Effectiveness of complementary irrigation routines in debriding pulp tissue from root canals instrumented with a single reciprocating file.

AIM: To compare histologically the debridement efficacy of four irrigation techniques in root canals instrumented with a reciprocating single file. METHODOLOGY: From recently extracted premolars with vital pulp, 68 were selected and classified as having round canals (mesiodistal diameter similar to buccolingual) or oval-shaped canals (mesiodistal diameter 2.5 times larger than buccolingual) (n = 32, each) by means of bidirectional radiographs. Four additional uninstrumented samples served as histological controls. The root canals of the specimens were accessed and then instrumented with Reciproc R25® and further assigned to one of four experimental groups according to the complementary irrigation technique: Group I, conventional syringe; Group II, passive ultrasonic irrigation; Group III, manual dynamic activation (MDA); and Group IV, EndoActivator® . Roots were then demineralized and the apical 3 mm was multi-sliced and processed for histologic examination. The percentage of residual pulp tissue was calculated at each cross section. Kruskal-Wallis and Mann-Whitney tests were used to evaluate the effects of irrigation technique, root canal shape and level of cross section on the percentage of residual pulp tissue (P < 0.05). RESULTS: Irrigation technique and root canal shape significantly influenced the percentage of residual pulp tissue (P < 0.05) of canals instrumented with the R25 instrument. Percentage of residual pulp tissue was significantly less using ultrasonic irrigation (P < 0.05), but there was no difference between other irrigation techniques (P > 0.05). Round canals retained significantly less percentage of residual pulp tissue compared to oval-shaped canals (P = 0.001). At 3 mm, there was less pulp tissue compared to levels 2 and 1 mm (P < 0.05). CONCLUSIONS: In canals instrumented with R25 files, ultrasonic irrigation was more effective in removing pulp tissue in the apical level, especially for the debridement of oval-shaped canals.

Postoperative pain after removal of gutta-percha from root canals in endodontic retreatment using rotary or reciprocating instruments: a prospective clinical study.

OBJECTIVES: The aim of this clinical study was to evaluate and compare the incidence and intensity of postoperative pain following removal of gutta-percha from root canals using rotary and reciprocating instruments. MATERIALS AND METHODS: One hundred and sixty patients scheduled for a non-surgical endodontic retreatment were included for evaluation. Preoperative pain was recorded with using a questionnaire with a 10-cm visual analogical scale (VAS). Endodontic filling material was removed with Reciproc (VDW, Munich, Germany) or ProFile (Dentsply Tulsa Dental Specialties, Tulsa, OK) instruments. Patients then recorded their postoperative pain in a VAS pain scale at 4, 8, 16, 24, 48, and 72 h post-treatment. Results were analyzed using the Mann-Whitney U, Kruskal-Wallis, and Chi-square tests. Multivariate logistic and a multiple regression analysis were used to detect the effect of confounding factors. RESULTS: Results showed a direct relation between the intensity of pre-operative pain and that of postoperative pain (P < .05). No significant differences were observed between the two groups regarding postoperative pain (P > .05) as a qualitative variable. As numerical values, statistically significant differences were found regarding sex and the system used (P < .05). CONCLUSIONS: The method for pain evaluation was determinant in postoperative pain findings. Endodontic retreatment preparation with Reciproc results in lower values of postoperative pain compared with ProFile. Women are more susceptible to postoperative pain than are men. CLINICAL RELEVANCE: One of the most significant contributions of this research is the importance given to the method used for pain evaluation. The present study analyzed postoperative pain resulting from the use of reciprocating or continuous rotary instruments during removal of gutta-percha in retreatment procedures.

A new classification system for the restoration of root filled teeth.

The aim of this report is to (i) review the current literature on the status of root filled teeth, (ii) analyse the most important factors in decision-making, (iii) discuss the current restorative concepts, and (iv) classify both the evidence and clinical practice in a way that seeks to be clear, understandable and helpful for clinicians. Restoration of root filled teeth represents a challenge for the clinician and remains a controversial subject. The guidelines describe a new classification that is drawn from evidence presented in the literature and also from clinical expertise-based reviews. It describes five categories of teeth.

Aplicación de la tomografía computarizada de haz cónico en el manejo endodóncico de un molar superior en forma de C / Management of a C-shaped maxillary molar: three-dimensional analysis with cone beam computed tomography

Se presenta un caso de un tratamiento endodóntico de un primer molar superior derecho con una morfología radicular atípica en forma de C. Mediante tomografía computarizada de haz cónico (TCHC) se evidenció la fusión de los conductos palatino y distovestibular en una única raíz. En el artículo se describe la importancia de la correcta identificación de esta variación anatómica mediante los distintos métodos imagenológicos. Se revisa también la literatura respecto a la prevalencia de los molares superiores en forma de C, y el reto que supone en relación a la preparación químico-mecánica y a la obturación tridimensional

This clinical case presents an endodontic treatment of a C-shaped right maxillary first molar which represents an unusual root morphology. The cone beam computed tomography (CBCT) shows a complete fusion of the distobuccal and palatine canals in a single root. The article describes the importance of performing an adequate identification of this complex anatomy using different imaging techniques. It also reviews the literature regarding the prevalence of maxillary molars with a C-shape configuration, the challenge concerning chemical and shaping preparation and also the root canal filling

Supernumerary fourth molar and dental pathologies in a Chalcolithic individual from the El Mirador Cave site (Sierra de Atapuerca, Burgos, Spain).

We present a middle-aged Chalcolithic male with a supernumerary distomolar in the mandible. The prevalence of supernumerary teeth in present-day populations is low, ranging from 0.1% to 3.4%; most supernumerary teeth are documented in the anterior and molar regions of the maxilla in present populations. However, the prevalence of supernumerary molars in past populations is still unknown. Moreover, a complete pathological study has been done of this individual. Maxilla, mandible and teeth have been analyzed searching for dental pathologies. A cone-beam computed tomography (CBCT) analysis of mandibular and maxillary fragments was performed to check the evidence of hyperdontia. Dental wear and maxillary alveolar bone have been analyzed with environmental scanning electron microscope (ESEM) to improve the diagnosis of an abscess and evidence of tooth picking. This individual shows a left distomolar in the mandible without any evidence of other supernumerary teeth. The fourth molar is not associated with any congenital disease. However, this individual suffered severe dental wear and a variety of oral pathologies such as, dental decay, abscesses, pulpitis, periodontal disease, toothpicking marks in an upper molar, arthritis of the temporomandibular joint and malocclusion associated with high masticatory loads. To our knowledge, this individual from El Mirador Cave (Sierra de Atapuerca, Spain) shows the most ancient case of a fourth molar documented. The poor oral health of this individual corresponds to the general dental health of Chalcolithic populations.

Evaluación del estado periapical de dientes tratados endodónticamente mediante radiografías periapicales digitales y tomografía computarizada de haz cónico / Evaluating the periapical status of endodontically treated teeth using digital periapical radiography and cone-beam computed tomography

Objetivos: La radiolucidez apical, signo común de la periodontitis apical, se puede detectar mediante radiografías periapicales (RP) o cortes obtenidos a partir de la tomografía computarizada de haz cónico (TCHC). El objetivo de este estudio clínico fue comparar la prevalencia de lesiones periapicales en raíces individuales de dientes tratados endodónticamente evaluados mediante RP digitales y TCHC. Material y métodos: Se evaluaron un total de 135 dientes (131 pacientes) mediante RP digitales y TCHC. Los dientes fueron clasificados según su diagnóstico en: tejidos apicales normales, periodontitis apical sintomática, periodontitis apical asintomática, absceso apical agudo y absceso apical crónico. Dos examinadores calibrados determinaron la presencia o ausencia de lesión periapical. En caso de desacuerdo, la lectura se discutía hasta alcanzar un consenso. Resultados: Se analizaron 290 raíces emparejadas con RP digitales y TCHC, y se detectaron 159 (54,8%) lesiones periapicales mediante RP digitales. En cambio, se detectaron 204 (70,3%) lesiones periapicales cuando estas mismas 290 raíces fueron observadas mediante TCHC. Además, se observaron 4 raíces accesorias solo identificadas mediante TCHC. Conclusiones: El análisis de las imágenes obtenidas mediante TCHC revelaron un 15,5% más de lesiones periapicales que las obtenidas mediante RP digitales en dientes endodonciados habiendo diferencias estadísticamente significativas (P < .05) en los dientes clasificados como tejidos apicales normales, periodontitis apical sintomática y absceso apical agudo

Objective: Periapical radiolucency, detected on a periapical (PA) radiograph or by reconstructed scans obtained using cone beam computed tomography (CBCT), is a common sign of apical periodontitis. The aim of this study was to compare the prevalence of PA lesions on individual roots viewed with digital PA radiographs and CBCT of endodontically treated teeth. Material and methods: One hundred and thirty-five paired roots (in 131 patients) were evaluated with both radiological systems, digital PA radiographs and CBCT. The teeth were classified according to their diagnosis in cases of normal apical tissues, symptomatic apical periodontitis, asymptomatic apical periodontitis, acute apical abscess and chronic apical abscess. Two calibrated examiners determined the presence of absence of periapical lesion. A consensus agreement was reached if there was any disagreement. Results: Two hundred and ninety paired roots were assessed with PA radiographs and CBCT; periapical lesions were present in 159 (54.8%) roots assessed with digital PA radiographs. When the same 290 sets of roots were assessed with CBCT, lesions were present in 204 (70.3%). Four additional roots were detected with CBCT. Conclusions: The analysis of the images obtained by CBCT revealed 15.5% more PA lesions than those obtained by digital PA radiographs. Statistically significant difference (P <.05) was observed between digital PA radiographs and CBCT for teeth classified as having normal apical tissues, symptomatic apical periodontitis and acute apical abscess

Evaluation of Dentaport ZX and Raypex 6 electronic apex locators: an in vivo study.

INTRODUCTION: Raypex 6 is an electronic apex locator (EAL) that has not yet been tested in vivo. The purpose of this in vivo study was to compare the accuracy of two EALs: the Dentaport ZX and the Raypex 6. METHODS: The study involved 36 straight single-rooted teeth. A 10-K file was advanced until the EAL detected the major foramen. The file was fixed in a replaceable pattern of light-cured composite. The apical part of each canal was trimmed to expose the file tip. The distances from the file tips to the major foramen were measured. RESULTS: Wilcoxon's signed Rank test found no significant differences between the Dentaport ZX and Raypex 6 in terms of their abilities to detect the major foramen (P = .52) The Dentaport ZX was accurate 82.35% of the time to ± 0.5 mm and 97.05% of the time to ± 1 mm, whereas the Raypex 6 was accurate 88.22% of the time to ± 0.5 mm and 100% of the time to ± 1 mm. CONCLUSIONS: No statistically significant differences were observed between the performance of the Dentaport ZX and Raypex 6 EALs under the in vivo clinical conditions used in this study.

An evaluation of the periapical status of teeth with necrotic pulps using periapical radiography and cone-beam computed tomography.

AIM: To evaluate the presence or absence of periapical (PA) radiolucencies on individual roots of teeth with necrotic pulps, as assessed with digital PA radiographs and cone-beam computed tomography (CBCT). METHODOLOGY: Digital PA radiographs and CBCT scans were taken from 161 endodontically untreated teeth (from 155 patients) diagnosed with non-vital pulps (pulp necrosis with normal PA tissue, symptomatic apical periodontitis, asymptomatic apical periodontitis, acute apical abscess and chronic apical abscess). Images were assessed by two calibrated endodontists to analyse the radiographic PA status of the teeth. A consensus was reached in the event of any disagreement. The data were analysed using a McNemar's test, and significance was set at P ≤ 0.05. RESULTS: Three hundred and forty paired images of roots were assessed with both digital PA radiographs and CBCT images. Fifteen additional roots were identified with CBCT. PA radiolucencies were present in 132 (38.8%) roots when assessed with PA radiographs, and in 196 (57.6%) roots when assessed with CBCT. This difference was statistically significant (P < 0.05). In teeth diagnosed with pulp necrosis, symptomatic apical periodontitis or acute apical abscess, CBCT images revealed a statistically larger number of PA radiolucencies than did PA radiographs (P < 0.05). No statistical differences were observed between PA radiographs and CBCT in teeth classified with asymptomatic apical periodontitis (P = 0.31) or chronic apical abscess (P = 1). CONCLUSIONS: Unlike PA radiographs, CBCT revealed a higher prevalence of PA radiolucencies when endodontically untreated teeth with non-vital pulps were examined.

In vivo evaluation of the iPex and Root ZX electronic apex locators using various irrigants.

AIM: To evaluate in vivo the performance of the iPex and Root ZX electronic apex locators (EALs) in the presence of several irrigant solutions: 2.5% sodium hypochlorite (NaOCl) and 2% chlorhexidine (CHX). METHODOLOGY: Thirty-two single-rooted human teeth that were scheduled for extraction were selected. Teeth with metallic restorations, fractures, root resorption, pulp necrosis or open apices were not included The working length (WL) was determined electronically for the root canals with the iPex and Root ZX EALs in the presence of two different irrigant solutions, 2.5% NaOCl and 2% CHX. After the teeth had been extracted, a size 10 K-file was used to determine the reference working length (RWL), which was established at 0.5 mm short of the major foramen. In each case, the RWL was subtracted from the electronic measurements. Positive values indicated electronic measurements that exceeded the RWL (long measurements), whereas negative values indicated measurements that were short of the RWL. The values obtained with the different irrigants and EALs were compared using the paired t-test. Significance was set at P < 0.05. RESULTS: The accuracy of the iPex nor Root ZX EAL was not affected by 2.5% NaOCl or 2% CHX (P > 0.05). However, significant differences were observed between the readings of the iPex and Root ZX, irrespective of whether 2.5% NaOCl or 2% CHX was used as the irrigant (P < 0.05). The iPex was less accurate than the Root ZX in determining the RWL. CONCLUSIONS: The accuracy of neither the iPex nor Root ZX EAL was affected by the irrigant used. However, the iPex was less accurate than the Root ZX in determining the RWL both for 2.5% NaOCl and for 2% CHX.

The effects of six electronic apex locators on pacemaker function: an in vitro study.

AIM: To assess the effects of six electronic apex locators (EALs) on pacemaker function in vitro. METHODOLOGY: Six EALs (Mini Apex Locator®, Dentaport ZX®, Novapex®, Raypex5®, Root ZX mini®, and Justy II®) were tested for electromagnetic interference (EMI) with one pacemaker (Saint Jude Medical). The pacemaker, with a single electrode, was immersed in a saline solution bath adjusted to 400-800 hms to simulate the electrical resistance of the human body and to register the activity by the system. The pacemaker was tested with each of the EALs to analyse the presence of EMI with the EAL switched on, the EAL switched off and during EAL operation. Each series of tests began with a 15-second baseline recording (R0) and continued until all the recording conditions had been covered. The conditions were as follows: R1: recording with the lead of the EAL <2 cm from the tip of the electrode; R2: recording with the lead of the EAL <2 cm from the generator; R3: recording with the lead of the EAL <2 cm from the sensing arc; and R4: recording with the lead of the EAL 15 cm from the sensing arc. If any of the EALs produced interference, its characteristics were categorized. RESULTS: When the lead of the EAL was <2 cm from the tip of the electrode, the majority of the EALs tested produced only background noise. Only one (the Mini Apex Locator) resulted in EMI that was detected as false heart activity. When the EAL was <2 cm from the generator, just one EAL detected background noise (the Mini Apex Locator). When the EAL was <2 cm from the sensing arc or 15 cm from the sensing arc, the recordings were not affected by any of the EALs. There were no significant differences amongst the EALs analysed with respect to the production of EMI. CONCLUSIONS: EMI occurred when the EALs were placed close to the tip of the electrode and occasionally when close to the pacemaker; however, no EMI was detected when the EALs were placed near to or 15 cm from the sensing arc in this laboratory experimental model.

Mandibular first molars with disto-lingual roots: review and clinical management.

The purpose of this review was (i) to conduct a literature review on the prevalence and morphologic classification of mandibular first molars with disto-lingual (DL) roots, and (ii) to discuss the clinical approach to diagnosis and root canal treatment of these teeth. A search was carried out on electronic (MEDLINE, PubMed and Cochrane) and hand databases, which covered all publications from 1970 to December 2011. Two reviewers independently assessed the studies and recorded type of study, origin and sample sizes, number of teeth with three roots and type of root canal configuration. Forty-five studies were identified with a total of 19,056 mandibular first molar teeth. The frequency of DL roots was 14.4% and was associated with certain ethnic populations. The most common canal configuration of mesial and distal roots was Vertucci types IV and I, respectively. No significant differences were observed in the prevalence of DL roots according to gender. Variable results related to side were observed as well as a trend in bilateral occurrence. The root length of the DL roots was in general shorter than that of the disto-buccal roots (DB). Most DL roots had a greater angle of curvature and a smaller radius of curvature in a bucco-lingual orientation. The best methods to identify DL roots are a 25° mesial parallax periapical radiograph or cone-beam computed tomography (CBCT). A trapezoidal shape access cavity is desirable to locate the orifice of the DL canal. Clinicians should be aware of the variable furcation levels during coronal pre-flaring or post-space preparation to avoid furcal/strip perforations and a weakening of DL roots.

Centring ability and apical transportation after overinstrumentation with ProTaper Universal and ProFile Vortex instruments.

AIM: To evaluate morphological changes to the major foramen after overinstrumentation with ProTaper Universal and ProFile Vortex Ni-Ti rotary instruments. METHODOLOGY: Twenty-eight mesiobuccal canals of maxillary and mandibular first molars were divided into two groups of 14 canals each. The root canals were prepared with ProTaper Universal or ProFile Vortex instruments. ProTaper and Vortex instruments were used until the file tip protruded 1 mm beyond the working length (0.5 mm beyond the major foramen). The major foramen was photographed before and after overinstrumentation with each file of the two systems used. The images were superimposed and evaluated using Adobe Photoshop. The parameters evaluated were canal transportation, centring ability and shape of the major foramen. Transportation and centring ability were calculated in two directions: the direction of maximum curvature (MC) and a direction vertical to the maximum curvature (VC). Measurements of canal transportation and centring ability were analysed by anova followed by post hoc least significance difference (LSD) multiple comparisons. RESULTS: No significant differences were observed amongst the different instruments with respect to centring ability in either direction (P > 0.05). The F3 ProTaper Universal instrument was associated with a higher mean values for transportation in the direction of MC (P < 0.05) than the S1, S2 and F1 ProTaper Universal instruments and the size 15, 0.06 taper, size 20, 0.06 taper, and size 25, 0.06 taper ProFile Vortex instruments. The size 30, 0.06 taper ProFile Vortex instrument had a larger mean value for transportation in the direction of MC (P < 0.05) than the S1 ProTaper Universal and size 15, 0.06 taper ProFile Vortex instruments. The S1, S2, F1, F2 and F3 ProTaper Universal files and the size 15, 0.06 taper, size 20, 0.06 taper, size 25, 0.06 taper, and size 30, 0.06 taper ProFile Vortex files produced an oval foramen in 71%, 71%, 85%, 85%, 71%, 71%, 85%, 85% and 89% of the cases, respectively. CONCLUSIONS: In most samples, the ProTaper Universal and ProFile Vortex files produced transportation of the major foramen and created an oval-shaped major foramen after overinstrumentation.

Managing severe curvature of radix entomolaris: three-dimensional analysis with cone beam computed tomography.

AIM: To present a case of a mandibular first molar with an additional distolingual root [radix entomolaris (RE)] and to discuss the use of cone beam computed tomography (CBCT) for its identification and management during root canal treatment. SUMMARY: A 52-year-old Caucasian woman was referred for root canal treatment of the right mandibular first molar (tooth 46). After clinical and radiographic examination, a symptomatic irreversible pulpitis was diagnosed. Three periapical radiographs with different horizontal angulations revealed the presence of an additional distolingual root. This extra root, termed RE, has an incidence of <5% in the Caucasian population. A CBCT examination was also taken, which revealed a severe root canal curvature, especially in the middle third, of this supernumerary root. CBCT provided more accurate information in terms of RE inclination and root canal curvature before commencing root canal treatment. The conventional access opening was modified into a more trapezoidal cavity, and five root canals were found. All canals were instrumented with new nickel-titanium (NiTi) files to reduce the risk of fractured instruments. After preparation, the root canals were filled using thermoplastified techniques. The 1-year follow-up periapical radiographs and CBCT images revealed a continuous periodontal space with no signs of apical periodontitis. KEY LEARNING POINTS: • Cone beam computed tomography imaging is useful in identifying the root canal system and the surrounding structures. • An accurate detection of supernumerary roots, such as RE, can avoid complications during and after root canal treatment. • The analysis of root canal curvature is important because instrument fracture has been linked to angle and radius of curvature. • The use of new instruments can reduce the incidence of instrument fracture.

Efficacy of three different rotary files to remove gutta-percha and Resilon from root canals.

AIM: To evaluate the efficacy of ProTaper Retreatment files, Mtwo Retreatment files and Twisted Files for removal of gutta-percha and Resilon in straight root canals. METHODOLOGY: Ninety single root canals were instrumented and randomly allocated into 6 groups of 15 specimens each with regards to the filling material and instruments used. Group 1: gutta-percha/ProTaper; Group 2: Resilon/ProTaper; Group 3: gutta-percha/Mtwo; Group 4: Resilon/Mtwo; Group 5: gutta-percha/Twisted Files; Group 6: Resilon/Twisted Files. For all roots, the following data were recorded: procedural errors, duration of retreatment, canal wall cleanliness through optical microscope and cone beam computed tomography (CBCT). Data were statistically analysed, and the level of significance was set at P=0.05. RESULTS: No system completely removed the root filling material from root canal walls. No significant differences were observed between the rotary systems in terms of the area of filling material left within the canals (P>0.05). There were statistically significant differences between the filling materials: Resilon/Real Seal had less residual material than gutta-percha/AH plus (CBCT: P=0.01; microscope: P=0.018). Mtwo Retreatment files were more rapid when removing filling material than ProTaper Retreatment files (P=0.19) and Twisted Files (P=0.04). CONCLUSIONS: No system removed the root filling materials entirely. Mtwo Retreatment files required less time to remove root filling material than the other instruments. Resilon was removed significantly better from the canal walls than gutta-percha, irrespective of the rotary instruments used.

Apical transportation created using three different patency instruments.

AIM: To evaluate root canal transportation at the major foramen through the use of stainless steel size 08 K-Flex files, size 10 reamers, and XF finger spreaders when used as patency instruments. METHODOLOGY: One hundred and two mesiobuccal canals of maxillary and mandibular first molars were randomly divided into three groups (34 canals each). Size 08 stainless steel K-Flex files, size 10 stainless steel reamers and stainless steel XF finger spreaders were used as patency instruments in groups A, B and C respectively. The major foramen was photographed before and after instrumentation. The images were superimposed and then evaluated using Photoshop to determine the frequency of apical transportation. The statistic analysis was performed using chi(2)test. RESULTS: Transportation was detected in 22% of the specimens; 9% in group A, 12% in group B and 44% in group C. Significant differences were observed between groups A and C (P = 0.0025) and between groups B and C (P = 0.0069), but not between groups A and B (P = 1.00). CONCLUSIONS: No transportation was found in the majority of the samples when size 08 K-Flex files and size 10 stainless steel reamers were used. The XF finger spreaders, when used to maintain apical patency, caused the greatest transportation of the major foramen.