ENDO, 03/2019

The use of gutta-percha in dentistry and in particular root canal procedures has a long and tortuous history; its use has been the preferred obturation material of choice for well over a century, in spite of attempts to eliminate it for other entities that were erroneously perceived to be superior. However, because of the importance of asepsis and bacteriological control in the delivery of quality root canal procedures, the clinical disinfection of gutta-percha cones has arisen as a controversial issue as to its need and the use of the most effective agent for rapid chairside management. This review will touch upon a brief history of the material and subsequently delve into the issues surrounding the decontamination/disinfection of this material in the hope to establish the best evidence for the clinical choice of managing this challenge. Keywords: antibiotics, atomic force microscopy, chlorhexidine, culturing, decontamination, disinfection, glutaraldehyde, gutta-percha, NaOCl

Objective: To compare the success of an inferior alveolar nerve block (IANB) after injecting a combination of mepivacaine + tramadol, mepivacaine alone, or lignocaine in patients with symptomatic irreversible pulpitis (SIP) in mandibular permanent molars. Materials and methods: Three study groups, each consisting of 30 patients exhibiting SIP on the first or second mandibular molars were assessed for preoperative pain according to a modified Heft-Parker visual analogue scale (VAS). Patients were anaesthetised using the IANB technique by administering identical cartridges containing either: 1.3 ml of 3% mepivacaine plain + 0.5 ml of 50 mg/ml tramadol; 1.8 ml of 3% mepivacaine; or 1.8 ml of 2% lignocaine with 1:100,000 adrenaline. After 15 minutes, lip numbness was confirmed and the efficacy of anaesthesia was evaluated by a progressive four-test examination; namely, pulp sensibility cold test, presence of pain when manipulating dental hard tissues (access opening), and accessing the pulp within chamber and root canals. The success of IANB was defined as the absence of pain during any of these evaluations. The Kruskal-Wallis test to compare mean pain scores among the groups, and the Wilcoxon signed-ranks test for pairwise VAS (pre- and post-anaesthesia) comparison were applied. Results: The success rates of anaesthesia were 70%, 53% and 57% for mepivacaine-tramadol, mepivacaine alone and lignocaine groups, respectively, which was not statistically significant (P > 0.05). Conclusion: The three anaesthetics tested achieved similar success for IANB in SIP patients, with no statistically significant difference. Keywords: inferior alveolar nerve block, lignocaine, mepivacaine-tramadol, symptomatic irreversible pulpitis, visual analogue pain scale

Objective: To assess the clinical and radiological success of permanent molar pulpotomy in children and adolescents with clinical signs and symptoms of irreversible pulpitis (IP) using white mineral trioxide aggregate (WMTA) as a pulp dressing material after 1 year. Materials and methods: Nineteen patients with 19 permanent molars demonstrating signs and symptoms of symptomatic/asymptomatic IP were included. After standardised pulpotomy was performed, 5% sodium hypochlorite was used to obtain haemostasis. A mixture of WMTA was placed in the pulp chamber. Molars were restored with glass ionomer, and in some of the cases restored with full crowns. Results: The success rate was 94.7%, as one case developed an acute apical abscess on day 7 after the initial treatment. The mean time for recalls was 14.2 ± 4.1 months. Time to stop pulpal haemorrhage ranged between 1 and 12 minutes (mean 4.89 ± 3.4 minutes). At the beginning of the study, seven molars had open apices (36.8%), and all of them showed continued root maturation. Four molars showed radiographic apical radiolucencies (21.1%); all lesions healed completely by the end of the follow-up period. Narrowing of the root canal was observed without complete obliteration in five molars (26.3%). There was no periradicular bone or root resorption. Additionally, no evidence of internal root resorption was noticed. Conclusion: The favourable outcomes of this prospective study suggest that WMTA may be used as a simple, valuable and valid pulpotomy agent in the treatment of permanent molars with IP. More studies are required to assess this procedure, in particular studies with a larger number of patients over a longer period of recalls. Keywords: irreversible pulpitis, mineral trioxide aggregate (MTA), molar pulpotomy

Objective: To assess the reparative hard tissue formed following direct pulp capping in carious permanent first molars using Biodentine (BD) and mineral trioxide aggregate (MTA) in 10- to 13-year-old children. Materials and methods: A total of 30 carious permanent mandibular first molars with vital pulp from 21 participants were included in the study. The teeth received BD or MTA as direct capping material over the exposed pulp tissue. By the end of the 8-week follow-up period, the outcome of the procedure was clinically assessed for signs of failure and for density, thickness and volume of the formed hard tissue using cone beam computed tomography (CBCT). Results: None of the teeth from both the BD and MTA groups showed signs of clinical failure by the end of the follow-up period. Reparative hard tissue formation was evident in all assessed CBCT images. The formed hard tissue in the BD group did not present higher statistically significant mean average thicknesses compared with the MTA group (P > 0.05); however, the density of hard tissue from the BD group was significantly higher (P 0.05) than that from the MTA group. Conclusions: Tricalcium silicate-based materials can be used with a high rate of success in direct pulp capping of teeth affected with caries in 10- to 13-year-olds. CBCT may represent an effective method for early detection of reparative hard tissue formation. Also, the hard tissue formed using BD showed higher density and thickness compared with MTA. Keywords: Biodentine, direct pulp capping, mineral trioxide aggregate (MTA)

Objective: The aim of this study was to evaluate the in-vitro antimicrobial activity of Azadirachta indica (neem) and Salvadora persica (miswak) extracts as endodontic irrigants against Enterococcus faecalis in comparison to NaOCl solution. Materials and methods: Apical canal enlargement of 50 single-rooted teeth was performed up to size 40 K-file. Each root specimen was autoclaved in a glass tube containing 3 ml of brain heart infusion broth. Neem leaves and miswak extracts were prepared using absolute ethanol. After root canal infection with E. faecalis, samples were divided into five groups according to the type of solution used: normal saline (group A), NaOCl solution (group B), neem leaves extract (group C), miswak extract (group D) and a combination of NaOCl and neem leaves extract (group E). A microbiological sample was taken from each root canal and the number of bacterial colonies for E. faecalis was counted and expressed as colony forming units (CFU). Results: The number of CFU was statistically significant between groups (P = 0.001). The lowest mean value of CFU was noticed with group E. Conclusions: Neem leaf extract can be used as endodontic irrigant with an effective antimicrobial property against E. faecalis. The combination of herbs and chemical agents can produce a synergistic antimicrobial effect.

Objective: The present study compared the cyclic fatigue and torsional resistance of size 25/0.06 taper of One Curve (OC), 2Shape (TS), ProFile Vortex (PV) and OneShape (OS) instruments. Materials and methods: The cyclic fatigue resistance of instruments was tested in simulated canals with 90-degree angle of curvature until fracture. The number of cycles to fracture (NCF) was recorded. The torsional resistance was determined by counting the number of load applications before instrument fracture. Data were statistically analysed and Weibull analysis was conducted on NCF data. Statistical significance was set at P 0.05. Results: OC had the highest NCF between the tested instruments (P 0.001). Nevertheless, OS showed the highest torsional resistance compared with other instruments (P 0.001). The predicted cycles of OC were 238 cycles for 99% survival. On the other hand, OS instruments had the lowest predicted cycles (60 cycles) compared with other instruments. Conclusion: OC instrument (C-Wire) had a higher cyclic fatigue resistance but a lower torsional resistance. TS and PV heat-treated nickel-titanium (NiTi) alloys enhanced the cyclic fatigue resistance of rotary instruments compared with OS conventional NiTi instruments. OS instruments displayed superior torsional resistance compared with other instruments. Keywords: cyclic fatigue, heat treatment, One Curve, torsional resistance

Objective: To assess the antibacterial efficacy of chitosan nanoparticles (CSNPs), calcium hydroxide (Ca(OH)2) and double antibiotic paste (DAP) against 3-week-old Enterococcus faecalis biofilm. Materials and methods: Sixty extracted mandibular premolars were standardised to a specimen length (14 mm), instrumented and, after sterilisation, inoculated with E. faecalis and incubated for 3 weeks. Biofilm formation was confirmed by scanning electron microscopy in four randomly selected specimens. The remaining specimens (n = 56) were divided into four groups (n = 14): Group 1, 20 mg/ml CSNPs in methylcellulose; Group 2, 35% Ca(OH)2 in methylcellulose; Group 3, 1 mg/ml DAP in methylcellulose; and Group 4, methylcellulose gel (control group). Each group was further divided into two equal subgroups (n = 7) and incubated for 7 or 14 days. After each test period, a sample of the biofilm was collected from each specimen, plated, and the antimicrobial efficacy assessed via colony forming units count (CFU/ml). Results: All the antibacterial agents evaluated resulted in complete eradication of E. faecalis after 14 days. However, Ca(OH)2 was the only medicament that provided a significant bacterial count reduction after 7 days (P 0.05). No statistically significant difference was found between Ca(OH)2, CSNPs, and DAP (P ≥ 0.05). Conclusions: A 14-day period of dressing with CSNPs, Ca(OH)2, or DAP resulted in effective antibacterial action on the 3-week-old E. faecalis biofilm. Keywords: calcium hydroxide, chitosan nanoparticles, double antibiotic paste, endodontic regeneration, Enterococcus faecalis

Background: Odontogenic fascial space infections originate from infected root canal(s) and can spread through the periapical area of a tooth to the surrounding bone and overlying soft tissues. Microbial causative agents of these lesions can be present in the form of an intraradicular or extraradicular infection and their treatment can be particularly problematic. Case presentation: A successful outcome of a therapy to treat a chronic apical abscess with mental space involvement and cutaneous sinus tract in a 20-year-old patient is presented in this case report. The treatment was performed by means of surgical decompression and ozone treatment. Twenty months after the end of treatment the patient was asymptomatic and the control radiographs revealed the healing of the periapical tissues. At the 4-year recall the periapical radiographs revealed the absence of the periapical lesion. Though the surgical intervention with complete enucleation of a periapical lesion may be the most expeditious treatment option, it can cause undesirable consequences. Conclusion: This article demonstrates how a conservative approach in therapy can offer a favourable outcome, allowing the practitioner to choose an alternative treatment option. Keywords: ozone, periapical abscess, periapical periodontitis, root canal therapy, surgical decompression