Effectiveness of MTA apical plug in dens evaginatus with open apices

Background The present study aims to evaluate the effectiveness of mineral trioxide aggregate (MTA) application in treating dens evaginatus affected teeth with apical lesions and open apices using haemostatic collagen membrane to prevent the apical extrusion of MTA. Methods Twelve patients with 14 dens evaginatus affected teeth with apical lesions and open apices were treated with MTA apical plug and haemostatic collagen membrane. Clinical symptoms of subjective pain, pain of palpation, percussion, sinus tract, and the apical lesions' radiographic parameter were recorded at every 3-month interval up to 9 months after treatment. Paired t-test or Wilcoxon signed-rank test was used for statistical analysis with P < 0.05 as the threshold for considering results to be statistically significant. Results No patient experienced clinical symptoms 3 months after endodontic treatment. In addition, there was a significant difference in the dimensions of the apical lesions' before compared to 3 months after endodontic treatment. Conclusions The combination of MTA apical plug and haemostatic collagen membrane effectively treated dens evaginatus affected teeth with apical lesions, and open apices.

Apical Extrusion of Debris during Root Canal Preparation with ProTaper Next, WaveOne Gold and Twisted Files

(1) Background: Apical extrusion of debris is an example of a complication that may arise during root canal treatment, and it has been proven to be an unavoidable occurrence during endodontic treatment by numerous authors. Even though it may not hinder the long-term outcome of treatment, it may lead directly to increased levels of postoperative pain and, therefore, lower levels of patient acceptance and satisfaction. The aim of the study was to assess the weight of apically extruded debris during root canal preparation with instruments that use different movement kinematics (rotary, reciprocating, and adaptive motion); (2) Methods: The study was performed using the Myers and Montgomery model. Sixty human premolar teeth were inserted into preweighed Eppendorf tubes and randomly classified into three groups. After manual glide-path preparation, teeth in each group were instrumented to working length set 1 mm short of the anatomical apex using the standard sequence provided by the manufacturers (for Group 1: ProTaper Next X1 & X2; for Group 2: WaveOne Gold Primary, for Group 3: Twisted Files SM1-SM3). Root canals were irrigated with 1 mL of 0.9% NaCl solution between each file insertion. The tubes with collected debris were stored in an incubator at 70 °C for 5 days in order to evaporate the liquid component. Measurement of the weight of extruded debris was performed by subtracting the preinstrumentation from the postinstrumentation weight of the tubes. The results were analyzed with Kruskal–Wallis ANOVA, with significance level set at 0.05; (3) Results: The weight of extruded debris was 0.337 mg (SD = 0.148) for Group 1, 0.305 mg (SD = 0.201) for Group 2, and 0.348 mg (SD = 0.135) for Group 3. (4) Conclusions: Engine-driven root canal preparation with the use of instruments ProTaper Next, WaveOne Gold and Twisted Files that use different movement kinematics (rotary, reciprocating, and adaptive motion) was associated with apical extrusion of debris to a similar extent.

Comparing the effect of Reciproc R25 rotary file system on the amount of apical extrusion of debris via using it with different reciprocal angles

Aim: To compare the amount of apically extruded debris using Reciproc (R25) file with different reciprocal angles. Methodology: In this research, 60 extracted mandibular premolars with a single root, a single canal, and a single apical foramen were used. Specimens, the working length of which was determined by a stainless steel 10-K file, were randomly distributed into three experimental groups (n = 20) as follows: Group 1 150° counterclockwise (CCW)-30° clockwise (CW); Group 2 180° CCW-60° CW; and Group 3 210° CCW-90° CW. For the irrigation, 10 mL of distilled water was administered via syringe pump. The extruded debris was collected into Eppendorf tubes tared in advance. The distribution of data was analyzed using a Shapiro-Wilk test. A Kruskal-Wallis H test was used for statistical analysis. The null hypothesis is no significant difference between the groups in terms of the amount of apical extrusion of debris. Results: There was no statistically significant difference between the groups with regard to amount of apical extrusion of debris (p>0.05). Nevertheless, the highest average amount of extrusion of debris was detected in group 1, and the lowest in group 3. Conclusion: According to the results of this study, different reciprocal angles during chemomechanical preparation has no significant effect on the amount of apical extrusion of debris. How to cite this article: Çelik N, Kaya S, Adıgüzel Ö. Comparing the effect of Reciproc R25 rotary file system on the amount of apical extrusion of debris via using it with different reciprocal angles. Int Dent Res 2021;11(Suppl.1):63-6. https://doi.org/10.5577/intdentres.2021.vol11.suppl1.10 Linguistic Revision: The English in this manuscript has been checked by at least two professional editors, both native speakers of English.

A Ca2+ wave generates a force during cell extrusion in zebrafish

When oncogenic transformed or damaged cells appear within an epithelial sheet, they are apically extruded by surrounding cells. Recently, using cultured mammalian epithelial cells and zebrafish embryonic epithelial cells, we found that a calcium (Ca2+) wave propagates from RasV12-transformed cells and laser-irradiated damaged cells to surrounding cells and promotes apical extrusion by inducing polarized movements of the surrounding cells. In mammalian cell cultures, we reported that the inositol trisphosphate (IP3) receptor, gap junctions, and the mechanosensitive Ca2+ channel TRPC1 are involved in Ca2+ wave-mediated polarized movements. However, which molecules regulate Ca2+ wave-mediated polarized movements in zebrafish and whether the Ca2+ wave can generate a force remain unknown. In this study, we aimed to answer these questions. By performing pharmacological and gene knockout experiments, we showed that a Ca2+ wave induced by the IP3 receptor and trpc1 led to formation of cryptic-lamellipodia and polarized movements of surrounding cells toward extruding cells in zebrafish. By using an in vivo force measurement method, we found that the Ca2+ wave generated approximately 1 kPa of force toward extruding cells. Our results reveal a previously unidentified molecular mechanism underlying the Ca2+ wave in zebrafish and demonstrate that the Ca2+ wave generates a force during cell extrusion.

What’s new for the clinician? Excerpts from and summaries of recently published papers

Pulpectomy is a conservative treatment approach for preventing the premature loss of primary teeth that can result in loss of arch length, insufficient space for erupting permanent teeth, impaction of premolars, and mesial tipping of molar teeth adjacent to the lost primary molar. Pulpectomy is a procedure which involves removal of the roof of pulp chamber in order to gain access to the root canals which are debrided, shaped, disinfected, and obturated later with a resorbable material. As a result, the tooth can be maintained in the arch without vital pulp tissue, without compromising the function of the tooth. The most common complications associated with pulpectomy, post-operative pain (PP) and/or swelling, commence after treatment. These are always unpleasant experiences for both patients and clinicians. The apical extrusion of infected debris or irrigation solution during the canal preparation or irrigation procedure may worsen the inflammatory response and cause periradicular inflammation and postoperative pain. It is well-documented that the type of irrigation method affects the amount of apically extruded debris (AED) in permanent teeth. No study has evaluated the effect of different needle types on the intensity and duration of PP after pulpectomy in primary molars. Topçuoglu and colleagues reported on a trial that sought to compare the intensity and duration of postoperative pain after pulpectomy using open-ended needles (OEN) versus sidevented needles (SVNs) in primary upper molars.

Influence of different reciprocating systems on the apical extrusion of debris in flat-oval canals

Aim: To evaluate the apical extrusion of debris in flat-oval canals, using three reciprocating systems at two different working lengths (WL), 0 mm and 1 mm from the apical foramen. Methods: Ninety mandibular incisors were randomly divided into three groups based on the systems: WaveOne Gold #25.07 (WOG), ProDesign R #25.06 (PDR), and X1 Blue #25.06 (X1B). Extruded debris were collected and dried in pre-weighed Eppendorf tubes. Three consecutive weighings were performed for each tube, and the mean was calculated. If the assumptions of normality and homogeneity of variance were not met, the Kruskal-Wallis test was used to analyze the amount of extruded debris between groups with the same WL, and the Mann-Whitney U test was used for comparison within groups for each WL. Results: All groups had extruded debris, with higher median values occurring at 1 mm. No significant difference regarding the amount of debris extrusion was observed at 0 mm (p>0.05) and 1 mm (p>0.05) between groups. However, within the groups, at different WL, there was greater extrusion at 1 mm (p<0.05), with PDR differing significantly from the other systems (p<0.05). Conclusion: The extrusion of debris occurred regardless of the group, with higher values at 1 mm. However, using PDR at 1 mm from the apical foramen showed the highest values of extrusion.