A root canal that does not fail, and does not hurt.

The dental pulp can undergo death without pain. Such teeth, if they require a filling, cannot be treated unless a root canal is done. It is like closing a lid on a steaming pressure cooker, it will cause immense pain if the tooth is not treated by a root canal.

Root canal failures usually happen when the procedure is performed without proper isolation and magnification. If the operator does not have enough training and proper equipment, mistakes can happen that result in failure.

If the dental pulp is either dead, or if it gets exposed during removal of decay, a root canal is indicated. In young individuals, under certain conditions, a procedure called vital pulp therapy can be performed instead for an exposed pulp.

Dental decay is a combination of four things: bacteria that consume carbohydrates, on a tooth surface, for a sufficient amount of time. Decay is also slow, and takes up to four years to show as a large cavity, so you may have given up sugar a year ago and the decay had already started. Carbohydrates are also present in a modern diet without us knowing, and the frequency of consumption does more damage than a large quantity at one time.

A root canal treats the diseased, painful or dead pulp inside a tooth. The pulp is the tissue that senses hot and cold and nourishes the tooth. The disease is caused by dental decay carrying bacteria from the mouth into the pulp. If treatment is delayed, the diseased pulp either causes a great deal of pain, or it dies and causes infection.

The usual signs are pain, or sensitivity to hot and cold that lingers. But a tooth can also need one with no pain at all: the pulp can die quietly, and a tooth in that state cannot simply be filled. It is like closing a lid on a steaming pressure cooker, it will cause immense pain later if it is not treated properly now.

The success rate is 95 to 100%. If the tooth already has infection in it that falls to about 85 to 90%, which does not reduce how worthwhile the procedure is. Those figures are for periods exceeding ten years.

A root canal keeps your own tooth, and at 95 to 100% success over ten years and beyond it usually keeps it in function indefinitely. Replacing an extracted tooth is a bigger undertaking: a dental implant with a crown starts at PKR 170,000 against PKR 48,000 for the root canal, and takes at least three months for the bone to grow around the implant. Extraction is the right answer when a tooth genuinely cannot be saved, not as a shortcut.

Failures usually happen when the procedure is done without proper isolation and magnification. If bacteria are still present in the canals when the root canal is completed, it will fail. Moisture during filling causes the filling to fail. And a dentist working without a rubber dam cannot use the strong disinfectants that clean the inside of the tooth, because they taste extremely bad, which is exactly why root canals done without one fail more often. Beyond that, an operator without enough training or the right equipment can make mistakes that cause a failure.

It gives complete isolation of the tooth. The bacteria in saliva, and the moisture itself, do not get inside the tooth, we are already fighting the bacteria in there and do not need more. It is also what makes strong disinfectants usable at all. In much of the developed world a root canal specialist can be sued for not using one.

In dentistry, vision is everything: you do more if you see more. Canals are not missed and decay can be removed completely. A microscope also lets a dentist go beyond routine procedures, because objects a fraction of a millimetre across are simply not visible to the naked eye. Magnification here runs up to 22 to 24 times, and unlike a loupe it can be varied and gives real depth perception, with a very bright light down into the tooth.

It was a revolution in endodontics when it arrived in the late 1990s. It reached Pakistan in the early 2000s and Prof. Dr. Arshad Hasan was one of the early adopters. Before it, root canals were prepared with manual instruments over several visits. Today rotary NiTi instruments are made to save teeth in a very conservative way, so patients keep them for longer.