Dental caries is a pathology of wide prevalence in the world, and it affects the dentition in the early stages of life, being most common in susceptible populations because of a lack of dental education and limited access to quality healthcare services.18 It is well known that it is essential to avoid space loss during childhood in order to preserve the natural dentition. Loss of proper space can lead to malposition of permanent teeth and compromises nutrition, speech ability and self-confidence, among others.19 Primary molar pulpectomy is the treatment of choice to preserve primary natural dentition in teeth affected at the pulp–dentine complex and periodontally diseased as a result of bacterial invasion of the root canal system.20
Anxiety and stress regarding dental treatment in general are common, but must especially be taken into consideration when it comes to performing paediatric endodontic treatment.21 The search for and implementation of efficient endodontic techniques requires proper understanding of the root canal system anatomy, root canal instrumentation, disinfection and obturation techniques, and the importance of coronal restoration.20, 22 When it comes to root canal instrumentation, hand file techniques have been widely used in endodontics, but they are time-consuming, uncomfortable at some point and susceptible to procedural errors, especially if preformed by clinicians with limited clinical experience.22, 23 Mechanically driven instrumentation came to change the way we shape canals, providing a faster way to enlarge the root canal system in a convenient geometry to allow the appropriate movement of the irrigating solutions inside the root canal system.23, 24 Instrument design, nickel–titanium alloys and the type of movement are factors to take into consideration, because they will directly influence the instrument performance.
In paediatric dentistry, chair time is a factor to consider: the shorter, the better for the patient to manage anxiety and feel comfortable. Single-file reciprocating instrument systems can be beneficial for paediatric endodontic treatment because they properly enlarge the geometry of the root canals, facilitate good shaping to enable proper distribution of irrigating solutions all along the working length and are less time-consuming than rotary and manual instrumentation sequences.23, 25, 26 However, to the best of our knowledge, there is a lack of in vivo research on the use of reciprocating instruments in primary molar pulpectomy.
Moghaddam et al. in their experimental study compared the cleaning efficacy and instrumentation time of RECIPROC and Mtwo (VDW) in primary molars.27 They concluded that using systems such as RECIPROC for pulpectomy is beneficial. Ramazani et al. in their in vitro study compared two rotary systems and RECIPROC in mesiobuccal canals of primary molars.28 They confirmed the RECIPROC system’s fast and good cleaning and shaping ability. These were the first studies to advocate the use of the RECIPROC system in the primary dentition.
Moraes et al. conducted an in vitro study employing a 3D-printed prototype of a maxillary primary central incisor.14 They concluded that the R40 file of the RECIPROC system was effective for instrumenting their 3D-printed model.
Tyagi et al. in their in vivo study compared the use of a rotary system and the RECIPROC system for primary molar pulpectomy and evaluated the possible influence of the file system on child behaviour, among other factors.29 Their results regarding clinical performance were in accordance with those of previous research. Nonetheless, they stated that the choice of file system did not significantly alter child behaviour.
Dalzell et al. conducted a micro-CT study in which they evaluated the instrumentation efficacy of manual, Mtwo and RECIPROC blue files (VDW) in non-fused and fused primary molar roots and found significant differences in cleaning and shaping effectiveness in both fused and non-fused teeth.30 Additionally, they found more procedural errors when the reciprocating instruments were used. This last finding is contrary to those of previous research and our clinical experience so far. Although we have not seen the clinical performance of the RECIPROC blue system, it shares the geometrical design and motion of RECIPROC.
Barasuol et al. compared the shaping ability of hand, rotary and reciprocating files in primary teeth in a micro-CT in vitro study.25 Their results showed more canal transportation in the middle third of the root canal with the R25 file. They also found a shorter instrumentation time with the RECIPROC system compared with manual instrumentation.
To the best of our knowledge, ours is the first clinical report of the use of the R25 file in an in vivo scenario for primary molar pulpectomy. The long period of follow-up showed good results overall. These five cases were restored with complete stainless-steel crowns, and the time of their cementation was appropriate, avoiding recontamination of the root canal system. Our clinical experience over the years exceeds the cases reported here; however, these cases were presented because of their longer follow-up and proper stainless-steel restoration. The therapeutic success of our unreported cases follows the trend shown in this case series. Stainless-steel crowns are the preferred restoration for children at high risk of caries and teeth that have undergone pulp therapy. This may have contributed to the long-term success of treatment.
The use of the operating microscope, coupled with the experience of the operator in microscopic endodontics, may also have contributed to these results. The dental microscope is under-estimated and under-used in paediatric dentistry; however, its advantages in locating canals in primary molars are clear, and its use is likely to become the standard of practice in dentistry. The improved ergonomics also allows longer working times without repetitive muscle strain and prevents postural issues.”
More research is needed with longer follow-up and more cases and a good randomising protocol. Newer reciprocating instruments like RECIPROC blue could possess designs and metallurgical characteristics that are beneficial for use in primary molar pulpectomy and should therefore be investigated.
Do you fill the canals of the primary molars with gutta points and root canal paste, as we do for permanent teeth ?