Objective: The purpose of this study was to assess the restorative choices for pulpal therapy by members of the Australian and New Zealand Society of Paediatric Dentistry (ANZSPD).
Methods: Members of the ANZSPD were sent an online survey asking about the procedures that they per- formed and their choice of dental materials.
Results: The respondents were 31 general dentists (GD) and 55 specialist paediatric dentists (PD). Materials used for indirect pulp capping included calcium hydroxide [Ca(OH)2] cement (CHC), glass ionomer cement or resin-modified glass ionomer cement (GIC/RMGIC), Ca(OH)2 paste (CHP) and mineral trioxide aggregate (MTA). Materials for direct pulp capping included MTA, CHP and CHC. Materials and techniques used for pul- potomy included MTA, ferric sulphate, formocresol and diathermy, CHP and CHC. GD and PD were similar in their choice of materials. However, there was no preferred product for pulp therapy. Most GD learnt how to use MTA from CPD lectures, while some PD learnt how to use MTA from their postgraduate training as well as CPD lectures. Many GD and PD did not have hands-on training from their education on how to use MTA (GD: 80%, PD: 43%). Most would like to attend hands-on MTA courses (GD: 86%, PD: 65%).
Conclusion: There was no clear preferred product for the various types of pulp therapy in paediatric dentist- ry. Education appears to be the major barrier to the use of MTA rather than the cost of MTA.

Objective: The purpose of this study was to determine the ability of a methacrylate resin dentin bonding agent to adhere to the dentin surfaces of prepared and conditioned root canals with either 32% phosphoric acid (PA) or 17% ethylenediaminetetraacetic acid (EDTA).
Methods: Prior to the application of the methacrylate resin, the root canals of 54 intact, caries-free, sin- gle-rooted, de-crowned, extracted human maxillary incisor and canine teeth were endodontically prepared and conditioned with either 32% PA or 17% EDTA or with distilled water as the unconditioned control. The resin-treated roots were cross-sectioned at three levels and scanning electron microscope (SEM) imaged for circumferential views of the root canals at 60-90× magnification and site-specific views at 250× magnification, and then randomly coded for independent and blind evaluation by four calibrated examiners. The circumfer- ential surface of the root canals that showed no resin adhesion were digitally measured and subtracted from the digitally measured total root canal circumference, and resin adhesion was expressed as a percentage of the circumference.
Results: The mean percentages of resin adhesion were 97% for the PA group, 94% for the EDTA group, and 76% for the control group. There were statistically significant differences among the PA, EDTA, and control groups.
Conclusion: Root canals conditioned with 32% PA or 17% EDTA had more resin adhesion than unconditioned root canals. Root canals conditioned with 32% PA had more resin adhesion than those conditioned with 17% EDTA.

A comprehensive knowledge and understanding of root canal anatomical variations are essential for success- ful root canal treatment. Mandibular molar teeth show considerable variations in their external and internal radicular morphology that require special attention from dental practitioners to provide the best clinical out- comes to the patients. This report aims to present root canal treatment of a mandibular first molar that has six separate root canals (three root canals in the mesial roots and three in the distal roots [236 M3 D3]). This report points out the importance of proper exploration for identifying additional canals in mandibular molars.

Objective: The purpose of this ex vivo study was to evaluate the filling material removal ability, and the time required to perform this procedure, of reciprocating and conventional rotary systems when associated with passive ultrasonic irrigation.
Methods: The palatal roots of 40 maxillary molars were submitted to root canal preparation and filling. The desobturation of root canals was initially performed with Largo burs in the coronal portion (4 mm) to drill the gutta-percha and to facilitate the action of the instruments used then. Next, the palatal roots were randomly distributed (n=10) according to the systems and irrigation protocols used for filling material removal: ProTa- per universal retreatment (PTR), PTR+passive ultrasonic irrigation (PUI) (PTR+PUI), Reciproc system (RS), and RS+PUI. Passive ultrasonic activation was performed in the root canals completely filled with 2.5% sodium hypochlorite solution using a smooth and straight ultrasonic tip, coupled to a low-power (20%) ultrasonic device for 1 min (3 cycles of 20 s). After retreatment, the roots were longitudinally sectioned to the remaining filling material quantification using an operating microscope. Environmental scanning electron microscopy (ESEM) micrographs at 97, 105, and 250 X magnifications were also taken to evaluate the quantity of filling material present at the apical portion of the palatal roots.
Results: The RS group presented greater quantity of filling material attached to the root canal walls than the other groups (P>0.05). PTR+PUI and RS+PUI groups were statistically similar (P>0.05). Reinstrumentation of root canals using RS was faster than PTR, irrespective of the irrigation protocol used (P>0.05).
Conclusion: The association between PUI and the different systems for reinstrumentation yielded greSater filling material removal. The reciprocating system was faster.

Objective: This study sought to evaluate the effect of the penetration of an epoxy resin-based root canal sealer into dentin tubules on the force required to dislodge the root canal filling.
Methods: Sixty extracted human central incisors with single canals were decoronated, instrumented, and filled with gutta-percha and AH Plus sealer labeled with 0.1% rhodamine B dye. The roots were further sec- tioned horizontally at 3, 6, and 8 mm from the apex. The coronal surfaces of the resulting 180 slices were evaluated using confocal laser scanning microscopy to measure the amount of sealer that penetrated into the dentin tubules. To quantify the force required to dislocate the root filling material, the root fillings of the slices were subjected to a dislodgement resistance test (push-out). Spearman’s rho correlation test was fur- ther used to test the correlation between the push-out bond strength and sealer penetration into the dentin tubules (P<0.05).
Results: No significant correlation was observed between sealer penetration into the dentin tubules and the force required to dislodge the root canal filling (P=0.626).
Conclusion: Following the results of this study, the penetrating ability of the AH Plus sealer into dentin tu- bules has no correlation with the force required to dislodge the root canal filling.

In some regions, endodontists are increasingly placing implants in their daily practice. Endodontists have been proponents of the use of a dental dam during root canal treatment. It is beneficial to reduce the inges- tion/aspiration of dental instruments during implant placement. It may be beneficial to reduce the bacterial load during implant placement procedures because biofilm formation on implants can lead to failure. A den- tal dam may help reduce the ingress of oral bacteria during implant placement.
This case report demonstrates the use of a dental dam during the surgical placement of a dental implant. A literature review is presented that includes the history and rationale for the use of dental dams during various dental procedures. It also reviews the risks of aspirating/ingesting implant instruments.
The use of a dental dam during implant placement offers certain operator conveniences, while also providing a safer field with less chance of instrument swallowing. It is expected that the technique offers a less bacte- ria-laden operating field due to the reduction in salivary ingress into the surgical site.

Objective: The purpose of this study was to determine the efficacy of different irrigants and irrigation proto- cols in the removal of gutta-percha and sealer from simulated un-instrumented areas.
Methods: Eighty-four uniradicular teeth were used. After standardizing working length (WL) and preparing the glide path, coronal flaring was performed. The instrumentation phase was completed with ProFile rotary instruments up to size #35 LightSpeed LSX. Roots were split into halves: in one of them, a groove was pre- pared in the apical 6 mm. In the opposite one, 5 depressions were made (at 2, 4, 6, 8 and 10 mm). Irregularities were filled with AH Plus sealer and flowable gutta-percha. The Efficacy of sodium hypochlorite (NaOCl) and chloroform in removal of material and the effect of positive pressure (PP), passive ultrasonic irrigation (PUI) (one or three cycles) and paper points were analysed with the chi-square test.
Results: Delivery by PP did not eliminate the obturator material from any artificial depression. Chloroform, when activated, demonstrated a significant linear trend in the amount of gutta-percha removed at all tested levels (P<0.01). The use of paper points after passive delivery of chloroform increased significantly the remov- al of gutta-percha in the groove and at 4 and 10 mm (P<0.05). Three cycles of PUI and chloroform showed significantly fewer remnants of gutta-percha (P<0.01).
Conclusion: Positive pressure was not effective in the removal of obturator materials with any of the tested irrigants. Chloroform delivered by PP in combination with paper points obtained a better cleaning efficacy, although its activation using PUI for three cycles of 20 s showed the best cleanliness.

Objective: This study evaluates the efficacy of passive ultrasonic irrigation (PUI) in removing root canal filling material from endodontically treated teeth after using one of two reciprocating systems, Reciproc (VDW, Munich, Germany) or WaveOne (Dentsply Maillefer, Ballaigues, Switzerland), or one nickel-titanium (NiTi) rotary system, ProTaper Universal Retreatment (Dentsply Maillefer).
Methods: One hundred and twenty straight root canals of extracted human maxillary incisors were instrumented and then obturated. The specimens were divided into six groups (n=20) as follows: Group R, Reciproc R25 instrument without PUI; Group W, WaveOne Primary instrument without PUI; Group PT, ProTaper Universal Retreatment system without PUI; Group R-PUI, Reciproc R25 with PUI; Group W-PUI, WaveOne Primary with PUI and Group PT-PUI, ProTaper Universal Retreatment system with PUI. After removing the filling material, the teeth were cleaved longitudinally and photographed. The total canal space and remaining material were quantified with the aid of an imaging software tool. The Kruskal-Wallis test was used to identify significant differences between the groups.
Results: No statistically significant differences (P>0.05) in residual filling material were observed between the groups.
Conclusion: The use of PUI did not improve the removal of filling material from the root canals, regardless of the previously used instrumentation system.

Objective: Direct pulp capping involves covering exposed pulp to preserve its viability. Calcium hydroxide materials have traditionally been the most commonly used pulp capping compounds; however, they can be toxic, and their success rate in pulp capping is variable. Recently, the compound mineral trioxide aggregate (MTA) has gained wide use for pulp capping. One advantage of MTA is its low toxicity. However, the effects of MTA and calcium hydroxide compounds on the toxicities of other dental materials have not been tested. The aim of this study is to determine whether different pulp capping materials can alter the toxicity of composite restoration materials.
Methods: We used cultured human dental pulp cells to test the toxicities of the calcium hydroxide pulp capping material Dycal and MTA. We then tested the abilities of these compounds to alter the toxicity of the composite materials Durafill and Flow Line and to induce oxidative stress.
Results: As expected, Dycal demonstrated toxicity, while MTA did not. However, when cells were exposed to subtoxic amounts of Dycal or MTA, then exposed to Durafill or Flow Line, changes in the composite materials induced toxicity. Treatment with Dycal had no effect on the toxicity of Durafill, but significantly attenuated the toxicity of Flow Line; meanwhile, MTA significantly enhanced the toxicity of Durafill but had no effect on the toxicity of Flow Line. Early changes in oxidative stress were correlated with later changes in cell death. Statistical calculations were performed using one-way ANOVA followed by the Bonferroni t-test. P-values <0.05 were considered to indicate significant differences.
Conclusion: The results suggest that when choosing a pulp capping material, one factor that should be considered is the impact of that compound on the toxicity of the composite material used for restoration.

Tooth avulsion represents the most complicated dental injury, and the classic treatment is tooth replanta- tion. The most common sequelae are pulp canal calcification (PCC) and pulp necrosis. The presence of pulp necrosis after PCC is reported in up to 30% of the cases and is a challenge due to the difficulty of endodontic treatment. This case report describes the surgical treatment of a replanted tooth presenting PCC and periapi- cal pathology eight years after the trauma. An endodontic surgery was performed to remove the apical gran- uloma, to prepare the apical root, and to seal the apical region with an endodontic cement. In a three-year follow-up, there was an absence of inflammatory signs and symptoms or apical lesion. This report shows the importance of close follow-up after dentoalveolar injuries. After the initial dental trauma and its consequenc- es to pulpal tissues, the executed procedures allowed a favourable outcome.

The purpose of this article is to present the treatment of an odontogenic cutaneous sinus tract with exu- berant extraoral granulation tissue and its successful endodontic treatment and follow up with Cone-Beam Computed Tomography (CBCT). In this case, a 31-year-old woman was referred for management of a reddish nodule on her chin. Previous surgical and antibiotic intervention by the dermatologist had not resolved the problem. Profound clinical and radiological examination (including CBCT) revealed apical periodontitis of tooth 32 to be the cause of the recurring cutaneous sinus tract. Conservative non-surgical root canal treat- ment was performed. With the aid of a topical corticosteroid and supplemental antibiotic therapy, healing of the apical periodontitis and resolution of the granulation tissue was evident after 1 year both clinically and radiographically. This case report emphasises the need for more awareness by dermatologists and other medical practitioners for the differential diagnosis of extraoral sinus tracts. Correct diagnosis of the dental cause can prevent unnecessary and multiple antibiotic and surgical interventions. Antibiotic therapy should never be administered without addressing the underlying dental cause. Conservative non-surgical endodon- tic treatment is the treatment of choice for an extraoral sinus tract of endodontic origin.

Objective: The aim of this study was to evaluate the effect of a calcium hydroxide (CH) dressing on the tu- bular penetration of two endodontic sealers, AH Plus (Dentsply Maillefer, Ballaigues, Switzerland) and MTA Fillapex (Angelus, Londrina, Brazil).
Methods: Seventy-two mandibular premolars with a single root canal were prepared with ProFile.04 rotary instruments (Dentsply Maillefer) and divided into four groups. In two groups, an intracanal CH dressing was placed for 15 days. The obturations were performed with lateral condensation of gutta-percha in combina- tion with one of the tested sealers. The roots were transversely sectioned at the apical and middle levels. The percentage of sealer penetration in the root canal walls and the percentage of impregnated dentin area in the transverse sections were obtained using confocal laser scanning microscopy. Statistical analysis was performed using one-way analysis of variance (ANOVA) and Games-Howell test.
Results: The CH dressing reduced the mean value of tubular penetration in the middle third of teeth obturat- ed with AH Plus (P<0.01), whereas no difference was observed at the apical sections for both sealers. Conclusion: The CH dressing did not interfere with the apical penetration of both tested sealers, however, decreased the tubular penetration in the middle third of the AH Plus root canal fillings. Overall, MTA Fillapex presented higher tubular penetration than AH Plus obturations.

Objective: The aim of this study was to evaluate the obturation of mesial root canals of mandibular first mo- lars performed with different filling techniques and materials (gutta-percha and resilon).
Methods: Seventy-eight mesial root canals of human mandibular first molars were prepared using the K3 rotary system, and the apical preparation was set up to size 35.04. The root canals were obturated with single cone, System B, Thermafil and Real Seal 1 techniques using either gutta-percha/ThermaSeal Plus (n=13) or Resilon/Real Seal SE (n=13). Rhodamine B dye was incorporated into the sealers. Each specimen was horizon- tally sectioned at 2 milimeters (mm), 4 mm and 6 mm from the apex, and the samples were examined under a stereomicroscope to evaluate the presence and type of isthmuses and the percentage areas of gutta-percha/ Resilon, sealer and voids. Confocal laser scanning microscopy (CLSM) was used to evaluate the sealer pene- tration into dentinal tubules. The Kruskal-Wallis and Dunn’s tests were used to analyse the stereomicroscope data, while the ANOVA and Tukey tests were used to analyse the CLSM data (P<0.05).
Results: Thermafil and Real Seal 1 fillings showed more gutta-percha/Resilon and less sealer (P<0.05) at the 2 mm level, but the percentage of voids was similar in all groups (P>0.05). At the 4 mm level, more sealer (P<0.05) was found in the single cone groups using both materials. The System B groups exhibited better performance at the 6 mm level. The percentage of sealer penetration showed no statistically significant dif- ferences among the obturation techniques for all evaluated levels. Similar results (P>0.05) were found for both material/sealers.
Conclusion: None of the materials or techniques completely filled the mesial root canals of mandibular mo- lars, but the plasticised techniques were more efficient. The obturations using both materials and sealers were similar.

Objective: This preliminary study aimed to evaluate the antimicrobial activity, flow and radiopacity of end- odontic sealers with nanostructured silver vanadate decorated with silver nanoparticles (AgVO3).
Methods: The minimum inhibitory concentration (MIC) of AgVO3 was evaluated against Enterococcus faeca- lis, Pseudomonas aeruginosa and Escherichia coli. Specimens were prepared from the following endodontic sealers: AH Plus (DENTSPLY DeTrey GmbH, Konstanz, Germany), Sealapex (Sybron Endo, Orange, CA, USA), Sealer 26 (DENTSPLY, Petrópolis, Brazil) and Endofill (DENTSPLY, Petrópolis, Brazil), with concentrations of 0%, 2.5%, 5% and 10% of AgVO3. Agar diffusion was used to evaluate the materials after 48 hours and 7 days (n=6). Flow (n=6) and radiopacity (n=9) were evaluated. The data were analysed by analysis of variance (ANOVA) and the Tukey honestly significant difference (HSD) (α=0.05).
Results: The MIC of AgVO3 was 500 μg/mL for E. faecalis and 31.25 μg/mL for P. aeruginosa and E. coli. The AgVO3 did not influence the antimicrobial activity of AH Plus against E. faecalis (P>0.05) but did promote this activity for Sealapex (P<0.01). Moreover, this activity increased for Endofill from 2.5% and for Sealer 26 from 5% (P<0.05). Against P. aeruginosa, only AH Plus and Endofill 10% inhibited zone formation (P<0.01). The anti- microbial activity of Endofill increased from 2.5% against E. coli (P<0.01). Sealapex 5% and 10% (P<0.01), Seal- er 26 10% and AH Plus promoted antimicrobial activity against E. coli. An increase in the zone of inhibition occurred between 48 hours and 7 days in the Sealapex 10% and Endofill 5% groups against E. coli. The flow of AH Plus and Endofill decreased with the increase of AgVO3 (P<0.05), and the flow of Sealer 26 and Sealapex was not affected (P>0.05). The radiopacity of AH Plus increased with AgVO3 (P<0.05). Endofill 5% and 10% did not differ from the control Endofill (P>0.05). The incorporation of AgVO3 did not influence the radiopacity of Sealer 26 (P>0.05). The incorporation of 2.5% and 5% AgVO3 reduced the radiopacity of Sealapex (P<0.05). Conclusion: Adding AgVO3 may increase the antimicrobial effect of endodontic sealers without major changes in their physicochemical properties.

An 8-year-old girl sustained an accidental traumatic avulsion of her right maxillary permanent central incisor. She arrived with her mother at a hospital dental clinic with the right maxillary central incisor tooth wrapped in a wet paper towel over 1 hour after the injury. Replantation was accomplished without root surface alter- ation or root canal intervention. Clinical and radiographic follow-up examinations for over 1 year revealed continued root growth and apical development of the replanted avulsed immature maxillary central incisor with no signs or symptoms of pulpal or periapical pathosis. Excellent outcomes were achieved for periodon- tal ligament reattachment without removal of the periodontal membrane and pulp revascularization with- out endodontic intervention.

Objective: The aim of this study was to evaluate the influence of root canal curvature (curved and straight root canals), prepared using reciprocating and rotary files, on wall cleanliness during root canal treatments. Methods: Thirty curved and 30 straight human root canals were prepared using ProTaper (Dentsply), Pro- Taper Next (Dentsply) and Reciproc files (Dentsply) (n=20/group). The roots were split longitudinally and observed using a scanning electron microscope. Six micrographs were obtained at 1, 3 and 5 mm from the working length (WL). Two blinded observers scored the amount of debris. Mean debris scores were com- pared using a non-parametric the Mann-Whitney U test or Kruskal-Wallis test, and a Bonferroni correction was used for multiple comparisons.
Results: Considering all the shaping systems together, the debris scores were lower in curved root canals (P<0.05). Reciproc and ProTaper Next performed better than ProTaper in straight canals (P<0.05). No differ- ence was found between ProTaper Next and Reciproc regardless of the canal curvature or distance from the WL. Considering all the shaping systems together, cleanliness increased when pulling away from the WL. Conclusion: The anatomical configuration of the root canal influences the quality of cleaning by shaping instruments regardless of the instrument kinematics during endodontic procedures. In every circumstance, the last millimetres of the apical third remain the most difficult area to clean.

Objective: This study aimed to evaluate the accuracy and reliability of periapical radiographs obtained with two different projections in determining the cleanliness of root canals in endodontic retreatment using the sectioned roots as a gold standard.
Methods: The amount of residual root-filling material after endodontic retreatment procedures in 42 roots was assessed in radiographs and in microscopic photographs of the sectioned roots by five observers. Further- more, the cleanliness of 80 roots was assessed based on orthogonal and mesio-angulated radiographs. Four parameters were used for the evaluation of cleanliness. Wilcoxon signed-rank tests and percentage agreement calculations were used for comparisons between the radiographs and the gold-standard observations and be- tween the orthogonal and mesio-angulated radiographs, respectively. Intra- and interobserver reproducibility was tested using Kappa statistics and intra-class correlation tests. The statistically significance level was 0.05 Results: In general, significantly more residual root-filling material was detected in the photographs of the split roots (gold standard) than in the radiographs. Comparing orthogonal and eccentric projections, only slight differences in cleanliness were found. The intraobserver reproducibility was fair to almost perfect for radiographs and microscopic photographs. For all parameters, the reproducibility was better for the radiographs than for the microscopic photo- graphs. The interobserver variability ranged from fair to almost perfect agreement for the radiographs. Conclusion: The accuracy of periapical radiographs was poor in determining the cleanliness of root canals after endodontic retreatment, whereas the reliability of the radiographs was fair. A mesio-angulated projec- tion did not contribute essentially to the detection of residual root-filling materials.

Objective: Different single-file instruments and kinematics have been introduced on the market. It is important to know the cyclic fatigue performance of these instruments in these new kinematics such as reciprocation of Optimum Torque Reverse (OTR) motion. The aim of this study was to evaluate the resistance to cyclic fatigue of F6 SkyTaper and OneShape used in continuous rotation (proper rotation) or in reciprocating OTR motion.
Methods: A total of forty-eight nickel-titanium files were tested. Twenty-four instruments of both brands were divided into two groups (n=12) on the basis of the motion tested: continuous rotation (group 1) or reciprocating OTR motion (group 2). Resistance to cyclic fatigue was determined by recording time to fracture (TtF) in a stainless steel artificial canal with a 60° angle of curvature and 5 mm radius of curvature. Data were analysed by two-way analysis of variance and post-hoc Bonferroni tests for multiple comparisons with P<0.05 as the level of significance.
Results: F6 SkyTaper showed higher TtF compared with OneShape, both in continuous and in OTR motion (P<0.0001). The two tested instruments showed higher cyclic fatigue resistance in reciprocating OTR motion than continuous rotation (P<0.0001).
Conclusions: OTR motion significantly improves cyclic fatigue resistance of the tested instruments. In addition, F6 SkyTaper showed higher cyclic fatigue resistance than OneShape in both motions.

Objective: This study used microcomputed tomography (micro-CT) to compare the volumes of voids and gaps in curved root canals instrumented and filled using various techniques.
Methods: Twenty extracted mandibular first molars with two curved mesial root canals were used. Root canals were instrumented using a self-adjusting file (SAF) or Revo-S file system. For standardization, mesio- buccal canals were instrumented with SAF and mesiolingual canals were instrumented with Revo-S in each root. The canals were divided into four experimental groups (n=10 in each). The canals were then filled via cold lateral compaction (CLC) or a thermoplasticized injectable technique (TT) using gutta-percha and AH Plus root canal sealer. The roots were scanned with a micro-CT, and the volumes of the voids and gaps were calculated using three-dimensional (3D) micro-CT images. Data were analyzed using unpaired t- and Krus- kal-Wallis tests. A value of P < 0.05 was considered significant.
Results: None of the tested techniques provided void- or gap-free fillings. Nevertheless, the SAF showed more gap formation than the Revo-S, and TT showed higher gap formation in all experimental groups. These differences, however, were not statistically significant (p>0.05).
Conclusion: The SAF and Revo-S rotary file systems yielded comparable results. No statistically significant difference was found between the results of the various instrumentation and filling techniques.

Objective: The purpose of this randomised clinical trial study was to compare the incidence and intensity of post-operative pain following the use of single-file and multi-file rotary instruments with continuous rota- tional motion for root canal preparation in asymptomatic permanent human teeth.
Methods: A total of 105 healthy consenting patients who fulfilled specific inclusion criteria and had premo- lar or molar teeth diagnosed with asymptomatic irreversible pulpitis without periapical pathosis requiring endodontic treatment participated in this study. The patients were randomly allocated by stratification into five groups of 21 according to the instruments and systems used for root canal preparation: (a) Neoniti A1 (#25) single file, (b) RaCe #25/.06 single file, (c) Mtwo #25/.06 single file, (d) Easy RaCe, (e) and Mtwo multi- file. Endodontic treatment was carried out in a single appointment. The severity of post-operative pain was assessed by numerical rating scale scores until complete pain relief was achieved. Analgesic consumption and the incidence of pain were also evaluated. Data were analysed by one-way ANOVA and Tukey HSD tests. Results: When comparing different instruments and systems for canal preparation, the analgesic consump- tion, incidence and intensity of post-operative pain did not differ (p>0.05). The highest levels of post-opera- tive pain were experienced after 6 h in all groups.
Conclusion: The post-operative pain did not differ between the single and multi-file root canal preparation techniques evaluated in this study.

Objective: To evaluate the fracture resistance of different intra-radicular post systems in flared root canals.
Methods: Sixty human canines were used. The coronal portion was removed and the root length was standardized at 17 mm. Canals were prepared and filled with gutta-percha/AH Plus sealer. Roots were embedded in self-polymerising acrylic resin blocks. According to the material used, the teeth were randomly divided into three groups (n=20): glass fibre post (GFP): GFP and Z350 resin composite core; pre-fabricated metal post (PMP): PMP and Z350 resin composite core; and cast metal core (CMC): CMC with silver-tin alloy. Coronal reconstruction involved fabrication of metal copings. Samples were submitted to mechanical compression testing at 45º in a universal test machine. Fracture pattern was evaluated under a stereoscope. The fracture strength values were submitted to one-way analysis of variance (ANOVA) and Tukey tests (α=0.05).
Results: There was no statistically significant difference between the resistance values among groups (P=0.193). With regard to fracture pattern, GFP showed 55% and PMP 45% of Type I fractures, which considered repairable or favourable, whereas MCC presented 50% of Type V, which was considered irreparable or unfavourable.
Conclusion: Glass fibre and pre-fabricated metal posts have good fracture resistance to compression and may be used for restoring flared root canals, since they presented fractures mainly involving the filling core, thus facilitating later repair.

Objective: To determine the prevalence and distribution of pulp stones in the posterior teeth of a sample of adult Yemeni dental patients using digital panoramic radiographs.
Methods: In total, 913 panoramic radiographs from patients attending the hospital dental clinics of at Uni- versity of Sciences and Technology, Sana’a, Yemen, from January 2013 to December 2014 were examined. The occurrence of pulp stones in the posterior teeth of adult subjects was recorded. Associations between pulp stones and gender, age, arch, side and tooth type were studied.
Results: The overall prevalence of pulp stones was 18.6% for individuals (170 out of 913 subjects) and 3.99% for examined teeth (351 out of 8802 teeth). The pulp stone occurrence was significantly higher in the maxilla than in the mandible for each tooth type and location (P<0.001). Pulp stones occurred more often on the right side (P<0.001). First molars represented 71% of the affected teeth with the maxillary right first molar showing the highest occurrence. Fifty-six percent of the affected subjects had pulp stones in more than one tooth. No significant difference in the occurrence of pulp stones was detected between genders or among age groups (P>0.05).
Conclusion: The prevalence of pulp stones is different among populations. Pulp stones were found in approx- imately one-fifth of subjects in the Yemeni population, where up to 90% of the population have a Qat-chew- ing habit. This habit usually causes mechanical and chemical irritation and results in pulp calcification.

This case report describes the treatment of a double root fracture of a lateral mandibular incisor and its fol- low-up over 3.5 years.
The reason for the consultation was a tooth mobility following a fall that had occurred 2 days earlier. A test of pulp vitality for tooth 42 was positive. Periodontal probing at the level of the gingival sulcus confirmed the intactness of the epithelial attachment. Retro-alveolar radiographic examination revealed a double root fracture of tooth 42.
A semi-rigid extra-coronal splinting was performed and a light grinding of the incisal edge of tooth 42 was then carried out in light of the dislocation of the coronal fragment, and the occlusion was checked with a strip of articulating paper. The outcomes at 6 months revealed that pulp vitality was still preserved, consol- idation of the apical fracture had occurred, and the coronal root fracture was starting to heal. The 1-year, 2-year and 3-year follow ups revealed preserved pulp vitality, an absence of a fracture line in apical images, and no root resorption.
This case report provides evidence for the preservation of vitality in the setting of a double root fracture.

Objective: Under the Global Medical Device Nomenclature (GMDN) system, the newly introduced term ‘hy- groscopic dental cement’ (HDC) encompasses MTA as well as cements based on bioceramics, calcium silicate or calcium sulphate. Many HDCs have a long history of use in dentistry. There is a need for a consistent, logical and informed approach to the nomenclature of traditional and novel HDCs.
Methods: Commercial manufacturers of HDC were contacted requesting information on the compositions of products. Manufacturers that were unknown to the authors, that were unable to be contacted, that wished to be excluded from this paper, or that did not send their information on compositions in due time were not included.
Results: The compositions of commercial HDCs include various hybrids of calcium silicates, calcium alumi- nates, calcium phosphates, calcium sulphate as well as zinc sulphates. Furthermore, there are variations in the radiopacifier as well as additives that change the handling or setting processes.
Conclusion: The inclusion of different additives to HDCs enables variation in handling properties such that they now exist as distinct putties and sealers as well as cements.

In young patients, premature tooth loss in the anterior maxilla after trauma is challenging for the patient and the dental professional, with serious implications from aesthetic and functional points of view, as well as from a craniofacial growth aspect perspective. Premolars autotransplanted into the maxillary anterior region have been shown to be a biological alternative in this situation. This report describes the clinical management of a case of premature loss of a maxillary central incisor after traumatic injury. A mandibular premolar at the stage of initial root development was transplanted into the alveolar socket of the lost incisor. After 18 years, the transplanted tooth remained responsive to pulp sensibility tests and the periradicular bone and soft tis- sues were within normal limits. Autotransplantation of premolar teeth into the maxilla could be considered an excellent treatment choice with many biological advantages over implants or fixed dentures as long as proper case selection is followed.

Objective: Antimicrobial photodynamic therapy (aPDT) is a controversial approach for endodontic disinfection. The objective of this study was to test the photosensitiser (PS) concentration and assess the optical shielding phenomenon, the use of hydrogen peroxide (H2O2) and minimal energy irradiation to optimise endodontic aPDT for suggesting a protocol for clinical use.
Methods: Different parameters for aPDT were tested. Aqueous solutions of methylene blue (MB) at 50, 100, 150 and 300 μM were tested in vitro for optical shield and reactive oxygen species (ROS) production by the reduction of N,N-dimethyl-4-notrosoaniline (RNO) at 440 nm absorbance when irradiated using a diode laser (660 nm). Ten single-rooted teeth were inoculated with bioluminescent bacteria Pseudomonas aeruginosa for 72 hours to form biofilms. Bioluminescence imaging was used to serially evaluate the minimum energy necessary during endodontic aPDT using MB and a diode laser coupled to an optical fibre for intracanal microbial reduction. In addition, teeth (n=21) infected with Enterococcus faecalis were treated with sequential combinations of endodontic aPDT and H2O2 and the colony-forming unit (CFU) was determined.
Results: ROS production was inversely proportional to the MB concentration in the solution due to quenching of MB. Optical shielding limited light penetration at high MB concentrations. The use of H2O2 before aPDT achieved higher disinfection compared to conventional aPDT or when MB was irradiated in an H2O2 solution. Energy irradiation of 9.6 J achieved a significant reduction and further light delivery did not produce further reduction.
Conclusion: PS concentration of about 50 μM, biofilm pre-treatment with H2O2 for 1 min and energy irradiation around 10 J appear to be an effective protocol for endodontic aPDT.

Objective: To investigate the influence of calcium hydroxide (Ca(OH)2) on susceptibility to disinfection with sodium hypochlorite (NaOCl) of biofilm bacteria.
Methods: Monospecies biofilms of eight Enterococcus faecalis strains were subjected to a 2-h challenge with Ca(OH)2. After a recovery phase, the biofilms were treated with a concentration of NaOCl that was lower than the minimum inhibitory concentration. In a metabolic assay, the efficacy of NaOCl disinfection in Ca(OH)2-challenged biofilms and unchallenged biofilms was evaluated. The data were analyzed with Mann-Whitney U and Kruskall- Wallis tests. A P value of less than 0.05 was considered statistically significant.
Results: There were marginal differences in susceptibility to NaOCl among the E. faecalis strains. After the Ca(OH)2 challenge, seven strains remained equally susceptible to NaOCl disinfection whereas one strain be- came more resistant to NaOCl (P= 0.03).
Conclusion: After a Ca(OH)2 challenge, in general E. faecalis remained equally susceptible to disinfection with NaOCl.

Objective: The purpose of this article was to report the finding of the disappearance of intracanal medica- tion as a supporting evidence of vertical root fracture (VRF) through non-surgical intervention.
Methods: A retrospective review of the dental records of patients seen by an endodontist in a private end- odontic office from September 2013 to September 2016 was conducted by the same endodontist. Cases that met the inclusion and exclusion criteria were assigned as the subjects of this study, and data were ex- tracted from their clinical and radiographic records. Patient’s demographic features, pre-operative signs and symptoms, details of rendered clinical procedures, follow-up visits, clinical and radiographic findings were recorded. Seventeen teeth for which non-surgical exploratory re-treatment was initiated were included in this study. Calcium hydroxide-based intracanal medication was placed for 2-4 weeks. Obturation of the root canals was performed if the tooth showed improvement of clinical signs and symptoms. If not, a cone-beam computed tomography (CBCT) scan was proposed to the patient to rule out VRF.
Results: After the non-surgical re-treatment was initiated, 13 teeth showed improvement of clinical symp- toms and the re-treatment was therefore completed. The remaining 4 teeth presented with unresolved clin- ical presentations (deep pocket, presence of sinus tract and/or tender to percussion and palpation). Four teeth showed partial disappearance of intracanal medication where VRF was confirmed using CBCT in 3 teeth and with a conventional periapical (PA) radiograph in 1 tooth.
Conclusion: The disappearance of intracanal medication during non-surgical intervention was often associ- ated with VRF. Thus, this feature may serve as an aid in diagnosing VRF.

Objective: The aim of this study was to compare the cyclic fatigue resistance of Reciproc (VDW, Munich, Germany) and Reciproc Blue (VDW) in artificial canals with both single and double (s-shaped) curvatures.
Methods: In total, 80 instruments were tested in this study. Reciproc R40 and Reciproc Blue R40 instruments were selected for the cyclic fatigue resistance test (n=20 in each test). Each instrument was rotated in canals with a single curvature (60° curvature, 5-mm radius) and a double curvature (first coronal curve: 60° curvature and 5-mm radius; second apical curve: 70° and 2-mm radius) until fracture. The time to fracture was calculated, and the length of each fractured fragment was recorded. A one-way analysis of variance (ANOVA) and Tukey’s post hoc tests were used to analyse the time to failure.
Results: All the instruments had significantly higher fatigue resistance in the single simulated curvature canal than in the double curvature canal (P<0.05). In both curvature groups, the time to fracture of the Reciproc Blue was longer than that of the Reciproc instruments (P<0.05). In the double curvature canal, the instruments tended to fracture more often in the apical curvature than in the coronal curvature. There was no significant difference in the length of the broken fragments between the two groups in either the single or double canal curvatures (P>0.05).
Conclusion: The Reciproc Blue instruments showed higher cyclic fatigue resistance than the Reciproc instruments in both single and double canal curvatures.