No abstract

This study underscores the need to thoroughly examine all CBCT volumes for clinically significant findings within and beyond the region of interest.

It is not known to what extent residual infection may interfere with the success of pulp regeneration procedures. The aim of this study was to determine, radiographically and histologically, the effect of residual bacteria on the outcome of pulp regeneration mediated by a tissue-engineered construct as compared with traditional revascularization. Periapical lesions were induced in 24 canine teeth of 6 ferrets. After disinfection with 1.25% NaOCl and triple antibiotic paste, ferret dental pulp stem cells, encapsulated in a hydrogel scaffold, were injected into half the experimental teeth. The other half were treated with the traditional revascularization protocol with a blood clot scaffold. After 3 mo, block sections of the canine teeth were imaged radiographically and processed for histologic and histobacteriologic analyses. Associations between variables of interest were evaluated through mixed effects regression models. There were no significant differences between the 2 experimental groups in radiographic root development ( P > 0.05). There was a significant association between the presence of persistent periapical radiolucency and root wall thickness ( P = 0.02). There was also no significant difference in histologic findings between the 2 experimental groups ( P > 0.05). The presence of residual bacteria was significantly associated with lack of radiographic growth ( P < 0.001). The amount of dentin-associated mineralized tissue formed in teeth with residual bacteria was significantly less than in teeth with no residual bacteria ( P < 0.001). Residual bacteria have a critical negative effect on the outcome of regenerative endodontic procedures.

No abstract

No abstract

No abstract

No abstract

Aim To determine and compare the accuracy and efficiency of a dynamic navigation system (DNS) with a freehand (FH) technique when conducting root-end resection in a human cadaver model. Methodology Forty roots in cadaver heads were included and divided into two groups: DNS (n = 20) and FH (n = 20). Cone beam computed tomography (CBCT) scans of all teeth were taken. The drilling path and depth were planned virtually to using the Xguide software (X-Nav Technologies, Lansdale, PA, USA). Osteotomy and root-end resection were done under navigation in the DNS group, and freehand under the dental operating microscope in the FH group. Post-operative CBCTs were taken. Linear deviations, angular deflection, time of operation and number of mishaps were compared with determine the accuracy and efficiency. Shapiro-Wilk, one-way ANOVA and Fisher exact tests were used (P < 0.05).Results Linear deviations, angular deflection and operation time were significantly less in the DNS group (P < 0.05). The number of mishaps was not different between the two groups (P > 0.05). Subgroup analyses revealed that the distance of >5 mm from buccal cortical plate was significantly associated with lower accuracy, increased operation time and greater incidence of mishaps in the FH group (P < 0.05), but not in the DNS group. Conclusions The dynamic navigation system was more accurate and more efficient in root-end resection in a cadaver model than the freehand technique. The distance of the roots from the buccal cortical plate had a significant negative impact on the accuracy and efficacy of the root-end resection procedure when using the freehand technique. The dynamic navigation system has the potential to be a safe and reliable technological addition to endodontic microsurgery.