Filling materials for retreatment of failed root canals – only very low quality evidence is available from RCTs

Composite_resin_fillng_2The living part of the tooth, also known as the tooth pulp, can become irreversibly inflamed as a result of damage or bacterial infection due to tooth decay. To deal with this problem, the dentist has to drill a hole to access the inner space of the tooth or root canal system, and remove the infected tissue and toxic irritants by a combination of mechanical cleaning and irrigation. After this is done, the dentist fills the space with an inert packing material and seals the opening. This procedure is known as root canal therapy. Although results are generally good, a small number of failures do occur. This may be attributed to the complexity of the root canal system, which has many small additional pathways communicating with each other, making it difficult to completely eliminate all of the toxins and irritants. These can spread, causing the infection around the root to last indefinitely. When root canal therapy fails, a retreatment called retrograde filling is a good alternative to save the tooth. During retrograde filling the dentist cuts a flap in the gum and creates a hole in the bone to get access to the bottom tip of the root. After cutting off the tip, then thorough preparation, the apex is sealed (the apical seal) and the hole made by the dentist filled with a dental material. This sealing process is thought to be the single most important factor in achieving success in a retrograde root filling. Many materials have been developed to seal the root tip, mineral trioxide aggregate is the material of interest at present, but there is no consensus about which material is best. Continue reading

Should root canal treatment be performed in one dental visit or over several visits?

This is an update of a review first published in 2007. Root canal treatment, or endodontic treatment, is a common procedure in dentistry. The main reasons that root canal treatment are needed are persistent inflammation of the dental pulp (pulpitis) and death of the dental pulp (dead or non-vital tooth) caused by tooth decay, cracks or chips, or other accidental damage to teeth. Root canal treatment is considered successful when there are no symptoms, for example pain, and when x-rays show no signs of damage to bone and other supporting tissues of the tooth. The success of root canal treatment depends on the preoperative condition of the tooth, as well as the endodontic procedures used. There are two approaches commonly used. In the first, the root canal treatment is performed in multiple visits to the dental clinic, and a dressing is placed in the tooth between appointments to avoid the build up of bacteria that may cause infections. In the second approach, the treatment is performed in one visit to the dental clinic. Which approach leads to less postoperative complications?

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Procedures for retreatment of failed root canal therapy

elderly-man_dental-exam-2In root canal therapy, the infected pulp of a tooth is removed, and the root cavity is disinfected and filled with a sealing material. However, if micro-organisms that caused the infection are not completely removed, after some time they may cause a disease at the tip of the root, called a periapical lesion. Treatment for this requires a second intervention, which can be performed in the same way as the first treatment, from the crown into the root canal, to remove the existing filler and clean and disinfect as well as possible before sealing again. Alternatively, should this procedure fail, or if it is not feasible, a surgical intervention can be used. Continue reading

Should you use a crown or a filling to restore a root-filled tooth?

0244 Rosario Van Tulpe

Photo by Rosario Van Tulpe, reproduced under Creative Commons licence

Root filling is a fairly routine dental procedure in which the injured or dead nerve of a tooth is removed and replaced by a root canal filling. However, the restoration of root-filled teeth can be quite challenging as these teeth tend to be weaker than healthy ones. A dentist may use crowns (restorations made outside of the mouth and then cemented into place) or conventional fillings (direct filling with materials such as amalgam or composite/plastic resin). Although crowns may help to protect root-filled teeth by covering them, conventional fillings demand less in terms of time, costs and removal of tooth structure. Continue reading

New edition of the Cochrane Library features three new reviews from the Oral Health Group

The latest edition of the Cochrane Library for September 2012 features three new reviews from the Oral Health Group.

Irrigants for non-surgical root canal treatment in mature permanent teeth
Zbys Fedorowicz, Mona Nasser, Patrick Sequeira-Byron, Raphael Freitas de Souza, Ben Carter, Marc Heft

This new systematic review examines the antiseptic and antibacterial irrigating solutions available to help to eliminate infection during root canal treatment. 11 studies were included, with 851 participants. The review concludes that there was no difference between some of the irrigants or between the different strengths of individual irrigants.

Preoperative analgesics for additional pain relief in children and adolescents having dental treatment
Paul F Ashley, Susan Parekh, David R Moles, Prabhleen Anand, Amal Behbehani

This review examines whether or not to give children painkillers before dental treatment, in order to reduce pain afterwards. Five trials were included, with 190 participants. However, the available evidence was not sufficient to determine efficacy. There was some evidence that it could be of benefit before orthodontic treatment.

Systemic interventions for recurrent aphthous stomatitis (mouth ulcers)
Paul Brocklehurst, Martin Tickle, Anne-Marie Glenny, Michael A Lewis, Michael N Pemberton, Jennifer Taylor, Tanya Walsh, Philip Riley, Julian M Yates

25 trials with 21 interventions were included in this new systematic review on recurrent mouth ulcers. No single treatment was found to be effective and the results remain inconclusive.

Other highlights of the Cochrane Library, Issue 9, 2012 are:

New Cochrane Oral Health Group Reviews and Protocols for May 2012

Issue 5, 2012 of the Cochrane Library has just been published! The Cochrane Oral Health Group has published 2 new reviews and 2 new protocols:

New review: Single crowns versus conventional fillings for the restoration of root filled teeth
Zbys Fedorowicz, Ben Carter, Raphael Freitas de Souza, Carolina de Andrade Lima Chaves, Mona Nasser, Patrick Sequeira-Byron

This new review features one trial with 117 participants, and concludes that there is currently insufficient reliable evidence on the effectiveness of these two treatments.

ImageNew review: Treatments for adults with prominent lower front teeth
Hideko Minami-Sugaya, Débora A Lentini-Oliveira, Fernando R Carvalho, Marco Antonio C Machado, Clóvis Marzola, Humberto Saconato, Gilmar F Prado

Several treatments have been proposed for this condition, including orthopedics, functional appliances, interceptive and corrective orthodontics and surgery. However, only two small trials matched the inclusion criteria for this review, and more evidence is needed to judge effectiveness.


ImageNew protocol: Interdental brushing for the management of periodontal diseases and dental caries in adults
Tina Poklepovic, Dario Sambunjak, Trevor M Johnson, Pauline Imai, Peter Tugwell, Jason W Nickerson, Jan E Clarkson, Helen V Worthington

This is a protocol for a new systematic review, which will consider the effectiveness of interdental brushing to prevent dental caries and periodontal disease, when compared to regular brushing alone.

New protocol: Rubber dam isolation for restorative treatment in dental patients
Yan Wang, Chunjie Li, He Yuan, May CM Wong, Zongdao Shi, Xuedong Zhou

This new review wil consider the effectiveness of rubber dams in isolating the dental treatment area and controlling moisture. It will compare rubber dams with other methods of isolation (for example, cotton rolls).

Other highlights of the Cochrane Library, Issue 5, 2012 include: