control group only used root canal therapy; the research group used root canal therapy combined with full crown restoration. The therapeutic effect, levels of inflammatory factors, chewing function, periodontal index, complications, and quality of life were compared between the two groups.

Results

The total effective rate of the research group (97.78%) was better than the total effective rate of the control group (85.71%) (P < 0.05). Compared with before treatment, the serum levels of interleukin-1β (IL-1β), IL-6, and C-reactive protein (CRP) of the two groups of patients decreased after treatment. After treatment, compared with the control group, the serum levels of IL-1β, IL-6, and CRP in the research group decreased (P < 0.05). Compared with before treatment, the bite force of teeth and chewing efficiency of the two groups of patients increased after treatment. After treatment, compared with the control group, the bite force of teeth and chewing efficiency of the research group increased (P < 0.05). Compared with before treatment, the plaque index (PLI), probing depth (PD), gingival sulcus bleeding index (BI), and gingival index (GI) of the two groups of patients decreased after treatment. After treatment, compared with the control group, the PLI, PD, BI, and GI of the research group decreased (P < 0.05). The total incidence of complications in the research group was (11.11%), and the total incidence of complications in the control group was (16.67%); there was no significant difference between the two groups (P > 0.05). After treatment, compared with the control group, the quality of life scores of the patients in the research group were reduced (P < 0.05).

Conclusion

Root canal therapy and full crown restoration have a definite curative effect in patients with cracked teeth and chronic pulpitis, which can improve the inflammatory response, restore chewing function, maintain periodontal health, improve the quality of life, and do not increase the incidence of complications, so it has good application value.

Management of Cracked Teeth: Perspectives of General Dental Practitioners and Specialists

OBJECTIVES

The main aim of this study was to compare how general dental practitioners (GDPs), endodontists and prosthodontists diagnose, prognosticate, and treat cracked teeth. The secondary aim was to highlight factors influencing GDPs' referral practices of cracked teeth to specialists.

MATERIALS AND METHODS

Questionnaires were used to collect information from GDPs, prosthodontists, and endodontists, on their use of diagnostic methods to identify cracked teeth, prognostication, and their management and referral practices for cracked teeth. Descriptive statistics were used to summarize the quantitative data. Pearson's Chi-Square test or Fisher's Exact test was applied to categorical variables while Kruskal-Wallis or Spearman's correlation coefficient was applied to continuous variables (p <0.05). Content analysis was performed for qualitative data.

RESULTS

207 dentists responded, resulting in a response rate of 83.5%. Endodontists used more diagnostic tools as compared to prosthodontists and GDPs. For pulpally involved cracked teeth, endodontists were more likely to recommend root canal treatment (RCT) and cuspal coverage compared to extraction, followed by prosthodontists then GDPs. Main reasons for referral of cracked teeth to specialists include uncertainty in diagnosis, difficulty in crack visualization after endodontic access, and cracked teeth indicated for RCT.

CONCLUSION

GDPs, prosthodontists, and endodontists differ in terms of their diagnosis, prognostication, and treatment of cracked teeth. GDPs refer cracked teeth to specialists due to challenges faced in diagnosis and treatment. Future research and education are required to provide evidence-based guidelines in the management of cracked teeth so that patients with cracked teeth can receive standardized care.

Survival and prognostic factors of managing cracked teeth with reversible pulpitis: A 1- to 4-year prospective cohort study

AIM

This prospective clinical study evaluated the clinical performance of managing cracked teeth with reversible pulpitis through a combination of internal and external splinting and investigated factors that can affect pulp survival after splinting.

METHODOLOGY

Thirty-four teeth diagnosed with cracks and reversible pulpitis were enrolled and treated with bidirectional crack splinting: 1) immediate splinting with a stainless-steel band, 2) internal splinting with crack line removal and resin filling and 3) external splinting with a temporary crown followed by final crown placement. If the symptoms remained/recurred, root canal treatment was performed. Patients were followed up at 3, 6 and 12 months, then annually thereafter. Kaplan-Meier survival analysis to calculate the survival of the treated teeth and Cox univariate proportional hazards regression model to investigate prognostic factors were performed.

RESULTS

Twenty-nine (97%) teeth were followed up for up to 4 years. The pulp survival rate was 72% after banding and 91% after final crown cementation. No tooth was extracted (100% tooth survival rate). In the univariate Cox proportional hazard test, pain on percussion was the only statistically significant factor (hazard ratio = 11.77). Teeth with pain on percussion at the first visit had a pulp survival rate of 46% during the follow-up period. In comparison, their counterparts without pain had a 94% pulp survival rate.

CONCLUSIONS

Bidirectional splinting successfully managed cracked teeth with reversible pulpitis. Pain on percussion (mechanical allodynia) may be an important factor in deciding whether to attempt root canal treatment on symptomatic cracked teeth. A step-by-step approach with bidirectional crack splinting should be encouraged for a cracked tooth with a vital pulp without mechanical allodynia rather than pre-emptive root canal treatment.

Laboratory simulation of longitudinally cracked teeth using the step-stress cyclic loading method

AIM

To simulate in a laboratory setting longitudinal cracking in root filled premolar teeth, using cyclic mechanical fatigue.

METHODOLOGY

Mesial-occlusal-distal (MOD) cavities were prepared in twenty root filled, single-rooted, mandibular premolars restored with fibre posts and resin composites. The samples were randomly divided into two groups based on the loading approaches: static loading with a crosshead speed of 0.5 mm/min and step-stress cyclic loading (1 Hz) with increasing amplitude. The loads and numbers of cycles to failure were recorded. Micro-CT was also used to identify the fracture modes. Statistical analysis was performed using Student's t-test. The level of significance was set at 0.05.

RESULTS

The mean fracture loads for the static loading and cyclic loading groups were 769 ± 171 N and 720 ± 92 N, respectively. There was no significant difference between the two groups (P > 0.05). The proportions of longitudinal, cuspal and mixed-mode fractures under cyclic loading were 50%, 20% and 30%, respectively. Longitudinal fractures occurred with larger numbers of cycles and higher average loads per cycle compared with the other fractures. Static loading produced only cuspal fractures.

CONCLUSIONS

Longitudinally cracked premolar teeth with root fillings were successfully produced using the step-stress cyclic loading method. This provides a more clinically representative methodology for studying cracked teeth in a laboratory setting.

Symptom changes and crack progression in untreated cracked teeth: One-year findings from the National Dental Practice-Based Research Network

OBJECTIVES

The study objective was to: (1) quantify symptom (pain) and crack changes during one year of follow-up, among teeth that had at least one visible crack at baseline but which did not receive treatment for those cracks; (2) identify any patient traits/behaviors and external tooth/crack characteristics correlated with these changes.

METHODS

In this observational study, 209 National Dental Practice-Based Research Network dentists enrolled a convenience sample of 2858 subjects, each with a single, vital posterior tooth with at least one observed external crack; 1850 teeth remained untreated after one year of follow-up and were the cohort for analyses. Data were collected at the patient-, tooth-, and crack-level at baseline, one-year follow up (Y1), and interim visits. Associations between changes in symptoms and cracks were identified, as were changes in symptoms associated with baseline treatment recommendations.

RESULTS

Changes in pain symptoms were observed in 32% of patients; decreases were twice as common as increases (23% vs. 10%). More changes were observed in cold pain than in biting pain and spontaneous pain combined; 2% had increases in biting pain and 2% in spontaneous pain. Only 6% had an increase in the number of cracks. Changes in pain symptoms were not associated with an increase in the number of cracks, but were associated with baseline treatment recommendations. Specifically, pain symptom changes (especially decreases) were more common when the tooth was recommended for treatment at baseline.

CONCLUSIONS

Cracked teeth that have not received treatment one year after baseline do not show meaningful progression as measured by increased symptoms or number of cracks during follow-up.

CLINICAL SIGNIFICANCE

Untreated cracked teeth, most of which were recommended for monitoring at baseline and some of which were recommended for treatment but did not receive treatment, remained relatively stable for one year with little progression of cracks or symptoms.

Recommended treatment of cracked teeth: Results from the National Dental Practice-Based Research Network

STATEMENT OF PROBLEM

Despite the high prevalence of posterior cracked teeth, questions remain regarding the best course of action for managing these teeth.

PURPOSE

The purpose of this clinical study was to identify and quantify the characteristics of visible cracks in posterior teeth and their association with treatment recommendations among patients in the National Dental Practice-Based Research Network.

MATERIAL AND METHODS

Network dentists enrolled patients with a single, vital posterior tooth with at least 1 observable external crack. Data were collected at the patient, tooth, and crack levels, including the presence and type of pain and treatment recommendations for subject teeth. Frequencies according to treatment recommendation were obtained, and odds ratios (ORs) comparing recommendations for the tooth to be restored versus monitored were calculated. Stepwise regressions were performed using generalized models to adjust for clustering; characteristics with P<.05 were retained.

RESULTS

A total of 209 dentists enrolled 2858 patients with a posterior tooth with at least 1 crack. Mean ±standard deviation patient age was 54 ±12 years; 1813 (63%) were female, 2394 (85%) were non-Hispanic white, 2213 (77%) had some dental insurance, and 2432 (86%) had some college education. Overall, 1297 (46%) teeth caused 1 or more of the following types of pain: 1055 sensitivity to cold, 459 biting, and 367 spontaneous. A total of 1040 teeth were recommended for 1 or more treatments: restoration (n=1018; 98%), endodontics (n=29; 3%), endodontic treatment and restoration (n=20; 2%), extraction (n=2; 0.2%), and noninvasive treatment, for example, occlusal device, desensitizing (n=11; 1%). The presence of caries (OR=67.3), biting pain (OR=7.3), and evidence of a crack on radiographs (OR=5.0) were associated with over 5-fold odds of recommending restoration. Spontaneous pain was associated with nearly 3-fold odds; pain to cold, having dental insurance, a crack that was detectable with an explorer or blocked transilluminated light, or connected with a restoration were each weakly associated with increased odds of recommending a restoration (OR<2.0).

CONCLUSIONS

Approximately one-third of cracked teeth were recommended for restoration. The presence of caries, biting pain, and evidence of a crack on a radiograph were strong predictors of recommending a restoration, although the evidence of a crack on a radiograph only accounted for a 3% absolute difference (4% recommended treatment versus 1% recommended monitoring).