Australian Endodontic Journal最新文献

A novel system to classify root and canal morphology was recently introduced (Ahmed et al. 2017). This systematic review aimed to answer the following research question: Does the Ahmed et al. system provide a more accurate and practical classification of root and canal anatomy compared to other classifications? A literature search was conducted in Google Scholar, Scopus and Wiley Online Library to identify the citation counts for the article entitled ‘A new system for classifying root and root canal morphology; doi.org/10.1111/iej.12685’. After removal of duplicates and unrelated articles, 15 studies were included and analysed. All studies compared the Ahmed et al. system with the Vertucci classification. Results revealed that both systems were able to classify simple canal configurations in single-rooted anterior and premolar teeth, disto-buccal and palatal roots of maxillary molars. However, the Ahmed et al. system provided more accurate and comprehensive categorisations of single-rooted teeth with complex canal anatomy, multi-rooted maxillary and mandibular premolars and the mesio-buccal root of maxillary molars. Further evidence on the utility of the Ahmed et al. system is required using other diagnostic devices especially in molars.

The aim of the study was to evaluate the impact of kinematics and irrigation protocols on the extrusion of apical debris during removal of different obturation techniques. A total of 144 single-rooted teeth were instrumented and obturated with Thermafil+AH Plus, Thermafil+AH Plus Bioceramic and single gutta-percha cone+AH Plus Bioceramic. Samples were divided according to the retreatment kinematics: continuous rotation or Jeni motion. Each sub-group was subjected to conventional irrigation or irrigation activated by EDDY. Extruded debris was collected in Eppendorf tubes, weighted and retreatment time was digitally recorded. Data were analysed with two-way ANOVA (p < 0.05). Debris extrusion was not significantly different between all groups. EDDY activation system and CanalPro Jeni required significantly longer time compared with other groups to remove Thermafil+AH Plus and single cone+AH Plus Bioceramic. Within current limitations, obturation technique, irrigation protocol and kinematics tested had no influence on apical extrusion debris, while they significantly impacted the retreatment time.

This CBCT-based study analysed morphometric relationships in Mesio-Buccal (MB) roots of maxillary first molars (MFM). 133 MFM with two MB canals were assessed and classified using Vertucci's classification. MB roots' length and MB1-MB2 canals inter-orifice distances (IOD) were noted. The data were analysed using SPSS software. The most frequently present canal was type IV (59.4%) followed by type II (40.6%). Mean MB roots' length for canals exhibiting type IV was 9.26 ± 0.21 mm and of those exhibiting type II was 12.8 ± 0.42 mm. Statistically significant relationship was found between MB root length and canal type. Mean IOD for type II and type IV canals was 2.4 ± 0.47 and 3.8 ± 0.21 mm, respectively. Statistically significant relationship was found between IOD and canal type. Length of MB root and IOD had a significant association with canal type present in MFM. This knowledge can enhance clinicians' understanding of canal morphology which can increase predictability and success rate of endodontic treatment.

Fears and difficulties of Moroccan dental students regarding endodontic access cavity were evaluated among 3 items: (i) teachers, (ii) student confidence and (iii) access cavity protocol. A three Likert scale was used to rate 24 statements. Specific scores between 1 and 3 and mean scores between 0 and 1 were used to assess statements and items, respectively. Among 116 students, the mean score of difficulty related to teachers (0.48 ± 0.14) was significantly low (p < 0.001) compared to student confidence (0.69 ± 0.12) and cavity protocol (0.68 ± 0.08). The number of teachers was esteemed insufficient, additional training sessions were requested and maxillary teeth and molars were rated the most difficult with specific scores of 1.91 ± 0.80, 2.72 ± 0.61, 2.22 ± 0.67 and 2.47 ± 0.74, respectively. The highest specific score referred to the risk of making ledges (2.8 ± 0.56) or perforations (2.76 ± 0.59). Students expressed a lack of confidence, difficulty with upper molars and fears of making procedural errors.

Optimal bonding of adhesive restorations to dentin is crucial to prevent microleakage and enhance the survival of root-filled teeth. The aim of this study was to investigate the effect of chlorhexidine (CHX), alexidine (ALX) and octenidine dihydrochloride (OCT) on the bond strength of resin composites to coronal dentin. Human coronal dentin specimens were treated with 2% CHX, 0.1% ALX, 0.1% OCT or saline then restored with traditional or bulk-fill resin composites. The adhesion strength between the resin and dentin was measured using the microtensile bond strength and failure mode was determined using a stereomicroscope. Treatment with ALX and OCT resulted in significantly greater μTBS compared with CHX and saline, irrespective of the resin composite used. Alexidine treatment predominantly resulted in mixed failure, while adhesive failures were frequently observed in CHX and saline-treated dentin. In conclusion, final irrigation with ALX or OCT improved the bonding of resin composites to dentin.

The aim of this study was to compare the cyclic fatigue resistance of nickel-titanium instruments inside single and double-curved canals at different temperatures. 160 HyFlex EDM #20.05 (HEDM), VDW.ROTATE #20.05 and #25.06, Mtwo #25.06 were randomised (n = 10) for the dynamic cyclic fatigue tests according to the curvature (i.e. single and double) at 20° ± 1°C and 35° ± 1°C. The number of cycles to fracture (NCF) was analysed by two-way ANOVA with p < 0.05. Fatigue resistance of all instruments significantly decreased at body temperature in single and double curvatures, except for HEDM in double curvature. The NCF was significantly lower in double curvature than single at both temperatures for all files, except for VDW.ROTATE #20.05 at 35° ± 1°C. Within the study limitations, temperature significantly impaired cyclic fatigue resistance of all files except HEDM #20.05 in double curvature. Similarly, double curvature had a detrimental effect on cyclic fatigue resistance of all files except for VDW.ROTATE #20.05 at body temperature.

The purpose of this study was to compare the impact of different irrigation protocols on debris extrusion. Single-rooted teeth were distributed into groups based on the irrigation protocols (n = 40): 2.5% NaOCl (biomechanical preparation: 20 mL and final irrigation: 5 mL); 2.5% NaOCl (biomechanical preparation: 20 mL) + 17% EDTA (final irrigation: 2 mL) + 2.5% NaOCl (final irrigation: 3 mL); and a mixture of 5% NaOCl +18% HEDP (biomechanical preparation: 20 mL and final irrigation: 5 mL). The canals were prepared using a reciprocating instrument size 40/0.06. For final irrigation, the groups were reassigned based on the agitation methods (n = 10): (a) no agitation; (b) ultrasonic; (c) sonic; and (d) continuous rotation. The control group (n = 10) received saline solution without agitation. The amount of debris extruded was measured by weight and analysed using One-way ANOVA (α < 0.05). The subgroups treated with NaOCl + HEDP mixture showed a significantly higher amount of extruded debris (p < 0.05), while there was no difference among agitation methods in all groups (p > 0.05).

This study evaluated the management preferences in a deep carious vital tooth. A questionnaire was e-mailed to members of the Turkish Dental Association. The questionnaire included a photograph and radiographs of an extremely deep carious molar (#16) of a 30-year-old man suffering from cold and chewing sensitivity. The dentists were asked to choose treatments for pulp exposure of <1, 1–2, and ≥2 mm and a permanent restoration. Chi-squared test was used to analyse data (p < 0.05). 504 (4.84%) of 10 411 dentists responded. When the pulp exposure was <1 mm: direct pulp capping (84.9%); 1–2 mm: root canal treatment (49.6%); ≥2 mm: root canal treatment (85.7%) were the most preferred treatments. 69.6% of the respondents chose direct composite restorations. If the tooth would be an abutment, most respondents preferred root canal treatment, regardless of the perforation size. The extent of pulp exposure and the type of permanent restoration influenced the treatment decision-making process.

This study investigated the concurrency of additional canals in mandibular incisors and the second mesiobuccal canal in maxillary first molars among the Chinese population. In total, 8644 cone-beam computed tomography images from 8644 patients with bilateral mandibular incisors and maxillary first molars were examined. The data were analysed using Chi-square test, binary logistic regression analysis and receiver operating characteristic curve. Among the patients with additional canals in mandibular central and lateral incisors, 96.2% and 95.5% of them had second mesiobuccal canal in maxillary first molars, respectively. Additional canals of mandibular incisors and second mesiobuccal canal in maxillary first molars exhibited a concurrent relationship. The prevalence of second mesiobuccal canal in maxillary first molars increased with the number of mandibular incisors with additional canals. Moreover, when there was at least one mandibular incisor with additional canals, the presence of the second mesiobuccal canal in maxillary first molars could be highly expected.