Effect of Premedication on the Success of Inferior Alveolar Nerve Block in Patients with Irreversible Pulpitis: A Systematic Review of the Literature.

BACKGROUND: Failure in the provision of inferior alveolar nerve block anesthesia (IANB) is a significant problem during endodontic treatment of irreversible pulpitis. Various methodologies have been advocated one of which is administration of premedication prior to anesthesia. Despite the considerable number of reports, the topic yet deserves more clarification. This systematic review was conducted to provide an oversight on the effectiveness of premedication prior to IANB in mandibular teeth. METHODS: A PubMed and Cochrane Database search was conducted by using MeSH terms inferior alveolar nerve block + pulpitis and mandibular anesthesia+pulpitis. Two reviewers independently performed the screening, selection of papers, and data extraction. Papers in English language that included randomized clinical studies on the impact of different medications on the success of inferior alveolar block anesthesia in irreversible pulpitis were included. Additionally, relevant supporting literature was also used where necessary. RESULTS: Initially, 118 papers were selected from PubMed and 68 were selected from Cochrane. Five additional articles were retrieved from Google Search. Following the elimination of duplicates and irrelevant articles, 35 studies were selected meeting the criteria. It was observed that there was moderate evidence to suggest that some premedications were partially effective for the enhancement of mandibular anesthetic effect in irreversible pulpitis. CONCLUSION: Though some medications appear to be promising, further supporting research will help highlight this significant topic which requires further clarification.

Fracture resistance of simulated immature tooth roots reinforced with MTA or restorative materials.

BACKGROUND/AIM: Immature endodontically treated teeth may require reinforcing to reduce the risk of root fracture. This study assessed the fracture resistance of simulated immature tooth roots reinforced with mineral trioxide aggregate (MTA) or two composite resin (CR) materials. MATERIAL AND METHODS: One hundred extracted roots of mature human maxillary incisors were decoronated and sectioned 9 mm further apically from the decoronation line and randomly divided into five groups (n = 20). In Group 1 (negative control), roots received no treatment. In groups 2-5, canals were enlarged to 2.1 mm diameter to simulate immature roots, dressed with calcium hydroxide (Ca(OH)2 ) and incubated for 7 days. After removal of Ca(OH)2 , canals in Group 2 (positive control) were left unfilled. Canals in groups 3, 4 and 5 were filled with MTA, BisFil 2B flowable CR or BisFil II posterior CR, respectively. After further incubation for 30 days, specimens were embedded in acrylic cylinders and horizontally loaded in a universal testing machine at cross head speed of 5 mm min(-1) until fracture occurred. Load (N) at and pattern of fracture were recorded. RESULTS: Load at fracture was significantly lower (t-test, P = 0.003) in Group 2 (630 ± 199.12) than in Group 1 (896.98 ± 311.79). It did not differ significantly among groups 1, 3, 4 and 5 (anova, P > 0.07). Pattern of fracture did not differ among the groups either. CONCLUSION: Within the limitations of this study, root canal filling with MTA and two CR materials affected reinforcement of simulated immature roots to levels comparable with intact roots.

In Vitro Evaluation of ProRoot MTA, Biodentine, and MM-MTA on Human Alveolar Bone Marrow Stem Cells in Terms of Biocompatibility and Mineralization.

INTRODUCTION: Stem cell technology has been a great hope for the regeneration of cells of pulp-dentin complex and dental structures together with surrounding bone and periodontium. The main challenge in the regeneration process is a successful combination of stem cells and efficient inductors such as inductive biomaterials. In this regard, today, manufacturers propose novel tooth filling materials. The current study was aimed to compare the effect of ProRoot MTA (Dentsply Tulsa Dental, Tulsa, OK), Biodentine (Septodont, Saint Maur des Fossés, France), and MM-MTA (Micro-Mega, Besançon Cedex, France) on the cell viability, hard tissue deposition capacity, and osteogenic differentiation of human bone marrow stem cells (hBMSCs) derived from mandibular bone. METHODS: Dental materials were packed into Teflon rings (Grover Corp, Milwaukee, WI) and placed on Transwell inserts (Corning, Corning, NY) to determine the toxicity of tooth filling materials by the 3-(4,5-dimethyl-thiazol-2-yl)-5-(3-carboxy-methoxy-phenyl)-2-(4-sulfo-phenyl)-2H tetrazolium assay on days 1, 3, 7, and 14; 20% dimethyl sulfoxide (DMSO) was used as a positive control for the toxicity assay. hBMSCs were characterized by their surface markers with mesenchymal stem cell antibodies. Teflon rings were cocultured with hBMSCs followed by the induction of osteogenic differentiation. The osteogenic differentiation of hBMSCs and hard tissue formation of the materials were evaluated by analyzing the messenger RNA expression levels of osteonectin, Runt-related transcription factor 2, and collagen type 1A by real-time polymerase chain reaction expression analysis, measurement of alkaline phosphatase activity, and visualization of calcium deposits by alizarin red staining. RESULTS: MTA, Biodentine, and MM-MTA did not exhibit a cytotoxic effect on hBMSCs after 14 days in culture. Even though all the materials significantly stimulate (P < .05) osteogenic differentiation of hBMSCs compared with the negative control, ProRoot MTA showed greater osteoinductivity than Biodentine or MM-MTA according to the messenger RNA expression, alkaline phosphatase, immunocytochemistry, and alizarin red staining data. CONCLUSIONS: All of the dental materials used in this study show the osteogenic differentiation potential of hBMSCs. Therefore, newly introduced MM-MTA can also be used as a material of choice in routine dental treatment.

Inadvertent apical extrusion of sodium hypochlorite with evaluation by dental volumetric tomography.

This case report describes the tissue injury caused by inadvertently extruded NaOCl through the apical constriction. A 56-year-old female patient with complaints of pain, swelling, and ecchymosis on the left side of her face was referred to our clinic. The symptoms had emerged following root canal treatment of the maxillary left first premolar, and a soft tissue complication due to apical extrusion of NaOCl was diagnosed. Antibiotics and analgesics were prescribed. DVT images revealed that the buccal root apex had perforated the maxillary bone. The patient was followed up every other day and became asymptomatic on the 10th day. Endodontic therapy was completed with routine procedures. Determining working length precisely and following irrigation protocols meticulously are indispensable to prevent this type of complication. 3D visualization of the affected area may reveal the cause of the incident.

A review on biodentine, a contemporary dentine replacement and repair material.

Biodentine is a calcium-silicate based material that has drawn attention in recent years and has been advocated to be used in various clinical applications, such as root perforations, apexification, resorptions, retrograde fillings, pulp capping procedures, and dentine replacement. There has been considerable research performed on this material since its launching; however, there is scarce number of review articles that collates information and data obtained from these studies. Therefore, this review article was prepared to provide the reader with a general picture regarding the findings about various characteristics of the material. The results of a PubMed search were classified and presented along with some critical comments where necessary. The review initially focuses on various physical properties of the material with subheadings and continues with biocompatibility. Another section includes the review of studies on Biodentine as a vital pulp treatment material and the article is finalized with the summary of some case reports where the material has been used.

Comparison of the radiopacities of different root-end filling and repair materials.

This study evaluated the radiopacity of 3 repair materials, Biodentine, MM-MTA, and MTA Angelus. Standardized cylindrical rings were prepared. Samples of Biodentine MM-MTA and MTA Angelus were prepared (n = 10 in each group), filled into the rings, and preserved at 37°C until setting. A 1 mm thick dentin slice was used as control. All set specimens were removed and radiographed along with the dentine slice and a graduated aluminium step wedge. Digital images were transferred to the computer using a software. The radiographic densities of the specimens were determined, and the values were converted into millimetres of aluminium (mm Al). One-way ANOVA was used for intergroup comparison, whereas Tukey HSD test was used for detecting the group with the difference. The mean radiopacities of Biodentine, MTA Angelus, and MM-MTA were 2.8 ± 0.48, 4.72 ± 0.45, and 5.18 ± 0.51 mm Al, respectively. The radiopacity of Biodentine was significantly lower compared to other materials (P = 0.001), whereas no significant difference was noted between MTA Angelus and MM-MTA (P = 0.109). All materials had significantly higher radiopacities compared to dentine. The relatively lower radiopacity of Biodentine can be improved to achieve more reliable results in procedures such as retrograde fillings.

The status of mineral trioxide aggregate in endodontics education in dental schools in Turkey.

The aim of this study was to assess the current status of mineral trioxide aggregate (MTA) as an educational material in dental schools in Turkey. A survey was sent to senior members of the endodontic departments of seventeen dental schools; fourteen responded. All respondents reported that they used MTA in their clinical practice, with apexification, perforations, retrograde fillings, and root resorptions being the most frequently occurring treatment procedures. All reported that information was given to students regarding MTA mainly as part of the curriculum. The third and fourth years were the periods when MTA was introduced to students in most of the schools. Twelve schools reported that students had the opportunity to observe procedures in which MTA was used, but students had the chance to use the material in a very minor proportion of the schools, mainly under the supervision of clinical instructors. Ten schools agreed that MTA should be included in the regular endodontic curriculum. Financial constraints seemed to be the predominant reason for those who answered this question negatively, followed by difficult handling properties and low radiopacity of the material. Within the limitations of this study, it can be concluded that ways should be sought to prevent financial difficulties from depriving dental students of the opportunity to receive information about contemporary methodologies such as MTA utilization.

Potential of an Er:YAG laser in the removal of calcium hydroxide from root canals.

OBJECTIVE: The purpose of this study was to assess the calcium hydroxide (CH) removal potential of an Er:YAG laser in combination with ethylenediaminetetraacetic acid (EDTA) and sodium hypochlorite (NaOCl) irrigation. BACKGROUND DATA: Removal of the CH dressing prior to the root canal filling is mandatory, as its remnants may mechanically block the apical area of the root canal system and also have an effect on the texture, viscosity, working time, penetration, and adhesion of root canal sealers. However, the removal of CH from the canal space is challenging, because it should ideally be placed deep and densely, so that its biological effects can be exerted in close proximity to the appropriate tissues. METHODS: In this study, the mandibular premolar teeth were embedded in acrylic blocks and sectioned longitudinally through the canal, forming two halves following shaping of the root canals with ProTaper (Maillefer, Ballaigues, Switzerland) rotary instruments. The teeth were reassembled after standard grooves created onto canal walls were filled with CH. In group 1, conventional irrigation was performed with 10 mL of 17% EDTA and 10 mL of 5% NaOCl, and in goup 2, Er:YAG laser following conventional irrigation was performed. Images of the grooves taken before and after irrigation were scored and the Mann-Whitney U test was used to statistically evaluate the results. RESULTS: The percentage of CH score reduction was 46.30% in group 1 and 60.58% in group 2. No significant difference was found between two groups (p>0.05). CONCLUSIONS: The laser did not improve the removal of CH during conventional root canal irrigation performed with NaOCl and EDTA under the conditions of current study.

The operating microscope enhances detection and negotiation of accessory mesial canals in mandibular molars.

INTRODUCTION: Detection and negotiation of accessory mesial canals in mandibular molars was investigated with the aid of magnifying loupes or the operating microscope. METHODS: First and second mandibular molars (n = 96) were mounted in mannequins. Three independent investigators (endodontists) prepared access cavities using 4.5x loupes, attempting to detect and negotiate accessory mesial canals with ultrasonic instruments. If detection or negotiation was unsuccessful, the procedure was continued using the microscope. The location of accessory mesial canals was mapped in relation to the main mesial canals, and their pathway shown with inserted files. The mesial roots were cross-sectioned at three levels to inspect for nonnegotiated accessory mesial canals. RESULTS: With the microscope, the number of detected accessory mesial canals increased from 8 (16%) to 9 (18%) in first molars and from 8 (16%) to 11 (22%) in second molars. Negotiated accessory mesial canals increased from 6 (12%) to 7 (14%) and from 5 (10%) to 9 (18%) in the first and second molars, respectively. All 20 detected accessory mesial canals were located in the mesial subpulpal groove, closer to the mesiolingual canal (45%), in the middle (30%), or closer to the mesiobuccal canal (25%). All negotiated accessory mesial canals merged with one of the main two canals. Cross-sections of the roots confirmed that no accessory canals were present in addition to those negotiated. CONCLUSIONS: Within the limitations of this study, more accessory canals were detected and negotiated when using the microscope compared with loupes. This improvement was more pronounced in second molars than in first molars. All negotiated accessory canals merged with either one of the main mesial canals.

Microleakage of various root filling systems by glucose filtration analysis.

OBJECTIVE: The aim of this study was to evaluate the microleakage of Resilon + Epiphany, EndoRez, Activ GP, and conventional AH Plus + gutta-percha technique using the glucose filtration model. STUDY DESIGN: One hundred twenty maxillary incisors were divided into 5 experimental and 2 control groups. After root canal shaping, the experimental groups were filled with AH Plus + gutta-percha (lateral compaction), Resilon + Epiphany (lateral compaction), AH Plus + Protaper's proprietory cone, EndoRez + sealer, or Activ GP + sealer). The specimens were mounted on a glucose model and samples were taken for 3 weeks for leakage measurement. RESULTS: No statistically significant difference was observed between the leakage of all groups at the 3 testing periods (P > .05). CONCLUSION: The filling materials with the monoblock concept do not seem to be superior to the conventional AH Plus + gutta-percha system regarding microleakage.