Endodontic Access Cavity Research Articles

Assessment of coronal leakage of a new temporary light-curing filling material in endodontically treated teeth.

The aim of this study was to evaluate the sealing ability of a new temporary filling material X-Temp LC (DFL, São Paulo, SP, Brazil) compared with that obtained for Coltosol (Vigodent, Rio de Janeiro, RJ, Brazil) and Vitro Fill (DFL, Rio de Janeiro, RJ, Brazil), using a dye penetration test. Standard endodontic access cavities were prepared in 75 human premolars. The teeth were divided into five groups (n = 15 for each group), including a positive (no sealing of access cavity) and a negative control (Filtek Z350 XT, 3M, São Paulo, SP, Brazil). In the experimental groups, the access cavities were sealed with one of the three tested materials. After that, the teeth were immersed in 10% Indian ink for 14 days. The teeth were then rinsed, dried, sectioned in bucco-lingual direction and evaluated under a stereomicroscope using scores for dye penetration. Data were analyzed using Kruskall-Wallis and Student-Newman-Keuls tests (α =0.05). Positive control sections exhibited complete dye penetration and negative control had no specimen showing marginal leakage. X-Temp LC and Coltosol showed similar results, with no statistical difference between them. Vitro Fill exhibited the highest dye penetration among the experimental groups. The results of this in vitro study suggest that all temporary restorative materials exhibit some degree of marginal leakage. X-Temp LC and Coltosol, however seal better than Vitro Fill glass ionomer cement.

Accuracy of endodontic working length determination using cone beam computed tomography

To evaluate the accuracy of endodontic working length (WL) measurements by cone beam computed tomography (CBCT). Forty-two extracted human teeth were placed into three full jaw models. Preoperatively, CBCT scans of the models were performed (voxel size: 0.2 mm). Endodontic access cavities were prepared, and the coronal third of 70 root canals were pre-flared. The real WL was measured by inserting a K-file into the root canal until the tip was visible at the foramen, a silicon stopper was adjusted to the corresponding cusp tip, and the length was measured using a micrometer. CBCT WL was simply measured by tracing a line between the apical foramen and the corresponding cusp tip. When the foramen and cusp tip were not visible in one plane, the measurement was taken in two planes. To quantify measurement error, real and CBCT WLs were repeated four times by two experienced operators. Paired analysis for each variable was performed, and the mean of absolute differences and the corresponding 99% confidence intervals were calculated. The t-test was used for comparison. The coefficient of repeatability, reproducibility and interoperator agreement were <0.5 mm. CBCT measurements were accurate; the mean of absolute differences between CBCT and real WL was 0.41 mm (99% CI 0.31-0.52 mm). Using a simplified method, CBCT images of 0.2 mm voxel size can be used to accurately determine endodontic WL.

Apical extrusion of bacteria when using reciprocating single‐file and rotary multifile instrumentation systems

To evaluate ex vivo, apical bacterial extrusion associated with two reciprocating single-file systems (WaveOne and Reciproc) compared with a conventional multifile rotary system (BioRace). Forty-five human single-rooted mandibular incisors were used. Endodontic access cavities were prepared, and root canals were contaminated with an Enterococcus faecalis suspension. Following incubation at 37 °C for thirty days, the contaminated teeth were divided into three groups of 15 specimens each (G1 - Reciproc, G2 - WaveOne and G3 - BioRace). Positive and negative controls consisted of 5 infected teeth and 3 uninfected incisors that were instrumented with one of the tested NiTi systems, respectively. Bacteria extruded from the apical foramen during instrumentation were collected into vials containing 0.9% NaCl. The microbiological samples were taken from the vials and incubated in brain heart agar medium for 24 h. The resulting bacterial titre, in colony-forming units (CFU) per mL, was determined, and these data were analysed by Wilcoxon matched-pairs signed rank test and Kruskal-Wallis H-test. The level of significance was set at α = 0.05. No significant difference was found in the number of CFU between the two reciprocating systems (P = 0.41). The conventional multifile rotary system group was associated with significantly higher CFU than both of the two reciprocating groups (P = 0.01). All instrumentation systems extruded bacteria beyond the foramen. However, both reciprocating single-file systems extruded fewer bacteria apically than the conventional multifile rotary system.

Endodontic access cavity simulation in ceramic dental crowns

ObjectivesIt is proposed that a non-uniform rational B-spline (NURBS) based solid geometric model of a ceramic crown would be a flexible and quick approach to virtually simulate root canal access cavities. The computation of strain components orthogonal to surface flaws generated during the drilling would be an appropriate way of comparing different access cavity configurations. MethodsA μCT scan is used to develop a full 3D NURBS geometric solid model of a ceramic crown. Three different access cavity configurations are created virtually in the geometric model and there are then imported into proprietary finite element software. A linear analysis of the each crown is carried out under appropriate in vivo loading and the results are post-processed to carry out a quantitative comparison of the three configurations ResultsThe geometric model is shown to be a flexible and quick way of simulation access cavities. Preliminary indications are that post processed strain results from the finite element analysis are good comparators of competing access cavity configurations. SignificanceThe generation of geometric solid models of dental crowns from μCT scans is a flexible and efficient methodology to simulate a number of access cavity configurations. Furthermore, advanced post-processing of the primary finite element analysis results is worthwhile as preliminary results indicate that improved quantitative comparisons between different access cavity configurations are possible.

Antibacterial temporary restorative materials incorporating polyethyleneimine nanoparticles.

Temporary restorative materials (TRMs) often rapidly lose their dimensional stability and antibacterial properties after exposure to humidity and bacterial infection. Quaternary ammonium polyethyleneimine (QPEI) nanoparticles (NP) are long-lasting, stable, biocompatible, and nonvolatile antibacterial polymers. In the present study, we incorporated QPEI NP into standard TRMs and examined their influence on dimensional stability and their ability to reduce bacterial leakage. A modified split-chamber model was used in vitro to test calcium sulfate-based and zinc oxide-eugenol- based TRMs (Coltosol and IRM, respectively). Both materials were tested with and without 2% wt/wt incorporated QPEI NP for fluid and bacterial leakage. The calcium sulfate-based TRM displayed the lowest microleakage and highest antibacterial resistance. Two-way A NOVA analysis of the fluid transport test results showed that incorporation of 2% wt/wt QPEI NP significantly increased the sealing ability of both TRMs (P < .01). Analysis of survival curves by the Kaplan-Meier method showed that the calcium sulfate-based TRM with 2% wt/wt QPEI NP survived the bacterial load significantly more effectively than did the zinc oxide-eugenol-based TRM (P < .0001). Incorporation of 2% w/w QPEI NP may prominently improve the sealability and the antibacterial properties of TRMs. TRMs incorporating antibacterial nanoparticles may be clinically advantageous for sealing the endodontic access cavity to avoid reinfection of the root canal system during endodontic treatment.

Anaesthetic efficacy of supplemental lingual infiltration of mandibular molars after inferior alveolar nerve block plus buccal infiltration in patients with irreversible pulpitis

To investigate the effect of supplemental lingual infiltration (LI) of mandibular molars following an inferior alveolar nerve block (IANB) plus buccal infiltration (BI) in patients with irreversible pulpitis. Eighty adult patients diagnosed with irreversible pulpitis participated in this prospective study. All patients received standard IANB via injection of 4 mL of 2% lidocaine with 1 : 100,000 epinephrine. Ten minutes after the IANB, patients with numbness of the lower lip were randomly divided into two groups. In the BI group, 40 patients received supplemental BI of 0.9 mL of 4% articaine with 1 : 100,000 epinephrine. In the buccal plus lingual infiltration (BLI) group, 40 patients received supplemental BI of 0.9 mL of 4% articaine with 1 : 100,000 epinephrine and, subsequently, LIs with the same anaesthetic solution and dose. Endodontic access cavity preparation began 15 min after the IANB. Pain during treatment was recorded using a Heft-Parker visual analogue scale. Success was defined when pain was 'none' or 'mild' on endodontic access and initial instrumentation. The pain was estimated and statistically analysed by the chi-squared test (α = 0.05). The success rates for the BI and BLI groups were 70% and 62.5%, respectively. No statistical difference was found between the two groups (P = 0.478). Supplemental LIs are not recommended for administration in mandibular molars with irreversible pulpitis, because they do not improve the anaesthetic success after IANB plus BI.

Topography of the pulp chamber in the maxillary primary molars of a Tunisian children

Knowledge of the variations in pulp chamber topography is very useful to the dentist while performing endodontic access cavity in primary teeth. To determine the horizontal crown dimensions and the pulp chamber topography of shedding maxillary primary molars in a sample of Tunisian children. Forty two maxillary primary molars (24 first and 18 second molars) were used. Teeth were ultrasonically cleaned before taking morphometric measurements of the buccolingual and mesiodistal sizes. Statistical student test was used comparing the mean sizes. All the crown measurements were higher in the second molar. While the buccolingual dimension of the pulp chamber was higher in the second molar, the mesiodistal sizes were equivalent among the teeth. The thickest walls were in the buccal side of the first molar and in the mesial side of the second one. The ratio of several measurements indicate that the pulp cavity is more vestibularly and distally located in the second molar. Mesiodistal dimension of the pulp cavity is not proportional to that of the dental crown. Endodontic access cavity have to be shifted to the distal and vestibular sides from the first to the second upper molar.

A Scanning Electron Microscopic Study to evaluate the Efficacy of NaviTip FX in removing the Canal Debris during Root Canal Preparation: An in vitro Study

To evaluate the efficacy of NaviTip FX in removing the canal debris during root canal preparation using scanning electron microscopic study. Thirty single rooted teeth with completely formed apices were used in this study. Standard endodontic access cavity preparations were performed. Then the teeth were randomly divided into two groups: groups 1 and 2 of 15 teeth each group. For group 1, NaviTip FX (brush covered needle) was used to irrigate the canal with 5.25% sodium hypochlorite after each instrument use. For group 2, NaviTip (brushless needle) was used for irrigation following each instrument use. ProTaper rotary files were used for the canal preparation. The teeth were then cleaned and dried before splitting them into two halves. The half with most visible part of the apex was used for scanning electron microscopic evaluation. The results were statistically analyzed using the Mann-Whitney U-test at significance level p < 0.005. The mean values for coronal and middle third of group 1 showed lower debris scores than group 2 and this difference was statistically significant at a p-value 0.01 and 0.05 respectively, but no significance difference between them at the apical third at a p-value of < 0.05. The NaviTip FX (brush covered needle) showed effectively better canal wall debris removal than the NaviTip (brushless needle).

Single-visit endodontic management of iatrogenic supracrestal root perforation associated with dual sinus using MTA and collagen

Iatrogenic perforation is usually an undesired complication that results in an artificial communication between the root canal system to the supporting tissues of the teeth or to the oral cavity. It can occur during preparation of endodontic access cavities and exploration of calcified canal orifices. Successful treatment depends on the proper diagnosis and immediate sealing of the perforation site to eliminate the risk of infection. On the basis of the physical and biologic properties, mineral trioxide aggregate (MTA) has shown superior sealing ability and is suitable for closing the perforation site. The purpose of this case report is to describe the successful orthograde retreatment of iatrogenically perforated lower central incisor associated with dual sinuses. The perforation site was cleaned with 5.25% sodium hypochlorite and 0.9% normal saline solution and sealed with MTA with an internal collagen matrix. Finally, the tooth was endodontically treated and coronally restored with composite resin. After 6 and 12 months of follow-up, the absence of periradicular radiolucent lesion, disappearance of dual sinus, pain and swelling indicated a successful outcome of non-surgical sealing of the perforation.

Repair of Furcal Perforation with Mineral Trioxide Aggregate: Case Report

Furcal perforation is usually an undesired complication that can occur during preparation of an endodontic access cavities or exploring canal orifice of multirooted teeth. Inadequacy of the repair materials has been a contributing factor to the poor outcome of repair procedures. On the basis of the recent physical and biologic property studies of the relatively new introduced mineral trioxide aggretate, this material maybe be suitable for closing the communication between the pulp chamber and the periodontal tissues. There are few reports on repair of furcal perforation with MTA in molar teeth. The purpose of this case report was to describe the treatment of furcal perforation using MTA in molar teeth. The perforations were cleaned with NaOCl and saline solution, the tooth was endodontically treated and perforation was sealed sealed with MTA and coronally restored with posterior high strength glass ionomer cement and metal veneer crown. After 6 months, the absence of any radiolucency in the furcation area, pain along with functional tooth stability indicated a successful outcome of sealing perforation in 1 case.

Effect of Premedication with Ibuprofen and Dexamethasone on Success Rate of Inferior Alveolar Nerve Block for Teeth with Asymptomatic Irreversible Pulpitis: A Randomized Clinical Trial

IntroductionThe aim of this study was to compare 2 kinds of anti-inflammatory medicines (ie, dexamethasone and ibuprofen) with a placebo according to their effects on the success rates of an inferior alveolar nerve block (IANB) for the endodontic treatment of mandibular molars with irreversible pulpitis. MethodsA total of 165 patients were divided into 3 groups of 55 patients each and were given a capsule of the same color and size (ie, a placebo of lactose powder, 400 mg ibuprofen, or 0.5 mg dexamethasone). One hour after the oral administration of the capsules, all the patients received a standard IANB. In patients with a successful IANB, the teeth were examined with a cold pulp test. Patients were asked to assess their pain using the visual analog scale. Then, endodontic access cavity preparation was initiated. In case of pain during the treatment, the patients were asked to rate the pain on the visual analog scale. Success was defined as no or mild pain during treatment. The chi-square test and analysis of variance were used to compare qualitative and quantitative data among the groups. ResultsNo significant differences were found regarding the sex of the patients in the 3 groups (P > .05). The dexamethasone group showed significantly higher success rates compared with the placebo group (P = .001). There were no significant differences between the ibuprofen and placebo groups (P = .055) or the dexamethasone and ibuprofen groups (P = .34). ConclusionsPremedication with dexamethasone increased the success rate of an IANB in mandibular molars with asymptomatic irreversible pulpitis.

Influence of resin-based composite restoration technique and endodontic access on cuspal deflection and cervical microleakage scores

ObjectivesTo assess cuspal deflection and cervical microleakage of mesio-occlusal-distal cavities in standardised premolar teeth restored incrementally with resin-based composite (RBC) placed horizontally or obliquely and with endodontic access cavities (with and without gutta percha and epoxy resin sealer obturation). Materials and methodsThirty-two teeth were allocated to four groups (n=8) and RBC restored in eight horizontal (Group A) or oblique increments (Groups B–D) using a quartz-tungsten-halogen light curing unit. The dependent variable for Groups B–D was endodontic access (none (Group B), obturated without (Group C) and with gutta percha and epoxy resin sealer (Group D)). Cuspal deflections were recorded post-irradiation using a twin channel deflection measuring gauge. Following restoration, the teeth were thermocycled, immersed in fuchsin dye, sectioned and examined for cervical microleakage. ResultsTukey's post hoc tests identified a significant decrease in total cuspal deflection for the horizontal (p=0.015) compared with the oblique placement technique. No significant difference in total cuspal deflection was evident between Groups B and D restored teeth (p>0.318) or in cervical microleakage score between Groups A and D (p=0.575). SignificanceDeformation is proportional to the cubed power of the length of a uniform cantilever beam and although a crude approximation of cuspal deformation, the reduction in the effective cusp length therefore significantly reduced the deflection in the MOD cavities when the horizontal rather than the oblique incremental restoration technique was employed.

Nonsurgical Endodontic Retreatment of Advanced Inflammatory External Root Resorption Using Mineral Trioxide Aggregate Obturation

Inflammatory external root resorption is one of the major complications after traumatic dental injury. In this case report, we describe treatment of a maxillary central incisor affected by severe, perforating external root resorption. An 18-year-old patient presented with a previously traumatized, root-filled maxillary central incisor associated with pain and sinus tract. Radiographic examination revealed periradicular lesion involving pathologic resorption of the apical region of the root and lateral root surface both mesially and distally. After removal of the root canal filling, the tooth was disinfected with intracanal triple antibiotic paste for 2 weeks. The antibiotic dressing was then removed, and the entire root canal was filled with mineral trioxide aggregate. The endodontic access cavity was restored with composite resin. After 18 months, significant osseous healing of the periradicular region and lateral periodontium had occurred with arrest of external root resorption, and no clinical symptoms were apparent.

Effect of doxycycline on the apical seal of the retrograde filling materials : An ex - vivo study

Objectives: To evaluate the efficiency of Doxycycline Hydrochloride on the apical seal of retrograde filling materials. Materials and methods: Sixty freshly extracted human maxillary central incisors were selected. Endodontic access cavity preparation was done and the canals were located. Cleaning and shaping of root canals was done using k-files upto size 45. The root canals were obturated with gutta percha in lateral condensation technique. The apical 2 mm were resected, and a retrograde preparation was made to a depth of 3mm with a no:331 bur. The teeth were divided into 6 groups of 10 teeth each. The apical cavities in Group A, B and C were irrigated with saline as control groups. The cavities in Group D, E and F were irrigated with doxycycline HCl, 100 mg/ml as experimental group. The apical cavities in Group A and D were filled with IRM, Group B and E were filled Type-II GIC, Group C and F were filled with MTA. The surfaces of all the teeth except the apical 3mm were sealed using two coats of nail polish and one coat of sticky wax. All the teeth were then immersed in India ink dye and were subjected to thermocycling for 7 days. The teeth were then longitudinally sectioned and the degree of linear dye penetration was measured using stereomicroscope The mean results were statistically evaluated by Student-Newman-Keuls test and ANOVA. Results : MTA and GIC retrograde filling materials allowed significantly less dye leakage than IRM in both experimental and control groups, especially when preceded with doxycycline irrigation of the apical cavities. Conclusion: Irrigation of the apical cavities with Doxycycline Hydrochloride significantly improved the apical seal of retrograde filling materials. Abbreviations: MTA-Mineral Trioxide Aggregate. GIC-Glass ionomer cement. IRM-Intermediate restorative material.

Endodontic management of maxillary first molar with five canals: Report of a case aided with spiral computed tomography

Introduction. Maxillary first molars have shown substantial dissimilarity regarding their number of roots, canals and morphology. Most commonly, it has three roots and four canals, two mesiobuccal, one distobuccal and one palatal canal. The incidence of second mesiobuccal canal has been reported between 18% and 96.1% while the incidence of two distobuccal canals was found in 1.64% to 9.50% of cases. Periapical (PA) radiography has been commonly used to determine root canal anatomy even though it is two-dimensional representation of a three-dimensional object. Advanced diagnostic methods as spiral computed tomography (SCT) provide three-dimensional images useful to determine complex canal morphology. Case Report. A 31-year-old male patient was referred for endodontic treatment of the maxillary right first molar. Endodontic access cavity revealed two canal openings in each of the mesiobuccal and distobuccal roots and one canal in the palatal root later confirmed using the SCT and conventional PA radiography. The canals were instrumented using crown down technique with ProTaper NiTi rotary files. Obturation was performed using single gutta-percha cone and AH Plus paste. The patient remained asymptomatic during the regular checkups. Conclusion. Knowledge, detection and management of complex canal anatomy is of the foremost importance in endodontics since missed canals are one of well recognised reasons for endodontic treatment failure.

Root canal treatment of bilateral three-rooted maxillary first premolars

In endodontics, several anatomic variations occur in teeth, both externally and in the internal root morphology, which play a very significant role in the diagnosis and treatment outcome. A thorough knowledge of the root canal anatomy, careful interpretation of the angled radiographs, proper endodontic access cavity preparation, and exploration of the root canal are the prerequisites for endodontic success. In a maxillary first premolar, it is rare to find extra roots and canals, and the aim of the present article is to report a case about the successful diagnosis and clinical management of bilateral three-rooted maxillary first premolars, with three independent root canals.

Coronal microleakage of four temporary restorative materials in Class II-type endodontic access preparations

Objectives: The purpose of this study was to evaluate the microleakage of 4 temporary materials in teeth with Class II-type endodontic access preparations by using a glucose penetration model. Materials and Methods: Glucose reaction test was performed to rule out the presence of any reaction between glucose and temporary material. Class II-type endodontic access preparations were made in extracted human premolars with a single root (n = 10). Each experimental group was restored with Caviton (GC), Spacer (Vericom), IRM (Dentsply-Caulk), or Fuji II(GC). Microleakage of four materials used as temporary restorative materials was evaluated by using a glucose penetration model. Data were analyzed by the one-way analysis of variance followed by a multiplecomparison Tukey test. The interface between materials and tooth were examined under a scanning electron microscope (SEM). Results: There was no significant reaction between glucose and temporary materials used in this study. Microleakage was significantly lower for Caviton and Spacer than for Fuji II and IRM. SEM observation showed more intimate adaptation of tooth-restoration interfaces in Caviton and Spacer than in IRM and Fuji II. Conclusions: Compared to IRM and Fuji II, Caviton and Spacer can be considered better temporary sealing materials in Class II-type endodontic access cavities.

Coronal microleakage for readymade and hand mixed temporary filling materials.

The purpose of this in vitro study was to evaluate the sealing ability of the readymade temporary filling and hand mixed materials by assessing coronal microleakage. Standardized access cavities were prepared in 80 intact human permanent premolar teeth. They were divided randomly into four experimental groups (n=20). The teeth were restored using one of the temporary materials including Cavisol, Litrak, Zinc phosphate cement, Zinconol (IRM). Thermocycling was applied on the specimens. Methylene blue dye was applied and penetration was evaluated under stereomicroscope. Grading of the microleakage pattern was from 1 to 3, with 3 providing the best seal. Results were analyzed using one-way ANOVA test (P<0.05). Microleakage of Cavisol and Litrak samples achieved grade 3; whereas zinc phosphate cement and Zinconol samples absorbed the dye into the bulk of the materials. Cavisol was found to exhibit the best seal amongst the four tested materials followed by Litrak, zinc phosphate cement, and Zinconol. There was a statistically significant difference in the microleakage scores obtained between the materials (P<0.01). Among the four materials tested, readymade temporary filling provided the best sealing ability over hand-mixed. This study emphasizes the importance of correct placement and sufficient thickness of temporary filling materials in endodontic access cavities to ensure a tight seal.

Access cavity preparation training using haptic virtual reality and microcomputed tomography tooth models

To evaluate the effectiveness of haptic virtual reality (VR) simulator training using microcomputed tomography (micro-CT) tooth models on minimizing procedural errors in endodontic access preparation. Fourth year dental students underwent a pre-training assessment of access cavity preparation on an extracted maxillary molar tooth mounted on a phantom head. Students were then randomized to training on either the micro-CT tooth models with a haptic VR simulator (n = 16) or extracted teeth in a phantom head (n = 16) training environments for 3 days, after which the assessment was repeated. The main outcome measure was procedural errors assessed by an expert blinded to trainee and training status. The secondary outcome measures were tooth mass loss and task completion time. The Wilcoxon test was used to examine the differences between pre-training and post-training error scores, on the same group. The Mann-Whitney test was used to detect any differences between haptic VR training and phantom head training groups. The independent t-test was used to make a comparison on tooth mass removed and task completion time between the haptic VR training and phantom head training groups. Post-training performance had improved compared with pre-training performance in error scores in both groups (P < 0.05). However, error score reduction between the haptic VR simulator and the conventional training group was not significantly different (P > 0.05). The VR simulator group decreased significantly (P < 0.05) the amount of hard tissue volume lost on the post-training exercise. Task completion time was not significantly different (P > 0.05) in both groups. Training on the haptic VR simulator and conventional phantom head had equivalent effects on minimizing procedural errors in endodontic access cavity preparation.

Influence of cusp coverage on the fracture resistance of premolars with endodontic access cavities

To assess the influence of cusp reduction and coverage with composite resin on the fracture resistance of premolars with prepared access cavities. Endodontic access cavities were prepared in 60 premolar teeth that were divided into four test groups: R1, R2, R3 and NR (n=15). In all test groups, MOD cavities were prepared and extended towards one of the cusps. The remaining cusp-wall thickness was: 1-1.5 mm in R1, 1.5-2 mm in R2 and 2-3 mm in both R3 and NR groups. In addition, in group R1, R2 and R3 the same cusp was reduced in height to 3.5 mm. Cuspal coverage and MOD restorations were performed using composite resin. Ten intact premolars served as positive controls and another ten MOD-prepared unrestored premolars as negative controls. Teeth were submitted to cyclic fatigue of 1.2 million cycles. A compressive load was applied 30° to the long axis of the teeth until fracture. Fracture loads were recorded and the means and the Confidence Intervals were compared. The mean fracture resistance of each of the cusp-reduced groups R1, R2 and R3 (603, 712 and 697 N, respectively) was significantly higher than the non-reduced cusp group (305 N) and was comparable to the intact-premolar group (653 N). Cusp reduction and coverage with composite resin significantly increased the fracture resistance of premolar teeth with MOD and endodontic access cavities.