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.

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.

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.

Evaluation of the clinical efficacy of quantitative light-induced fluorescence technology in diagnosing cracked teeth

BACKGROUND

This retrospective study evaluated the clinical efficacy of quantitative light-induced fluorescence (QLF) technology for crack detection and the diagnosis of cracked teeth and assessed the possibility of a quantitative evaluation of cracks using QLF technology.

METHODS

Patients who were clinically diagnosed with cracked teeth over a 1-year period were included. The QLF images of the corresponding symptomatic cracked teeth and asymptomatic contralateral teeth with crack lines were taken with Qraypen C (AIOBIO, Seoul, Korea). Fluorescence loss (ΔF), maximum fluorescence loss (ΔFmax), red fluorescence (ΔR), and maximum red fluorescence (ΔRmax) of the crack line were analyzed. The correlation between these parameters and sex, age, tooth position (1st premolar, 2nd premolar, 1st molar, 2nd molar), spontaneous pain (+/-), percussion test (+/-), cold test (++/+/-), and bite test (+/-) were statistically analyzed.

RESULTS

A total of 66 patients were included. Twenty-four patients had asymptomatic contralateral teeth with apparent crack lines; thus, 90 teeth were analyzed. The crack lines in 84 teeth observed as red fluorescent lines on the QLF images showed ΔR values higher than the cut-off value set by the analysis program used. The patient's age and the ∣ΔF∣ and ΔR values were positively correlated. However, there was no statistically significant difference in the QLF parameters between the same patient's symptomatic tooth and the contralateral tooth.

CONCLUSIONS

QLF technology is a useful assistive diagnostic device for diagnosing cracked teeth.

CBCT Patterns of Bone Loss and Clinical Predictors for the Diagnosis of Cracked Teeth and Teeth with Vertical Root Fracture

AIM

This study aimed to identify clinical and radiographic characteristics of teeth with longitudinal fractures to assist in the diagnosis and differentiation between cracked teeth and teeth with vertical root fracture (VRF).

METHODS

Ninety-five patients (95 teeth) diagnosed with a longitudinal fracture (only cracked teeth or VRF) through clinical visualization of the fracture line were included in this study. Clinical and radiographic data were collected from the patients' record to identify the characteristics associated with each condition. Fifty-four patients (54 teeth) had full radiographic [periapical radiograph (PA) and cone-beam computed tomography scan (CBCT)] and clinical findings (probing depths and clinical images of the fracture line). PA and CBCT images were evaluated by two independent examiners to identify the different patterns of bone loss associated with these teeth (no defect, angular defect, J-shaped defect, combined defect). Cohen Kappa analysis was used to compare the results between the two examiners and between the findings of the PA and the CBCT. Pearson's chi-square analysis, fisher exact test, and Adjusted Bonferroni post Hoc testing were used to establish an association between the type and extension of the longitudinal fracture with the probing depth, the CBCT pattern of bony defects, and the presence/absence of the buccal plate. Also, to compare the clinical and radiographic characteristics of cracked teeth and teeth with VRF (P<0.05).

RESULTS

CBCT images had 4.4 times the odds of detecting bony defects suggestive of longitudinal fractures compared to PA. Teeth with VRF were more associated with indirect restorations, deep probing (>6mm), absence of the cortical plate and a J-shaped defect on the CBCT (P<0.05). Cracked teeth, on the other hand, were associated with direct restorations, shallow probing (<6mm), intact cortical plate, and the presence of an angular defect on the CBCT (P<0.001). There was a significant correlation between a radicular extension of the fracture line and deep probing, as well as J-shaped defects (P<0.05).

CONCLUSION

Patterns of bone loss on the CBCT can likely differentiate between cracked teeth and teeth with VRF. The presence of an angular defect may suggest the presence of a crack in the tooth prior to intervention. J-shaped defects, deep probing (>6mm), and loss of the cortical plate are likely suggestive of VRF.

A method of crack detection based on digital image correlation for simulated cracked tooth

Background

Early clinical cracked tooth can be a perplexing disorder to diagnose and manage. One of the key problems for the diagnosis of the cracked tooth is the detection of the location of the surface crack.

Methods

This paper proposes an image-based method for the detection of the micro-crack in the simulated cracked tooth. A homemade three-axis motion platform mounted with a telecentric lens was built as an image acquisition system to observe the surface of the simulated cracked tooth, which was under compression with a magnitude of the masticatory force. By using digital image correlation (DIC), the deformation map for the crown surface of the cracked tooth was calculated. Through image analysis, the micro-crack was quantitatively visualized and characterized.

Results

The skeleton of the crack path was successfully extracted from the image of the principal strain field, which was further verified by the image from micro-CT. Based on crack kinematics, the crack opening displacement was quantitatively calculated to be 2–10 µm under the normal mastication stress, which was in good agreement with the value reported in the literature.

Conclusions

The crack on the surface of the simulated cracked tooth could be detected based on the proposed DIC-based method. The proposed method may provide a new solution for the rapid clinical diagnosis of cracked teeth and the calculated crack information would be helpful for the subsequent clinical treatment of cracked teeth.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12903-021-01897-2.

Comparison of diagnosis of cracked tooth using contrast-enhanced CBCT and micro-CT

OBJECTIVES

To evaluate the diagnostic accuracy using sodium iodide (NaI) and dimethyl sulfoxide (DMSO) as contrast agent in cone beam computed tomography (CBCT) scanning, and compare this with micro-CT.

METHODS

18 teeth were cracked artificially by soaking them cyclically in liquid nitrogen and hot water. After pre-treatment with artificial saliva, the teeth were scanned in four modes: CBCT routine scanning without contrast agent (RS); CBCT with meglumine diatrizoate (MD) as contrast agent (ES1); CBCT with NaI + DMSO as contrast agent (ES2); and micro-CT (mCT). The number of crack lines was evaluated in all four modes. Depth of crack lines and number of cracks presented from the occlusal surface to the pulp cavity (Np) in ES2 and micro-CT images were evaluated.

RESULTS

There were 63 crack lines in all 18 teeth. 45 crack lines were visible on ES2 images as against four on the RS and ES1 images (p<0.05) and 37 on micro-CT images (p>0.05). Further, 34 crack lines could be observed on both ES2 and micro-CT images, and the average depth presented on ES2 images was 4.56 ± 0.88 mm and 3.89 ± 1.08 mm on micro-CT images (p<0.05). More crack lines could be detected from the occlusal surface to the pulp cavity on ES2 images than on micro-CT images (22 vs 11).

CONCLUSION

CBCT with NaI +DMSO as the contrast agent was equivalent to micro-CT for number of crack lines and better for depth of crack lines. NaI + DMSO could be a potential CBCT contrast agent to improve diagnostic accuracy for cracked tooth.

The Effectiveness of a Quantitative Light-induced Fluorescent Device for the Diagnosis of a Cracked Tooth: A Case Report

Diagnosing a cracked tooth is a challenge for dental clinicians. This report describes the use of a quantitative light-induced fluorescent (QLF) device that detects fluorescence reactions with visible light (405 nm) to visually identify microscopic tooth cracks during the diagnosis and treatment of cracked teeth that caused pulp disease. Fluorescence images of the occlusal surface, before and after removal of the restoration, and inside of the access cavity for root canal treatment were obtained using an intraoral capture-type QLF device (Q-ray penC; AIOBIO, Seoul, Korea). The device provided visual information such as enhanced magnification and fluorescent images to identify cracks on the exterior of the tooth, around restorations, and inside the cavity after removal of the restoration by a simple image capture process. The device was able to demonstrate the existence of the crack line and to predict the depth of cracks during treatment.The QLF device showed a potential benefit in the diagnosis and characterization, including the location and depth, of tooth cracks.

Oral Functional Behaviors and Tooth Factors Associated with Cracked Teeth in Asymptomatic Patients

INTRODUCTION

A cracked tooth may occur due to excessive applied force or tooth weakness. However, there is scant information concerning the cracked tooth risk factors. This study aimed to explore the oral functional behaviors and tooth factors associated with posterior cracked teeth.

METHODS

Fifty-six patients underwent their oral functional behavior assessment via a questionnaire. The intraoral parameters at the patient level (remaining teeth, occluding tooth pairs, overbite, overjet, and occlusal guidance type) and tooth level (remaining marginal ridge number, restored surface number, restorative materials, and cuspal inclination) were examined. The posterior teeth were stained with methylene blue dye and inspected for cracks using a microscope. The correlations between each patient-level parameter and the cracked tooth number/subject were determined using linear regression analysis. The cracked teeth were matched with their contralateral noncracked teeth, and binary regression analysis was used to analyze the association between tooth-level parameters and a cracked tooth. Multivariate regression analysis was performed if more than 1 parameter had a P value ≤.1.

RESULTS

One hundred thirty-five cracked teeth were found. Eating hard food was significantly related to the cracked tooth number (P < .05). In molars, the occlusal surface restoration and cuspal inclination were significantly related to a cracked tooth, except the mesiobuccal cusp. In the multivariate analysis, the distolingual cusp inclination significantly predicted a cracked tooth (P < .05). In premolars, the lingual cusp inclination was associated with a cracked tooth (P < .05).

CONCLUSIONS

Eating hard food, occlusal surface restoration, and steep cuspal inclination were associated with posterior cracked teeth.

Cracked teeth: Distribution and survival at 6 months, 1 year and 2 years after treatment

BACKGROUND/PURPOSE

The unpredictable condition of cracked teeth warrants further investigation and clinical experiences. The purpose of this study was to collect and record data on demographics, clinical characteristics, different treatment modalities and survival of cracked teeth at 6-month, 1-year and 2-year recalls.

METHODS

77 cracked teeth from 65 patients were included. Data on demographics, clinical parameters, treatment modalities and recall were collected. Binomial, multinomial and chi square tests were used for statistical analysis.

RESULTS

Most cracked teeth occurred in patients greater than 40 years old (p < 0.01). Cracked teeth themselves were most often molars (79.22%; p < 0.01), a non-terminal tooth in the arch (62.34%; p < 0.05) and nonendodontically-treated teeth (94.81%; p < 0.01). Cracked teeth exhibited pain to percussion (63.64%, p < 0.05) or biting (74.03%; p < 0.01), and no or only positive mobility (76.62%; p < 0.01). Cracks were most often oriented in the mesiodistal direction (68.83%; p < 0.01). Higher survival rates were noted in cracked teeth lacking pre-operative pain to palpation or spontaneous pain, and with no or only positive mobility at 6-month and 1-year recalls. In vital cracked teeth, higher survival rates were noted in teeth lacking pre-operative pain to palpation and with no or only positive mobility at 2-year recalls.

CONCLUSION

The absence of pre-operative palpation discomfort, spontaneous pain and minimal mobility, as well as the presence of pulp vitality were associated with higher survival rates of cracked teeth at all recall times. Results are useful for diagnosis and outcomes-based treatment planning of cracked teeth.

Occlusal stress distribution and remaining crack propagation of a cracked tooth treated with different materials and designs: 3D finite element analysis

OBJECTIVE

Here we used 3D finite element analysis (FEA) to analyze and directly compare stress distribution and crack propagation in identical cracked tooth models after treatment with various materials and designs.

METHODS

A 3D model of a cracked tooth was generated. We then applied eight restoration models, comprising combinations of three kinds of restoration designs (inlay, onlay, and crown) and four types of restoration materials (direct composite resin, indirect composite resin, ceramic, and gold). A 1000-N occlusal load was applied on the three reference points of the ball-shaped part in the direction of the longitudinal axis, causing crack line separation in the buccolingual direction. Stress distribution was analyzed on the occlusal surface, bottom level of the restoration, and mesiodistal longitudinal section. The stress on the lower margin of the crack surface was measured at 15 points on each model.

RESULTS

Ceramic inlay and onlay showed stress concentration at the restoration bottom, and low stress on the lower margin of the crack surface. Direct and indirect resin restorations exhibited low stress on the restoration bottom, and high stress on the proximal end of the lower margin of the crack surface. With a resin-unfilled gold crown, stress was concentrated on the crown bottom and the lower margin of the crack surface. Direct resin filling inside the gold crown yielded significantly decreased stress on both areas.

SIGNIFICANCE

Our results suggest that inlay and onlay ceramic restorations, and gold crown with resin filling inside, are advantageous methods for preventing further crack propagation.

Diagnosis and management of cracked tooth by quantitative light-induced fluorescence technology

INTRODUCTION

The aim of this case report was to describe the process of diagnosis and treatment of a cracked tooth using quantitative light-induced fluorescence (QLF).

CASE REPORT

A 43-year-old male presented at our dental clinic with a complaint of cold pain in #17 tooth. A routine oral examination with radiography was performed for evaluation of the oral condition and treatment planning. Additionally, QLF image capture was performed using Qraycam and Qraypen (AIOBIO, Seoul, Republic of Korea), to collect white-light and fluorescence images. The #17 tooth was observed to have a crack line, showing red fluorescence, from the distal to mesial aspect on the occlusal surface. Even though there was no visible root fracture in the radiographic image, bone loss was observed. Therefore, we performed periodontal treatment. One month later, a root canal treatment was performed because the patient still complained of pain in the #17 tooth. During this treatment, one fluorescent image and one white light image set was captured with the Qraypen. A crack line showing red fluorescence was observed, while the line was not visible to the naked eye. After treatment, the patient has had no complaint related to this tooth for 3 years until today.

CONCLUSIONS

Clinically, use of QLF confirmed the presence of a crack before and during a root canal treatment. Therefore, it is postulated that the QLF technology could objectively facilitate the diagnosis and treatment of a cracked tooth.

Treatment Decision-making of Cracked Teeth: Survey of American Endodontists

AIM

The aim of this study is to survey the opinion of endodontists in the United States regarding their approach to treatment of cracked teeth.

MATERIALS AND METHODS

A survey assessing the opinions of 3,500 endodontists in the United States was administered over a 4-week period. It consisted of a hypothetical clinical case and eight different treatment scenarios. Participants were asked to select one of the two treatment options: (A) informing the patient of the presence of a crack, reinforcing the tooth, and continuing with endodontic treatment; and (B) extraction of the tooth followed by replacement with an implant supported crown or fixed partial denture.

RESULTS

When the crack extended across the distal marginal ridge with no associated probing depths, 92.65% endodontists preferred to continue with endodontic treatment and reenforcing the tooth. When the crack extended across the distal marginal ridge and was associated with a probing depth of 6 mm, 80% preferred extraction of the tooth. When the crack extended across the mesial marginal ridge up to the orifice of the mesiolingual canal with no associated probing depth, 82.78% preferred to continue with the treatment. When the crack was associated with a 6-mm probing depth, 83.79% preferred tooth extraction. When the crack extended across the mesial marginal ridge and down into the mesiolingual canal with/without associated probing depth, 91.13% and 63.54% preferred tooth extraction, respectively. When the crack involved both mesial and distal marginal ridges and extended across the pulp chamber, 79.74% preferred tooth extraction. When a split tooth was presented, 98.48% preferred tooth extraction.

CONCLUSION

It appears that the presence of a 6-mm periodontal pocket is considered an important factor by most American endodontists when deciding whether to preserve the cracked tooth or extract it.

CLINICAL SIGNIFICANCE

There is no consensus among dentists regarding the best approach to treat cracked teeth. Conclusive studies evaluating clinical approaches of endodontists regarding treatment of cracked teeth are lacking. Therefore, surveyed opinion of endodontists in the United States regarding their approach to treatment of cracked teeth was done to try to reach the best clinical decision regarding this dilemma.

Associations of types of pain with crack-level, tooth-level and patient-level characteristics in posterior teeth with visible cracks: Findings from the National Dental Practice-Based Research Network

OBJECTIVES

The objective of this study was to determine which patient traits, behaviors, external tooth and/or crack characteristics correlate with the types of symptoms that teeth with visible cracks exhibit, namely pain on biting, pain due to cold stimuli, or spontaneous pain.

METHODS

Dentists in the National Dental Practice-Based Research Network enrolled a convenience sample of subjects each of whom had a single, vital posterior tooth with at least one observable external crack (cracked teeth); 2858 cracked teeth from 209 practitioners were enrolled. Data were collected at the patient-, tooth-, and crack-level. Generalized estimating equations were used to obtain significant (p < .05) independent odds ratios (OR) associated with teeth that were painful for 10 outcomes based on types of pain and combinations thereof.

RESULTS

Overall, 45% of cracked teeth had one or more symptoms. Pain to cold was the most common symptom, which occurred in 37% of cracked teeth. Pain on biting (16%) and spontaneous pain (11%) were less common. Sixty-five percent of symptomatic cracked teeth had only one type of symptom, of these 78% were painful only to cold. No patient-, tooth- or crack-level characteristic was significantly associated with pain to cold alone. Positive associations for various combinations of pain symptoms were present with cracks that: (1) were on molars; (2) were in occlusion; (3) had a wear facet through enamel; (4) had caries; (5) were evident on a radiograph; (6) ran in more than one direction; (7) blocked transilluminated light; (8) connected with another crack; (9) extended onto the root; (10) extended in more than one direction; or (11) were on the distal surface. Persons who were <65 yo or who clench, grind, or press their teeth together also were more likely to have pain symptoms. Pain was less likely in teeth with stained cracks or exposed roots, or in non-Hispanic whites.

CONCLUSIONS

Although pain to cold was the most commonly noted pain associated with symptomatic cracked teeth, no patient-, tooth- or crack-level characteristic was significantly associated with pain to cold alone. Characteristics were only associated with pain on biting and/or spontaneous pain with or without pain to cold.

CLINICAL SIGNIFICANCE

Although often considered the most reliable diagnosis for a cracked tooth, pain on biting is not the most common symptom of a tooth with a visible crack, but rather pain to cold.

Novel Matricing Technique for Management of Fractured Cusp Conundrum - A Clinician's Corner

Longitudinal tooth fracture can be classified as craze lines, fractured cusp, cracked tooth, split tooth and vertical root fracture based on extent and severity of the fracture line. The most common type of longitudinal tooth fracture is fractured cusp that poses the treatment dilemma. Retention of the fractured cusp segment temporarily with matrix band followed by permanent bonded restoration and finally removal of tooth fragment during crown preparation is a novel technique. This paper throws light on a matricing and holding technique for the management of supra-crestally fractured palatal cusp of maxillary first premolar in a 29-year-old Asian male.

A temporary filling material during endodontic treatment may cause tooth fractures in two-surface class II cavities in vitro

OBJECTIVES

To investigate the effect of a zinc oxide/zinc sulphate-based cement as a temporary filling material during root canal treatment on the occurrence of cracks within the filling material or the tooth.

MATERIALS AND METHODS

Root canals of 122 extracted human molars were prepared using ProTaper instruments. Standardized occlusal-distal cavities were prepared. After placing calcium hydroxide into the root canals, the teeth were divided randomly into four groups containing 33 specimens each. In the Coltosol group, the cavity was completely filled with Coltosol® F. In the Coltosol-Clearfil group, a 2-mm layer of Coltosol® F was placed into the apical part of the pulp chamber, and in the Clearfil group, a foam pellet was placed into the coronal pulp chamber. The remaining cavities were filled with Clearfil™. In the control group, the cavities were not restored. The teeth were stored at 37 °C for 14 days and examined every 24 h under a stereomicroscope.

RESULTS

Fractures of the filling and/or the tooth were only observed in the Coltosol group. All Coltosol® F restorations had cracks after 24 h. Tooth fractures were found in 25 (76 %) teeth. Among these teeth, 21 (84 %) had crown fractures, four (16 %) had root-crown fractures. All root-crown fractures were vertical.

CONCLUSION

Coltosol® F when used alone led to tooth fractures in two-surface class II cavities in teeth undergoing root canal treatment.

CLINICAL RELEVANCE

Coltosol® F solely used as restorative material may lead to tooth fractures in two-surface class II cavities.