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.

Analysis of root canal system of maxillary first and second molars and their correlations by cone beam computed tomography.

BACKGROUND/PURPOSE: Understanding the root canal systems of molars and the association of root canal system in adjacent or contralateral molars is important for dental practice. This study aimed to use cone-beam computed tomography (CBCT) to analyze the morphology similarity of root canal systems in the maxillary first and second molars. METHODS: CBCT images of 1741 maxillary molars in a total of 519 patients were blindly examined to analyze the correlation of root canal systems between maxillary first and second molars as well as the bilateral first and second molars. RESULTS: The most common type in maxillary first molars is 3R4C (3 roots/4 canals), whereas in maxillary second molars is 3R3C.The symmetry in type of root canals in bilateral maxillary first and second molars were 87.36% and 79.85%, respectively. The similarities of root canal system in adjacent maxillary first and second molars were 53.07% (right side) and 52.58% (left side). The concurrence of MB2 canal in bilateral maxillary first molars is 77.8%, and 35.97% in maxillary second molars. In the 110 patients with MB2 canal in bilateral maxillary second molars, the chance of bilateral MB2 canals in their maxillary first molar is almost 100%. CONCLUSION: Maxillary first molars have higher prevalence of 3R4C than second molars. The symmetry in bilateral maxillary molars is higher than the similarity in adjacent maxillary first and second molars. Application of CBCT analysis of root canal system can improve endodontic treatment outcomes. The correlation of root canal system between teeth is useful for genetic linkage.

Outcome assessment of apical surgery: A study of 234 teeth.

BACKGROUND/PURPOSE: Apical surgery is an option for management of endodontically-treated tooth with persistent periapical lesions or symptom and sign. The objective of this study was to investigate the correlation between the demography, preoperative, postoperative factors and healed rate of apical surgery. METHODS: Subjects were retrospectively collected from patients who received apical surgery/apicoectomy at the Endodontic Department, National Taiwan University Hospital from January 2013 to June 2015. The standard apical surgery procedures were performed. The demography, preoperative clinical and radiographic examination data as well as postoperative variables were collected. The outcome assessment was carried out after surgery. Statistical analysis was performed by chi square test to evaluate the potential outcome predictors. RESULTS: Total 187 patients and 234 teeth receiving apical surgery were included. 53 male and 134 female patients were collected. The age was ranged between 17 and 89 years old and the mean age was 43.64 years old. Better healed rate with significant differences were observed in female patient (p < 0.05), age ≤60 years old (p < 0.01), preoperative root canal filling material >2 mm short of apex (p < 0.01), lesion size from ≤2 mm to ≤12 mm (p < 0.05) and follow-up period â‰§12 months (p < 0.01) groups. CONCLUSION: Gender, age, preoperative root canal filling material extent, lesion size and follow-up period may affect the outcome of apical surgery. Tooth type, post, prosthesis, and lesion area showed no marked effect on apical healing. These results provide more detailed information for the clinical practitioners to make treatment plans and are important for clinical endodontic practices.

Surgical repair of external cervical resorption - Prognosis and prognostic factors.

Background/purpose: External cervical resorption (ECR) is an aggressive form of root resorption, which etiology is unclear and its prognosis remains unpredictable. The purpose of this study was to investigate the prognosis and potential prognostic factors of ECR-affected teeth after surgical intervention for external repair with/without root canal treatment. Materials and methods: Treated ECR cases from 2009 to 2019 were collected retrospectively. The survival of the teeth and the status of root resorption were assessed during the follow-up period. Potential prognostic factors were analyzed with log-rank test and Kaplan-Meier statistics. Results: A total of 42 treated ECR-affected teeth were enrolled. The two-year survival rate was 71.20% [54.16%, 93.59%]. Persistent root resorption was the main complication after treatment. Patients with multiple ECR-affected teeth had greater recurrent potential than patients with solitary ECR-affected teeth. Prolonged calcium hydroxide dressing may contribute to a more favorable clinical outcome. Gender, age, tooth position and the need for root canal treatment did not show statistically significant effect on the prognosis. Conclusion: The current surgical method was able to arrest ECR in most cases. However, the case type (the number of ECR-affected teeth per patient) could highly affect the prognosis of the teeth. Clinicians should consider long-term calcium hydroxide dressing in case of pulp involvement to achieve better results.

An analysis of the relevance and proximity between maxillary posterior root apices to the maxillary sinus and the buccal cortical bone plate.

Background/purpose: Understanding the relationship between maxillary sinus and posterior root apices is critical in preventing dental treatment complications. This study aimed to analyze and showcase the relationship between the posterior root apices and the maxillary sinus floor, the distance to the buccal cortical bone, and their correlation with age, gender, and sides. Materials and methods: Cone-beam computed tomography images were collected from 94 patients with a total of 478 maxillary posterior teeth and 997 roots. The shortest distance from root apices to the closest border of maxillary sinus and the outer buccal cortical bone margin were measured and grouped for statistical analysis for the differences (P < 0.05). Results: The root apices of maxillary molars and single-rooted second premolars were located closer to the maxillary sinus compared to first premolars (P < 0.01). The buccal root of two-rooted first premolar had the shortest horizontal distance to the buccal cortical bone among all roots (P < 0.01). The lowest position of the maxillary sinus floor was mostly located at the palatal side (P < 0.01) and between the buccal and palatal root apices (P < 0.01) in the maxillary premolars and molars, respectively. Increasing age would lead to longer distances between the root apices and the maxillary sinus (P < 0.01). Additionally, male patients had thicker buccal cortical bone than female patients (P < 0.01). Conclusion: Different tooth positions, age, and gender significantly impact the relationships between root apices and the maxillary sinus and buccal cortical plates, informing patient-centered and individually tailored approaches for more effective and safer surgical endodontic treatment.

Invasive Cervical Resorption-Distribution, Potential Predisposing Factors, and Clinical Characteristics.

INTRODUCTION: The purpose of this study was to investigate the distribution, predisposing factors, and clinical characteristics of invasive cervical resorption (ICR). METHODS: Cases with ICR from 2009-2019 were collected. Clinical records and radiographs were reviewed. Descriptive analysis was performed in combination with univariate analysis and the Fisher exact test. RESULTS: A total of 63 ICR teeth from 31 patients (14 men and 17 women) were found. The patients' ages ranged from 18-81 years, with a mean age of 45.77 years. Most patients had a single ICR lesion. Among the 63 ICR teeth, maxillary anterior teeth (47.62%) were the most commonly affected followed by maxillary premolars (20.63%). Maxillary teeth (76.19%) were more prone to ICR than mandibular teeth (23.81%). Most patients denied all major systemic diseases. The most common dental-related factors were dental/orofacial trauma (33.33%), periodontal treatment (26.98%), restoration/crown (17.46%), and orthodontic treatment (15.87%). Most teeth showed no percussion/palpation pain, probing depth >3 mm, abscess formation, sinus tracts, or periapical lesions. The pulp status was mainly vital (73.02%). The presence of percussion pain and probing depth differed significantly among Heithersay ICR classification groups. CONCLUSIONS: ICR showed no difference in sex or age. Maxillary anterior teeth were the most affected in a Taiwanese population. Traumatic injury, periodontal treatment, and orthodontic treatment were the significant predisposing factors. Furthermore, affected teeth typically lacked clinical signs and symptoms. Radiographic examination is critical for early diagnosis. In advanced cases, deep pockets and abscess formation were seen. These results are helpful for the diagnosis of ICR and further effective treatment.

Clinical and Radiographic Characteristics of Vertical Root Fractures in Endodontically and Nonendodontically Treated Teeth.

INTRODUCTION: A vertical root fracture (VRF) is a root fracture extending along the longitudinal axis of roots and is often noted in endodontically treated teeth. However, the clinical and radiographic characteristics of VRFs are not completely known. METHODS: A total of 65 teeth with 68 vertical fractured roots in 58 Chinese patients were investigated. The clinical examination records and radiographic images were reviewed in detail. RESULTS: A total of 24 male (41.38%) and 34 female (58.62%) patients aged 25-90 years (average = 57 years) were included; 51 (87.93%) and 7 (12.07%) patients exhibited 1 tooth and 2 teeth with VRFs, respectively, in the dentition. VRFs occurred mainly in the mesial root (20 roots, 57.14%) of the mandibular molars (29 teeth, 44.62%). Clinically, teeth with VRFs usually presented a periodontal probing depth >5 mm (44 teeth, 91.67%, P < .001) with a prosthesis (55 teeth, 84.62%, P < .001) and a relatively intact dentition (42 patients exhibited <4 missing teeth in the dentition, 77.78%, P < .001). Most of the nonendodontically treated VRFs exhibited attrited occlusal surfaces. Radiographic characteristics of the teeth with VRFs were typically associated with prior root canal treatment (56 teeth, 86.15%, P < .001), periodontal bone loss (62 teeth, 95.38%, P < .001), apical bone loss (52 teeth, 80.00%, P < .001), and periodontal ligament widening (61 teeth, 93.85%, P < .001). The mesial roots of the mandibular molars were most susceptible to VRFs in both endodontically and nonendodontically treated teeth. CONCLUSIONS: These results elucidated some clinical and radiographic and diagnostic features that facilitate VRF identification.

Analysis of the width of vertical root fracture in endodontically treated teeth by 2 micro-computed tomography systems.

INTRODUCTION: Early detection of vertical root fracture (VRF) is important for clinical endodontic practice. The purpose of this study was to measure the fracture width (distance between 2 sides of the fracture) of VRF teeth in vitro by using 2 micro-computed tomography (µ-CT) systems with different spatial resolution and voxel size. METHODS: Thirty-seven endodontically treated teeth with VRF were scanned by 80-µm pixel size µ-CT. Fifteen teeth with no obvious fracture line, blurred image, or fracture space less than 100 µm were scanned by 9-µm pixel size µ-CT. RESULTS: Presence of 2 VRF lines was more common in premolars (82%) than in molars (53%). In 7 premolars (32%) and 9 molars (60%), the VRF lines extended to within the apical 3 mm of the root. All fracture lines were detected by 9-µm pixel size µ-CT, but only 22 of 37 VRF teeth had vertical fracture identified by 80-µm µ-CT. From µ-CT examination, none of the fracture lines showed consistent and uniform fracture space. If 2 fracture lines were present, they were typically in opposite (not linear) directions. There was a significant correlation between 2 fracture lines or fracture lines extending within the 3 mm of the apex and fracture width greater than 100 µm. CONCLUSIONS: Application of 9-µm µ-CT can be accurately used for early detection of VRF. Fracture characteristics (eg, number of fracture lines, extension of fracture line) may affect the fracture width. Appropriate use of µ-CT technology can be helpful for early diagnosis of VRF.

Treatment outcome of the teeth with cemental tears.

INTRODUCTION: A cemental tear is a special type of surface root fracture noted in combination with periodontal and/or periapical bony destruction. We hypothesized that clinical characteristics and treatment techniques may affect the prognosis of teeth with cemental tears. METHODS: Treatment outcome for the teeth with a cemental tear was assessed in a multicenter cemental tear study project. Of the 71 teeth with cemental tears, 38 teeth (53.5%) were extracted. The remaining 33 teeth (46.5%) were examined for a treatment outcome of healed, questionable, or failed. RESULTS: Outcome assessment found that 51.5% (17/33), 42.4% (14/33), and 6.1% (2/33) of teeth were classified as healed, questionable, and failed, respectively. Additive bivariate analysis indicated a significant difference between treatment outcome and the length (P = .01) and apicocoronal location (P = .02) of the separated root fragments. Logistic regression analysis found that treatment technique and apicocoronal location of cemental tears may affect the treatment outcome. The percentage of healed cemental tear cases located in the apical, middle, and cervical third of roots was 11.1%, 66.7%, and 60.0%, respectively. By surgical management, 57.7% of cemental tears were healed, whereas only 28.6% cases were healed after nonsurgical treatment. CONCLUSIONS: Most teeth with cemental tears can be retained to function by nonsurgical and surgical periodontal and endodontic treatment. Clinical diagnosis and treatment of cemental tears should also consider the apicocoronal location and the type of treatment technique to improve outcomes.

Clinical fracture site, morphologic and histopathologic characteristics of cemental tear: role in endodontic lesions.

INTRODUCTION: Clinical research regarding the clinical and histopathologic characteristics of cemental tear is limited in the endodontic literature. The objective of this study was to evaluate the morphology, apicocoronal location, and the histologic characteristics of cemental tear. METHODS: The material was collected during 1987-2009 and consisted of 54 teeth that were presented with cemental tears by histologic examination. To investigate the atypical prospects among the groups of each variable, a series of the Poisson χ(2) goodness-of-fit tests were conducted to test for a fit of a discrete, uniform distribution. RESULTS: Cemental tear occurred mainly in incisors (74.1%), proximal root surfaces (79.6%), male patients (74.1%), and patients older than 60 years (72.3%). They were noted often in the middle third of root (45.3%), but 41.5% of cemental tears were noted over the apical region. The morphology of cemental tear was either small/thin piece-shaped (77.4% cases) involving 1 root surface or U-shaped (22.6%) involving >1 root surface. The size of cemental tear had an average length of 3.8 mm, width of 2.2 mm, and thickness of 0.9 mm. The separations of cemental tears occurred at cementodentinal junction (77.6%) relative to cementum (22.4%). The adhered soft tissue was either granulation tissue (92.3%) or cyst (7.7%). CONCLUSIONS: Cemental tear mainly occurs in incisors of male and older persons. It is also popularly noted in the apical region mimicking an endodontic lesion and some with cystic change. Clinically, endodontists should know this disease entity, make accurate early diagnosis, and totally remove the cemental tear during apical surgery to improve the prognosis.

Cemental tear: clinical characteristics and its predisposing factors.

INTRODUCTION: Cemental tears often show characteristics mimicking a periapical or periodontal lesion. This leads to difficulty in the early diagnosis of cemental tears. METHODS: In this multicenter study, 71 teeth with cemental tears being confirmed by direct inspection or histological examination were included. For each case, demographic data, dental history, clinical and radiographic findings, and the results of exploratory surgery were recorded and analyzed. RESULTS: Maxillary or mandibular incisors (76.1%) were most frequently affected by cemental tears. Univariate analysis of predisposing factors found that teeth with cemental tears occurred more commonly in men (77.5%) and patients older than 60 years of age (73.2%). Analysis of clinical characteristics showed that teeth with cemental tears were prone to have abscess formation (66.2%), a deep pocket >6 mm (73.2%), positive vitality test (65.3%), healthy antagonist teeth (84.3%), and moderate to severe attrition (77.9%). About 56.3% of cemental tears could be detected on preoperative radiographs. Further analysis of radiographic findings showed that teeth with cemental tears were more likely to have periodontal bone destruction (85.9%) or periapical bone destruction (64.8%). CONCLUSIONS: Endodontists and dentists may avoid misdiagnosis and unnecessary treatment of teeth with cemental tears if they can properly evaluate the radiographs and pulp vitality of teeth as well as know the predisposing factors and clinical characteristics of teeth with cemental tears in advance.