ENDO, 04/2011

Aim: During the past 50 years, the outcome of endodontic therapy and the factors affecting it have been the focus of over 80 clinical and laboratory studies. This review of the literature focused on the importance of the various definitive restoration considerations of endodontically treated teeth. Methods: Online search engines were used to access published journals. The clinical relevance and level of evidence they provided was considered. Results: The different restorative options, including the materials used at each stage of restoration, were identified and the advantages and disadvantages of each considered. Recommendations for their use have been made. Conclusion: Inclusion of the definitive restoration at the initial endodontic treatment planning stage is imperative to provide an optimal prognosis for a tooth following endodontic treatment. Keywords: endodontic, post, restoration, success

Mineral trioxide aggregate (MTA) has been widely used in recent times for a number of applications in the field of dentistry. MTA was first described in dental scientific literature in 1993. The aim of this literature review is to update previously published information and present a comprehensive list of articles from November 1993 to December 2010 regarding the chemical and physical properties and mechanism of action of MTA. Keywords: mechanism of action, mineral trioxide aggregate (MTA), physicochemical properties, Portland cement

The orthograde intracanal placement of mineral trioxide aggregate (MTA ) in the treatment of root canals with an open apex is technique sensitive, primarily because of its poor handling properties. Placement of the material within the confines of the root canal is difficult. The current case series presents the results of 12 treated open apex cases, using MTA condensed by hand against an internal matrix of absorbable collagen sponge (ACS) to create an apical plug. The results of the technique are encouraging, while the success of MTA in apexification has been reiterated. Keywords: absorbable collagen sponge, apexification, apical plug, MTA, open apex

This report presents a case of nonsurgical retreatment of an already apicected second mandibular premolar with asymptomatic apical periodontitis. Radiographic examination showed an insufficient coronal restoration, a poor root canal filling, a root-end filling and an apical radiolucency. Treatment was comprised of cleaning and shaping of the root canal, removal of the retrograde filling by ultrasonics and continuous irrigation, using calcium hydroxide as an intracanal dressing, and obturation of the root canal using mineral trioxide aggregate. At the 3.5-year follow-up, the tooth was asymptomatic and showed radiologically healthy periapical conditions. Keywords: apicectomy, endodontic retreatment, MTA, removal of root-end filling, surgical failure

Introduction: The aim of this study was to evaluate the effect of progressive root canal enlargement on root surface strain during obturation of oval root canals, with either cold lateral or warm vertical compaction techniques. Methods: Sixty-four anatomically comparable human mandibular incisors with oval root canals were classified into four equal groups according to the extent of root canal enlargement. Root canals were cleaned, shaped and enlarged with the ProTaper Universal system (Dentsply Maillefer) with finishing files number 1, 2, 3 and 4, respectively. Each group was further subdivided equally according to the obturation technique: warm vertical compaction (WVC) or cold lateral compaction (LC). All specimens were scanned before and after instrumentation using a multi-detector computerised tomography (CT) scanner to assess root canal volume change. The root surface strain was measured using an electrical strain gauge during obturation. Data for the change in root canal volume was subjected to one-way analysis of variance between groups (ANOVA), while root surface strain data was subjected to two-way ANOVA. Pearson's correlation coefficient was also calculated. Results: There was a significant effect for root canal enlargement and obturation technique, as well as the interaction between them on root surface strain. Significantly higher strain values were recorded during WVC than during LC. Conclusions: Progressive root canal enlargement resulted in higher root surface strain during obturation of oval root canals. Keywords: obturation technique, root canal enlargement, root strain

Aim: This ex vivo study evaluated the accuracy of three electronic apex locators (Root ZX® II, Propex II® and Elements Diagnostic®) in determining working length by comparing their findings with direct measurements. Materials and methods: Forty single-rooted human teeth underwent coronal access and cervical preparation. To determine actual working length, a size 10 K-file was inserted to the point where its tip was visible at the apical foramen under 8× magnification; a rubber stop was placed at the level of the incisal edge, and working length was measured with a millimetre endodontic ruler. The teeth were then mounted on a piece of floral foam soaked in 0.9% sodium chloride, and electronic measurements were made using the foramen identification criterion for apex location of the Root ZX II, Propex II and Elements Diagnostic units. Results: Analysis of variance (ANOVA; P = 0.9987) showed no statistically significant differences between the three electronic apex locators at either tolerance level. Root ZX II had a 93% accuracy rate, Propex II 90% and Elements Diagnostic 91%. No statistically significant differences were found between the locators being tested (P > 0.05), with a safety margin of ± 0.5 mm. Conclusion: The three locators had acceptable accuracy rates for clinical use. Keywords: apex locator, endodontics, working length

Aim: The purpose of this study was to compare the anaesthetic efficacy of inferior alveolar nerve block (IANB) using 1.7 ml of 4% articaine with 1:100,000 epinephrine in reversibly and irreversibly inflamed mandibular molars. Materials and methods: Thirty-six adult patients diagnosed with reversible or irreversible pulpitis of a mandibular molar received 1.7 ml of 4% articaine with 1:100,000 epinephrine, using a conventional IA NB. Following administration, teeth were tested with Endo-Ice® (1,1,1,2 tetrafluoroethane; Hygenic) at 5- and 10-minute intervals. The parameters to evaluate were onset of lip numbness, onset of pulpal anaesthesia and a painful or non-painful response during the procedure. Success was defined as none or mild pain upon cavity preparation or during access and instrumentation of the root canals. In case of failure, supplemental anaesthesia was administered. Statistical analysis was performed using Fisher's exact test, data on time to lip anaesthesia were analysed through survival analysis techniques, and response to cold and pain during the procedure by two-way tables. Results: The pain was too severe to proceed in 5.3% of the reversible pulpitis group and 66.7% of the irreversible pulpitis group. The trend for more pain in the irreversible pulpitis group was statistically significant (P 0.001). Pain during the procedure did not show any statistically significant association with response to cold at 5 minutes after IANB (P > 0.999) or time to onset of lip anaesthesia (P = 0.122). Conclusion: The IANB using 1.7 ml of 4% articaine with 1:100,000 epinephrine is much more likely to be inefficient in patients presenting with irreversible pulpitis than in patients with reversible pulpitis. In addition, the absence of pulpal response to Endo-Ice does not guarantee pain-free root canal procedures. Keywords: endodontic anaesthesia, inferior alveolar nerve block (IANB), irreversible pulpitis

Objective: To investigate, clinically, the efficacy of a steroid/antibiotic dressing on teeth diagnosed with reversible pulpitis. Study design: Retrospective clinical audit in a primary care setting over 12 years. Materials and methods: Patients diagnosed as suffering from reversible pulpitis were selected for this study. Following caries control, a thin layer of a steroid/antibiotic dressing was placed on the cavity floor and covered with a zinc oxide-eugenol cement as a temporary filling. The patients were reviewed 3 weeks later or earlier if symptoms were intolerable. If after 3 weeks the tooth was symptom-free, the steroid/antibiotic dressing was partially removed (leaving approximately 2 mm on the cavity floor) and the tooth was restored definitively. If the tooth was not symptom-free at review, a decision was made, depending on severity, to either re-dress the tooth with the corticosteroid/ antibiotic compound or commence root canal treatment; teeth in the latter group were then excluded from the study. All subsequent reviews and interventions required for the teeth remaining in the study were recorded accordingly. Results: The average age of the patients in this study was 54 years and 55% were females. A total of 454 teeth were treated, of which 435 (96%) needed two and 19 (4%) needed three treatment visits. Subsequent interventions included root canal treatment for 43 (10%) teeth, extraction for 21 (5%) teeth and 14 (3%) teeth were re-dressed more than once. The median survival time of the teeth was 6 years. Conclusions: This study showed that root canal treatment may not necessarily be the first line of treatment for teeth diagnosed with reversible pulpitis, even with borderline cases. Most of the teeth treated with the steroid/antibiotic dressing settled and very few were lost over a 12-year period. Keywords: cohort, Ledermix, longitudinal study, primary care, pulpitis