Evaluation of tooth discoloration after treatment with mineral trioxide aggregate, calcium-enriched mixture, and Biodentine® in the presence and absence of blood.

BACKGROUND: Calcium silicate cements in treatments such as revascularization and apexogenesis are adjacent to blood and pulp tissues. This study evaluated tooth discoloration after treatment with mineral trioxide aggregate (MTA), calcium-enriched mixture (CEM) cement, and Biodentine® in the presence and absence of blood using spectrophotometric analysis. MATERIALS AND METHODS: In this experimental study, A total of 68 extracted permanent anterior teeth were prepared and randomly divided into two groups as follows: the sponge embedded in access cavities was saturated with fresh blood or normal saline using insulin syringe, and then each group was subdivided into the following three cement subgroups: MTA-Angelus®, CEM cement, and Biodentine; these materials with a thickness of 3 mm were placed in the access cavity on the sponge. In the control group, the sponges were saturated in saline and blood in the absence of cements. Discoloration rate was measured by spectrophotometer within the following four intervals: after preparing the cavity and 1 day, 1 month, and 6 months after material placement. ANOVA and Tukey's test were used to assess the effect of blood and materials and time on discoloration. (P < 0.05). RESULTS: In general, discoloration rate is significantly higher in blood group than saline group (P < 0.05) and an increase in Δ E is observed over time for the materials in all groups. In this study, discoloration rate in the presence and absence of blood in Biodentine group was lower, and this difference was statistically significant compared to that of MTA group (P < 0.05) but not significant compared to that of the CEM group. CONCLUSION: This study indicated that Biodentine induces the lowest tooth discoloration in the presence and absence of blood, and its discoloration rate is significantly lower than that of MTA. Therefore, it can be suggested that Biodentine can be used more confidently for endodontic treatments with coronal blood contamination such as regeneration and cervical perforation repair in esthetic zone of teeth.

Diagnostic Accuracy of High Resolution Cone-beam Computed Tomography and Standard Mode Cone-beam Computed Tomography in Internal Root Resorption.

Introduction: The purpose of this study was to compare the high resolution cone-beam computed tomography (CBCT) and standard mode CBCT diagnostic accuracy in internal root resorption with different sites and sizes. Methods and Materials: Eighty single rooted human teeth with visible pulps in periapical radiography were split mesiodistally along the coronal plane. Internal resorption like lesions were created in three areas (cervical, middle and apical) in labial wall of the canals in different diameters. High resolution CBCT (CBCT-H) and standard mode CBCT (CBCT-C) were taken from each tooth. Two observers examined the high resolution CBCT and standard mode CBCT to evaluate the presence of resorption cavities. The data were statistically analyzed and degree of agreement was calculated using Cohen's kappa (k) values. Data were analyzed by SPSS 20 software and sensitivity, specificity and positive and negative predictive value for both methods were calculated. Data were analyzed using the Mac-Nemar and chi-square tests. Result: The positive predictive value and negative predictive value in CBCT-H was higher than that of CBCT-C, all of which indicates that the CBCT-H diagnostic test is more sensitive and more accurate than CBCT-C. Kappa statistics showed that there is a strong and complete agreement between the CBCT high resolution and reality (kappa: 0.72) and in the Standard CBCT method, a moderate agreement has been obtained with reality (Kappa: 0.45). Conclusion: According to our in vitro study CBCT high resolution has a higher diagnostic accuracy than conventional CBCT.

Evaluation of the Prevalence of Complete Isthmii in Permanent Teeth Using Cone-Beam Computed Tomography.

INTRODUCTION: The current study aimed at determining the prevalence of complete isthmii in permanent teeth, using cone-beam computed tomography (CBCT) in a selected Iranian community. METHODS AND MATERIALS: In this cross sectional study, 100 CBCT images (from 58 female and 42 male patients) including 1654 teeth (809 maxillary and 845 mandibular teeth) were evaluated. Each tooth root was evaluated in axial plane (interval, 0.1 mm; thickness, 0.1 mm) from the orifice to the apex and from the apex to the orifice to detect the presence of complete isthmus. Scans of teeth with complete isthmii were reevaluated in axial, sagittal, and coronal planes with the thickness, 0.1 mm. Presence and absence of complete isthmii in each tooth was reported. The root canal was divided into 3 equal parts (cervical, middle and apical thirds), and isthmii were classified with respect to the start and end points. Findings were classified into 6 categories with respect to the start and end points of the isthmii: 1) the beginning and end in the cervical third; 2) the beginning in the cervical third and end in the middle third ; 3) the beginning in the cervical third and end in the apical third ; 4) the beginning and end in the middle third ; 5) the beginning in the middle third and end in the apical third and 5) the beginning and end in the apical third. RESULTS: The prevalence of complete isthmus in permanent teeth was 8.6%, and the highest prevalence was reported in mesial roots of the mandibular first molars. In maxilla, the highest prevalence of complete isthmus was found in mesiobuccal roots of the maxillary first molars, whereas in canines and central incisors, no isthmii were detected. In the mandible, the lowest prevalence of isthmus was found in second premolars. In maxillary molars, isthmii starting and ending in the middle third of the root had the highest prevalence. On the other hand, isthmii in mandibular molars, from apical or middle third of the root beginning to the end of the apical third, had the highest prevalence. CONCLUSION: As the prevalence of complete isthmii was the highest in molars, endodontists should pay particular attention to accomplish a successful surgical or nonsurgical root canal therapy.

Transportation and Centering Ability of Neoniti and ProTaper Instruments; A CBCT Assessment.

INTRODUCTION: Transportation is an important iatrogenic endodontic error which might cause failure. This study evaluated the canal transportation caused by Neoniti and ProTaper instruments, using cone-beam computed tomography (CBCT) cross sections. METHODS AND MATERIALS: This in vitro experimental study was performed on 40 mesiobuccal roots of maxillary first molars. The teeth were scanned with CBCT. They were randomly divided into 2 groups (n=20) that were prepared using either Neoniti or ProTaper files. An endodontist prepared the canal according to the manufacturer's guidelines. Prepared canals were re-scanned. The pre-instrumentation and post-instrumentation CBCT volumes were sectioned at 1 to 9-mm distances from the apex. The extent of canal dentine removal in mesial and distal directions were measured in each cross-section. Canal transportation and instrument centering ability were estimated based on the extents of root wall removal and were compared in both groups. RESULTS: The groups were rather similar in terms of transportation and centering ability (P>0.05). However, canal preparation on mesial and distal walls was statistically significantly less in the Neoniti group, at most cross-sections. Transportation of both groups was not significantly different (P>0.05). Centering ability of both instruments was not significantly different (P>0.05). CONCLUSION: Neoniti and ProTaper instruments might have proper centering ability and minimum transportations. Both instruments might cause similar extents of transportation and centering abilities.

Diagnostic Accuracy of Cone-Beam Computed Tomography and Periapical Radiography in Internal Root Resorption.

INTRODUCTION: The aim of this study was to compare the diagnostic value of cone-beam computed tomography (CBCT) and periapical (PA) radiography in detecting internal root resorption. METHODS AND MATERIALS: Eighty single rooted human teeth with visible pulps in PA radiography were split mesiodistally along the coronal plane. Internal resorption like lesions were created in three areas (cervical, middle and apical) in labial wall of the canals in different diameters. PA radiography and CBCT images were taken from each tooth. Two observers examined the radiographs and CBCT images to evaluate the presence of resorption cavities. The data were statistically analyzed and degree of agreement was calculated using Cohen's kappa (k) values. RESULTS: The mean±SD of agreement coefficient of kappa between the two observers of the CBCT images was calculated to be 0.681±0.047. The coefficients for the direct, mesial and distal PA radiography were 0.405±0.059, 0.421±0.060 and 0.432±0.056, respectively (P=0.001). The differences in the diagnostic accuracy of resorption of different sizes were statistically significant (P<0.05); however, the PA radiography and CBCT, had no statistically significant differences in detection of internal resorption lesions in the cervical, middle and apical regions. CONCLUSION: Though, CBCT has a higher sensitivity, specificity, positive predictive value and negative predictive value in comparison with conventional radiography, this difference was not significant.

The effect of metal artifacts on the identification of vertical root fractures using different fields of view in cone-beam computed tomography.

PURPOSE: The aim of this study was to investigate the effects of metal artifacts on the accurate diagnosis of root fractures using cone-beam computed tomography (CBCT) images with large and small/limited fields of view (FOVs). MATERIALS AND METHODS: Forty extracted molar and premolar teeth were collected. Access canals were made in all teeth using a rotary system. In half of the teeth, fractures were created by the application of mild pressure with a hammer. The teeth were then randomly put into a wax rim on an acryl base designed in the shape of a mandible. CBCT scans were obtained using a Newtom 5G system with FOVs of 18 cm×16 cm and 6 cm×6 cm. A metal pin was then placed into each tooth, and CBCT imaging was again performed using the same fields of view. All scans were evaluated by two oral and maxillofacial radiologists. The specificity, sensitivity, positive predictive value, negative predictive value, and likelihood ratios (positive and negative) were calculated. RESULTS: The maximum levels of sensitivity and specificity (100% and 100%, respectively) were observed in smallvolume CBCT scans of teeth without pins. The highest negative predictive value was found in the small-volume group without pins, whereas the positive predictive value was 100% in all groups except the large-volume group with pins. CONCLUSION: The specificity of CBCT decreased with the presence of a pin in the large-volume group, but not in the small-volume group.

Assessment of vertical root fracture using cone-beam computed tomography.

PURPOSE: The aim of this study was to investigate the accuracy of cone-beam computed tomography (CBCT) in the diagnosis of vertical root fractures in a tooth with gutta-percha and prefabricated posts. MATERIALS AND METHODS: This study selected 96 extracted molar and premolar teeth of the mandible. These teeth were divided into six groups as follows: Groups A, B, and C consisted of teeth with vertical root fractures, and groups D, E, and F had teeth without vertical root fractures; groups A and D had teeth with gutta-percha and prefabricated posts; groups B and E had teeth with gutta-percha but without prefabricated posts, and groups C and F had teeth without gutta-percha or prefabricated posts. Then, the CBCT scans were obtained and examined by three oral and maxillofacial radiologists in order to determine the presence of vertical root fractures. The data were analyzed using IBM SPSS 20.0 (IBM Corp., Armonk, NY, USA). RESULTS: The kappa coefficient was 0.875±0.049. Groups A and D showed a sensitivity of 81% and a specificity of 100%; groups E and B, a sensitivity of 94% and a specificity of 100%; and groups C and F, a sensitivity of 88% and a specificity of 100%. CONCLUSION: The CBCT scans revealed a high accuracy in the diagnosis of vertical root fractures; the accuracy did not decrease in the presence of gutta-percha. The presence of prefabricated posts also had little effect on the accuracy of the system, which was, of course, not statistically significant.

Analgesic effect of etoricoxib compared to ibuprofen on post endodontic pain.

AIMS: Etoricoxib is a second-generation selective COX-2 inhibitor. There are a few researches investigating analgesic effect of Etoricoxib in dentistry. METHODS: This randomized, double-blind, active-control study included sixty patients with clinical pulpal diagnosis of necrosis of the first mandibular molar and an associated periapical radiolucency who experienced severe pain (more than 60 out of 100 in scale of Visual Analog Scale (VAS). The patients were equally randomized into four groups, who received 60 mg etoricoxib (group 1), 90 mg etoricoxib (group 2), 120 mg etoricoxib (group 3), and 400 mg ibuprofen (group 4). All patients randomly received a single dose of the drug after the first session of the root canal therapy. Using VAS, the severity of pain was recorded 2, 4, 6, 12, 24, 48, and 72 hours after the drug was administered. RESULTS: Changing trends of pain over the time was significant for all groups (P=0.003). In addition, there was not a significant difference between various study arms (P=0.146). CONCLUSION: The results showed that ibuprofen had a comparable effect with various dosage of etoricoxib and may remain as the choice analgesic for dental pulpal pain.