Incidence of interappointment emergencies in multiple-visit root canal treatments performed with or without intracanal medicament by undergraduate students.

Objectives: This retrospective cohort study examined the incidence of interappointment emergencies during multiple-visit molar root canal treatments conducted by undergraduate students. Treatments performed without the use of intracanal medicament were compared to treatments that incorporated calcium hydroxide as an intracanal medicament. Materials and Methods: Interappointment emergencies, defined as instances of pain or swelling that required the patient to make an unscheduled follow-up visit, were recorded for up to 2 months after the intervention. To avoid the influence of obturation on the observed incidence of emergency visits, only unscheduled visits occurring between the start and end of the root canal treatment were included. Results: Of the 719 patients included in this study, 77 (10.7%) were recorded as experiencing interappointment emergencies. Of these emergencies, 62% occurred within 2 weeks following the most recent intervention. In the group of patients who did not receive intracanal medicament, the incidence of interappointment emergencies was 11.9% (46 of 385 patients). In comparison, this rate was 9.3% (31 of 334 patients) among those who received calcium hydroxide as an intracanal medicament (odds ratio, 1.33; 95% confidence interval, 0.82-2.15; p = 0.249). Conclusions: Interappointment emergencies may arise at any point during root canal treatment, but they most commonly occur within the first 2 weeks following intervention. The omission of intracanal medicament in multiple-visit molar root canal treatments, performed by undergraduate students, did not significantly increase the incidence of these emergencies.

Influence of Method of Teaching Endodontics on the Self-Efficacy and Self-Perceived Competence of Undergraduate Dental Students.

OBJECTIVE: This study assessed whether self-efficacy and the self-perceived competence of undergraduate dental students had been influenced by the method of teaching endodontics. METHODS: Certain modules of the undergraduate endodontic programme at the Academic Centre for Dentistry Amsterdam (ACTA) including the tutorials, the clinical training and the assessment were revised. The self-efficacy and self-perceived competence close to graduation of an intermediate cohort of 24 students who attended all or some of the former modules or the revised modules were assessed. Additionally, the performance of students in performing root canal treatments was assessed according to predetermined criteria. Data were analysed using Cohen's Kappa, Cronbach's Alpha, Mann-Whitney and T-tests. RESULTS: Self-efficacy and the self-perceived competence of students who followed the former modules of clinical training and assessment were similar to those of students who followed the revised modules. The revised module with higher number of tutorials increased students' self-perceived competence, but did not influence their self-efficacy statistically significantly. Not the entire number, but the number of root canal treatments performed under supervision of endodontists was related with an increase in students' self-efficacy and self-perceived competence. The performance of students in performing root canal tretaments was not statistically significantly related to their self-efficacy and self-perceived competence. CONCLUSION: Among the modules and their components assessed in the present study, only the number of tutorials and the number of root canal treatments performed under supervision of endodontists influenced the self-efficacy and the self-perceived competence of students.

Cone-beam computed tomographic scans in comparison with periapical radiographs for root canal length measurement: an in situ study.

INTRODUCTION: The primary aim of this study was to compare the precision of root canal length determination on cone-beam computed tomographic (CBCT) scans and periapical radiographs (PAs) with the actual root canal length. The secondary aim was to examine the influence of tooth type on root canal length measurements as assessed on CBCT scans and PAs. METHODS: In total, 40 root canals of 33 teeth (molars, premolars, canines, and incisors) out of 5 dentate maxillas of human cadavers were included. Root canal length measurement was performed by a consensus panel (2 examiners) on CBCT scans (3D Accuitomo 170; J Morita, Kyoto, Japan) and digital PAs. After straight-line access opening, a #15 file was fixated in every root canal at the length measured on CBCT scans. All teeth were extracted, and the root canal containing the file was uncovered. Measurements made on images taken with a digital camera (AxioCam; Carl Zeiss, Sliedrecht, The Netherlands) linked to a stereozoom microscope (Stemi SV6, Carl Zeiss) were used as the actual root canal length. RESULTS: When all roots were examined together, it was not clear which method is better for all types of teeth. For root canals of anterior teeth, there was no significant difference between the 2 methods. For root canals of posterior teeth, CBCT images gave results significantly closer to the actual root canal length in comparison with PAs (t value = -1.96; critical value is 1.74 with a significance level of 0.05). CONCLUSIONS: Root canal length measurements of posterior maxillary teeth were more accurate when assessed by CBCT images than PAs.

Volumetric changes in apical radiolucencies of endodontically treated teeth assessed by cone-beam computed tomography 1 year after orthograde retreatment.

INTRODUCTION: Cone-beam computed tomography (CBCT) allows us to assess in 3 dimensions the location and size of periapical radiolucencies. We aimed to assess by CBCT scans the volumetric changes of periapical radiolucencies in endodontically treated teeth 1 year after orthograde retreatment. METHODS: Forty-five root-filled teeth with persistent apical periodontitis requiring endodontic orthograde retreatment from 37 individuals were included in the study. The research protocol was approved by the VU University Medical Center Amsterdam ethics committee (2007/265), and the participants signed a letter of consent. We made 2 CBCT scans for every patient, the first one before retreatment and the second one a year later. Two observers measured independently the volume of radiolucencies on CBCT images by using the AMIRA software. The intraclass correlation coefficient was used to evaluate interobserver agreement, and the Wilcoxon signed rank test was used to assess pretreatment and post-treatment volume size. RESULTS: The intraclass correlation coefficients were 0.994 and 0.998 for the scans before retreatment and 1 year after, respectively. The recall rate was 78% for the teeth and 73% for the patients. The volumetric change in periapical radiolucencies 1 year after retreatment was statistically significant (z = -3.112, P < .005). The volume of periapical radiolucencies reduced in 20 teeth (57%), remained unchanged in 8 (23%), and increased in 7 (20%). CONCLUSIONS: One year after endodontic orthograde retreatment, the volume of periapical radiolucencies reduced significantly in 57% of the teeth.

Detection of vertical root fractures in vivo in endodontically treated teeth by cone-beam computed tomography scans.

INTRODUCTION: The presence of a vertical root fracture (VRF) in an endodontically treated tooth has an immense impact on the treatment's outcome. Early diagnosis of a VRF is imperative to avoid overtreatment and extensive bone loss. Our study aimed to examine the validity of 2 cone-beam computed tomography (CBCT) scanners in detecting VRFs in endodontically treated teeth in vivo. METHODS: Thirty-nine endodontically treated teeth suspected of VRFs from 39 patients were included. No fracture line was visible in periapical radiographs. Two limited-field-of-view scanners were used, the NewTom 3G and the 3D Accuitomo 170. Three observers evaluated the CBCT images independently and twice. The most frequently given score was used to calculate the validity of the CBCT systems. The findings of orthograde retreatment, endodontic microsurgery, or extraction were the gold standard. The intraobserver agreement (Cohen kappa) and the interclass correlation coefficients were calculated. RESULTS: The sensitivity, specificity, and accuracy for the NewTom 3G were 75%, 56%, and 68%, respectively, and for the 3D Accuitomo 170 they were 100%, 80%, and 93%, respectively. The positive predictive value and the negative predictive values were 75% and 55%, respectively, for NewTom 3G and 90% and 100%, respectively, for 3D Accuitomo 170. CONCLUSIONS: The results of our study support the use of 3D Accuitomo 170 for the detection of VRFs in endodontically treated teeth. They also suggest that the reproducibility and accuracy in VRF detection depend on the CBCT system used.

Comparison of five cone beam computed tomography systems for the detection of vertical root fractures.

INTRODUCTION: This study compared the accuracy of cone beam computed tomography (CBCT) scans made by five different systems in detecting vertical root fractures (VRFs). It also assessed the influence of the presence of root canal filling (RCF), CBCT slice orientation selection, and the type of tooth (premolar/molar) on detection accuracy. METHODS: Eighty endodontically prepared teeth were divided into four groups and placed in dry mandibles. The teeth in groups Fr-F and Fr-NF were artificially fractured; those in groups control-F and control-NF were not. Groups Fr-F and control-F were root filled. CBCT scans were made using five different commercial CBCT systems. Two observers evaluated images in axial, coronal, and sagittal reconstruction planes. RESULTS: There was a significant difference in detection accuracy among the five systems (p = 0.00001). The presence of RCF did not influence sensitivity (p = 0.16), but it reduced specificity (p = 0.003). Axial slices were significantly more accurate than sagittal and coronal slices (p = 0.0001) in detecting VRF in all systems. Significantly more VRFs were detected among molars than premolars (p = 0.0001). CONCLUSIONS: RCF presence reduced specificity in all systems (p = 0.003) but did not influence accuracy (p = 0.79) except in one system (p = 0.012). Axial slices were the most accurate in detecting VRFs (p = 0.0001).

Detection of vertical root fractures in endodontically treated teeth by a cone beam computed tomography scan.

Our aim was to compare the accuracy of cone beam computed tomography (CBCT) scans and periapical radiographs (PRs) in detecting vertical root fractures (VRFs) and to assess the influence of root canal filling (RCF) on fracture visibility. Eighty teeth were endodontically prepared and divided into four groups. The teeth in groups A and B were artificially fractured, and teeth in groups C and D were not. Groups A and C were root filled. Four observers evaluated the CBCT scans and PR images. Sensitivity and specificity for VRF detection of CBCT were 79.4% and 92.5% and for PR were 37.1% and 95%, respectively. The specificity of CBCT was reduced (p = 0.032) by the presence of RCF, but its overall accuracy was not influenced (p = 0.654). Both the sensitivity (p = 0.006) and overall accuracy (p = 0.008) of PRs were reduced by the presence of RCF. The results showed an overall higher accuracy for CBCT (0.86) scans than PRs (0.66) for detecting VRF.

Comparison of growth and susceptibility to sodium hypochlorite of mono- and dual-species biofilms of Fusobacterium nucleatum and Peptostreptococcus (micromonas) micros.

This study compared growth and susceptibility to different concentrations of sodium hypochlorite (NaOCl) of mono- and dual-species biofilms of Fusobacterium nucleatum or Peptostreptococcus micros in vitro at 24 hours or 96 hours. A Mann-Whitney U test revealed that although at 24 hours dual-species biofilms had similar viable counts to those of monospecies biofilms (p > 0.001), they were more resistant to NaOCl (p < 0.001). At 96 hours, both microorganisms had higher viable counts and were more resistant to NaOCl in dual-species biofilms than in monospecies biofilms of the same microorganism (p < 0.001). As the age of the biofilms increased, so did their resistance to NaOCl. Mixed-species biofilms of F. nucleatum and P. micros showed a time-dependent synergy in growth and resistance to NaOCl.