Debris and Smear Layer Removal in Curved Root Canals: A Comparative Study of Ultrasonic and Sonic Irrigant Activation Techniques.

The aim of this study was to compare the cleaning efficacy of three irrigant activation devices with a control of non-activated syringe and needle irrigation in curved root canals. Sixty human curved roots were endodontically prepared and divided into four groups (n = 15) with similar root curvature distributions. Final irrigation using 4% NaOCl was performed with a syringe and needle (30-G) alone, or with Eddy sonic powered irrigation system (polymeric tip #0.25/0.06), Endosonic ultrasonic activation (polymeric tip #0.25/0.03), or Irrisafe ultrasonic activation (stainless-steel tip, #0.25/0.00). SEM was used to evaluate cleaning efficacy, employing five-score systems for debris and smear layer. While no significant difference in debris removal was observed between Endosonic or Irrisafe activation and non-activated irrigation, Eddy sonic powered irrigation system significantly improved debris removal in the apical third of curved root canals. Smear layer removal was effective in coronal and mid-root sections for all groups but less so in the apical third. Thus, Eddy sonic powered irrigation system demonstrated higher efficacy in removing debris from the apical third of curved root canals compared with non-activated syringe and needle irrigation. However, all three irrigant activation systems exhibited no difference from the non-activated control in smear layer removal.

Efficacy of Different Irrigant Activation Systems on Debris and Smear Layer Removal: A Scanning Electron Microscopy Evaluation.

Background: Irrigation is an essential component of root canal treatment to enable cleaning beyond the reach of mechanical instruments. The study aimed to assess and compare the efficacy of different final irrigation protocols, including sonic- and ultrasonic-powered irrigant-activation systems, on debris and smear layer removal in the coronal, middle, and apical thirds of straight oval root canals. Materials and Methods: Straight oval root canals of 60 human mandibular incisors were prepared to size 40.04 and divided into four groups (n = 15) according to the final irrigation protocols: (a) Eddy sonic activation (b) endosonic passive ultrasonic irrigation (PUI), (c) irrisafe PUI, and (d) manual syringe and needle irrigation with no additional activation, which served as control. After the treatment procedures, the roots were split and observed using scanning electron microscopy. The presence of remaining debris and smear layer at the coronal, mid-root, and apical thirds of the canals were evaluated using a score system and statistically analyzed using multinominal models with significance level set at p < 0.05. Results: None of the final irrigation protocols completely removed all debris and smear layer from all root canals. When the syringe and needle were used without activation, more debris and smear layer were found in the apical third of the canals. Activation of the final irrigant with each of the three devices significantly reduced the presence of debris in the apical third, compared to the syringe and needle final irrigation, with no difference among the three activation devices. Eddy and irrisafe activation also significantly reduced the residual smear layer in the apical third, compared to syringe and needle alone, while the reduction in the remaining smear layer by endosonic activation did not reach the significance level. Conclusions: Removal of debris and smear layer from the apical part of the root canal by syringe and needle irrigation alone may be significantly improved by using sonic or ultrasonic activation of the final irrigant. Endosonic activation was less effective in removal of smear layer from the apical part of the canals compared to the other two activation systems.

Micro-CT Study of the In Vivo Accuracy of a Wireless Electronic Apex Locator.

INTRODUCTION: This study aimed to compare the in vivo accuracy of Wirele-X and RootZX II electronic apex locators (EALs) in determining the position of the major foramen using micro-computed tomography (micro-CT) as the analytical tool. METHODS: Eleven vital teeth planned for extraction from 5 patients were used. After conventional access cavity preparation, root canals were flared and negotiated up to the apical third with sizes 08 and 10 K-files followed by irrigation with 2.5% NaOCl. K-type files were used to determine the working length of the selected canals using Root ZX II and Wirele-X apex locators until their numeric displays read "0.0." After fixing the silicon stop to the file, teeth were extracted and imaged in a micro-CT device using a double-scan protocol. Image stacks, with and without the file in the root canal, were then co-registered and the measurement error calculated as the absolute difference between the tip of the file and the major foramen. Positive and negative values were recorded when the file tip was detected beyond or short of the major foramen, respectively. Accuracy was determined on stable measurements within ± 0.5 mm when the file tip did not extend beyond the major foramen. The χ2 test was applied to compare the ability of the EALs to detect the position of the major foramen, and the t test for dependent variables was used to verify differences in the 2 measurements obtained in each tooth. Significance level was set at 5%. RESULTS: Within a tolerance level of ± 0.5 mm, no significant differences were observed between the tested EALs regarding the absolute distance values (P = .82) or in their ability to detect the position of the major foramen (χ2 = 0.2588; P = .6109). The accuracy of the Root ZX II and the Wirele-X apex locators within ± 0.5 mm were 81.8% and 90.9%, respectively. CONCLUSIONS: Root ZX II and Wirele-X performed similarly regarding the in vivo detection of the major foramen. Using strict criteria, the accuracy of the Root ZX II and the Wirele-X apex locators were 81.8% and 90.9%, respectively.

Healing after surgical retreatment at four time points: A retrospective study.

AIM: To evaluate the outcome of surgical retreatment at four time points, that is 6, 12, 24 and 48 months post-operatively, and to search for prognostic factors that may affect the outcome. METHODOLOGY: Clinical records and intraoral periapical radiographs were collected from patients who had undergone surgical retreatment between 2009 and 2015 and attended 6-, 12-, 24- and 48-month follow-up visits. Surgical retreatment was performed by one endodontist and involved minimal root-end resection and maximal length root-end preparation using prebent ultrasonic files. Outcomes were categorized as complete, incomplete, uncertain or unsatisfactory healing, based on clinical and radiographic findings. The complete and incomplete categories were pooled and considered successes, while uncertain and unsatisfactory outcomes were considered failures. Changes in healing outcome were analysed using the McNemar-Bowker test, and prognostic factors were analysed using univariate analysis. RESULTS: The study cohort included 297 patients with 384 teeth. The overall success rate after 48 months was 90.6% compared with 88.5%, 93% and 92.4% after 6, 12 and 24 months respectively. Age, gender, presence of isthmus and length of canal preparation had no significant influence on the outcome. Lesion size and tooth type had a significant influence only after 6 and 12 months, respectively, with no significant differences at other time points. Fifty per cent of the teeth classified as unsatisfactory or uncertain healing at the 6 months follow-up improved to incomplete or complete healing after 12 months. None of the cases classified as unsatisfactory healing after 12 months subsequently improved, and only 2 cases that were classified as uncertain healing after 12 months improved after 24 months. CONCLUSIONS: Surgical retreatment was found to be a predictable procedure with a high success rate of 90.6% after 4 years. Over the follow-up periods, only a minor regression in the success rate was found. The 12 months follow-up results closely indicated the long-term outcome of surgical retreatment.

Apical extrusion of debris during the preparation of oval root canals: a comparative study between a full-sequence SAF system and a rotary file system supplemented by XP-endo finisher file.

OBJECTIVES: The purpose of this study was to assess the amount of apically extruded debris during the preparation of oval canals with either a rotary file system supplemented by the XP-endo Finisher file or a full-sequence self-adjusting file (SAF) system. MATERIALS AND METHODS: Sixty mandibular incisors were randomly assigned to two groups: group A: stage 1-glide path preparation with Pre-SAF instruments. Stage 2-cleaning and shaping with SAF. Group B: stage 1-glide path preparation with ProGlider file. Stage 2-cleaning and shaping with ProTaper Next system. Stage 3-Final cleaning with XP-endo Finisher file. The debris extruded during each of the stages was collected, and the debris weights were compared between the groups and between the stages within the groups using t tests with a significance level set at P < 0.05. RESULTS: The complete procedure for group B resulted in significantly more extruded debris compared to group A. There was no significant difference between the stages in group A, while there was a significant difference between stage 2 and stages 1 and 3 in group B, but no significant difference between stages 1 and 3. CONCLUSIONS: Both instrumentation protocols resulted in extruded debris. Rotary file followed by XP-endo Finisher file extruded significantly more debris than a full-sequence SAF system. Each stage, in either procedure, had its own contribution to the extrusion of debris. CLINICAL RELEVANCE: Final preparation with XP-endo Finisher file contributes to the total amount of extruded debris, but the clinical relevance of the relative difference in the amount of apically extruded debris remains unclear.

Efficacy of self-adjusting file, XP-endo finisher and passive ultrasonic irrigation on the removal of calcium hydroxide paste from an artificial standardized groove.

The purpose of this study was to compare the effectiveness of self-adjusting file (SAF), XP-endo finisher (XP), passive ultrasonic irrigation (PUI) and conventional syringe and needle irrigation (SNI) in the removal of Ca(OH)2 from an artificial groove. Eighty mandibular incisors with single oval canals were prepared to size 40/0.04 and split longitudinally. A standardised groove was prepared in the apical third and filled with Ca(OH)2 . The root halves were reassembled and divided into two control groups (n = 4) and four experimental groups (n = 18) according to the removal methods used. The amount of residual Ca(OH)2 was evaluated using a four-grade scoring system. The differences among the groups were analysed using the Kruskal-Wallis test (P < 0.05). SAF, XP and PUI removed significantly more Ca(OH)2 than SNI (P < 0.001), although there were no significant differences among them (P = 0.209). None of the tested methods could completely clean Ca(OH)2 from the groove.

Anaesthetic efficacy of intraligamentary injection techniques on mandibular molars diagnosed with asymptomatic irreversible pulpitis: A retrospective study.

The objective of this study was to evaluate the success rate of intraligamentary injections (ILI) using a two- or four-site injection technique. One hundred and fifty-one mandibular molars diagnosed with asymptomatic irreversible pulpitis received ILI at the mesiobuccal and distobuccal aspects of the roots. Patients who experienced pain when the access cavity was performed received additional supplemental ILI in the mesiolingual and distolingual aspects. Pulpal anaesthesia was considered successful when complete analgesia was achieved. The data were analysed by means of the Fisher's exact and Pearson's chi-square tests. IL anaesthesia was successful for 92.1% of the teeth. Forty-eight teeth (31.8%) were sufficiently anaesthetised using the two-site ILI and 91 teeth (60.3%) following supplemental IL anaesthesia in two more sites. The results of this study indicate that the use of four-site IL injections as a primary anaesthetic technique may be considered a favourable alternative to the common IANB.

Occurrence and timing of complications following traumatic dental injuries: A retrospective study in a dental trauma department.

BACKGROUND: This study explores the pattern of complications occurrence resulting from traumatic dental injuries, the relation of this pattern to the number of years from the time of the injury to its first diagnosis, and other contributing characteristics such as root development and trauma characteristic. MATERIAL AND METHODS: Patients' data treated following dental trauma from 2002 to 2014 were classified and grouped according to age, gender, tooth type, injury type, diagnosis and the time that elapsed between the traumatic event and the diagnosis of complications (TIC). The distribution function of the quantitative parameters was determined with the Kolmogorov-Smirnov test. Fisher exact test was used to test differences between categorical parameters. RESULTS: The review identified 166 patients (114 male and 52 female), with a total of 287 traumatized teeth, and a mean of 1.8 injured teeth per incident. Maxillary teeth were involved significantly more often in traumatic dental injuries. The follow-up period range (TIC) had a mean of 2.99 years. The most frequent complication was pulp necrosis (34.2%). The most frequent complication related to avulsion was ankylotic root resorption (50%) diagnosed after a median TIC of 1.18 years. Open apices at the occurrence of trauma were observed in 52 teeth. Of these, 54.9% experienced pulp necrosis and 9.8% inflammatory root resorption with a median TIC of 1.63 years. Teeth that experienced multiple traumatic events showed significantly more late pulp necrosis compared to teeth that experienced a single traumatic injury (61.9% vs. 25.3%, respectively, p<0.0001). CONCLUSIONS: Follow-up periods should be based on the type of traumatic dental injury and the severity of the potential complications for the tooth. Current recommendations for follow-up after traumatic dental injury should be revised to reflect the need for more frequent and overall prolonged follow-up. Key words:Dental trauma, avulsion, open apex, pulp necrosis, root resorption, follow-up, complications.

An ex vivo comparison of working length determination by three electronic root canal length measurement devices integrated into endodontic rotary motors.

AIM: The objective of this study was to compare the accuracy of working length (WL) determination by X-Smart Dual, ENDOAce, and Gold Reciproc motor, in manual mode and mechanical preparation set to auto apical reverse (AAR) mode. MATERIALS AND METHODS: Forty-five anterior teeth were included in the study. The canal length was determined by introducing #10 file into the canal until it emerged at the apical foramen. The incisal edges were adjusted to obtain 18 mm standard length. The teeth were embedded in Plexiglas tubes, filled with alginate, and measured in manual and AAR modes. RESULTS: Within and between the groups, there was no significant difference in WL measurements, both in manual and AAR modes. In the X-Smart Dual group, all manual measurements were within root canal limits, while 13 % of AAR mode measurements were recorded when the file tip passed the apical foramen. In the ENDOAce group, 13 and 7 % of the measurements, in manual and AAR modes respectively, were recorded when the file tip passed the foramen. In the Gold Reciproc motor group, 27 and 33 % of the measurements, in manual and AAR modes respectively, were recorded when the file tip passed the foramen. CONCLUSION: With the limitation of this ex vivo study, the tested devices presented no significant differences in length measurements and were within the clinical accepted margin of error. CLINICAL RELEVANCE: Mechanical preparation must be confined to the root canal system. The adverse results of overinstrumentation emphasize the need to reconsider the ±0.50 mm margin of error that is clinically acceptable for WL measurements.

Evaluation of Root Canal Cleaning and Shaping Efficacy of Three Engine-driven Instruments: SafeSider, ProTaper Universal and Lightspeed LSX.

AIM: To compare the cleaning effectiveness and shaping ability of SafeSider, ProTaper Universal and Lightspeed rotary instruments during the preparation of curved root canals in extracted human teeth. MATERIALS AND METHODS: A total of 63 roots with curved root canals were divided into three groups. Canals were prepared using SafeSider, ProTaper Universal or Lightspeed LSX. Using pre- and post-instrumentation radiographs, straightening of the canal curvatures and loss of working length were determined with a computer image analysis program. The amounts of debris at the apical 5 mm were quantified on the basis of a numerical evaluation scale. The data were analyzed statistically using the two-way analysis of variance (ANOVA). RESULTS: There was significantly more transportation among the Lightspeed LSX group compared to the SafeSider and ProTaper Universal groups only at the 4 mm level (p < 0.05). The ProTaper Universal instruments performed significantly faster than other groups. No significant differences were observed between the three engine-driven instruments with regards to debris removal. CONCLUSION: SafeSider, ProTaper Universal and Lightspeed LSX rotary instruments maintained the original canal curvature well at the apical 3 mm and were safe to use. No difference was found in cleaning efficacy and none rendered the apical part of the canal free of debris. CLINICAL SIGNIFICANCE: SafeSider, ProTaper Universal and Lightspeed LSX rotary instruments are safe to use in curved root canals.

Fusion of central incisors with supernumerary teeth: a 10-year follow-up of multidisciplinary treatment.

INTRODUCTION: Macrodontia of anterior teeth may occur as an isolated condition or as a result of fusion or gemination and may cause clinical problems such as tooth crowding and esthetic problems. Preliminary planning and careful management are often required by a dental team comprising an orthodontist, an endodontist, a prosthodontist, and an oral surgeon. A multidisciplinary treatment approach in a case with fused teeth is presented. METHODS: A 9-year-old girl presented with macrodontia of a left maxillary central incisor. The patient was referred to the orthodontic department because of a large central incisor as a result of fusion with an unspecific supernumerary tooth. The surgical procedure included sectioning off the mesial segment as far as possible, both apically and subgingivally, and extracting 1 of the fused supernumerary teeth. During the sectioning procedure, the pulp of the remaining tooth was exposed at the middle third of the root. Direct pulp capping was performed by an endodontist using mineral trioxide aggregate. Twelve weeks later, orthodontic treatment was commenced, and finally after a 26-month orthodontic treatment period, the central incisors' crown was restored using composite material. RESULTS: A 10-year clinical and radiographic follow-up revealed that the remaining resected central incisor kept its vitality, and the patient was pleased with the esthetic result. CONCLUSIONS: Proper interdisciplinary treatment planning of complicated cases such as anomalous teeth, which involve fusion to a supernumerary tooth, may lead to minimal invasive conservative procedures that maintain tooth vitality and result in a pleasing esthetic result.

Accuracy and reliability of working length determination by Gold Reciproc Motor in reciprocating movement.

INTRODUCTION: The purpose of this study was to assess the accuracy and reliability of the apex locator function of the Gold Reciproc Motor (VDW GmbH, Munich, Germany) during reciprocating movement. METHODS: Forty extracted incisors with mature apices were included in the study. The canal length was determined by introducing #10 file into the canal until it emerged at the apical foramen. The incisal edge of each tooth was adjusted to obtain 18 mm standard length and to produce a flat reference point. The teeth were embedded in Plexiglas tubes filled with alginate and measured by Root ZX (J. Morita Corp, Tokyo, Japan) and Bingo 1020 (Forum Engineering Technologies, Rishon Lezion, Israel) apex locators. The root canals were instrumented in a reciprocating mode using an R25 Reciproc file in the Gold Reciproc Motor until the green LEDs and orange LED were reached. According to the manufacturer, these LEDs represent the zone between the apical constriction and the apical foramen. RESULTS: No statistically significant differences were found between the length measurements of the 2 electronic apex locators and the third green LED, which is suggested by the manufacturers as the recommended working length. CONCLUSIONS: With the limitation of this ex vivo study, the Gold Reciproc Motor's integrated electronic apex locator was found to be as reliable and accurate as the Root ZX and Bingo 1020 apex locators in terms of length control during root canal preparation in the reciprocation mode.

Oral cutaneous sinus tract, vertical root fracture, and bisphosphonate-related osteonecrosis: a case report.

INTRODUCTION: Oral cutaneous sinus tracts (OCSTs) of dental origin are often initially misdiagnosed and inappropriately treated. Accurate diagnosis is especially important in cases of bisphosphonate (BP) therapy because extraction may lead to a risk of osteonecrosis. A case report of misdiagnosis related to a tooth with a vertical root fracture in an oncologic patient treated with BPs is reported here. METHODS: In 2011, a 75-year-old woman was examined at the oral medicine clinic because of pain and swelling of the left submandibular area. The patient's medical history included oral and intravenous BP therapy because she was diagnosed with metastatic breast cancer and left maxillary stage 1 antiresorptive agent-induced osteonecrosis of the jaw. The lower left odontogenic region showed no signs or symptoms, and no apical pathosis was observed on imaging. Although antibiotics were applied, clinical symptoms worsened and an OCST appeared. Intravenous antibiotic treatment was pursued. Biopsy and direct smear from fistula were not conclusive. A diagnosis of a nonexposed variant of stage 3 antiresorptive agent-induced osteonecrosis of the jaw was established. RESULTS: Symptoms resolved after 2 weeks of antibiotic treatment and reappeared a month later. Endodontic examination revealed that the origin of the OCST was tooth no. 18 caused by a vertical root fracture, and the tooth was extracted. The patient was scheduled for routine checkups because of the fact that osteonecrosis may occur in intravenous BP-treated patients. CONCLUSIONS: Early correct diagnosis can prevent unnecessary and ineffective antibiotic therapy and surgical intervention, which is not recommended in intravenous BP cases.

Revascularization: a treatment for permanent teeth with necrotic pulp and incomplete root development.

INTRODUCTION: Endodontic treatment of immature permanent teeth with necrotic pulp, with or without apical pathosis, poses several clinical challenges. There is a risk of inducing a dentin wall fracture or extending gutta-percha into the periapical tissue during compaction of the root canal filling. Although the use of calcium hydroxide apexification techniques or the placement of mineral trioxide aggregate as an apical stop has the potential to minimize apical extrusion of filling material, they do little in adding strength to the dentin walls. It is a well-established fact that in reimplanted avulsed immature teeth, revascularization of the pulp followed by continued root development can occur under ideal circumstances. At one time it was believed that revascularization was not possible in immature permanent teeth that were infected. METHODS: An in-depth search of the literature was undertaken to review articles concerned with regenerative procedures and revascularization and to glean recommendations regarding the indications, preferred medications, and methods of treatment currently practiced. RESULTS: Disinfection of the root canal and stimulation of residual stem cells can induce formation of new hard tissue on the existing dentin wall and continued root development. CONCLUSIONS: Although the outcome of revascularization procedures remains somewhat unpredictable and the clinical management of these teeth is challenging, when successful, they are an improvement to treatment protocols that leave the roots short and the walls of the root canal thin and prone to fracture. They also leave the door open to other methods of treatment in addition to extraction, when they fail to achieve the desired result.