Influence of foraminal enlargement on the apical extrusion of filling material: Volumetric analysis using micro‐computed tomography

How Does Intentional Apical Foraminal Enlargement Affect the Foramen and Root Canal Morphology?

INTRODUCTION

This study assessed the effect of intentional foraminal enlargement on the foramen and the apical root canal morphology.

METHOD

Sixty mesial roots of mandibular molars were scanned by micro-computed tomography. Their apical foramina were photographed with a stereomicroscope before and after preparation. Three groups were formed (n = 20) according to the working length (WL). G-1: foramen - 1 mm; G0: foramen; and G+1: foramen + 1 mm. Each group originated 2 subgroups (n = 10): G-1: Buchanan's patency (size 10 K-type file) and foraminal debridement (sizes 20, 25 and 30 K-type files); G0 and G+1: rotary foraminal enlargement (ProDesign S size 25/.08) or reciprocating foraminal enlargement (R25). The area, perimeter, transportation, and noninstrumented walls of the foramen were evaluated. The root canal transportation and the centering index of preparation at 1, 3 and 5 mm from the foramen were also assessed. Data were compared statistically (α = 5%).

RESULTS

The instruments used at the foramen and 1 mm beyond promoted foraminal enlargement and transportation. Regarding NIW, there was no difference between mechanized foraminal enlargements performed at the foramen or 1 mm beyond, similar to the manual foraminal debridement group (P > .05). There was no difference in transportation and centralization at 1-, 3-, and 5-mm apical levels, regardless of the instrumentation systems.

CONCLUSION

Mechanical preparation at the foramen, or 1 mm beyond, resulted in foraminal enlargement, transportation and were not able to touch all root canal walls that delimit the foramen.

Outcome of root canal treatment of teeth with chronic apical periodontitis treated with foraminal enlargement and 2% chlorhexidine gel: a retrospective cohort study

INTRODUCTION

This retrospective cohort study aimed to estimate the success rate (SR) of primary root canal treatment on teeth with a diagnosis of pulp necrosis (PN) and asymptomatic apical periodontitis (AAP) when using 2% chlorhexidine gel as an auxiliary chemical substance (ACS) and foraminal enlargement instrumentation technique.

METHODS

This study evaluated 178 patients with 206 teeth submitted to primary root canal treatment performed by graduate residents in endodontics. The inclusion criteria were patients who underwent treatment over a period of 1 to 7 years on teeth with a diagnosis of PN and AAP. The SR was evaluated clinically and radiographically and categorized considering strict' (complete resolution of periradicular lesion) or 'loose' (reduction in the size of existing periradicular lesion) criteria. Cases of clinical and/or radiographical absence of repair were classified as a failure. Two calibrated examiners independently assessed treatment outcomes using the ImageJ software.

RESULTS

The SR were 81.1% (95% CI: 75.7% - 86.4%) and 87.4% (95% CI: 82.8% - 91.9%) when considering the 'strict' or 'loose' criteria, respectively. Females had a higher SR when strict criteria were applied. Also, the SR was significantly reduced when there was an increase in the patient's age.

CONCLUSION

Within the limitations of this study, it was found that teeth with a diagnosis of PN and AAP and treated associating the use of 2% chlorhexidine gel and foraminal enlargement achieved substantial SR. Gender and age were prognostic factors that played a significant role in the SR. Future randomized controlled trials should further investigate the effects of foraminal enlargement and 2% chlorhexidine gel as an ACS.

Cavernous sinus thrombosis followed by brain ischaemia in a type-1 diabetic patient: a persistent endodontic infection report

Central nervous system infections and cavernous sinus thrombosis are associated with high mortality rates and may be a consequence of oral infection propagation. A 24-year-old woman has attended a private dental office with a pain complaint in the upper right central incisor and had the endodontic treatment completed. However, the patient returned to the dental office reporting pain in the same tooth and the presence of swelling. Then, the root canal was retreated. After one week, the patient presented to a Basic Health Unit with a history of vomiting and convulsion crisis followed by loss of consciousness. A computed tomography exam showed cavernous sinus thrombosis and brain ischaemic areas. The present report describes a rare case of cavernous sinus thrombosis followed by brain ischaemia in a type-1 diabetic patient, associated with persistent endodontic infection, with subsequent patient's death.

Endodontic postoperative flare-up: An update

Endodontic treatment corresponds to a combined chemical and mechanical approach, followed by a three dimensional hermetic obturation, that eliminate the pulpal and periradiculare disease and boost healing and repair of periradiculare tissue. Despite the advances in the endodontic field, the inter-appointment flare up remains a true nightmare that encounters every dentist. This complication commences a few hours or days after root canal procedures and it is characterized by the development of pain and/or swelling, requiring an unscheduled appointment for emergency treatment. Different studies showed that flare-ups represent a multifactorial phenomenon including mechanical, chemical and microbial factors. In addition, a correlation was found between flare-up and age, gender, tooth type, presence of preoperative pain, tooth condition before treatment, irrigation techniques, number of visits as well as intracanal medication. Moreover, some medicine intake was proved to be efficient in controlling this postoperative pain. However, a clear procedure to avoid its occurrence is yet to be established. In this review, we summarize knowledge about the etiology of flare-up and its related factors. This could be effective in helping dentists to adapt some strategies to prevent it.

Analysis of Instrumentation Protocols Regarding the Quality of Mesial Canal Preparation in Mandibular Molars: A Micro-computed Tomographic Study

INTRODUCTION

This study aimed to use micro-computed tomographic imaging to analyze the quality of the endodontic preparation of mesial canals in mandibular molars provided by 3 instrumentation protocols.

METHODS

Forty-five extracted mandibular molars with 2 independent mesial canals were selected, and the initial micro-computed tomographic imaging was performed. The initial volume values of the canals were submitted to statistical analysis for paired division. The groups were determined according to the final enlargement of the canal and the working length adopted (ie, G25.06/+1 mm, G35.05/foramen, and G50.01/-1 mm). At the end of each instrumentation sequence, the root canals were scanned and analyzed with regard to the increase in the total and apical volume, centralization, and preparation transportation and the percentage of the total and apical uninstrumented walls.

RESULTS

For the intragroup comparison, the Wilcoxon test was used, and for the intergroup analysis, the Kruskal-Wallis and Dunn tests were used (P < .05). In the analysis of the canal total volume, a statistical difference was found between G25.06/+1 mm and the remaining groups (P < .05). In the apical third, a statistical difference was observed between G25.06/+1 mm and G50.01/-1 mm (P < .05). No statistical difference was found between the groups in terms of centralization and transportation of the preparation or in terms of the percentage of the total or apical uninstrumented walls.

CONCLUSIONS

The preparation of the mesial canals of mandibular molars up to larger tip files but with a lower taper at 1 mm before the foramen resulted in a larger volume of apical preparation, kept the preparation centralized, and provided safe apical dentin wear without excessive cervical wear.