The aims of this paper were to review the studies that investigated the root and root canal morphology of permanent dentition in the Saudi Arabian population and to compare their results with the findings of international morphological studies conducted on other populations. An electronic search using the PubMed and Scopus databases was conducted using combination of the following keywords: "root canal morphology", "root morphology", "dental anomalies", and "Saudi Arabian population". In addition, all issues of the Saudi Dental Journal (since 1989) and Saudi Endodontic Journal (since 2011) were manually searched for relevant articles. Then, the reference lists of the articles were screened to identify further eligible publications. A total of 23 studies met the inclusion criteria and were subjected to data extraction and analysis. Variations from the normal root and canal morphology may occur in all populations including the Saudi Arabian population. Therefore, the clinicians must always take these variations in consideration during root canal treatment to ensure a successful treatment outcome.

Avulsion of tooth is complete displacement of tooth out of its socket that results in mutilation of periodontal ligaments. The desirable treatment option is replantation of the tooth. However, unsuccessful replantation is a matter of great discontentment. Unsuccessful replantation is due to inappropriate management of the avulsed tooth. Protection of teeth from desiccation due to drying of the periodontal ligament tissue, by keeping it in storage media can improve the outcome of the treatment. This review paper focuses on the use of natural products as storage media for avulsed teeth. In vitro and in vivo research published during 1995-2014, allowing open access on National Center for Biotechnology Information (NCBI) database and articles on EBSCO host (EBSCO-Elton B. Stephens Company) were included. It was found that natural products such as milk, coconut water, propolis, green tea, red mulberry, Aloe vera, egg-white and pomegranate have shown ability to maintain viability of periodontal ligament cells of avulsed teeth. Few natural products such as coconut water and milk can be used in raw form, while other products such as green tea and red mulberry need processing. Ability to maintain periodontal cell viability for a longer time is warranted in cases of major accidents, where teeth can be replanted only after other major surgeries. Natural products have easy availability, greater efficacy and longer storage time as compared to Hank's balanced salt solution which has been recommended by the International Association of Dental Traumatology as standard solution for storage of avulsed teeth. Natural products have shown good qualities in in vitro experiments; further in vivo studies are needed to evaluate their efficacy as storage media.

Introduction: Cleanliness of the canal space is the ultimate goal of its preparation. Nevertheless, some portion of the canal walls are left un-instrumented during preparation. Therefore, the aim of this ex vivo study was to evaluate the cleanliness of un-instrumented canal walls after root canal preparation for the presence or absence of debris and smear layer. Materials and Methods: A total of 24 single-rooted extracted teeth were prepared with the crown-down technique using Protaper universal rotary file system. Micro-computed tomography (micro-CT) was used to scan the specimens before and after instrumentation. The un-instrumented area was measured and localized. The roots were split longitudinally and then subjected to scanning electron microscopy (SEM). The presence of debris and smear layer in the instrumented and un-instrumented areas of the canal were evaluated by analysing the SEM images with a five-score evaluation system based on the reference photographs. Results: High levels of root canal cleanliness (≤ score 2) were found for the instrumented areas were detected (P = 0.003). Conclusions: Under the condition of this study, un-instrumented areas of the canal were less clean in comparison to instrumented portion.

Aim: The aim of this histological study was to evaluate the different causes of the failures of the endodontic treatment. Materials and Methods: Adult patients who were referred for endodontic surgery and for whom root-end resection was considered suitable were invited to participate in this study. The inclusion criteria were: (1) Patients aged between 18 and 65 years; (2) teeth with apical periodontitis that was diagnosed radiographically; (3) the tooth could not be adequately and better managed by root-canal retreatment; and (4) the crown of the tooth was adequately restored. One hundred root apices were surgically removed together with the periapical pathological tissue from 92 patients (56 males and 36 women).Histological sectioning was performed on calcified specimens that were embedded in a suitable medium. Results: The causes of endodontic failure identified through histological evaluation were as follows: Presence of bacterial and debris into canals (51%), apex transposition and overfilling (3%), presence of the isthmus (21%), bacterial colonization of root surface (2%), untreated canals (11%), and filling material outside root canal (4%). There was no significant difference between the distribution of teeth and the causes of endodontic failures (P = 0.32). Conclusions: The present study demonstrated that the most common cause of endodontic failure is the insufficient cleaning of the root canal system. It also explores the effectiveness of histological evaluation of the root apex following root-end resection in exploring the causes of endodontic failures.

Objectives: The aim of the study was to compare manual dynamic agitation with sonic agitation on removal of intra radicular Enterococcus faecalis (E. faecalis) biofilm. Material and Methods: Extracted mandibular premolars for orthodontic purpose were sectioned at cervical level and divided into three groups (n = 30). The root canals were instrumented using Protaper rotary instruments up to apical file F4. Roots were sterilized and E. faecalis bacteria were incubated within their root canal space for four weeks. Confirmation of biofilm was done using scanning electron microscopy and Gram staining. All groups were irrigated with side vented needle by using three percent sodium hypochlorite (NaOCl) for 60 seconds. Two experimental groups were agitated with manual dynamic agitation (with master gutta-percha cone) and sonic agitation (EndoActivator). Remaining bacteria were collected using sterile paper point, which were incubated inside brain-heart infusion (BHI) broth to check turbidity. The turbid broth was streaked on blood agar plate for colony counts. Result: Both experimental groups showed highly significant difference in their mean colony count when compared with control group; with P < 0.001. Conclusion: Passive sonic agitation with EndoActivator has proven to be the best irrigating system followed by manual dynamic agitation and conventional needle irrigation.

Aims: The aim of this study was to evaluate the variation of vertical angle for detection of fractures. Materials and Methods: Twenty-five (25) single-rooted premolar teeth were divided into two groups, fractured teeth (n = 15) and non-fractured teeth (n = 10). Artificially fractured teeth were classified according to location, number of fragments, and direction of fracture line: Horizontal, oblique, or complex. The tooth fragments were juxtaposed with cyanoacrylate, and the specimens (fractured and non-fractured) were placed individually in the dental alveolus of a human jaw with the aid of silicone rubber impression material and submitted to eight periapical radiographs in a digital sensor with a vertical range of 10 degrees (−40, −30, −20, −10, 0, +10, +20, +30). Three examiners evaluated the characteristics of the fractures and their correlation with the radiographic diagnosis (perceived or not) by varying the vertical angle. Statistical Analysis: Descriptive analysis was performed through the analytical comparison and Kappa test inter-examiner. Results: Among the three examiners, inter-examiner Kappa value was 0.536. The radiographic identification of root fracture in the 15 prepared samples was 60% (nine) at angle 0, and at the angles of +10, −10, and −20, it was less than 50%. Conclusions: Multiple radiographs with variations of vertical angle are fundamental to facilitate the diagnosis of horizontal root fractures in premolars.

Objectives: The purpose of this study was to determine how the Dental Operating Microscope (DOM) is currently being accepted for usage by endodontists in the Middle East. Materials and Methods: A one-page letter and auto-return upon completion computer-based questionnaires were e-mailed to most of the active members of the Middle Eastern endodontic associations. Results: Out of the 47% that are using the DOM, only 35% answered yes to using the DOM as much as anticipated. The reasons for not using the DOM as much as anticipated were positional difficulties (80%) and increased treatment time (75%). The majority of endodontists reported that they always use it during retrieval of separated instruments, negotiating calcified canals and surgical treatment. Conclusions: The findings revealed that endodontists in the younger age-groups are more accepting of the DOM. It was also found that the endodontists that are using the DOM in their practice are not using it as often as they anticipated.

Mental nerve paraesthesia can occur as a result of a variety of reasons. Paraesthesia following endodontic treatment is an uncommon treatment complication. Causes of paraesthesia in the mental nerve region are reviewed and two cases involving endodontic treatment are discussed. In the first instance, a patient presented with difficulty in swallowing and severe pain localized to her right mandible, with numbness of her lower lip. Paraesthesia resolved quickly with endodontic treatment. In the second instance, a patient referred for treatment a mandibular second premolar developed profound paraesthesia in the distribution of the mental nerve after treatment. The local anesthetic used was 4% articaine by infiltration. CBCT imaging revealed two accessory mental foramen and slight extrusion of sealant into one of the neurovascular exits. Possible causes of paraesthesia are discussed in the light of the literature review. CBCT imaging may be useful in the diagnosis and management of these conditions.

Inability to find and manage an extra canal (s) is an important cause forfailure of root canal treatment. So, for effective and successful endodontic therapy, root canal morphology and variations should be considered. The purpose of this case report is to present a case of a 58-year-old Saudi male patient with anatomical variations in permanent maxillary left canine in which there is an additional canal (type II of Vertucci classification) was located and treated.