Yl Ng

A prospective study of the factors affecting outcomes of nonsurgical root canal treatment: part 1: periapical health.

AIMnTo investigate the probability of and factors influencing periapical status of teeth following primary (1°RCTx) or secondary (2°RCTx) root canal treatment.nnnMETHODOLOGYnThis prospective study involved annual clinical and radiographic follow-up of 1°RCTx (1170 roots, 702 teeth and 534 patients) or 2°RCTx (1314 roots, 750 teeth and 559 patients) carried out by Endodontic postgraduate students for 2-4 (50%) years. Pre-, intra- and postoperative data were collected prospectively on customized forms. The proportion of roots with complete periapical healing was estimated, and prognostic factors were investigated using multiple logistic regression models. Clustering effects within patients were adjusted in all models using robust standard error.nnnRESULTSnproportion of roots with complete periapical healing after 1°RCTx (83%; 95% CI: 81%, 85%) or 2°RCTx (80%; 95% CI: 78%, 82%) were similar. Eleven prognostic factors were identified. The conditions that were found to improve periapical healing significantly were: the preoperative absence of a periapical lesion (P = 0.003); in presence of a periapical lesion, the smaller its size (P ≤ 0.001), the better the treatment prognosis; the absence of a preoperative sinus tract (P = 0.001); achievement of patency at the canal terminus (P = 0.001); extension of canal cleaning as close as possible to its apical terminus (P = 0.001); the use of ethylene-diamine-tetra-acetic acid (EDTA) solution as a penultimate wash followed by final rinse with NaOCl solution in 2°RCTx cases (P = 0.002); abstaining from using 2% chlorexidine as an adjunct irrigant to NaOCl solution (P = 0.01); absence of tooth/root perforation (P = 0.06); absence of interappointment flare-up (pain or swelling) (P =0.002); absence of root-filling extrusion (P ≤ 0.001); and presence of a satisfactory coronal restoration (P ≤ 0.001).nnnCONCLUSIONSnSuccess based on periapical health associated with roots following 1°RCTx (83%) or 2°RCTx (80%) was similar, with 10 factors having a common effect on both, whilst the 11th factor EDTA as an additional irrigant had different effects on the two treatments.

Contemporary Root Canal Irrigants Are Able to Disrupt and Eradicate Single- and Dual-Species Biofilms

INTRODUCTIONnClinical/microbiological studies have consistently revealed the persistence of some bacteria after conventional root canal debridement. Although this was originally attributed to the complexity of the root canal anatomy and the difficulty of delivering antibacterial agents effectively, it has emerged that the biofilm encasement of bacterial cells may confer a further mechanism of resistance. The purpose of this study was to investigate the relative disruption and bactericidal effects of root canal irrigants on single- and dual-species biofilms of root canal isolates.nnnMETHODSnBiofilms of Streptococcus sanguinis, Enterococcus faecalis, Fusobacterium nucleatum, and Porphyromonas gingivalis were grown on nitrocellulose membranes for 72 hours and immersed in NaOCl, EDTA, chlorhexidine, and iodine for 1, 5, or 10 minutes. The number of viable and nonviable bacteria disrupted from the biofilm and those remaining adherent were determined by using a viability stain in conjunction with fluorescence microscopy.nnnRESULTSnGram-negative obligate anaerobe species were more susceptible to cell removal than gram-positive facultative anaerobes. The majority of cells were disrupted after the first minute of exposure; however, the extent varied according to the agent and species. The most effective agent at disrupting biofilms was NaOCl. Iodine was generally effective at bacterial killing but not disruption.nnnCONCLUSIONSnBiofilm disruption and cell viability were influenced by the species, their coassociation in dual-species biofilms, the test agent, and the duration of exposure. The effectiveness of NaOCl as an endodontic irrigant was reinforced.

Evaluation of Protocols for Field Decontamination Before Bacterial Sampling of Root Canals for Contemporary Microbiology Techniques

The effectiveness of sodium hypochlorite (NaOCl) (2.5%) or iodine (10%) for decontamination of the operation field (tooth, rubber dam, and gasket [Oraseal]) was compared by using bacterial cultivation. In addition, the final samples were also assessed for bacteria by using polymerase chain reaction. Teeth (n = 63) receiving root canal treatment were polished with pumice, isolated with rubber dam, and their margins sealed with Oraseal. The operation field was disinfected with hydrogen peroxide (30%), followed by iodine (n = 31) or NaOCl (n = 32), before and after access cavity preparation. The operation field was sampled before and after each decontamination, giving four samples per field. After the final decontamination, there was no significant difference (p = 0.602, 0.113, 0.204) in recovery of cultivable bacteria from various sites in either group. However, bacterial DNA could be detected significantly (p = 0.010) more frequently from the tooth surfaces after iodine (45%) compared with NaOCl (13%) decontamination, although on the rubber dam or Oraseal surfaces there was no difference. Root canal sampling for polymerase chain reaction might be better preceded by NaOCl decontamination than by iodine, based on the findings.

Ion release characteristics, precipitate formation and sealing ability of a phosphate glass-polycaprolactone-based composite for use as a root canal obturation material

OBJECTIVESnThe filling material used to obturate root canal systems during the common dental procedure, root canal treatment, has popularly involved gutta-percha (GP) in one of its many forms for almost a 100 years. An optimal root filling material should provide a predictable seal, inhibit or kill residual bacteria, prevent re-contamination and facilitate periapical healing. Although the goal of obturation is stated as the creation of a seal, its precise role still remains elusive and the seal offered suspect. The primary goal of the study was to develop a novel polycaprolactone/phosphate glass composite deliverable as a root filling and capable of releasing ionic species to enable a predictable seal in an aqueous environment.nnnMATERIALS AND METHODSnDifferent compositions of polycaprolactone-iron phosphate glass (Fe(2)O(3) 1, 3 and 5mol%) composites were produced and delivered into an ex vivo root canal model. Standardized root canals were prepared in extracted human teeth. The teeth were examined for root filling adaptation and precipitate formation (SEM), ion release (Na(+), Ca(2+), PO(4)(3-), P(2)O(7)(4-), P(3)O(9)(3-), and P(5)O(10)(5-)), and sealing ability. The experiments were controlled with teeth obturated with contemporary GP and a conventional zinc-oxide/eugenol sealer.nnnRESULTSnAdaptation of the experimental material was statistically significantly better than the GP control groups. Precipitate formation was noted in some specimens but all released various ionic species in an inverse proportion to the iron oxide concentration. The experimental material exhibited significantly (P<0.001) less leakage after 7 days immersion in saline compared with those not immersed, or the control GP group.nnnSIGNIFICANCEnPCL-phosphate glass composites showed good potential as a root filling material capable of producing a seal in an aqueous environment without a sealer.

Investigation to test potential stereolithography materials for development of an in vitro root canal model

The aims were to compare the physico‐chemical properties (zeta‐potential, wettability, surface free energy) of stereolithography materials (STL) (Photopolymer, Accura) to dentine and to evaluate the potential of each material to develop Enterococcus faecalis biofilm on their respective surfaces. Eighteen samples of each test material (Photopolymer, Accura, dentine) were employed (total nu2009=u200954) and sectioned to 1 mm squares (5u2009mm x 5u2009mm) (nu2009=u200915) or ground into a powder to measure zeta‐potential (nu2009=u20093). The zeta‐potential of the powder was measured using the Nano‐Zetasizer technique. The contact angle (wettability, surface free energy tests) were measured on nine samples using goniometer. The biofilm attachment onto the substrate was assessed on the samples of each material using microscope and image processing software. The data were compared using one‐way ANOVA with Dunnett post‐hoc tests at a level of significance Pu2009≤u20090.05. Both STL materials showed similar physico‐chemical properties to dentine. The materials and dentine had negative charge (Accura: −23.7u2009mv, Photopolymer: −18.8u2009mv, dentine: −9.11u2009mv). The wettability test showed that all test materials were hydrophilic with a contact angle of 47.5°, 39.8°, 36.1° for Accura, Photopolymer and dentine respectively, and a surface free energy of 46.6, 57.7, 59.6 mN/m for Accura, Photopolymer and dentine, respectively. The materials and dentine proved suitable for attachment and growth of E. faecalis biofilm with no statistical differences (Pu2009>u20090.05). Stereolithography materials show similar physico‐chemical properties and growth of E. faecalis biofilm to dentine. Therefore, they may be an alternative to tests requiring dentine.

Injectable local anaesthetic agents for dental anaesthesia

BACKGROUNDnPain during dental treatment, which is a common fear of patients, can be controlled successfully by local anaesthetic. Several different local anaesthetic formulations and techniques are available to dentists.nnnOBJECTIVESnOur primary objectives were to compare the success of anaesthesia, the speed of onset and duration of anaesthesia, and systemic and local adverse effects amongst different local anaesthetic formulations for dental anaesthesia. We define success of anaesthesia as absence of pain during a dental procedure, or a negative response to electric pulp testing or other simulated scenario tests. We define dental anaesthesia as anaesthesia given at the time of any dental intervention.Our secondary objective was to report on patients experience of the procedures carried out.nnnSEARCH METHODSnWe searched the Cochrane Central Register of Controlled Trials (CENTRAL; the Cochrane Library; 2018, Issue 1), MEDLINE (OVID SP), Embase, CINAHL PLUS, WEB OF SCIENCE, and other resources up to 31 January 2018. Other resources included trial registries, handsearched journals, conference proceedings, bibliographies/reference lists, and unpublished research.nnnSELECTION CRITERIAnWe included randomized controlled trials (RCTs) testing different formulations of local anaesthetic used for clinical procedures or simulated scenarios. Studies could apply a parallel or cross-over design.nnnDATA COLLECTION AND ANALYSISnWe used standard Cochrane methodological approaches for data collection and analysis.nnnMAIN RESULTSnWe included 123 studies (19,223 participants) in the review. We pooled data from 68 studies (6615 participants) for meta-analysis, yielding 23 comparisons of local anaesthetic and 57 outcomes with 14 different formulations. Only 10 outcomes from eight comparisons involved clinical testing.We assessed the included studies as having low risk of bias in most domains. Seventy-three studies had at least one domain with unclear risk of bias. Fifteen studies had at least one domain with high risk of bias due to inadequate sequence generation, allocation concealment, masking of local anaesthetic cartridges for administrators or outcome assessors, or participant dropout or exclusion.We reported results for the eight most important comparisons.Success of anaesthesiaWhen the success of anaesthesia in posterior teeth with irreversible pulpitis requiring root canal treatment is tested, 4% articaine, 1:100,000 epinephrine, may be superior to 2% lidocaine, 1:100,000 epinephrine (31% with 2% lidocaine vs 49% with 4% articaine; risk ratio (RR) 1.60, 95% confidence interval (CI) 1.10 to 2.32; 4 parallel studies; 203 participants; low-quality evidence).When the success of anaesthesia for teeth/dental tissues requiring surgical procedures and surgical procedures/periodontal treatment, respectively, was tested, 3% prilocaine, 0.03 IU felypressin (66% with 3% prilocaine vs 76% with 2% lidocaine; RR 0.86, 95% CI 0.79 to 0.95; 2 parallel studies; 907 participants; moderate-quality evidence), and 4% prilocaine plain (71% with 4% prilocaine vs 83% with 2% lidocaine; RR 0.86, 95% CI 0.75 to 0.99; 2 parallel studies; 228 participants; low-quality evidence) were inferior to 2% lidocaine, 1:100,000 epinephrine.Comparative effects of 4% articaine, 1:100,000 epinephrine and 4% articaine, 1:200,000 epinephrine on success of anaesthesia for teeth/dental tissues requiring surgical procedures are uncertain (RR 0.85, 95% CI 0.71 to 1.02; 3 parallel studies; 930 participants; very low-quality evidence).Comparative effects of 0.5% bupivacaine, 1:200,000 epinephrine and both 4% articaine, 1:200,000 epinephrine (odds ratio (OR) 0.87, 95% CI 0.27 to 2.83; 2 cross-over studies; 37 participants; low-quality evidence) and 2% lidocaine, 1:100,000 epinephrine (OR 0.58, 95% CI 0.07 to 5.12; 2 cross-over studies; 31 participants; low-quality evidence) on success of anaesthesia for teeth requiring extraction are uncertain.Comparative effects of 2% mepivacaine, 1:100,000 epinephrine and both 4% articaine, 1:100,000 epinephrine (OR 3.82, 95% CI 0.61 to 23.82; 1 parallel and 1 cross-over study; 110 participants; low-quality evidence) and 2% lidocaine, 1:100,000 epinephrine (RR 1.16, 95% CI 0.25 to 5.45; 2 parallel studies; 68 participants; low-quality evidence) on success of anaesthesia for teeth requiring extraction and teeth with irreversible pulpitis requiring endodontic access and instrumentation, respectively, are uncertain.For remaining outcomes, assessing success of dental local anaesthesia via meta-analyses was not possible.Onset and duration of anaesthesiaFor comparisons assessing onset and duration, no clinical studies met our outcome definitions.Adverse effects (continuous pain measured on 170-mm Heft-Parker visual analogue scale (VAS))Differences in post-injection pain between 4% articaine, 1:100,000 epinephrine and 2% lidocaine, 1:100,000 epinephrine are small, as measured on a VAS (mean difference (MD) 4.74 mm, 95% CI -1.98 to 11.46 mm; 3 cross-over studies; 314 interventions; moderate-quality evidence). Lidocaine probably resulted in slightly less post-injection pain than articaine (MD 6.41 mm, 95% CI 1.01 to 11.80 mm; 3 cross-over studies; 309 interventions; moderate-quality evidence) on the same VAS.For remaining comparisons assessing local and systemic adverse effects, meta-analyses were not possible. Other adverse effects were rare and minor.Patients experiencePatients experience of procedures was not assessed owing to lack of data.nnnAUTHORS CONCLUSIONSnFor success (absence of pain), low-quality evidence suggests that 4% articaine, 1:100,000 epinephrine was superior to 2% lidocaine, 1:100,000 epinephrine for root treating of posterior teeth with irreversible pulpitis, and 2% lidocaine, 1:100,000 epinephrine was superior to 4% prilocaine plain when surgical procedures/periodontal treatment was provided. Moderate-quality evidence shows that 2% lidocaine, 1:100,000 epinephrine was superior to 3% prilocaine, 0.03 IU felypressin when surgical procedures were performed.Adverse events were rare. Moderate-quality evidence shows no difference in pain on injection when 4% articaine, 1:100,000 epinephrine and 2% lidocaine, 1:100,000 epinephrine were compared, although lidocaine resulted in slightly less pain following injection.Many outcomes tested our primary objectives in simulated scenarios, although clinical alternatives may not be possible.Further studies are needed to increase the strength of the evidence. These studies should be clearly reported, have low risk of bias with adequate sample size, and provide data in a format that will allow meta-analysis. Once assessed, results of the 34 Studies awaiting classification (full text unavailable) may alter the conclusions of the review.

Biofilm-Associated Infections in Root Canals: Treatment and Outcomes

Root canal infections are essentially characterised by microbial biofilms that adhere to the root canal dentine and extend to the apical foramina and in some cases beyond. Primary objectives of root canal treatment are to eliminate these biofilms by using chemomechanical treatment protocols and to prevent reinfection. Desired outcomes of effective treatment are the discontinuation of destructive aspects of the host immune response and apical healing. This chapter reviews different treatment factors and their influence on the outcome of biofilm-associated infections in root canals.