Endodontic Treatment of a Dilacerated Maxillary Second Premolar With a Severely Curved Root Canal: A Case Report and Literature Review.

Dilaceration is a developmental anomaly characterized by a sharp change in the axial inclination between the crown and the root of a tooth. Severe root curvature in a dilacerated tooth can greatly complicate root canal treatment. This case report details the successful endodontic treatment of a dilacerated maxillary second premolar with significant root curvature. It highlights the importance of a thorough understanding of root canal anatomy and demonstrates the effectiveness of using pre-curved hand files along with heat-treated nickel-titanium rotary instruments in navigating complex root structures to achieve successful treatment outcomes.

Navigating Challenges in the Management of Mandibular Third Molars With Radix Paramolaris: A Case Report.

This study aims to shed light on a contemporary approach to preserving third molars instead of opting for immediate extraction. Third molars are known for their diverse shapes and unique anatomy, making root canal treatment a complex task due to limited access. However, there are situations where it is crucial to retain these molars, such as when they provide support or for self-transplantation purposes. The case report focuses on a 33-year-old female patient who presented with pulp necrosis and acute apical periodontitis in the lower right third molar. Instead of extraction, a two-visit conventional root canal treatment was planned. During the initial diagnostic radiographs, only two visible roots were observed, illustrating the typical anatomy of the third molar. However, an unforeseen additional root, referred to as radix paramolaris, was encountered in the mesiobuccal region during the access opening, presenting numerous challenges in the treatment process. Thankfully, advancements in dental technology, such as magnification aids, ultrasonic tips and flexible nickel-titanium (NiTi) rotary files, have rendered the management of such intricate cases more attainable. In conclusion, dealing with intricately curved canals in difficult-to-reach teeth like third molars has become more achievable with technological progress, although the operator's skill and experience remain crucial for effective management.

Buckling Susceptibility of a K-File during the Initial Negotiations of Narrow and Curved Canals Using Different Manual Techniques.

(1) Background: One possible way to investigate the potential impact or susceptibility of buckling on different manual techniques is to measure compressive loads during canal negotiation. The higher their values, the easier and quicker the critical load level to buckling is reached, leading to possible instrument lateral deformation. The objective of the present study was to investigate the impacts of compressive loads on a small K-file manipulated with different techniques for canal negotiation in simulated narrow and curved canals. (2) Methods: The tooth model selected was a plastic double-curved premolar 23 mm long (DRSK Group AB, Kasernvagen 2, SE-281 35, Hassleholm, Sweden) with an extremely narrow canal lumen to mimic a very difficult anatomical scenario. An experienced endodontist performed the negotiation of 90 of these artificial teeth randomly assigned to 3 different groups of 30 blocks each, respectively, using 3 different techniques: Group A: watch winding/pull (WW) motion; Group B: balanced forces (BF) technique; Group C: envelope of motion (EOM). The measurement system was based on the use of a dynamometer, Instron, Ltd. (model 2525-818 2kN f.s.), linked to a data acquisition unit HBM MGC+ to test all the compression and tensile loads, including all the peaks. (3) Results: All data acquired were processed by the CATMAN AP HBM software. Multiple comparisons for the highest compressive loads estimated the mean difference between WW vs. BF techniques of 3.60 [95% confidence interval (CI): 2.85 to 4.35, p < 0.001], WW vs. EOM of −1.76 (95% CI: −2.11 to 1.40, p < 0.001), and BF vs. EOM −5.36 (95% CI: −6.04 to −4.67, p < 0.001). (4) Conclusions: In conclusion, among the tested manual motions, the BF technique (Group B) was the most susceptible to buckling with the highest compressive load. WW motion (Group A) and EOM (Group C) were less susceptible to buckling than the BF technique. Therefore, a pressure-free manipulation of manual files, such as WW motion or EOM, can help reduce the susceptibility to buckling during the negotiation of narrow-curved canals.

Development of Innovative Contra-angle Handpiece Device with Piston Movement for Root Canal Preparation.

INTRODUCTION: The purpose of this study was to assess the optimal amplitude and weight of the newly developed contra-angle handpiece. The handpiece uses piston movement without using an endodontic motor and enables a safe, quick, and reliable canal preparation. METHODS: A prototype handpiece was designed. Instrumentation was performed on root canal resin blocks by 20 operators in 3 groups: the prototype handpiece with an H file (a stainless steel #25 manual H file, the piston group), a manually standardized technique with a K file (stainless steel #15-25 K files, the manual group), and a nickel-titanium (NiTi) reciprocating file with an endodontic motor (Reciproc Blue R25 [VDW, Munich, Germany], the NiTi group). Transportation of the canal center line and the time required for preparation were measured and statistically analyzed. RESULTS: The optimal condition was an amplitude of 1.35 mm and a weight of 61.0 g. Transportation of the canal center was observed in all groups. A statistically significant difference was found at 2.0-3.0 mm from the apical foramen between the piston or NiTi group and the manual group, but no significant difference was found between the piston and NiTi groups. The least transportation was found in the NiTi and piston groups. The handpiece with a #25 H file demonstrated a good centering ability, similar to the NiTi file, which enabled speedy preparation. The time required for preparation between the piston or NiTi group and the manual group was statistically different. No significant difference was observed between the piston and NiTi groups (P < .05). CONCLUSIONS: We concluded that the newly designed handpiece achieved efficient canal preparation and negotiation. The handpiece could avoid endodontic accidents, including ledge formation, instrument separation, and perforation.

Shaping Ability of HyFlex EDM and ProTaper Next Rotary Instruments in Curved Root Canals: A Micro-CT Study.

AIM: The aim of this study is to evaluate and compare the shaping ability of HyFlex™ EDM (HFEDM) and ProTaper Next (PTN) rotary instruments in curved root canals by using micro-computed tomography (micro-CT) imaging. MATERIALS AND METHODS: A total of 22 mandibular molar teeth having separate mesial canals with 20 to 30° curvatures were randomly divided into two groups and instrumented with HFEDM (OneFile) or PTN (X1 and X2). Pre- and post-instrumentation micro-CT scans were obtained. Mesiodistal canal transportation and centering ability were evaluated in four cross-sections (2, 4, 6, and 8 mm from apex). Changes in canal volume and surface area were measured for a 10-mm standardized area of interest. Kolmogorov-Smirnov and Shapiro-Wilk tests were used to assess the normality and homogeneity. Independent and paired t tests and one-way ANOVA were used to analyze data at the p < 0.05 level. RESULTS: Compared to PTN, HFEDM showed significantly less mesiodistal canal transportation and improved centering ability in cross-section L6 (p < 0.05). The instruments showed similar increases in volume and surface area of the canals, with minor insignificant differences. CONCLUSION: HFEDM and PTN files were safe to use in curved canals and showed similar shaping ability, while respecting the original anatomies. HFEDM OneFile performed better at the vicinity of the danger zone in terms of mesiodistal canal transportation and centering ability.

Comparison of ProTaper Next and HyFlex instruments on apical debris extrusion in curved canals.

AIM: To evaluate the amount of apically extruded debris after root canal instrumentation with ProTaper Next and HyFlex instruments in curved root canals. METHODOLOGY: Forty extracted mandibular first molar teeth with curved mesial roots and of similar lengths were instrumented using ProTaper Next or HyFlex instruments. The extruded debris was collected into pre-weighed Eppendorf tubes. The tubes were stored in an incubator at 68 °C for 5 days. The tubes were weighed to obtain the final dry weight of the extruded debris. The weight of the extruded debris was determined by subtracting the initial weight from the final weight. Distribution of data was determined by Shapiro-Wilk test. Continuous variables were compared with the Independent Sample t-test or Mann-Whitney U-test. The significance level was set at P = 0.05. RESULTS: Both instruments were associated with apical debris extrusion. The HyFlex group had significantly less debris extrusion than the ProTaper Next group (P = 0.014). CONCLUSION: HyFlex CM was associated with significantly less apical extrusion than ProTaper Next.

The sealing ability of resilon and gutta-percha in severely curved root canals: an in vitro study.

OBJECTIVE: The aim of this study was to compare the apical seal of curved canals obturated with Resilon/Epiphany with gutta-percha/AH Plus. MATERIALS AND METHODS: Thirty-four extracted human mandibular molars with 25-40 degree canal curvature of the mesial root were selected for this study. After preparation, the mesiobuccal canals were obturated with gutta-percha and AH- Plus sealer (group G) or Resilon and Epiphany sealer (group R). Four specimens served as control. Microleakage was evaluated after passing 3 and 30 days using the fluid filtration technique. The data were analyzed statistically using parametric tests. RESULTS: In the 3-day evaluation, the mean microleakage in group R was significantly less than in group G (P< 0.05). After 30 days, there was no significant difference between the two groups (P> 0.05). In group G, the leakage values at the end of 30 days were significantly less than values at the end of 3 days. Although in group R the mean leakage decreased after 30 days, this reduction was not statistically significant. CONCLUSION: Resilon/Epiphany provided a better seal than gutta-percha/AH-Plus in severely curved root canals immediately after obturation, although with the passage of time, Resilon/Epiphany was equivalent to gutta-percha/AH Plus in sealing properties.

Scanning electron microscopic evaluation of dentinal tubule penetration of Epiphany in severely curved root canals.

OBJECTIVE: The purpose of this study was to compare the depth of dentinal tubule sealer penetration in the apical thirds of severely curved root canals obturated with Resilon/Epiphany self-etch (SE) or gutta-percha/AH Plus using scanning electron microscopy. MATERIALS AND METHODS: A total of 34 extracted human mandibular molars with 25-40° curvature of the mesial root canal were selected for this study. After preparation, the mesiobuccal canals were randomly obturated with gutta-percha and AH Plus sealer or Resilon and Epiphany SE sealer. Sealer penetration was evaluated in 2 mm sections of the apical thirds of roots using scanning electron microscopy. Data were analyzed using the independent t-test and Mann-Whitney U-test, with significance set at P < 0.05. RESULTS: Mean tubular penetration depth did not differ significantly between Resilon SE (172.22 µm) and AH Plus (122.18 µm; P > 0.05). The density of sealer tags in the apical thirds of root canals was also equivalent (P > 0.05). CONCLUSION: Average penetration into dentinal tubules in the apical thirds of severely curved roots did not differ significantly between Epiphany SE and AH Plus.