Labial access to lower incisors. review of literature and clinical practice.

Straight line access to root canals is one of the most important factors in modern endodontics. (S.Patel & J . Rhodes British dental Journal 203). It prevents instruments from working under high stress and helps to avoid separation. This will also prevent iatrogenic mistakes like ledging, zipping perforations, and separations of instruments, Generally for most of the teeth straight line access is easy done especially when working with magnification and under the rubber dam. For lower incisors however there are still not clear guidelines on how to approach root canal treatment and so far lingual access is very popular . In my clinical practice sine over 10 years all root canal treatments are done with the use of the microscope. Initially lower incisors were treated with lingual access, the way I was taught in dental school .This however provided poor visualization of the root canal system and I was hardly able to find and never able to clearly see 2 canals, This was frustrating that I was not gaining much from using microscope in this situation. This made me think that there must be better way of doing rct in lower incisors and visualize both canals especially since about 40% of lower incisors present 2 canals . Those are located in labial and lingual direction. Early articles that I managed to find via simply google search help a lot. First in 1985 clinicians LaTurno SA, Zillich RM quoted that “ A radiographic analysis of lower incisors conclude that a more labial orientation of the access opening would provide straight-line access to the canal more consistently than the "traditional" lingual access opening. The more labial placement of the access opening on mandibular anterior teeth will make endodontic treatment more efficient and may, therefore, increase endodontic success rates in these teeth”. Next in 1989 Madjar D, Kusner W, Shifman A. wrote that labial endodontic access is an alternative to the conventional lingual endodontic access in permanent teeth. The labial approach facilitates visibility and provides direct access to the root apex. Current restorative procedures offer improved methods to overcome the esthetic impairment resulting from this approach. Labial access is especially beneficial for patients with limited mandibular opening. Another research done by clinicians Clements RE, Gilboe DB.in Canada in 1991 on access for root canal treatment for lower incisors says that this approach facilitates the identification and instrumentation of two canals, if present, and enhances achievement of complete obturation. More coronal tooth structure is preserved, enabling an optimum core design for bracing the root.

As a result of searching and reading about alternative access my clinical practice has changed dramatically and since then all lower incisors are treated with labial access, Surprisingly none of the patients ever questioned why tooth is accessed from visible side and none of the patient had any aesthetic complains after finished root canal treatment . I believe this is because wide selection of composite materials and constantly developing techniques for use of composite materials helps to make access cavity invisible. I would like to show a case treated few years ago and reviewed recently. Review x-ray shows excellent healing of large apical lesion thanks to good access to apical

area during treatment, I would 100% say that labial access was the most helpful here and I could only get this result due to alternative modern approach.Use of the Zeiss microsocpe and rotary instruments from Dentsply was great help as well.

If we analyze lower incisor anatomy radiologically we can see that labial access provides straight line access.

And if we draw a line on the x-rays from apex to coronal part it shows that access cavity projects labially in those teeth.

Surprisingly all new VT’s that I had a chance to meet on my endodontic study days in GDH post grad centre are quite surprised when asked about labial access.This is something that they never have heard of.I am happy to say that most of them after study day and short exercise on extracted teeth are happy to give it a go for their patients. All say that this is a lot simpler and they will be able to restore access cavity with composite material.

I hope this short article and few pictures can open the minds to other clinician and help to achieve better results in endodontics.