Objective: Irrigant activation has been claimed to be beneficial in in vitro and clinical studies. This systematic review aims to investigate the clinical efficiency of mechanically activated irrigants and conventional irrigation.
Methods: A literature search (PROSPERO registration number: CRD42018112595) was undertaken in PubMed, Cochrane and hand search. The inclusion criteria were clinical trials, in vivo/ex vivo on adult permanent teeth involving an active irrigation device and a control group of conventional irrigation. The exclusion criteria were studies done in vitro, animals and foreign language. Adult patients requiring endodontic treatment of permanent dentition and irrigant activation during the treatment were chosen as the participants and intervention respectively.
Results: After removal of duplicates, 89 articles were obtained, and 72 were excluded as they did not meet the selection criteria. 6 devices (EndoVac, EndoActivator, Ultrasonic, MDA (manual dynamic agitation), CUI (Continuous Ultrasonic Irrigation) and PUI (Passive Ultrasonic Irrigation)) and 6 variables of interest (Post-operative pain, periapical healing, antibacterial efficacy, canal and/or isthmus cleanliness, debridement efficacy and delivery up to working length) were evaluated in the 17 included articles. The risk of bias and quality of the selected articles were moderate. Results showed that mechanical active irrigation reduces post-operative pain. It improved debridement, canal/isthmus cleanliness. It also improved delivery of irrigant up to working length. Bacterial count was more with active irrigation, though not significant. There is no effect on long-term periapical healing.
Conclusion: It may be concluded that mechanical active irrigation devices are beneficial in reducing post-operative pain and improving canal and isthmus cleanliness during Endodontics.

Ever since their introduction, nickel–titanium (NiTi) alloys have continued to revolutionize the field of endodontics. They have considerable advantages over the conventional stainless steel file in terms of mechanical properties. However, despite of their superior mechanical properties, NiTi alloys still pose some risk of fracture. Consequently, there has been considerable research conducted to investigate the mechanisms behind the occurrence of these procedural errors. Since the last decade, different proprietary processing procedures have been introduced to further improve the mechanical properties of NiTi alloys. These treatments include thermal, mechanical, electropolishing, and recently introduced electric discharge machining. The main purpose of these treatments is to impart a more martensitic phase into the files at normal body temperature, so that the maximum advantage of flexibility can be obtained. These heat-treated instruments also possess improved cyclic fatigue resistance when compared to conventional NiTi alloys. NiTi alloys can be subclassified as the instruments mainly containing austenitic phase (conventional NiTi, M-wire, R-phase), and those containing martensitic phase (controlled memory wire, ProTaper Gold, and Vortex Blue). Instruments based on austenitic alloys possess superelastic properties due to the stress-induced martensitic transformation. Contrary to this, martensitic alloys can easily be deformed due to phase transformation, and they can demonstrate the shape memory effect when heated. This review discusses the different phase transformations and heat treatments that the NiTi instruments undergo.

Objective: To compare the efficacy of platelet-rich fibrin (PRF) and Hank’s balanced salt solution (HBSS) in the preservation of the periodontal ligament (PDL) cells viability of avulsed teeth.
Methods: A total of 30 non-carious third molars with healthy periodontium, indicated for extraction for orthodontic reasons or chronic pericoronitis, were selected for the study. Samples were divided into four groups: one standard group and one experimental group in addition to two control groups (positive and negative). The positive and negative control group corresponded to immediate and 2-hour dry time respectively. The experimental teeth were bench dried for 40 minutes and then immersed in one of the two storage media: HBSS (standard storage media) and PRF (experimental storage media) for 45 minutes. The teeth in each group were treated with dispase II and collagenase for 30 minutes and later centrifuged for 4 minutes at 1000 rpm. The supernatant was removed with sterile micropipette, the cells were labeled with 0.4% trypan blue, and the number of viable PDL cells was counted with a hemocytometer under a light microscope. One-way Kruskal–Wallis test and Mann–Whitney U test with Boneferroni correction were used for statistical analysis.
Results: Results did not demonstrate any statistically significant differences in the viability of PDL cells between the groups with standard and experimental storage media. Group 1 showed a statistically significant difference of mean compared to Groups 2, 3 and 4. When Group 2 was compared with Groups 3 and 4, a P-value>0.05 suggested no statistical significance.
Conclusion: Within the parameters of this study, HBSS and PRF demonstrated a similar number of viable PDL cells. Hence, PRF could be a used as a good substitute of HBSS as a storage media for avulsed teeth.

Objective: The objective of the present study was to evaluate the influence of different irrigation solutions on the amount of extruded residues apically, varying the instrumentation technique in manual, continuous rotation, or reciprocation motions. The amounts of residue for each irrigation solution was also assessed.
Methods: Two tests were performed. In the first test, 90 mandibular premolars were divided into nine groups (n=10). Each group was subjected to a different technique: ProTaper Universal, WaveOne Gold, or manual instruments, with different irrigation solutions [2.5% sodium hypochlorite (NaOCl), 2% chlorhexidine (CHX) gel, or distilled water]. During the preparation of the root canal, the apically extruded material was collected in previously weighed glass vials. In the second test, irrigation solutions were weighed separately with the same weighing method. Data were analyzed using the Kolmogorov–Smirnov, one-way and two-way ANOVA, Levene, Tukey, and Games–Howell tests.
Results: Apically extruded debris was observed in all groups. ProTaper Universal with continuous rotation using 2% CHX gel resulted in the greatest amount of debris (P<0.001). There were significant differences in the amounts of residue among the different groups (P<0.001). Moreover, when the weighing of the irrigation solutions was tested, the 2.5% NaOCl solution produced the greatest amount of residues compared with other irrigation solutions.
Conclusion: Different irrigation solutions influenced the amount of apically extruded debris during the preparation of the canal among the different instrumentation techniques. The ProTaper technique using 2% CHX gel resulted in the greatest amount of apically extruded debris.

Objective: To compare the effects of different irrigation protocols, with/without laser activation, on the radicular dentine’s micro-hardness.
Methods: Eighty-two human extracted premolars were decoronated and divided into 7 groups. Roots were longitudinally split into two halves. The micro-hardness was measured for one half before and after irrigation protocols. The groups were; G1: MTAD without laser-activation, G2: MTAD with laser-activation, G3: sodium-hypochlorite (SH) with laser-activation, G4: SH then EDTA with laser-activation, G5: SH then MTAD with laser-activation, G6: SH without laser-activation. G7: distilled water (control). In the two-irrigants groups G4 and G5), samples were irrigated first with SH then with MTAD or EDTA irrigants, which were activated by the laser. The difference between the before- and after-irrigation micro-hardness was calculated to obtain the micro-hardness difference. Data were analyzed using the Paired Sample-t and Two-ways ANOVA tests at P=0.05.
Results: Overall, the mean dentine’s micro-hardness after-irrigation (103.1) was lower than before-irrigation (116.1) (P<0.001); except for the distilled-water group, (116.6 and 112.9, respectively) (P=0.075). The micro-hardness reduction of SH without laser-activation group (32.5) was the greatest (P<0.001). The single-irrigant or laser-activation irrigation protocols caused significantly less micro-hardness reduction compared to the two-irrigants or no laser-activation protocols. The mean micro-hardness reduction of SH and MTAD groups (both with laser-activation) (5.8 and 9.3, respectively) were significantly lower than other groups, but not from that of the control group (3.7).
Conclusion: Using irrigants significantly reduced the root-dentine’s micro-hardness. Although irrigants agitation by an Er: Yag laser significantly minimized micro-hardness reduction, it did not suppress the adverse effects on dentine micro-hardness when two-irrigants were used.

Objective: To assess the detection of simulated periapical lesions in digital intraoral radiography with different levels of brightness and contrast combinations, and to investigate the observers’ preference of image quality for this diagnostic task.
Methods: Digital radiographs were acquired prior to periapical lesion simulation and after each one of four defects enlargement. Original images were adjusted in 4 brightness and contrast combinations. Five observers evaluated the images according to the presence of periapical lesion on a 5-point scale. In a second moment, the observers ordinated the images subjectively, according to quality, from the best to the worst to detect the bone defect. The area under the receiver operating characteristic curve was calculated for the diagnostic values and compared by two-way ANOVA. The significance level was set at 5% (P<0.05).
Results: No differences were found between the diagnostic values of the five combinations of brightness and contrast (P>0.05). The overall results showed low values of area under the Receiver Operating Characteristic (ROC) curve and sensitivity of the periapical radiography in the detection of periapical lesions of sizes from 1 to 3, which rose substantially in size 4. For image quality, combinations with the lowest brightness and highest contrast were preferred by the observers in 58% of the cases.
Conclusion: Brightness and contrast adjustments do not influence the detection of simulated periapical lesions in digital intraoral radiography. Lower brightness and higher contrast images were preferred for this diagnostic task.

Objective: Maintaining the remaining dentine thickness (RDT) is crucial because it acts as a protection barrier to the vital pulp tissue against injury and inflammatory products. Based on the relationship between the radiographic RDT (RRDT) and actual RDT (ARDT), we aimed to develop a validated method for guiding dentists in estimating the RDT before caries excavation.
Methods: 30 extracted human teeth were subject to the two-stage experimentation of exposure to cone beam radiography and measurement of actual remaining dentine after sectioning. RRDT and ARDT were recorded, and the difference was statistically analyzed.
Results: A significant difference in the mean values of the estimated difference in dentine thickness was observed (P<0.05). There was no significant difference between molars and premolars as they exhibited a similar range in the difference of the RDT.
Conclusion: It is challenging to find a stable relationship between RRDT and ARDT.

A 27-year-old male patient complained of dental pain on previously root-treated tooth #17. Intentional replantation (IR) was performed. However, the symptoms returned at 10 months of follow-up, and a sinus tract was detected on the buccal gingiva of tooth #17. The patient refused extraction of the tooth and tooth was scheduled for non-surgical retreatment. Root canal retreatment was initiated with the removal of the previous root filling material while leaving the retrograde filling in situ. After 1 month of intracanal medication, the tooth became asymptomatic with complete healing of the sinus tract and the root canal filling was completed. Clinical and radiographic examination at 1 year follow-up revealed endodontic success with complete resolution of periapical radiolucency. This case report shows that non-surgical retreatment could be a viable alternative for failed IR.