Materials

Research

9 pages, 2002 KiB

Open AccessArticle

Effect of Different Downward Loads on Canal Centering Ability, Vertical Force, and Torque Generation during Nickel–Titanium Rotary Instrumentation

by Keiichiro Maki, Arata Ebihara, Hayate Unno, Satoshi Omori, Taro Nakatsukasa, Shunsuke Kimura and Takashi Okiji

Materials 2022, 15(8), 2724; https://doi.org/10.3390/ma15082724 - 7 Apr 2022

Cited by 2 | Viewed by 1914

Abstract

This study aimed to examine how downward loads influence the torque/force and shaping outcome of ProTaper NEXT (PTN) rotary instrumentation. PTN X1, X2, and X3 were used to prepare J-shaped resin canals employing a load-controlled automated instrumentation and torque/force measuring device. Depending on [...] Read more.

This study aimed to examine how downward loads influence the torque/force and shaping outcome of ProTaper NEXT (PTN) rotary instrumentation. PTN X1, X2, and X3 were used to prepare J-shaped resin canals employing a load-controlled automated instrumentation and torque/force measuring device. Depending on the torque values, the handpiece was programmed to move as follows: up and down; downward at a preset downward load of 1 N, 2 N or 3 N (Group 1N, 2N, and 3N, respectively; each n = 10); or upward. The torque/force values and instrumentation time were recorded, and the canal centering ratio was calculated. The results were analyzed using a two-way or one-way analysis of variance and the Tukey test (α = 0.05). At the apex level, Group 3N exhibited the least canal deviation among the three groups (p < 0.05). The downward force was Group 3N > Group 2N > Group 1N (p < 0.05). The upward force, representing the screw-in force, was Group 3N > Group 1N (p < 0.05). The total instrumentation time was Group 1N > Group 3N (p < 0.05). In conclusion, increasing the downward load during PTN rotary instrumentation improved the canal centering ability, reduced the instrumentation time, and increased the upward force. Full article

(This article belongs to the Special Issue Endodontics)

► Show Figures

Figure 1

11 pages, 4070 KiB

Open AccessArticle

In Vitro Evaluation of the Antibacterial Activity of EndoSeal MTA, iRoot SP, and AH Plus against Planktonic Bacteria

by Siew Thong Mak, Xin Fang Leong, In Meei Tew, Endang Kumolosasi and Lishen Wong

Materials 2022, 15(6), 2012; https://doi.org/10.3390/ma15062012 - 8 Mar 2022

Cited by 9 | Viewed by 2433

Abstract

This study aimed to investigate the antibacterial activity of three endodontic sealers, AH Plus, iRoot SP, and EndoSeal MTA, against four planktonic bacteria species. The antibacterial activity of the three endodontic sealers was assessed using a modified direct contact test. Bacteria suspension of [...] Read more.

This study aimed to investigate the antibacterial activity of three endodontic sealers, AH Plus, iRoot SP, and EndoSeal MTA, against four planktonic bacteria species. The antibacterial activity of the three endodontic sealers was assessed using a modified direct contact test. Bacteria suspension of Actinomycoses viscosus, Enterococcus faecalis, Staphylococcus aureus, and Streptococcus mutans were left in contact with the sealers that were pre-set or set for 1, 3, 7, and l4 days for an hour. Freshly mixed AH Plus and EndoSeal MTA were highly effective against all four tested bacteria as no surviving bacteria were recovered after treatment. Meanwhile, freshly mixed iRoot SP was not able to kill all bacteria, regardless of the species, demonstrating a weak antibacterial effect. After 24 h, AH Plus lost its antibacterial activity. EndoSeal MTA showed a strong and extended bactericidal effect against S. aureus and S. mutans for 3 days and A. viscosus for 7 days. In conclusion, fresh AH Plus and EndoSeal MTA exhibited a potent effect against all four bacteria species. EndoSeal MTA remained effective after setting when tested against A. viscosus, S. aureus, and S. mutans. Among all tested sealers, iRoot SP demonstrates the weakest antibacterial activity. Full article

(This article belongs to the Special Issue Endodontics)

► Show Figures

Figure 1

16 pages, 5817 KiB

Open AccessEditor’s ChoiceArticle

Biocompatibility of a New Calcium Silicate-Based Root Canal Sealer Mediated via the Modulation of Macrophage Polarization in a Rat Model

by Xiaoqian Yang, Jun Tian, Mengjie Li, Weiyang Chen, He Liu, Zhejun Wang, Markus Haapasalo, Ya Shen and Xi Wei

Materials 2022, 15(5), 1962; https://doi.org/10.3390/ma15051962 - 7 Mar 2022

Cited by 14 | Viewed by 2969

Abstract

(1) Background: The EndoSequence BC Sealer HiFlow (Brasseler, Savannah, GA, USA) has recently been introduced in clinical applications. Thus, the aims of the present study are to determine its biocompatibility in vivo and to examine its ability to drive macrophage polarization in vitro [...] Read more.

(1) Background: The EndoSequence BC Sealer HiFlow (Brasseler, Savannah, GA, USA) has recently been introduced in clinical applications. Thus, the aims of the present study are to determine its biocompatibility in vivo and to examine its ability to drive macrophage polarization in vitro and in vivo. (2) Methods: HiFlow was implanted into rat connective tissue for 7, 30 and 150 days. The microstructures and elemental compositions were determined by scanning electron microscopy-energy-dispersive X-ray spectroscopy (SEM-EDX). Hematoxylin–eosin, immunofluorescence, RT–qPCR and flow cytometry were used to elucidate the effects on inflammatory responses and macrophage polarization. (3) Results: SEM-EDX revealed the formation of surface hydroxyapatite crystal layers. Histological evaluation showed that HiFlow exhibited long-term biocompatibility because it decreased inflammatory responses and reduced the number of macrophages over time; however, tissue necrosis was observed in all the groups. RT–qPCR verified that HiFlow regulated the expression of inflammatory factors to inhibit the inflammatory response. Immunofluorescence analysis performed on in vivo samples revealed that HiFlow promoted M2-like macrophage polarization, and these results were confirmed by flow cytometry in vitro. (4) Conclusion: After 150 days of investigation, HiFlow was considered biologically acceptable, and the formation of apatite crystal layers and the promotion of M2-like macrophage polarization may contribute to its favorable biocompatibility. Full article

(This article belongs to the Special Issue Endodontics)

► Show Figures

Figure 1

12 pages, 2104 KiB

Open AccessArticle

Quantification of Bacterial DNA from Infected Human Root Canals Using qPCR and DAPI after Disinfection with Established and Novel Irrigation Protocols

by Marie-Theres Weber, Yousef Alkhafaji, Anne Pioch, Evelyn Trips, Sabine Basche, Martin Dannemann, Alan Kilistoff, Christian Hannig and Torsten Sterzenbach

Materials 2022, 15(5), 1911; https://doi.org/10.3390/ma15051911 - 4 Mar 2022

Cited by 3 | Viewed by 2557

Abstract

The removal of bacterial infections within the root canal system is still a challenge. Therefore, the cleansing effect of established and new irrigation-protocols (IP) containing silver diamine fluoride (SDF) 3.8% on the whole root canal system was analyzed using quantitative PCR (qPCR) and [...] Read more.

The removal of bacterial infections within the root canal system is still a challenge. Therefore, the cleansing effect of established and new irrigation-protocols (IP) containing silver diamine fluoride (SDF) 3.8% on the whole root canal system was analyzed using quantitative PCR (qPCR) and 4′,6-diamidino-phenylindole-(DAPI)-staining. Extracted human premolars were instrumented up to F2 (ProTaper Gold) under NaCl 0.9% irrigation and incubated with Enterococcus faecalis for 42 days. Subsequently, different ultrasonically agitated IP were applied to the roots: control (no irrigation), 1. NaOCl 3%, EDTA 20%, CHX 2%, 2. NaOCl 3%, EDTA 20%, 3. NaOCl 3%, EDTA 20%, SDF 3.8%, 4. SDF 3.8%, and 5. NaCl 0.9%. One half of the root was investigated fluorescent-microscopically with DAPI. The other half was grinded in a cryogenic mill and the bacterial DNA was quantified with qPCR. The qPCR results showed a statistically significant reduction of bacteria after the application of IP 1, 2, and 3 compared to the control group. While IP 4 lead to a bacterial reduction which was not significant, IP 5 showed no reduction. These data corresponded with DAPI staining. With qPCR a new molecular-biological method for the investigation of the complete root canal system was implemented. The novel IP 3 had an equally good cleansing effect as the already established IP. Full article

(This article belongs to the Special Issue Endodontics)

► Show Figures

Figure 1

10 pages, 2158 KiB

Open AccessArticle

Distrontium Cerate as a Radiopaque Component of Hydraulic Endodontic Cement

by Kunlanun Dumrongvute, Sherif Adel, Takahiro Wada, Nobuyuki Kawashima, Chinalai Piyachon, Hiroshi Watanabe, Tohru Kurabayashi, Takashi Okiji and Motohiro Uo

Materials 2022, 15(1), 284; https://doi.org/10.3390/ma15010284 - 31 Dec 2021

Cited by 5 | Viewed by 2294

Abstract

This study aimed to synthesize distrontium cerate (2SrO·CeO₂: S₂Ce) and evaluate its properties as an alternative component of the endodontic cement. S₂Ce cement was prepared through calcination of strontium hydroxide and cerium carbonate. Subsequently, the crystal phase [...] Read more.

This study aimed to synthesize distrontium cerate (2SrO·CeO₂: S₂Ce) and evaluate its properties as an alternative component of the endodontic cement. S₂Ce cement was prepared through calcination of strontium hydroxide and cerium carbonate. Subsequently, the crystal phase was confirmed using X-ray diffraction. S₂Ce cement exhibited a rapid setting time (121 min) and achieved a high compressive strength (72.1 MPa) at 1 d after mixing, comparable to the compressive strength of a commercial mineral trioxide aggregate (MTA) cement (ProRoot MTA) after 28 d post mixing. However, the compressive strength decreased after 28 d of storage when the W/P ratio was 0.30–0.40 (p < 0.05). Ion dissolution test of the S₂Ce cement showed that strontium ions were released after immersion in water (5.27 mg/mL after 1 d), whereas cerium dissolution was not detected. S₂Ce exhibited approximately three times higher radiopacity (9.0 mm aluminum thickness equivalent) compared to the commercial MTA (p < 0.05). These findings suggest that S₂Ce is a possible component for hydraulic endodontic cement that demonstrates a rapid setting and high radiopacity. Full article

(This article belongs to the Special Issue Endodontics)

► Show Figures

Figure 1

12 pages, 2781 KiB

Open AccessArticle

Post-Fatigue Fracture and Marginal Behavior of Endodontically Treated Teeth: Partial Crown vs. Full Crown vs. Endocrown vs. Fiber-Reinforced Resin Composite

by Roland Frankenberger, Julia Winter, Marie-Christine Dudek, Michael Naumann, Stefanie Amend, Andreas Braun, Norbert Krämer and Matthias J. Roggendorf

Materials 2021, 14(24), 7733; https://doi.org/10.3390/ma14247733 - 15 Dec 2021

Cited by 18 | Viewed by 5151

Abstract

Objectives: To investigate in vitro post-fatigue fracture behavior of endodontically treated molars having been differently restored. Methods: A total of 120 extracted human molars were used. A total of 120 specimens in 14 test groups and one control group (n = 8) [...] Read more.

Objectives: To investigate in vitro post-fatigue fracture behavior of endodontically treated molars having been differently restored. Methods: A total of 120 extracted human molars were used. A total of 120 specimens in 14 test groups and one control group (n = 8) were root canal treated. After postendodontic sealing and build-up (AdheSE Universal, SDR), additional MOD preparations were cut. Postendodontic restorations were: Direct restorations (Tetric EvoCeram BulkFill bonded with AdheSE Universal and EverX Posterior/Essentia bonded with G-Premio Bond; as filling (F) or direct partial crown (DPC) after reducing the cusps 2 mm; indirect adhesive restorations (partial crown/PC vs. full crown/FC): e.max CAD, Celtra Duo, both luted with Variolink Esthetic; indirect zirconia restorations (partial crown/PC vs. full crown/FC), luted with RelyX Unicem 2; indirect non-bonded cast gold restorations (partial crown/PC vs. full crown/FC; Degunorm), luted with Ketac Cem. Before and after 300,000 thermocycles (5/55 °C) and 1.2 Mio. A total of 100 N load cycles, replicas were analyzed under a SEM for marginal quality in enamel and dentin (where applicable) and finally, specimens were loaded until fracture. Results: In direct groups, there was no difference between RC and FRC in fracture strength (p > 0.05); however, direct partial crowns showed higher post-fatigue fracture resistance. Regarding marginal quality, intracoronal FRC restorations exhibited more gap-free margins in enamel than RC. In the indirect groups, there was no significant difference between partial and full crowns in any of the adhesively luted ceramic groups regarding post-fatigue fracture resistance. Zirconia partial crowns exhibited significantly lower marginal quality in enamel. Indirect groups performed significantly better than direct groups in fracture resistance. Within the indirect restorations, both cast gold groups and zirconia full crowns exhibited the highest fracture resistance being superior to control teeth. Significances: Within the limits of this in vitro investigation, it can be concluded that any kind of indirect restoration with cusp replacement is suitable for ETT restoration when a certain cavity extension is exceeded. All indirect restorations, i.e., endocrowns, partial crowns, and full crowns showed a promising performance after in vitro fatigue-loading. Full article

(This article belongs to the Special Issue Endodontics)

► Show Figures

Figure 1

11 pages, 6318 KiB

Open AccessArticle

The Effect of Different Condition of Pulpal Pressure on Microtensile Bond Strength of Several Dentin Bonding Agents on Deep and Superficial Dentin

by Marco Montanari, Luca Fiorillo, Gabriele Cervino, Sergio Sambataro, Alan Scott Herford and Marco Cicciù

Materials 2021, 14(20), 6200; https://doi.org/10.3390/ma14206200 - 19 Oct 2021

Cited by 3 | Viewed by 2431

Abstract

The objective of this study was to examine the effect of different conditions of simulated hydrostatic pulpal pressure on the μTBS of HEMA-based and HEMA-free dentin bonding agents (DBAs). The influence of dentin location (deep and superficial) on μTBS was also evaluated. Flat [...] Read more.

The objective of this study was to examine the effect of different conditions of simulated hydrostatic pulpal pressure on the μTBS of HEMA-based and HEMA-free dentin bonding agents (DBAs). The influence of dentin location (deep and superficial) on μTBS was also evaluated. Flat coronal dentin surfaces of extracted human molars were prepared. Three groups of resin-bonded specimens were exposed to different pulpal pressures. Pulpal pressure was maintained for 20 min for each group. A flowable resin composite was used for coronal build-up. The bonded teeth were sectioned and, after 24 h of water storage, stressed to failure using the microtensile tester (μTBS). Failed samples were analyzed by SEM inspection. HEMA-based DBAs were much more sensitive to pulpal pressure conditions than non-HEMA-containing DBAs. Pulpal pressure had a greater influence in deep dentin. The HEMA-free DBA was insensitive to the presence or absence of pulpal pressure condition. SEM inspection confirmed a relationship between the presence of voids inside the HEMA-based DBAs layer and the lower μTBS results. HEMA-based DBAs are more sensitive to pulpal pressure conditions than HEMA-free DBAs. Interestingly, HEMA-free DBA showed a greater number of water droplets at resin–dentin interface in all tested conditions. Full article

(This article belongs to the Special Issue Endodontics)

► Show Figures

Figure 1

13 pages, 1802 KiB

Open AccessArticle

Vital Pulp Therapy in Aesthetic Zone-Identifying the Biomaterial That Reduces the Risk of Tooth Discolouration

by Joanna Metlerska, Irini Fagogeni, Marcin Metlerski and Alicja Nowicka

Materials 2021, 14(20), 6026; https://doi.org/10.3390/ma14206026 - 13 Oct 2021

Cited by 4 | Viewed by 2362

Abstract

Calcium silicate-based cements are biocompatible materials for vital pulp therapy. However, they discolour the tooth tissue, which is important for the aesthetics of the anterior teeth. The aim of this study was to investigate the effect of calcium silicate-based cements on tooth discolouration. [...] Read more.

Calcium silicate-based cements are biocompatible materials for vital pulp therapy. However, they discolour the tooth tissue, which is important for the aesthetics of the anterior teeth. The aim of this study was to investigate the effect of calcium silicate-based cements on tooth discolouration. The study included 70 extracted bovine incisors. The crown of the tooth was cut off from the root, 2 mm below the cement-enamel junction. The pulp tissue was removed via a cervical cut with a barbed broach. The teeth were randomly divided into five experimental, one positive, and one negative control groups. The evaluated materials included Biodentine, Ortho MTA, Retro MTA, MTA Plus, MTA Repair HP, and in the positive group, ProRoot MTA. A VITA Easyshade Compact 5.0 spectrophotometer was used before the application, after 1 week, 1 month, 3 months, and 6 months. The significance levels were set at p < 0.05. All materials significantly changed the teeth colour (p < 0.05). However, Ortho MTA, ProRoot MTA, MTA Plus, and Biodentine (ΔE > 6) caused maximum colour change after 6 months. While the ProRoot MTA, Ortho MTA, and MTA Plus caused grey discolouration, Biodentine darkened the shade of the base colour. Thus, Retro MTA and MTA Repair HP can be safely used in the aesthetic dentition zone. According to these clinical results, the possibility of using Biodentine, due to its lack of gray discoloration, can be considered. Full article

(This article belongs to the Special Issue Endodontics)

► Show Figures

Figure 1

14 pages, 5169 KiB

Open AccessArticle

Effect of Core Mass and Alloy on Cyclic Fatigue Resistance of Different Nickel-Titanium Endodontic Instruments in Matching Artificial Canals

by Sebastian Bürklein, Lennart Zupanc, David Donnermeyer, Karsten Tegtmeyer and Edgar Schäfer

Materials 2021, 14(19), 5734; https://doi.org/10.3390/ma14195734 - 1 Oct 2021

Cited by 14 | Viewed by 3205

Abstract

Instrument failure during root canal preparation is still a concern among endodontists. However, it remains unclear whether the use of more martensitic alloys or the cross-sectional design parameters (i.e., core mass) significantly improve fracture resistance. The aim of the study was to evaluate [...] Read more.

Instrument failure during root canal preparation is still a concern among endodontists. However, it remains unclear whether the use of more martensitic alloys or the cross-sectional design parameters (i.e., core mass) significantly improve fracture resistance. The aim of the study was to evaluate the impact of core mass and alloy on dynamic cyclic fatigue resistance of nickel-titanium endodontic instruments in matching artificial canals at body temperature. Two groups were tested. (A) taper 0.04: F360 (Komet, Lemgo, Germany), Twisted file (Sybron Endo, Glendora, CA, USA) (=TF), JIZAI (Mani, Tochigi, Japan) (=J_04) (all size #25) and the variable tapered TruNatomy (Dentsply, Ballaigues, Switzerland) (size #26) (=TN). (B) size #25; taper 0.06: (Mtwo (VDW, Munich, Germany), JIZAI (Mani) (=J_06), and variable tapered Hyflex EDM OneFile (Coltene Whaledent, Altstätten, Switzerland) (=HF). Time, number of cycles to fracture (NCF), and number and length of fractured fragments were recorded and statistically analysed using ANOVA Student-Newman-Keuls, Kruskal–Wallis or Chi-square test (significance level = 0.05). (A) TN showed the significantly shortest time until fracture, followed by TF, F360 and J_04 which also differed significantly, while NCF showed the following order: F360 < TN < TF < J_04 (p < 0.05). Only one J_04 but all instruments of the other groups fractured within the test-limit of 10 min. (B) Mtwo was significantly inferior concerning time until fracture and NCF, compared to J_06 and HF (p < 0.05), which did not differ significantly (p > 0.05). While all Mtwo instruments fractured, only four instruments failed in the other groups (p < 0.05). Within the limitations of this study, alloy and cross-sectional design (i.e., core mass) were critical factors regarding instrument failure, but none of these factors could be determined as a main parameter for increased or decreased time, and cycles to fracture. Rather, it seemed to be the interaction of multiple factors (e.g., longitudinal and cross-sectional design, alloy, and rotational speed) that was responsible for differences in the time and cycles to fracture. Nonetheless, all instruments had lifetimes that allow safe clinical use. However, the superiority or inferiority of an instrument with regard to cyclic fatigue based on laboratory results—even when identical trajectories are guaranteed—may be considered questionable, as the characteristics and design parameters of the instruments vary considerably, and the experimental setups lack additional clinical parameters and thus clinical relevance. Full article

(This article belongs to the Special Issue Endodontics)

► Show Figures

Figure 1

9 pages, 1452 KiB

Open AccessArticle

Debris Removal Using a Hydroxyapatite Nanoparticle-Containing Solution (Vector Polish) with Sonic or Ultrasonic Agitation

by Michael Hülsmann, Christoph Beckmann and Steffi Baxter

Materials 2021, 14(16), 4750; https://doi.org/10.3390/ma14164750 - 23 Aug 2021

Cited by 1 | Viewed by 2166

Abstract

Chemomechanical preparation of the root canal system is considered to be the most important part of root canal treatment, including both mechanical removal of tissue remnants and dentine chips, and chemical elimination of biofilm and microorganisms. A number of different solutions and agitation [...] Read more.

Chemomechanical preparation of the root canal system is considered to be the most important part of root canal treatment, including both mechanical removal of tissue remnants and dentine chips, and chemical elimination of biofilm and microorganisms. A number of different solutions and agitation techniques have been proposed for that purpose. It was the aim of the present study to investigate whether root canal cleanliness can be improved by using a hydroxyapatite nanoparticle-containing solution with and without sonic or ultrasonic agitation. Seventy-four single-rooted teeth were divided into four experimental groups (n = 15) and two control groups (n = 7). All teeth were split longitudinally and a groove and three holes were cut into the root canal wall and filled with dentinal debris. Final irrigation was performed using sodium hypochlorite or a hydroxyapatite nanoparticle-containing solution (Vector polish) activated with a sonically or an ultrasonically driven endodontic file. Two calibrated investigators rated the remaining debris using a four-score scale. The results were analyzed using a non-parametric test with

α

< 0.05. Sonic and ultrasonic irrigation with sodium hypochlorite cleaned the grooves and holes well from debris. The hydroxyapatite nanoparticles activated by a sonic file cleaned grooves and holes equally well. Ultrasonically activated nanoparticles performance was clearly inferior. The syringe control-group left large amounts of debris in grooves and holes. The use of the hydroxyapatite nanoparticles used in this study did not improve removal of debris. Full article

(This article belongs to the Special Issue Endodontics)

► Show Figures

Figure 1

18 pages, 5074 KiB

Open AccessArticle

Prognosis of Regenerative Endodontic Procedures in Mature Teeth: A Systematic Review and Meta-Analysis of Clinical and Radiographic Parameters

by Pantaleo Scelza, Fabiano Gonçalves, Isleine Caldas, Fernanda Nunes, Emanuelle Stellet Lourenço, Sandro Tavares, Marcela Magno, Andrea Pintor, Pietro Montemezzi, Emanuele Di Edoardo, Carlos Fernando de Almeida Barros Mourão, Gutemberg Alves and Miriam Zaccaro Scelza

Materials 2021, 14(16), 4418; https://doi.org/10.3390/ma14164418 - 6 Aug 2021

Cited by 11 | Viewed by 3337

Abstract

This work aimed to investigate the use of Regenerative Endodontic Procedures (REP) on the treatment of pulp necrosis in mature teeth through systematic review and meta-analysis of evidence on clinical and radiographic parameters before and after REP. A search was performed in different [...] Read more.

This work aimed to investigate the use of Regenerative Endodontic Procedures (REP) on the treatment of pulp necrosis in mature teeth through systematic review and meta-analysis of evidence on clinical and radiographic parameters before and after REP. A search was performed in different databases on 9 September 2020, including seven clinical studies and randomized controlled trials (RCT). The methodological quality was assessed using Revised Cochrane risk-of-bias (RoB 2) and Before-and-After tools. Meta-analyses were performed to evaluate the success incidences regarding the reduction of periapical lesion and recovery of sensitivity. The certainty of the evidence was assessed using GRADE. Meta-analysis showed a high overall success of 0.95 (0.92, 0.98) I² = 6%, with high periapical lesion reduction at 12 months (0.93 (0.86, 0.96) I² = 37%) and by the end of follow-up (0.91 (0.83, 0.96) I² = 13%). Lower incidences of positive sensitivity response were identified for the electrical (0.58 (0.46, 0.70) I² = 51%) and cold tests (0.70 (0.54, 0.84) I² = 68%). The calculated levels of REP success were similar to those reported for immature teeth. With a very low certainty of evidence, the meta-analysis showed a high incidence of REP’s success for mature teeth with necrotic pulp evidenced by periapical lesion reduction and moderate positive responses to sensitivity tests. Full article

(This article belongs to the Special Issue Endodontics)

► Show Figures

Figure 1

11 pages, 2104 KiB

Open AccessArticle

Angle of Insertion and Torsional Resistance of Nickel–Titanium Rotary Instruments

by Dario Di Nardo, Alessio Zanza, Marco Seracchiani, Orlando Donfrancesco, Gianluca Gambarini and Luca Testarelli

Materials 2021, 14(13), 3744; https://doi.org/10.3390/ma14133744 - 4 Jul 2021

Cited by 19 | Viewed by 2760

Abstract

Previously published studies have investigated the influence of instrument access on cyclic fatigue resistance. However, no studies have evaluated the relationship between angulated access and torsional resistance. The aim of this study was to investigate the influence of the angle of access on [...] Read more.

Previously published studies have investigated the influence of instrument access on cyclic fatigue resistance. However, no studies have evaluated the relationship between angulated access and torsional resistance. The aim of this study was to investigate the influence of the angle of access on the torsional resistance of endodontic instruments. One hundred and eighty instruments were selected: 90 F-One Blue 25/04 and 90 HeroShaper 25/04 instruments. Three subgroups (n = 30) for each instrument type (A and B) were established according to the angle of insertion of the instruments inside the artificial canal (0°, 10° and 20°). The tests were performed using a custom-made device consisting of the following: a motor that can record torque values of 0.1 s; interchangeable stainless-steel canals with different curvature (0°, 10° and 20°) that allow the instrument’s angulated insertion and keep it flexed during testing procedures; and a vise used to secure the instrument at 3 mm from the tip. Torque limit was set to 5.5 Ncm, and each instrument was rotated at 500 rpm until fracture occurred. Torque to fracture (TtF) was registered by the endodontic motor, and the fragment length (FL) was measured with a digital caliper. Fractographic analysis was performed using a scanning electron microscopy (SEM) evaluation to confirm the cause of failure. TtF values and fragment length (FL) values were statistically analyzed using one-way analysis of variance (ANOVA) test and the Bonferroni correction for multiple comparisons across the groups with significance set to a 95% confidence level. Regarding the F-One Blue instruments, the results showed a higher TtF for group A3 (20°) than for group A1 (0°) and group A2 (10°), with a statistically significant difference between group A3 and the other two groups (p < 0.05), whereas no statistically significant difference was found between group A1 and group A2 (p > 0.05). Regarding the HeroShaper instrument, the results showed the highest TtF for group B3, with a statistically significant difference between the three subgroups B1, B2 and B3 (p < 0.05). The results showed that the torsional resistance increases as the angle of instrument access increases with a varying intensity, according to the crystallographic phase of the instrument selected. Full article

(This article belongs to the Special Issue Endodontics)

► Show Figures

Figure 1

10 pages, 5014 KiB

Open AccessFeature PaperArticle

Debunking the Concept of Dentinal Tubule Penetration of Endodontic Sealers: Sealer Staining with Rhodamine B Fluorescent Dye Is an Inadequate Method

by David Donnermeyer, Sina Schmidt, Arno Rohrbach, Johannes Berlandi, Sebastian Bürklein and Edgar Schäfer

Materials 2021, 14(12), 3211; https://doi.org/10.3390/ma14123211 - 10 Jun 2021

Cited by 19 | Viewed by 3153

Abstract

The aim of this study was to investigate the suitability of rhodamine B dye staining of an epoxy resin sealer (AH Plus) and calcium-silicate-based sealers (Total Fill BC Sealer, BioRoot RCS) to represent the penetration depth of the sealers into dentinal tubules after [...] Read more.

The aim of this study was to investigate the suitability of rhodamine B dye staining of an epoxy resin sealer (AH Plus) and calcium-silicate-based sealers (Total Fill BC Sealer, BioRoot RCS) to represent the penetration depth of the sealers into dentinal tubules after root canal obturation. In a three-step process, (1) leaching of rhodamine B from sealers into a buffer solution, (2) passive penetration of leached rhodamine B into dentinal tubules, and (3) conformity of rhodamine B penetration assessed by confocal laser scanning microscopy (CLSM), and sealer penetration assessed by scanning electron microscopy (SEM), in root-canal-filled teeth, were evaluated. Rhodamine B dye massively leached out of Total Fill BC Sealer and BioRoot RCS into the phosphate-buffered saline (PBS). A pinkish coloration of AH Plus was found after contact with PBS. Leached rhodamine B dye passively penetrated dentinal tubules from all three sealers when placed on root dentin. No correlation was observed between sealer penetration in SEM and rhodamine B penetration in CLSM. Staining of sealers using rhodamine B is an inadequate method with which to evaluate sealer penetration depth into dentinal tubules, as it overestimates the penetration of sealers into root dentin tubules. Full article

(This article belongs to the Special Issue Endodontics)

► Show Figures

Figure 1

9 pages, 730 KiB

Open AccessArticle

Apical Pressure Generated Using Conventional Syringe Irrigation in Immature Teeth—An In Vitro Study

by Marco Jäggi, Eva Magni, Florin Eggmann, Ashraf ElAyouti, Thomas Connert and Roland Weiger

Materials 2021, 14(10), 2580; https://doi.org/10.3390/ma14102580 - 15 May 2021

Cited by 4 | Viewed by 2197

Abstract

This in vitro study aimed to evaluate apical pressure during irrigant delivery with syringe irrigation in immature teeth with an open apical foramen. Conventional syringe irrigation was performed in a 3D-printed immature incisor. A 5 mL syringe combined with 25 G and 30 [...] Read more.

This in vitro study aimed to evaluate apical pressure during irrigant delivery with syringe irrigation in immature teeth with an open apical foramen. Conventional syringe irrigation was performed in a 3D-printed immature incisor. A 5 mL syringe combined with 25 G and 30 G cannulas was used. Open-ended and side-vented needle tip designs were assessed. Cannulas were placed at tooth length (TL), TL −1 mm, TL −2 mm, and TL −4 mm. The syringe plunger was moved with a force of 10 N, 20 N, 40 N, and 80 N to simulate clinical conditions. A pressure sensor measured periapical pressures during irrigation. Each experiment was repeated 10 times. Data were analyzed descriptively (maximum, mean, standard deviation, 95% CI) with the critical threshold indicative of extrusion set at 7.64 mbar. 30 G cannulas with both needle tip designs never exceeded the threshold at any TL with a plunger force of 10–40 N. At 80 N, 30 G open-ended cannulas exceeded the threshold in 10%, 30 G side-vented in 20–60% of the measurements. At any TL, 25 G open-ended cannulas and 25 G side-vented cannulas never crossed the threshold with forces of 10–20 N and 10 N, respectively. Consequently, 30 G cannulas with both designs can be recommended for irrigant delivery in immature teeth. 25 G cannulas ought to be used with caution. Full article

(This article belongs to the Special Issue Endodontics)

► Show Figures

Figure 1

11 pages, 5898 KiB

Open AccessArticle

Influence of 1-Hydroxyethylidene-1,1-Diphosphonic Acid on the Soft Tissue-Dissolving and Gelatinolytic Effect of Ultrasonically Activated Sodium Hypochlorite in Simulated Endodontic Environments

by Nidambur Vasudev Ballal, Anja Ivica, Pamela Meneses, Raj Kumar Narkedamalli, Thomas Attin and Matthias Zehnder

Materials 2021, 14(10), 2531; https://doi.org/10.3390/ma14102531 - 13 May 2021

Cited by 10 | Viewed by 3025

Abstract

The addition of Dual Rinse HEDP, an etidronate powder, to a sodium hypochlorite (NaOCl) solution can create a combined single endodontic irrigant with a soft tissue-dissolving and a decalcifying effect, which can replace traditional alternating irrigation with chemically non-compatible solutions. While the short-term [...] Read more.

The addition of Dual Rinse HEDP, an etidronate powder, to a sodium hypochlorite (NaOCl) solution can create a combined single endodontic irrigant with a soft tissue-dissolving and a decalcifying effect, which can replace traditional alternating irrigation with chemically non-compatible solutions. While the short-term compatibility between NaOCl and 1-hydroxyethylidene-1,1-diphosphonic acid (HEDP) has been shown, it remains unclear whether ultrasonic activation of a combined NaOCl & HEDP solution immediately reduces the available chlorine and/or renders the NaOCl ineffective in dissolving organic tissue remnants. This was tested in three experiments: (1) direct activation in test tubes in an ultrasonic bath and then the activation by an ultrasonically oscillating tip (IrriSafe) in (2) an epoxy resin model containing a simulated isthmus filled with gelatin, and (3) extracted teeth with simulated resorption cavities filled with soft tissue. The control solutions were physiological saline and 2.5% NaOCl without HEDP. In (1), available chlorine after 30 s of ultrasonic activation (37 kHz) of test and control solution was assessed, as well as shrimp tissue weight loss in direct exposure. In (2) and (3), the ultrasonic tip was driven at 1/3 of full power using the respective unit, and areas of removed gelatin from the isthmus and tissue weight loss were used as the outcomes, respectively. Experiment (1) revealed no negative impact by HEDP on available chlorine (1), while all three experiments showed a highly significant (p > 0.001) synergistic effect, which was not hampered by HEDP, between NaOCl and ultrasonic activation regarding tissue weight loss (1, 3) and dissolution of gelatin (2). Full article

(This article belongs to the Special Issue Endodontics)

► Show Figures

Figure 1

8 pages, 2050 KiB

Open AccessArticle

Evaluation of the Cyclic Fatigue of Two Single Files at Body and Room Temperature with Different Radii of Curvature

by Giusy Rita Maria La Rosa, Valeria Shumakova, Gaetano Isola, Francesco Indelicato, Calogero Bugea and Eugenio Pedullà

Materials 2021, 14(9), 2256; https://doi.org/10.3390/ma14092256 - 27 Apr 2021

Cited by 18 | Viewed by 2223

Abstract

Background: To compare the influence of different temperatures and curvature radii on the cyclic fatigue resistance of F6 SkyTaper (F6ST) and One Curve (OC) single file nickel-titanium rotary instruments. Methods: A total of 120 instruments of F6ST and OC #25.06 were evaluated in [...] Read more.

Background: To compare the influence of different temperatures and curvature radii on the cyclic fatigue resistance of F6 SkyTaper (F6ST) and One Curve (OC) single file nickel-titanium rotary instruments. Methods: A total of 120 instruments of F6ST and OC #25.06 were evaluated in 5 mm and 3 mm curvature radii at two temperatures (20 °C ± 1 °C and 37 °C ± 1 °C) in 16 mm stainless steel artificial canals associated with a curvature of 60°. The cyclic fatigue of tested files was assessed by employing a customized testing apparatus and expressed as times to fracture (TtF). A statistical analysis was performed with the significance level set at 95%. Results: All instruments decreased their TtF at 37 °C except for OC in the 3 mm radius, in which no significant difference was detected between 20 °C and 37 °C. A 3 mm curvature radius negatively affected TtF of all tested instruments, except for F6ST at 20 °C. F6ST had higher TtF than OC in the 3 mm radius at 20 °C, with no significant difference between them in the other tested conditions. Conclusions: Under the limits of the present in vitro study, body temperature impaired cyclic fatigue resistance of all files, except for OC in the 3 mm curvature radius. All instruments exhibited lower times to fracture in the 3 mm radius, excluding F6ST at 20 °C. Full article

(This article belongs to the Special Issue Endodontics)

► Show Figures

Figure 1

8 pages, 554 KiB

Open AccessArticle

Shaping Ability and Debris Extrusion of New Rotary Nickel-Titanium Root Canal Instruments

by Sebastian Bürklein, David Donnermeyer, Tim Julian Hentschel and Edgar Schäfer

Materials 2021, 14(5), 1063; https://doi.org/10.3390/ma14051063 - 24 Feb 2021

Cited by 5 | Viewed by 2312

Abstract

The aim was to evaluate the canal straightening and the amount of apically extruded debris associated with five rotary nickel-titanium when preparing curved root canals. A total of 100 root canals in extracted human teeth (angles of curvatures 20°–30°; radii 5.9–13.5 mm) were [...] Read more.

The aim was to evaluate the canal straightening and the amount of apically extruded debris associated with five rotary nickel-titanium when preparing curved root canals. A total of 100 root canals in extracted human teeth (angles of curvatures 20°–30°; radii 5.9–13.5 mm) were divided into five groups (n = 20/group). The groups were balanced with respect to the angle and the radius of canal curvature. The root canals were prepared using conventional austenite 55-NiTi alloy instruments F360, F6 SkyTaper (both Komet, Lemgo, Germany), and the heat-treated NiTi Jizai, Silk-Complex and Silk-Standard instruments (all Mani, Tochigi, Japan) to an apical size 25. The amount of extruded debris was assessed with a micro balance. Statistical analysis was performed using Kruskal–Wallis test with Bonferroni correction at a significance level of p < 0.05. During canal preparation, neither instrument fractures nor procedural preparation errors were noticed. Regarding canal straightening, the use of Jizai instruments resulted in the significantly lowest straightening (p < 0.05), while no significant differences were obtained between all other groups (p > 0.05). Regarding the amount of apically extruded debris, no significant differences between all groups were obtained (p > 0.05). Within the limitations of this study, all instruments performed well, and especially the Jizai instruments showed an excellent shaping ability. Full article

(This article belongs to the Special Issue Endodontics)

► Show Figures

Figure 1

11 pages, 2109 KiB

Open AccessArticle

Physico-Chemical Investigation of Endodontic Sealers Exposed to Simulated Intracanal Heat Application: Hydraulic Calcium Silicate-Based Sealers

by David Donnermeyer, Magdalena Ibing, Sebastian Bürklein, Iris Weber, Maximilian P. Reitze and Edgar Schäfer

Materials 2021, 14(4), 728; https://doi.org/10.3390/ma14040728 - 4 Feb 2021

Cited by 24 | Viewed by 2866

Abstract

The aim of this study was to gain information about the effect of thermal treatment of calcium silicate-based sealers. BioRoot RCS (BR), Total Fill BC Sealer (TFBC), and Total Fill BC Sealer HiFlow (TFHF) were exposed to thermal treatment at 37 °C, 47 [...] Read more.

The aim of this study was to gain information about the effect of thermal treatment of calcium silicate-based sealers. BioRoot RCS (BR), Total Fill BC Sealer (TFBC), and Total Fill BC Sealer HiFlow (TFHF) were exposed to thermal treatment at 37 °C, 47 °C, 57 °C, 67 °C, 77 °C, 87 °C and 97 °C for 30 s. Heat treatment at 97 °C was performed for 60 and 180 s to simulate inappropriate application of warm obturation techniques. Thereafter, specimens were cooled to 37 °C and physical properties (setting time/flow/film thickness according to ISO 6876) were evaluated. Chemical properties (Fourier-transform infrared spectroscopy) were assessed after incubation of the specimens in an incubator at 37 °C and 100% humidity for 8 weeks. Statistical analysis of physical properties was performed using the Kruskal-Wallis-Test (P = 0.05). The setting time, flow, and film thickness of TFBC and TFHF were not relevantly influenced by thermal treatment. Setting time of BR decreased slightly when temperature of heat application increased from 37 °C to 77 °C (P < 0.05). Further heat treatment of BR above 77 °C led to an immediate setting. FT-IR spectroscopy did not reveal any chemical changes for either sealers. Thermal treatment did not lead to any substantial chemical changes at all temperature levels, while physical properties of BR were compromised by heating. TFBC and TFHF can be considered suitable for warm obturation techniques. Full article

(This article belongs to the Special Issue Endodontics)

► Show Figures

Figure 1

Review

Jump to: Research, Other

10 pages, 1094 KiB

Open AccessReview

Torque Generation of the Endodontic Instruments: A Narrative Review

by Sang Won Kwak, Ya Shen, He Liu, Hyeon-Cheol Kim and Markus Haapasalo

Materials 2022, 15(2), 664; https://doi.org/10.3390/ma15020664 - 17 Jan 2022

Cited by 22 | Viewed by 4216

Abstract

As the use of nickel-titanium (NiTi) file systems for root canal therapy has become popular; hence, knowledge and understanding of the characteristics of NiTi files is essential for dentists. Unintended sudden fracture can occur during root canal shaping, and it is important to [...] Read more.

As the use of nickel-titanium (NiTi) file systems for root canal therapy has become popular; hence, knowledge and understanding of the characteristics of NiTi files is essential for dentists. Unintended sudden fracture can occur during root canal shaping, and it is important to understand the conditions that may cause instrument fractures. Torque is defined as the force required to rotate the NiTi file and can be considered of as a parameter for the stress generated. The endodontic engine maintains a constant rotational speed by adjusting torque regardless of the root canal conditions. The process of root canal shaping by rotary instruments is a series of actions that requires torque and generates stress to both the teeth and the NiTi instruments. The generated stress may induce the strain accumulation on NiTi instrument and the canal wall and lead to the development of microcrack in the instrument and dentinal wall. Therefore, understanding of torque and stress generated is important to prevent the fractures to the instrument and the teeth. This stress has been measured using various experimental approaches, including microcrack observation by using a microscope or computed tomography, attaching strain gauges to the teeth, and finite element analysis. This review focuses on the stress generated to the teeth and the instrument during instrumentation under various experimental conditions. The factors related to torque generation are also discussed. Full article

(This article belongs to the Special Issue Endodontics)

► Show Figures

Figure 1

12 pages, 2279 KiB

Open AccessReview

Antimicrobial and Antibiofilm Properties of Bioceramic Materials in Endodontics

by Zhejun Wang, Ya Shen and Markus Haapasalo

Materials 2021, 14(24), 7594; https://doi.org/10.3390/ma14247594 - 10 Dec 2021

Cited by 23 | Viewed by 5028

Abstract

Microbes are prevalent in the root canals of necrotic teeth, and they are the cause of primary and post-treatment apical periodontitis. Bacteria can dwell within the infected root canal system as surface-adherent biofilm structures, which exhibit high resistance to antimicrobial agents. Bioceramic materials, [...] Read more.

Microbes are prevalent in the root canals of necrotic teeth, and they are the cause of primary and post-treatment apical periodontitis. Bacteria can dwell within the infected root canal system as surface-adherent biofilm structures, which exhibit high resistance to antimicrobial agents. Bioceramic materials, with their biocompatible nature and excellent physico-chemical properties, have been widely used in dental applications, including endodontics. This review focuses on the application of bioceramic technology in endodontic disinfection and the antibiofilm effects of endodontic bioceramic materials. Different bioceramic materials have shown different levels of antibiofilm effects. New supplements have emerged to potentially enhance the antibiofilm properties of bioceramics aiming to achieve the goal of microbial elimination in the root canal system. Full article

(This article belongs to the Special Issue Endodontics)

► Show Figures

Figure 1

Other

Jump to: Research, Review

21 pages, 530 KiB

Open AccessSystematic Review

New Bioactive Calcium Silicate Cement Mineral Trioxide Aggregate Repair High Plasticity (MTA HP)—A Systematic Review

by Mirona Palczewska-Komsa, Kinga Kaczor-Wiankowska and Alicja Nowicka

Materials 2021, 14(16), 4573; https://doi.org/10.3390/ma14164573 - 14 Aug 2021

Cited by 15 | Viewed by 3671

Abstract

Bioactive calcium silicate cement Mineral Trioxide Aggregate (MTA) has been used for years as a gold standard in intravital pulp treatment and specialist endodontic procedures. Owing to flaws of the material, the manufacturers have been trying to enhance and produce materials showing improved [...] Read more.

Bioactive calcium silicate cement Mineral Trioxide Aggregate (MTA) has been used for years as a gold standard in intravital pulp treatment and specialist endodontic procedures. Owing to flaws of the material, the manufacturers have been trying to enhance and produce materials showing improved physical, chemical and biological parameters. One of the new calcium-silicate cements based on mineral trioxide aggregate, however without some flaws exhibited by the cement, is Mineral Trioxide Aggregate Repair High Plasticity (MTA HP). The aim of the present paper was a systematic literature review concerning the MTA HP material used nowadays in dentistry, as a review of its specific features. The present paper is the first article providing a systematic literature review on MTA HP. The aim of the present article is the better understanding of MTA HP properties, which can aid the decision-making process in endodontic treatment. Full article

(This article belongs to the Special Issue Endodontics)

► Show Figures

Figure 1

Journal Menu

Journal Browser

Endodontics

Share This Special Issue

Special Issue Editor

Special Issue Information

Keywords

Benefits of Publishing in a Special Issue

Published Papers (21 papers)

Research

Review

Other

Further Information

Guidelines

MDPI Initiatives

Follow MDPI