Effect of two different concentrations of sodium hypochlorite on postoperative pain following single-visit root canal treatment: a triple-blind randomized clinical trial.

AIM: To compare the effects of two different concentrations of NaOCl solution on postoperative pain following single-visit root canal treatment in mandibular molars with irreversible pulpitis. METHODOLOGY: A total of 122 patients who had mandibular molars with irreversible pulpitis were treated. The patients were randomly divided into two groups according to the concentration of NaOCl used during root canal instrumentation - either 2.5% or 5.25%. RaCe rotary instruments were used for root canal preparation, and all root canals were filled in one visit. Postoperative pain was evaluated using the visual analogue scale. Data were analysed by independent t-test, chi-square and Mann-Whitney tests. RESULTS: Twelve patients were excluded for various reasons. Pain reported by 110 patients who were eligible to be included in the study was analysed. No significant differences were found in the age and gender of the patients between the two groups (P = 0.50, P = 0.51, respectively). The patients who had 5.25% NaOCl reported significantly lower postoperative pain compared to those who had 2.5% NaOCl during the first 72 h following treatment (P = 0.021); however, there was no significant difference in pain felt by the patients during the rest of the study period, that is 4-7 days following treatment (P = 0.185) when the four-level pain categorization method was used. When the two-level pain categorization method was used, the results revealed that patients who had 5.25% NaOCl reported significantly less pain for the first 3 days after treatment (P = 0.026). The number of analgesics taken by patients who had 2.5% NaOCl was significantly higher than that taken by patients who had 5.25% NaOCl (P = 0.001). CONCLUSION: 5.25% NaOCl was associated with significantly lower postoperative pain compared to 2.5% NaOCl during the first 72 h following one-visit root canal treatment of mandibular molars with irreversible pulpitis.

Mineral trioxide aggregate and other bioactive endodontic cements: an updated overview - part II: other clinical applications and complications.

Mineral trioxide aggregate (MTA) is a dental material used extensively for vital pulp therapies (VPT), protecting scaffolds during regenerative endodontic procedures, apical barriers in teeth with necrotic pulps and open apices, perforation repairs as well as root canal filling and root-end filling during surgical endodontics. A number of bioactive endodontic cements (BECs) have recently been introduced to the market. Most of these materials have calcium and silicate in their compositions; however, bioactivity is a common property of these cements. These materials include the following: BioAggregate, Biodentine, BioRoot RCS, calcium-enriched mixture cement, Endo-CPM, Endocem, EndoSequence, EndoBinder, EndoSeal MTA, iRoot, MicroMega MTA, MTA Bio, MTA Fillapex, MTA Plus, Neo MTA Plus, Ortho MTA, Quick-Set, Retro MTA, Tech Biosealer, and TheraCal LC. It has been claimed that these materials have properties similar to those of MTA but without the drawbacks. In Part I of this review, the available information on the chemical composition of the materials listed above was reviewed and their applications for VPT was discussed. In this article, the clinical applications of MTA and other BECs will be reviewed for apexification, regenerative endodontics, perforation repair, root canal filling, root-end filling, restorative procedures, periodontal defects and treatment of vertical and horizontal root fractures. In addition, the literature regarding the possible drawbacks of these materials following their clinical applications is reviewed. These drawbacks include their discolouration potential, systemic effects and retreatability following use as a root filling material. Based on selected keywords, all publications were searched regarding the use of MTA as well as BECs for the relevant clinical applications. Numerous publications were found regarding the use of BECs for various endodontic applications. The majority of these investigations compared BECs with MTA. Despite promising results for some materials, the number of publications using BECs for various clinical applications was limited. Furthermore, most studies had several methodological shortcomings and low levels of evidence.

Mineral trioxide aggregate and other bioactive endodontic cements: an updated overview - part I: vital pulp therapy.

Mineral trioxide aggregate (MTA) is a bioactive endodontic cement (BEC) mainly comprised of calcium and silicate elements. The cement was introduced by Torabinejad in the 1990s and has been approved by the Food and Drug Administration to be used in the United States in 1997. A number of new BECs have also been introduced to the market, including BioAggregate, Biodentine, BioRoot RCS, calcium-enriched mixture cement, Endo-CPM, Endocem, EndoSequence, EndoBinder, EndoSeal MTA, iRoot, MicroMega MTA, MTA Bio, MTA Fillapex, MTA Plus, NeoMTA Plus, OrthoMTA, Quick-Set, RetroMTA, Tech Biosealer and TheraCal LC. It has been claimed that these materials have properties similar to those of MTA without its drawbacks. In this article, the chemical composition and the application of MTA and other BECs for vital pulp therapy (VPT), including indirect pulp cap, direct pulp cap, partial pulpotomy, pulpotomy and partial pulpectomy, have been reviewed and compared. Based on selected keywords, all papers regarding chemical composition and VPT applications of BECs had been reviewed. Most of the materials had calcium and silicate in their composition. Instead of referring to the cements based on their chemical compositions, we suggest the term 'bioactive endodontic cements (BECs)', which seems more appropriate for these materials because, in spite of differences in their chemical compositions, bioactivity is a common property for all of them. Numerous articles were found regarding use of BECs as VPT agents for indirect and direct pulp capping, partial pulpotomy and cervical pulpotomy. Most of these investigations used MTA for VPT. In most studies, newly introduced materials have been compared to MTA. Some of the BECs have shown promising results; however, the number of their studies compared to investigations on MTA is limited. Most studies had several methodological shortcomings. Future investigations with rigorous methods and materials are needed.

Efficacy of supplementary buccal infiltrations and intraligamentary injections to inferior alveolar nerve blocks in mandibular first molars with asymptomatic irreversible pulpitis: a randomized controlled trial.

AIM: This randomized double-blinded controlled trial was performed to compare the efficacy of inferior alveolar nerve block (IANB) injection for mandibular first molar teeth with irreversible pulpitis with or without supplementary buccal infiltration and intraligamentary injection. METHODOLOGY: Eighty-two patients with asymptomatic irreversible pulpitis received either a combination of intraligamentary injection + buccal infiltration+ IANB or with traditional IANB injection in mandibular first molar teeth with irreversible pulpitis. Each patient recorded their pain score on a Heft-Parker visual analogue scale before commencing treatment, in response to a cold test 15 min after the designated anaesthetic injection, during access cavity preparation and during root canal instrumentation. No or mild pain at any stage was considered a success. Data were analysed by chi-square test. RESULTS: At the final stage of treatment, 69 of the 82 patients were eligible to be included in the study. No significant difference was found between age (P = 0.569) and gender (P = 0.570) amongst the patients in the two groups. The success rate of anaesthesia in the IANB and the combination groups were 22% and 58%, respectively. The success rate of anaesthesia in the combination group was significantly higher than the traditional IANB injection (P = 0.003). CONCLUSION: A combination of anaesthetic techniques can improve the success rate of anaesthesia for mandibular first molar teeth with irreversible pulpitis.

Comparative study of subcutaneous tissue responses to a novel root-end filling material and white and grey mineral trioxide aggregate.

AIM: To compare the subcutaneous tissue response to grey mineral trioxide aggregate (GMTA), white mineral trioxide aggregate (WMTA) and a new experimental cement (calcium enriched cement, CEM). METHODOLOGY: Thirty-six Wistar male albino rats each received three implants, containing one of the tested materials, and an empty tube as a control. Seven, 30 and 60 days after implantation, the animals were sacrificed. After histological preparation and H&E staining, the specimens were evaluated for capsule thickness, necrosis, and for the type, the severity, and the extent of inflammation. Kruskal Wallis and Chi-square tests were used for data analysis. RESULTS: After 1 week, CEM produced no necrosis compared to both types of WMTA and GMTA (P = 0.007). After 30 days, GMTA specimens had significantly less inflammation compared with WMTA and CEM (P = 0.011). After 60 days, less inflammation was associated with CEM specimens (P = 0.0001) compared to the other materials. Dystrophic calcifications in the connective tissue adjacent to all experimental material were detected. CONCLUSION: Histological observation illustrated that all materials were well tolerated by the subcutaneous tissues.

Comparison of dentine removal using V-taper and K-Flexofile instruments.

AIM: To compare the dentine removal ability of V-Taper and K-Flexofile instruments in mesiobuccal canals of extracted mandibular first molar teeth. METHODOLOGY: Preoperative images of 40 mesiobuccal canals of mandibular first molars (with a curvature between 20° and 35°) were obtained at 2, 4.5, and 7 mm from the root apices by CT-scan and divided into two groups. Group F was prepared with K-Flexofiles and Gates Glidden drills and Group V with V-Taper Ni-Ti rotary and stainless steel hand instruments. Post-instrumentation images were then obtained and compared with the preoperative images. The ratio of dentine removal based on pre- and postoperative images was calculated, and data was analysed by anova and Tukey post hoc test. RESULTS: In group F in the coronal sections, the least ratio of the dentine removal to the initial root thickness was on the buccal aspect (15.14% ± 6.72), and the greatest ratio was found on the distolingual (29.38% ± 8.19). In group V in the coronal, the least ratio of the dentine removal to the initial root thickness was on the buccal aspect (9.81% ± 3.26); the greatest ratio was found on the distolingual surface in the coronal sections (34.38% ± 10.51). In the middle sections, the least ratio was on the buccal (10.51% ± 3.39) and the greatest on the distolingual aspects (27.46% ± 12.34) of the roots. In the apical sections, the amount of the dentine removed from the mesial and distal surfaces in group V was significantly more than group F (P < 0.01). CONCLUSION: The distolingual aspect of the root canal is a danger zone for the mesiobuccal canal of the mesial root in mandibular molar teeth, and preparation of that area should be performed with caution. Except the apical part of the canal, no significant difference was found between the two preparation files or techniques used. Apart from the apical part of the canal, neither instrument maintained the original shape of the coronal and middle parts of the canal.

A comparative study of dental pulp response to several pulpotomy agents.

AIM: To examine the in vivo response of dental pulps in dogs to three pulp-capping agents: calcium hydroxide (CH), mineral trioxide aggregate (MTA) and a new endodontic calcium enriched mixture (CEM) cement. METHODOLOGY: Thirty-six second and third premolar teeth in six beagle dogs were randomly assigned to three experimental groups; CH, MTA or CEM cement. Following isolation and exposure, pulp tissues were removed with a fissure bur and haemostasis achieved. The pulps were dressed with appropriate materials, and the access cavity restored with amalgam. Histological analysis was performed 8 weeks after treatment; the samples were assessed by an independent observer for calcified bridge formation, pulp vitality and pulp inflammation. The data were analysed by Kruskal-Wallis, Mann-Whitney and one-way anova tests. RESULTS: The number of root canals that showed calcified bridge formation, pulp vitality and lack of inflammation was significantly higher for teeth capped with either MTA or CEM cement in comparison with CH (P < 0.05). No significant difference was found between the CEM cement and MTA in terms of calcified bridge formation, pulp vitality and lack of inflammation (P > 0.05). CONCLUSIONS: Mineral trioxide aggregate and CEM cement were associated with a similar favourable biological response to pulpotomy treatment and demonstrated a more effective induction of dentinal bridge formation compared to CH.

A scanning electron microscope study of plaque accumulation on silk and PVDF suture materials in oral mucosa.

AIM: To examine plaque accumulation on silk and polyvinylidene fluoride (PVDF) sutures at different time intervals. METHODOLOGY: Twenty-one male albino rabbits received sutures under general and local anaesthesia. After 3, 5 and 7 days sutures were removed and processed for scanning electron microscope (SEM) observation. The Friedman and the Wilcoxon tests were used to compare contamination on PVDF and silk suture materials at different time intervals. RESULTS: At all time intervals, the whole surface of silk sutures was covered with a thick layer of bacterial plaque and debris. Microorganisms and blood cells on the surface and between the filaments of the silk suture material were observed. Light debris appeared around the knot area of PVDF sutures after 3 days. At 5 and 7 days, contamination could be seen in scattered areas along the suture material. The average contaminated area was smaller on PVDF suture materials, which were removed at 5 than at 7 days after insertion. At 3 days, PVDF sutures showed significantly less contamination than at 5 and 7 days (P = 0.002). There were statistically significant differences between silk and PVDF sutures at 3, 5 and 7 days. CONCLUSION: SEM observation showed that PVDF sutures were contaminated less than silk sutures at 3, 5 and 7 days.