Effect of various intracanal materials on the diagnostic accuracy of cone-beam computed tomography in vertical root fractures / 北京大学学报(医学版)

OBJECTIVE@#To study the effect of various intracanal materials on the accuracy of oral maxillofacial cone-beam computed tomography (CBCT) for the diagnosis of vertical root fracture (VRF).@*METHODS@#A total of twenty-four structurally intact single root canal dried and isolated teeth extracted for orthodontic treatment or periodontal disease were collected. The teeth were decrowned along the cemento-enamel junction (CEJ) and then used as samples for the study after conventional root canal preparation and post preparation. The 24 samples were divided into two groups with 12 samples in each group. Group A was the control group (no VRF group). According to intracanal materials, they were divided into five subgroups: blank group, fiber post group, gutta-percha point group, titanium post group and gold-palladium post group. Group B was the experimental group (VRF group), and subgroups were grouped as above. The VRF model was prepared by a unified method in the VRF group: the root was completely fractured in the buccolingual direction with a custom root canal nail and then cemented and reset. The control group was not subjected to the simulation of VRF. Titanium post and gold-palladium post were made according to the individuality of the root canal preparation, and the tightness of the post to the root canal wall was confirmed by X-ray radiograph. Then all the samples were scanned by CBCT in the isolate swine mandibular alveolar sockets. The diagnostic accuracy was statistically analyzed via blind interpretation by experienced endodontic specialists and oral and maxillofacial medical imaging specialists.@*RESULTS@#The accuracy of the diagnosis of VRF in the blank group, fiber post group, gutta-percha point group, titanium post group, and gold-palladium post group in CBCT was 95.83%, 91.67%, 87.50%, 79.17%, and 45.83%, respectively. Compared with the blank group, the differences were not statistically significant in the fiber post group (P>0.999), the gutta-percha point group (P=0.500) and the titanium post group (P=0.125). The lowest diagnostic accuracy of VRF was found in the gold-palladium post group, and the difference was statistically significant compared with all other groups (P < 0.001).@*CONCLUSION@#Various intracanal materials have different degrees of influence on the diagnostic accuracy of VRF diagnosis in CBCT. The influence of fiber post, gutta-percha point and titanium post was small, while the influence of gold-palladium post was significant.

Influence of Vestibular Bevel on the Success of Traumatized Teeth Restorations: Single-Blind Randomized Controlled Trial - Preliminary Results with 6-Months Follow-Up

Abstract Objective: To evaluate the influence of cavosurface vestibular bevel (CSVB) application on the clinical success (CS) of class IV restorations of traumatized permanent teeth, the influence of the number of fracture angles and dental trauma recurrence (DTR) on the restorations retention rate (RRR) and incidence of pulp necrosis (PN). Material and Methods: Fifty-seven children and adolescents with enamel and dentin fractures requiring C-IV restorations were randomly allocated in groups with CSVB and without CSVB. The primary outcomes were the CS of restorations, evaluated using modified USPHS criteria, and the incidence of PN after a 6-months follow-up. As secondary outcomes, the influence of the number of fractured angles and the DTR on the RRR and on the incidence of PN were evaluated (p>0.05). Results: Of 57 children and adolescents, 74 teeth were restored, and 71 completed the six-month follow-up analysis. Teeth restored with and without CSVB displayed similar CS as well as the same incidence of PN (p>0.05). The number of fractured angles did not influence the RRR and DTR was not associated with PN (p>0.05). DTR was associated with a lower RRR (p<0.001). Conclusion: Cavosurface vestibular bevel did not influence the clinical success of Class IV restorations or incidence of PN after 6-months follow-up. DTR did not influence the incidence of pulp necrosis, but did negatively influence the restorations retention rate. The number of fracture angles did not influenced in the restorations retention rate.

Effect of aging on dentinal crack formation after treatment and retreatment procedures: a micro-ct study

Abstract In order to evaluate the volume of dentinal cracks taking into account the age of the dentin and the type of file system used for endodontic procedures, forty freshly extracted single-rooted lower incisive teeth presenting similar root volume, were divided into two groups according to the age of the patient: Group Young (18 - 30 years old) and Group Old (60 years old or more). Each specimen was scanned by microcomputed tomography (micro-CT) in three stages: (i) before any treatment, (ii) after endodontic treatment with Reciproc files (REC), and (iii) after subsequent endodontic retreatment. Each group was subdivided into two subgroups, according to the retreatment technique used: retreatment with REC or with ProTaper Universal Retreatment (PUR) files. For each subgroup, the images were analyzed for differences in the volume of dentinal cracks in the middle and apical thirds of the teeth , according to the dentin age. In both stages (before and after instrumentation), the micro-CT images of the old root dentin presented with higher volume of cracks than those of the young root dentin, statistical significance notwithstanding (p>0.01). The use of REC files appeared to have no statistically significant differences in the generation of cracks in any type of root dentin when compared with PUR files (p>0.01). When retreated with PUR, the old root dentin presented with a significantly higher volume of cracks (p<0.01) when compared with the old root dentin initially.

Resumo Para avaliar o volume de fissuras dentinárias levando em consideração a idade da dentina e o tipo de sistema de limas utilizadas para procedimentos endodônticos, 40 dentes unirradiculares, incisivos inferiores, apresentando similar volume radicular, recentemente extraídos foram divididos em dois grupos de acordo com a idade do paciente: Grupo Jovem (18 a 30 anos) e Grupo Idoso (60 anos ou mais). Cada espécime foi scaneada por microtomografia computadorizada (micro-CT) em três estágios: (i) antes de qualquer tratamento, (ii) após tratamento endodôntico com limas Reciproc (REC) e (iii) após subsequente retratamento endodôntico. Cada grupo foi subdividido em dois subgrupos, de acordo com a técnica de retratamento utilizada: retratamento com REC ou com lima ProTaper Universal Retreatment (PUR). As imagens foram analisadas quanto às diferenças no volume das fissuras dentinárias nos terços médio e apical dos dentes de acordo com a idade da dentina. Em ambos os estágios (antes e depois da instrumentação), as imagens de micro-CT da dentina radicular idosa apresentaram maior volume de trincas do que as jovens, sem significância estatística (p>0.01). O uso das limas REC mostram não ter diferença estatística significante na geração de fissuras, em qualquer tipo de dentina, quando comparadas às limas PUR (p>0.01). Quando retratada com PUR, a dentina radicular idosa apresentou um volume de trincas significativamente maior (p<0.01) quando comparado com a dentina radicular idosa inicialmente.

Pulp canal obliteration after traumatic injuries in permanent teeth - scientific fact or fiction?

Abstract: Pulp canal obliteration (PCO) is a frequent finding associated with pulpal revascularization after luxation injuries of young permanent teeth. The underlying mechanisms of PCO are still unclear, and no experimental scientific evidence is available, except the results of a single histopathological study. The lack of sound knowledge concerning this process gives rise to controversies, including the most suitable denomination. More than a mere semantic question, the denomination is an important issue, because it reflects the nature of this process, and directly impacts the treatment plan decision. The hypothesis that accelerated dentin deposition is related to the loss of neural control over odontoblastic secretory activity is well accepted, but demands further supportive studies. PCO is seen radiographically as a rapid narrowing of pulp canal space, whereas common clinical features are yellow crown discoloration and a lower or non-response to sensibility tests. Late development of pulp necrosis and periapical disease are rare complications after PCO, rendering prophylactic endodontic intervention useless. Indeed, yellowish or gray crown discoloration may pose a challenge to clinicians, and may demand endodontic intervention to help restore aesthetics. This literature review was conducted to discuss currently available information concerning PCO after traumatic dental injuries (TDI), and was gathered according to three topics: I) physiopathology of PCO after TDI; II) frequency and predictors of pulpal healing induced by PCO; and III) clinical findings related to PCO. Review articles, original studies and case reports were included aiming to support clinical decisions during the follow-up of teeth with PCO, and highlight future research strategies.

Effect of Reciprocating Systems and Working Lengths on Apical Microcrack Development: a micro-CT Study

Abstract The objective of this study was to evaluate the effect of root canal preparation with single-file reciprocating systems at different working lengths on the development of apical microcracks using micro-computed tomographic (micro-CT) imaging. Forty extracted human mandibular incisors were randomly assigned to 4 groups (n=10) according to the systems and working length used to prepare the root canals: Group A - WaveOne Gold at apical foramen (AF), Group B - WaveOne Gold 1 mm short of the AF (AF-1 mm), Group C - Unicone (AF) and Group D - Unicone (AF-1 mm). Micro-CT scanning was performed before and after root canal preparation at an isotropic resolution of 14 µm. Then, three examiners assessed the cross-sectional images generated to detect microcracks in the apical portion of the roots. Apical microcracks were visualized in 3, 1, 1, and 3 specimens in groups A, B, C, and D, respectively. All these microcracks observed after root canal preparation already existed prior to instrumentation, and no new apical microcrack was detected. For all groups, the number of slices presenting microcracks after root canal preparation was the same as before canal preparation. Root canal preparation with WaveOne Gold and Unicone, regardless of the working length, was not associated with apical microcrack formation.

Resumo O objetivo deste estudo foi avaliar o efeito da instrumentação de canais radiculares utilizando sistemas reciprocantes de lima única em diferentes comprimentos de trabalho sobre o desenvolvimento de microfissuras apicais utilizando imagens de microtomografia computadorizada (micro-CT). Quarenta incisivos inferiores humanos extraídos foram distribuídos aleatoriamente em 4 grupos (n=10) de acordo com os sistemas e comprimentos de trabalho utilizados para preparar os canais radiculares: Grupo A - WaveOne Gold no forame apical (FA), Grupo B - WaveOne Gold 1 mm aquém do FA (FA-1 mm), Grupo C - Unicone (FA) e grupo D - Unicone (FA-1 mm). Escaneamentos de micro-CT foram realizados antes e após o preparo dos canais a uma resolução isotrópica de 14 μm. Em seguida, três examinadores avaliaram as imagens de secção transversal geradas para detectar microfissuras na porção apical das raízes. Microfissuras apicais foram visualizadas em 3, 1, 1 e 3 espécimes nos grupos A, B, C e D, respectivamente. Todas essas microfissuras observadas após o preparo dos canais radiculares já existiam antes da instrumentação e não foi detectada nenhuma nova microfissura apical. Para todos os grupos, o número de cortes apresentando microfissuras após o preparo dos canais radiculares foi o mesmo verificado antes do preparo dos canais. A instrumentação de canais radiculares utilizando WaveOne Gold e Unicone, independentemente do comprimento de trabalho, não foi associada à formação de microfissuras apicais.

Diagnosis of alveolar and root fractures: an in vitro study comparing CBCT imaging with periapical radiographs

Abstract Objective To compare periapical radiograph (PR) and cone-beam computed tomography (CBCT) in the diagnosis of alveolar and root fractures. Material and Methods Sixty incisor teeth (20 higid and 40 with root fracture) from dogs were inserted in 60 anterior alveolar sockets (40 higid and 20 with alveolar fracture) of 15 macerated canine maxillae. Each fractured socket had a root fractured tooth inserted in it. Afterwards, each maxilla was submitted to PR in two different vertical angulation incidences, and to CBCT imaging with a small field of view (FOV) and high-definition protocol. Images were randomized and posteriorly analyzed by two oral and maxillofacial radiologists two times, with a two-week interval between observations. Results Sensitivity and specificity values were good for root fractures for PR and CBCT. For alveolar fractures, sensitivity ranged from 0.10 to 0.90 for PR and from 0.50 to 0.65 for CBCT. Specificity for alveolar fractures showed lower results than for root fractures for PR and CBCT. Areas under the ROC curve showed good results for both PR and CBCT for root fractures. However, results were fair for both PR and CBCT for alveolar fractures. When submitted to repeated measures ANOVA tests, there was a statistically significant difference between PR and CBCT for root fractures. Root fracture intraobserver agreement ranged from 0.90 to 0.93, and alveolar fracture intraobserver agreement ranged from 0.30 to 0.57. Interobserver agreement results were substantial for root fractures and poor/fair for alveolar fractures (0.11 for PR and 0.30 for CBCT). Conclusion Periapical radiograph with two different vertical angulations may be considered an accurate method to detect root fractures. However, PR showed poorer results than CBCT for the diagnosis of alveolar fractures. When no fractures are diagnosed in PR and the patient describes pain symptoms, the subsequent exam of choice is CBCT.

Effect of Time Lapse on the Diagnostic Accuracy of Cone Beam Computed Tomography for Detection of Vertical Root Fractures

Abstract Accurate and early diagnosis of vertical root fractures (VRFs) is imperative to prevent extensive bone loss and unnecessary endodontic and prosthodontic treatments. The aim of this study was to assess the effect of time lapse on the diagnostic accuracy of cone beam computed tomography (CBCT) for VRFs in endodontically treated dog's teeth. Forty-eight incisors and premolars of three adult male dogs underwent root canal therapy. The teeth were assigned to two groups: VRFs were artificially induced in the first group (n=24) while the teeth in the second group remained intact (n=24). The CBCT scans were obtained by NewTom 3G unit immediately after inducing VRFs and after one, two, three, four, eight, 12 and 16 weeks. Three oral and maxillofacial radiologists blinded to the date of radiographs assessed the presence/absence of VRFs on CBCT scans. The sensitivity, specificity and accuracy values were calculated and data were analyzed using SPSS v.16 software and ANOVA. The total accuracy of detection of VRFs immediately after surgery, one, two, three, four, eight, 12 and 16 weeks was 67.3%, 68.7%, 66.6%, 64.6%, 64.5%, 69.4%, 68.7%, 68% respectively. The effect of time lapse on detection of VRFs was not significant (p>0.05). Overall sensitivity, specificity and accuracy of CBCT for detection of VRFs were 74.3%, 62.2%, 67.2% respectively. Cone beam computed tomography is a valuable tool for detection of VRFs. Time lapse (four months) had no effect on detection of VRFs on CBCT scans.

Resumo Um diagnostico correto e a tempo das fraturas radiculares verticais (FRVs) é essencial para prevenir extensa perda óssea, tratamentos endodônticos e próteses desnecessárias. O objetivo do presente estudo foi avaliar o efeito do tempo decorrido sobre a acurácia diagnóstica da tomografia computadorizada de feixe cônico (TCFC) para detecção de FRVs em dentes de cães tratados endodonticamente. Quarenta e oito dentes incisivos e premolares obtidos de três cães machos adultos tiveram os seus canais tratados. Os dentes foram divididos em dois grupos: no primeiro grupo (n=24) foram artificialmente induzidas FRVs, enquanto no segundo grupo (n=24) os dentes permaneceram intactos. As imagens de TCFC foram obtidas pela unidade NewTom 3G imediatamente após a cirurgia de indução das FRVs e uma, duas, três, quarto, oito, 12 e 16 semanas depois. Três radiologistas cegos para as datas das imagens avaliaram a presença/ausência de FRVs nas imagens de TCFC. Foram calculados os valores da sensibilidade, especificidade e acurácia, sendo os dados analisados por ANOVA e pelo programa SPSS v.16. As acurácias totais de detecção das FRVs imediatamente após sua indução e uma, duas, três, quarto, oito, 12 e 16 semanas depois foram respectivamente de 67,3%, 68,7%, 66,6%, 64,6%, 64,5%, 69,4%, 68,7% e 68%. O efeito do tempo decorrido foi sem significado estatístico (p>0,05). A TCFC produziu valores gerais de sensibilidade, especificidade e acurácia de 74,3%, 62,2% e 67.2%, respectivamente. A tomografia computadorizada de feixe cônico é uma ferramenta valiosa para detecção de FRVs. O tempo decorrido (quatro meses) não teve influência sobre a detecção de FRVs nas imagens de TCFC.

Repair of horizontal root fracture: a case report

Horizontal root fractures in permanent teeth are uncommon injuries among dental traumas. The principle of treating horizontal root fractures of permanent teeth is repositioning and fixation of fractured segment. Diagnosis of tooth fractures based on radiographic findings and the fracture healing process are affected by factors before and after injury. The present case reports the treatment of horizontal root fracture located at the apical-third of upper left and right central incisors. Healing was observed at 1 year follow-up examination

Diagnostic accuracy of conventional, digital and cone beam CT in vertical root fracture detection

Vertical root fracture [VRF] is a common failure in endodontically treated teeth. Due to VRF's poor prognosis, a reliable and valid detection method is critical for treatment planning. Conventional and digital radiographs are limited in VRF detection. Recently, Cone Beam CT [CBCT] system has been introduced. This study aimed to compare the diagnostic accuracy of these three imaging modalities for VRF detection. One hundred and twenty extracted single-rooted teeth were selected and sectioned through cementoenamel junction. The roots were divided in two groups; group one consisted of 60 teeth with induced root fracture and group two had 60 teeth with no fracture. In the first group the crack was made by instron system. All samples were imaged by the three imaging modalities. Diagnostic accuracy was then compared with methylene blue dye detection method. Kappa was used for statistical analysis. CBCT showed the highest sensitivity [94.6%] and specificity [98.2%]. Conventional radiography and digital radiography were not as accurate as CBCT. According to our study, CBCT seems to be better than conventional and digital radiography in detecting VRF and provides the most reliable data in comparison with the two other modalities