ENDO, 03/2015

Aim: To evaluate the preferred method of root canal length determination and the apical limit for canal instrumentation and obturation amongst endodontic teachers at a dental school. Materials and methods: A questionnaire on the preferred method of root canal length determination and the apical limit for canal instrumentation and obturation was designed and distributed to staff teaching Endodontics. Results: The response rate was 82.1%. Most of the respondents were ≤ 40 years old (52.2%), trained/qualified from a UK-based institution (78.2%); over 78.2% had a further qualification. For the majority, General Dentistry or Prosthodontics were their primary practice field (30.4% each). The full-timers were mostly in academia (50.0%); most part-timers worked in hospital services (27.3%). All used radiographs to determine working length. Additional methods included preoperative radiographs (65.2%), electronic apex locators (EALs) (87%), tactile feel (17.4%) and the paper point test technique (4.3%). The median number of length determination methods was three. The most favoured apical limit was up to 0.5 mm short of the radiographic apex for canal instrumentation (39.1%) and 1.0 mm for obturation (47.8%); the majority preferred to instrument and obturate to the same apical limit. There was a statistically significant relationship between the desired apical limit for canal instrumentation and obturation (P = 0.019). Conclusions: The most popular method for determining working length was EALs; over half used both EALs and radiography. There was no agreement on the apical limit for canal instrumentation and obturation; the most desired limit was 0.5 mm from the radiographic apex for canal instrumentation, and 1 mm for obturation. The majority preferred to both instrument and obturate to the same apical limit. Keywords: apical limit, root canal, working length

Objective: The purpose was to first identify if there was a difference between the root canal morphology of maxillary first molars of Malaysians and Caucasians by using horizontal sectioning. Secondly, it was to see if there was a difference between the root canal morphology of maxillary first molars of Malaysians and other Eastern Asian populations found in the literature. Methods: Extracted maxillary first molars were collected from a Caucasian population (n = 133) and a Malaysian population (n = 139). The mesiobuccal root was horizontally sectioned. Data was taken from the apex, 1 mm coronal to the apex, the apical one third of the root, the apical middle twothirds of the root, and the apical five-sixths of the root. Canal configuration was classified according to Vertucci's classification. Results: The greatest difference between the two populations was that of Type 1 (Caucasians: 42.86%, Malaysians: 34.56%) and Type 3 (Caucasians: 3.76%, Malaysians: 7.35%). No statistical difference was found when comparing each Vertucci type between Caucasians and Malaysians (P = 0.799). The total percentage of two mesiobuccal canals was 57.14% for Caucasians and 65.44% for Malaysians. No statistical difference was found (P = 0.171). No statistical difference was found between the total percentage of two mesiobuccal canals between Malaysians and findings in previous literature (P > 0.05). Conclusion: There was no statistically significant difference between the incidence of the second mesiobuccal canal of maxillary first molars of Caucasian, Malaysian and other Eastern Asian populations. Keywords: canal configuration, cross section, Malaysian, maxillary first molar, mesiobuccal canal, root canal anatomy

Aim: The purpose of this study was to evaluate root and canal morphology of mandibular permanent first molars in a North American population. Methods: A total of 248 cases with bilateral mandibular first molars were evaluated after meeting inclusion and exclusion criteria. All scans from cone beam computed tomography (CBCT) were carefully reviewed by two endodontists. The number of roots, occurrence of a distolingual root, and Vertucci's classification of canal types for each molar were recorded. Differences by gender and ethnicity were calculated using chi-square test and Fisher's exact test. The intra-rater reliability was assessed using Cohen's kappa statistic. Results: The symmetry rate of molars was 85.5%. There was a statistically significant difference in the occurrence of three-rooted mandibular first molars in Asians compared with other ethnic groups (P 0.0001). The most common type of root and canal morphology for mandibular first molars was two separate canals in the mesial root and one canal in the distal root. There was a statistically significant difference in Vertucci's classification of canal types amongst five ethnic groups (African- American, Asian, Caucasian non-Hispanic, Hispanic and others; P 0.0001). Conclusions: If necessary, a CBCT scan, as an adjunct to periapical radiographs, could assist in the identification of root and canal morphology of mandibular permanent first molars to facilitate root canal treatment. Keywords: cone beam computed tomography, mandibular first molar, root canal morphology, tooth anatomy

Aim: To determine the efficacy of sonic or Er,Cr:YSGG laser activation of irrigation protocols on Enterococcus faecalis biofilms in vitro. Materials and methods: E. faecalis biofilms were generated in instrumented root canals (n = 120), and randomly divided into six groups (n = 20) based on the irrigation/activation protocol. Three percent sodium hypochlorite (NaOCl) was used during instrumentation. The six groups included G1: 3% NaOCl /sonic activation; G2: 3% NaOCl/Er,Cr:YSGG laser activation; G3: 17% EDTA- 3% NaOCl/ sonic activation; G4: 17% EDTA- 3% NaOCl/Er,Cr:YSGG laser activation; G5: 3% NaOCl; and G6: saline. Bacterial viability was assessed by confocal microscopy. Dentin powder was obtained for analysing the colony forming units (CFU/ml). Data were analysed by appropriate statistical analyses with P = 0.05. Results: The biofilm along the root canal wall was completely destroyed by all groups except saline. G4 (EDTA-NaOCl / Er,Cr:YSGG activation) showed maximum bacterial destruction within the dentinal tubules of 200 μm depth (P 0.05). At 400 μm within the dentinal tubules, there was no significant difference between the groups (P > 0.05). Culture analysis showed no growth in any of the groups at 200 μm except the saline control. Conclusions: Activation of irrigants using Er,Cr:YSGG laser brought about a significant reduction of bacteria within the dentinal tubules at 200 μm depth. Keywords: biofilm, confocal microscopy, Enterococcus faecalis, laser, sodium hypochlorite, sonic

Introduction: The diagnosis and treatment of invasive cervical resorption is always challenging. Usually such cases are asymptomatic and standard radiographs do not always provide all the information, meaning they can be confused with an internal resorption. Methods: The purpose of this report was to describe two cases of invasive cervical resorption that were treated with calcium silicate cement as an alternative to mineral trioxide aggregate (MTA). In the first case surgical debridement was performed maintaining pulp vitality, and calcium silicate cement was applied as part of the restoration with 3-year follow up. In the second case, cone beam computed tomography (CBCT) was used to detect the invasive cervical resorption followed by root canal treatment, curettage of the resorbed walls, restoration and an 18-month follow-up. Conclusion: The absence of symptoms, normal radiographic aspect and the normal appearance of the surrounding tissues demonstrated that the bioactive material is suitable for repairing extensive losses of root dentin structure. Keywords: calcium silicate cement, external root resorption, invasive cervical resorption

Purpose: This study evaluated the pulp response to crude propolis, which was used as a pulpotomy agent in primary and immature permanent human teeth. Materials and methods: 24 teeth planned for orthodontic extraction were pulpotomised. This included 10 primary molars (caries-affected) and 14 immature premolars (caries-free). A glass ionomer cement was applied to a layer of propolis and the cavity was filled with a light cured composite resin. Thirteen teeth were extracted after the first month of treatment, which included five primary molars (group 1) and eight premolars (group 2), while the rest consisting of five primary molars (group 3) and six premolars (group 4) were extracted after 3 months. The histological sections were prepared and viewed under a light microscope, looking at histological signs of inflammation and the formation of a dentine bridge. Results: After 1 month of treatment in group 1, three cases showed no inflammation, while one tooth showed a moderate and one a severe inflammation. In group 2, five cases showed no inflammation, while a moderate inflammation was recorded in two, and severe in one tooth. After 3 months in group 3, all cases showed no inflammation. In group 4, three cases showed no and three showed a severe inflammation. A dentine bridge was formed in all groups: three, six, four and four cases for groups 1, 2, 3 and 4, respectively. Conclusion: Syrian crude propolis seemed to reduce pulp inflammation response and induced formation of a dentine bridge, when used as a pulpotomy agent in primary and immature permanent teeth. Keywords: dentine bridge, inflammation, propolis, pulpotomy

This report demonstrates that root canal treatment of dens invaginatus in a maxillary lateral incisor with a sinus tract and large periradicular lesion can be successfully managed over a long period of time. The aim of this article is to show that contemporary technology, including a dental microscope and modern materials like mineral trioxide aggregate, are essential to secure a high survival of teeth, which have a difficult anatomy. The complex morphology of the root canal system and the invagination requires accurate intracoronal inspection, in order to find all delicate parts that need to be instrumented, disinfected and obturated. An 11-year-old girl with a type III dens invaginatus was referred to the Department of Operative Dentistry. A multiple-visit endodontic procedure was necessary to find, instrument and seal both the root canal and the invagination successfully. The presented case was treated by means of conventional non-surgical root canal treatment and apical placement of ProRoot MTA (Dentsply DeTrey, Konstanz, Germany). At 10-year follow-up the tooth was asymptomatic (no response to percussion or palpation) and complete periapical bone healing was observed radiographically. In the meantime the tooth was restored with a ceramic crown. Keywords: dens in dente, dens invaginatus, dental malformation, root canal treatment

Fusion is a developmental disturbance of dental hard tissues resulting from the union of two adjacent tooth germs. This report discusses the multi-disciplinary management of a maxillary central incisor fused with a supernumerary tooth with apical periodontitis and a fractured crown. Non-surgical root canal treatment using a mineral trioxide aggregate (MTA) plug as an apical seal was performed on the fused teeth followed by aesthetic restoration with glass fibre posts and composite resin. The patient remained asymptomatic and the periapical pathosis completely healed 1 year later. The aim of this article is to describe the diagnostic process and the significance of it is the final outcome and the clinical problems faced during the management of this case. Its early and accurate diagnosis is pivotal for successful root canal treatment. Keywords: aesthetics, developmental anomaly, fusion, MTA plug, supernumerary teeth