Etiology and Prevention of an Endodontic Iatrogenic Event: Instrument Fracture

Broken Instrument Removal Methods with a Minireview of the Literature

Instrument fracture in the root canal system is an unpleasant incident that may occur during root canal treatment. Comprehensive cleaning of the root canal system is often impossible in the presence of a broken instrument. Therefore, it is often imperative to remove the broken fragment from the root canal system. To date, various methods have been proposed for the removal of broken instruments from the root canal system. However, no consensus has been reached on a safe technique with a high success rate for broken instrument removal. This case series reports six cases of successful removal of broken instruments using different methods including the ultrasonic, tube-and-glue, tube-and-wire, tube-and-internal shaft, and the forceps techniques and also provides a brief review of the relevant literature.

Navigating Separated Instrument Retrieval: A Case Report

Instrument separation during endodontic therapy is a complication occurring in 2% to 6% of cases. Focusing on the Masserann technique, the study presents a success rate of 55% in retrieving separated instruments. The technique's effectiveness is demonstrated through a case involving retrieving an instrument from the mandibular first premolar. The technique utilizes various tools, including trephine burs and an extractor, providing a reliable means to dislodge tightly wedged fragments. Despite limitations in specific tooth types and the necessity for frequent radiographic monitoring, the Masserann kit proves effective and underscores the importance of attempting retrieval before considering surgical interventions. The presented case exemplifies the technique's clinical applicability and positive outcomes in intricate scenarios, emphasizing its significance in endodontic practice.

Incidence of fracture of ProDesign Logic system instruments: A cross-sectional retrospective study

The aim of the present study was to analyze the incidence of fracture of ProDesign Logic system instruments in endodontic treatments performed by a specialist, in addition to identifying the dental group, arch, and the root canal thirds in which the fractures occurred more frequently. Digital radiographs and medical records were initially analyzed and resulted in the selection of 561 teeth (1302 canals) treated between 2018 and 2020, using the ProDesign Logic system instruments. These data were reassessed to determine the occurrence of fractures and identify the dental group and root canal thirds in which they occurred. Then, the data were statistically analyzed using the Fisher's Exact Test (p < 0.05). The general fracture rates were 8.5 and 3.69%, considering the number of teeth and canals treated, respectively. Mandibular first molars were the teeth most associated with the occurrence of fractures (19.1%). When the arches were compared, there was no statistical difference regarding the number of fractures in the different root canal thirds (p = 0.307). However, they were more frequent in the apical third in both arches (p = 0.000). The incidence of fracture of ProDesign Logic system instruments was relatively high and occurred more frequently in the apical third of molars.

Quantitative Evaluation of Apically Extruded Debris in Root Canals prepared by Single-file Reciprocating and Single File Rotary Instrumentation Systems: A Comparative In vitro Study

BACKGROUND

Prevention of the debris from extruding to the periapical region is an important aspect to be taken care of as its extrusion can result in pain, periapical inflammation, and delayed healing owing to the presence of highly infective components in the debris.

AIM

The present trial was aimed to compare and assess the amount of debris extruded apically using the single-file reciprocating system - WaveOne GOLD and single file rotary system - OneShape in root canal preparations in vitro.

MATERIALS AND METHODS

Thirty mandibular premolars were divided into two groups (15 samples each) prepared with a single-file reciprocating system - WaveOne GOLD and single-file rotary system - OneShape. Debris extruded was collected and then stored in an incubator. The final weight was calculated after obtaining the mean of three consecutive weights obtained for each tooth. The data were compared using the ANOVA and Turkey's post hoc analysis.

RESULTS

Debris extrusions were recorded in both groups and analysis revealed statistical differences in weight before and after the instrumentation procedures in both groups. When compared, reciprocating single file - WaveOne GOLD extruded more debris than rotary single file system - OneShape with a P < 0.001.

CONCLUSIONS

The rotary instrumentation systems extrude lesser debris apically than the reciprocating instrumentation system. The difference found was statistically significant.

Techniques to address fractured instruments in the middle or apical third of the root canal in human permanent teeth: a systematic review of the in vitro studies

OBJECTIVE

The objective of this study is to investigate techniques for approaching fractured instruments in the root canal and to present possible outcomes in relation to dentin thickness, fracture resistance, technique success, and clinical time.

MATERIALS AND METHODS

The bibliographic research was carried out in PubMed, Cochrane, Lilacs, Web of Science, Scopus, grey literature, and manual search. Following the inclusion and exclusion criteria, the titles and abstracts of 506 articles were read. Of these, 60 articles were selected and read in full. Fourteen articles were included in this systematic review.

RESULTS

The most studied technique was the ultrasonic technique and obtained good general results. The more apically the instrument is located, the more difficult it is to remove, the more dentin is removed, and the lower the fracture resistance of the tooth. When removal is not possible, the bypass technique can be performed (bypassing), and on weakened teeth or with little dental remnants, the GentleWave System technique can be used.

CONCLUSION

This systematic review shows the evidence from laboratory studies that the curvature and the root third in which the fracture of instruments occurred is relevant to fracture resistance and success. The ultrasonic technique got the best results. Well-conducted clinical studies should be performed for clinical practice.

CLINICAL RELEVANCE

The approach of fractured instruments in the root canal is efficient with the use of ultrasound, bypass technique, and Gentle Wave System.

Effectiveness of XP-Endo Finisher and passive ultrasonic irrigation on intracanal medicament removal from root canals: a systematic review and meta-analysis

Background

XP-Endo Finisher (XPF) and passive ultrasonic irrigation (PUI) are commonly used in intracanal medicament removal. The effectiveness of these two techniques needs to be compared, and evidence-based research should be conducted.

Methods

A comprehensive literature search was conducted in PubMed, Web of Science, Embase, Cochrane Library, and Google Scholar up to December 20th, 2020. The outcomes of the included trials were pooled into the Cochrane Collaboration’s Review Manager 5.3 software. Cochrane’s risk-of-bias tool 2.0 was applied to assess the risk of bias.

Results

Nine articles were included in this systematic review and processed for data extraction, and eight studies were identified for meta-analysis. In general, the use of PUI showed better medicament removal effectiveness than XPF (odds ratio [OR]: 3.09; 95% confidence interval [CI], 1.96–4.86; P < 0.001). PUI was also significantly more efficient than XPF in the apical third (OR: 3.42; 95% CI, 1.32–8.84; P = 0.01). For trials using sodium hypochlorite (NaOCl) alone, PUI was also significantly more effective than XPF on intracanal medicaments removal (OR: 5.23; 95% CI, 2.79–9.82; P < 0.001). However, there was no significant difference between PUI and XPF when NaOCl and ethylenediaminetetraacetic acid (EDTA) were used in combination (OR: 1.51; 95% CI, 0.74–3.09; P = 0.26). In addition, for studies whose intracanal medicament periods were two weeks, the effectiveness of PUI was statistically better than the XPF (OR: 7.73; 95% CI, 3.71–16.07; P < 0.001). Nevertheless, for trials whose intracanal medicament time was one week or over two weeks, no differences between the XPF and PUI were found (OR: 1.54; 95% CI, 0.74–3.22; P = 0.25) (OR: 1.42; 95% CI, 0.44–4.61; P = 0.56).

Conclusions

The meta-analysis is the first study to quantitatively compare the effectiveness of XPF and PUI techniques on intracanal medicaments removal. With rigorous eligibility criteria, the study only included high-quality randomised controlled trials. The study indicated that PUI might be superior over XPF techniques for removing intracanal medicaments from artificial standardized grooves and cavities in the root canal system. The anatomical areas, irrigation protocol, and intracanal medicaments time may influence the cleaning efficacy.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12903-021-01644-7.