Traditional and Conservative Molar Endodontic Access Cavity Designs: A Classification and Overview

Minimally invasive endodontics' specific focus on dentine preservation is gaining popularity. Before deciding on the appropriate endodontic access cavity design, clinicians should investigate the advantages and disadvantages associated with different treatment modalities. The purpose of this article is to provide a summary of possible advantages and disadvantages of different endodontic access cavity designs with the focus on traditional, conservative and ultra-conservative endodontic access cavities, specifically in molar teeth. No conclusive evidence is found in the literature favouring one access cavity design above another and clinicians are advised to evaluate each case individually when deciding on the appropriate access cavity design for that specific case. Fracture resistance, proper shaping in order to facilitate irrigation and disinfection, as well as canal location and orifice detection are some of the contributing factors in selecting an appropriate access cavity design that will be highlighted in this article

Fracture of endodontic instruments - Part 1: Literature review on factors that influence instrument breakage

Instrument fracture is a serious complication during endodontic treatment of teeth, having an adverse effect on the outcome of the nickel titanium (NiTi) treatment, especially if the fracture prevents apical access to the infected root canal. Despite the advent of NiTi files, the risk of fracture during the endodontic preparation of root canals, especially in severely curved canals, remains a serious concern. The fracture of NiTi files during preparation may result in a compromised prognosis for the tooth. In the presence of periapical lesions, instrument fracture may reduce the chances of successful healing

A comparison of failure rates and canal preparation times between WaveOne Gold and One Curve file systems with and without glide path preparation in simulated canals

The aim of this study was to compare the failure rate and canal preparation times of the Primary WaveOne Gold file (Dentsply Sirona, Ballaigues, Switzerland) with the One Curve file (Micro Méga, Besançon, France). The influence of glide path preparation on failure rate and final preparation times were also evaluated. Endo training blocks (Dentsply Sirona) with simulated canals were separated into four groups: Group 1: Primary WaveOne Gold with WaveOne Gold Glider; Group 2: Primary WaveOne Gold without glide path; Group 3: One Curve with One G; Group 4: One Curve without glide path. The number of training blocks that were shaped before instrument fracture occurred was recorded. Glide path and final preparation times were also recorded. Where no glide path was prepared, One Curve file prepared a significantly higher number of canals (14.33± 0.58) than the Primary WaveOne Gold (4.6 ± 1.34) before instrument fracture occurred (p<0.001). The One Curve with One G Glide Path file prepared significantly higher number of simulated canals (28±1.41) than the Primary WaveOne Gold with WaveOne Gold Glider (15 ± 1.41) before instrument fracture (p<0.001). Glide path preparation times with WaveOne Gold Glider (4.8s) were significantly faster compared to the One G Glide Path file (7.29s)(p<0 .001). Significantly faster final canal preparation times were achieved in groups where glide path were prepared (p<0.001). One Curve files exhibits a greater fracture resistance than Primary WaveOne Gold files. Glide path preparation increases the longevity of preparation files and results in faster final canal preparation

Pulpotomy: An alternative treatment modality to conventional root canal treatment

Vital pulp therapy is considered a successful treatment modality in primary and immature permanent teeth. The development of bioactive material has led to vital pulp therapy and pulpotomy treatment becoming a popular treatment modality in permanent teeth. This literature review investigates pulpotomy procedures on permanent teeth as a viable option, as opposed to conventional root canal treatment, as presented in the case report included.Aim The aim of this study is to evaluate literature on the reported success of pulpotomy treatment in mature permanent teeth. For this reason, the study specifically reviewed literature detailing the use of pulpotomies including the materials required for the procedure.MethodThe literature review is focused on studies using MTA and bioactive alternatives as pulpotomy material. An electronic search was done on EBSCOhost to source 58 articles published from 1979 to 2022. Results Literature investigated reports that pulpotomy treatment with bioactive materials shows promising results and therefore the possibility exists of it being a suitable treatment option or alternative to conventional root canal treatment

Modern considerations when approaching fractured endodontic instruments - Part 2: A review of the literature and clinical techniques

Once root canal treatment is considered, the treating clinicians must be aware of the real possibility that complications and unforeseen accidents can occur during any stage of the treatment. Complications and accidents may include instrument separation, root perforation on different levels and ledge formation

Root and canal morphology of the mandibular first molar: A micro-computed tomography-focused observation of literature with illustrative cases. Part 1: External root morphology

The mandibular first molar often requires endodontic intervention, which can be challenging and complex with several variants in the number of canals and roots. Usually, these teeth have a single mesial and distal root, but variants and anomalies have been noted. The incidence of the number of roots can differ between populations. For instance, up to a third of East Asians present with a third root, while the global prevalence is 8.9%. One- and four-rooted first molar teeth are seldom encountered. Over the years different methods have been used to study root and canal morphology, but micro-computed tomography (micro-CT) has provided a non-invasive method to study root and canal morphology in high definition. This paperis the first of two giving an overview of available literature on various aspects of the external and internal root andcanal morphology of the mandibular first permanent molar. The aim is to provide an overview of relevant aspects of the external root morphology of the mandibular first molar in different populations. The content is supported by illustrative micro-CT images and a report on clinical cases where anomalies have been treated

Comparison of forward and reverse single-file reciprocation for root canal instrumentation in curved mandibular molar canals - a Micro-CT analysis

To compare (i) canal centering ability and transportation of Primary WaveOne Gold in combination with WaveOne Gold Glider with ProTaper Next X2 in combination with ProGlider using Micro-CT, and (ii) difference in final preparation times between these two preparation groups. Mesiobuccal canals of 50 mandibular first molars were used. Teeth were randomly divided into two preparation groups. Results were analysed using a one-way analysis of variance (ANOVA). Apically, ProGlider/ProTaper Next X2 demonstrated better centering ratio values and lower transportation values compared to WaveOne Gold Glider/Primary WaveOne Gold (p<.05). No differences were found in the mean combined centering ratios and transportation values between groups (p>.05). No statistically significant differences between the canal preparation times were found (p<.06). The combination of ProGlider /ProTaper Next X2 yields better results for transportation and centering ability apically compared to WaveOne Gold Glider in combination with Primary Wave-One Gold

Factors influencing apical debris extrusion during endodontic treatment - A review of the literature

The primary cause of a periapical inflammatory lesion is intra-radicular microbial infection. Prevention and elimination of apical periodontitis is achieved through successful endodontic treatment. Endodontic treatment is designed to maintain and restore the health of the periapical tissues and prevent periapical disease. It may be defined as the combination of mechanical instrumentation of the root canal system with bactericidal irrigation and obturation with an inert material. Technically, the goal of instrumentation and irrigation is to debride and entirely remove infected tissue debris from the root canal system and create a uniform conical shape that allows medicament delivery and adequate obturation. Microbiologically, the goal of instrumentation and irrigation is to eliminate micro-organisms, reduce their survival in the root canal system and neutralise any antigenic potential of the microbial components remaining in the canal

Evaluation of preparation times of WaveOne Gold reciprocating instruments compared to two analogous counterparts

Manufacturers are constantly developing new products to optimise endodontic treatment. These newer file systems are often associated with increasing expenditure of instrumentation and can affect the cost effectiveness of root canal treatment. Recently, companies have emerged that claim to have successfully reproduced many of the more established endodontic file systems manufactured by Dentsply Sirona (Ballaigues, Switzerland). EdgeEndo (Albuquerque, New Mexico, USA) and PacDent (Brea, CA, USA), which manufacture files similar in design to that of Dentsply Sirona, claim that they are similar and sell them at a lower price. A performance comparison of the replica file systems to their original is of clinical importance. The aim of this ex vivo study was to compare the total glide path and canal preparation times of WaveOne Gold Glider (Dentsply Sirona) combined with the Primary WaveOne Gold (Dentsply Sirona), Edge GlidePath (Edge Endo, Albuquerque, New Mexico, USA) followed by the Primary EdgeOne Fire (EdgeEndo); and One File G Glide Path (Pac-Dent, Brea, CA, USA) file combined with the Primary One File G (Pac-Dent) Shaping file. Sixty curved untreated canals of extracted, human, mandibular molars were randomly divided into three groups of 20 canals each for mechanical glide path enlargement and root canal shaping. Group 1 (WaveOne Gold Glider + Primary WaveOne Gold); Group 2 (Edge GlidePath + Primary EdgeOne Fire); and Group 3 (One File G Reciprocating Glide Path File + Primary One File G Reciprocating shaping file). The total time taken to prepare a glide path and to complete the root canal preparation of each canal was recorded (in seconds) by means of an iPhone stopwatch (Apple Inc., Cupertino, California). The time taken to change files was not recorded. Throughout the instrumentation process, RC Prep was used as a lubricant, and5 mL 3% sodium hypochlorite was used as irrigation solution. Mean and standard deviations were determined for each group, and analysis of variance was used to statistically compare the mean glide path preparation times for the three groups. The fastest final canal preparation time was achieved by WOGG/PWOG (41.78 ± 10.58 s), followed by OFGP/ POFS (42.02 ± 12.16 s) and then EGP/PEOF (42.49 ± 10.44 s). There were no statistically significant differences between the canal preparation times of the three combination groups (p>0.05)

Shaping ability of WaveOne Gold reciprocating instruments compared to two analogous counterparts

The aim of this study was to evaluate and compare canalcentering ability and transportation of three analogous reciprocating shaping instruments after glide path preparation. Radiographs were used to select sixty untreated mesiobuccal canals with curvatures of 25° to 35° from extracted, human, mandibular molars. The canals were randomly divided into three groups for glide path preparation and shaping (n = 20): Group TWOG (WaveOne Gold Glider + Primary WaveOne Gold); Group TEF (Edge GlidePath + Primary EdgeOne Fire); and Group TOFG (One File G Reciprocating Glide Path File + Primary Shaping file). Pre- and post-preparation micro-CT scans were compared at levels 7 mm (coronal), 5 mm (midroot), and 3 mm (apical) from the apex to evaluate transportation and centering ratios. There were no significant differences in centering ratios at the coronal and midroot levels (P > 0.05). Transportation values were similar at the coronal level and for the combined  mean values (P > 0.05). Transportation values for TEF and TWOG were similar (P = 0.98) at the midroot level but significantly lower than TOFG (P = 0.04). Apically, TEF remained significantly more centered with significantly lower transportation values than TWOG and TOFG (P < 0.05). Combined results showed that TEF was significantly more centered than TWOG but similar to TOFG (P = 0.017). Centering ratios and transportation values were more favorable in the apical region after use of TEF. All three groups evaluated in this study proved to be safe for the preparation of moderately curved root canals