Roland Weiger

Objectives: This study compared conventional access cavity preparation (CONV) and real-time guided endodontics (RTGE) in teeth with pulp canal calcification (PCC) regarding the rate of detected root canals, substance loss and procedural time. Materials and methods: A total of 72 extracted, sound human teeth (48 incisors, 24 canines) with PCC were matched in pairs, divided into two groups of 36 teeth each. An endodontic specialist performed CONV, while a general dentist not specialized in endodontics utilized RTGE on six models each, under simulated clinical conditions. The operators recorded the time to access the calcified root canals. Pre- and postoperative cone-beam computed tomography (CBCT) scans were obtained to measure substance loss. Statistical significance was tested by examining the overlap of 95% confidence intervals (CIs) and Fisher’s exact test. Results: RTGE had a marginally higher success rate (34/36) in detecting root canals compared to CONV (32/36) (p =.67). While RTGE resulted in less substance loss (CI: 9–14.3 mm³ vs. 15–24.2 mm³), it required more procedural time than CONV (CI: 11.6–17.8 min vs. 1.4–2.5 min). Conclusions: Both CONV by a specialist and RTGE by a general dentist achieved a high detection rate of root canals, with RTGE resulting in superior tooth substance preservation but at the expense of longer operation times. Clinical relevance: RTGE can be considered as an alternative technique for non-specialists when treating teeth with PCC, emphasizing procedural safety and effective canal detection.

Background: To compare the outcomes of conventional access cavity preparation (CONV) versus guided endodontics (GE) for access cavity preparation in anterior teeth with pulp canal calcification (PCC) regarding root canal detection, substance loss, procedural time, and need for additional radiographs. Methods: Extracted, sound human teeth with PCC (n = 108) were matched in pairs, divided into two groups and used to produce 18 models. An independent endodontist and a general dentist performed access cavity preparation under simulated clinical conditions on nine models each (54 teeth). The endodontist used the conventional technique and the general dentist GE. Time needed to access the root canals and the number of additional radiographs were recorded. Pre- and postoperative cone-beam computed tomography scans were obtained to measure substance loss. Statistical significance was tested by examining the overlap of 95% confidence intervals (CIs) between the groups. Results: All root canals were successfully accessed by both methods. There were no significant differences in substance loss (CI: CONV 15.9–29.6 mm³ vs. GE 17.6-27.5mm³) or procedural time (CI: CONV 163.3-248.5 s vs. GE 231.9-326.8 s). However, 31 additional radiographs were required for GE compared to none for CONV. Conclusions: For access cavity preparation in teeth with PCC, both CONV by a specialist and GE by a general dentist produce good results in terms of substance loss and time requirements.

The purpose of this ex vivo study was to determine the accuracy of template-based guided endodontics for access cavity preparation and root canal detection in posterior teeth. First, three maxillary and four mandibular models were constructed using 67 premolars and molars, with a total number of 135 main root canals. Cone beam computed tomography (CBCT) and three-dimensional 3D surface scans of each model were performed and matched in order to plan access cavity preparation and design templates virtually. Template-guided access cavity preparation was then performed for each tooth, followed by postoperative CBCT scanning. Deviations between planned and prepared access cavities were measured after superimposition of the pre- and postoperative CBCT scans, and they were analyzed using descriptive and multivariate statistics. All root canals (135/135) were detected utilizing guided endodontics. The mean angle deviation was 1.4 degrees, and the mean deviations at the tip and base of the bur were 0.24–0.31 mm and 0.26–0.29 mm, respectively. This study demonstrated that guided endodontics is an accurate and predictable method for endodontic access cavity preparation in posterior teeth.

Distinguishing composite remnants from tooth structure after trauma splint removal can be challenging. This study aimed to compare the Fluorescence-aided Identification Technique (FIT) with conventional light illumination (CONV) in terms of accuracy and time required for the detection of composite remnants after trauma splint removal. Ten bovine tooth models containing anterior teeth from 12 to 22 with composite remnants after trauma splint removal were used. These models were examined by 10 students and 10 general dentists. Each examiner assessed the 10 models using CONV or FIT three times with an interval of 2 weeks each using a prototype fluorescence-inducing headlamp with a spectral bandwidth of (405 ± 7) nm for FIT and a dental unit lamp for CONV. The examiners charted the location of identified composite remnants, and the procedure time needed for each method was recorded. Statistical analysis was performed with R 3.2.2 software with a significance level of α = 5%. FIT was more accurate and less time-consuming than CONV (p < 0.001). There were no significant differences between dentists and students concerning accuracy (CONV: p = 0.26; FIT: p = 0.73). Students performed FIT significantly faster than the dentists (p < 0.001). FIT is a quick and reliable method of identifying composite remnants after trauma splint removal.

Externe zervikale invasive Resorptionen (ECR) treten selten auf. In jedem Fall stellen sie sowohl diagnostisch als auch therapeutisch eine Herausforderung für den Zahnarzt dar. Zumeist handelt es sich um einen Zufallsbefund, z. B. im Rahmen der Anfertigung eines Röntgenstatus oder von Bissflügelaufnahmen. Die Abgrenzung zu einer internen, von der Pulpa ausgehenden Resorption sowie die detaillierte Beurteilung, ob der betroffene Zahn erhalten werden kann, gelingt zuverlässig nur mit der 3-dimensionalen Darstellung des Defekts mittels digitaler Volumentomografie (DVT). Neben dem Ausmaß des resorbierten Wurzeldentins bestimmen die Größe und die Lage der externen Eintrittspforte, von der die Resorption initial ausging, die therapeutischen Optionen. Diese schließen im Wesentlichen die Entfernung des eingedrungenen Gewebes über eine erweiterte Zugangskavität via Wurzelkanalsystem, die chirurgische Defektdarstellung oder die Kombination beider Methoden ein. In ausgesuchten Fällen stellt die intentionelle Replantation eine valide Alternative dar. Publication Date: 17 December 2021 (online) © 2021. Thieme. All rights reserved. Georg Thieme Verlag KG Rüdigerstraße 14, 70469 Stuttgart, Germany

This in vitro study aimed to evaluate apical pressure during irrigant delivery with syringe irrigation in immature teeth with an open apical foramen. Conventional syringe irrigation was performed in a 3D-printed immature incisor. A 5 mL syringe combined with 25 G and 30 G cannulas was used. Open-ended and side-vented needle tip designs were assessed. Cannulas were placed at tooth length (TL), TL −1 mm, TL −2 mm, and TL −4 mm. The syringe plunger was moved with a force of 10 N, 20 N, 40 N, and 80 N to simulate clinical conditions. A pressure sensor measured periapical pressures during irrigation. Each experiment was repeated 10 times. Data were analyzed descriptively (maximum, mean, standard deviation, 95% CI) with the critical threshold indicative of extrusion set at 7.64 mbar. 30 G cannulas with both needle tip designs never exceeded the threshold at any TL with a plunger force of 10–40 N. At 80 N, 30 G open-ended cannulas exceeded the threshold in 10%, 30 G side-vented in 20–60% of the measurements. At any TL, 25 G open-ended cannulas and 25 G side-vented cannulas never crossed the threshold with forces of 10–20 N and 10 N, respectively. Consequently, 30 G cannulas with both designs can be recommended for irrigant delivery in immature teeth. 25 G cannulas ought to be used with caution.