Simplify pulpectomy in primary molars with a single-file reciprocating system: a randomized controlled clinical trial

Cauterization of Narrow Root Canals Untouched by Instruments by High-Frequency Current

The mechanical removal of bacteria is fundamental to the treatment of infected root canals, but complete sterilization of biofilms tends not to extend to uninstrumented areas. However, during electrical conduction to a root canal filled with a conductor, the higher impedance where the root canal is narrower generates Joule heat that may result in a large temperature increase and sterilization. The effect of a high-frequency electric current on the wall of a simulated narrow root canal was investigated by scanning electron microscopy (SEM) and energy dispersive X-ray spectrometry (EDS). Simulated root canals, 0.1 mm in diameter, were prepared in dentine blocks. The root canal wall was treated with Plank-Rychlo solution for 5 min to create a decalcified layer. The simulated root canal was filled with either saline or NaClO, and 150 or 225 V at 520 kHz was applied for 0 s, 1 s, or 5 s. As the conduction time increased, and when the saline was replaced with NaClO, the proportion with a flat decalcified surface decreased, dentinal tubules and a lava-like morphology were significantly more evident on SEM (p < 0.01), and EDS showed significant decreases in carbon and oxygen and increases in calcium (p < 0.01). It was concluded that filling uninstrumented root canals with NaClO and using electrical conduction for 5 s could incinerate and eliminate the organic material of the root canal wall. The application of high-frequency electric current may lead to the cure of many cases of persistent apical periodontitis.

Effect on undergraduate student self-confidence in using 3D printed primary molars for root canal treatment simulation training

PURPOSE

The main purpose of this study was to assess the effect of a root canal treatment (RCT) practical simulation-based session using 3D printed primary molars on the self-confidence of fourth-year undergraduate dental students. Our study was also designed to explore student experiences with both manual and rotary RCT procedures and to investigate the association between the self-confidence in undertaking an RCT and the quality of the RCT.

METHODS

Student global self-confidence in undertaking an RCT on a healthy, cooperative child aged 4-5 years was evaluated 2 h before, 1 month after, and 11 months after the simulation training session. Once each instrumental procedure had been completed, the students were also asked to score the level of confidence (specific self-confidence) they felt regarding the use of RP and MP. After each training session, the quality of the RCT was radiographically evaluated by two trained, independent investigators.

RESULTS

Overall, student global self-confidence in undertaking an RCT increased significantly immediately after the practical session and remained stable for the ensuing eleven months. The students declared a clear preference for RP and were more self-confident in undertaking an RCT after RP than after MP. The proportion of RCTs considered of good quality was the same for the manual (31.5%) and rotary (30.3%) procedures.

CONCLUSIONS

Simulation training is a good way to train dental students who are confident in undertaking RCTs. However, confidence is not directly related to competence. Teachers should be encouraged to develop a comprehensive simulation training program, including feedback, debriefing, and repetitions.

Reciprocating instrumentation for endodontic treatment of primary molars: 24-month randomized clinical trial

BACKGROUND

Although reciprocating instrumentation has been extensively studied for permanent teeth, stronger evidence for its use in primary teeth is lacking.

AIM

The aim of this randomized clinical trial was to compare the efficacy of endodontic treatment in primary molars using reciprocating (RECIP) and manual (MAN) instrumentation techniques after 24 months.

DESIGN

Primary molars with indication of endodontic treatment were randomly divided into two groups: MAN and RECIP. Treatments were performed, and root canals were filled with calcium hydroxide and iodoform paste. Teeth were later restored with bulk-fill composite resin and re-evaluated after 6, 12, 18, and 24 months. The primary outcome was the success of the endodontic treatment evaluated by Cox regression analysis adjusted by cluster and success rate after 24 months in the intention-to-treat (ITT) population. Instrumentation time, discomfort, postoperative pain, and quality of root canal filling were also evaluated as secondary endpoints.

RESULTS

A total of 151 primary win 107 children were included, and 137 were followed up for 24 months. Success rate of teeth allocated to the MAN group was 57.3% and 55.3% for RECIP (p = .792); MAN instrumentation, however, was more time-consuming (p = .005).

CONCLUSION

The efficacy of endodontic treatment in primary molars using reciprocating and manual instrumentation is similar after 24 months.

Update in the Diagnosis and Treatment of Root Canal Therapy in Temporary Dentition through Different Rotatory Systems: A Systematic Review

The need to perform fast, effective and efficient pulpectomies has led to the development of numerous valid rotary systems. Its technical features allow the clinician to obtain good results in less working time. The objective of this study is to compare the characteristics of the different current rotary systems to favor a correct diagnosis and subsequent treatment. A systematic review of the literature has been carried out in accordance with the PRISMA recommendations. A search was carried out in PubMed, Embase Scopus, Cochrane and Web of Science databases, and was completed with a manual search. The following variables were extracted from the selected studies: author, year, sample, rotary systems used (length, diameter, taper, speed), obturation material and irrigant. From the initial electronic search of the five databases, 315 articles were identified. Once the duplicate articles were eliminated, a total of 233 remained. After reading both title and abstract, 200 articles were eliminated, leaving 33. On account of reading the full text, 22 were eliminated for not answering the research question or the inclusion criteria, leaving a total of 11 articles for the systematic review. Rotary systems which are able to adapt to the root anatomy of primary teeth and allow rapid and simple instrumentation, without producing excessive extrusion of debris at the root apex, will be the ones that provide the best results to the pediatric dentist during the performance of pulp treatment in primary teeth. Clinical success will only be achieved through proper prior diagnosis.

Postoperative pain after primary molar pulpectomy using rotary or reciprocating single files: A superior, parallel, randomized clinical trial

AIM

To compare postoperative pain intensity between two single-file systems with different kinetics (the OneShape file with continuous rotation vs. the WaveOne Gold file with reciprocation movement) after primary molar pulpectomy.

DESIGN

This superiority, parallel, randomized clinical trial included 164 healthy children aged 6 to 8 years with asymptomatic, necrotic, maxillary primary second molars due to caries. An equal number of children were assigned to the two groups. The teeth of children in Group 1 were instrumented with the OneShape rotary system (Micro-Mega), whereas teeth of children in Group 2 were instrumented with the WaveOne Gold reciprocating system (Dentsply Maillefer). Postoperative pain intensity was assessed using a 4-point pain scale at 6, 12, 24, 48 and 72 h and 1 week after treatment. The parent of each participant received 6 flashcards that included four faces and a word describing each face. A chi-square test was used to compare postoperative pain intensity. The level of significance was set to 5%.

RESULTS

Over the follow-up period, no significant difference in postoperative pain intensity was found between the two groups (p > .05). Although the absolute risk reduction maximum limit of 95% CI equal or exceeded the predetermined proportional difference of 0.15, pain intensity was inconclusive at 6, 24, and 48 hours denoting that the superiority of the OneShape single-file over the WaveOne Gold single-file could not be declared.

CONCLUSIONS

Postoperative pain intensity associated with a rotary vs. reciprocating file system was nearly similar.

Are electronic apex locators accurate in determining working length in primary teeth pulpectomies? A systematic review and meta-analysis of clinical studies

BACKGROUND

The lack of a well-defined apical constriction in primary teeth raises concerns regarding the accuracy of electronic apex locators (EALs) for measuring working length.

OBJECTIVES

To evaluate the accuracy of EALs in determining working length in primary teeth pulpectomies.

METHODS

Two reviewers searched ten databases up to September 2021. Clinical studies evaluating the accuracy of the electronic measurement of working length in primary teeth pulpectomies were included. Studies without a comparison group, with samples smaller than ten root canals, and that did not use a multiple frequency EAL were excluded. A meta-analysis was conducted to assess the paired differences in mean lengths between measurements obtained by electronic and comparative methods. In addition, a meta-analysis of proportion was applied according to the level of difference between the measures. The risk of bias and applicability of the studies were assessed using the QUADAS-2 tool. The certainty of evidence was assessed with the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) approach.

RESULTS

Twenty-nine studies were included in the qualitative analysis and twenty-three in the quantitative analysis. The methods of comparison for the electronic measurement were the radiographic method, radiovisiographic, scanning electron microscopy, and direct visualization. The meta-analysis showed that the electronic measurement tends to be shorter than radiographic measurement, while the other methods showed no difference. The proportion analysis showed a higher pooled proportion of difference values between electronic and comparative measurements within -0.5 to +0.5 mm (69.31%). The certainty of the evidence suggested very low confidence in estimating the outcome.

DISCUSSION

The results of this review denote a good performance of the EALs in determining working length in primary teeth pulpectomies. However, these results are based on clinical studies with low methodological quality and high heterogeneity, which require careful interpretation for clinical practice.

CONCLUSIONS

Although the results suggest acceptable accuracy of EALs in determining working length in primary teeth pulpectomies, the low quality of the included studies and the very low certainty of the evidence require clinicians to interpret these results with caution. More robust evidence is required to support that these devices are accurate for primary teeth.

Micro-CT evaluation of 'danger zone' and microcrack formation in mesial root canals of primary teeth with single-file rotary and reciprocating systems

BACKGROUND

Although single-file rotary systems are accepted in the field of paediatric dentistry in terms of providing time advantage, research works continue due to the variable anatomical structure of the root canal.

AIM

This study aimed to evaluate rotary systems in different kinematics in terms of microcracks and the shaping of the danger zone in primary molars by micro-CT.

DESIGN

The mesial canals of primary molars (n = 30) were used. Root canals in each group (n = 10) were prepared with single-file rotary systems (One Shape®, OS; XP-endo® Shaper, XP-ES; WaveOne Gold, WOG). The images were evaluated for dentin thickness in the danger zone and microcrack formation.

RESULTS

WOG caused the highest dentin reduction in the danger zone area. OS led to significantly less dentin reduction than XP-ES and WOG (P < .05). The XP-ES showed the highest number of microcracks (P < .05). No statistically significant difference was found between WOG and OS (P > .05). In all systems, more microcracks were observed in the middle third than coronal and apical.

CONCLUSION

Within the limitations of this study, the rotary systems were superior to reciprocating in terms of shaping ability in the danger zone. It is thought that further studies with different systems should be designed considering the anatomical variations and chemical composition of primary teeth.

Clinical differences of hand and rotary instrumentations during biomechanical preparation in primary teeth-A systematic review and meta-analysis

BACKGROUND

The hand and rotary instruments are used for cleaning and shaping of root canals during biomechanical preparation in primary teeth.

AIM

To determine clinical differences of hand versus rotary root canal instrumentation in primary teeth.

DESIGN

Comprehensive searches were made in four electronic databases [MEDLINE (via PubMed), EMBASE, Google Scholar, and The Cochrane Central Register of Controlled Trials] till March 2020, and prospective studies that met the inclusion criteria were included. The primary outcome was instrumentation time, whereas the secondary outcomes were quality of obturation, obturation time, and clinical and radiographic success. From 604 screened studies, eleven studies qualified for meta-analysis. The random-effect model and generic inverse variance approach were used for meta-analysis.

RESULTS

There was significant decrease in instrumentation time [MD-5.00 minutes (95% CI: 3.05-6.94), P < .00001, moderate evidence quality] and obturation time [MD-0.43 minutes (95% CI: 0.15-0.71), P = .003, low evidence quality] with rotary instrumentation. Optimal quality of obturation was achieved in significantly more number of teeth [risk ratio (RR) = 0.71(95% CI: 0.53-0.95),P = .02, moderate to high evidence quality] with rotary instrumentation. Similar clinical and radiographic success was observed in hand and rotary instrumentation techniques.

CONCLUSION

Significant reduction in instrumentation time of five minutes was observed using rotary instrumentation with moderate quality evidence.