The restoration of root filled teeth: a review of the clinical literature.

Clinicians often face dilemmas regarding the most appropriate way to restore a tooth following root canal treatment. Whilst there is established consensus on the importance of the ferrule effect on the predictable restoration of root filled teeth, other factors, such as residual tooth volume, tooth location, number of proximal contacts, timing of the definitive restoration and the presence of cracks, have been reported to influence restoration and tooth survival. The continued evolution of dental materials and techniques, combined with a trend towards more conservative endodontic-restorative procedures, prompts re-evaluation of the scientific literature. The aim of this literature review was to provide an updated overview of the existing clinical literature relating to the restoration of root filled teeth. An electronic literature search of the PubMed, Ovid (via EMBASE) and MEDLINE (via EMBASE) databases up to July 2020 was performed to identify articles that related the survival of root filled teeth and/or restoration type. The following and other terms were searched: restoration, crown, onlay, root canal, root filled, post, clinical, survival, success. Wherever possible, only clinical studies were selected for the literature review. Full texts of the identified articles were independently screened by two reviewers according to pre-defined criteria. This review identifies the main clinical factors influencing the survival of teeth and restorations following root canal treatment in vivo and discusses the data related to specific restoration type on clinical survival.

External cervical resorption: part 2 - management.

Effective management of external cervical resorption (ECR) depends on accurate assessment of the true nature and accessibility of ECR; this has been discussed in part 1 of this 2 part article. This aim of this article was firstly, to review the literature in relation to the management of ECR and secondly, based on the available evidence, describe different strategies for the management of ECR. In cases where ECR is supracrestal, superficial and with limited circumferential spread, a surgical repair without root canal treatment is the preferred approach. With more extensive ECR lesions, vital pulp therapy or root canal treatment may also be indicated. Internal repair is indicated where there is limited resorptive damage to the external aspect of the tooth and/or where an external (surgical) approach is not possible due to the inaccessible nature of subcrestal ECR. In these cases, root canal treatment will also need to be carried out. Intentional reimplantation is indicated in cases where a surgical or internal approach is not practical. An atraumatic extraction technique and short extraoral period followed by 2-week splinting are important prognostic factors. Periodic reviews may be indicated in cases where active management is not pragmatic. Finally, extraction of the affected tooth may be the only option in untreatable cases where there are aesthetic, functional and/or symptomatic issues.

The comparative effectiveness and safety of three activated irrigation techniques in the isthmus area using a transparent tooth model.

AIM: To compare the effectiveness and safety of three activated irrigation techniques when removing pulp tissue from the isthmus of a transparent tooth model. The three techniques assessed were: the EndoVac (EV), passive ultrasonic irrigation (PUI) and ultrasonic wave aspiration (TUWA). Conventional syringe irrigation (CSI) was used as a control. METHODOLOGY: A transparent tooth model was created using the mesial root of an extracted mandibular first molar that had an isthmus and two independent mesial canals. An artificial 0.3-mL cylindrical chamber was created below the apical foramen. The tooth was then cleared. After preparation, the root canals were filled with fuchsine-stained bovine pulp tissue. The irrigation protocols were compared in respect of their effectiveness at removing pulp tissue from the isthmus and their safety with regard to irrigant extrusion. For all four groups, 5.25% sodium hypochlorite solution was used as the irrigant. Photographs were taken and analysed using an imaging software. A Kruskal-Wallis test was used to detect the differences between groups (statistical significance was set at P < 0.05). RESULTS: No group was associated with extrusion of irrigant beyond the apex. Significant differences were observed between the groups: TUWA was the most effective technique at removing pulp tissue from the isthmus (3.39 mm2 ; standard deviation (SD) = 0.67; range = 1.25-3.69), followed by PUI (2.16 mm2; SD = 0.38; range = 1.37-2.96), EV (0.73 mm2 ; SD = 0.14; range = 0.49-0.98) and CSI (0.27 mm2 ; SD = 0.01; range = 0.26-0.28). CONCLUSION: Ultrasonic wave aspiration was the most effective technique at removing artificial pulp tissue from the isthmus of a transparent tooth model. None of the techniques extruded irrigant.

The use of limited cone beam computed tomography in the diagnosis and management of a case of perforating internal root resorption.

AIM: To describe the use of cone beam computed tomography (CBCT) in the diagnosis and management of a maxillary lateral incisor with perforating internal root resorption (IRR). SUMMARY: Root resorption is the loss of dentine or cementum as a result of osteoclastic cell action. IRR occurs exclusively as a result of pulpal inflammation. Until very recently, the diagnosis of internal and external resorptive defects has been limited to the information obtained from conventional radiographic techniques. This case report describes the use of CBCT in the diagnosis and treatment planning of a case of perforating IRR. Emphasis is given to the modifications made to the treatment procedures in view of the additional information obtained from the CBCT data. KEY LEARNING POINTS: • Internal root resorptive defects may perforate the external root surface, and this may not be detectable using conventional radiographic techniques; consideration of this should be made during diagnosis and treatment planning. • CBCT provides additional relevant information on the location and nature of root resorptive defects when compared with that provided by conventional radiographs. • CBCT findings may modify treatment planning, as well as the techniques that may be employed during both non-surgical and surgical endodontic treatment.

The effectiveness of passive ultrasonic irrigation on intraradicular Enterococcus faecalis biofilms in extracted single-rooted human teeth.

AIM: To compare the efficacy of passive ultrasonic irrigation with 1% sodium hypochlorite, with that of conventional syringe irrigation with 1% sodium hypochlorite, on intraradicular Enterococcus faecalis biofilms in extracted single-rooted human teeth. METHODOLOGY: Biofilms of E. faecalis (strain OMGS 3202) were grown on the prepared root canal walls of 48 standardized root halves which had been longitudinally sectioned. Following reapproximation, the roots were divided into four groups of twelve. The two experimental groups were treated with conventional syringe irrigation with 1% sodium hypochlorite solution (experimental group A) and passive ultrasonic irrigation with 1% sodium hypochlorite solution (experimental group B). Of the two control groups, the first was treated with conventional syringe irrigation with sterile saline solution (control group C), whilst the second control group (D) received no irrigation. The root halves were processed for scanning electron microscopy. Three images (x 700), coronal, middle and apical, were taken of the twelve root halves in each of the four groups, using a standardized protocol. The images were randomized and biofilm coverage assessed independently by three calibrated examiners, using a four-point scoring system. RESULTS: There were no significant differences in the scores for remaining biofilm coverage between group A (conventional syringe irrigation with 1% sodium hypochlorite) and group B (passive ultrasonic irrigation with 1% sodium hypochlorite) at the three observed levels. There was a significant difference between both experimental groups (groups A and B) and group C (conventional syringe irrigation with sterile saline solution) (P < 0.001) at all three observed levels. CONCLUSIONS: Both conventional syringe irrigation and passive ultrasonic irrigation with 1% sodium hypochlorite were effective at completely removing intraradicular E. faecalis biofilms. Conventional syringe irrigation with sterile saline solution was only partially effective at removing the biofilms.