Effect of MTAD on Postoperative Discomfort: A Randomized Clinical Trial
Mahmoud Torabinejad, DMD, MSD, PhD, Shahrokh Shabahang, DDS, MS, PhD, and Khaled Bahjri, MD, MPH
The purpose of this study was to compare levels of postoperative discomfort after cleaning and shaping of root canals using two protocols for removal of smear layer. Seventy-three consecutive patients requiring root canal treatment were included. At random, canals were cleaned and shaped with one of the following protocols. In group 1, 5.25% sodium hypochlorite was used as the root canal irrigant. The smear layer was removed by placing 17% EDTA in the canal(s) for 1 min followed by a 5-ml rinse with 5.25% NaOCl. In group 2, canals were irrigated with 1.3% NaOCl; the smear layer was removed by placing MTAD in the canal(s) for 5 min. Access cavities were closed with a sterile cotton pellet and Cavit. The patients recorded degree of discomfort at various time intervals after cleaning and shaping on a visual analogue scale for 1 wk. No significant statistical difference was found in the degree of discomfort between the two groups (p = 0.58).
In Vivo Debridement Efficacy of Ultrasonic Irrigation Following Hand-Rotary Instrumentation in Human Mandibular Molars
Rubin Gutarts, DDS, MS, John Nusstein, DDS, MS, Al Reader, DDS, MS, and Mike Beck, DDS, MA
This study histologically compared the in vivo debridement efficacy of hand/rotary canal preparation versus a hand/rotary/ultrasound technique in mesial root canals of vital mandibular molars. Group 1 consisted of 16 teeth prepared with a hand/rotary technique whereas group 2 consisted of 15 teeth prepared in similar fashion but followed by 1 min of ultrasonic irrigation, per canal, utilizing an ultrasonic needle in a MiniEndo unit. Five uninstrumented mandibular molars served as histologic controls. After extraction and histologic preparation, 0.5 µm cross-sections, taken every 0.2 mm from the 1- to 3-mm apical levels, were evaluated for percentage of tissue removal. Nonparametric analysis revealed mean percent canal and isthmus cleanliness values to be significantly higher for group 2 at all levels evaluated, except one. In conclusion, the 1 min use of the ultrasonic needle after hand/rotary instrumentation resulted in significantly cleaner canals and isthmuses in the mesial roots of mandibular molars.
Adhesive Dentistry and Endodontics: Materials, Clinical Strategies and Procedures for Restoration of Access Cavities: A Review
Richard S. Schwartz, DDS, and Ron Fransman, DDS
The complexity of restorative dentistry has increased greatly in recent years, with the myriad of products used in “adhesive dentistry.” So too has the “simple” matter of restoring access cavities after completion of endodontic treatment. This review discusses current methods of “bonding” to tooth structure, ceramic materials, and metals, with emphasis on those aspects that are important to endodontics. Specific materials, procedures and major decision making elements are discussed, as well as how to avoid problems in compatibility between endodontic and restorative materials.
MTA Repair of a Supracrestal Perforation: A Case Report
Renato Menezes, DDS, MS, Ulisses Xavier da Silva Neto, DDS, MS, Everdan Carneiro, DDS, MS, Ariadne Letra, DDS, MS, Clóvis Monteiro Bramante, DDS, MS, PhD, and Norberti Bernadinelli, DDS, MS, PhD
Root perforations are undesired complications of endodontic treatment. In the recent literature, MTA has been regarded as an ideal material for perforation repair. This article describes a case report where an iatrogenic supracrestal perforation was repaired successfully with mineral trioxide aggregate (MTA).
Pulp Tissue Reactions to a Dentin Bonding Agent as a Direct Capping Agent
Ru¨stem Kemal Sübay, DDS, PhD, and Mustafa Demirci, DDS, PhD
The aim of this study was to investigate the response of human pulp tissue to a dentin bonding agent, Scotchbond Multi-Purpose Plus (SMPP), in exposed class V cavities. Sixteen human premolar teeth were mechanically exposed. Ten pulps were capped with SMPP and six teeth were capped with Dycal. The cavities were filled with a composite. After 40 days, the teeth were extracted and processed for histologic evaluation. Of the 10 teeth capped with SMPP, eight showed moderate chronic inflammation, one was severely inflamed, and one pulp had no to slight inflammation. None of the teeth capped with SMPP showed dentin bridge formation. Of the six teeth capped with Dycal, three exhibited incomplete dentin bridges associated with no to slight inflammation, and three showed no to slight inflammation, without formation of dentin bridges. Direct capping with Dycal with subsequent sealing with SMPP may show favorable results in pulp tissue. SMPP may cause inflammatory changes when applied directly to exposed pulp tissue.
Evaluation of the Flexural Strength of Carbon Fiber-, Quartz Fiber-, and Glass Fiber-Based Posts
Graziela Ávila Galhano, DDS, Luiz Felipe Valandro, DDS, MSc, Renata Marques de Melo, MD, DDS, Roberto Scotti, MD, DDS, and Marco Antonio Bottino, DDS, PhD
This study investigated the flexural strength of eight fiber posts (one carbon fiber, one carbon/quartz fiber, one opaque quartz fiber, two translucent quartz fiber, and three glass fiber posts). Eighty fiber posts were used and divided into eight groups ( n = 10): G1: C-POST (Bisco); G2: ÆSTHETI-POST (Bisco); G3: ÆSTHETI- PLUS (Bisco); G4: LIGHT-POST (Bisco); G5: D.T. LIGHT-POST (Bisco); G6: PARAPOST WHITE (Coltene); G7: FIBERKOR (Pentron); G8: REFORPOST (Angelus). All of the samples were tested using the three-point bending test. The averages obtained were submitted to the ANOVA and to Tukey’s test (p < 0.05). The mean values (MPa) of the groups ÆSTHETI-POST—carbon/quartz fiber post (Bisco) and ÆSTHETI-PLUS—quartz fiber post (Bisco) were statistically similar and higher than the mean values of the other groups. The mean values of the groups C-POST—carbon fiber post (Bisco), LIGHT-POST—translucent quartz fiber post (Bisco), D.T. LIGHT-POST—double tapered translucent quartz fiber post (Bisco), PARAPOST WHITE—glass fiber post (Coltene) and FIBREKOR—-glass fiber post (Pentron) were similar and higher than the group REFORPOST— glass fiber post (Angelus).
An In Vitro Comparison of the Sealing Ability of Three Endodontic Sealers Used in Canals with Iatrogenic Enlargement of the Apical Constriction
Christos Dandakis, DDS, Mary Kaliva, DDS, Theodoros Lambrianidis, PhD, DDS, and Eleni Kosti, DDS
In cases of disrupted apical constriction effort is made to create an apical stop and subsequently instrument and obturate the canal up to this point. The aim of this study was to in vitro evaluate the sealing ability of three root canal sealers used with the lateral compaction technique in teeth with enlarged constriction. Thirty- six single rooted premolars with straight canals were instrumented up to the apical constriction using a stepback technique. The constriction was enlarged and root canal instrumentation 1.5 mm short of the original working length was performed, to create a new apical stop. Teeth were obturated using lateral compaction technique with either Topseal, Roth 811, or Apexit. Teeth were subjected to area-metric analysis of dye penetration in transverse root sections, up to the most coronal extend of the dye. Sections were studied under the stereomicroscope, digital images were processed and leakage area was estimated. Statistical analysis was performed using Student’s t test and Wilcoxon matched-pairs signed-rank test. No gutta-percha was extruded into the space between the apical constriction and the new iatrogenically created constriction. Topseal showed statistical significant less leakage. No significant difference was found between Apexit and Roth 811 ( t = 0.99; p = 0.75).
Preferential Attachment of Human Gingival Fibroblasts to the Resin Ionomer Geristore
Fuwad Al-Sabek, DDS, MS, Sandra Shostad, DDS, MS, and Keith L. Kirkwood, DDS, PhD
The resin ionomer Geristore has been used extensively for root perforation repairs. The purpose of this study was to evaluate oral in vitro biocompatibility of the resin ionomer Geristore compared to two other dental perforation repair materials, Ketac-Fil and Immediate Restorative Material (IRM). Growth and morphology of human gingival fibroblasts (HGFs) was determined using scanning electron microscopy (SEM) of HGFs cells grown on test materials as well as cytotoxicity assays using eluates from test materials. SEM analysis showed that HGFs attached and spread well over Geristore with relatively normal morphology. SEM showed that fibroblasts did not attach and spread well over Ketac-Fil or IRM as cells appeared much fewer with rounded and different morphology than fibroblasts grown on Geristore. Cytotoxicity assays indicated that HGFs proliferated in the presence of Geristore eluates and not in the presence of Ketac-Fil or IRM eluates. In vitro interpretation indicates that Geristore is less cytotoxic to gingival fibroblasts.
The Effect of the Distance Between Post and Residual Gutta-Percha on the Clinical Outcome of Endodontic Treatment
Joshua Moshonov, DMD, Iris Slutzky-Goldberg, DMD, Ayelet Gottlieb, DMD, and Benny Peretz, DMD
To determine whether the distance between the post and the residual gutta-percha influences the clinical outcome of endodontic treatment, 94 endodontically treated teeth following post and core restoration were evaluated radiographically. The teeth were divided into three groups: (I) no gap between the gutta-percha and the post; (II) a gap of >0 to 2 mm; (III) a gap of >2 mm. Treatment outcome was evaluated in follow-up radiographs, taken 1 yr after treatment and up to 5 yr posttreatment. In group I, 83.3% of the teeth were evaluated normal, 53.6% of group II, and only 29.4% of group III. A gap between the gutta-percha and the post was related to an increased rate of emerged disease in endodontically treated teeth restored with a post and core.
Vasorelaxant Effect of Resin-Based, Single-Bottle Dentin Bonding Systems
Worku Abebe, PhD, David H. Pashley, DMD, PhD, and Fred A. Rueggeberg, DDS, MS
Single-bottle dentin bonding systems are currently in wide use. Because these materials are sometimes Inadvertently placed on microscopic pulp exposures while at other times deliberately on frank exposures, their effects on pulpal soft tissues need to be evaluated. The present study assessed the vascular effects of 3M Single Bond (3MSB) and Prime & Bond NT (PBNT), using rat aortic ring preparations. It is hypothesized that these bonding agents induce relaxation of these preparations. Both 3MSB and PBNT caused endothelium-dependent and -independent relaxations in a concentration-dependent manner. The endothelium-dependent relaxation was associated with the release of nitric oxide. However, the responses to both agents did not involve the generation of prostanoids or KATP channel activation. At relatively low concentrations, the responses of endothelium-denuded tissues to 3MSB were greater than those to PBNT, indicating certain differences in the vascular action between these products. The data suggest that 3MSB and PBNT interfere with vascular function by causing vasorelaxation via mechanisms occurring in the smooth muscle and endothelium, including the release of nitric oxide. Among others, this effect may promote bleeding if these adhesives are placed on pulp exposures.
Comparison of Generated Forces and Apical Microleakage Using Nickel-Titanium and Stainless Steel Finger Spreaders in Curved Canals
Saman R. Gharai, DDS, MS, Jeffrey R. Thorpe, DDS, James M. Strother, DDS, MS, and Scott B. McClanahan, DDS, MS
The purpose of this study was to compare (a) forces generated during lateral compaction and (b) apical microleakage for nickel-titanium (NiTi) and stainless steel (SS) finger spreaders. Twenty-eight extracted human teeth were instrumented using a standardized rotary instrumentation technique. NiTi and SS #30 spreaders were used to obturate molar roots while the forces generated during obturation were measured on a Universal testing machine. Apical microleakage was determined using a fluid filtration method. There was no significant difference in microleakage between spreaders. NiTi spreaders produced significantly less force than SS spreaders in all specimens (p < 0.001).
Effect of Cyclic Fatigue on Static Fracture Loads in ProTaper Nickel-Titanium Rotary Instruments
Cheryl J. Ullmann, cand med dent, Ove A. Peters, PD, Dr med dent, MS FICD
The aim of the present study was to evaluate static fracture loads of ProTaper Nickel-Titanium instruments that had been subjected to various degrees of cyclic fatigue. Torque and angle at failure of new instruments and instruments that had been stressed to 30, 60, or 90% of their cyclic fatigue rotations in a simulated canal (90° and 5 mm radius) were tested according to ISO 3630-1. With unused ProTaper instruments, resistance to cyclic fatigue decreased with diameter increase and ranged from 158 to 450 rotations. Torque at failure ranged from 0.5 to 2.1 Ncm and showed a strong linear relationship to instrument diameter ( r² = 0.9) while angle at failure was weakly related to diameter ( r² = 0.46). Cyclic prestressing significantly reduced torsional resistance in finishing files, while shaping files were largely unaffected. In conclusion, build-up of tension within NiTi rotary instruments depends on instrument diameter. Clinically, larger instruments that have been subjected to some cyclic fatigue should be used with great care or discarded.
Effects of Endodontic Irrigation Solutions on Mineral Content of Root Canal Dentin Using ICP-AES Technique
Hale Ari and Ali Erdemir
The aim of this in vitro study was to evaluate mineral content of root canal dentin after treatment with several endodontic irrigation solutions. Sixty mandibular anterior teeth extracted for periodontal reasons used. The crowns of the teeth were removed at the cementoenamel junction. Pulp tissues were removed and the teeth were randomly divided into six groups including 10 teeth each. Root canals were enlarged with gatesglidden burs (# 1, 2, and 3). The groups were treated as follows: group 1, 0.2% chlorhexidine gluconate for 15 min; group 2, 3% H₂O₂ for 15 min; group 3, 17% EDTA for 15 min; group 4, 5.25% NaOCl for 15 min; group 5, 2.5% NaOCl for 15 min; and group 6, distilled water (control). Dentin chips were obtained using gates-glidden burs (# 4, 5, and 6). The levels of five elements calcium, phosphorus, magnesium, potassium, and sulfur in each specimens were analyzed using ICP-AES (Inductively Coupled Plasma Atomic Emission Spectrometry) technique. Changes in the levels of the chemical elements were recorded. The results were then statistically analyzed by one-way ANOVA and Tukey tests. There was a significant decrease in the calcium and phosphorus levels after treatment with all irrigation solutions except for 5.25% NaOCl when compared with the control group (p < 0.05). The K, Mg, and S level changes were not statistically significant (p > 0.05). It has been concluded that endodontic irrigation solutions have an effect on mineral contents of root dentin.
MTA Repair of a Supracrestal Perforation: A Case Report
Renato Menezes, DDS, MS, Ulisses Xavier da Silva Neto, DDS, MS,Everdan Carneiro, DDS, MS, Ariadne Letra, DDS, MS,Clóvis Monteiro Bramante, DDS, MS, PhD, and Norberti Bernadinelli, DDS, MS, PhD
Root perforations are undesired complications of endodontic treatment. In the recent literature, MTA has been regarded as an ideal material for perforation repair. This article describes a case report where an iatrogenic supracrestal perforation was repaired successfully with mineral trioxide aggregate (MTA).