Morphological changes of the apical foramen after enlargement: A scoping review of in vitro studies.

Background: To outline the current evidence on root morphological changes after enlarging the apical foramen with NiTi instruments. Material and Methods: A search was performed in the Virtual Health Library, PubMed, EMBASE, Scopus, Web of Science, Science Direct and SciELO databases, in addition to a manual search in Google Scholar, between January 2017 and October 2023. Articles published in English that describe in vitro studies investigating root morphological changes after instrumentation 1 mm beyond the major apical foramen were included. The quality of evidence in the included studies was also analyzed. Results: The search retrieved 367 articles. Of these, four studies were eligible for data synthesis and analysis, all of them in vitro studies. Synthesis of the results of these in vitro studies showed a larger number of root morphological changes such as experimental dentinal microcraks in samples submitted to instrumentation beyond the apical foramen when compared to micro-CT images obtained before preparation. Conclusions: The in vitro studies analyzed in this scoping review indicate that instrumentation beyond the major foramen of the root canal, promotes morphological changes in this area and that the adoption of standardized methodologies would not only increase the accurate detection and characterization of these changes but also facilitate the application of these findings in clinical trials and patient care. Key words:Endodontics, apical morphology, root canal preparation.

Morphological Study of Root Canals of Maxillary Molars by Cone-Beam Computed Tomography.

The aim of this study was to evaluate the root canal morphology of permanent maxillary molars by cone-beam computed tomography (CBCT) using the classifications of Weine et al. and Vertucci and to correlate the findings with sex, age, position in the dental arch, and prevalence of a second canal in the mesiobuccal root (MB2). A total of 414 scans were evaluated, corresponding to 1,000 teeth. The assessment consisted of coronal, axial, and sagittal reconstructions using i-CAT Workstation®. Type 0 was assigned when neither classification could be applied. The data were entered into an Excel spreadsheet and analyzed using SPSS. The chi-squared test or Fisher's exact test was used to compare the distribution of root canal morphology classified using the two systems. Analysis of the distribution of Weine types showed a predominance of type III in mesiobuccal roots, while type 0 predominated in distobuccal and palatal roots. Vertucci type IV predominated in mesiobuccal and distobuccal roots and type VII in palatal roots. There was no difference in the distribution of morphological canal types in permanent maxillary molars evaluated by CBCT according to sex, age group, or position in the dental arch of the patients. MB2 canals were identified in 68.4% of the teeth evaluated.

Scope of Preparation of Oval and Long-Oval Root Canals: A Review of the Literature.

Successful endodontic treatment depends on cleaning and disinfecting the root canals, in order to provide conditions for three-dimensional filling, which should prevent root canal reinfection. However, anatomical complexities pose a challenge during endodontic treatment. The present study was a literature review carried out in the following databases: PubMed, SciELO, and MEDLINE, which were searched for articles published from 2017 to 2021. Micro-CT studies published in English, which analysed the capacity for preparation of oval and long-oval root canals, were included. The following keywords were used: "oval-shaped canals," "long-oval-shaped canals," "endodontics," and "micro-CT." The aim of this study was to carry out a literature review of micro-CT studies on the scope of the capacity for preparation performed in oval and long-oval root canals with rotary and reciprocating instruments.

Cyclic Fatigue Resistance of Blue Heat-Treated Instruments at Different Temperatures.

The main aim is to evaluate the cyclic fatigue resistance of blue heat-treated instruments with different kinematics. Twenty-four endodontic instruments of the same brand were used for each of three experimental groups: VB (Vortex Blue 40/0.04), RB (RECIPROC Blue 40/0.06), and XB (X1 Blue 40/0.06). The instruments were randomly distributed and subjected to temperatures of 20°C and 37°C. The fatigue test was performed using a stainless steel device. Data were analysed using the Shapiro-Wilk test, Student's t-test, the F test, and Tukey's and Tamhane tests at significance level P=0.05. The instruments' cyclic fatigue resistance at both temperatures differed significantly for each instrument type (P < 0.001). The RB instruments displayed greater cyclic fatigue resistance at the tested temperatures compared with the VB and XB instruments (P < 0.001). Reciprocating kinematics positively influenced cyclic fatigue resistance. Blue heat-treated instruments showed decreased cyclic fatigue resistance as the temperature increased (P < 0.001).

Tooth autotransplantation using an interdisciplinary approach to rehabilitation in a young patient: Case report with 7-year follow-up.

This case report demonstrates the possibility of functional and aesthetic rehabilitation using an interdisciplinary approach in a child following avulsion of a tooth. Autotransplantation after the development of calcific metamorphosis of the pulp and acute apical periodontitis provided satisfactory repair after root canal treatment. A 7-year-old white boy avulsed the right maxillary central incisor (tooth 11). The extra-alveolar time exceeded 60 minutes, and this triggered external replacement resorption of the avulsed tooth. At 11 years of age, the child underwent tooth autotransplantation. After 4 years of follow-up, intraoral clinical and radiographic examination led to the diagnosis of calcific metamorphosis of the pulp and acute apical periodontitis. The patient had minimally invasive root canal treatment, orthodontic treatment and esthetic rehabilitation with a porcelain crown. Control periapical radiography and tomography of the autotransplanted tooth after 7 years revealed bone repair in the periapical region. This case report indicates that tooth autotransplantation can be used to replace anterior teeth after avulsion followed by replacement resorption. Interdisciplinary management helped to maintain the esthetics and function of the rehabilitated area.

Reciproc and Reciproc Blue in the removal of bioceramic and resin-based sealers in retreatment procedures.

OBJECTIVES: To compare the remaining root canal filling material, dentin removal, apical transportation, and apical extrusion of debris after the retreatment of canals filled with bioceramic or resin-based sealers using the Reciproc or Reciproc Blue instruments. MATERIALS AND METHODS: Sixty mandibular molars with severely curved mesial roots were selected. The samples were initially instrumented with Reciproc (R25) and then divided into four experimental groups according to the endodontic sealer and retreatment instrument (n = 15): BC Sealer/Reciproc (BCRC), BC Sealer/Reciproc Blue (BCRB), AH Plus/Reciproc (AHRC), and AH Plus/Reciproc Blue (AHRB). The procedure time was measured, and an Eppendorf tube was used in each root canal to store the debris extrusion. The samples were scanned by micro-CT before and after retreatment. The apical transportation, volume of dentin, and filling material were evaluated. RESULTS: There were no significant differences in the reduction of the volume of obturator material or dentin removal between groups (p > .05). There were also no differences in the amount of extruded material or apical transportation (p > .05). The retreatment time for the AHRC group was significantly lower than that for the other groups (p = .004). CONCLUSIONS: All tested instruments obtained similar efficacy in filling material removal procedures, although no system completely removed the filling material. Retreatment of canals filled with bioceramic BC Sealer may be more time consuming. CLINICAL RELEVANCE: This study reported that Reciproc and Reciproc Blue can be indicated in retreatment of severely curved root canals filled either with bioceramic or resin-based sealers.

Microcomputed Tomography Studies of the Effectiveness of XP-endo Shaper in Root Canal Preparation: A Review of the Literature.

The aim of this study was to undertake a literature review on the use of XP-endo Shaper (FKG Dentaire SA, La Chaux-de-Fonds, Switzerland) for root canal preparation evaluated using microcomputed tomography (micro-CT) technology, with emphasis on the analysis of untouched canal walls. We searched the PubMed, Science Direct, SciELO, and MEDLINE databases for articles published from 2017 to 2019 using the following keywords: micro-CT, untouched walls, XP shaper, and XP endo. Articles without an abstract were excluded. Five papers were selected. Few studies on this topic are available. The studies published so far show that the XP-endo® Shaper system performs well in terms of canal preparation but leaves untouched walls.

Antibacterial Activity of Rosmarinus officinalis, Zingiber officinale, Citrus aurantium bergamia, and Copaifera officinalis Alone and in Combination with Calcium Hydroxide against Enterococcus faecalis.

This study aimed to evaluate the efficacy of different concentrations of essential oils combined with calcium hydroxide against Enterococcus faecalis. Thirteen experimental groups were formed: NC (negative control); PC (positive control); GC (growth control); SC (sterilization control); RO (Rosmarinus officinalis); ROH (calcium hydroxide + RO); ZO (Zingiber officinale); ZOH (calcium hydroxide + ZO); AB (Citrus aurantium bergamia); ABH (calcium hydroxide + AB); CO (Copaifera officinalis); COH (calcium hydroxide + CO); DWH (calcium hydroxide and distilled water). After reconstitution of the E. faecalis strain, microdilution testing was performed to define the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). The data were tabulated in an Excel spreadsheet, and the MIC and MBC were calculated in accordance with the Bacteriological Analytical Handbook. MICs in the range of 0 to 100 mg/ml were only observed in the ROH group. The RO, ROH, AB, ZO, and ZOH presented absolute data for MBC. Bacterial growth was detected in the DWH group at all concentrations tested. The combination of the essential oils tested here with calcium hydroxide appears promising as an intracanal medication in endodontic treatment because of its effectiveness against Enterococcus faecalis. Essential oils are important in endodontic therapy since calcium hydroxide, the gold standard intracanal medication, is not effective against E. faecalis.