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    Age-related changes in the morphology of the root canal system of mandibular first molars: A micro-CT study
    (Springer, 2023) Alak, Sabiha Gülçin; Keleş, Ali; Keskin, Cangül; Martins, Jorge N. R.; Versiani, Marco Aurelio
    ObjectiveThis study aimed to evaluate changes on root canal morphology in patients with different ages using micro-CT technology.Materials and methodsMandibular first molars (n = 150) were scanned at a pixel size of 13.68 mu m, categorized into 3 groups according to patient's age and analyzed regarding configuration, orifices, apical foramina, root length, canal volume, and surface area. Morphological 2D and 3D parameters were evaluated in distal roots with Type I configuration (n = 109) as well as the morphology of isthmuses Types I and III in 68 mesial roots. One-way ANOVA post hoc Tukey and Kruskal-Wallis tests were used for statistical analyses (alpha = 5%).ResultsA great variation in the canal configuration was found. No difference was observed in roots' length (p > 0.05). Canal volume reduced with age (p < 0.05), while surface area increased (p < 0.05) in patients <= 30 years. There was no difference in canal/root length, area, and from foramen to the apex in distal roots with Type I configuration (p > 0.05), but 2D and 3D parameters significantly decreased with age (p < 0.05). Overall, the diameter of the isthmuses' roof reduced with age (p < 0.05). In patients >= 31 years with Type III isthmus the distance from the isthmus floor to the foramen of the mesiolingual canal also decreased (p < 0.05).ConclusionOverall, the internal morphology of the mesial roots of mandibular first molars was more affected by aging than distal canals. The most relevant tested parameter that significantly reduced in both roots was the volume of the root canal systems.
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    Comparative analysis of three different filling techniques and the effects of experimental internal resorptive cavities on apical microleakage
    (2014) Keleş, Ali; Ahmetoğlu, Fuat; Ocak, Mevlüt Sinan; Dayı, Burak; Bozkurt, Alperen; Oruçoğlu, Hasan
    Objectives: The aim of this study was to evaluate the sealing abilities of three different gutta-percha techniques in experimentally defective roots (EDR) and non-defective roots (NR). Materials and Methods: Sixty canine teeth were divided into six groups of ten; Group 1, NR + cold lateral condensation (CLC); Group 2, EDR + LC; Group 3, NR + BeeFill; Group 4, EDR + BeeFill; Group 5, NR + Thermafil; and Group 6, EDR + Thermafil. Apical leakage was measured using a computerized fluid filtration meter with a laser system. Results: Statistical analysis revealed that the CLC demonstrated more microleakage in the EDR than in the NR (P < 0.01). Thermafil demonstrated more microleakage in the NR than in the EDR (P < 0.01). No statistically significant differences were found between the BeeFill groups (P > 0.05). Conclusions: The results of this study indicate that internal resorptive cavities can affect the apical sealing properties of different root canal filling techniques, with Thermafil ensuring the lowest apical microleakage. © 2014 Dental Investigations Society.
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    Identification and characterization of a previously undiscovered anatomical structure in maxillary second molars: The palato-mesiobuccal canal
    (Elsevier Science Inc., 2023) Versiani, Marco A.; Taşdemir, Tamer; Keleş, Ali
    Introduction: This report aims to communicate the discovery of a novel anatomy in a 3-rooted maxillary second molar, named as palato-mesiobuccal canal. Methods: The tooth selected for this report was found incidentally as a result of a study on extracted maxillary molars that was being conducted for an unrelated purpose and involved hundreds of teeth. This 3-rooted maxillary second molar was scanned using a micro-computed tomography device set at a pixel size of 13.68 mm. The images were reconstructed with previously tested parameters resulting in the acquisition of 1655 axial cross-sections. Three-dimensional (3D) models of the internal and external anatomies were generated in Standard Tessellation Language (STL) format and were texturized to simulate the pulp tissue. The inner structure of the tooth was analyzed through the axial cross sections and the 3D volume was qualitatively evaluated. Results: The analysis of the 3D models revealed that the maxillary second molar under examination has 3 independent roots and 4 root canals. Each root (mesiobuccal, distobuccal, and palatal) contains 1 canal, while the fourth canal follows a unique path, originating in the coronal third of the palatal canal and proceeding in a buccal direction ultimately exiting through an independent foramen at the apex of the mesiobuccal root, near the mesiobuccal canal. Conclusions: This brief communication reports the discovery of a novel anatomy in a 3-rooted maxillary second molar, named as palato-mesiobuccal canal, and provides important insights into the complexity of the root canal system in this group of teeth. (J Endod 2023;49:730-734.)
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    Micro-CT Evaluation of the Remaining Endosequence BC Filling Materials and Dentinal Microcracks after Retreatment with D-Race and R-Endo Systems
    (2024) Zincir, Şenay Gül; Kamali, Selin Göker; Türkaydin, Dilek; Keleş, Ali
    Objective: To analyze the remaining EndoSequence BC filling materials and microcrack using micro-computed tomography after retreatment with D-Race and R-Endo systems. Methods: The canals of thirty mandibular single-rooted and single-canal premolar teeth were shaped and obturated with EndoSequence BC point and EndoSequence BC sealer. The samples were assigned into two groups and scanned with micro-computed tomography. Then, the canal filling materials were removed with D-Race and R-Endo systems. After all roots were re-scanned, all images were evaluated for the remaining EndoSequence BC filling materials and microcrack. Also, retreatment time was recorded. Results: The remaining filling material in the R-Endo group was greater than the D-Race group. Both systems caused new cracks formation. However, no significant difference was noticed among them. The D-Race group needed significantly less time in comparison to the R-Endo group. Conclusion: D-Race system was faster and more efficient compared with R-Endo system. D-Race and R-Endo files caused new cracks on the canal walls.
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    A proposal to develop a new classification for pulp chamber anatomy
    (Kare Publ, 2024) Ahmed, Hany Mohamed Aly; Keleş, Ali; Wolf, Thomas Gerhard; Rossi-Fedele, Giampiero; Dummer, Paul Michael Howell
    It is well known that the human dentition varies considerably in terms of the anatomy of roots, pulp chambers and root canals (1–5). This variation is obvious between tooth types, individuals and population groups and is influenced by age, caries, tooth surface loss, developmental defects, anomalies, trauma and a range of other conditions (2–5). The pulp chamber is defined as the portion of the pulp space within (or extending just apical) the anatomic crown of the tooth that contains the coronal pulp tissue and consists of the pulp horn(s) and body leading to the orifice(s) of the root canal(s) (6, 7). The shape, size and position of the chamber originally reflects the anatomy of the crown (8), but is particularly subject to morphological changes as a result of age and as a defensive mechanism against irritation
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    Removal efficiency of a fast setting pozzalan-based bioactive cement: A micro CT study
    (Bmc, 2024) Çetinkaya, Feyza; Çıkman, Ahter Sanal; Keleş, Ali; Arıcıoğlu, Banu
    AimThe aim of this study was to evaluate the removal efficiency of PRMTA and ECMPremixed applied to the coronal third according to the RET by UI and to examine the effect of different solutions on material removal. Materials and methods40 permanent upper central teeth were used to simulate immature teeth. The samples were irrigated with 1.5% NaOCl and calcium hydroxide was placed. Samples were incubated in PBS. Then irrigation was done with 17% EDTA, the samples were randomly divided into 2 groups (n = 20):Group 1: PRMTA, Group 2: ECM Premixed. The materials were placed in the samples. Then the samples were scanned with micro-CT. Materials were removed by UI. Micro-CT scan of the samples was performed. Each material group was divided into 2 subgroups (n = 10): Group1 was MTAD, group2 was irrigated with 10% CA; then micro-CT was performed. Obtained images were positioned in DataViewer and analyzed with CTAn. The obtained data were statistically analyzed in IBM SPSS 25. The significance level was determined as 5%. ResultsThere was no significant difference between the initial volumes of the materials (p > 0.05). The amount of the remaining material after UI was significantly higher in the PRMTA (0.7471%) group compared to the ECM Premixed (0.0093%). There was no significant difference in terms of remaining material after irrigation with MTAD and CA in both groups (p > 0.05). ConclusionA great deal of the materials were removed by UI under the operation microscope. ECM Premixed was removed more effectively compared to the PRMTA. And, acidic solutions did not provide any additional benefit in material removal.
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    Shaping ability of WaveOne Gold and OneReci by using two apical sizes: A micro-computed tomographic assessment
    (PeerJ Inc, 2023) Çiftçioğlu, Elif; Keleş, Ali; Dinçer, Gözde Akbal; Ateş, Melis Oya; Küçükay, Enver Sedat
    Backround. OneReci (MicroMega, Besan,con, France) is a recently introduced single -file reciprocating system with scarce information revealed on its shaping ability. This study aimed to compare the shaping abilities of OneReci and a well-documented single-file reciprocating system WaveOne Gold (WOG; Dentsply Maillefer, Ballaigues, Switzerland) and evaluate the effect of increased apical enlargement on the preparation quality, using micro-computed tomography (micro-CT).Methods. After an initial micro-CT scanning, twenty mesial root canals of mandibular molars were anatomically matched. The canals were assigned to two experimental groups (n = 10), using OneReci or WOG in different canals of the same root. The glide paths were created, and root canals were prepared twice, using size 25 and 35 instruments of the systems, respectively. The specimens were scanned with micro -CT after each preparation. The increase in canal volume, amount of dentin removal, unprepared root canal surface, canal transportation, centering ratio and preparation times were assessed. The data were analysed with independent sample t-tests, variance analyses, Friedman and Mann-Whitney U tests. The significance level was set at 5%.Results. Each preparation increased the canal volume and dentin removal while decreasing the unprepared root surface. The difference between the systems became significant after preparation with size 35 instruments (p < 0.05). Regarding canal transportation and centering ratio, the difference was insignificant (p > 0.05). The first preparation step (glide path + size 25 instrument) was significantly faster in the OneReci group (p < 0.05).Conclusions. Preparation with size 25 instruments of the systems appeared to be safe with similar shaping performances. Larger apical preparation promoted significantly higher dentin removal, volume increase, and prepared surface area in WOG.
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    Shaping outcomes of reciproc blue and rotate in roots canals with band-shaped isthmuses: Micro-CT study
    (Springer Heidelberg, 2023) Keskin, Cangül; Pirimoğlu, Burcu; Çiftçioğlu, Elif; Dinger, Esma; Keleş, Ali
    Objective This study assessed the outcome of shaping the mesial roots of mandibular first molars containing band-shaped isthmuses with an isthmus floor located at the apical third with Reciproc Blue and Rotate instruments in terms of canal transportation, canal aberrations and unprepared apical canals.Materials and methods Pair-matched mesial roots of mandibular first molars according to their isthmus location (distance from apical foramina) and size were constructed based on quantitative measurements (length, major and minor diameter at isthmus roof and floor) on preoperative micro-CT scanning (n = 10). The pair-matched specimens were prepared either using Reciproc Blue R25 (25.08v) or Rotate (15.04, 20.05, 25.06) instruments and then subjected to a second micro-CT scanning. Micro-CT scans were analysed to evaluate the canal transportation at the apical foramen and isthmus floor levels and the frequency of procedural errors (separated instruments, artificial canal preparation, cross shaping and unprepared apical canals). Canal transportation values were compared using Mann-Whitney U, and the distribution of procedural errors was compared with chi-square tests with a 5% significance threshold.Results Greater transportation values were detected in the apical foramen level compared to the isthmus floor in both groups. No significant difference was detected between Rotate and Reciproc Blue groups in terms of absolute transportation values and the incidence of procedural errors (p > .05).Conclusion Preparation of mesial root canals containing a band-shaped isthmus at the apical portion with Reciproc Blue and Rotate instruments caused transportation of the original canal position at the isthmus floor and the apical foramen levels and resulted in procedural errors.Clinical relevanceThis ex vivo micro-CT study using controlled pair-matched specimens showed that presence of a band-shaped isthmus complicates canal preparation procedure irrespective of the preparation systems.